From 213915b74b47767874648fd58acb0377fc102fd0 Mon Sep 17 00:00:00 2001
From: AndyJado <101876416+AndyJado@users.noreply.github.com>
Date: Sat, 20 Aug 2022 18:38:42 +0800
Subject: [PATCH 01/10] migrate some `rustc_borrowck` diagnostic

---
 compiler/rustc_borrowck/src/lib.rs            | 19 ++++++--------
 .../src/region_infer/opaque_types.rs          | 18 ++++++-------
 .../rustc_borrowck/src/session_diagnostics.rs | 25 ++++++++++++++++++-
 .../locales/en-US/borrowck.ftl                | 13 +++++++++-
 4 files changed, 50 insertions(+), 25 deletions(-)

diff --git a/compiler/rustc_borrowck/src/lib.rs b/compiler/rustc_borrowck/src/lib.rs
index 4ad9a970bc1be..2828b972c5f99 100644
--- a/compiler/rustc_borrowck/src/lib.rs
+++ b/compiler/rustc_borrowck/src/lib.rs
@@ -18,7 +18,7 @@ extern crate tracing;
 
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::graph::dominators::Dominators;
-use rustc_errors::{Applicability, Diagnostic, DiagnosticBuilder, ErrorGuaranteed};
+use rustc_errors::{Diagnostic, DiagnosticBuilder, ErrorGuaranteed};
 use rustc_hir as hir;
 use rustc_hir::def_id::LocalDefId;
 use rustc_index::bit_set::ChunkedBitSet;
@@ -424,17 +424,12 @@ fn do_mir_borrowck<'a, 'tcx>(
             continue;
         }
 
-        tcx.struct_span_lint_hir(UNUSED_MUT, lint_root, span, |lint| {
-            let mut_span = tcx.sess.source_map().span_until_non_whitespace(span);
-            lint.build("variable does not need to be mutable")
-                .span_suggestion_short(
-                    mut_span,
-                    "remove this `mut`",
-                    "",
-                    Applicability::MachineApplicable,
-                )
-                .emit();
-        })
+        tcx.emit_spanned_lint(
+            UNUSED_MUT,
+            lint_root,
+            span,
+            session_diagnostics::VarBetterNotMut { span },
+        )
     }
 
     let tainted_by_errors = mbcx.emit_errors();
diff --git a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs
index d6712b6a4799c..b0d7253651b09 100644
--- a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs
+++ b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs
@@ -16,6 +16,8 @@ use rustc_span::Span;
 use rustc_trait_selection::traits::error_reporting::InferCtxtExt as _;
 use rustc_trait_selection::traits::TraitEngineExt as _;
 
+use crate::session_diagnostics::ConstNotUsedTraitAlias;
+
 use super::RegionInferenceContext;
 
 impl<'tcx> RegionInferenceContext<'tcx> {
@@ -639,17 +641,11 @@ impl<'tcx> TypeFolder<'tcx> for ReverseMapper<'tcx> {
                     Some(GenericArgKind::Const(c1)) => c1,
                     Some(u) => panic!("const mapped to unexpected kind: {:?}", u),
                     None => {
-                        self.tcx
-                            .sess
-                            .struct_span_err(
-                                self.span,
-                                &format!(
-                                    "const parameter `{}` is part of concrete type but not \
-                                          used in parameter list for the `impl Trait` type alias",
-                                    ct
-                                ),
-                            )
-                            .emit();
+                        //FIXME!
+                        self.tcx.sess.emit_err(ConstNotUsedTraitAlias {
+                            ct: ct.to_string(),
+                            span: self.span,
+                        });
 
                         self.tcx().const_error(ct.ty())
                     }
diff --git a/compiler/rustc_borrowck/src/session_diagnostics.rs b/compiler/rustc_borrowck/src/session_diagnostics.rs
index 895723d44ff1b..c879988b76af4 100644
--- a/compiler/rustc_borrowck/src/session_diagnostics.rs
+++ b/compiler/rustc_borrowck/src/session_diagnostics.rs
@@ -1,7 +1,15 @@
-use rustc_macros::{SessionDiagnostic, SessionSubdiagnostic};
+use rustc_macros::{LintDiagnostic, SessionDiagnostic, SessionSubdiagnostic};
 use rustc_middle::ty::Ty;
 use rustc_span::Span;
 
+#[derive(SessionDiagnostic)]
+#[error(borrowck::move_borrowed, code = "E0505")]
+pub(crate) struct MoveBorrowed<'cx> {
+    #[primary_span]
+    pub span: Span,
+    pub desc: &'cx str,
+}
+
 #[derive(SessionDiagnostic)]
 #[error(borrowck::move_unsized, code = "E0161")]
 pub(crate) struct MoveUnsized<'tcx> {
@@ -42,3 +50,18 @@ pub(crate) struct GenericDoesNotLiveLongEnough {
     #[primary_span]
     pub span: Span,
 }
+
+#[derive(LintDiagnostic)]
+#[lint(borrowck::var_better_not_mut)]
+pub(crate) struct VarBetterNotMut {
+    #[suggestion_short(applicability = "machine-applicable", code = "")]
+    pub span: Span,
+}
+
+#[derive(SessionDiagnostic)]
+#[error(borrowck::const_not_used_in_type_alias)]
+pub(crate) struct ConstNotUsedTraitAlias {
+    pub ct: String,
+    #[primary_span]
+    pub span: Span,
+}
diff --git a/compiler/rustc_error_messages/locales/en-US/borrowck.ftl b/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
index 4af40d2062d3a..51f174df44d06 100644
--- a/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
+++ b/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
@@ -15,4 +15,15 @@ borrowck_higher_ranked_subtype_error =
     higher-ranked subtype error
   
 generic_does_not_live_long_enough =
-    `{$kind}` does not live long enough
\ No newline at end of file
+    `{$kind}` does not live long enough
+    
+borrowck_move_borrowed = 
+    cannot move out of `{$desc}` beacause it is borrowed
+    
+borrowck_var_better_not_mut = 
+    variable does not need to be mutable
+    .suggestion = remove this `mut`
+
+borrowck_const_not_used_in_type_alias = 
+    const parameter `{$ct}` is part of concrete type but not \
+          used in parameter list for the `impl Trait` type alias

From 2ad89c9768e94f0c4701b5268044391b3cb93730 Mon Sep 17 00:00:00 2001
From: AndyJado <101876416+AndyJado@users.noreply.github.com>
Date: Sun, 21 Aug 2022 12:11:21 +0800
Subject: [PATCH 02/10] fluent / remove

---
 compiler/rustc_error_messages/locales/en-US/borrowck.ftl | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/compiler/rustc_error_messages/locales/en-US/borrowck.ftl b/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
index 51f174df44d06..a5ce441f4a787 100644
--- a/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
+++ b/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
@@ -25,5 +25,4 @@ borrowck_var_better_not_mut =
     .suggestion = remove this `mut`
 
 borrowck_const_not_used_in_type_alias = 
-    const parameter `{$ct}` is part of concrete type but not \
-          used in parameter list for the `impl Trait` type alias
+    const parameter `{$ct}` is part of concrete type but not used in parameter list for the `impl Trait` type alias

From 5629970e724723f0ed3310e7269adeb202dcf66c Mon Sep 17 00:00:00 2001
From: AndyJado <101876416+AndyJado@users.noreply.github.com>
Date: Sun, 21 Aug 2022 22:24:42 +0800
Subject: [PATCH 03/10] region_err

---
 .../src/diagnostics/region_errors.rs          | 95 +++++++++----------
 .../rustc_borrowck/src/session_diagnostics.rs | 75 +++++++++++++++
 .../locales/en-US/borrowck.ftl                | 29 ++++++
 3 files changed, 148 insertions(+), 51 deletions(-)

diff --git a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
index 0dce5be953e1a..d28187dc42de4 100644
--- a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
@@ -1,3 +1,5 @@
+#![deny(rustc::untranslatable_diagnostic)]
+#![deny(rustc::diagnostic_outside_of_impl)]
 //! Error reporting machinery for lifetime errors.
 
 use rustc_data_structures::fx::FxHashSet;
@@ -23,7 +25,10 @@ use rustc_span::symbol::{kw, sym, Ident};
 use rustc_span::Span;
 
 use crate::borrowck_errors;
-use crate::session_diagnostics::GenericDoesNotLiveLongEnough;
+use crate::session_diagnostics::{
+    FnMutError, FnMutReturnTypeErr, GenericDoesNotLiveLongEnough, LifeTimeOutLiveErr,
+    LifeTimeReturnCategoryErr,
+};
 
 use super::{OutlivesSuggestionBuilder, RegionName};
 use crate::region_infer::BlameConstraint;
@@ -488,12 +493,6 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
     ) -> DiagnosticBuilder<'tcx, ErrorGuaranteed> {
         let ErrorConstraintInfo { outlived_fr, span, .. } = errci;
 
-        let mut diag = self
-            .infcx
-            .tcx
-            .sess
-            .struct_span_err(*span, "captured variable cannot escape `FnMut` closure body");
-
         let mut output_ty = self.regioncx.universal_regions().unnormalized_output_ty;
         if let ty::Opaque(def_id, _) = *output_ty.kind() {
             output_ty = self.infcx.tcx.type_of(def_id)
@@ -501,19 +500,21 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
 
         debug!("report_fnmut_error: output_ty={:?}", output_ty);
 
-        let message = match output_ty.kind() {
-            ty::Closure(_, _) => {
-                "returns a closure that contains a reference to a captured variable, which then \
-                 escapes the closure body"
-            }
+        let ty_err = match output_ty.kind() {
+            ty::Closure(_, _) => FnMutReturnTypeErr::ReturnClosure { span: *span },
             ty::Adt(def, _) if self.infcx.tcx.is_diagnostic_item(sym::gen_future, def.did()) => {
-                "returns an `async` block that contains a reference to a captured variable, which then \
-                 escapes the closure body"
+                FnMutReturnTypeErr::ReturnAsyncBlock { span: *span }
             }
-            _ => "returns a reference to a captured variable which escapes the closure body",
+            _ => FnMutReturnTypeErr::ReturnRef { span: *span },
         };
 
-        diag.span_label(*span, message);
+        let mut err = FnMutError {
+            span: *span,
+            ty_err,
+            upvar_def_span: None,
+            upvar_span: None,
+            fr_span: None,
+        };
 
         if let ReturnConstraint::ClosureUpvar(upvar_field) = kind {
             let def_id = match self.regioncx.universal_regions().defining_ty {
@@ -532,20 +533,17 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                 let upvars_map = self.infcx.tcx.upvars_mentioned(def_id).unwrap();
                 let upvar_def_span = self.infcx.tcx.hir().span(def_hir);
                 let upvar_span = upvars_map.get(&def_hir).unwrap().span;
-                diag.span_label(upvar_def_span, "variable defined here");
-                diag.span_label(upvar_span, "variable captured here");
+                err.upvar_def_span = Some(upvar_def_span);
+                err.upvar_span = Some(upvar_span);
             }
         }
 
         if let Some(fr_span) = self.give_region_a_name(*outlived_fr).unwrap().span() {
-            diag.span_label(fr_span, "inferred to be a `FnMut` closure");
+            err.fr_span = Some(fr_span);
         }
 
-        diag.note(
-            "`FnMut` closures only have access to their captured variables while they are \
-             executing...",
-        );
-        diag.note("...therefore, they cannot allow references to captured variables to escape");
+        let mut diag = self.infcx.tcx.sess.create_err(err);
+
         self.suggest_move_on_borrowing_closure(&mut diag);
 
         diag
@@ -681,39 +679,33 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
             ..
         } = errci;
 
-        let mut diag =
-            self.infcx.tcx.sess.struct_span_err(*span, "lifetime may not live long enough");
-
         let (_, mir_def_name) =
             self.infcx.tcx.article_and_description(self.mir_def_id().to_def_id());
 
         let fr_name = self.give_region_a_name(*fr).unwrap();
-        fr_name.highlight_region_name(&mut diag);
         let outlived_fr_name = self.give_region_a_name(*outlived_fr).unwrap();
-        outlived_fr_name.highlight_region_name(&mut diag);
 
-        match (category, outlived_fr_is_local, fr_is_local) {
-            (ConstraintCategory::Return(_), true, _) => {
-                diag.span_label(
-                    *span,
-                    format!(
-                        "{mir_def_name} was supposed to return data with lifetime `{outlived_fr_name}` but it is returning \
-                         data with lifetime `{fr_name}`",
-                    ),
-                );
-            }
-            _ => {
-                diag.span_label(
-                    *span,
-                    format!(
-                        "{}requires that `{}` must outlive `{}`",
-                        category.description(),
-                        fr_name,
-                        outlived_fr_name,
-                    ),
-                );
-            }
-        }
+        let err_category = match (category, outlived_fr_is_local, fr_is_local) {
+            (ConstraintCategory::Return(_), true, _) => LifeTimeReturnCategoryErr::WrongReturn {
+                span: *span,
+                mir_def_name: mir_def_name.to_string(),
+                outlived_fr_name: outlived_fr_name.to_string(),
+                fr_name: fr_name.to_string(),
+            },
+            _ => LifeTimeReturnCategoryErr::ShortReturn {
+                span: *span,
+                category_desc: category.description().to_string(),
+                free_region_name: fr_name.to_string(),
+                outlived_fr_name: outlived_fr_name.to_string(),
+            },
+        };
+
+        let err = LifeTimeOutLiveErr { span: *span, category: err_category };
+
+        let mut diag = self.infcx.tcx.sess.create_err(err);
+
+        fr_name.highlight_region_name(&mut diag);
+        outlived_fr_name.highlight_region_name(&mut diag);
 
         self.add_static_impl_trait_suggestion(&mut diag, *fr, fr_name, *outlived_fr);
         self.suggest_adding_lifetime_params(&mut diag, *fr, *outlived_fr);
@@ -862,6 +854,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                     ident.span,
                     "calling this method introduces the `impl`'s 'static` requirement",
                 );
+                // TODO!
                 err.span_note(multi_span, "the used `impl` has a `'static` requirement");
                 err.span_suggestion_verbose(
                     span.shrink_to_hi(),
diff --git a/compiler/rustc_borrowck/src/session_diagnostics.rs b/compiler/rustc_borrowck/src/session_diagnostics.rs
index c879988b76af4..3a24b28da3556 100644
--- a/compiler/rustc_borrowck/src/session_diagnostics.rs
+++ b/compiler/rustc_borrowck/src/session_diagnostics.rs
@@ -1,3 +1,4 @@
+use rustc_errors::MultiSpan;
 use rustc_macros::{LintDiagnostic, SessionDiagnostic, SessionSubdiagnostic};
 use rustc_middle::ty::Ty;
 use rustc_span::Span;
@@ -65,3 +66,77 @@ pub(crate) struct ConstNotUsedTraitAlias {
     #[primary_span]
     pub span: Span,
 }
+
+#[derive(SessionDiagnostic)]
+#[error(borrowck::var_cannot_escape_closure)]
+#[note]
+#[note(borrowck::cannot_escape)]
+pub(crate) struct FnMutError {
+    #[primary_span]
+    pub span: Span,
+    #[subdiagnostic]
+    pub ty_err: FnMutReturnTypeErr,
+    #[label(borrowck::upvar_def)]
+    pub upvar_def_span: Option<Span>,
+    #[label(borrowck::upvar)]
+    pub upvar_span: Option<Span>,
+    #[label(borrowck::fr)]
+    pub fr_span: Option<Span>,
+}
+
+#[derive(SessionSubdiagnostic)]
+pub(crate) enum FnMutReturnTypeErr {
+    #[label(borrowck::returned_closure_escaped)]
+    ReturnClosure {
+        #[primary_span]
+        span: Span,
+    },
+    #[label(borrowck::returned_async_block_escaped)]
+    ReturnAsyncBlock {
+        #[primary_span]
+        span: Span,
+    },
+    #[label(borrowck::returned_ref_escaped)]
+    ReturnRef {
+        #[primary_span]
+        span: Span,
+    },
+}
+
+#[derive(SessionDiagnostic)]
+#[error(borrowck::lifetime_constraints_error)]
+pub(crate) struct LifeTimeOutLiveErr {
+    #[primary_span]
+    pub span: Span,
+    #[subdiagnostic]
+    pub category: LifeTimeReturnCategoryErr,
+}
+
+#[derive(SessionSubdiagnostic)]
+pub(crate) enum LifeTimeReturnCategoryErr {
+    #[label(borrowck::returned_lifetime_wrong)]
+    WrongReturn {
+        #[primary_span]
+        span: Span,
+        mir_def_name: String,
+        outlived_fr_name: String,
+        fr_name: String,
+    },
+    #[label(borrowck::returned_lifetime_short)]
+    ShortReturn {
+        #[primary_span]
+        span: Span,
+        category_desc: String,
+        free_region_name: String,
+        outlived_fr_name: String,
+    },
+}
+
+#[derive(SessionSubdiagnostic)]
+pub(crate) enum StaticLifeTimeRequireErr {
+    #[note(borrowck::impl_require_static)]
+    UsedImpl {
+        #[primary_span]
+        span: MultiSpan,
+    },
+}
diff --git a/compiler/rustc_error_messages/locales/en-US/borrowck.ftl b/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
index a5ce441f4a787..02db2fae7c46e 100644
--- a/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
+++ b/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
@@ -26,3 +26,32 @@ borrowck_var_better_not_mut =
 
 borrowck_const_not_used_in_type_alias = 
     const parameter `{$ct}` is part of concrete type but not used in parameter list for the `impl Trait` type alias
+    
+borrowck_var_cannot_escape_closure = 
+    captured variable cannot escape `FnMut` closure body
+    .upvar_def = variable defined here
+    .upvar = variable captured here
+    .fr =  "inferred to be a `FnMut` closure"
+    .note = `FnMut` closures only have access to their captured variables while they are executing...
+    .cannot_escape = ...therefore, they cannot allow references to captured variables to escape
+
+borrowck_returned_closure_escaped = 
+    returns a closure that contains a reference to a captured variable, which then escapes the closure body
+
+borrowck_returned_async_block_escaped = 
+    returns an `async` block that contains a reference to a captured variable, which then escapes the closure body
+
+borrowck_returned_ref_escaped = 
+    returns a reference to a captured variable which escapes the closure body
+
+borrowck_lifetime_constraints_error =
+    lifetime may not live long enough
+    
+borrowck_returned_lifetime_wrong =
+    {$mir_def_name} was supposed to return data with lifetime `{$outlived_fr_name}` but it is returning data with lifetime `{$fr_name}`
+
+borrowck_returned_lifetime_short =
+    {$category_desc}requires that `{$free_region_name}` must outlive `{$outlived_fr_name}`"
+    
+borrowck_impl_require_static =
+    the used `impl` has a `'static` requirement
\ No newline at end of file

From d35c9ac668ef712272cfc0d6b5aa10e17c205272 Mon Sep 17 00:00:00 2001
From: AndyJado <101876416+AndyJado@users.noreply.github.com>
Date: Mon, 22 Aug 2022 15:56:40 +0800
Subject: [PATCH 04/10] more diag migrate

---
 .gitignore                                    |   1 +
 Cargo.lock                                    |   4 +-
 compiler/rustc_arena/src/lib.rs               |   2 +-
 compiler/rustc_ast/src/ast.rs                 |  12 +-
 compiler/rustc_ast/src/ast_traits.rs          |  47 +-
 compiler/rustc_ast/src/attr/mod.rs            |   3 +-
 compiler/rustc_ast/src/mut_visit.rs           |  34 +-
 compiler/rustc_ast_lowering/src/expr.rs       |  50 +-
 .../src/diagnostics/region_errors.rs          |   1 -
 compiler/rustc_borrowck/src/lib.rs            |   9 +-
 .../src/region_infer/opaque_types.rs          |   1 -
 .../rustc_borrowck/src/session_diagnostics.rs |  36 +-
 .../src/type_check/canonical.rs               |   7 +-
 .../src/type_check/free_region_relations.rs   |   2 +-
 compiler/rustc_borrowck/src/type_check/mod.rs | 139 ++--
 compiler/rustc_builtin_macros/src/asm.rs      |   2 +-
 .../src/assert/context.rs                     |   3 +-
 compiler/rustc_builtin_macros/src/cfg.rs      |   4 +-
 .../src/deriving/clone.rs                     |   2 +-
 .../src/deriving/cmp/eq.rs                    |   2 +-
 .../src/deriving/cmp/ord.rs                   |   2 +-
 .../src/deriving/cmp/partial_eq.rs            |   2 +-
 .../src/deriving/cmp/partial_ord.rs           |   2 +-
 .../src/deriving/debug.rs                     |   2 +-
 .../src/deriving/decodable.rs                 |   2 +-
 .../src/deriving/default.rs                   |   6 +-
 .../src/deriving/encodable.rs                 |   4 +-
 .../src/deriving/generic/mod.rs               |   6 +-
 .../rustc_builtin_macros/src/deriving/hash.rs |   4 +-
 .../rustc_builtin_macros/src/deriving/mod.rs  |   2 +-
 .../src/global_allocator.rs                   |   6 +-
 .../src/proc_macro_harness.rs                 |   2 +-
 .../src/standard_library_imports.rs           |   4 +-
 compiler/rustc_builtin_macros/src/test.rs     |   5 +-
 .../rustc_builtin_macros/src/test_harness.rs  |   8 +-
 .../example/alloc_system.rs                   |   2 +-
 .../rustc_codegen_gcc/example/alloc_system.rs |   2 +-
 compiler/rustc_const_eval/src/errors.rs       |  18 +-
 .../rustc_data_structures/src/map_in_place.rs | 127 ++--
 .../rustc_data_structures/src/thin_vec.rs     |  45 ++
 compiler/rustc_driver/src/lib.rs              |   2 +-
 .../locales/en-US/borrowck.ftl                |  30 +-
 .../locales/en-US/expand.ftl                  |   6 +-
 .../rustc_errors/src/diagnostic_builder.rs    |  30 +
 compiler/rustc_errors/src/lib.rs              |   9 +
 compiler/rustc_expand/src/base.rs             |   4 +-
 compiler/rustc_expand/src/build.rs            |   6 +-
 compiler/rustc_expand/src/config.rs           |   8 +-
 compiler/rustc_expand/src/errors.rs           |  12 +-
 compiler/rustc_expand/src/expand.rs           |  16 +-
 compiler/rustc_expand/src/module.rs           |   8 +-
 compiler/rustc_expand/src/placeholders.rs     |   2 +-
 .../src/infer/error_reporting/mod.rs          |  10 +-
 .../mismatched_static_lifetime.rs             |   3 +-
 .../nice_region_error/placeholder_error.rs    |   5 +-
 .../nice_region_error/static_impl_trait.rs    |   2 +-
 .../src/infer/error_reporting/note.rs         |   4 +-
 .../src/infer/outlives/obligations.rs         |   3 +-
 compiler/rustc_interface/src/passes.rs        |   4 +-
 compiler/rustc_lint/src/types.rs              |   2 +-
 .../rustc_llvm/llvm-wrapper/PassWrapper.cpp   |  25 +-
 .../src/diagnostics/diagnostic.rs             |  82 +--
 .../src/diagnostics/diagnostic_builder.rs     |  87 ++-
 compiler/rustc_macros/src/diagnostics/mod.rs  |   4 +-
 compiler/rustc_macros/src/lib.rs              |   8 +-
 compiler/rustc_middle/src/traits/mod.rs       |  16 +-
 compiler/rustc_middle/src/ty/generics.rs      |  15 +
 compiler/rustc_monomorphize/src/collector.rs  |  12 +-
 compiler/rustc_parse/src/lib.rs               |   4 +-
 compiler/rustc_parse/src/parser/attr.rs       |   8 +-
 .../rustc_parse/src/parser/attr_wrapper.rs    |  17 +-
 .../rustc_parse/src/parser/diagnostics.rs     |  18 +-
 compiler/rustc_parse/src/parser/expr.rs       |  24 +-
 compiler/rustc_parse/src/parser/generics.rs   |  14 +-
 compiler/rustc_parse/src/parser/item.rs       |  57 +-
 compiler/rustc_parse/src/parser/pat.rs        |   8 +-
 compiler/rustc_parse/src/parser/stmt.rs       |  16 +-
 compiler/rustc_passes/src/errors.rs           | 171 +++--
 compiler/rustc_privacy/src/errors.rs          |  14 +-
 compiler/rustc_serialize/src/serialize.rs     |   2 +-
 compiler/rustc_session/src/parse.rs           |  10 +-
 compiler/rustc_span/src/lib.rs                |  10 +
 .../src/traits/error_reporting/mod.rs         |  28 +-
 .../error_reporting/on_unimplemented.rs       |   4 +-
 .../src/traits/error_reporting/suggestions.rs | 231 ++++---
 .../rustc_trait_selection/src/traits/mod.rs   |  14 +-
 .../rustc_trait_selection/src/traits/util.rs  |  25 +-
 .../rustc_trait_selection/src/traits/wf.rs    |   2 +-
 compiler/rustc_transmute/src/lib.rs           |   2 +
 .../rustc_typeck/src/check/compare_method.rs  |   2 +-
 .../rustc_typeck/src/check/fn_ctxt/_impl.rs   |  70 +-
 .../rustc_typeck/src/check/fn_ctxt/checks.rs  | 602 ++++++++++++------
 .../rustc_typeck/src/check/method/confirm.rs  |  14 +-
 compiler/rustc_typeck/src/check/method/mod.rs |   7 +-
 .../rustc_typeck/src/check/method/probe.rs    |   7 +-
 compiler/rustc_typeck/src/errors.rs           |  54 +-
 library/alloc/src/alloc/tests.rs              |   2 +-
 .../alloc/src/collections/vec_deque/mod.rs    |   4 +-
 library/alloc/src/ffi/c_str.rs                |   6 +-
 library/alloc/src/slice.rs                    |   6 +-
 library/alloc/src/vec/in_place_collect.rs     |   2 +-
 library/alloc/src/vec/into_iter.rs            |   6 +-
 library/alloc/src/vec/mod.rs                  |  14 +-
 library/alloc/src/vec/spec_extend.rs          |   2 +-
 library/alloc/tests/str.rs                    |  10 +-
 library/core/src/intrinsics.rs                |   4 +-
 library/core/src/num/f32.rs                   |  13 +-
 library/core/src/num/f64.rs                   |  13 +-
 library/core/src/slice/mod.rs                 |  15 +-
 library/core/src/slice/sort.rs                |  36 +-
 library/core/src/str/validations.rs           |   4 +-
 library/core/src/sync/atomic.rs               |  14 +-
 library/panic_abort/src/android.rs            |   2 +-
 library/panic_unwind/src/dwarf/eh.rs          |   2 +-
 library/std/src/os/unix/net/addr.rs           |   2 +-
 library/std/src/process.rs                    |  10 +-
 .../std/src/sys/sgx/abi/usercalls/tests.rs    |   4 +-
 library/std/src/sys/windows/alloc.rs          |   4 +-
 library/std/src/sys/windows/fs.rs             |   6 +-
 library/std/src/sys/windows/os.rs             |   6 +-
 src/bootstrap/bin/rustc.rs                    |  15 +-
 src/bootstrap/builder.rs                      |   2 +-
 src/librustdoc/Cargo.toml                     |   2 +-
 src/librustdoc/clean/auto_trait.rs            |  12 +-
 src/librustdoc/clean/inline.rs                |   4 +-
 src/librustdoc/clean/mod.rs                   |  35 +-
 src/librustdoc/clean/types.rs                 |  35 +-
 src/librustdoc/formats/cache.rs               |   2 +-
 src/librustdoc/html/format.rs                 |   7 +-
 src/librustdoc/html/highlight.rs              | 224 ++++---
 .../html/highlight/fixtures/decorations.html  |   6 +-
 .../html/highlight/fixtures/sample.html       |  15 +-
 .../html/highlight/fixtures/sample.rs         |   1 +
 src/librustdoc/html/highlight/tests.rs        |   7 +-
 src/librustdoc/html/render/mod.rs             |   4 +-
 src/librustdoc/json/conversions.rs            |   6 +-
 .../assembly/x86_64-floating-point-clamp.rs   |  25 +
 src/test/codegen/pic-relocation-model.rs      |   2 +-
 src/test/codegen/pie-relocation-model.rs      |   2 +-
 src/test/rustdoc/issue-41783.codeblock.html   |   4 +-
 src/test/rustdoc/issue-41783.rs               |   6 +-
 .../ui-fulldeps/internal-lints/diagnostics.rs |   2 +-
 src/test/ui-fulldeps/pprust-expr-roundtrip.rs |   5 +-
 .../session-diagnostic/diagnostic-derive.rs   | 211 +++---
 .../diagnostic-derive.stderr                  | 338 +++++-----
 .../associated-types-eq-3.stderr              |   4 +-
 .../associated-types-path-2.stderr            |  10 +-
 .../issue-27675-unchecked-bounds.stderr       |   6 +-
 .../issue-67252-unnamed-future.stderr         |  10 +-
 src/test/ui/async-await/issue-68112.stderr    |  14 +-
 .../issue-65436-raw-ptr-not-send.stderr       |  10 +-
 ...ault-trait-impl-constituent-types-2.stderr |   4 +-
 ...ypeck-default-trait-impl-precedence.stderr |   4 +-
 src/test/ui/chalkify/type_wf.rs               |   4 +-
 src/test/ui/chalkify/type_wf.stderr           |   6 +-
 .../closure_context/issue-26046-fn-mut.stderr |   2 +
 .../issue-26046-fn-once.stderr                |   2 +
 .../closure-origin-array-diagnostics.stderr   |  10 +-
 .../closure-origin-tuple-diagnostics.stderr   |  10 +-
 src/test/ui/closures/closure-move-sync.stderr |  18 +-
 .../ui/closures/closure-wrong-kind.stderr     |  10 +-
 .../defaults/trait_objects_fail.stderr        |   8 +-
 .../abstract-const-as-cast-3.stderr           |  16 +-
 .../ui/consts/const-block-const-bound.stderr  |   4 +-
 src/test/ui/derives/deriving-copyclone.stderr |   6 +-
 ...e-21659-show-relevant-trait-impls-1.stderr |   6 +-
 ...e-21659-show-relevant-trait-impls-2.stderr |   6 +-
 src/test/ui/error-codes/E0277-2.stderr        |   4 +-
 .../ui/extern/extern-types-unsized.stderr     |  12 +-
 .../feature-gate-unsized_fn_params.stderr     |   4 +-
 src/test/ui/fmt/send-sync.stderr              |  12 +-
 .../drop-tracking-parent-expression.stderr    |  12 +-
 src/test/ui/generator/drop-yield-twice.stderr |  12 +-
 ...erator-yielding-or-returning-itself.stderr |  26 +-
 src/test/ui/generator/issue-68112.rs          |   1 +
 src/test/ui/generator/issue-68112.stderr      |  10 +-
 src/test/ui/generator/not-send-sync.stderr    |  26 +-
 src/test/ui/generator/partial-drop.stderr     |  39 +-
 .../print/generator-print-verbose-1.stderr    |  10 +-
 .../print/generator-print-verbose-2.stderr    |  26 +-
 .../bugs/issue-88460.stderr                   |   6 +-
 .../issue-62529-3.stderr                      |   6 +-
 src/test/ui/inference/issue-71732.stderr      |   6 +-
 src/test/ui/inference/issue-86162-1.stderr    |   2 +-
 src/test/ui/inference/issue-86162-2.stderr    |   2 +-
 .../interior-mutability.stderr                |   6 +-
 src/test/ui/issues/issue-20162.stderr         |   6 +-
 src/test/ui/issues/issue-20605.stderr         |   2 +-
 src/test/ui/issues/issue-21763.stderr         |   4 +-
 src/test/ui/issues/issue-31173.rs             |   2 +-
 src/test/ui/issues/issue-31173.stderr         |  30 +-
 src/test/ui/issues/issue-33941.stderr         |   6 +-
 src/test/ui/issues/issue-34334.stderr         |   6 +-
 src/test/ui/issues/issue-34349.stderr         |  10 +-
 src/test/ui/issues/issue-59488.rs             |   1 +
 src/test/ui/issues/issue-59488.stderr         |  21 +-
 src/test/ui/issues/issue-60218.stderr         |   4 +-
 ...e-66923-show-error-for-correct-call.stderr |  12 +-
 src/test/ui/issues/issue-69455.stderr         |   2 +-
 src/test/ui/iterators/collect-into-array.rs   |   1 +
 .../ui/iterators/collect-into-array.stderr    |   6 +-
 src/test/ui/iterators/collect-into-slice.rs   |   5 +
 .../ui/iterators/collect-into-slice.stderr    |  23 +-
 .../ui/kindck/kindck-impl-type-params-2.rs    |   2 +-
 .../kindck/kindck-impl-type-params-2.stderr   |   2 +-
 .../kindck-inherited-copy-bound.curr.stderr   |   2 +-
 ...copy-bound.object_safe_for_dispatch.stderr |   2 +-
 .../ui/kindck/kindck-nonsendable-1.stderr     |  10 +-
 src/test/ui/kindck/kindck-send-object.stderr  |   8 +-
 src/test/ui/kindck/kindck-send-object1.stderr |   8 +-
 src/test/ui/kindck/kindck-send-object2.stderr |   8 +-
 src/test/ui/kindck/kindck-send-owned.stderr   |   4 +-
 .../branches.stderr                           |   6 +-
 .../recursion4.stderr                         |  12 +-
 .../method-help-unsatisfied-bound.stderr      |   6 +-
 .../defaulted-never-note.fallback.stderr      |   6 +-
 .../ui/never_type/defaulted-never-note.rs     |   1 +
 ...diverging-fallback-no-leak.fallback.stderr |   6 +-
 .../feature-gate-never_type_fallback.stderr   |   8 +-
 ...lue-fallback-issue-66757.nofallback.stderr |   6 +-
 src/test/ui/no-send-res-ports.stderr          |  17 +-
 src/test/ui/not-clone-closure.stderr          |   6 +-
 src/test/ui/not-panic/not-panic-safe-2.stderr |   8 +-
 src/test/ui/not-panic/not-panic-safe-3.stderr |   8 +-
 src/test/ui/not-panic/not-panic-safe-4.stderr |   8 +-
 src/test/ui/not-panic/not-panic-safe-5.stderr |   4 +-
 src/test/ui/not-panic/not-panic-safe-6.stderr |   8 +-
 .../ui/on-unimplemented/multiple-impls.stderr |  12 +-
 src/test/ui/on-unimplemented/on-impl.stderr   |   4 +-
 ...invalid-syntax-in-enum-discriminant.stderr |   4 +-
 .../move-ref-patterns-closure-captures.stderr |  30 +-
 src/test/ui/proc-macro/signature.stderr       |   5 +-
 src/test/ui/range/range-1.stderr              |   2 +-
 .../const-default-method-bodies.stderr        |  10 +-
 .../const-drop-fail.precise.stderr            |   4 +-
 .../const-drop-fail.stock.stderr              |   4 +-
 .../cross-crate.gatednc.stderr                |  10 +-
 .../cross-crate.stocknc.stderr                |  10 +-
 ...-method-body-is-const-same-trait-ck.stderr |  10 +-
 .../trait-where-clause.stderr                 |  12 +-
 src/test/ui/stats/hir-stats.stderr            | 134 ++--
 .../expected-boxed-future-isnt-pinned.stderr  |  12 +-
 ...-trait-object-literal-bound-regions.stderr |   6 +-
 .../imm-ref-trait-object-literal.stderr       |   2 +-
 src/test/ui/suggestions/issue-62843.stderr    |   2 +-
 .../issue-71394-no-from-impl.stderr           |   6 +-
 src/test/ui/suggestions/issue-84973-2.stderr  |   2 +-
 .../suggestions/issue-84973-blacklist.stderr  |   6 +-
 .../suggestions/issue-84973-negative.stderr   |   2 +-
 src/test/ui/suggestions/issue-84973.stderr    |   2 +-
 .../ui/suggestions/slice-issue-87994.stderr   |   8 +-
 ...dding-reference-to-trait-assoc-item.stderr |   4 +-
 .../suggest-borrow-to-dyn-object.stderr       |   4 +-
 ...ggest-imm-mut-trait-implementations.stderr |   6 +-
 .../check-trait-object-bounds-1.stderr        |   4 +-
 .../check-trait-object-bounds-2.stderr        |   4 +-
 .../check-trait-object-bounds-4.stderr        |   4 +-
 .../ui/traits/bad-method-typaram-kind.stderr  |   4 +-
 .../bound/assoc-fn-bound-root-obligation.rs   |   1 -
 .../assoc-fn-bound-root-obligation.stderr     |   6 +-
 .../bound/on-structs-and-enums-locals.rs      |   2 +-
 .../bound/on-structs-and-enums-locals.stderr  |   6 +-
 .../traits/bound/on-structs-and-enums-xc1.rs  |   2 +-
 .../bound/on-structs-and-enums-xc1.stderr     |   6 +-
 .../repeated-supertrait-ambig.stderr          |  30 +-
 src/test/ui/traits/issue-77982.stderr         |   8 +-
 src/test/ui/traits/issue-97576.stderr         |   6 +-
 .../multidispatch-convert-ambig-dest.stderr   |  10 +-
 .../negated-auto-traits-error.stderr          |   2 +-
 .../ui/traits/suggest-where-clause.stderr     |   4 +-
 src/test/ui/transmutability/references.stderr |   4 +-
 .../type-params-in-different-spaces-2.stderr  |  12 +-
 ...ck-default-trait-impl-negation-sync.stderr |   8 +-
 .../ui/ufcs/ufcs-qpath-self-mismatch.stderr   |   6 +-
 ...-infer-fn-once-move-from-projection.stderr |  12 +-
 .../ui/union/union-generic.mirunsafeck.stderr |   4 +-
 .../union/union-generic.thirunsafeck.stderr   |   4 +-
 .../ui/unsized-locals/unsized-exprs.stderr    |   4 +-
 src/test/ui/unsized/issue-30355.stderr        |   4 +-
 src/test/ui/unsized/issue-71659.stderr        |   6 +-
 src/test/ui/unsized/issue-75707.stderr        |   4 +-
 src/test/ui/unsized/unsized-fn-param.stderr   |  16 +-
 src/test/ui/unsized/unsized-struct.stderr     |   4 +-
 src/test/ui/unsized/unsized3.stderr           |  10 +-
 .../where-clause-method-substituion.stderr    |   4 +-
 .../where-clauses-method-unsatisfied.stderr   |   6 +-
 src/tools/rustfmt/src/attr.rs                 |   5 +-
 src/tools/rustfmt/src/imports.rs              |   4 +-
 src/tools/rustfmt/src/modules.rs              |   8 +-
 src/tools/rustfmt/src/parse/parser.rs         |   2 +-
 src/tools/tidy/src/style.rs                   |  15 +-
 291 files changed, 2761 insertions(+), 2103 deletions(-)
 create mode 100644 src/test/assembly/x86_64-floating-point-clamp.rs

diff --git a/.gitignore b/.gitignore
index a6625ac2ac4a1..b16fb6341c2e5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -42,6 +42,7 @@ no_llvm_build
 /llvm/
 /mingw-build/
 /build/
+/build-rust-analyzer/
 /dist/
 /unicode-downloads
 /target
diff --git a/Cargo.lock b/Cargo.lock
index 293fc30903df0..3a35985836c93 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2415,9 +2415,9 @@ dependencies = [
 
 [[package]]
 name = "minifier"
-version = "0.2.1"
+version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ac96d1e7a65f206443f95afff6de8f1690c77c97d6fc9c9bb2d2cd0662e9ff9f"
+checksum = "8eb022374af2f446981254e6bf9efb6e2c9e1a53176d395fca02792fd4435729"
 
 [[package]]
 name = "minimal-lexical"
diff --git a/compiler/rustc_arena/src/lib.rs b/compiler/rustc_arena/src/lib.rs
index 98faacdc1fb59..d2f8ef8eaae7d 100644
--- a/compiler/rustc_arena/src/lib.rs
+++ b/compiler/rustc_arena/src/lib.rs
@@ -219,7 +219,7 @@ impl<T> TypedArena<T> {
             } else {
                 let ptr = self.ptr.get();
                 // Advance the pointer.
-                self.ptr.set(self.ptr.get().offset(1));
+                self.ptr.set(self.ptr.get().add(1));
                 // Write into uninitialized memory.
                 ptr::write(ptr, object);
                 &mut *ptr
diff --git a/compiler/rustc_ast/src/ast.rs b/compiler/rustc_ast/src/ast.rs
index d5180b46aaff4..598bf771008db 100644
--- a/compiler/rustc_ast/src/ast.rs
+++ b/compiler/rustc_ast/src/ast.rs
@@ -504,7 +504,7 @@ pub struct WhereEqPredicate {
 
 #[derive(Clone, Encodable, Decodable, Debug)]
 pub struct Crate {
-    pub attrs: Vec<Attribute>,
+    pub attrs: AttrVec,
     pub items: Vec<P<Item>>,
     pub spans: ModSpans,
     /// Must be equal to `CRATE_NODE_ID` after the crate root is expanded, but may hold
@@ -1268,7 +1268,7 @@ impl Expr {
                 id: DUMMY_NODE_ID,
                 kind: ExprKind::Err,
                 span: DUMMY_SP,
-                attrs: ThinVec::new(),
+                attrs: AttrVec::new(),
                 tokens: None,
             },
         )
@@ -2669,7 +2669,7 @@ impl VariantData {
 /// An item definition.
 #[derive(Clone, Encodable, Decodable, Debug)]
 pub struct Item<K = ItemKind> {
-    pub attrs: Vec<Attribute>,
+    pub attrs: AttrVec,
     pub id: NodeId,
     pub span: Span,
     pub vis: Visibility,
@@ -3036,19 +3036,19 @@ mod size_asserts {
     use super::*;
     use rustc_data_structures::static_assert_size;
     // These are in alphabetical order, which is easy to maintain.
-    static_assert_size!(AssocItem, 120);
+    static_assert_size!(AssocItem, 104);
     static_assert_size!(AssocItemKind, 32);
     static_assert_size!(Attribute, 32);
     static_assert_size!(Block, 48);
     static_assert_size!(Expr, 104);
     static_assert_size!(ExprKind, 72);
     static_assert_size!(Fn, 192);
-    static_assert_size!(ForeignItem, 112);
+    static_assert_size!(ForeignItem, 96);
     static_assert_size!(ForeignItemKind, 24);
     static_assert_size!(GenericBound, 88);
     static_assert_size!(Generics, 72);
     static_assert_size!(Impl, 200);
-    static_assert_size!(Item, 200);
+    static_assert_size!(Item, 184);
     static_assert_size!(ItemKind, 112);
     static_assert_size!(Lit, 48);
     static_assert_size!(LitKind, 24);
diff --git a/compiler/rustc_ast/src/ast_traits.rs b/compiler/rustc_ast/src/ast_traits.rs
index 1fc5e480215ea..0947a71b82432 100644
--- a/compiler/rustc_ast/src/ast_traits.rs
+++ b/compiler/rustc_ast/src/ast_traits.rs
@@ -270,7 +270,7 @@ pub trait HasAttrs {
     /// during token collection.
     const SUPPORTS_CUSTOM_INNER_ATTRS: bool;
     fn attrs(&self) -> &[Attribute];
-    fn visit_attrs(&mut self, f: impl FnOnce(&mut Vec<Attribute>));
+    fn visit_attrs(&mut self, f: impl FnOnce(&mut AttrVec));
 }
 
 macro_rules! impl_has_attrs {
@@ -283,8 +283,8 @@ macro_rules! impl_has_attrs {
                     &self.attrs
                 }
 
-                fn visit_attrs(&mut self, f: impl FnOnce(&mut Vec<Attribute>)) {
-                    VecOrAttrVec::visit(&mut self.attrs, f)
+                fn visit_attrs(&mut self, f: impl FnOnce(&mut AttrVec)) {
+                    f(&mut self.attrs)
                 }
             }
         )+
@@ -299,7 +299,7 @@ macro_rules! impl_has_attrs_none {
                 fn attrs(&self) -> &[Attribute] {
                     &[]
                 }
-                fn visit_attrs(&mut self, _f: impl FnOnce(&mut Vec<Attribute>)) {}
+                fn visit_attrs(&mut self, _f: impl FnOnce(&mut AttrVec)) {}
             }
         )+
     };
@@ -330,7 +330,7 @@ impl<T: AstDeref<Target: HasAttrs>> HasAttrs for T {
     fn attrs(&self) -> &[Attribute] {
         self.ast_deref().attrs()
     }
-    fn visit_attrs(&mut self, f: impl FnOnce(&mut Vec<Attribute>)) {
+    fn visit_attrs(&mut self, f: impl FnOnce(&mut AttrVec)) {
         self.ast_deref_mut().visit_attrs(f)
     }
 }
@@ -340,7 +340,7 @@ impl<T: HasAttrs> HasAttrs for Option<T> {
     fn attrs(&self) -> &[Attribute] {
         self.as_ref().map(|inner| inner.attrs()).unwrap_or(&[])
     }
-    fn visit_attrs(&mut self, f: impl FnOnce(&mut Vec<Attribute>)) {
+    fn visit_attrs(&mut self, f: impl FnOnce(&mut AttrVec)) {
         if let Some(inner) = self.as_mut() {
             inner.visit_attrs(f);
         }
@@ -362,13 +362,13 @@ impl HasAttrs for StmtKind {
         }
     }
 
-    fn visit_attrs(&mut self, f: impl FnOnce(&mut Vec<Attribute>)) {
+    fn visit_attrs(&mut self, f: impl FnOnce(&mut AttrVec)) {
         match self {
-            StmtKind::Local(local) => visit_attrvec(&mut local.attrs, f),
+            StmtKind::Local(local) => f(&mut local.attrs),
             StmtKind::Expr(expr) | StmtKind::Semi(expr) => expr.visit_attrs(f),
             StmtKind::Item(item) => item.visit_attrs(f),
             StmtKind::Empty => {}
-            StmtKind::MacCall(mac) => visit_attrvec(&mut mac.attrs, f),
+            StmtKind::MacCall(mac) => f(&mut mac.attrs),
         }
     }
 }
@@ -378,38 +378,11 @@ impl HasAttrs for Stmt {
     fn attrs(&self) -> &[Attribute] {
         self.kind.attrs()
     }
-    fn visit_attrs(&mut self, f: impl FnOnce(&mut Vec<Attribute>)) {
+    fn visit_attrs(&mut self, f: impl FnOnce(&mut AttrVec)) {
         self.kind.visit_attrs(f);
     }
 }
 
-/// Helper trait for the impls above. Abstracts over
-/// the two types of attribute fields that AST nodes
-/// may have (`Vec<Attribute>` or `AttrVec`).
-trait VecOrAttrVec {
-    fn visit(&mut self, f: impl FnOnce(&mut Vec<Attribute>));
-}
-
-impl VecOrAttrVec for Vec<Attribute> {
-    fn visit(&mut self, f: impl FnOnce(&mut Vec<Attribute>)) {
-        f(self)
-    }
-}
-
-impl VecOrAttrVec for AttrVec {
-    fn visit(&mut self, f: impl FnOnce(&mut Vec<Attribute>)) {
-        visit_attrvec(self, f)
-    }
-}
-
-fn visit_attrvec(attrs: &mut AttrVec, f: impl FnOnce(&mut Vec<Attribute>)) {
-    crate::mut_visit::visit_clobber(attrs, |attrs| {
-        let mut vec = attrs.into();
-        f(&mut vec);
-        vec.into()
-    });
-}
-
 /// A newtype around an AST node that implements the traits above if the node implements them.
 pub struct AstNodeWrapper<Wrapped, Tag> {
     pub wrapped: Wrapped,
diff --git a/compiler/rustc_ast/src/attr/mod.rs b/compiler/rustc_ast/src/attr/mod.rs
index 0d114f1366c4d..5b72ec2b6015c 100644
--- a/compiler/rustc_ast/src/attr/mod.rs
+++ b/compiler/rustc_ast/src/attr/mod.rs
@@ -12,7 +12,6 @@ use crate::tokenstream::{DelimSpan, Spacing, TokenTree};
 use crate::tokenstream::{LazyTokenStream, TokenStream};
 use crate::util::comments;
 
-use rustc_data_structures::thin_vec::ThinVec;
 use rustc_index::bit_set::GrowableBitSet;
 use rustc_span::source_map::BytePos;
 use rustc_span::symbol::{sym, Ident, Symbol};
@@ -487,7 +486,7 @@ impl MetaItemKind {
                     id: ast::DUMMY_NODE_ID,
                     kind: ast::ExprKind::Lit(lit.clone()),
                     span: lit.span,
-                    attrs: ThinVec::new(),
+                    attrs: ast::AttrVec::new(),
                     tokens: None,
                 });
                 MacArgs::Eq(span, MacArgsEq::Ast(expr))
diff --git a/compiler/rustc_ast/src/mut_visit.rs b/compiler/rustc_ast/src/mut_visit.rs
index 0520319e3be14..458d1156ec251 100644
--- a/compiler/rustc_ast/src/mut_visit.rs
+++ b/compiler/rustc_ast/src/mut_visit.rs
@@ -14,7 +14,6 @@ use crate::tokenstream::*;
 
 use rustc_data_structures::map_in_place::MapInPlace;
 use rustc_data_structures::sync::Lrc;
-use rustc_data_structures::thin_vec::ThinVec;
 use rustc_span::source_map::Spanned;
 use rustc_span::symbol::Ident;
 use rustc_span::Span;
@@ -338,12 +337,7 @@ where
 }
 
 // No `noop_` prefix because there isn't a corresponding method in `MutVisitor`.
-pub fn visit_attrs<T: MutVisitor>(attrs: &mut Vec<Attribute>, vis: &mut T) {
-    visit_vec(attrs, |attr| vis.visit_attribute(attr));
-}
-
-// No `noop_` prefix because there isn't a corresponding method in `MutVisitor`.
-pub fn visit_thin_attrs<T: MutVisitor>(attrs: &mut AttrVec, vis: &mut T) {
+pub fn visit_attrs<T: MutVisitor>(attrs: &mut AttrVec, vis: &mut T) {
     for attr in attrs.iter_mut() {
         vis.visit_attribute(attr);
     }
@@ -398,7 +392,7 @@ pub fn noop_flat_map_pat_field<T: MutVisitor>(
     vis.visit_ident(ident);
     vis.visit_pat(pat);
     vis.visit_span(span);
-    visit_thin_attrs(attrs, vis);
+    visit_attrs(attrs, vis);
     smallvec![fp]
 }
 
@@ -424,7 +418,7 @@ pub fn noop_visit_use_tree<T: MutVisitor>(use_tree: &mut UseTree, vis: &mut T) {
 
 pub fn noop_flat_map_arm<T: MutVisitor>(mut arm: Arm, vis: &mut T) -> SmallVec<[Arm; 1]> {
     let Arm { attrs, pat, guard, body, span, id, is_placeholder: _ } = &mut arm;
-    visit_thin_attrs(attrs, vis);
+    visit_attrs(attrs, vis);
     vis.visit_id(id);
     vis.visit_pat(pat);
     visit_opt(guard, |guard| vis.visit_expr(guard));
@@ -507,7 +501,7 @@ pub fn noop_flat_map_variant<T: MutVisitor>(
     let Variant { ident, vis, attrs, id, data, disr_expr, span, is_placeholder: _ } = &mut variant;
     visitor.visit_ident(ident);
     visitor.visit_vis(vis);
-    visit_thin_attrs(attrs, visitor);
+    visit_attrs(attrs, visitor);
     visitor.visit_id(id);
     visitor.visit_variant_data(data);
     visit_opt(disr_expr, |disr_expr| visitor.visit_anon_const(disr_expr));
@@ -589,7 +583,7 @@ pub fn noop_visit_local<T: MutVisitor>(local: &mut P<Local>, vis: &mut T) {
         }
     }
     vis.visit_span(span);
-    visit_thin_attrs(attrs, vis);
+    visit_attrs(attrs, vis);
     visit_lazy_tts(tokens, vis);
 }
 
@@ -640,7 +634,7 @@ pub fn noop_visit_meta_item<T: MutVisitor>(mi: &mut MetaItem, vis: &mut T) {
 pub fn noop_flat_map_param<T: MutVisitor>(mut param: Param, vis: &mut T) -> SmallVec<[Param; 1]> {
     let Param { attrs, id, pat, span, ty, is_placeholder: _ } = &mut param;
     vis.visit_id(id);
-    visit_thin_attrs(attrs, vis);
+    visit_attrs(attrs, vis);
     vis.visit_pat(pat);
     vis.visit_span(span);
     vis.visit_ty(ty);
@@ -882,7 +876,7 @@ pub fn noop_flat_map_generic_param<T: MutVisitor>(
     if let Some(ref mut colon_span) = colon_span {
         vis.visit_span(colon_span);
     }
-    visit_thin_attrs(attrs, vis);
+    visit_attrs(attrs, vis);
     visit_vec(bounds, |bound| noop_visit_param_bound(bound, vis));
     match kind {
         GenericParamKind::Lifetime => {}
@@ -978,7 +972,7 @@ pub fn noop_flat_map_field_def<T: MutVisitor>(
     visitor.visit_vis(vis);
     visitor.visit_id(id);
     visitor.visit_ty(ty);
-    visit_thin_attrs(attrs, visitor);
+    visit_attrs(attrs, visitor);
     smallvec![fd]
 }
 
@@ -991,7 +985,7 @@ pub fn noop_flat_map_expr_field<T: MutVisitor>(
     vis.visit_expr(expr);
     vis.visit_id(id);
     vis.visit_span(span);
-    visit_thin_attrs(attrs, vis);
+    visit_attrs(attrs, vis);
     smallvec![f]
 }
 
@@ -1432,7 +1426,7 @@ pub fn noop_visit_expr<T: MutVisitor>(
     }
     vis.visit_id(id);
     vis.visit_span(span);
-    visit_thin_attrs(attrs, vis);
+    visit_attrs(attrs, vis);
     visit_lazy_tts(tokens, vis);
 }
 
@@ -1478,7 +1472,7 @@ pub fn noop_flat_map_stmt_kind<T: MutVisitor>(
         StmtKind::MacCall(mut mac) => {
             let MacCallStmt { mac: mac_, style: _, attrs, tokens } = mac.deref_mut();
             vis.visit_mac_call(mac_);
-            visit_thin_attrs(attrs, vis);
+            visit_attrs(attrs, vis);
             visit_lazy_tts(tokens, vis);
             smallvec![StmtKind::MacCall(mac)]
         }
@@ -1513,12 +1507,6 @@ impl<T: DummyAstNode + 'static> DummyAstNode for P<T> {
     }
 }
 
-impl<T> DummyAstNode for ThinVec<T> {
-    fn dummy() -> Self {
-        Default::default()
-    }
-}
-
 impl DummyAstNode for Item {
     fn dummy() -> Self {
         Item {
diff --git a/compiler/rustc_ast_lowering/src/expr.rs b/compiler/rustc_ast_lowering/src/expr.rs
index 32dbd2ff47d6b..bd61f4fa87ab8 100644
--- a/compiler/rustc_ast_lowering/src/expr.rs
+++ b/compiler/rustc_ast_lowering/src/expr.rs
@@ -6,7 +6,6 @@ use rustc_ast::attr;
 use rustc_ast::ptr::P as AstP;
 use rustc_ast::*;
 use rustc_data_structures::stack::ensure_sufficient_stack;
-use rustc_data_structures::thin_vec::ThinVec;
 use rustc_errors::struct_span_err;
 use rustc_hir as hir;
 use rustc_hir::def::Res;
@@ -448,12 +447,12 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let lowered_cond = self.with_loop_condition_scope(|t| t.lower_expr(cond));
         let new_cond = self.manage_let_cond(lowered_cond);
         let then = self.lower_block_expr(body);
-        let expr_break = self.expr_break(span, ThinVec::new());
+        let expr_break = self.expr_break(span, AttrVec::new());
         let stmt_break = self.stmt_expr(span, expr_break);
         let else_blk = self.block_all(span, arena_vec![self; stmt_break], None);
-        let else_expr = self.arena.alloc(self.expr_block(else_blk, ThinVec::new()));
+        let else_expr = self.arena.alloc(self.expr_block(else_blk, AttrVec::new()));
         let if_kind = hir::ExprKind::If(new_cond, self.arena.alloc(then), Some(else_expr));
-        let if_expr = self.expr(span, if_kind, ThinVec::new());
+        let if_expr = self.expr(span, if_kind, AttrVec::new());
         let block = self.block_expr(self.arena.alloc(if_expr));
         let span = self.lower_span(span.with_hi(cond.span.hi()));
         let opt_label = self.lower_label(opt_label);
@@ -512,7 +511,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let constructor = self.arena.alloc(self.expr_lang_item_path(
             method_span,
             lang_item,
-            ThinVec::new(),
+            AttrVec::new(),
             None,
         ));
         self.expr_call(overall_span, constructor, std::slice::from_ref(expr))
@@ -635,7 +634,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let gen_future = self.expr_lang_item_path(
             unstable_span,
             hir::LangItem::FromGenerator,
-            ThinVec::new(),
+            AttrVec::new(),
             None,
         );
 
@@ -747,7 +746,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             let break_x = self.with_loop_scope(loop_node_id, move |this| {
                 let expr_break =
                     hir::ExprKind::Break(this.lower_loop_destination(None), Some(x_expr));
-                this.arena.alloc(this.expr(gen_future_span, expr_break, ThinVec::new()))
+                this.arena.alloc(this.expr(gen_future_span, expr_break, AttrVec::new()))
             });
             self.arm(ready_pat, break_x)
         };
@@ -780,7 +779,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             let yield_expr = self.expr(
                 span,
                 hir::ExprKind::Yield(unit, hir::YieldSource::Await { expr: Some(expr_hir_id) }),
-                ThinVec::new(),
+                AttrVec::new(),
             );
             let yield_expr = self.arena.alloc(yield_expr);
 
@@ -987,7 +986,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                     hir::AsyncGeneratorKind::Closure,
                     |this| this.with_new_scopes(|this| this.lower_expr_mut(body)),
                 );
-                this.expr(fn_decl_span, async_body, ThinVec::new())
+                this.expr(fn_decl_span, async_body, AttrVec::new())
             });
             body_id
         });
@@ -1257,7 +1256,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let ident = self.expr_ident(lhs.span, ident, binding);
         let assign =
             hir::ExprKind::Assign(self.lower_expr(lhs), ident, self.lower_span(eq_sign_span));
-        let expr = self.expr(lhs.span, assign, ThinVec::new());
+        let expr = self.expr(lhs.span, assign, AttrVec::new());
         assignments.push(self.stmt_expr(lhs.span, expr));
         pat
     }
@@ -1299,7 +1298,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let fn_path =
             hir::QPath::LangItem(hir::LangItem::RangeInclusiveNew, self.lower_span(span), None);
         let fn_expr =
-            self.arena.alloc(self.expr(span, hir::ExprKind::Path(fn_path), ThinVec::new()));
+            self.arena.alloc(self.expr(span, hir::ExprKind::Path(fn_path), AttrVec::new()));
         hir::ExprKind::Call(fn_expr, arena_vec![self; e1, e2])
     }
 
@@ -1472,7 +1471,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         // `None => break`
         let none_arm = {
             let break_expr =
-                self.with_loop_scope(e.id, |this| this.expr_break_alloc(for_span, ThinVec::new()));
+                self.with_loop_scope(e.id, |this| this.expr_break_alloc(for_span, AttrVec::new()));
             let pat = self.pat_none(for_span);
             self.arm(pat, break_expr)
         };
@@ -1481,7 +1480,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let some_arm = {
             let some_pat = self.pat_some(pat_span, pat);
             let body_block = self.with_loop_scope(e.id, |this| this.lower_block(body, false));
-            let body_expr = self.arena.alloc(self.expr_block(body_block, ThinVec::new()));
+            let body_expr = self.arena.alloc(self.expr_block(body_block, AttrVec::new()));
             self.arm(some_pat, body_expr)
         };
 
@@ -1596,7 +1595,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             };
             attr::mk_attr_outer(allow)
         };
-        let attrs = vec![attr];
+        let attrs: AttrVec = vec![attr].into();
 
         // `ControlFlow::Continue(val) => #[allow(unreachable_code)] val,`
         let continue_arm = {
@@ -1606,7 +1605,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 span,
                 val_ident,
                 val_pat_nid,
-                ThinVec::from(attrs.clone()),
+                attrs.clone(),
             ));
             let continue_pat = self.pat_cf_continue(unstable_span, val_pat);
             self.arm(continue_pat, val_expr)
@@ -1625,7 +1624,6 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 self.arena.alloc(residual_expr),
                 unstable_span,
             );
-            let thin_attrs = ThinVec::from(attrs);
             let ret_expr = if let Some(catch_node) = self.catch_scope {
                 let target_id = Ok(self.lower_node_id(catch_node));
                 self.arena.alloc(self.expr(
@@ -1634,13 +1632,13 @@ impl<'hir> LoweringContext<'_, 'hir> {
                         hir::Destination { label: None, target_id },
                         Some(from_residual_expr),
                     ),
-                    thin_attrs,
+                    attrs,
                 ))
             } else {
                 self.arena.alloc(self.expr(
                     try_span,
                     hir::ExprKind::Ret(Some(from_residual_expr)),
-                    thin_attrs,
+                    attrs,
                 ))
             };
 
@@ -1728,7 +1726,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         arms: &'hir [hir::Arm<'hir>],
         source: hir::MatchSource,
     ) -> hir::Expr<'hir> {
-        self.expr(span, hir::ExprKind::Match(arg, arms, source), ThinVec::new())
+        self.expr(span, hir::ExprKind::Match(arg, arms, source), AttrVec::new())
     }
 
     fn expr_break(&mut self, span: Span, attrs: AttrVec) -> hir::Expr<'hir> {
@@ -1745,12 +1743,12 @@ impl<'hir> LoweringContext<'_, 'hir> {
         self.expr(
             span,
             hir::ExprKind::AddrOf(hir::BorrowKind::Ref, hir::Mutability::Mut, e),
-            ThinVec::new(),
+            AttrVec::new(),
         )
     }
 
     fn expr_unit(&mut self, sp: Span) -> &'hir hir::Expr<'hir> {
-        self.arena.alloc(self.expr(sp, hir::ExprKind::Tup(&[]), ThinVec::new()))
+        self.arena.alloc(self.expr(sp, hir::ExprKind::Tup(&[]), AttrVec::new()))
     }
 
     fn expr_call_mut(
@@ -1759,7 +1757,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         e: &'hir hir::Expr<'hir>,
         args: &'hir [hir::Expr<'hir>],
     ) -> hir::Expr<'hir> {
-        self.expr(span, hir::ExprKind::Call(e, args), ThinVec::new())
+        self.expr(span, hir::ExprKind::Call(e, args), AttrVec::new())
     }
 
     fn expr_call(
@@ -1779,7 +1777,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         hir_id: Option<hir::HirId>,
     ) -> hir::Expr<'hir> {
         let path =
-            self.arena.alloc(self.expr_lang_item_path(span, lang_item, ThinVec::new(), hir_id));
+            self.arena.alloc(self.expr_lang_item_path(span, lang_item, AttrVec::new(), hir_id));
         self.expr_call_mut(span, path, args)
     }
 
@@ -1822,7 +1820,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         ident: Ident,
         binding: hir::HirId,
     ) -> hir::Expr<'hir> {
-        self.expr_ident_with_attrs(sp, ident, binding, ThinVec::new())
+        self.expr_ident_with_attrs(sp, ident, binding, AttrVec::new())
     }
 
     fn expr_ident_with_attrs(
@@ -1860,13 +1858,13 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 }),
                 None,
             ),
-            ThinVec::new(),
+            AttrVec::new(),
         )
     }
 
     fn expr_block_empty(&mut self, span: Span) -> &'hir hir::Expr<'hir> {
         let blk = self.block_all(span, &[], None);
-        let expr = self.expr_block(blk, ThinVec::new());
+        let expr = self.expr_block(blk, AttrVec::new());
         self.arena.alloc(expr)
     }
 
diff --git a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
index d28187dc42de4..6894ec7956cfe 100644
--- a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
@@ -854,7 +854,6 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                     ident.span,
                     "calling this method introduces the `impl`'s 'static` requirement",
                 );
-                // TODO!
                 err.span_note(multi_span, "the used `impl` has a `'static` requirement");
                 err.span_suggestion_verbose(
                     span.shrink_to_hi(),
diff --git a/compiler/rustc_borrowck/src/lib.rs b/compiler/rustc_borrowck/src/lib.rs
index 2828b972c5f99..78c817150a65a 100644
--- a/compiler/rustc_borrowck/src/lib.rs
+++ b/compiler/rustc_borrowck/src/lib.rs
@@ -50,6 +50,8 @@ use rustc_mir_dataflow::move_paths::{InitLocation, LookupResult, MoveData, MoveE
 use rustc_mir_dataflow::Analysis;
 use rustc_mir_dataflow::MoveDataParamEnv;
 
+use crate::session_diagnostics::VarNeedNotMut;
+
 use self::diagnostics::{AccessKind, RegionName};
 use self::location::LocationTable;
 use self::prefixes::PrefixSet;
@@ -424,12 +426,7 @@ fn do_mir_borrowck<'a, 'tcx>(
             continue;
         }
 
-        tcx.emit_spanned_lint(
-            UNUSED_MUT,
-            lint_root,
-            span,
-            session_diagnostics::VarBetterNotMut { span },
-        )
+        tcx.emit_spanned_lint(UNUSED_MUT, lint_root, span, VarNeedNotMut { span })
     }
 
     let tainted_by_errors = mbcx.emit_errors();
diff --git a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs
index b0d7253651b09..127cb4e408372 100644
--- a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs
+++ b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs
@@ -641,7 +641,6 @@ impl<'tcx> TypeFolder<'tcx> for ReverseMapper<'tcx> {
                     Some(GenericArgKind::Const(c1)) => c1,
                     Some(u) => panic!("const mapped to unexpected kind: {:?}", u),
                     None => {
-                        //FIXME!
                         self.tcx.sess.emit_err(ConstNotUsedTraitAlias {
                             ct: ct.to_string(),
                             span: self.span,
diff --git a/compiler/rustc_borrowck/src/session_diagnostics.rs b/compiler/rustc_borrowck/src/session_diagnostics.rs
index 3a24b28da3556..ff2196760039c 100644
--- a/compiler/rustc_borrowck/src/session_diagnostics.rs
+++ b/compiler/rustc_borrowck/src/session_diagnostics.rs
@@ -1,18 +1,9 @@
-use rustc_errors::MultiSpan;
 use rustc_macros::{LintDiagnostic, SessionDiagnostic, SessionSubdiagnostic};
 use rustc_middle::ty::Ty;
 use rustc_span::Span;
 
 #[derive(SessionDiagnostic)]
-#[error(borrowck::move_borrowed, code = "E0505")]
-pub(crate) struct MoveBorrowed<'cx> {
-    #[primary_span]
-    pub span: Span,
-    pub desc: &'cx str,
-}
-
-#[derive(SessionDiagnostic)]
-#[error(borrowck::move_unsized, code = "E0161")]
+#[diag(borrowck::move_unsized, code = "E0161")]
 pub(crate) struct MoveUnsized<'tcx> {
     pub ty: Ty<'tcx>,
     #[primary_span]
@@ -21,7 +12,7 @@ pub(crate) struct MoveUnsized<'tcx> {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(borrowck::higher_ranked_lifetime_error)]
+#[diag(borrowck::higher_ranked_lifetime_error)]
 pub(crate) struct HigherRankedLifetimeError {
     #[subdiagnostic]
     pub cause: Option<HigherRankedErrorCause>,
@@ -38,14 +29,14 @@ pub(crate) enum HigherRankedErrorCause {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(borrowck::higher_ranked_subtype_error)]
+#[diag(borrowck::higher_ranked_subtype_error)]
 pub(crate) struct HigherRankedSubtypeError {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(borrowck::generic_does_not_live_long_enough)]
+#[diag(borrowck::generic_does_not_live_long_enough)]
 pub(crate) struct GenericDoesNotLiveLongEnough {
     pub kind: String,
     #[primary_span]
@@ -53,14 +44,14 @@ pub(crate) struct GenericDoesNotLiveLongEnough {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(borrowck::var_better_not_mut)]
-pub(crate) struct VarBetterNotMut {
+#[diag(borrowck::var_does_not_need_mut)]
+pub(crate) struct VarNeedNotMut {
     #[suggestion_short(applicability = "machine-applicable", code = "")]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(borrowck::const_not_used_in_type_alias)]
+#[diag(borrowck::const_not_used_in_type_alias)]
 pub(crate) struct ConstNotUsedTraitAlias {
     pub ct: String,
     #[primary_span]
@@ -68,7 +59,7 @@ pub(crate) struct ConstNotUsedTraitAlias {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(borrowck::var_cannot_escape_closure)]
+#[diag(borrowck::var_cannot_escape_closure)]
 #[note]
 #[note(borrowck::cannot_escape)]
 pub(crate) struct FnMutError {
@@ -104,7 +95,7 @@ pub(crate) enum FnMutReturnTypeErr {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(borrowck::lifetime_constraints_error)]
+#[diag(borrowck::lifetime_constraints_error)]
 pub(crate) struct LifeTimeOutLiveErr {
     #[primary_span]
     pub span: Span,
@@ -131,12 +122,3 @@ pub(crate) enum LifeTimeReturnCategoryErr {
         outlived_fr_name: String,
     },
 }
-
-#[derive(SessionSubdiagnostic)]
-pub(crate) enum StaticLifeTimeRequireErr {
-    #[note(borrowck::impl_require_static)]
-    UsedImpl {
-        #[primary_span]
-        span: MultiSpan,
-    },
-}
diff --git a/compiler/rustc_borrowck/src/type_check/canonical.rs b/compiler/rustc_borrowck/src/type_check/canonical.rs
index 6cfe5efb68886..451b82c5c1870 100644
--- a/compiler/rustc_borrowck/src/type_check/canonical.rs
+++ b/compiler/rustc_borrowck/src/type_check/canonical.rs
@@ -90,12 +90,13 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         locations: Locations,
         category: ConstraintCategory<'tcx>,
     ) {
-        self.prove_predicates(
-            Some(ty::Binder::dummy(ty::PredicateKind::Trait(ty::TraitPredicate {
+        self.prove_predicate(
+            ty::Binder::dummy(ty::PredicateKind::Trait(ty::TraitPredicate {
                 trait_ref,
                 constness: ty::BoundConstness::NotConst,
                 polarity: ty::ImplPolarity::Positive,
-            }))),
+            }))
+            .to_predicate(self.tcx()),
             locations,
             category,
         );
diff --git a/compiler/rustc_borrowck/src/type_check/free_region_relations.rs b/compiler/rustc_borrowck/src/type_check/free_region_relations.rs
index 74655369faf03..bb28622edf931 100644
--- a/compiler/rustc_borrowck/src/type_check/free_region_relations.rs
+++ b/compiler/rustc_borrowck/src/type_check/free_region_relations.rs
@@ -268,7 +268,7 @@ impl<'tcx> UniversalRegionRelationsBuilder<'_, 'tcx> {
                 // }
                 // impl Foo for () {
                 //   type Bar = ();
-                //   fn foo(&self) ->&() {}
+                //   fn foo(&self) -> &() {}
                 // }
                 // ```
                 // Both &Self::Bar and &() are WF
diff --git a/compiler/rustc_borrowck/src/type_check/mod.rs b/compiler/rustc_borrowck/src/type_check/mod.rs
index 7bf7f7357bf4f..293d847ec9ab7 100644
--- a/compiler/rustc_borrowck/src/type_check/mod.rs
+++ b/compiler/rustc_borrowck/src/type_check/mod.rs
@@ -178,97 +178,15 @@ pub(crate) fn type_check<'mir, 'tcx>(
         upvars,
     };
 
-    let opaque_type_values = type_check_internal(
+    let mut checker = TypeChecker::new(
         infcx,
-        param_env,
         body,
-        promoted,
+        param_env,
         &region_bound_pairs,
         implicit_region_bound,
         &mut borrowck_context,
-        |mut cx| {
-            debug!("inside extra closure of type_check_internal");
-            cx.equate_inputs_and_outputs(&body, universal_regions, &normalized_inputs_and_output);
-            liveness::generate(
-                &mut cx,
-                body,
-                elements,
-                flow_inits,
-                move_data,
-                location_table,
-                use_polonius,
-            );
-
-            translate_outlives_facts(&mut cx);
-            let opaque_type_values =
-                infcx.inner.borrow_mut().opaque_type_storage.take_opaque_types();
-
-            opaque_type_values
-                .into_iter()
-                .map(|(opaque_type_key, decl)| {
-                    cx.fully_perform_op(
-                        Locations::All(body.span),
-                        ConstraintCategory::OpaqueType,
-                        CustomTypeOp::new(
-                            |infcx| {
-                                infcx.register_member_constraints(
-                                    param_env,
-                                    opaque_type_key,
-                                    decl.hidden_type.ty,
-                                    decl.hidden_type.span,
-                                );
-                                Ok(InferOk { value: (), obligations: vec![] })
-                            },
-                            || "opaque_type_map".to_string(),
-                        ),
-                    )
-                    .unwrap();
-                    let mut hidden_type = infcx.resolve_vars_if_possible(decl.hidden_type);
-                    trace!(
-                        "finalized opaque type {:?} to {:#?}",
-                        opaque_type_key,
-                        hidden_type.ty.kind()
-                    );
-                    if hidden_type.has_infer_types_or_consts() {
-                        infcx.tcx.sess.delay_span_bug(
-                            decl.hidden_type.span,
-                            &format!("could not resolve {:#?}", hidden_type.ty.kind()),
-                        );
-                        hidden_type.ty = infcx.tcx.ty_error();
-                    }
-
-                    (opaque_type_key, (hidden_type, decl.origin))
-                })
-                .collect()
-        },
     );
 
-    MirTypeckResults { constraints, universal_region_relations, opaque_type_values }
-}
-
-#[instrument(
-    skip(infcx, body, promoted, region_bound_pairs, borrowck_context, extra),
-    level = "debug"
-)]
-fn type_check_internal<'a, 'tcx, R>(
-    infcx: &'a InferCtxt<'a, 'tcx>,
-    param_env: ty::ParamEnv<'tcx>,
-    body: &'a Body<'tcx>,
-    promoted: &'a IndexVec<Promoted, Body<'tcx>>,
-    region_bound_pairs: &'a RegionBoundPairs<'tcx>,
-    implicit_region_bound: ty::Region<'tcx>,
-    borrowck_context: &'a mut BorrowCheckContext<'a, 'tcx>,
-    extra: impl FnOnce(TypeChecker<'a, 'tcx>) -> R,
-) -> R {
-    debug!("body: {:#?}", body);
-    let mut checker = TypeChecker::new(
-        infcx,
-        body,
-        param_env,
-        region_bound_pairs,
-        implicit_region_bound,
-        borrowck_context,
-    );
     let errors_reported = {
         let mut verifier = TypeVerifier::new(&mut checker, promoted);
         verifier.visit_body(&body);
@@ -280,7 +198,56 @@ fn type_check_internal<'a, 'tcx, R>(
         checker.typeck_mir(body);
     }
 
-    extra(checker)
+    checker.equate_inputs_and_outputs(&body, universal_regions, &normalized_inputs_and_output);
+    liveness::generate(
+        &mut checker,
+        body,
+        elements,
+        flow_inits,
+        move_data,
+        location_table,
+        use_polonius,
+    );
+
+    translate_outlives_facts(&mut checker);
+    let opaque_type_values = infcx.inner.borrow_mut().opaque_type_storage.take_opaque_types();
+
+    let opaque_type_values = opaque_type_values
+        .into_iter()
+        .map(|(opaque_type_key, decl)| {
+            checker
+                .fully_perform_op(
+                    Locations::All(body.span),
+                    ConstraintCategory::OpaqueType,
+                    CustomTypeOp::new(
+                        |infcx| {
+                            infcx.register_member_constraints(
+                                param_env,
+                                opaque_type_key,
+                                decl.hidden_type.ty,
+                                decl.hidden_type.span,
+                            );
+                            Ok(InferOk { value: (), obligations: vec![] })
+                        },
+                        || "opaque_type_map".to_string(),
+                    ),
+                )
+                .unwrap();
+            let mut hidden_type = infcx.resolve_vars_if_possible(decl.hidden_type);
+            trace!("finalized opaque type {:?} to {:#?}", opaque_type_key, hidden_type.ty.kind());
+            if hidden_type.has_infer_types_or_consts() {
+                infcx.tcx.sess.delay_span_bug(
+                    decl.hidden_type.span,
+                    &format!("could not resolve {:#?}", hidden_type.ty.kind()),
+                );
+                hidden_type.ty = infcx.tcx.ty_error();
+            }
+
+            (opaque_type_key, (hidden_type, decl.origin))
+        })
+        .collect();
+
+    MirTypeckResults { constraints, universal_region_relations, opaque_type_values }
 }
 
 fn translate_outlives_facts(typeck: &mut TypeChecker<'_, '_>) {
@@ -1911,7 +1878,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 }
             }
 
-            &Rvalue::NullaryOp(_, ty) => {
+            &Rvalue::NullaryOp(NullOp::SizeOf | NullOp::AlignOf, ty) => {
                 let trait_ref = ty::TraitRef {
                     def_id: tcx.require_lang_item(LangItem::Sized, Some(self.last_span)),
                     substs: tcx.mk_substs_trait(ty, &[]),
diff --git a/compiler/rustc_builtin_macros/src/asm.rs b/compiler/rustc_builtin_macros/src/asm.rs
index 1a0ea8f416064..a1051d990b14b 100644
--- a/compiler/rustc_builtin_macros/src/asm.rs
+++ b/compiler/rustc_builtin_macros/src/asm.rs
@@ -852,7 +852,7 @@ pub(super) fn expand_global_asm<'cx>(
             if let Some(inline_asm) = expand_preparsed_asm(ecx, args) {
                 MacEager::items(smallvec![P(ast::Item {
                     ident: Ident::empty(),
-                    attrs: Vec::new(),
+                    attrs: ast::AttrVec::new(),
                     id: ast::DUMMY_NODE_ID,
                     kind: ast::ItemKind::GlobalAsm(Box::new(inline_asm)),
                     vis: ast::Visibility {
diff --git a/compiler/rustc_builtin_macros/src/assert/context.rs b/compiler/rustc_builtin_macros/src/assert/context.rs
index d30fd479015ff..d2ee4249989ee 100644
--- a/compiler/rustc_builtin_macros/src/assert/context.rs
+++ b/compiler/rustc_builtin_macros/src/assert/context.rs
@@ -119,7 +119,8 @@ impl<'cx, 'a> Context<'cx, 'a> {
                 vec![self.cx.attribute(attr::mk_list_item(
                     Ident::new(sym::allow, self.span),
                     vec![attr::mk_nested_word_item(Ident::new(sym::unused_imports, self.span))],
-                ))],
+                ))]
+                .into(),
                 ItemKind::Use(UseTree {
                     prefix: self.cx.path(self.span, self.cx.std_path(&[sym::asserting])),
                     kind: UseTreeKind::Nested(vec![
diff --git a/compiler/rustc_builtin_macros/src/cfg.rs b/compiler/rustc_builtin_macros/src/cfg.rs
index aa355150b4f81..9046bf1305933 100644
--- a/compiler/rustc_builtin_macros/src/cfg.rs
+++ b/compiler/rustc_builtin_macros/src/cfg.rs
@@ -36,7 +36,7 @@ pub fn expand_cfg(
 }
 
 #[derive(SessionDiagnostic)]
-#[error(builtin_macros::requires_cfg_pattern)]
+#[diag(builtin_macros::requires_cfg_pattern)]
 struct RequiresCfgPattern {
     #[primary_span]
     #[label]
@@ -44,7 +44,7 @@ struct RequiresCfgPattern {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(builtin_macros::expected_one_cfg_pattern)]
+#[diag(builtin_macros::expected_one_cfg_pattern)]
 struct OneCfgPattern {
     #[primary_span]
     span: Span,
diff --git a/compiler/rustc_builtin_macros/src/deriving/clone.rs b/compiler/rustc_builtin_macros/src/deriving/clone.rs
index ee4c5aea1a352..dd7989cf48c37 100644
--- a/compiler/rustc_builtin_macros/src/deriving/clone.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/clone.rs
@@ -68,7 +68,7 @@ pub fn expand_deriving_clone(
     }
 
     let inline = cx.meta_word(span, sym::inline);
-    let attrs = vec![cx.attribute(inline)];
+    let attrs = vec![cx.attribute(inline)].into();
     let trait_def = TraitDef {
         span,
         path: path_std!(clone::Clone),
diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs b/compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs
index f99ee8cb2d53c..9b6d3e5032f94 100644
--- a/compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs
@@ -20,7 +20,7 @@ pub fn expand_deriving_eq(
     let hidden = rustc_ast::attr::mk_nested_word_item(Ident::new(sym::hidden, span));
     let doc = rustc_ast::attr::mk_list_item(Ident::new(sym::doc, span), vec![hidden]);
     let no_coverage = cx.meta_word(span, sym::no_coverage);
-    let attrs = vec![cx.attribute(inline), cx.attribute(doc), cx.attribute(no_coverage)];
+    let attrs = vec![cx.attribute(inline), cx.attribute(doc), cx.attribute(no_coverage)].into();
     let trait_def = TraitDef {
         span,
         path: path_std!(cmp::Eq),
diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/ord.rs b/compiler/rustc_builtin_macros/src/deriving/cmp/ord.rs
index 8aa16dfeb0f1f..0e17b95178759 100644
--- a/compiler/rustc_builtin_macros/src/deriving/cmp/ord.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/cmp/ord.rs
@@ -15,7 +15,7 @@ pub fn expand_deriving_ord(
     push: &mut dyn FnMut(Annotatable),
 ) {
     let inline = cx.meta_word(span, sym::inline);
-    let attrs = vec![cx.attribute(inline)];
+    let attrs = vec![cx.attribute(inline)].into();
     let trait_def = TraitDef {
         span,
         path: path_std!(cmp::Ord),
diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs b/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs
index 6f86092ba491b..ac1325b92a6f3 100644
--- a/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs
@@ -68,7 +68,7 @@ pub fn expand_deriving_partial_eq(
     // No need to generate `ne`, the default suffices, and not generating it is
     // faster.
     let inline = cx.meta_word(span, sym::inline);
-    let attrs = vec![cx.attribute(inline)];
+    let attrs = vec![cx.attribute(inline)].into();
     let methods = vec![MethodDef {
         name: sym::eq,
         generics: Bounds::empty(),
diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/partial_ord.rs b/compiler/rustc_builtin_macros/src/deriving/cmp/partial_ord.rs
index 137c779f81b84..7763e55401783 100644
--- a/compiler/rustc_builtin_macros/src/deriving/cmp/partial_ord.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/cmp/partial_ord.rs
@@ -19,7 +19,7 @@ pub fn expand_deriving_partial_ord(
         Path(Path::new_(pathvec_std!(option::Option), vec![Box::new(ordering_ty)], PathKind::Std));
 
     let inline = cx.meta_word(span, sym::inline);
-    let attrs = vec![cx.attribute(inline)];
+    let attrs = vec![cx.attribute(inline)].into();
 
     let partial_cmp_def = MethodDef {
         name: sym::partial_cmp,
diff --git a/compiler/rustc_builtin_macros/src/deriving/debug.rs b/compiler/rustc_builtin_macros/src/deriving/debug.rs
index f82175af4f6f2..4af7fd8165388 100644
--- a/compiler/rustc_builtin_macros/src/deriving/debug.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/debug.rs
@@ -29,7 +29,7 @@ pub fn expand_deriving_debug(
             explicit_self: true,
             nonself_args: vec![(fmtr, sym::f)],
             ret_ty: Path(path_std!(fmt::Result)),
-            attributes: Vec::new(),
+            attributes: ast::AttrVec::new(),
             unify_fieldless_variants: false,
             combine_substructure: combine_substructure(Box::new(|a, b, c| {
                 show_substructure(a, b, c)
diff --git a/compiler/rustc_builtin_macros/src/deriving/decodable.rs b/compiler/rustc_builtin_macros/src/deriving/decodable.rs
index 47da0862b52fc..7174dbbe7ea8b 100644
--- a/compiler/rustc_builtin_macros/src/deriving/decodable.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/decodable.rs
@@ -47,7 +47,7 @@ pub fn expand_deriving_rustc_decodable(
                 ],
                 PathKind::Std,
             )),
-            attributes: Vec::new(),
+            attributes: ast::AttrVec::new(),
             unify_fieldless_variants: false,
             combine_substructure: combine_substructure(Box::new(|a, b, c| {
                 decodable_substructure(a, b, c, krate)
diff --git a/compiler/rustc_builtin_macros/src/deriving/default.rs b/compiler/rustc_builtin_macros/src/deriving/default.rs
index a431832080c0c..f316f01ef6615 100644
--- a/compiler/rustc_builtin_macros/src/deriving/default.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/default.rs
@@ -2,9 +2,7 @@ use crate::deriving::generic::ty::*;
 use crate::deriving::generic::*;
 
 use rustc_ast as ast;
-use rustc_ast::walk_list;
-use rustc_ast::EnumDef;
-use rustc_ast::VariantData;
+use rustc_ast::{walk_list, EnumDef, VariantData};
 use rustc_errors::Applicability;
 use rustc_expand::base::{Annotatable, DummyResult, ExtCtxt};
 use rustc_span::symbol::Ident;
@@ -22,7 +20,7 @@ pub fn expand_deriving_default(
     item.visit_with(&mut DetectNonVariantDefaultAttr { cx });
 
     let inline = cx.meta_word(span, sym::inline);
-    let attrs = vec![cx.attribute(inline)];
+    let attrs = vec![cx.attribute(inline)].into();
     let trait_def = TraitDef {
         span,
         path: Path::new(vec![kw::Default, sym::Default]),
diff --git a/compiler/rustc_builtin_macros/src/deriving/encodable.rs b/compiler/rustc_builtin_macros/src/deriving/encodable.rs
index d43c66a5fa644..b220e54238f46 100644
--- a/compiler/rustc_builtin_macros/src/deriving/encodable.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/encodable.rs
@@ -89,7 +89,7 @@ use crate::deriving::generic::ty::*;
 use crate::deriving::generic::*;
 use crate::deriving::pathvec_std;
 
-use rustc_ast::{ExprKind, MetaItem, Mutability};
+use rustc_ast::{AttrVec, ExprKind, MetaItem, Mutability};
 use rustc_expand::base::{Annotatable, ExtCtxt};
 use rustc_span::symbol::{sym, Ident, Symbol};
 use rustc_span::Span;
@@ -131,7 +131,7 @@ pub fn expand_deriving_rustc_encodable(
                 ],
                 PathKind::Std,
             )),
-            attributes: Vec::new(),
+            attributes: AttrVec::new(),
             unify_fieldless_variants: false,
             combine_substructure: combine_substructure(Box::new(|a, b, c| {
                 encodable_substructure(a, b, c, krate)
diff --git a/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs b/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs
index a39b97d07ef0a..c1bbc601560fa 100644
--- a/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs
@@ -217,7 +217,7 @@ pub struct MethodDef<'a> {
     /// Returns type
     pub ret_ty: Ty,
 
-    pub attributes: Vec<ast::Attribute>,
+    pub attributes: ast::AttrVec,
 
     /// Can we combine fieldless variants for enums into a single match arm?
     /// If true, indicates that the trait operation uses the enum tag in some
@@ -562,7 +562,7 @@ impl<'a> TraitDef<'a> {
                     kind: ast::VisibilityKind::Inherited,
                     tokens: None,
                 },
-                attrs: Vec::new(),
+                attrs: ast::AttrVec::new(),
                 kind: ast::AssocItemKind::TyAlias(Box::new(ast::TyAlias {
                     defaultness: ast::Defaultness::Final,
                     generics: Generics::default(),
@@ -716,7 +716,7 @@ impl<'a> TraitDef<'a> {
         let self_type = cx.ty_path(path);
 
         let attr = cx.attribute(cx.meta_word(self.span, sym::automatically_derived));
-        let attrs = vec![attr];
+        let attrs = vec![attr].into();
         let opt_trait_ref = Some(trait_ref);
 
         cx.item(
diff --git a/compiler/rustc_builtin_macros/src/deriving/hash.rs b/compiler/rustc_builtin_macros/src/deriving/hash.rs
index 9aa170bec14d8..f1f02e7ce7787 100644
--- a/compiler/rustc_builtin_macros/src/deriving/hash.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/hash.rs
@@ -2,7 +2,7 @@ use crate::deriving::generic::ty::*;
 use crate::deriving::generic::*;
 use crate::deriving::{path_std, pathvec_std};
 
-use rustc_ast::{MetaItem, Mutability};
+use rustc_ast::{AttrVec, MetaItem, Mutability};
 use rustc_expand::base::{Annotatable, ExtCtxt};
 use rustc_span::symbol::sym;
 use rustc_span::Span;
@@ -31,7 +31,7 @@ pub fn expand_deriving_hash(
             explicit_self: true,
             nonself_args: vec![(Ref(Box::new(Path(arg)), Mutability::Mut), sym::state)],
             ret_ty: Unit,
-            attributes: vec![],
+            attributes: AttrVec::new(),
             unify_fieldless_variants: true,
             combine_substructure: combine_substructure(Box::new(|a, b, c| {
                 hash_substructure(a, b, c)
diff --git a/compiler/rustc_builtin_macros/src/deriving/mod.rs b/compiler/rustc_builtin_macros/src/deriving/mod.rs
index c1ca089da221f..a65d0bad6de80 100644
--- a/compiler/rustc_builtin_macros/src/deriving/mod.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/mod.rs
@@ -164,7 +164,7 @@ fn inject_impl_of_structural_trait(
 
     // Keep the lint and stability attributes of the original item, to control
     // how the generated implementation is linted.
-    let mut attrs = Vec::new();
+    let mut attrs = ast::AttrVec::new();
     attrs.extend(
         item.attrs
             .iter()
diff --git a/compiler/rustc_builtin_macros/src/global_allocator.rs b/compiler/rustc_builtin_macros/src/global_allocator.rs
index 36cfbba45dacc..2bad9bbce6650 100644
--- a/compiler/rustc_builtin_macros/src/global_allocator.rs
+++ b/compiler/rustc_builtin_macros/src/global_allocator.rs
@@ -4,7 +4,7 @@ use rustc_ast::expand::allocator::{
     AllocatorKind, AllocatorMethod, AllocatorTy, ALLOCATOR_METHODS,
 };
 use rustc_ast::ptr::P;
-use rustc_ast::{self as ast, Attribute, Expr, FnHeader, FnSig, Generics, Param, StmtKind};
+use rustc_ast::{self as ast, AttrVec, Expr, FnHeader, FnSig, Generics, Param, StmtKind};
 use rustc_ast::{Fn, ItemKind, Mutability, Stmt, Ty, TyKind, Unsafe};
 use rustc_expand::base::{Annotatable, ExtCtxt};
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
@@ -113,10 +113,10 @@ impl AllocFnFactory<'_, '_> {
         self.cx.expr_call(self.ty_span, method, args)
     }
 
-    fn attrs(&self) -> Vec<Attribute> {
+    fn attrs(&self) -> AttrVec {
         let special = sym::rustc_std_internal_symbol;
         let special = self.cx.meta_word(self.span, special);
-        vec![self.cx.attribute(special)]
+        vec![self.cx.attribute(special)].into()
     }
 
     fn arg_ty(
diff --git a/compiler/rustc_builtin_macros/src/proc_macro_harness.rs b/compiler/rustc_builtin_macros/src/proc_macro_harness.rs
index 5cfda33491d5b..ebe1c3663e3a7 100644
--- a/compiler/rustc_builtin_macros/src/proc_macro_harness.rs
+++ b/compiler/rustc_builtin_macros/src/proc_macro_harness.rs
@@ -281,7 +281,7 @@ fn mk_decls(cx: &mut ExtCtxt<'_>, macros: &[ProcMacro]) -> P<ast::Item> {
     let span = DUMMY_SP.with_def_site_ctxt(expn_id.to_expn_id());
 
     let proc_macro = Ident::new(sym::proc_macro, span);
-    let krate = cx.item(span, proc_macro, Vec::new(), ast::ItemKind::ExternCrate(None));
+    let krate = cx.item(span, proc_macro, ast::AttrVec::new(), ast::ItemKind::ExternCrate(None));
 
     let bridge = Ident::new(sym::bridge, span);
     let client = Ident::new(sym::client, span);
diff --git a/compiler/rustc_builtin_macros/src/standard_library_imports.rs b/compiler/rustc_builtin_macros/src/standard_library_imports.rs
index 09ad5f9b3eaa9..90ea1e457ba80 100644
--- a/compiler/rustc_builtin_macros/src/standard_library_imports.rs
+++ b/compiler/rustc_builtin_macros/src/standard_library_imports.rs
@@ -51,7 +51,7 @@ pub fn inject(
             cx.item(
                 span,
                 ident,
-                vec![cx.attribute(cx.meta_word(span, sym::macro_use))],
+                vec![cx.attribute(cx.meta_word(span, sym::macro_use))].into(),
                 ast::ItemKind::ExternCrate(None),
             ),
         );
@@ -78,7 +78,7 @@ pub fn inject(
     let use_item = cx.item(
         span,
         Ident::empty(),
-        vec![cx.attribute(cx.meta_word(span, sym::prelude_import))],
+        vec![cx.attribute(cx.meta_word(span, sym::prelude_import))].into(),
         ast::ItemKind::Use(ast::UseTree {
             prefix: cx.path(span, import_path),
             kind: ast::UseTreeKind::Glob,
diff --git a/compiler/rustc_builtin_macros/src/test.rs b/compiler/rustc_builtin_macros/src/test.rs
index e20375689f3d1..03c84f5ec2a74 100644
--- a/compiler/rustc_builtin_macros/src/test.rs
+++ b/compiler/rustc_builtin_macros/src/test.rs
@@ -227,7 +227,8 @@ pub fn expand_test_or_bench(
             )),
             // #[rustc_test_marker]
             cx.attribute(cx.meta_word(attr_sp, sym::rustc_test_marker)),
-        ],
+        ]
+        .into(),
         // const $ident: test::TestDescAndFn =
         ast::ItemKind::Const(
             ast::Defaultness::Final,
@@ -334,7 +335,7 @@ pub fn expand_test_or_bench(
     });
 
     // extern crate test
-    let test_extern = cx.item(sp, test_id, vec![], ast::ItemKind::ExternCrate(None));
+    let test_extern = cx.item(sp, test_id, ast::AttrVec::new(), ast::ItemKind::ExternCrate(None));
 
     tracing::debug!("synthetic test item:\n{}\n", pprust::item_to_string(&test_const));
 
diff --git a/compiler/rustc_builtin_macros/src/test_harness.rs b/compiler/rustc_builtin_macros/src/test_harness.rs
index 0ebe29df95f20..093f0f10a3867 100644
--- a/compiler/rustc_builtin_macros/src/test_harness.rs
+++ b/compiler/rustc_builtin_macros/src/test_harness.rs
@@ -298,8 +298,10 @@ fn mk_main(cx: &mut TestCtxt<'_>) -> P<ast::Item> {
     let call_test_main = ecx.stmt_expr(call_test_main);
 
     // extern crate test
-    let test_extern_stmt =
-        ecx.stmt_item(sp, ecx.item(sp, test_id, vec![], ast::ItemKind::ExternCrate(None)));
+    let test_extern_stmt = ecx.stmt_item(
+        sp,
+        ecx.item(sp, test_id, ast::AttrVec::new(), ast::ItemKind::ExternCrate(None)),
+    );
 
     // #[rustc_main]
     let main_meta = ecx.meta_word(sp, sym::rustc_main);
@@ -333,7 +335,7 @@ fn mk_main(cx: &mut TestCtxt<'_>) -> P<ast::Item> {
 
     let main = P(ast::Item {
         ident: main_id,
-        attrs: vec![main_attr],
+        attrs: vec![main_attr].into(),
         id: ast::DUMMY_NODE_ID,
         kind: main,
         vis: ast::Visibility { span: sp, kind: ast::VisibilityKind::Public, tokens: None },
diff --git a/compiler/rustc_codegen_cranelift/example/alloc_system.rs b/compiler/rustc_codegen_cranelift/example/alloc_system.rs
index cf95c89bc3156..50261c1939739 100644
--- a/compiler/rustc_codegen_cranelift/example/alloc_system.rs
+++ b/compiler/rustc_codegen_cranelift/example/alloc_system.rs
@@ -94,7 +94,7 @@ mod platform {
     struct Header(*mut u8);
     const HEAP_ZERO_MEMORY: DWORD = 0x00000008;
     unsafe fn get_header<'a>(ptr: *mut u8) -> &'a mut Header {
-        &mut *(ptr as *mut Header).offset(-1)
+        &mut *(ptr as *mut Header).sub(1)
     }
     unsafe fn align_ptr(ptr: *mut u8, align: usize) -> *mut u8 {
         let aligned = ptr.add(align - (ptr as usize & (align - 1)));
diff --git a/compiler/rustc_codegen_gcc/example/alloc_system.rs b/compiler/rustc_codegen_gcc/example/alloc_system.rs
index 5f66ca67f2d40..89661918d05a5 100644
--- a/compiler/rustc_codegen_gcc/example/alloc_system.rs
+++ b/compiler/rustc_codegen_gcc/example/alloc_system.rs
@@ -156,7 +156,7 @@ mod platform {
     struct Header(*mut u8);
     const HEAP_ZERO_MEMORY: DWORD = 0x00000008;
     unsafe fn get_header<'a>(ptr: *mut u8) -> &'a mut Header {
-        &mut *(ptr as *mut Header).offset(-1)
+        &mut *(ptr as *mut Header).sub(1)
     }
     unsafe fn align_ptr(ptr: *mut u8, align: usize) -> *mut u8 {
         let aligned = ptr.add(align - (ptr as usize & (align - 1)));
diff --git a/compiler/rustc_const_eval/src/errors.rs b/compiler/rustc_const_eval/src/errors.rs
index a463fe7b970f4..01619dee0e42f 100644
--- a/compiler/rustc_const_eval/src/errors.rs
+++ b/compiler/rustc_const_eval/src/errors.rs
@@ -3,7 +3,7 @@ use rustc_macros::SessionDiagnostic;
 use rustc_span::Span;
 
 #[derive(SessionDiagnostic)]
-#[error(const_eval::unstable_in_stable)]
+#[diag(const_eval::unstable_in_stable)]
 pub(crate) struct UnstableInStable {
     pub gate: String,
     #[primary_span]
@@ -22,14 +22,14 @@ pub(crate) struct UnstableInStable {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(const_eval::thread_local_access, code = "E0625")]
+#[diag(const_eval::thread_local_access, code = "E0625")]
 pub(crate) struct NonConstOpErr {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(const_eval::static_access, code = "E0013")]
+#[diag(const_eval::static_access, code = "E0013")]
 #[help]
 pub(crate) struct StaticAccessErr {
     #[primary_span]
@@ -41,7 +41,7 @@ pub(crate) struct StaticAccessErr {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(const_eval::raw_ptr_to_int)]
+#[diag(const_eval::raw_ptr_to_int)]
 #[note]
 #[note(const_eval::note2)]
 pub(crate) struct RawPtrToIntErr {
@@ -50,7 +50,7 @@ pub(crate) struct RawPtrToIntErr {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(const_eval::raw_ptr_comparison)]
+#[diag(const_eval::raw_ptr_comparison)]
 #[note]
 pub(crate) struct RawPtrComparisonErr {
     #[primary_span]
@@ -58,14 +58,14 @@ pub(crate) struct RawPtrComparisonErr {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(const_eval::panic_non_str)]
+#[diag(const_eval::panic_non_str)]
 pub(crate) struct PanicNonStrErr {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(const_eval::mut_deref, code = "E0658")]
+#[diag(const_eval::mut_deref, code = "E0658")]
 pub(crate) struct MutDerefErr {
     #[primary_span]
     pub span: Span,
@@ -73,7 +73,7 @@ pub(crate) struct MutDerefErr {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(const_eval::transient_mut_borrow, code = "E0658")]
+#[diag(const_eval::transient_mut_borrow, code = "E0658")]
 pub(crate) struct TransientMutBorrowErr {
     #[primary_span]
     pub span: Span,
@@ -81,7 +81,7 @@ pub(crate) struct TransientMutBorrowErr {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(const_eval::transient_mut_borrow_raw, code = "E0658")]
+#[diag(const_eval::transient_mut_borrow_raw, code = "E0658")]
 pub(crate) struct TransientMutBorrowErrRaw {
     #[primary_span]
     pub span: Span,
diff --git a/compiler/rustc_data_structures/src/map_in_place.rs b/compiler/rustc_data_structures/src/map_in_place.rs
index 874de03d37ac6..d912211443a89 100644
--- a/compiler/rustc_data_structures/src/map_in_place.rs
+++ b/compiler/rustc_data_structures/src/map_in_place.rs
@@ -1,3 +1,4 @@
+use crate::thin_vec::ThinVec;
 use smallvec::{Array, SmallVec};
 use std::ptr;
 
@@ -15,94 +16,64 @@ pub trait MapInPlace<T>: Sized {
         I: IntoIterator<Item = T>;
 }
 
-impl<T> MapInPlace<T> for Vec<T> {
-    fn flat_map_in_place<F, I>(&mut self, mut f: F)
-    where
-        F: FnMut(T) -> I,
-        I: IntoIterator<Item = T>,
-    {
-        let mut read_i = 0;
-        let mut write_i = 0;
-        unsafe {
-            let mut old_len = self.len();
-            self.set_len(0); // make sure we just leak elements in case of panic
+// The implementation of this method is syntactically identical for all the
+// different vector types.
+macro_rules! flat_map_in_place {
+    () => {
+        fn flat_map_in_place<F, I>(&mut self, mut f: F)
+        where
+            F: FnMut(T) -> I,
+            I: IntoIterator<Item = T>,
+        {
+            let mut read_i = 0;
+            let mut write_i = 0;
+            unsafe {
+                let mut old_len = self.len();
+                self.set_len(0); // make sure we just leak elements in case of panic
 
-            while read_i < old_len {
-                // move the read_i'th item out of the vector and map it
-                // to an iterator
-                let e = ptr::read(self.as_ptr().add(read_i));
-                let iter = f(e).into_iter();
-                read_i += 1;
+                while read_i < old_len {
+                    // move the read_i'th item out of the vector and map it
+                    // to an iterator
+                    let e = ptr::read(self.as_ptr().add(read_i));
+                    let iter = f(e).into_iter();
+                    read_i += 1;
 
-                for e in iter {
-                    if write_i < read_i {
-                        ptr::write(self.as_mut_ptr().add(write_i), e);
-                        write_i += 1;
-                    } else {
-                        // If this is reached we ran out of space
-                        // in the middle of the vector.
-                        // However, the vector is in a valid state here,
-                        // so we just do a somewhat inefficient insert.
-                        self.set_len(old_len);
-                        self.insert(write_i, e);
+                    for e in iter {
+                        if write_i < read_i {
+                            ptr::write(self.as_mut_ptr().add(write_i), e);
+                            write_i += 1;
+                        } else {
+                            // If this is reached we ran out of space
+                            // in the middle of the vector.
+                            // However, the vector is in a valid state here,
+                            // so we just do a somewhat inefficient insert.
+                            self.set_len(old_len);
+                            self.insert(write_i, e);
 
-                        old_len = self.len();
-                        self.set_len(0);
+                            old_len = self.len();
+                            self.set_len(0);
 
-                        read_i += 1;
-                        write_i += 1;
+                            read_i += 1;
+                            write_i += 1;
+                        }
                     }
                 }
-            }
 
-            // write_i tracks the number of actually written new items.
-            self.set_len(write_i);
+                // write_i tracks the number of actually written new items.
+                self.set_len(write_i);
+            }
         }
-    }
+    };
 }
 
-impl<T, A: Array<Item = T>> MapInPlace<T> for SmallVec<A> {
-    fn flat_map_in_place<F, I>(&mut self, mut f: F)
-    where
-        F: FnMut(T) -> I,
-        I: IntoIterator<Item = T>,
-    {
-        let mut read_i = 0;
-        let mut write_i = 0;
-        unsafe {
-            let mut old_len = self.len();
-            self.set_len(0); // make sure we just leak elements in case of panic
-
-            while read_i < old_len {
-                // move the read_i'th item out of the vector and map it
-                // to an iterator
-                let e = ptr::read(self.as_ptr().add(read_i));
-                let iter = f(e).into_iter();
-                read_i += 1;
-
-                for e in iter {
-                    if write_i < read_i {
-                        ptr::write(self.as_mut_ptr().add(write_i), e);
-                        write_i += 1;
-                    } else {
-                        // If this is reached we ran out of space
-                        // in the middle of the vector.
-                        // However, the vector is in a valid state here,
-                        // so we just do a somewhat inefficient insert.
-                        self.set_len(old_len);
-                        self.insert(write_i, e);
-
-                        old_len = self.len();
-                        self.set_len(0);
+impl<T> MapInPlace<T> for Vec<T> {
+    flat_map_in_place!();
+}
 
-                        read_i += 1;
-                        write_i += 1;
-                    }
-                }
-            }
+impl<T, A: Array<Item = T>> MapInPlace<T> for SmallVec<A> {
+    flat_map_in_place!();
+}
 
-            // write_i tracks the number of actually written new items.
-            self.set_len(write_i);
-        }
-    }
+impl<T> MapInPlace<T> for ThinVec<T> {
+    flat_map_in_place!();
 }
diff --git a/compiler/rustc_data_structures/src/thin_vec.rs b/compiler/rustc_data_structures/src/thin_vec.rs
index 716259142d18b..fce42e709ab74 100644
--- a/compiler/rustc_data_structures/src/thin_vec.rs
+++ b/compiler/rustc_data_structures/src/thin_vec.rs
@@ -27,6 +27,51 @@ impl<T> ThinVec<T> {
             ThinVec(None) => *self = vec![item].into(),
         }
     }
+
+    /// Note: if `set_len(0)` is called on a non-empty `ThinVec`, it will
+    /// remain in the `Some` form. This is required for some code sequences
+    /// (such as the one in `flat_map_in_place`) that call `set_len(0)` before
+    /// an operation that might panic, and then call `set_len(n)` again
+    /// afterwards.
+    pub unsafe fn set_len(&mut self, new_len: usize) {
+        match *self {
+            ThinVec(None) => {
+                // A prerequisite of `Vec::set_len` is that `new_len` must be
+                // less than or equal to capacity(). The same applies here.
+                if new_len != 0 {
+                    panic!("unsafe ThinVec::set_len({})", new_len);
+                }
+            }
+            ThinVec(Some(ref mut vec)) => vec.set_len(new_len),
+        }
+    }
+
+    pub fn insert(&mut self, index: usize, value: T) {
+        match *self {
+            ThinVec(None) => {
+                if index == 0 {
+                    *self = vec![value].into();
+                } else {
+                    panic!("invalid ThinVec::insert");
+                }
+            }
+            ThinVec(Some(ref mut vec)) => vec.insert(index, value),
+        }
+    }
+
+    pub fn remove(&mut self, index: usize) -> T {
+        match self {
+            ThinVec(None) => panic!("invalid ThinVec::remove"),
+            ThinVec(Some(vec)) => vec.remove(index),
+        }
+    }
+
+    pub fn as_slice(&self) -> &[T] {
+        match self {
+            ThinVec(None) => &[],
+            ThinVec(Some(vec)) => vec.as_slice(),
+        }
+    }
 }
 
 impl<T> From<Vec<T>> for ThinVec<T> {
diff --git a/compiler/rustc_driver/src/lib.rs b/compiler/rustc_driver/src/lib.rs
index 94639bf8e1ee4..dac8df7dc55e0 100644
--- a/compiler/rustc_driver/src/lib.rs
+++ b/compiler/rustc_driver/src/lib.rs
@@ -1070,7 +1070,7 @@ pub fn handle_options(args: &[String]) -> Option<getopts::Matches> {
     Some(matches)
 }
 
-fn parse_crate_attrs<'a>(sess: &'a Session, input: &Input) -> PResult<'a, Vec<ast::Attribute>> {
+fn parse_crate_attrs<'a>(sess: &'a Session, input: &Input) -> PResult<'a, ast::AttrVec> {
     match input {
         Input::File(ifile) => rustc_parse::parse_crate_attrs_from_file(ifile, &sess.parse_sess),
         Input::Str { name, input } => rustc_parse::parse_crate_attrs_from_source_str(
diff --git a/compiler/rustc_error_messages/locales/en-US/borrowck.ftl b/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
index 02db2fae7c46e..d89053a99d277 100644
--- a/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
+++ b/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
@@ -13,21 +13,21 @@ borrowck_could_not_normalize =
 
 borrowck_higher_ranked_subtype_error =
     higher-ranked subtype error
-  
-generic_does_not_live_long_enough =
+
+borrowck_generic_does_not_live_long_enough =
     `{$kind}` does not live long enough
-    
-borrowck_move_borrowed = 
+
+borrowck_move_borrowed =
     cannot move out of `{$desc}` beacause it is borrowed
-    
-borrowck_var_better_not_mut = 
+
+borrowck_var_does_not_need_mut =
     variable does not need to be mutable
     .suggestion = remove this `mut`
 
-borrowck_const_not_used_in_type_alias = 
+borrowck_const_not_used_in_type_alias =
     const parameter `{$ct}` is part of concrete type but not used in parameter list for the `impl Trait` type alias
-    
-borrowck_var_cannot_escape_closure = 
+
+borrowck_var_cannot_escape_closure =
     captured variable cannot escape `FnMut` closure body
     .upvar_def = variable defined here
     .upvar = variable captured here
@@ -35,23 +35,21 @@ borrowck_var_cannot_escape_closure =
     .note = `FnMut` closures only have access to their captured variables while they are executing...
     .cannot_escape = ...therefore, they cannot allow references to captured variables to escape
 
-borrowck_returned_closure_escaped = 
+borrowck_returned_closure_escaped =
     returns a closure that contains a reference to a captured variable, which then escapes the closure body
 
-borrowck_returned_async_block_escaped = 
+borrowck_returned_async_block_escaped =
     returns an `async` block that contains a reference to a captured variable, which then escapes the closure body
 
-borrowck_returned_ref_escaped = 
+borrowck_returned_ref_escaped =
     returns a reference to a captured variable which escapes the closure body
 
 borrowck_lifetime_constraints_error =
     lifetime may not live long enough
-    
+
 borrowck_returned_lifetime_wrong =
     {$mir_def_name} was supposed to return data with lifetime `{$outlived_fr_name}` but it is returning data with lifetime `{$fr_name}`
 
 borrowck_returned_lifetime_short =
     {$category_desc}requires that `{$free_region_name}` must outlive `{$outlived_fr_name}`"
-    
-borrowck_impl_require_static =
-    the used `impl` has a `'static` requirement
\ No newline at end of file
+
diff --git a/compiler/rustc_error_messages/locales/en-US/expand.ftl b/compiler/rustc_error_messages/locales/en-US/expand.ftl
index ee76a4f45005d..5720591154f99 100644
--- a/compiler/rustc_error_messages/locales/en-US/expand.ftl
+++ b/compiler/rustc_error_messages/locales/en-US/expand.ftl
@@ -4,10 +4,10 @@ expand_explain_doc_comment_outer =
 expand_explain_doc_comment_inner =
     inner doc comments expand to `#![doc = "..."]`, which is what this macro attempted to match
 
-expand_expr_repeat_no_syntax_vars = 
+expand_expr_repeat_no_syntax_vars =
     attempted to repeat an expression containing no syntax variables matched as repeating at this depth
 
-expand_must_repeat_once = 
+expand_must_repeat_once =
     this must repeat at least once
 
 expand_count_repetition_misplaced =
@@ -19,4 +19,4 @@ expand_meta_var_expr_unrecognized_var =
 expand_var_still_repeating =
     variable '{$ident}' is still repeating at this depth
 
-expand_meta_var_dif_seq_matchers = {$msg}
\ No newline at end of file
+expand_meta_var_dif_seq_matchers = {$msg}
diff --git a/compiler/rustc_errors/src/diagnostic_builder.rs b/compiler/rustc_errors/src/diagnostic_builder.rs
index 04159bff4ff41..61d767a1cc6b4 100644
--- a/compiler/rustc_errors/src/diagnostic_builder.rs
+++ b/compiler/rustc_errors/src/diagnostic_builder.rs
@@ -84,6 +84,13 @@ pub trait EmissionGuarantee: Sized {
     /// of `Self` without actually performing the emission.
     #[track_caller]
     fn diagnostic_builder_emit_producing_guarantee(db: &mut DiagnosticBuilder<'_, Self>) -> Self;
+
+    /// Creates a new `DiagnosticBuilder` that will return this type of guarantee.
+    #[track_caller]
+    fn make_diagnostic_builder(
+        handler: &Handler,
+        msg: impl Into<DiagnosticMessage>,
+    ) -> DiagnosticBuilder<'_, Self>;
 }
 
 /// Private module for sealing the `IsError` helper trait.
@@ -166,6 +173,15 @@ impl EmissionGuarantee for ErrorGuaranteed {
             }
         }
     }
+
+    fn make_diagnostic_builder(
+        handler: &Handler,
+        msg: impl Into<DiagnosticMessage>,
+    ) -> DiagnosticBuilder<'_, Self> {
+        DiagnosticBuilder::new_guaranteeing_error::<_, { Level::Error { lint: false } }>(
+            handler, msg,
+        )
+    }
 }
 
 impl<'a> DiagnosticBuilder<'a, ()> {
@@ -208,6 +224,13 @@ impl EmissionGuarantee for () {
             DiagnosticBuilderState::AlreadyEmittedOrDuringCancellation => {}
         }
     }
+
+    fn make_diagnostic_builder(
+        handler: &Handler,
+        msg: impl Into<DiagnosticMessage>,
+    ) -> DiagnosticBuilder<'_, Self> {
+        DiagnosticBuilder::new(handler, Level::Warning(None), msg)
+    }
 }
 
 impl<'a> DiagnosticBuilder<'a, !> {
@@ -247,6 +270,13 @@ impl EmissionGuarantee for ! {
         // Then fatally error, returning `!`
         crate::FatalError.raise()
     }
+
+    fn make_diagnostic_builder(
+        handler: &Handler,
+        msg: impl Into<DiagnosticMessage>,
+    ) -> DiagnosticBuilder<'_, Self> {
+        DiagnosticBuilder::new_fatal(handler, msg)
+    }
 }
 
 /// In general, the `DiagnosticBuilder` uses deref to allow access to
diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
index 18e84b70b1b10..9b9c334d4dfcc 100644
--- a/compiler/rustc_errors/src/lib.rs
+++ b/compiler/rustc_errors/src/lib.rs
@@ -641,6 +641,15 @@ impl Handler {
         self.inner.borrow_mut().emit_stashed_diagnostics()
     }
 
+    /// Construct a builder with the `msg` at the level appropriate for the specific `EmissionGuarantee`.
+    #[rustc_lint_diagnostics]
+    pub fn struct_diagnostic<G: EmissionGuarantee>(
+        &self,
+        msg: impl Into<DiagnosticMessage>,
+    ) -> DiagnosticBuilder<'_, G> {
+        G::make_diagnostic_builder(self, msg)
+    }
+
     /// Construct a builder at the `Warning` level at the given `span` and with the `msg`.
     ///
     /// Attempting to `.emit()` the builder will only emit if either:
diff --git a/compiler/rustc_expand/src/base.rs b/compiler/rustc_expand/src/base.rs
index 852ea806b20ff..df56e032988c6 100644
--- a/compiler/rustc_expand/src/base.rs
+++ b/compiler/rustc_expand/src/base.rs
@@ -6,7 +6,7 @@ use rustc_ast::ptr::P;
 use rustc_ast::token::{self, Nonterminal};
 use rustc_ast::tokenstream::TokenStream;
 use rustc_ast::visit::{AssocCtxt, Visitor};
-use rustc_ast::{self as ast, Attribute, HasAttrs, Item, NodeId, PatKind};
+use rustc_ast::{self as ast, AttrVec, Attribute, HasAttrs, Item, NodeId, PatKind};
 use rustc_attr::{self as attr, Deprecation, Stability};
 use rustc_data_structures::fx::{FxHashSet, FxIndexMap};
 use rustc_data_structures::sync::{self, Lrc};
@@ -71,7 +71,7 @@ impl Annotatable {
         }
     }
 
-    pub fn visit_attrs(&mut self, f: impl FnOnce(&mut Vec<Attribute>)) {
+    pub fn visit_attrs(&mut self, f: impl FnOnce(&mut AttrVec)) {
         match self {
             Annotatable::Item(item) => item.visit_attrs(f),
             Annotatable::TraitItem(trait_item) => trait_item.visit_attrs(f),
diff --git a/compiler/rustc_expand/src/build.rs b/compiler/rustc_expand/src/build.rs
index 0440bca53b232..c4890b4a9c413 100644
--- a/compiler/rustc_expand/src/build.rs
+++ b/compiler/rustc_expand/src/build.rs
@@ -575,7 +575,7 @@ impl<'a> ExtCtxt<'a> {
         &self,
         span: Span,
         name: Ident,
-        attrs: Vec<ast::Attribute>,
+        attrs: ast::AttrVec,
         kind: ast::ItemKind,
     ) -> P<ast::Item> {
         // FIXME: Would be nice if our generated code didn't violate
@@ -603,7 +603,7 @@ impl<'a> ExtCtxt<'a> {
         mutbl: ast::Mutability,
         expr: P<ast::Expr>,
     ) -> P<ast::Item> {
-        self.item(span, name, Vec::new(), ast::ItemKind::Static(ty, mutbl, Some(expr)))
+        self.item(span, name, AttrVec::new(), ast::ItemKind::Static(ty, mutbl, Some(expr)))
     }
 
     pub fn item_const(
@@ -614,7 +614,7 @@ impl<'a> ExtCtxt<'a> {
         expr: P<ast::Expr>,
     ) -> P<ast::Item> {
         let def = ast::Defaultness::Final;
-        self.item(span, name, Vec::new(), ast::ItemKind::Const(def, ty, Some(expr)))
+        self.item(span, name, AttrVec::new(), ast::ItemKind::Const(def, ty, Some(expr)))
     }
 
     pub fn attribute(&self, mi: ast::MetaItem) -> ast::Attribute {
diff --git a/compiler/rustc_expand/src/config.rs b/compiler/rustc_expand/src/config.rs
index 3e1acf4382d5b..48ee23d2c3d18 100644
--- a/compiler/rustc_expand/src/config.rs
+++ b/compiler/rustc_expand/src/config.rs
@@ -215,7 +215,7 @@ pub fn features(
     let features = match strip_unconfigured.configure_krate_attrs(krate.attrs) {
         None => {
             // The entire crate is unconfigured.
-            krate.attrs = Vec::new();
+            krate.attrs = ast::AttrVec::new();
             krate.items = Vec::new();
             Features::default()
         }
@@ -265,7 +265,7 @@ impl<'a> StripUnconfigured<'a> {
         }
     }
 
-    fn configure_krate_attrs(&self, mut attrs: Vec<ast::Attribute>) -> Option<Vec<ast::Attribute>> {
+    fn configure_krate_attrs(&self, mut attrs: ast::AttrVec) -> Option<ast::AttrVec> {
         attrs.flat_map_in_place(|attr| self.process_cfg_attr(attr));
         if self.in_cfg(&attrs) { Some(attrs) } else { None }
     }
@@ -292,9 +292,7 @@ impl<'a> StripUnconfigured<'a> {
             .iter()
             .flat_map(|(tree, spacing)| match tree.clone() {
                 AttrAnnotatedTokenTree::Attributes(mut data) => {
-                    let mut attrs: Vec<_> = std::mem::take(&mut data.attrs).into();
-                    attrs.flat_map_in_place(|attr| self.process_cfg_attr(attr));
-                    data.attrs = attrs.into();
+                    data.attrs.flat_map_in_place(|attr| self.process_cfg_attr(attr));
 
                     if self.in_cfg(&data.attrs) {
                         data.tokens = LazyTokenStream::new(
diff --git a/compiler/rustc_expand/src/errors.rs b/compiler/rustc_expand/src/errors.rs
index 0d7e137c7dd0c..0feae0debd227 100644
--- a/compiler/rustc_expand/src/errors.rs
+++ b/compiler/rustc_expand/src/errors.rs
@@ -3,28 +3,28 @@ use rustc_span::symbol::MacroRulesNormalizedIdent;
 use rustc_span::Span;
 
 #[derive(SessionDiagnostic)]
-#[error(expand::expr_repeat_no_syntax_vars)]
+#[diag(expand::expr_repeat_no_syntax_vars)]
 pub(crate) struct NoSyntaxVarsExprRepeat {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(expand::must_repeat_once)]
+#[diag(expand::must_repeat_once)]
 pub(crate) struct MustRepeatOnce {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(expand::count_repetition_misplaced)]
+#[diag(expand::count_repetition_misplaced)]
 pub(crate) struct CountRepetitionMisplaced {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(expand::meta_var_expr_unrecognized_var)]
+#[diag(expand::meta_var_expr_unrecognized_var)]
 pub(crate) struct MetaVarExprUnrecognizedVar {
     #[primary_span]
     pub span: Span,
@@ -32,7 +32,7 @@ pub(crate) struct MetaVarExprUnrecognizedVar {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(expand::var_still_repeating)]
+#[diag(expand::var_still_repeating)]
 pub(crate) struct VarStillRepeating {
     #[primary_span]
     pub span: Span,
@@ -40,7 +40,7 @@ pub(crate) struct VarStillRepeating {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(expand::meta_var_dif_seq_matchers)]
+#[diag(expand::meta_var_dif_seq_matchers)]
 pub(crate) struct MetaVarsDifSeqMatchers {
     #[primary_span]
     pub span: Span,
diff --git a/compiler/rustc_expand/src/expand.rs b/compiler/rustc_expand/src/expand.rs
index cc72dab84afa2..c2add852a0679 100644
--- a/compiler/rustc_expand/src/expand.rs
+++ b/compiler/rustc_expand/src/expand.rs
@@ -11,7 +11,7 @@ use rustc_ast::ptr::P;
 use rustc_ast::token::{self, Delimiter};
 use rustc_ast::tokenstream::TokenStream;
 use rustc_ast::visit::{self, AssocCtxt, Visitor};
-use rustc_ast::{AssocItemKind, AstNodeWrapper, AttrStyle, ExprKind, ForeignItemKind};
+use rustc_ast::{AssocItemKind, AstNodeWrapper, AttrStyle, AttrVec, ExprKind, ForeignItemKind};
 use rustc_ast::{HasAttrs, HasNodeId};
 use rustc_ast::{Inline, ItemKind, MacArgs, MacStmtStyle, MetaItemKind, ModKind};
 use rustc_ast::{NestedMetaItem, NodeId, PatKind, StmtKind, TyKind};
@@ -1001,7 +1001,7 @@ enum AddSemicolon {
 /// of functionality used by `InvocationCollector`.
 trait InvocationCollectorNode: HasAttrs + HasNodeId + Sized {
     type OutputTy = SmallVec<[Self; 1]>;
-    type AttrsTy: Deref<Target = [ast::Attribute]> = Vec<ast::Attribute>;
+    type AttrsTy: Deref<Target = [ast::Attribute]> = ast::AttrVec;
     const KIND: AstFragmentKind;
     fn to_annotatable(self) -> Annotatable;
     fn fragment_to_output(fragment: AstFragment) -> Self::OutputTy;
@@ -1333,7 +1333,7 @@ impl InvocationCollectorNode for ast::Stmt {
             }
             StmtKind::Item(item) => match item.into_inner() {
                 ast::Item { kind: ItemKind::MacCall(mac), attrs, .. } => {
-                    (mac.args.need_semicolon(), mac, attrs.into())
+                    (mac.args.need_semicolon(), mac, attrs)
                 }
                 _ => unreachable!(),
             },
@@ -1390,7 +1390,7 @@ impl InvocationCollectorNode for P<ast::Ty> {
     fn take_mac_call(self) -> (P<ast::MacCall>, Self::AttrsTy, AddSemicolon) {
         let node = self.into_inner();
         match node.kind {
-            TyKind::MacCall(mac) => (mac, Vec::new(), AddSemicolon::No),
+            TyKind::MacCall(mac) => (mac, AttrVec::new(), AddSemicolon::No),
             _ => unreachable!(),
         }
     }
@@ -1414,7 +1414,7 @@ impl InvocationCollectorNode for P<ast::Pat> {
     fn take_mac_call(self) -> (P<ast::MacCall>, Self::AttrsTy, AddSemicolon) {
         let node = self.into_inner();
         match node.kind {
-            PatKind::MacCall(mac) => (mac, Vec::new(), AddSemicolon::No),
+            PatKind::MacCall(mac) => (mac, AttrVec::new(), AddSemicolon::No),
             _ => unreachable!(),
         }
     }
@@ -1646,7 +1646,11 @@ impl<'a, 'b> InvocationCollector<'a, 'b> {
 
     fn expand_cfg_attr(&self, node: &mut impl HasAttrs, attr: ast::Attribute, pos: usize) {
         node.visit_attrs(|attrs| {
-            attrs.splice(pos..pos, self.cfg().expand_cfg_attr(attr, false));
+            // Repeated `insert` calls is inefficient, but the number of
+            // insertions is almost always 0 or 1 in practice.
+            for cfg in self.cfg().expand_cfg_attr(attr, false).into_iter().rev() {
+                attrs.insert(pos, cfg)
+            }
         });
     }
 
diff --git a/compiler/rustc_expand/src/module.rs b/compiler/rustc_expand/src/module.rs
index 0315d11634c6b..9002a24e42f9d 100644
--- a/compiler/rustc_expand/src/module.rs
+++ b/compiler/rustc_expand/src/module.rs
@@ -1,6 +1,6 @@
 use crate::base::ModuleData;
 use rustc_ast::ptr::P;
-use rustc_ast::{token, Attribute, Inline, Item, ModSpans};
+use rustc_ast::{token, AttrVec, Attribute, Inline, Item, ModSpans};
 use rustc_errors::{struct_span_err, DiagnosticBuilder, ErrorGuaranteed};
 use rustc_parse::new_parser_from_file;
 use rustc_parse::validate_attr;
@@ -48,7 +48,7 @@ pub(crate) fn parse_external_mod(
     span: Span, // The span to blame on errors.
     module: &ModuleData,
     mut dir_ownership: DirOwnership,
-    attrs: &mut Vec<Attribute>,
+    attrs: &mut AttrVec,
 ) -> ParsedExternalMod {
     // We bail on the first error, but that error does not cause a fatal error... (1)
     let result: Result<_, ModError<'_>> = try {
@@ -63,9 +63,9 @@ pub(crate) fn parse_external_mod(
 
         // Actually parse the external file as a module.
         let mut parser = new_parser_from_file(&sess.parse_sess, &mp.file_path, Some(span));
-        let (mut inner_attrs, items, inner_span) =
+        let (inner_attrs, items, inner_span) =
             parser.parse_mod(&token::Eof).map_err(|err| ModError::ParserError(err))?;
-        attrs.append(&mut inner_attrs);
+        attrs.extend(inner_attrs);
         (items, inner_span, mp.file_path)
     };
     // (1) ...instead, we return a dummy module.
diff --git a/compiler/rustc_expand/src/placeholders.rs b/compiler/rustc_expand/src/placeholders.rs
index 48918541e72fc..3b0d5ddb97b4e 100644
--- a/compiler/rustc_expand/src/placeholders.rs
+++ b/compiler/rustc_expand/src/placeholders.rs
@@ -24,7 +24,7 @@ pub fn placeholder(
     }
 
     let ident = Ident::empty();
-    let attrs = Vec::new();
+    let attrs = ast::AttrVec::new();
     let vis = vis.unwrap_or(ast::Visibility {
         span: DUMMY_SP,
         kind: ast::VisibilityKind::Inherited,
diff --git a/compiler/rustc_infer/src/infer/error_reporting/mod.rs b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
index 8fb5f159136be..59ea1f3f9de45 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/mod.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
@@ -740,12 +740,12 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                 err.help("...or use `match` instead of `let...else`");
             }
             _ => {
-                if let ObligationCauseCode::BindingObligation(_, binding_span) =
-                    cause.code().peel_derives()
+                if let ObligationCauseCode::BindingObligation(_, span)
+                | ObligationCauseCode::ExprBindingObligation(_, span, ..)
+                    = cause.code().peel_derives()
+                    && let TypeError::RegionsPlaceholderMismatch = terr
                 {
-                    if matches!(terr, TypeError::RegionsPlaceholderMismatch) {
-                        err.span_note(*binding_span, "the lifetime requirement is introduced here");
-                    }
+                    err.span_note(*span, "the lifetime requirement is introduced here");
                 }
             }
         }
diff --git a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/mismatched_static_lifetime.rs b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/mismatched_static_lifetime.rs
index 893ca3cf79d70..c20b96cae2e4f 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/mismatched_static_lifetime.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/mismatched_static_lifetime.rs
@@ -35,7 +35,8 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
         let ObligationCauseCode::MatchImpl(parent, impl_def_id) = code else {
             return None;
         };
-        let ObligationCauseCode::BindingObligation(_def_id, binding_span) = *parent.code() else {
+        let (ObligationCauseCode::BindingObligation(_, binding_span) | ObligationCauseCode::ExprBindingObligation(_, binding_span, ..))
+            = *parent.code() else {
             return None;
         };
         let mut err = self.tcx().sess.struct_span_err(cause.span, "incompatible lifetime on type");
diff --git a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/placeholder_error.rs b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/placeholder_error.rs
index 998699158ff48..d4db0751212f7 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/placeholder_error.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/placeholder_error.rs
@@ -211,7 +211,10 @@ impl<'tcx> NiceRegionError<'_, 'tcx> {
         );
         let mut err = self.tcx().sess.struct_span_err(span, &msg);
 
-        let leading_ellipsis = if let ObligationCauseCode::ItemObligation(def_id) = *cause.code() {
+        let leading_ellipsis = if let ObligationCauseCode::ItemObligation(def_id)
+        | ObligationCauseCode::ExprItemObligation(def_id, ..) =
+            *cause.code()
+        {
             err.span_label(span, "doesn't satisfy where-clause");
             err.span_label(
                 self.tcx().def_span(def_id),
diff --git a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs
index 9886c572a8aaf..f804569b0747e 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs
@@ -232,7 +232,7 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
                 ObligationCauseCode::MatchImpl(parent, ..) => parent.code(),
                 _ => cause.code(),
             }
-            && let (&ObligationCauseCode::ItemObligation(item_def_id), None) = (code, override_error_code)
+            && let (&ObligationCauseCode::ItemObligation(item_def_id) | &ObligationCauseCode::ExprItemObligation(item_def_id, ..), None) = (code, override_error_code)
         {
             // Same case of `impl Foo for dyn Bar { fn qux(&self) {} }` introducing a `'static`
             // lifetime as above, but called using a fully-qualified path to the method:
diff --git a/compiler/rustc_infer/src/infer/error_reporting/note.rs b/compiler/rustc_infer/src/infer/error_reporting/note.rs
index 8dabdfd55c7e8..8c465b0876002 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/note.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/note.rs
@@ -390,10 +390,12 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                 if matches!(
                     &trace.cause.code().peel_derives(),
                     ObligationCauseCode::BindingObligation(..)
+                        | ObligationCauseCode::ExprBindingObligation(..)
                 ) =>
             {
                 // Hack to get around the borrow checker because trace.cause has an `Rc`.
-                if let ObligationCauseCode::BindingObligation(_, span) =
+                if let ObligationCauseCode::BindingObligation(_, span)
+                | ObligationCauseCode::ExprBindingObligation(_, span, ..) =
                     &trace.cause.code().peel_derives()
                 {
                     let span = *span;
diff --git a/compiler/rustc_infer/src/infer/outlives/obligations.rs b/compiler/rustc_infer/src/infer/outlives/obligations.rs
index ad052f58ca854..dded0a0a6b1b4 100644
--- a/compiler/rustc_infer/src/infer/outlives/obligations.rs
+++ b/compiler/rustc_infer/src/infer/outlives/obligations.rs
@@ -97,7 +97,8 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> {
                 cause.span,
                 sup_type,
                 match cause.code().peel_derives() {
-                    ObligationCauseCode::BindingObligation(_, span) => Some(*span),
+                    ObligationCauseCode::BindingObligation(_, span)
+                    | ObligationCauseCode::ExprBindingObligation(_, span, ..) => Some(*span),
                     _ => None,
                 },
             )
diff --git a/compiler/rustc_interface/src/passes.rs b/compiler/rustc_interface/src/passes.rs
index e00d0b7d0d82f..014cf88389e44 100644
--- a/compiler/rustc_interface/src/passes.rs
+++ b/compiler/rustc_interface/src/passes.rs
@@ -265,7 +265,7 @@ impl LintStoreExpand for LintStoreExpandImpl<'_> {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(interface::ferris_identifier)]
+#[diag(interface::ferris_identifier)]
 struct FerrisIdentifier {
     #[primary_span]
     spans: Vec<Span>,
@@ -274,7 +274,7 @@ struct FerrisIdentifier {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(interface::emoji_identifier)]
+#[diag(interface::emoji_identifier)]
 struct EmojiIdentifier {
     #[primary_span]
     spans: Vec<Span>,
diff --git a/compiler/rustc_lint/src/types.rs b/compiler/rustc_lint/src/types.rs
index cafd2c6e67994..484e541afc587 100644
--- a/compiler/rustc_lint/src/types.rs
+++ b/compiler/rustc_lint/src/types.rs
@@ -1546,7 +1546,7 @@ impl InvalidAtomicOrdering {
 
         if matches!(fail_ordering, sym::Release | sym::AcqRel) {
             #[derive(LintDiagnostic)]
-            #[lint(lint::atomic_ordering_invalid)]
+            #[diag(lint::atomic_ordering_invalid)]
             #[help]
             struct InvalidAtomicOrderingDiag {
                 method: Symbol,
diff --git a/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
index b4314223722fc..05d2a214d0b79 100644
--- a/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
+++ b/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
@@ -31,6 +31,9 @@
 #include "llvm/Transforms/IPO/PassManagerBuilder.h"
 #include "llvm/Transforms/IPO/AlwaysInliner.h"
 #include "llvm/Transforms/IPO/FunctionImport.h"
+#if LLVM_VERSION_GE(15, 0)
+#include "llvm/Transforms/IPO/ThinLTOBitcodeWriter.h"
+#endif
 #include "llvm/Transforms/Utils/AddDiscriminators.h"
 #include "llvm/Transforms/Utils/FunctionImportUtils.h"
 #include "llvm/LTO/LTO.h"
@@ -1587,13 +1590,31 @@ LLVMRustThinLTOBufferCreate(LLVMModuleRef M, bool is_thin) {
   {
     raw_string_ostream OS(Ret->data);
     {
-      legacy::PassManager PM;
       if (is_thin) {
+#if LLVM_VERSION_LT(15, 0)
+        legacy::PassManager PM;
         PM.add(createWriteThinLTOBitcodePass(OS));
+        PM.run(*unwrap(M));
+#else
+        PassBuilder PB;
+        LoopAnalysisManager LAM;
+        FunctionAnalysisManager FAM;
+        CGSCCAnalysisManager CGAM;
+        ModuleAnalysisManager MAM;
+        PB.registerModuleAnalyses(MAM);
+        PB.registerCGSCCAnalyses(CGAM);
+        PB.registerFunctionAnalyses(FAM);
+        PB.registerLoopAnalyses(LAM);
+        PB.crossRegisterProxies(LAM, FAM, CGAM, MAM);
+        ModulePassManager MPM;
+        MPM.addPass(ThinLTOBitcodeWriterPass(OS, nullptr));
+        MPM.run(*unwrap(M), MAM);
+#endif
       } else {
+        legacy::PassManager PM;
         PM.add(createBitcodeWriterPass(OS));
+        PM.run(*unwrap(M));
       }
-      PM.run(*unwrap(M));
     }
   }
   return Ret.release();
diff --git a/compiler/rustc_macros/src/diagnostics/diagnostic.rs b/compiler/rustc_macros/src/diagnostics/diagnostic.rs
index 6b5b8b5932018..244edec284159 100644
--- a/compiler/rustc_macros/src/diagnostics/diagnostic.rs
+++ b/compiler/rustc_macros/src/diagnostics/diagnostic.rs
@@ -21,7 +21,7 @@ impl<'a> SessionDiagnosticDerive<'a> {
             builder: DiagnosticDeriveBuilder {
                 diag,
                 fields: build_field_mapping(&structure),
-                kind: None,
+                kind: DiagnosticDeriveKind::SessionDiagnostic,
                 code: None,
                 slug: None,
             },
@@ -34,49 +34,31 @@ impl<'a> SessionDiagnosticDerive<'a> {
         let SessionDiagnosticDerive { mut structure, sess, mut builder } = self;
 
         let ast = structure.ast();
-        let (implementation, param_ty) = {
+        let implementation = {
             if let syn::Data::Struct(..) = ast.data {
                 let preamble = builder.preamble(&structure);
                 let (attrs, args) = builder.body(&mut structure);
 
                 let span = ast.span().unwrap();
                 let diag = &builder.diag;
-                let init = match (builder.kind.value(), builder.slug.value()) {
-                    (None, _) => {
-                        span_err(span, "diagnostic kind not specified")
-                            .help("use the `#[error(...)]` attribute to create an error")
-                            .emit();
-                        return DiagnosticDeriveError::ErrorHandled.to_compile_error();
-                    }
-                    (Some(kind), None) => {
+                let init = match builder.slug.value() {
+                    None => {
                         span_err(span, "diagnostic slug not specified")
                             .help(&format!(
-                                "specify the slug as the first argument to the attribute, such as \
-                                 `#[{}(typeck::example_error)]`",
-                                kind.descr()
+                                "specify the slug as the first argument to the `#[diag(...)]` attribute, \
+                                such as `#[diag(typeck::example_error)]`",
                             ))
                             .emit();
                         return DiagnosticDeriveError::ErrorHandled.to_compile_error();
                     }
-                    (Some(DiagnosticDeriveKind::Lint), _) => {
-                        span_err(span, "only `#[error(..)]` and `#[warning(..)]` are supported")
-                            .help("use the `#[error(...)]` attribute to create a error")
-                            .emit();
-                        return DiagnosticDeriveError::ErrorHandled.to_compile_error();
-                    }
-                    (Some(DiagnosticDeriveKind::Error), Some(slug)) => {
-                        quote! {
-                            let mut #diag = #sess.struct_err(rustc_errors::fluent::#slug);
-                        }
-                    }
-                    (Some(DiagnosticDeriveKind::Warn), Some(slug)) => {
+                    Some(slug) => {
                         quote! {
-                            let mut #diag = #sess.struct_warn(rustc_errors::fluent::#slug);
+                            let mut #diag = #sess.struct_diagnostic(rustc_errors::fluent::#slug);
                         }
                     }
                 };
 
-                let implementation = quote! {
+                quote! {
                     #init
                     #preamble
                     match self {
@@ -86,18 +68,7 @@ impl<'a> SessionDiagnosticDerive<'a> {
                         #args
                     }
                     #diag
-                };
-                let param_ty = match builder.kind {
-                    Some((DiagnosticDeriveKind::Error, _)) => {
-                        quote! { rustc_errors::ErrorGuaranteed }
-                    }
-                    Some((DiagnosticDeriveKind::Lint | DiagnosticDeriveKind::Warn, _)) => {
-                        quote! { () }
-                    }
-                    _ => unreachable!(),
-                };
-
-                (implementation, param_ty)
+                }
             } else {
                 span_err(
                     ast.span().unwrap(),
@@ -105,20 +76,20 @@ impl<'a> SessionDiagnosticDerive<'a> {
                 )
                 .emit();
 
-                let implementation = DiagnosticDeriveError::ErrorHandled.to_compile_error();
-                let param_ty = quote! { rustc_errors::ErrorGuaranteed };
-                (implementation, param_ty)
+                DiagnosticDeriveError::ErrorHandled.to_compile_error()
             }
         };
 
         structure.gen_impl(quote! {
-            gen impl<'__session_diagnostic_sess> rustc_session::SessionDiagnostic<'__session_diagnostic_sess, #param_ty>
+            gen impl<'__session_diagnostic_sess, G>
+                    rustc_session::SessionDiagnostic<'__session_diagnostic_sess, G>
                     for @Self
+                where G: rustc_errors::EmissionGuarantee
             {
                 fn into_diagnostic(
                     self,
                     #sess: &'__session_diagnostic_sess rustc_session::parse::ParseSess
-                ) -> rustc_errors::DiagnosticBuilder<'__session_diagnostic_sess, #param_ty> {
+                ) -> rustc_errors::DiagnosticBuilder<'__session_diagnostic_sess, G> {
                     use rustc_errors::IntoDiagnosticArg;
                     #implementation
                 }
@@ -139,7 +110,7 @@ impl<'a> LintDiagnosticDerive<'a> {
             builder: DiagnosticDeriveBuilder {
                 diag,
                 fields: build_field_mapping(&structure),
-                kind: None,
+                kind: DiagnosticDeriveKind::LintDiagnostic,
                 code: None,
                 slug: None,
             },
@@ -158,30 +129,17 @@ impl<'a> LintDiagnosticDerive<'a> {
 
                 let diag = &builder.diag;
                 let span = ast.span().unwrap();
-                let init = match (builder.kind.value(), builder.slug.value()) {
-                    (None, _) => {
-                        span_err(span, "diagnostic kind not specified")
-                            .help("use the `#[error(...)]` attribute to create an error")
-                            .emit();
-                        return DiagnosticDeriveError::ErrorHandled.to_compile_error();
-                    }
-                    (Some(kind), None) => {
+                let init = match builder.slug.value() {
+                    None => {
                         span_err(span, "diagnostic slug not specified")
                             .help(&format!(
                                 "specify the slug as the first argument to the attribute, such as \
-                                 `#[{}(typeck::example_error)]`",
-                                kind.descr()
+                                 `#[diag(typeck::example_error)]`",
                             ))
                             .emit();
                         return DiagnosticDeriveError::ErrorHandled.to_compile_error();
                     }
-                    (Some(DiagnosticDeriveKind::Error | DiagnosticDeriveKind::Warn), _) => {
-                        span_err(span, "only `#[lint(..)]` is supported")
-                            .help("use the `#[lint(...)]` attribute to create a lint")
-                            .emit();
-                        return DiagnosticDeriveError::ErrorHandled.to_compile_error();
-                    }
-                    (Some(DiagnosticDeriveKind::Lint), Some(slug)) => {
+                    Some(slug) => {
                         quote! {
                             let mut #diag = #diag.build(rustc_errors::fluent::#slug);
                         }
diff --git a/compiler/rustc_macros/src/diagnostics/diagnostic_builder.rs b/compiler/rustc_macros/src/diagnostics/diagnostic_builder.rs
index 6c9561925fe8c..9df9fa4e9bf74 100644
--- a/compiler/rustc_macros/src/diagnostics/diagnostic_builder.rs
+++ b/compiler/rustc_macros/src/diagnostics/diagnostic_builder.rs
@@ -18,30 +18,15 @@ use syn::{
 };
 use synstructure::{BindingInfo, Structure};
 
-/// What kind of diagnostic is being derived - an error, a warning or a lint?
-#[derive(Copy, Clone)]
+/// What kind of diagnostic is being derived - a fatal/error/warning or a lint?
+#[derive(Copy, Clone, PartialEq, Eq)]
 pub(crate) enum DiagnosticDeriveKind {
-    /// `#[error(..)]`
-    Error,
-    /// `#[warn(..)]`
-    Warn,
-    /// `#[lint(..)]`
-    Lint,
-}
-
-impl DiagnosticDeriveKind {
-    /// Returns human-readable string corresponding to the kind.
-    pub fn descr(&self) -> &'static str {
-        match self {
-            DiagnosticDeriveKind::Error => "error",
-            DiagnosticDeriveKind::Warn => "warning",
-            DiagnosticDeriveKind::Lint => "lint",
-        }
-    }
+    SessionDiagnostic,
+    LintDiagnostic,
 }
 
 /// Tracks persistent information required for building up individual calls to diagnostic methods
-/// for generated diagnostic derives - both `SessionDiagnostic` for errors/warnings and
+/// for generated diagnostic derives - both `SessionDiagnostic` for fatal/errors/warnings and
 /// `LintDiagnostic` for lints.
 pub(crate) struct DiagnosticDeriveBuilder {
     /// The identifier to use for the generated `DiagnosticBuilder` instance.
@@ -51,8 +36,8 @@ pub(crate) struct DiagnosticDeriveBuilder {
     /// derive builder.
     pub fields: HashMap<String, TokenStream>,
 
-    /// Kind of diagnostic requested via the struct attribute.
-    pub kind: Option<(DiagnosticDeriveKind, proc_macro::Span)>,
+    /// Kind of diagnostic that should be derived.
+    pub kind: DiagnosticDeriveKind,
     /// Slug is a mandatory part of the struct attribute as corresponds to the Fluent message that
     /// has the actual diagnostic message.
     pub slug: Option<(Path, proc_macro::Span)>,
@@ -143,7 +128,7 @@ impl DiagnosticDeriveBuilder {
     }
 
     /// Establishes state in the `DiagnosticDeriveBuilder` resulting from the struct
-    /// attributes like `#[error(..)`, such as the diagnostic kind and slug. Generates
+    /// attributes like `#[diag(..)]`, such as the slug and error code. Generates
     /// diagnostic builder calls for setting error code and creating note/help messages.
     fn generate_structure_code_for_attr(
         &mut self,
@@ -156,15 +141,15 @@ impl DiagnosticDeriveBuilder {
         let name = name.as_str();
         let meta = attr.parse_meta()?;
 
-        let is_help_note_or_warn = matches!(name, "help" | "note" | "warn_");
+        let is_diag = name == "diag";
 
         let nested = match meta {
-            // Most attributes are lists, like `#[error(..)]`/`#[warning(..)]` for most cases or
+            // Most attributes are lists, like `#[diag(..)]` for most cases or
             // `#[help(..)]`/`#[note(..)]` when the user is specifying a alternative slug.
             Meta::List(MetaList { ref nested, .. }) => nested,
             // Subdiagnostics without spans can be applied to the type too, and these are just
-            // paths: `#[help]` and `#[note]`
-            Meta::Path(_) if is_help_note_or_warn => {
+            // paths: `#[help]`, `#[note]` and `#[warn_]`
+            Meta::Path(_) if !is_diag => {
                 let fn_name = if name == "warn_" {
                     Ident::new("warn", attr.span())
                 } else {
@@ -178,23 +163,21 @@ impl DiagnosticDeriveBuilder {
         // Check the kind before doing any further processing so that there aren't misleading
         // "no kind specified" errors if there are failures later.
         match name {
-            "error" => self.kind.set_once((DiagnosticDeriveKind::Error, span)),
-            "warning" => self.kind.set_once((DiagnosticDeriveKind::Warn, span)),
-            "lint" => self.kind.set_once((DiagnosticDeriveKind::Lint, span)),
-            "help" | "note" | "warn_" => (),
+            "error" | "warning" | "lint" => throw_invalid_attr!(attr, &meta, |diag| {
+                diag.help("`error`, `warning` and `lint` have been replaced by `diag`")
+            }),
+            "diag" | "help" | "note" | "warn_" => (),
             _ => throw_invalid_attr!(attr, &meta, |diag| {
-                diag.help(
-                    "only `error`, `warning`, `help`, `note` and `warn_` are valid attributes",
-                )
+                diag.help("only `diag`, `help`, `note` and `warn_` are valid attributes")
             }),
         }
 
-        // First nested element should always be the path, e.g. `#[error(typeck::invalid)]` or
+        // First nested element should always be the path, e.g. `#[diag(typeck::invalid)]` or
         // `#[help(typeck::another_help)]`.
         let mut nested_iter = nested.into_iter();
         if let Some(nested_attr) = nested_iter.next() {
             // Report an error if there are any other list items after the path.
-            if is_help_note_or_warn && nested_iter.next().is_some() {
+            if !is_diag && nested_iter.next().is_some() {
                 throw_invalid_nested_attr!(attr, &nested_attr, |diag| {
                     diag.help(
                         "`help`, `note` and `warn_` struct attributes can only have one argument",
@@ -203,16 +186,16 @@ impl DiagnosticDeriveBuilder {
             }
 
             match nested_attr {
-                NestedMeta::Meta(Meta::Path(path)) if is_help_note_or_warn => {
-                    let fn_name = proc_macro2::Ident::new(name, attr.span());
-                    return Ok(quote! { #diag.#fn_name(rustc_errors::fluent::#path); });
-                }
                 NestedMeta::Meta(Meta::Path(path)) => {
-                    self.slug.set_once((path.clone(), span));
+                    if is_diag {
+                        self.slug.set_once((path.clone(), span));
+                    } else {
+                        let fn_name = proc_macro2::Ident::new(name, attr.span());
+                        return Ok(quote! { #diag.#fn_name(rustc_errors::fluent::#path); });
+                    }
                 }
                 NestedMeta::Meta(meta @ Meta::NameValue(_))
-                    if !is_help_note_or_warn
-                        && meta.path().segments.last().unwrap().ident == "code" =>
+                    if is_diag && meta.path().segments.last().unwrap().ident == "code" =>
                 {
                     // don't error for valid follow-up attributes
                 }
@@ -346,10 +329,20 @@ impl DiagnosticDeriveBuilder {
                 Ok(quote! {})
             }
             "primary_span" => {
-                report_error_if_not_applied_to_span(attr, &info)?;
-                Ok(quote! {
-                    #diag.set_span(#binding);
-                })
+                match self.kind {
+                    DiagnosticDeriveKind::SessionDiagnostic => {
+                        report_error_if_not_applied_to_span(attr, &info)?;
+
+                        Ok(quote! {
+                            #diag.set_span(#binding);
+                        })
+                    }
+                    DiagnosticDeriveKind::LintDiagnostic => {
+                        throw_invalid_attr!(attr, &meta, |diag| {
+                            diag.help("the `primary_span` field attribute is not valid for lint diagnostics")
+                        })
+                    }
+                }
             }
             "label" => {
                 report_error_if_not_applied_to_span(attr, &info)?;
diff --git a/compiler/rustc_macros/src/diagnostics/mod.rs b/compiler/rustc_macros/src/diagnostics/mod.rs
index 733454cb2a747..2ff21e18ff853 100644
--- a/compiler/rustc_macros/src/diagnostics/mod.rs
+++ b/compiler/rustc_macros/src/diagnostics/mod.rs
@@ -23,7 +23,7 @@ use synstructure::Structure;
 /// # extern crate rust_middle;
 /// # use rustc_middle::ty::Ty;
 /// #[derive(SessionDiagnostic)]
-/// #[error(borrowck::move_out_of_borrow, code = "E0505")]
+/// #[diag(borrowck::move_out_of_borrow, code = "E0505")]
 /// pub struct MoveOutOfBorrowError<'tcx> {
 ///     pub name: Ident,
 ///     pub ty: Ty<'tcx>,
@@ -67,7 +67,7 @@ pub fn session_diagnostic_derive(s: Structure<'_>) -> TokenStream {
 ///
 /// ```ignore (rust)
 /// #[derive(LintDiagnostic)]
-/// #[lint(lint::atomic_ordering_invalid_fail_success)]
+/// #[diag(lint::atomic_ordering_invalid_fail_success)]
 /// pub struct AtomicOrderingInvalidLint {
 ///     method: Symbol,
 ///     success_ordering: Symbol,
diff --git a/compiler/rustc_macros/src/lib.rs b/compiler/rustc_macros/src/lib.rs
index e01d035767ba6..87d7ab6ed517b 100644
--- a/compiler/rustc_macros/src/lib.rs
+++ b/compiler/rustc_macros/src/lib.rs
@@ -129,9 +129,7 @@ decl_derive!([Lift, attributes(lift)] => lift::lift_derive);
 decl_derive!(
     [SessionDiagnostic, attributes(
         // struct attributes
-        warning,
-        error,
-        lint,
+        diag,
         help,
         note,
         warn_,
@@ -148,9 +146,7 @@ decl_derive!(
 decl_derive!(
     [LintDiagnostic, attributes(
         // struct attributes
-        warning,
-        error,
-        lint,
+        diag,
         help,
         note,
         warn_,
diff --git a/compiler/rustc_middle/src/traits/mod.rs b/compiler/rustc_middle/src/traits/mod.rs
index 72b848c3ee2dd..9b82320e556b3 100644
--- a/compiler/rustc_middle/src/traits/mod.rs
+++ b/compiler/rustc_middle/src/traits/mod.rs
@@ -234,13 +234,23 @@ pub enum ObligationCauseCode<'tcx> {
     /// This is the trait reference from the given projection.
     ProjectionWf(ty::ProjectionTy<'tcx>),
 
-    /// In an impl of trait `X` for type `Y`, type `Y` must
-    /// also implement all supertraits of `X`.
+    /// Must satisfy all of the where-clause predicates of the
+    /// given item.
     ItemObligation(DefId),
 
-    /// Like `ItemObligation`, but with extra detail on the source of the obligation.
+    /// Like `ItemObligation`, but carries the span of the
+    /// predicate when it can be identified.
     BindingObligation(DefId, Span),
 
+    /// Like `ItemObligation`, but carries the `HirId` of the
+    /// expression that caused the obligation, and the `usize`
+    /// indicates exactly which predicate it is in the list of
+    /// instantiated predicates.
+    ExprItemObligation(DefId, rustc_hir::HirId, usize),
+
+    /// Combines `ExprItemObligation` and `BindingObligation`.
+    ExprBindingObligation(DefId, Span, rustc_hir::HirId, usize),
+
     /// A type like `&'a T` is WF only if `T: 'a`.
     ReferenceOutlivesReferent(Ty<'tcx>),
 
diff --git a/compiler/rustc_middle/src/ty/generics.rs b/compiler/rustc_middle/src/ty/generics.rs
index add2df25884e3..823e7f22af24d 100644
--- a/compiler/rustc_middle/src/ty/generics.rs
+++ b/compiler/rustc_middle/src/ty/generics.rs
@@ -122,6 +122,21 @@ pub struct Generics {
 }
 
 impl<'tcx> Generics {
+    /// Looks through the generics and all parents to find the index of the
+    /// given param def-id. This is in comparison to the `param_def_id_to_index`
+    /// struct member, which only stores information about this item's own
+    /// generics.
+    pub fn param_def_id_to_index(&self, tcx: TyCtxt<'tcx>, def_id: DefId) -> Option<u32> {
+        if let Some(idx) = self.param_def_id_to_index.get(&def_id) {
+            Some(*idx)
+        } else if let Some(parent) = self.parent {
+            let parent = tcx.generics_of(parent);
+            parent.param_def_id_to_index(tcx, def_id)
+        } else {
+            None
+        }
+    }
+
     #[inline]
     pub fn count(&self) -> usize {
         self.parent_count + self.params.len()
diff --git a/compiler/rustc_monomorphize/src/collector.rs b/compiler/rustc_monomorphize/src/collector.rs
index 96bbf5802e738..82ef16a7f72fc 100644
--- a/compiler/rustc_monomorphize/src/collector.rs
+++ b/compiler/rustc_monomorphize/src/collector.rs
@@ -128,7 +128,7 @@
 //! #### Unsizing Casts
 //! A subtle way of introducing neighbor edges is by casting to a trait object.
 //! Since the resulting fat-pointer contains a reference to a vtable, we need to
-//! instantiate all object-save methods of the trait, as we need to store
+//! instantiate all object-safe methods of the trait, as we need to store
 //! pointers to these functions even if they never get called anywhere. This can
 //! be seen as a special case of taking a function reference.
 //!
@@ -1044,10 +1044,12 @@ fn should_codegen_locally<'tcx>(tcx: TyCtxt<'tcx>, instance: &Instance<'tcx>) ->
 /// them.
 ///
 /// For example, the source type might be `&SomeStruct` and the target type
-/// might be `&SomeTrait` in a cast like:
+/// might be `&dyn SomeTrait` in a cast like:
 ///
+/// ```rust,ignore (not real code)
 /// let src: &SomeStruct = ...;
-/// let target = src as &SomeTrait;
+/// let target = src as &dyn SomeTrait;
+/// ```
 ///
 /// Then the output of this function would be (SomeStruct, SomeTrait) since for
 /// constructing the `target` fat-pointer we need the vtable for that pair.
@@ -1068,8 +1070,10 @@ fn should_codegen_locally<'tcx>(tcx: TyCtxt<'tcx>, instance: &Instance<'tcx>) ->
 /// for the pair of `T` (which is a trait) and the concrete type that `T` was
 /// originally coerced from:
 ///
+/// ```rust,ignore (not real code)
 /// let src: &ComplexStruct<SomeStruct> = ...;
-/// let target = src as &ComplexStruct<SomeTrait>;
+/// let target = src as &ComplexStruct<dyn SomeTrait>;
+/// ```
 ///
 /// Again, we want this `find_vtable_types_for_unsizing()` to provide the pair
 /// `(SomeStruct, SomeTrait)`.
diff --git a/compiler/rustc_parse/src/lib.rs b/compiler/rustc_parse/src/lib.rs
index 5924eba9f8b42..3691d82a835a9 100644
--- a/compiler/rustc_parse/src/lib.rs
+++ b/compiler/rustc_parse/src/lib.rs
@@ -62,7 +62,7 @@ pub fn parse_crate_from_file<'a>(input: &Path, sess: &'a ParseSess) -> PResult<'
 pub fn parse_crate_attrs_from_file<'a>(
     input: &Path,
     sess: &'a ParseSess,
-) -> PResult<'a, Vec<ast::Attribute>> {
+) -> PResult<'a, ast::AttrVec> {
     let mut parser = new_parser_from_file(sess, input, None);
     parser.parse_inner_attributes()
 }
@@ -79,7 +79,7 @@ pub fn parse_crate_attrs_from_source_str(
     name: FileName,
     source: String,
     sess: &ParseSess,
-) -> PResult<'_, Vec<ast::Attribute>> {
+) -> PResult<'_, ast::AttrVec> {
     new_parser_from_source_str(sess, name, source).parse_inner_attributes()
 }
 
diff --git a/compiler/rustc_parse/src/parser/attr.rs b/compiler/rustc_parse/src/parser/attr.rs
index acdbddf4099e6..72ab96b5ca670 100644
--- a/compiler/rustc_parse/src/parser/attr.rs
+++ b/compiler/rustc_parse/src/parser/attr.rs
@@ -34,7 +34,7 @@ enum OuterAttributeType {
 impl<'a> Parser<'a> {
     /// Parses attributes that appear before an item.
     pub(super) fn parse_outer_attributes(&mut self) -> PResult<'a, AttrWrapper> {
-        let mut outer_attrs: Vec<ast::Attribute> = Vec::new();
+        let mut outer_attrs = ast::AttrVec::new();
         let mut just_parsed_doc_comment = false;
         let start_pos = self.token_cursor.num_next_calls;
         loop {
@@ -106,7 +106,7 @@ impl<'a> Parser<'a> {
                 break;
             }
         }
-        Ok(AttrWrapper::new(outer_attrs.into(), start_pos))
+        Ok(AttrWrapper::new(outer_attrs, start_pos))
     }
 
     /// Matches `attribute = # ! [ meta_item ]`.
@@ -283,8 +283,8 @@ impl<'a> Parser<'a> {
     /// terminated by a semicolon.
     ///
     /// Matches `inner_attrs*`.
-    pub(crate) fn parse_inner_attributes(&mut self) -> PResult<'a, Vec<ast::Attribute>> {
-        let mut attrs: Vec<ast::Attribute> = vec![];
+    pub(crate) fn parse_inner_attributes(&mut self) -> PResult<'a, ast::AttrVec> {
+        let mut attrs = ast::AttrVec::new();
         loop {
             let start_pos: u32 = self.token_cursor.num_next_calls.try_into().unwrap();
             // Only try to parse if it is an inner attribute (has `!`).
diff --git a/compiler/rustc_parse/src/parser/attr_wrapper.rs b/compiler/rustc_parse/src/parser/attr_wrapper.rs
index 6c750ff428f53..ed54af9f53fb7 100644
--- a/compiler/rustc_parse/src/parser/attr_wrapper.rs
+++ b/compiler/rustc_parse/src/parser/attr_wrapper.rs
@@ -15,11 +15,11 @@ use std::ops::Range;
 /// for the attribute target. This allows us to perform cfg-expansion on
 /// a token stream before we invoke a derive proc-macro.
 ///
-/// This wrapper prevents direct access to the underlying `Vec<ast::Attribute>`.
+/// This wrapper prevents direct access to the underlying `ast::AttrVec>`.
 /// Parsing code can only get access to the underlying attributes
 /// by passing an `AttrWrapper` to `collect_tokens_trailing_tokens`.
 /// This makes it difficult to accidentally construct an AST node
-/// (which stores a `Vec<ast::Attribute>`) without first collecting tokens.
+/// (which stores an `ast::AttrVec`) without first collecting tokens.
 ///
 /// This struct has its own module, to ensure that the parser code
 /// cannot directly access the `attrs` field
@@ -49,9 +49,10 @@ impl AttrWrapper {
         self.attrs
     }
 
+    // Prepend `self.attrs` to `attrs`.
     // FIXME: require passing an NT to prevent misuse of this method
-    pub(crate) fn prepend_to_nt_inner(self, attrs: &mut Vec<Attribute>) {
-        let mut self_attrs: Vec<_> = self.attrs.into();
+    pub(crate) fn prepend_to_nt_inner(self, attrs: &mut AttrVec) {
+        let mut self_attrs = self.attrs.clone();
         std::mem::swap(attrs, &mut self_attrs);
         attrs.extend(self_attrs);
     }
@@ -196,7 +197,7 @@ impl<'a> Parser<'a> {
         &mut self,
         attrs: AttrWrapper,
         force_collect: ForceCollect,
-        f: impl FnOnce(&mut Self, Vec<ast::Attribute>) -> PResult<'a, (R, TrailingToken)>,
+        f: impl FnOnce(&mut Self, ast::AttrVec) -> PResult<'a, (R, TrailingToken)>,
     ) -> PResult<'a, R> {
         // We only bail out when nothing could possibly observe the collected tokens:
         // 1. We cannot be force collecting tokens (since force-collecting requires tokens
@@ -212,7 +213,7 @@ impl<'a> Parser<'a> {
             // or `#[cfg_attr]` attributes.
             && !self.capture_cfg
         {
-            return Ok(f(self, attrs.attrs.into())?.0);
+            return Ok(f(self, attrs.attrs)?.0);
         }
 
         let start_token = (self.token.clone(), self.token_spacing);
@@ -222,7 +223,7 @@ impl<'a> Parser<'a> {
         let prev_capturing = std::mem::replace(&mut self.capture_state.capturing, Capturing::Yes);
         let replace_ranges_start = self.capture_state.replace_ranges.len();
 
-        let ret = f(self, attrs.attrs.into());
+        let ret = f(self, attrs.attrs);
 
         self.capture_state.capturing = prev_capturing;
 
@@ -352,7 +353,7 @@ impl<'a> Parser<'a> {
         // on the captured token stream.
         if self.capture_cfg
             && matches!(self.capture_state.capturing, Capturing::Yes)
-            && has_cfg_or_cfg_attr(&final_attrs)
+            && has_cfg_or_cfg_attr(final_attrs)
         {
             let attr_data = AttributesData { attrs: final_attrs.to_vec().into(), tokens };
 
diff --git a/compiler/rustc_parse/src/parser/diagnostics.rs b/compiler/rustc_parse/src/parser/diagnostics.rs
index 744ec7e611402..d7facb29714bc 100644
--- a/compiler/rustc_parse/src/parser/diagnostics.rs
+++ b/compiler/rustc_parse/src/parser/diagnostics.rs
@@ -244,7 +244,7 @@ impl MultiSugg {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(parser::maybe_report_ambiguous_plus)]
+#[diag(parser::maybe_report_ambiguous_plus)]
 struct AmbiguousPlus {
     pub sum_ty: String,
     #[primary_span]
@@ -253,7 +253,7 @@ struct AmbiguousPlus {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(parser::maybe_recover_from_bad_type_plus, code = "E0178")]
+#[diag(parser::maybe_recover_from_bad_type_plus, code = "E0178")]
 struct BadTypePlus {
     pub ty: String,
     #[primary_span]
@@ -287,7 +287,7 @@ pub enum BadTypePlusSub {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(parser::maybe_recover_from_bad_qpath_stage_2)]
+#[diag(parser::maybe_recover_from_bad_qpath_stage_2)]
 struct BadQPathStage2 {
     #[primary_span]
     #[suggestion(applicability = "maybe-incorrect")]
@@ -296,7 +296,7 @@ struct BadQPathStage2 {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(parser::incorrect_semicolon)]
+#[diag(parser::incorrect_semicolon)]
 struct IncorrectSemicolon<'a> {
     #[primary_span]
     #[suggestion_short(applicability = "machine-applicable")]
@@ -307,7 +307,7 @@ struct IncorrectSemicolon<'a> {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(parser::incorrect_use_of_await)]
+#[diag(parser::incorrect_use_of_await)]
 struct IncorrectUseOfAwait {
     #[primary_span]
     #[suggestion(parser::parentheses_suggestion, applicability = "machine-applicable")]
@@ -315,7 +315,7 @@ struct IncorrectUseOfAwait {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(parser::incorrect_use_of_await)]
+#[diag(parser::incorrect_use_of_await)]
 struct IncorrectAwait {
     #[primary_span]
     span: Span,
@@ -326,7 +326,7 @@ struct IncorrectAwait {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(parser::in_in_typo)]
+#[diag(parser::in_in_typo)]
 struct InInTypo {
     #[primary_span]
     span: Span,
@@ -335,7 +335,7 @@ struct InInTypo {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(parser::invalid_variable_declaration)]
+#[diag(parser::invalid_variable_declaration)]
 pub struct InvalidVariableDeclaration {
     #[primary_span]
     pub span: Span,
@@ -2370,7 +2370,7 @@ impl<'a> Parser<'a> {
 
     fn recover_const_param_decl(&mut self, ty_generics: Option<&Generics>) -> Option<GenericArg> {
         let snapshot = self.create_snapshot_for_diagnostic();
-        let param = match self.parse_const_param(vec![]) {
+        let param = match self.parse_const_param(AttrVec::new()) {
             Ok(param) => param,
             Err(err) => {
                 err.cancel();
diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs
index df092f55bfae9..9fb9199231fb0 100644
--- a/compiler/rustc_parse/src/parser/expr.rs
+++ b/compiler/rustc_parse/src/parser/expr.rs
@@ -950,15 +950,15 @@ impl<'a> Parser<'a> {
         &mut self,
         e0: P<Expr>,
         lo: Span,
-        mut attrs: Vec<ast::Attribute>,
+        mut attrs: ast::AttrVec,
     ) -> PResult<'a, P<Expr>> {
         // Stitch the list of outer attributes onto the return value.
         // A little bit ugly, but the best way given the current code
         // structure
         self.parse_dot_or_call_expr_with_(e0, lo).map(|expr| {
             expr.map(|mut expr| {
-                attrs.extend::<Vec<_>>(expr.attrs.into());
-                expr.attrs = attrs.into();
+                attrs.extend(expr.attrs);
+                expr.attrs = attrs;
                 expr
             })
         })
@@ -2224,7 +2224,7 @@ impl<'a> Parser<'a> {
 
             Ok((
                 Param {
-                    attrs: attrs.into(),
+                    attrs,
                     ty,
                     pat,
                     span: lo.to(this.prev_token.span),
@@ -2732,7 +2732,7 @@ impl<'a> Parser<'a> {
                     let span = body.span;
                     return Ok((
                         ast::Arm {
-                            attrs: attrs.into(),
+                            attrs,
                             pat,
                             guard,
                             body,
@@ -2810,7 +2810,7 @@ impl<'a> Parser<'a> {
 
             Ok((
                 ast::Arm {
-                    attrs: attrs.into(),
+                    attrs,
                     pat,
                     guard,
                     body: expr,
@@ -3123,7 +3123,7 @@ impl<'a> Parser<'a> {
                     span: lo.to(expr.span),
                     expr,
                     is_shorthand,
-                    attrs: attrs.into(),
+                    attrs,
                     id: DUMMY_NODE_ID,
                     is_placeholder: false,
                 },
@@ -3219,14 +3219,10 @@ impl<'a> Parser<'a> {
         await_expr
     }
 
-    pub(crate) fn mk_expr_with_attrs<A>(&self, span: Span, kind: ExprKind, attrs: A) -> P<Expr>
-    where
-        A: Into<AttrVec>,
-    {
-        P(Expr { kind, span, attrs: attrs.into(), id: DUMMY_NODE_ID, tokens: None })
+    pub(crate) fn mk_expr_with_attrs(&self, span: Span, kind: ExprKind, attrs: AttrVec) -> P<Expr> {
+        P(Expr { kind, span, attrs, id: DUMMY_NODE_ID, tokens: None })
     }
 
-    // njn: rename
     pub(crate) fn mk_expr(&self, span: Span, kind: ExprKind) -> P<Expr> {
         P(Expr { kind, span, attrs: AttrVec::new(), id: DUMMY_NODE_ID, tokens: None })
     }
@@ -3248,7 +3244,7 @@ impl<'a> Parser<'a> {
     fn collect_tokens_for_expr(
         &mut self,
         attrs: AttrWrapper,
-        f: impl FnOnce(&mut Self, Vec<ast::Attribute>) -> PResult<'a, P<Expr>>,
+        f: impl FnOnce(&mut Self, ast::AttrVec) -> PResult<'a, P<Expr>>,
     ) -> PResult<'a, P<Expr>> {
         self.collect_tokens_trailing_token(attrs, ForceCollect::No, |this, attrs| {
             let res = f(this, attrs)?;
diff --git a/compiler/rustc_parse/src/parser/generics.rs b/compiler/rustc_parse/src/parser/generics.rs
index 5e5f2fd7d9f8d..4d0a8b05eb027 100644
--- a/compiler/rustc_parse/src/parser/generics.rs
+++ b/compiler/rustc_parse/src/parser/generics.rs
@@ -1,9 +1,7 @@
 use super::{ForceCollect, Parser, TrailingToken};
 
 use rustc_ast::token;
-use rustc_ast::{
-    self as ast, Attribute, GenericBounds, GenericParam, GenericParamKind, WhereClause,
-};
+use rustc_ast::{self as ast, AttrVec, GenericBounds, GenericParam, GenericParamKind, WhereClause};
 use rustc_errors::{Applicability, PResult};
 use rustc_span::symbol::kw;
 
@@ -26,7 +24,7 @@ impl<'a> Parser<'a> {
     }
 
     /// Matches `typaram = IDENT (`?` unbound)? optbounds ( EQ ty )?`.
-    fn parse_ty_param(&mut self, preceding_attrs: Vec<Attribute>) -> PResult<'a, GenericParam> {
+    fn parse_ty_param(&mut self, preceding_attrs: AttrVec) -> PResult<'a, GenericParam> {
         let ident = self.parse_ident()?;
 
         // Parse optional colon and param bounds.
@@ -43,7 +41,7 @@ impl<'a> Parser<'a> {
         Ok(GenericParam {
             ident,
             id: ast::DUMMY_NODE_ID,
-            attrs: preceding_attrs.into(),
+            attrs: preceding_attrs,
             bounds,
             kind: GenericParamKind::Type { default },
             is_placeholder: false,
@@ -53,7 +51,7 @@ impl<'a> Parser<'a> {
 
     pub(crate) fn parse_const_param(
         &mut self,
-        preceding_attrs: Vec<Attribute>,
+        preceding_attrs: AttrVec,
     ) -> PResult<'a, GenericParam> {
         let const_span = self.token.span;
 
@@ -68,7 +66,7 @@ impl<'a> Parser<'a> {
         Ok(GenericParam {
             ident,
             id: ast::DUMMY_NODE_ID,
-            attrs: preceding_attrs.into(),
+            attrs: preceding_attrs,
             bounds: Vec::new(),
             kind: GenericParamKind::Const { ty, kw_span: const_span, default },
             is_placeholder: false,
@@ -109,7 +107,7 @@ impl<'a> Parser<'a> {
                         Some(ast::GenericParam {
                             ident: lifetime.ident,
                             id: lifetime.id,
-                            attrs: attrs.into(),
+                            attrs,
                             bounds,
                             kind: ast::GenericParamKind::Lifetime,
                             is_placeholder: false,
diff --git a/compiler/rustc_parse/src/parser/item.rs b/compiler/rustc_parse/src/parser/item.rs
index cd3c982ce817c..b743162a7e4d0 100644
--- a/compiler/rustc_parse/src/parser/item.rs
+++ b/compiler/rustc_parse/src/parser/item.rs
@@ -32,7 +32,7 @@ impl<'a> Parser<'a> {
     }
 
     /// Parses a `mod <foo> { ... }` or `mod <foo>;` item.
-    fn parse_item_mod(&mut self, attrs: &mut Vec<Attribute>) -> PResult<'a, ItemInfo> {
+    fn parse_item_mod(&mut self, attrs: &mut AttrVec) -> PResult<'a, ItemInfo> {
         let unsafety = self.parse_unsafety();
         self.expect_keyword(kw::Mod)?;
         let id = self.parse_ident()?;
@@ -40,9 +40,9 @@ impl<'a> Parser<'a> {
             ModKind::Unloaded
         } else {
             self.expect(&token::OpenDelim(Delimiter::Brace))?;
-            let (mut inner_attrs, items, inner_span) =
+            let (inner_attrs, items, inner_span) =
                 self.parse_mod(&token::CloseDelim(Delimiter::Brace))?;
-            attrs.append(&mut inner_attrs);
+            attrs.extend(inner_attrs);
             ModKind::Loaded(items, Inline::Yes, inner_span)
         };
         Ok((id, ItemKind::Mod(unsafety, mod_kind)))
@@ -52,7 +52,7 @@ impl<'a> Parser<'a> {
     pub fn parse_mod(
         &mut self,
         term: &TokenKind,
-    ) -> PResult<'a, (Vec<Attribute>, Vec<P<Item>>, ModSpans)> {
+    ) -> PResult<'a, (AttrVec, Vec<P<Item>>, ModSpans)> {
         let lo = self.token.span;
         let attrs = self.parse_inner_attributes()?;
 
@@ -134,7 +134,7 @@ impl<'a> Parser<'a> {
 
     fn parse_item_common_(
         &mut self,
-        mut attrs: Vec<Attribute>,
+        mut attrs: AttrVec,
         mac_allowed: bool,
         attrs_allowed: bool,
         fn_parse_mode: FnParseMode,
@@ -198,7 +198,7 @@ impl<'a> Parser<'a> {
     /// Parses one of the items allowed by the flags.
     fn parse_item_kind(
         &mut self,
-        attrs: &mut Vec<Attribute>,
+        attrs: &mut AttrVec,
         macros_allowed: bool,
         lo: Span,
         vis: &Visibility,
@@ -534,7 +534,7 @@ impl<'a> Parser<'a> {
     /// ```
     fn parse_item_impl(
         &mut self,
-        attrs: &mut Vec<Attribute>,
+        attrs: &mut AttrVec,
         defaultness: Defaultness,
     ) -> PResult<'a, ItemInfo> {
         let unsafety = self.parse_unsafety();
@@ -661,12 +661,12 @@ impl<'a> Parser<'a> {
 
     fn parse_item_list<T>(
         &mut self,
-        attrs: &mut Vec<Attribute>,
+        attrs: &mut AttrVec,
         mut parse_item: impl FnMut(&mut Parser<'a>) -> PResult<'a, Option<Option<T>>>,
     ) -> PResult<'a, Vec<T>> {
         let open_brace_span = self.token.span;
         self.expect(&token::OpenDelim(Delimiter::Brace))?;
-        attrs.append(&mut self.parse_inner_attributes()?);
+        attrs.extend(self.parse_inner_attributes()?);
 
         let mut items = Vec::new();
         while !self.eat(&token::CloseDelim(Delimiter::Brace)) {
@@ -775,7 +775,7 @@ impl<'a> Parser<'a> {
     }
 
     /// Parses `unsafe? auto? trait Foo { ... }` or `trait Foo = Bar;`.
-    fn parse_item_trait(&mut self, attrs: &mut Vec<Attribute>, lo: Span) -> PResult<'a, ItemInfo> {
+    fn parse_item_trait(&mut self, attrs: &mut AttrVec, lo: Span) -> PResult<'a, ItemInfo> {
         let unsafety = self.parse_unsafety();
         // Parse optional `auto` prefix.
         let is_auto = if self.eat_keyword(kw::Auto) { IsAuto::Yes } else { IsAuto::No };
@@ -1061,7 +1061,7 @@ impl<'a> Parser<'a> {
     /// ```
     fn parse_item_foreign_mod(
         &mut self,
-        attrs: &mut Vec<Attribute>,
+        attrs: &mut AttrVec,
         mut unsafety: Unsafe,
     ) -> PResult<'a, ItemInfo> {
         let abi = self.parse_abi(); // ABI?
@@ -1179,7 +1179,7 @@ impl<'a> Parser<'a> {
     fn recover_const_impl(
         &mut self,
         const_span: Span,
-        attrs: &mut Vec<Attribute>,
+        attrs: &mut AttrVec,
         defaultness: Defaultness,
     ) -> PResult<'a, ItemInfo> {
         let impl_span = self.token.span;
@@ -1337,7 +1337,7 @@ impl<'a> Parser<'a> {
                     ident,
                     vis,
                     id: DUMMY_NODE_ID,
-                    attrs: variant_attrs.into(),
+                    attrs: variant_attrs,
                     data: struct_def,
                     disr_expr,
                     span: vlo.to(this.prev_token.span),
@@ -1494,7 +1494,7 @@ impl<'a> Parser<'a> {
                         ident: None,
                         id: DUMMY_NODE_ID,
                         ty,
-                        attrs: attrs.into(),
+                        attrs,
                         is_placeholder: false,
                     },
                     TrailingToken::MaybeComma,
@@ -1520,7 +1520,7 @@ impl<'a> Parser<'a> {
         adt_ty: &str,
         lo: Span,
         vis: Visibility,
-        attrs: Vec<Attribute>,
+        attrs: AttrVec,
     ) -> PResult<'a, FieldDef> {
         let mut seen_comma: bool = false;
         let a_var = self.parse_name_and_ty(adt_ty, lo, vis, attrs)?;
@@ -1650,7 +1650,7 @@ impl<'a> Parser<'a> {
         adt_ty: &str,
         lo: Span,
         vis: Visibility,
-        attrs: Vec<Attribute>,
+        attrs: AttrVec,
     ) -> PResult<'a, FieldDef> {
         let name = self.parse_field_ident(adt_ty, lo)?;
         self.expect_field_ty_separator()?;
@@ -1684,7 +1684,7 @@ impl<'a> Parser<'a> {
             vis,
             id: DUMMY_NODE_ID,
             ty,
-            attrs: attrs.into(),
+            attrs,
             is_placeholder: false,
         })
     }
@@ -1703,7 +1703,7 @@ impl<'a> Parser<'a> {
                 // We use `parse_fn` to get a span for the function
                 let fn_parse_mode = FnParseMode { req_name: |_| true, req_body: true };
                 if let Err(mut db) =
-                    self.parse_fn(&mut Vec::new(), fn_parse_mode, lo, &inherited_vis)
+                    self.parse_fn(&mut AttrVec::new(), fn_parse_mode, lo, &inherited_vis)
                 {
                     db.delay_as_bug();
                 }
@@ -1979,7 +1979,7 @@ impl<'a> Parser<'a> {
     /// Parse a function starting from the front matter (`const ...`) to the body `{ ... }` or `;`.
     fn parse_fn(
         &mut self,
-        attrs: &mut Vec<Attribute>,
+        attrs: &mut AttrVec,
         fn_parse_mode: FnParseMode,
         sig_lo: Span,
         vis: &Visibility,
@@ -2002,7 +2002,7 @@ impl<'a> Parser<'a> {
     /// or e.g. a block when the function is a provided one.
     fn parse_fn_body(
         &mut self,
-        attrs: &mut Vec<Attribute>,
+        attrs: &mut AttrVec,
         ident: &Ident,
         sig_hi: &mut Span,
         req_body: bool,
@@ -2017,7 +2017,7 @@ impl<'a> Parser<'a> {
             // Include the trailing semicolon in the span of the signature
             self.expect_semi()?;
             *sig_hi = self.prev_token.span;
-            (Vec::new(), None)
+            (AttrVec::new(), None)
         } else if self.check(&token::OpenDelim(Delimiter::Brace)) || self.token.is_whole_block() {
             self.parse_inner_attrs_and_block().map(|(attrs, body)| (attrs, Some(body)))?
         } else if self.token.kind == token::Eq {
@@ -2034,7 +2034,7 @@ impl<'a> Parser<'a> {
                     Applicability::MachineApplicable,
                 )
                 .emit();
-            (Vec::new(), Some(self.mk_block_err(span)))
+            (AttrVec::new(), Some(self.mk_block_err(span)))
         } else {
             let expected = if req_body {
                 &[token::OpenDelim(Delimiter::Brace)][..]
@@ -2051,7 +2051,7 @@ impl<'a> Parser<'a> {
                     return Err(err);
                 }
             }
-            (Vec::new(), None)
+            (AttrVec::new(), None)
         };
         attrs.extend(inner_attrs);
         Ok(body)
@@ -2280,7 +2280,7 @@ impl<'a> Parser<'a> {
         self.collect_tokens_trailing_token(attrs, ForceCollect::No, |this, attrs| {
             // Possibly parse `self`. Recover if we parsed it and it wasn't allowed here.
             if let Some(mut param) = this.parse_self_param()? {
-                param.attrs = attrs.into();
+                param.attrs = attrs;
                 let res = if first_param { Ok(param) } else { this.recover_bad_self_param(param) };
                 return Ok((res?, TrailingToken::None));
             }
@@ -2341,14 +2341,7 @@ impl<'a> Parser<'a> {
             let span = lo.to(this.prev_token.span);
 
             Ok((
-                Param {
-                    attrs: attrs.into(),
-                    id: ast::DUMMY_NODE_ID,
-                    is_placeholder: false,
-                    pat,
-                    span,
-                    ty,
-                },
+                Param { attrs, id: ast::DUMMY_NODE_ID, is_placeholder: false, pat, span, ty },
                 TrailingToken::None,
             ))
         })
diff --git a/compiler/rustc_parse/src/parser/pat.rs b/compiler/rustc_parse/src/parser/pat.rs
index 42bf889844710..8b3200d45fccd 100644
--- a/compiler/rustc_parse/src/parser/pat.rs
+++ b/compiler/rustc_parse/src/parser/pat.rs
@@ -4,8 +4,8 @@ use rustc_ast::mut_visit::{noop_visit_pat, MutVisitor};
 use rustc_ast::ptr::P;
 use rustc_ast::token::{self, Delimiter};
 use rustc_ast::{
-    self as ast, Attribute, BindingMode, Expr, ExprKind, MacCall, Mutability, Pat, PatField,
-    PatKind, Path, QSelf, RangeEnd, RangeSyntax,
+    self as ast, AttrVec, BindingMode, Expr, ExprKind, MacCall, Mutability, Pat, PatField, PatKind,
+    Path, QSelf, RangeEnd, RangeSyntax,
 };
 use rustc_ast_pretty::pprust;
 use rustc_errors::{struct_span_err, Applicability, DiagnosticBuilder, ErrorGuaranteed, PResult};
@@ -1093,7 +1093,7 @@ impl<'a> Parser<'a> {
             .emit();
     }
 
-    fn parse_pat_field(&mut self, lo: Span, attrs: Vec<Attribute>) -> PResult<'a, PatField> {
+    fn parse_pat_field(&mut self, lo: Span, attrs: AttrVec) -> PResult<'a, PatField> {
         // Check if a colon exists one ahead. This means we're parsing a fieldname.
         let hi;
         let (subpat, fieldname, is_shorthand) = if self.look_ahead(1, |t| t == &token::Colon) {
@@ -1134,7 +1134,7 @@ impl<'a> Parser<'a> {
             ident: fieldname,
             pat: subpat,
             is_shorthand,
-            attrs: attrs.into(),
+            attrs,
             id: ast::DUMMY_NODE_ID,
             span: lo.to(hi),
             is_placeholder: false,
diff --git a/compiler/rustc_parse/src/parser/stmt.rs b/compiler/rustc_parse/src/parser/stmt.rs
index 12b1a37e02247..3d957406b19d8 100644
--- a/compiler/rustc_parse/src/parser/stmt.rs
+++ b/compiler/rustc_parse/src/parser/stmt.rs
@@ -130,7 +130,7 @@ impl<'a> Parser<'a> {
             let path = this.parse_path(PathStyle::Expr)?;
 
             if this.eat(&token::Not) {
-                let stmt_mac = this.parse_stmt_mac(lo, attrs.into(), path)?;
+                let stmt_mac = this.parse_stmt_mac(lo, attrs, path)?;
                 if this.token == token::Semi {
                     return Ok((stmt_mac, TrailingToken::Semi));
                 } else {
@@ -190,7 +190,7 @@ impl<'a> Parser<'a> {
             // Since none of the above applied, this is an expression statement macro.
             let e = self.mk_expr(lo.to(hi), ExprKind::MacCall(mac));
             let e = self.maybe_recover_from_bad_qpath(e)?;
-            let e = self.parse_dot_or_call_expr_with(e, lo, attrs.into())?;
+            let e = self.parse_dot_or_call_expr_with(e, lo, attrs)?;
             let e = self.parse_assoc_expr_with(0, LhsExpr::AlreadyParsed(e))?;
             StmtKind::Expr(e)
         };
@@ -229,7 +229,7 @@ impl<'a> Parser<'a> {
     ) -> PResult<'a, Stmt> {
         self.collect_tokens_trailing_token(attrs, force_collect, |this, attrs| {
             this.expect_keyword(kw::Let)?;
-            let local = this.parse_local(attrs.into())?;
+            let local = this.parse_local(attrs)?;
             let trailing = if capture_semi && this.token.kind == token::Semi {
                 TrailingToken::Semi
             } else {
@@ -241,7 +241,7 @@ impl<'a> Parser<'a> {
 
     fn recover_local_after_let(&mut self, lo: Span, attrs: AttrWrapper) -> PResult<'a, Stmt> {
         self.collect_tokens_trailing_token(attrs, ForceCollect::No, |this, attrs| {
-            let local = this.parse_local(attrs.into())?;
+            let local = this.parse_local(attrs)?;
             // FIXME - maybe capture semicolon in recovery?
             Ok((
                 this.mk_stmt(lo.to(this.prev_token.span), StmtKind::Local(local)),
@@ -509,9 +509,7 @@ impl<'a> Parser<'a> {
     }
 
     /// Parses a block. Inner attributes are allowed.
-    pub(super) fn parse_inner_attrs_and_block(
-        &mut self,
-    ) -> PResult<'a, (Vec<Attribute>, P<Block>)> {
+    pub(super) fn parse_inner_attrs_and_block(&mut self) -> PResult<'a, (AttrVec, P<Block>)> {
         self.parse_block_common(self.token.span, BlockCheckMode::Default)
     }
 
@@ -520,8 +518,8 @@ impl<'a> Parser<'a> {
         &mut self,
         lo: Span,
         blk_mode: BlockCheckMode,
-    ) -> PResult<'a, (Vec<Attribute>, P<Block>)> {
-        maybe_whole!(self, NtBlock, |x| (Vec::new(), x));
+    ) -> PResult<'a, (AttrVec, P<Block>)> {
+        maybe_whole!(self, NtBlock, |x| (AttrVec::new(), x));
 
         self.maybe_recover_unexpected_block_label();
         if !self.eat(&token::OpenDelim(Delimiter::Brace)) {
diff --git a/compiler/rustc_passes/src/errors.rs b/compiler/rustc_passes/src/errors.rs
index cd465380867cf..383982013d9e7 100644
--- a/compiler/rustc_passes/src/errors.rs
+++ b/compiler/rustc_passes/src/errors.rs
@@ -3,37 +3,37 @@ use rustc_macros::{LintDiagnostic, SessionDiagnostic, SessionSubdiagnostic};
 use rustc_span::{Span, Symbol};
 
 #[derive(LintDiagnostic)]
-#[lint(passes::outer_crate_level_attr)]
+#[diag(passes::outer_crate_level_attr)]
 pub struct OuterCrateLevelAttr;
 
 #[derive(LintDiagnostic)]
-#[lint(passes::inner_crate_level_attr)]
+#[diag(passes::inner_crate_level_attr)]
 pub struct InnerCrateLevelAttr;
 
 #[derive(LintDiagnostic)]
-#[lint(passes::ignored_attr_with_macro)]
+#[diag(passes::ignored_attr_with_macro)]
 pub struct IgnoredAttrWithMacro<'a> {
     pub sym: &'a str,
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::ignored_attr)]
+#[diag(passes::ignored_attr)]
 pub struct IgnoredAttr<'a> {
     pub sym: &'a str,
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::inline_ignored_function_prototype)]
+#[diag(passes::inline_ignored_function_prototype)]
 pub struct IgnoredInlineAttrFnProto;
 
 #[derive(LintDiagnostic)]
-#[lint(passes::inline_ignored_constants)]
+#[diag(passes::inline_ignored_constants)]
 #[warn_]
 #[note]
 pub struct IgnoredInlineAttrConstants;
 
 #[derive(SessionDiagnostic)]
-#[error(passes::inline_not_fn_or_closure, code = "E0518")]
+#[diag(passes::inline_not_fn_or_closure, code = "E0518")]
 pub struct InlineNotFnOrClosure {
     #[primary_span]
     pub attr_span: Span,
@@ -42,19 +42,19 @@ pub struct InlineNotFnOrClosure {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::no_coverage_ignored_function_prototype)]
+#[diag(passes::no_coverage_ignored_function_prototype)]
 pub struct IgnoredNoCoverageFnProto;
 
 #[derive(LintDiagnostic)]
-#[lint(passes::no_coverage_propagate)]
+#[diag(passes::no_coverage_propagate)]
 pub struct IgnoredNoCoveragePropagate;
 
 #[derive(LintDiagnostic)]
-#[lint(passes::no_coverage_fn_defn)]
+#[diag(passes::no_coverage_fn_defn)]
 pub struct IgnoredNoCoverageFnDefn;
 
 #[derive(SessionDiagnostic)]
-#[error(passes::no_coverage_not_coverable, code = "E0788")]
+#[diag(passes::no_coverage_not_coverable, code = "E0788")]
 pub struct IgnoredNoCoverageNotCoverable {
     #[primary_span]
     pub attr_span: Span,
@@ -63,7 +63,7 @@ pub struct IgnoredNoCoverageNotCoverable {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::should_be_applied_to_fn)]
+#[diag(passes::should_be_applied_to_fn)]
 pub struct AttrShouldBeAppliedToFn {
     #[primary_span]
     pub attr_span: Span,
@@ -72,14 +72,14 @@ pub struct AttrShouldBeAppliedToFn {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::naked_tracked_caller, code = "E0736")]
+#[diag(passes::naked_tracked_caller, code = "E0736")]
 pub struct NakedTrackedCaller {
     #[primary_span]
     pub attr_span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::should_be_applied_to_fn, code = "E0739")]
+#[diag(passes::should_be_applied_to_fn, code = "E0739")]
 pub struct TrackedCallerWrongLocation {
     #[primary_span]
     pub attr_span: Span,
@@ -88,7 +88,7 @@ pub struct TrackedCallerWrongLocation {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::should_be_applied_to_struct_enum, code = "E0701")]
+#[diag(passes::should_be_applied_to_struct_enum, code = "E0701")]
 pub struct NonExhaustiveWrongLocation {
     #[primary_span]
     pub attr_span: Span,
@@ -97,7 +97,7 @@ pub struct NonExhaustiveWrongLocation {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::should_be_applied_to_trait)]
+#[diag(passes::should_be_applied_to_trait)]
 pub struct AttrShouldBeAppliedToTrait {
     #[primary_span]
     pub attr_span: Span,
@@ -106,11 +106,11 @@ pub struct AttrShouldBeAppliedToTrait {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::target_feature_on_statement)]
+#[diag(passes::target_feature_on_statement)]
 pub struct TargetFeatureOnStatement;
 
 #[derive(SessionDiagnostic)]
-#[error(passes::should_be_applied_to_static)]
+#[diag(passes::should_be_applied_to_static)]
 pub struct AttrShouldBeAppliedToStatic {
     #[primary_span]
     pub attr_span: Span,
@@ -119,7 +119,7 @@ pub struct AttrShouldBeAppliedToStatic {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_expect_str)]
+#[diag(passes::doc_expect_str)]
 pub struct DocExpectStr<'a> {
     #[primary_span]
     pub attr_span: Span,
@@ -127,7 +127,7 @@ pub struct DocExpectStr<'a> {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_alias_empty)]
+#[diag(passes::doc_alias_empty)]
 pub struct DocAliasEmpty<'a> {
     #[primary_span]
     pub span: Span,
@@ -135,7 +135,7 @@ pub struct DocAliasEmpty<'a> {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_alias_bad_char)]
+#[diag(passes::doc_alias_bad_char)]
 pub struct DocAliasBadChar<'a> {
     #[primary_span]
     pub span: Span,
@@ -144,7 +144,7 @@ pub struct DocAliasBadChar<'a> {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_alias_start_end)]
+#[diag(passes::doc_alias_start_end)]
 pub struct DocAliasStartEnd<'a> {
     #[primary_span]
     pub span: Span,
@@ -152,7 +152,7 @@ pub struct DocAliasStartEnd<'a> {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_alias_bad_location)]
+#[diag(passes::doc_alias_bad_location)]
 pub struct DocAliasBadLocation<'a> {
     #[primary_span]
     pub span: Span,
@@ -161,7 +161,7 @@ pub struct DocAliasBadLocation<'a> {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_alias_not_an_alias)]
+#[diag(passes::doc_alias_not_an_alias)]
 pub struct DocAliasNotAnAlias<'a> {
     #[primary_span]
     pub span: Span,
@@ -169,42 +169,42 @@ pub struct DocAliasNotAnAlias<'a> {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::doc_alias_duplicated)]
+#[diag(passes::doc_alias_duplicated)]
 pub struct DocAliasDuplicated {
     #[label]
     pub first_defn: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_alias_not_string_literal)]
+#[diag(passes::doc_alias_not_string_literal)]
 pub struct DocAliasNotStringLiteral {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_alias_malformed)]
+#[diag(passes::doc_alias_malformed)]
 pub struct DocAliasMalformed {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_keyword_empty_mod)]
+#[diag(passes::doc_keyword_empty_mod)]
 pub struct DocKeywordEmptyMod {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_keyword_not_mod)]
+#[diag(passes::doc_keyword_not_mod)]
 pub struct DocKeywordNotMod {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_keyword_invalid_ident)]
+#[diag(passes::doc_keyword_invalid_ident)]
 pub struct DocKeywordInvalidIdent {
     #[primary_span]
     pub span: Span,
@@ -212,21 +212,21 @@ pub struct DocKeywordInvalidIdent {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_fake_variadic_not_valid)]
+#[diag(passes::doc_fake_variadic_not_valid)]
 pub struct DocFakeVariadicNotValid {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_keyword_only_impl)]
+#[diag(passes::doc_keyword_only_impl)]
 pub struct DocKeywordOnlyImpl {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_inline_conflict)]
+#[diag(passes::doc_inline_conflict)]
 #[help]
 pub struct DocKeywordConflict {
     #[primary_span]
@@ -234,7 +234,7 @@ pub struct DocKeywordConflict {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::doc_inline_only_use)]
+#[diag(passes::doc_inline_only_use)]
 #[note]
 pub struct DocInlineOnlyUse {
     #[label]
@@ -244,7 +244,7 @@ pub struct DocInlineOnlyUse {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_attr_not_crate_level)]
+#[diag(passes::doc_attr_not_crate_level)]
 pub struct DocAttrNotCrateLevel<'a> {
     #[primary_span]
     pub span: Span,
@@ -252,27 +252,27 @@ pub struct DocAttrNotCrateLevel<'a> {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::doc_test_unknown)]
+#[diag(passes::doc_test_unknown)]
 pub struct DocTestUnknown {
     pub path: String,
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::doc_test_takes_list)]
+#[diag(passes::doc_test_takes_list)]
 pub struct DocTestTakesList;
 
 #[derive(LintDiagnostic)]
-#[lint(passes::doc_primitive)]
+#[diag(passes::doc_primitive)]
 pub struct DocPrimitive;
 
 #[derive(LintDiagnostic)]
-#[lint(passes::doc_test_unknown_any)]
+#[diag(passes::doc_test_unknown_any)]
 pub struct DocTestUnknownAny {
     pub path: String,
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::doc_test_unknown_spotlight)]
+#[diag(passes::doc_test_unknown_spotlight)]
 #[note]
 #[note(passes::no_op_note)]
 pub struct DocTestUnknownSpotlight {
@@ -282,7 +282,7 @@ pub struct DocTestUnknownSpotlight {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::doc_test_unknown_include)]
+#[diag(passes::doc_test_unknown_include)]
 pub struct DocTestUnknownInclude {
     pub path: String,
     pub value: String,
@@ -292,11 +292,11 @@ pub struct DocTestUnknownInclude {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::doc_invalid)]
+#[diag(passes::doc_invalid)]
 pub struct DocInvalid;
 
 #[derive(SessionDiagnostic)]
-#[error(passes::pass_by_value)]
+#[diag(passes::pass_by_value)]
 pub struct PassByValue {
     #[primary_span]
     pub attr_span: Span,
@@ -305,7 +305,7 @@ pub struct PassByValue {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::allow_incoherent_impl)]
+#[diag(passes::allow_incoherent_impl)]
 pub struct AllowIncoherentImpl {
     #[primary_span]
     pub attr_span: Span,
@@ -314,7 +314,7 @@ pub struct AllowIncoherentImpl {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::has_incoherent_inherent_impl)]
+#[diag(passes::has_incoherent_inherent_impl)]
 pub struct HasIncoherentInherentImpl {
     #[primary_span]
     pub attr_span: Span,
@@ -323,21 +323,21 @@ pub struct HasIncoherentInherentImpl {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::must_use_async)]
+#[diag(passes::must_use_async)]
 pub struct MustUseAsync {
     #[label]
     pub span: Span,
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::must_use_no_effect)]
+#[diag(passes::must_use_no_effect)]
 pub struct MustUseNoEffect {
     pub article: &'static str,
     pub target: rustc_hir::Target,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::must_not_suspend)]
+#[diag(passes::must_not_suspend)]
 pub struct MustNotSuspend {
     #[primary_span]
     pub attr_span: Span,
@@ -346,7 +346,7 @@ pub struct MustNotSuspend {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::cold)]
+#[diag(passes::cold)]
 #[warn_]
 pub struct Cold {
     #[label]
@@ -354,7 +354,7 @@ pub struct Cold {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::link)]
+#[diag(passes::link)]
 #[warn_]
 pub struct Link {
     #[label]
@@ -362,7 +362,7 @@ pub struct Link {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::link_name)]
+#[diag(passes::link_name)]
 #[warn_]
 pub struct LinkName<'a> {
     #[help]
@@ -373,7 +373,7 @@ pub struct LinkName<'a> {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::no_link)]
+#[diag(passes::no_link)]
 pub struct NoLink {
     #[primary_span]
     pub attr_span: Span,
@@ -382,7 +382,7 @@ pub struct NoLink {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::export_name)]
+#[diag(passes::export_name)]
 pub struct ExportName {
     #[primary_span]
     pub attr_span: Span,
@@ -391,7 +391,7 @@ pub struct ExportName {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::rustc_layout_scalar_valid_range_not_struct)]
+#[diag(passes::rustc_layout_scalar_valid_range_not_struct)]
 pub struct RustcLayoutScalarValidRangeNotStruct {
     #[primary_span]
     pub attr_span: Span,
@@ -400,14 +400,14 @@ pub struct RustcLayoutScalarValidRangeNotStruct {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::rustc_layout_scalar_valid_range_arg)]
+#[diag(passes::rustc_layout_scalar_valid_range_arg)]
 pub struct RustcLayoutScalarValidRangeArg {
     #[primary_span]
     pub attr_span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::rustc_legacy_const_generics_only)]
+#[diag(passes::rustc_legacy_const_generics_only)]
 pub struct RustcLegacyConstGenericsOnly {
     #[primary_span]
     pub attr_span: Span,
@@ -416,7 +416,7 @@ pub struct RustcLegacyConstGenericsOnly {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::rustc_legacy_const_generics_index)]
+#[diag(passes::rustc_legacy_const_generics_index)]
 pub struct RustcLegacyConstGenericsIndex {
     #[primary_span]
     pub attr_span: Span,
@@ -425,7 +425,7 @@ pub struct RustcLegacyConstGenericsIndex {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::rustc_legacy_const_generics_index_exceed)]
+#[diag(passes::rustc_legacy_const_generics_index_exceed)]
 pub struct RustcLegacyConstGenericsIndexExceed {
     #[primary_span]
     #[label]
@@ -434,21 +434,21 @@ pub struct RustcLegacyConstGenericsIndexExceed {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::rustc_legacy_const_generics_index_negative)]
+#[diag(passes::rustc_legacy_const_generics_index_negative)]
 pub struct RustcLegacyConstGenericsIndexNegative {
     #[primary_span]
     pub invalid_args: Vec<Span>,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::rustc_dirty_clean)]
+#[diag(passes::rustc_dirty_clean)]
 pub struct RustcDirtyClean {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::link_section)]
+#[diag(passes::link_section)]
 #[warn_]
 pub struct LinkSection {
     #[label]
@@ -456,7 +456,7 @@ pub struct LinkSection {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::no_mangle_foreign)]
+#[diag(passes::no_mangle_foreign)]
 #[warn_]
 #[note]
 pub struct NoMangleForeign {
@@ -468,7 +468,7 @@ pub struct NoMangleForeign {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::no_mangle)]
+#[diag(passes::no_mangle)]
 #[warn_]
 pub struct NoMangle {
     #[label]
@@ -476,32 +476,32 @@ pub struct NoMangle {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::repr_ident, code = "E0565")]
+#[diag(passes::repr_ident, code = "E0565")]
 pub struct ReprIdent {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::repr_conflicting, code = "E0566")]
+#[diag(passes::repr_conflicting, code = "E0566")]
 pub struct ReprConflicting;
 
 #[derive(SessionDiagnostic)]
-#[error(passes::used_static)]
+#[diag(passes::used_static)]
 pub struct UsedStatic {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::used_compiler_linker)]
+#[diag(passes::used_compiler_linker)]
 pub struct UsedCompilerLinker {
     #[primary_span]
     pub spans: Vec<Span>,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::allow_internal_unstable)]
+#[diag(passes::allow_internal_unstable)]
 pub struct AllowInternalUnstable {
     #[primary_span]
     pub attr_span: Span,
@@ -510,14 +510,14 @@ pub struct AllowInternalUnstable {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::debug_visualizer_placement)]
+#[diag(passes::debug_visualizer_placement)]
 pub struct DebugVisualizerPlacement {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::debug_visualizer_invalid)]
+#[diag(passes::debug_visualizer_invalid)]
 #[note(passes::note_1)]
 #[note(passes::note_2)]
 #[note(passes::note_3)]
@@ -527,7 +527,7 @@ pub struct DebugVisualizerInvalid {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::rustc_allow_const_fn_unstable)]
+#[diag(passes::rustc_allow_const_fn_unstable)]
 pub struct RustcAllowConstFnUnstable {
     #[primary_span]
     pub attr_span: Span,
@@ -536,7 +536,7 @@ pub struct RustcAllowConstFnUnstable {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::rustc_std_internal_symbol)]
+#[diag(passes::rustc_std_internal_symbol)]
 pub struct RustcStdInternalSymbol {
     #[primary_span]
     pub attr_span: Span,
@@ -545,42 +545,42 @@ pub struct RustcStdInternalSymbol {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::const_trait)]
+#[diag(passes::const_trait)]
 pub struct ConstTrait {
     #[primary_span]
     pub attr_span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::link_ordinal)]
+#[diag(passes::link_ordinal)]
 pub struct LinkOrdinal {
     #[primary_span]
     pub attr_span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::stability_promotable)]
+#[diag(passes::stability_promotable)]
 pub struct StabilityPromotable {
     #[primary_span]
     pub attr_span: Span,
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::deprecated)]
+#[diag(passes::deprecated)]
 pub struct Deprecated;
 
 #[derive(LintDiagnostic)]
-#[lint(passes::macro_use)]
+#[diag(passes::macro_use)]
 pub struct MacroUse {
     pub name: Symbol,
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::macro_export)]
+#[diag(passes::macro_export)]
 pub struct MacroExport;
 
 #[derive(LintDiagnostic)]
-#[lint(passes::plugin_registrar)]
+#[diag(passes::plugin_registrar)]
 pub struct PluginRegistrar;
 
 #[derive(SessionSubdiagnostic)]
@@ -594,7 +594,7 @@ pub enum UnusedNote {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::unused)]
+#[diag(passes::unused)]
 pub struct Unused {
     #[suggestion(applicability = "machine-applicable")]
     pub attr_span: Span,
@@ -603,7 +603,7 @@ pub struct Unused {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::non_exported_macro_invalid_attrs, code = "E0518")]
+#[diag(passes::non_exported_macro_invalid_attrs, code = "E0518")]
 pub struct NonExportedMacroInvalidAttrs {
     #[primary_span]
     #[label]
@@ -611,9 +611,8 @@ pub struct NonExportedMacroInvalidAttrs {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::unused_duplicate)]
+#[diag(passes::unused_duplicate)]
 pub struct UnusedDuplicate {
-    #[primary_span]
     #[suggestion(code = "", applicability = "machine-applicable")]
     pub this: Span,
     #[note]
@@ -623,7 +622,7 @@ pub struct UnusedDuplicate {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::unused_multiple)]
+#[diag(passes::unused_multiple)]
 pub struct UnusedMultiple {
     #[primary_span]
     #[suggestion(code = "", applicability = "machine-applicable")]
@@ -634,7 +633,7 @@ pub struct UnusedMultiple {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::rustc_lint_opt_ty)]
+#[diag(passes::rustc_lint_opt_ty)]
 pub struct RustcLintOptTy {
     #[primary_span]
     pub attr_span: Span,
@@ -643,7 +642,7 @@ pub struct RustcLintOptTy {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::rustc_lint_opt_deny_field_access)]
+#[diag(passes::rustc_lint_opt_deny_field_access)]
 pub struct RustcLintOptDenyFieldAccess {
     #[primary_span]
     pub attr_span: Span,
diff --git a/compiler/rustc_privacy/src/errors.rs b/compiler/rustc_privacy/src/errors.rs
index aca7d770f3495..1e423ddb7102c 100644
--- a/compiler/rustc_privacy/src/errors.rs
+++ b/compiler/rustc_privacy/src/errors.rs
@@ -3,7 +3,7 @@ use rustc_macros::{LintDiagnostic, SessionDiagnostic, SessionSubdiagnostic};
 use rustc_span::{Span, Symbol};
 
 #[derive(SessionDiagnostic)]
-#[error(privacy::field_is_private, code = "E0451")]
+#[diag(privacy::field_is_private, code = "E0451")]
 pub struct FieldIsPrivate {
     #[primary_span]
     pub span: Span,
@@ -30,7 +30,7 @@ pub enum FieldIsPrivateLabel {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(privacy::item_is_private)]
+#[diag(privacy::item_is_private)]
 pub struct ItemIsPrivate<'a> {
     #[primary_span]
     #[label]
@@ -40,7 +40,7 @@ pub struct ItemIsPrivate<'a> {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(privacy::unnamed_item_is_private)]
+#[diag(privacy::unnamed_item_is_private)]
 pub struct UnnamedItemIsPrivate {
     #[primary_span]
     pub span: Span,
@@ -49,7 +49,7 @@ pub struct UnnamedItemIsPrivate {
 
 // Duplicate of `InPublicInterface` but with a different error code, shares the same slug.
 #[derive(SessionDiagnostic)]
-#[error(privacy::in_public_interface, code = "E0445")]
+#[diag(privacy::in_public_interface, code = "E0445")]
 pub struct InPublicInterfaceTraits<'a> {
     #[primary_span]
     #[label]
@@ -63,7 +63,7 @@ pub struct InPublicInterfaceTraits<'a> {
 
 // Duplicate of `InPublicInterfaceTraits` but with a different error code, shares the same slug.
 #[derive(SessionDiagnostic)]
-#[error(privacy::in_public_interface, code = "E0446")]
+#[diag(privacy::in_public_interface, code = "E0446")]
 pub struct InPublicInterface<'a> {
     #[primary_span]
     #[label]
@@ -76,7 +76,7 @@ pub struct InPublicInterface<'a> {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(privacy::from_private_dep_in_public_interface)]
+#[diag(privacy::from_private_dep_in_public_interface)]
 pub struct FromPrivateDependencyInPublicInterface<'a> {
     pub kind: &'a str,
     pub descr: DiagnosticArgFromDisplay<'a>,
@@ -84,7 +84,7 @@ pub struct FromPrivateDependencyInPublicInterface<'a> {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(privacy::private_in_public_lint)]
+#[diag(privacy::private_in_public_lint)]
 pub struct PrivateInPublicLint<'a> {
     pub vis_descr: &'static str,
     pub kind: &'a str,
diff --git a/compiler/rustc_serialize/src/serialize.rs b/compiler/rustc_serialize/src/serialize.rs
index 36585b8d77e0a..9bd5550038fc6 100644
--- a/compiler/rustc_serialize/src/serialize.rs
+++ b/compiler/rustc_serialize/src/serialize.rs
@@ -273,7 +273,7 @@ impl<D: Decoder, T: Decodable<D>> Decodable<D> for Vec<T> {
         unsafe {
             let ptr: *mut T = vec.as_mut_ptr();
             for i in 0..len {
-                std::ptr::write(ptr.offset(i as isize), Decodable::decode(d));
+                std::ptr::write(ptr.add(i), Decodable::decode(d));
             }
             vec.set_len(len);
         }
diff --git a/compiler/rustc_session/src/parse.rs b/compiler/rustc_session/src/parse.rs
index 9f0886cb2089c..b9b2356130a59 100644
--- a/compiler/rustc_session/src/parse.rs
+++ b/compiler/rustc_session/src/parse.rs
@@ -12,7 +12,7 @@ use rustc_data_structures::sync::{Lock, Lrc};
 use rustc_errors::{emitter::SilentEmitter, ColorConfig, Handler};
 use rustc_errors::{
     error_code, fallback_fluent_bundle, Applicability, Diagnostic, DiagnosticBuilder, DiagnosticId,
-    DiagnosticMessage, ErrorGuaranteed, MultiSpan, StashKey,
+    DiagnosticMessage, EmissionGuarantee, ErrorGuaranteed, MultiSpan, StashKey,
 };
 use rustc_feature::{find_feature_issue, GateIssue, UnstableFeatures};
 use rustc_span::edition::Edition;
@@ -372,4 +372,12 @@ impl ParseSess {
     pub fn struct_warn(&self, msg: impl Into<DiagnosticMessage>) -> DiagnosticBuilder<'_, ()> {
         self.span_diagnostic.struct_warn(msg)
     }
+
+    #[rustc_lint_diagnostics]
+    pub fn struct_diagnostic<G: EmissionGuarantee>(
+        &self,
+        msg: impl Into<DiagnosticMessage>,
+    ) -> DiagnosticBuilder<'_, G> {
+        self.span_diagnostic.struct_diagnostic(msg)
+    }
 }
diff --git a/compiler/rustc_span/src/lib.rs b/compiler/rustc_span/src/lib.rs
index d14e28e85be1a..860af7fe93a07 100644
--- a/compiler/rustc_span/src/lib.rs
+++ b/compiler/rustc_span/src/lib.rs
@@ -664,6 +664,16 @@ impl Span {
         Some(self)
     }
 
+    /// Like `find_ancestor_inside`, but specifically for when spans might not
+    /// overlaps. Take care when using this, and prefer `find_ancestor_inside`
+    /// when you know that the spans are nested (modulo macro expansion).
+    pub fn find_ancestor_in_same_ctxt(mut self, other: Span) -> Option<Span> {
+        while !Span::eq_ctxt(self, other) {
+            self = self.parent_callsite()?;
+        }
+        Some(self)
+    }
+
     /// Edition of the crate from which this span came.
     pub fn edition(self) -> edition::Edition {
         self.ctxt().edition()
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
index 1a39a1680384d..70fac83325a9c 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
@@ -860,8 +860,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
                             }
                         }
 
-                        err.emit();
-                        return;
+                        err
                     }
 
                     ty::PredicateKind::WellFormed(ty) => {
@@ -1564,6 +1563,8 @@ impl<'a, 'tcx> InferCtxtPrivExt<'a, 'tcx> for InferCtxt<'a, 'tcx> {
                     obligation.cause.code().peel_derives(),
                     ObligationCauseCode::ItemObligation(_)
                         | ObligationCauseCode::BindingObligation(_, _)
+                        | ObligationCauseCode::ExprItemObligation(..)
+                        | ObligationCauseCode::ExprBindingObligation(..)
                         | ObligationCauseCode::ObjectCastObligation(..)
                         | ObligationCauseCode::OpaqueType
                 );
@@ -2091,13 +2092,11 @@ impl<'a, 'tcx> InferCtxtPrivExt<'a, 'tcx> for InferCtxt<'a, 'tcx> {
                     }
                 }
 
-                if let ObligationCauseCode::ItemObligation(def_id) = *obligation.cause.code() {
+                if let ObligationCauseCode::ItemObligation(def_id) | ObligationCauseCode::ExprItemObligation(def_id, ..) = *obligation.cause.code() {
                     self.suggest_fully_qualified_path(&mut err, def_id, span, trait_ref.def_id());
-                } else if let (
-                    Ok(ref snippet),
-                    &ObligationCauseCode::BindingObligation(def_id, _),
-                ) =
-                    (self.tcx.sess.source_map().span_to_snippet(span), obligation.cause.code())
+                } else if let Ok(snippet) = &self.tcx.sess.source_map().span_to_snippet(span)
+                    && let ObligationCauseCode::BindingObligation(def_id, _) | ObligationCauseCode::ExprBindingObligation(def_id, ..)
+                        = *obligation.cause.code()
                 {
                     let generics = self.tcx.generics_of(def_id);
                     if generics.params.iter().any(|p| p.name != kw::SelfUpper)
@@ -2520,15 +2519,10 @@ impl<'a, 'tcx> InferCtxtPrivExt<'a, 'tcx> for InferCtxt<'a, 'tcx> {
         err: &mut Diagnostic,
         obligation: &PredicateObligation<'tcx>,
     ) {
-        let (
-            ty::PredicateKind::Trait(pred),
-            &ObligationCauseCode::BindingObligation(item_def_id, span),
-        ) = (
-            obligation.predicate.kind().skip_binder(),
-            obligation.cause.code().peel_derives(),
-        )  else {
-            return;
-        };
+        let ty::PredicateKind::Trait(pred) = obligation.predicate.kind().skip_binder() else { return; };
+        let (ObligationCauseCode::BindingObligation(item_def_id, span)
+        | ObligationCauseCode::ExprBindingObligation(item_def_id, span, ..))
+            = *obligation.cause.code().peel_derives() else { return; };
         debug!(?pred, ?item_def_id, ?span);
 
         let (Some(node), true) = (
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs
index e6907637c57b6..6b03555bc6985 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs
@@ -143,7 +143,9 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
         }
 
         if let ObligationCauseCode::ItemObligation(item)
-        | ObligationCauseCode::BindingObligation(item, _) = *obligation.cause.code()
+        | ObligationCauseCode::BindingObligation(item, _)
+        | ObligationCauseCode::ExprItemObligation(item, ..)
+        | ObligationCauseCode::ExprBindingObligation(item, ..) = *obligation.cause.code()
         {
             // FIXME: maybe also have some way of handling methods
             // from other traits? That would require name resolution,
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
index 0d279069694a9..a93f9ec0397d2 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
@@ -671,11 +671,16 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
         trait_pred: ty::PolyTraitPredicate<'tcx>,
     ) -> bool {
         // It only make sense when suggesting dereferences for arguments
-        let ObligationCauseCode::FunctionArgumentObligation { arg_hir_id, .. } = obligation.cause.code() else {
-            return false;
-        };
-        let param_env = obligation.param_env;
-        let body_id = obligation.cause.body_id;
+        let ObligationCauseCode::FunctionArgumentObligation { arg_hir_id, .. } = obligation.cause.code()
+            else { return false; };
+        let Some(typeck_results) = self.in_progress_typeck_results
+            else { return false; };
+        let typeck_results = typeck_results.borrow();
+        let hir::Node::Expr(expr) = self.tcx.hir().get(*arg_hir_id)
+            else { return false; };
+        let Some(arg_ty) = typeck_results.expr_ty_adjusted_opt(expr)
+            else { return false; };
+
         let span = obligation.cause.span;
         let mut real_trait_pred = trait_pred;
         let mut code = obligation.cause.code();
@@ -687,9 +692,19 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
 
             // Skipping binder here, remapping below
             let real_ty = real_trait_pred.self_ty().skip_binder();
+            if self.can_eq(obligation.param_env, real_ty, arg_ty).is_err() {
+                continue;
+            }
 
             if let ty::Ref(region, base_ty, mutbl) = *real_ty.kind() {
-                let mut autoderef = Autoderef::new(self, param_env, body_id, span, base_ty, span);
+                let mut autoderef = Autoderef::new(
+                    self,
+                    obligation.param_env,
+                    obligation.cause.body_id,
+                    span,
+                    base_ty,
+                    span,
+                );
                 if let Some(steps) = autoderef.find_map(|(ty, steps)| {
                     // Re-add the `&`
                     let ty = self.tcx.mk_ref(region, TypeAndMut { ty, mutbl });
@@ -697,8 +712,10 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
                     // Remapping bound vars here
                     let real_trait_pred_and_ty =
                         real_trait_pred.map_bound(|inner_trait_pred| (inner_trait_pred, ty));
-                    let obligation = self
-                        .mk_trait_obligation_with_new_self_ty(param_env, real_trait_pred_and_ty);
+                    let obligation = self.mk_trait_obligation_with_new_self_ty(
+                        obligation.param_env,
+                        real_trait_pred_and_ty,
+                    );
                     Some(steps).filter(|_| self.predicate_may_hold(&obligation))
                 }) {
                     if steps > 0 {
@@ -727,7 +744,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
                     let real_trait_pred_and_base_ty =
                         real_trait_pred.map_bound(|inner_trait_pred| (inner_trait_pred, base_ty));
                     let obligation = self.mk_trait_obligation_with_new_self_ty(
-                        param_env,
+                        obligation.param_env,
                         real_trait_pred_and_base_ty,
                     );
                     if self.predicate_may_hold(&obligation) {
@@ -855,6 +872,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
             _ => return false,
         };
         if matches!(obligation.cause.code(), ObligationCauseCode::FunctionArgumentObligation { .. })
+            && obligation.cause.span.can_be_used_for_suggestions()
         {
             // When the obligation error has been ensured to have been caused by
             // an argument, the `obligation.cause.span` points at the expression
@@ -885,7 +903,9 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
             obligation.cause.code()
         {
             &parent_code
-        } else if let ObligationCauseCode::ItemObligation(_) = obligation.cause.code() {
+        } else if let ObligationCauseCode::ItemObligation(_)
+        | ObligationCauseCode::ExprItemObligation(..) = obligation.cause.code()
+        {
             obligation.cause.code()
         } else if let ExpnKind::Desugaring(DesugaringKind::ForLoop) =
             span.ctxt().outer_expn_data().kind
@@ -911,35 +931,36 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
         let param_env = obligation.param_env;
 
         // Try to apply the original trait binding obligation by borrowing.
-        let mut try_borrowing =
-            |old_pred: ty::PolyTraitPredicate<'tcx>, blacklist: &[DefId]| -> bool {
-                if blacklist.contains(&old_pred.def_id()) {
-                    return false;
-                }
-                // We map bounds to `&T` and `&mut T`
-                let trait_pred_and_imm_ref = old_pred.map_bound(|trait_pred| {
-                    (
-                        trait_pred,
-                        self.tcx.mk_imm_ref(self.tcx.lifetimes.re_static, trait_pred.self_ty()),
-                    )
-                });
-                let trait_pred_and_mut_ref = old_pred.map_bound(|trait_pred| {
-                    (
-                        trait_pred,
-                        self.tcx.mk_mut_ref(self.tcx.lifetimes.re_static, trait_pred.self_ty()),
-                    )
-                });
+        let mut try_borrowing = |old_pred: ty::PolyTraitPredicate<'tcx>,
+                                 blacklist: &[DefId]|
+         -> bool {
+            if blacklist.contains(&old_pred.def_id()) {
+                return false;
+            }
+            // We map bounds to `&T` and `&mut T`
+            let trait_pred_and_imm_ref = old_pred.map_bound(|trait_pred| {
+                (
+                    trait_pred,
+                    self.tcx.mk_imm_ref(self.tcx.lifetimes.re_static, trait_pred.self_ty()),
+                )
+            });
+            let trait_pred_and_mut_ref = old_pred.map_bound(|trait_pred| {
+                (
+                    trait_pred,
+                    self.tcx.mk_mut_ref(self.tcx.lifetimes.re_static, trait_pred.self_ty()),
+                )
+            });
 
-                let mk_result = |trait_pred_and_new_ty| {
-                    let obligation =
-                        self.mk_trait_obligation_with_new_self_ty(param_env, trait_pred_and_new_ty);
-                    self.predicate_must_hold_modulo_regions(&obligation)
-                };
-                let imm_ref_self_ty_satisfies_pred = mk_result(trait_pred_and_imm_ref);
-                let mut_ref_self_ty_satisfies_pred = mk_result(trait_pred_and_mut_ref);
+            let mk_result = |trait_pred_and_new_ty| {
+                let obligation =
+                    self.mk_trait_obligation_with_new_self_ty(param_env, trait_pred_and_new_ty);
+                self.predicate_must_hold_modulo_regions(&obligation)
+            };
+            let imm_ref_self_ty_satisfies_pred = mk_result(trait_pred_and_imm_ref);
+            let mut_ref_self_ty_satisfies_pred = mk_result(trait_pred_and_mut_ref);
 
-                let (ref_inner_ty_satisfies_pred, ref_inner_ty_mut) =
-                if let ObligationCauseCode::ItemObligation(_) = obligation.cause.code()
+            let (ref_inner_ty_satisfies_pred, ref_inner_ty_mut) =
+                if let ObligationCauseCode::ItemObligation(_) | ObligationCauseCode::ExprItemObligation(..) = obligation.cause.code()
                     && let ty::Ref(_, ty, mutability) = old_pred.self_ty().skip_binder().kind()
                 {
                     (
@@ -950,79 +971,81 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
                     (false, false)
                 };
 
-                if imm_ref_self_ty_satisfies_pred
-                    || mut_ref_self_ty_satisfies_pred
-                    || ref_inner_ty_satisfies_pred
-                {
-                    if let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(span) {
-                        // We have a very specific type of error, where just borrowing this argument
-                        // might solve the problem. In cases like this, the important part is the
-                        // original type obligation, not the last one that failed, which is arbitrary.
-                        // Because of this, we modify the error to refer to the original obligation and
-                        // return early in the caller.
-
-                        let msg = format!("the trait bound `{}` is not satisfied", old_pred);
-                        if has_custom_message {
-                            err.note(&msg);
-                        } else {
-                            err.message =
-                                vec![(rustc_errors::DiagnosticMessage::Str(msg), Style::NoStyle)];
-                        }
-                        if snippet.starts_with('&') {
-                            // This is already a literal borrow and the obligation is failing
-                            // somewhere else in the obligation chain. Do not suggest non-sense.
-                            return false;
-                        }
-                        err.span_label(
-                            span,
+            if imm_ref_self_ty_satisfies_pred
+                || mut_ref_self_ty_satisfies_pred
+                || ref_inner_ty_satisfies_pred
+            {
+                if let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(span) {
+                    // We don't want a borrowing suggestion on the fields in structs,
+                    // ```
+                    // struct Foo {
+                    //  the_foos: Vec<Foo>
+                    // }
+                    // ```
+                    if !matches!(
+                        span.ctxt().outer_expn_data().kind,
+                        ExpnKind::Root | ExpnKind::Desugaring(DesugaringKind::ForLoop)
+                    ) {
+                        return false;
+                    }
+                    if snippet.starts_with('&') {
+                        // This is already a literal borrow and the obligation is failing
+                        // somewhere else in the obligation chain. Do not suggest non-sense.
+                        return false;
+                    }
+                    // We have a very specific type of error, where just borrowing this argument
+                    // might solve the problem. In cases like this, the important part is the
+                    // original type obligation, not the last one that failed, which is arbitrary.
+                    // Because of this, we modify the error to refer to the original obligation and
+                    // return early in the caller.
+
+                    let msg = format!("the trait bound `{}` is not satisfied", old_pred);
+                    if has_custom_message {
+                        err.note(&msg);
+                    } else {
+                        err.message =
+                            vec![(rustc_errors::DiagnosticMessage::Str(msg), Style::NoStyle)];
+                    }
+                    err.span_label(
+                        span,
+                        format!(
+                            "the trait `{}` is not implemented for `{}`",
+                            old_pred.print_modifiers_and_trait_path(),
+                            old_pred.self_ty().skip_binder(),
+                        ),
+                    );
+
+                    if imm_ref_self_ty_satisfies_pred && mut_ref_self_ty_satisfies_pred {
+                        err.span_suggestions(
+                            span.shrink_to_lo(),
+                            "consider borrowing here",
+                            ["&".to_string(), "&mut ".to_string()].into_iter(),
+                            Applicability::MaybeIncorrect,
+                        );
+                    } else {
+                        let is_mut = mut_ref_self_ty_satisfies_pred || ref_inner_ty_mut;
+                        err.span_suggestion_verbose(
+                            span.shrink_to_lo(),
                             &format!(
-                                "expected an implementor of trait `{}`",
-                                old_pred.print_modifiers_and_trait_path(),
+                                "consider{} borrowing here",
+                                if is_mut { " mutably" } else { "" }
                             ),
+                            format!("&{}", if is_mut { "mut " } else { "" }),
+                            Applicability::MaybeIncorrect,
                         );
-
-                        // This if is to prevent a special edge-case
-                        if matches!(
-                            span.ctxt().outer_expn_data().kind,
-                            ExpnKind::Root | ExpnKind::Desugaring(DesugaringKind::ForLoop)
-                        ) {
-                            // We don't want a borrowing suggestion on the fields in structs,
-                            // ```
-                            // struct Foo {
-                            //  the_foos: Vec<Foo>
-                            // }
-                            // ```
-
-                            if imm_ref_self_ty_satisfies_pred && mut_ref_self_ty_satisfies_pred {
-                                err.span_suggestions(
-                                    span.shrink_to_lo(),
-                                    "consider borrowing here",
-                                    ["&".to_string(), "&mut ".to_string()].into_iter(),
-                                    Applicability::MaybeIncorrect,
-                                );
-                            } else {
-                                let is_mut = mut_ref_self_ty_satisfies_pred || ref_inner_ty_mut;
-                                err.span_suggestion_verbose(
-                                    span.shrink_to_lo(),
-                                    &format!(
-                                        "consider{} borrowing here",
-                                        if is_mut { " mutably" } else { "" }
-                                    ),
-                                    format!("&{}", if is_mut { "mut " } else { "" }),
-                                    Applicability::MaybeIncorrect,
-                                );
-                            }
-                        }
-                        return true;
                     }
+                    return true;
                 }
-                return false;
-            };
+            }
+            return false;
+        };
 
         if let ObligationCauseCode::ImplDerivedObligation(cause) = &*code {
             try_borrowing(cause.derived.parent_trait_pred, &[])
         } else if let ObligationCauseCode::BindingObligation(_, _)
-        | ObligationCauseCode::ItemObligation(..) = code
+        | ObligationCauseCode::ItemObligation(_)
+        | ObligationCauseCode::ExprItemObligation(..)
+        | ObligationCauseCode::ExprBindingObligation(..) = code
         {
             try_borrowing(poly_trait_pred, &never_suggest_borrow)
         } else {
@@ -2244,11 +2267,13 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
                     region, object_ty,
                 ));
             }
-            ObligationCauseCode::ItemObligation(_item_def_id) => {
+            ObligationCauseCode::ItemObligation(_)
+            | ObligationCauseCode::ExprItemObligation(..) => {
                 // We hold the `DefId` of the item introducing the obligation, but displaying it
                 // doesn't add user usable information. It always point at an associated item.
             }
-            ObligationCauseCode::BindingObligation(item_def_id, span) => {
+            ObligationCauseCode::BindingObligation(item_def_id, span)
+            | ObligationCauseCode::ExprBindingObligation(item_def_id, span, ..) => {
                 let item_name = tcx.def_path_str(item_def_id);
                 let mut multispan = MultiSpan::from(span);
                 if let Some(ident) = tcx.opt_item_ident(item_def_id) {
diff --git a/compiler/rustc_trait_selection/src/traits/mod.rs b/compiler/rustc_trait_selection/src/traits/mod.rs
index b6d6df1eec6a1..85ff6e23711ca 100644
--- a/compiler/rustc_trait_selection/src/traits/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/mod.rs
@@ -117,11 +117,21 @@ pub enum TraitQueryMode {
 
 /// Creates predicate obligations from the generic bounds.
 pub fn predicates_for_generics<'tcx>(
-    cause: ObligationCause<'tcx>,
+    cause: impl Fn(usize, Span) -> ObligationCause<'tcx>,
     param_env: ty::ParamEnv<'tcx>,
     generic_bounds: ty::InstantiatedPredicates<'tcx>,
 ) -> impl Iterator<Item = PredicateObligation<'tcx>> {
-    util::predicates_for_generics(cause, 0, param_env, generic_bounds)
+    let generic_bounds = generic_bounds;
+    debug!("predicates_for_generics(generic_bounds={:?})", generic_bounds);
+
+    std::iter::zip(generic_bounds.predicates, generic_bounds.spans).enumerate().map(
+        move |(idx, (predicate, span))| Obligation {
+            cause: cause(idx, span),
+            recursion_depth: 0,
+            param_env: param_env,
+            predicate,
+        },
+    )
 }
 
 /// Determines whether the type `ty` is known to meet `bound` and
diff --git a/compiler/rustc_trait_selection/src/traits/util.rs b/compiler/rustc_trait_selection/src/traits/util.rs
index d25006016629c..0f5dff01c6625 100644
--- a/compiler/rustc_trait_selection/src/traits/util.rs
+++ b/compiler/rustc_trait_selection/src/traits/util.rs
@@ -11,8 +11,6 @@ use rustc_middle::ty::{self, ImplSubject, ToPredicate, Ty, TyCtxt, TypeVisitable
 use super::{Normalized, Obligation, ObligationCause, PredicateObligation, SelectionContext};
 pub use rustc_infer::traits::{self, util::*};
 
-use std::iter;
-
 ///////////////////////////////////////////////////////////////////////////
 // `TraitAliasExpander` iterator
 ///////////////////////////////////////////////////////////////////////////
@@ -210,7 +208,7 @@ pub fn impl_subject_and_oblig<'a, 'tcx>(
     let Normalized { value: predicates, obligations: normalization_obligations2 } =
         super::normalize(selcx, param_env, ObligationCause::dummy(), predicates);
     let impl_obligations =
-        predicates_for_generics(ObligationCause::dummy(), 0, param_env, predicates);
+        super::predicates_for_generics(|_, _| ObligationCause::dummy(), param_env, predicates);
 
     let impl_obligations = impl_obligations
         .chain(normalization_obligations1.into_iter())
@@ -219,27 +217,6 @@ pub fn impl_subject_and_oblig<'a, 'tcx>(
     (subject, impl_obligations)
 }
 
-pub fn predicates_for_generics<'tcx>(
-    cause: ObligationCause<'tcx>,
-    recursion_depth: usize,
-    param_env: ty::ParamEnv<'tcx>,
-    generic_bounds: ty::InstantiatedPredicates<'tcx>,
-) -> impl Iterator<Item = PredicateObligation<'tcx>> {
-    debug!("predicates_for_generics(generic_bounds={:?})", generic_bounds);
-
-    iter::zip(generic_bounds.predicates, generic_bounds.spans).map(move |(predicate, span)| {
-        let cause = match *cause.code() {
-            traits::ItemObligation(def_id) if !span.is_dummy() => traits::ObligationCause::new(
-                cause.span,
-                cause.body_id,
-                traits::BindingObligation(def_id, span),
-            ),
-            _ => cause.clone(),
-        };
-        Obligation { cause, recursion_depth, param_env, predicate }
-    })
-}
-
 pub fn predicate_for_trait_ref<'tcx>(
     tcx: TyCtxt<'tcx>,
     cause: ObligationCause<'tcx>,
diff --git a/compiler/rustc_trait_selection/src/traits/wf.rs b/compiler/rustc_trait_selection/src/traits/wf.rs
index 7a5e67ff74b32..4bd179d239131 100644
--- a/compiler/rustc_trait_selection/src/traits/wf.rs
+++ b/compiler/rustc_trait_selection/src/traits/wf.rs
@@ -711,7 +711,7 @@ impl<'tcx> WfPredicates<'tcx> {
         iter::zip(iter::zip(predicates.predicates, predicates.spans), origins.into_iter().rev())
             .map(|((mut pred, span), origin_def_id)| {
                 let code = if span.is_dummy() {
-                    traits::MiscObligation
+                    traits::ItemObligation(origin_def_id)
                 } else {
                     traits::BindingObligation(origin_def_id, span)
                 };
diff --git a/compiler/rustc_transmute/src/lib.rs b/compiler/rustc_transmute/src/lib.rs
index cfc7c752a6bd6..32e6cb9c64f7f 100644
--- a/compiler/rustc_transmute/src/lib.rs
+++ b/compiler/rustc_transmute/src/lib.rs
@@ -7,6 +7,8 @@
     result_into_ok_or_err
 )]
 #![allow(dead_code, unused_variables)]
+#![deny(rustc::untranslatable_diagnostic)]
+#![deny(rustc::diagnostic_outside_of_impl)]
 
 #[macro_use]
 extern crate tracing;
diff --git a/compiler/rustc_typeck/src/check/compare_method.rs b/compiler/rustc_typeck/src/check/compare_method.rs
index ec8d22e81d1c0..64846953aac75 100644
--- a/compiler/rustc_typeck/src/check/compare_method.rs
+++ b/compiler/rustc_typeck/src/check/compare_method.rs
@@ -1463,7 +1463,7 @@ pub fn check_type_bounds<'tcx>(
         );
         let mk_cause = |span: Span| {
             let code = if span.is_dummy() {
-                traits::MiscObligation
+                traits::ItemObligation(trait_ty.def_id)
             } else {
                 traits::BindingObligation(trait_ty.def_id, span)
             };
diff --git a/compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs b/compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs
index 1d9d04ceec0d7..20d25d508d224 100644
--- a/compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs
+++ b/compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs
@@ -607,9 +607,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
     #[instrument(skip(self), level = "debug")]
     pub(in super::super) fn select_all_obligations_or_error(&self) {
-        let errors = self.fulfillment_cx.borrow_mut().select_all_or_error(&self);
+        let mut errors = self.fulfillment_cx.borrow_mut().select_all_or_error(&self);
 
         if !errors.is_empty() {
+            self.adjust_fulfillment_errors_for_expr_obligation(&mut errors);
             self.report_fulfillment_errors(&errors, self.inh.body_id, false);
         }
     }
@@ -623,6 +624,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let mut result = self.fulfillment_cx.borrow_mut().select_where_possible(self);
         if !result.is_empty() {
             mutate_fulfillment_errors(&mut result);
+            self.adjust_fulfillment_errors_for_expr_obligation(&mut result);
             self.report_fulfillment_errors(&result, self.inh.body_id, fallback_has_occurred);
         }
     }
@@ -820,23 +822,25 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let ty = item_ty.subst(self.tcx, substs);
 
         self.write_resolution(hir_id, Ok((def_kind, def_id)));
-        self.add_required_obligations_with_code(
-            span,
-            def_id,
-            &substs,
-            match lang_item {
-                hir::LangItem::IntoFutureIntoFuture => {
-                    ObligationCauseCode::AwaitableExpr(expr_hir_id)
-                }
-                hir::LangItem::IteratorNext | hir::LangItem::IntoIterIntoIter => {
-                    ObligationCauseCode::ForLoopIterator
-                }
-                hir::LangItem::TryTraitFromOutput
-                | hir::LangItem::TryTraitFromResidual
-                | hir::LangItem::TryTraitBranch => ObligationCauseCode::QuestionMark,
-                _ => traits::ItemObligation(def_id),
-            },
-        );
+
+        let code = match lang_item {
+            hir::LangItem::IntoFutureIntoFuture => {
+                Some(ObligationCauseCode::AwaitableExpr(expr_hir_id))
+            }
+            hir::LangItem::IteratorNext | hir::LangItem::IntoIterIntoIter => {
+                Some(ObligationCauseCode::ForLoopIterator)
+            }
+            hir::LangItem::TryTraitFromOutput
+            | hir::LangItem::TryTraitFromResidual
+            | hir::LangItem::TryTraitBranch => Some(ObligationCauseCode::QuestionMark),
+            _ => None,
+        };
+        if let Some(code) = code {
+            self.add_required_obligations_with_code(span, def_id, substs, move |_, _| code.clone());
+        } else {
+            self.add_required_obligations_for_hir(span, def_id, substs, hir_id);
+        }
+
         (Res::Def(def_kind, def_id), ty)
     }
 
@@ -1348,7 +1352,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // First, store the "user substs" for later.
         self.write_user_type_annotation_from_substs(hir_id, def_id, substs, user_self_ty);
 
-        self.add_required_obligations(span, def_id, &substs);
+        self.add_required_obligations_for_hir(span, def_id, &substs, hir_id);
 
         // Substitute the values for the type parameters into the type of
         // the referenced item.
@@ -1385,32 +1389,36 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     }
 
     /// Add all the obligations that are required, substituting and normalized appropriately.
-    pub(crate) fn add_required_obligations(
+    pub(crate) fn add_required_obligations_for_hir(
         &self,
         span: Span,
         def_id: DefId,
-        substs: &SubstsRef<'tcx>,
+        substs: SubstsRef<'tcx>,
+        hir_id: hir::HirId,
     ) {
-        self.add_required_obligations_with_code(
-            span,
-            def_id,
-            substs,
-            traits::ItemObligation(def_id),
-        )
+        self.add_required_obligations_with_code(span, def_id, substs, |idx, span| {
+            if span.is_dummy() {
+                ObligationCauseCode::ExprItemObligation(def_id, hir_id, idx)
+            } else {
+                ObligationCauseCode::ExprBindingObligation(def_id, span, hir_id, idx)
+            }
+        })
     }
 
-    #[tracing::instrument(level = "debug", skip(self, span, def_id, substs))]
+    #[tracing::instrument(level = "debug", skip(self, code, span, def_id, substs))]
     fn add_required_obligations_with_code(
         &self,
         span: Span,
         def_id: DefId,
-        substs: &SubstsRef<'tcx>,
-        code: ObligationCauseCode<'tcx>,
+        substs: SubstsRef<'tcx>,
+        code: impl Fn(usize, Span) -> ObligationCauseCode<'tcx>,
     ) {
         let (bounds, _) = self.instantiate_bounds(span, def_id, &substs);
 
         for obligation in traits::predicates_for_generics(
-            traits::ObligationCause::new(span, self.body_id, code),
+            |idx, predicate_span| {
+                traits::ObligationCause::new(span, self.body_id, code(idx, predicate_span))
+            },
             self.param_env,
             bounds,
         ) {
diff --git a/compiler/rustc_typeck/src/check/fn_ctxt/checks.rs b/compiler/rustc_typeck/src/check/fn_ctxt/checks.rs
index aab60de80ef14..3642b2ab03bfa 100644
--- a/compiler/rustc_typeck/src/check/fn_ctxt/checks.rs
+++ b/compiler/rustc_typeck/src/check/fn_ctxt/checks.rs
@@ -15,6 +15,7 @@ use crate::check::{
 use crate::structured_errors::StructuredDiagnostic;
 
 use rustc_ast as ast;
+use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::{pluralize, Applicability, Diagnostic, DiagnosticId, MultiSpan};
 use rustc_hir as hir;
 use rustc_hir::def::{CtorOf, DefKind, Res};
@@ -27,13 +28,14 @@ use rustc_infer::infer::InferOk;
 use rustc_infer::infer::TypeTrace;
 use rustc_middle::ty::adjustment::AllowTwoPhase;
 use rustc_middle::ty::visit::TypeVisitable;
-use rustc_middle::ty::{self, DefIdTree, IsSuggestable, Ty};
+use rustc_middle::ty::{self, DefIdTree, IsSuggestable, Ty, TypeSuperVisitable, TypeVisitor};
 use rustc_session::Session;
 use rustc_span::symbol::Ident;
 use rustc_span::{self, Span};
 use rustc_trait_selection::traits::{self, ObligationCauseCode, SelectionContext};
 
 use std::iter;
+use std::ops::ControlFlow;
 use std::slice;
 
 impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
@@ -247,17 +249,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // Cause selection errors caused by resolving a single argument to point at the
             // argument and not the call. This lets us customize the span pointed to in the
             // fulfillment error to be more accurate.
-            let coerced_ty =
-                self.resolve_vars_with_obligations_and_mutate_fulfillment(coerced_ty, |errors| {
-                    self.point_at_type_arg_instead_of_call_if_possible(errors, call_expr);
-                    self.point_at_arg_instead_of_call_if_possible(
-                        errors,
-                        call_expr,
-                        call_span,
-                        provided_args,
-                        &expected_input_tys,
-                    );
-                });
+            let coerced_ty = self.resolve_vars_with_obligations(coerced_ty);
 
             let coerce_error = self
                 .try_coerce(provided_arg, checked_ty, coerced_ty, AllowTwoPhase::Yes, None)
@@ -312,16 +304,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // an "opportunistic" trait resolution of any trait bounds on
             // the call. This helps coercions.
             if check_closures {
-                self.select_obligations_where_possible(false, |errors| {
-                    self.point_at_type_arg_instead_of_call_if_possible(errors, call_expr);
-                    self.point_at_arg_instead_of_call_if_possible(
-                        errors,
-                        call_expr,
-                        call_span,
-                        &provided_args,
-                        &expected_input_tys,
-                    );
-                })
+                self.select_obligations_where_possible(false, |_| {})
             }
 
             // Check each argument, to satisfy the input it was provided for
@@ -674,7 +657,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             Applicability::MachineApplicable,
                         );
                     };
-                    self.label_fn_like(&mut err, fn_def_id, callee_ty, Some(mismatch_idx), is_method);
+                    self.label_fn_like(
+                        &mut err,
+                        fn_def_id,
+                        callee_ty,
+                        Some(mismatch_idx),
+                        is_method,
+                    );
                     err.emit();
                     return;
                 }
@@ -1081,8 +1070,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 }
                 let suggestion_text = if let Some(provided_idx) = provided_idx
                     && let (_, provided_span) = provided_arg_tys[*provided_idx]
-                    && let Ok(arg_text) =
-                        source_map.span_to_snippet(provided_span)
+                    && let Ok(arg_text) = source_map.span_to_snippet(provided_span)
                 {
                     arg_text
                 } else {
@@ -1183,7 +1171,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             self.write_user_type_annotation_from_substs(hir_id, did, substs, None);
 
             // Check bounds on type arguments used in the path.
-            self.add_required_obligations(path_span, did, substs);
+            self.add_required_obligations_for_hir(path_span, did, substs, hir_id);
 
             Some((variant, ty))
         } else {
@@ -1620,183 +1608,406 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    /// Given a vec of evaluated `FulfillmentError`s and an `fn` call argument expressions, we walk
-    /// the checked and coerced types for each argument to see if any of the `FulfillmentError`s
-    /// reference a type argument. The reason to walk also the checked type is that the coerced type
-    /// can be not easily comparable with predicate type (because of coercion). If the types match
-    /// for either checked or coerced type, and there's only *one* argument that does, we point at
-    /// the corresponding argument's expression span instead of the `fn` call path span.
-    fn point_at_arg_instead_of_call_if_possible(
+    /// Given a vector of fulfillment errors, try to adjust the spans of the
+    /// errors to more accurately point at the cause of the failure.
+    ///
+    /// This applies to calls, methods, and struct expressions. This will also
+    /// try to deduplicate errors that are due to the same cause but might
+    /// have been created with different [`ObligationCause`][traits::ObligationCause]s.
+    pub(super) fn adjust_fulfillment_errors_for_expr_obligation(
         &self,
         errors: &mut Vec<traits::FulfillmentError<'tcx>>,
-        expr: &'tcx hir::Expr<'tcx>,
-        call_sp: Span,
-        args: &'tcx [hir::Expr<'tcx>],
-        expected_tys: &[Ty<'tcx>],
     ) {
-        // We *do not* do this for desugared call spans to keep good diagnostics when involving
-        // the `?` operator.
-        if call_sp.desugaring_kind().is_some() {
-            return;
+        // Store a mapping from `(Span, Predicate) -> ObligationCause`, so that
+        // other errors that have the same span and predicate can also get fixed,
+        // even if their `ObligationCauseCode` isn't an `Expr*Obligation` kind.
+        // This is important since if we adjust one span but not the other, then
+        // we will have "duplicated" the error on the UI side.
+        let mut remap_cause = FxHashSet::default();
+        let mut not_adjusted = vec![];
+
+        for error in errors {
+            let before_span = error.obligation.cause.span;
+            if self.adjust_fulfillment_error_for_expr_obligation(error)
+                || before_span != error.obligation.cause.span
+            {
+                // Store both the predicate and the predicate *without constness*
+                // since sometimes we instantiate and check both of these in a
+                // method call, for example.
+                remap_cause.insert((
+                    before_span,
+                    error.obligation.predicate,
+                    error.obligation.cause.clone(),
+                ));
+                remap_cause.insert((
+                    before_span,
+                    error.obligation.predicate.without_const(self.tcx),
+                    error.obligation.cause.clone(),
+                ));
+            } else {
+                // If it failed to be adjusted once around, it may be adjusted
+                // via the "remap cause" mapping the second time...
+                not_adjusted.push(error);
+            }
         }
 
-        'outer: for error in errors {
-            // Only if the cause is somewhere inside the expression we want try to point at arg.
-            // Otherwise, it means that the cause is somewhere else and we should not change
-            // anything because we can break the correct span.
-            if !call_sp.contains(error.obligation.cause.span) {
-                continue;
+        for error in not_adjusted {
+            for (span, predicate, cause) in &remap_cause {
+                if *predicate == error.obligation.predicate
+                    && span.contains(error.obligation.cause.span)
+                {
+                    error.obligation.cause = cause.clone();
+                    continue;
+                }
             }
+        }
+    }
 
-            // Peel derived obligation, because it's the type that originally
-            // started this inference chain that matters, not the one we wound
-            // up with at the end.
-            fn unpeel_to_top<'a, 'tcx>(
-                mut code: &'a ObligationCauseCode<'tcx>,
-            ) -> &'a ObligationCauseCode<'tcx> {
-                let mut result_code = code;
-                loop {
-                    let parent = match code {
-                        ObligationCauseCode::ImplDerivedObligation(c) => &c.derived.parent_code,
-                        ObligationCauseCode::BuiltinDerivedObligation(c)
-                        | ObligationCauseCode::DerivedObligation(c) => &c.parent_code,
-                        _ => break result_code,
-                    };
-                    (result_code, code) = (code, parent);
+    fn adjust_fulfillment_error_for_expr_obligation(
+        &self,
+        error: &mut traits::FulfillmentError<'tcx>,
+    ) -> bool {
+        let (traits::ExprItemObligation(def_id, hir_id, idx) | traits::ExprBindingObligation(def_id, _, hir_id, idx))
+            = *error.obligation.cause.code().peel_derives() else { return false; };
+        let hir = self.tcx.hir();
+        let hir::Node::Expr(expr) = hir.get(hir_id) else { return false; };
+
+        // Skip over mentioning async lang item
+        if Some(def_id) == self.tcx.lang_items().from_generator_fn()
+            && error.obligation.cause.span.desugaring_kind()
+                == Some(rustc_span::DesugaringKind::Async)
+        {
+            return false;
+        }
+
+        let Some(unsubstituted_pred) =
+            self.tcx.predicates_of(def_id).instantiate_identity(self.tcx).predicates.into_iter().nth(idx)
+            else { return false; };
+
+        let generics = self.tcx.generics_of(def_id);
+        let predicate_substs = match unsubstituted_pred.kind().skip_binder() {
+            ty::PredicateKind::Trait(pred) => pred.trait_ref.substs,
+            ty::PredicateKind::Projection(pred) => pred.projection_ty.substs,
+            _ => ty::List::empty(),
+        };
+
+        let find_param_matching = |matches: &dyn Fn(&ty::ParamTy) -> bool| {
+            predicate_substs.types().find_map(|ty| {
+                ty.walk().find_map(|arg| {
+                    if let ty::GenericArgKind::Type(ty) = arg.unpack()
+                        && let ty::Param(param_ty) = ty.kind()
+                        && matches(param_ty)
+                    {
+                        Some(arg)
+                    } else {
+                        None
+                    }
+                })
+            })
+        };
+
+        // Prefer generics that are local to the fn item, since these are likely
+        // to be the cause of the unsatisfied predicate.
+        let mut param_to_point_at = find_param_matching(&|param_ty| {
+            self.tcx.parent(generics.type_param(param_ty, self.tcx).def_id) == def_id
+        });
+        // Fall back to generic that isn't local to the fn item. This will come
+        // from a trait or impl, for example.
+        let mut fallback_param_to_point_at = find_param_matching(&|param_ty| {
+            self.tcx.parent(generics.type_param(param_ty, self.tcx).def_id) != def_id
+                && param_ty.name != rustc_span::symbol::kw::SelfUpper
+        });
+        // Finally, the `Self` parameter is possibly the reason that the predicate
+        // is unsatisfied. This is less likely to be true for methods, because
+        // method probe means that we already kinda check that the predicates due
+        // to the `Self` type are true.
+        let mut self_param_to_point_at =
+            find_param_matching(&|param_ty| param_ty.name == rustc_span::symbol::kw::SelfUpper);
+
+        // Finally, for ambiguity-related errors, we actually want to look
+        // for a parameter that is the source of the inference type left
+        // over in this predicate.
+        if let traits::FulfillmentErrorCode::CodeAmbiguity = error.code {
+            fallback_param_to_point_at = None;
+            self_param_to_point_at = None;
+            param_to_point_at =
+                self.find_ambiguous_parameter_in(def_id, error.root_obligation.predicate);
+        }
+
+        if self.closure_span_overlaps_error(error, expr.span) {
+            return false;
+        }
+
+        match &expr.kind {
+            hir::ExprKind::Path(qpath) => {
+                if let hir::Node::Expr(hir::Expr {
+                    kind: hir::ExprKind::Call(callee, args),
+                    hir_id: call_hir_id,
+                    span: call_span,
+                    ..
+                }) = hir.get(hir.get_parent_node(expr.hir_id))
+                    && callee.hir_id == expr.hir_id
+                {
+                    if self.closure_span_overlaps_error(error, *call_span) {
+                        return false;
+                    }
+
+                    for param in
+                        [param_to_point_at, fallback_param_to_point_at, self_param_to_point_at]
+                        .into_iter()
+                        .flatten()
+                    {
+                        if self.point_at_arg_if_possible(
+                                error,
+                                def_id,
+                                param,
+                                *call_hir_id,
+                                callee.span,
+                                args,
+                            )
+                        {
+                            return true;
+                        }
+                    }
+                    // Notably, we only point to params that are local to the
+                    // item we're checking, since those are the ones we are able
+                    // to look in the final `hir::PathSegment` for. Everything else
+                    // would require a deeper search into the `qpath` than I think
+                    // is worthwhile.
+                    if let Some(param_to_point_at) = param_to_point_at
+                        && self.point_at_path_if_possible(error, def_id, param_to_point_at, qpath)
+                    {
+                        return true;
+                    }
                 }
             }
-            let self_: ty::subst::GenericArg<'_> =
-                match unpeel_to_top(error.obligation.cause.code()) {
-                    ObligationCauseCode::BuiltinDerivedObligation(code)
-                    | ObligationCauseCode::DerivedObligation(code) => {
-                        code.parent_trait_pred.self_ty().skip_binder().into()
-                    }
-                    ObligationCauseCode::ImplDerivedObligation(code) => {
-                        code.derived.parent_trait_pred.self_ty().skip_binder().into()
+            hir::ExprKind::MethodCall(segment, args, ..) => {
+                for param in [param_to_point_at, fallback_param_to_point_at, self_param_to_point_at]
+                    .into_iter()
+                    .flatten()
+                {
+                    if self.point_at_arg_if_possible(
+                        error,
+                        def_id,
+                        param,
+                        hir_id,
+                        segment.ident.span,
+                        args,
+                    ) {
+                        return true;
                     }
-                    _ => match error.obligation.predicate.kind().skip_binder() {
-                        ty::PredicateKind::Trait(predicate) => predicate.self_ty().into(),
-                        ty::PredicateKind::Projection(predicate) => {
-                            predicate.projection_ty.self_ty().into()
+                }
+                if let Some(param_to_point_at) = param_to_point_at
+                    && self.point_at_generic_if_possible(error, def_id, param_to_point_at, segment)
+                {
+                    return true;
+                }
+            }
+            hir::ExprKind::Struct(qpath, fields, ..) => {
+                if let Res::Def(DefKind::Struct | DefKind::Variant, variant_def_id) =
+                    self.typeck_results.borrow().qpath_res(qpath, hir_id)
+                {
+                    for param in
+                        [param_to_point_at, fallback_param_to_point_at, self_param_to_point_at]
+                    {
+                        if let Some(param) = param
+                            && self.point_at_field_if_possible(
+                                error,
+                                def_id,
+                                param,
+                                variant_def_id,
+                                fields,
+                            )
+                        {
+                            return true;
                         }
-                        _ => continue,
-                    },
-                };
-            let self_ = self.resolve_vars_if_possible(self_);
-            let ty_matches_self = |ty: Ty<'tcx>| ty.walk().any(|arg| arg == self_);
-
-            let typeck_results = self.typeck_results.borrow();
-
-            for (idx, arg) in args.iter().enumerate() {
-                // Don't adjust the span if we already have a more precise span
-                // within one of the args.
-                if arg.span.contains(error.obligation.cause.span) {
-                    let references_arg =
-                        typeck_results.expr_ty_opt(arg).map_or(false, &ty_matches_self)
-                            || expected_tys.get(idx).copied().map_or(false, &ty_matches_self);
-                    if references_arg && !arg.span.from_expansion() {
-                        error.obligation.cause.map_code(|parent_code| {
-                            ObligationCauseCode::FunctionArgumentObligation {
-                                arg_hir_id: args[idx].hir_id,
-                                call_hir_id: expr.hir_id,
-                                parent_code,
-                            }
-                        })
                     }
-                    continue 'outer;
+                }
+                if let Some(param_to_point_at) = param_to_point_at
+                    && self.point_at_path_if_possible(error, def_id, param_to_point_at, qpath)
+                {
+                    return true;
                 }
             }
+            _ => {}
+        }
 
-            // Collect the argument position for all arguments that could have caused this
-            // `FulfillmentError`.
-            let mut referenced_in: Vec<_> = std::iter::zip(expected_tys, args)
-                .enumerate()
-                .flat_map(|(idx, (expected_ty, arg))| {
-                    if let Some(arg_ty) = typeck_results.expr_ty_opt(arg) {
-                        vec![(idx, arg_ty), (idx, *expected_ty)]
-                    } else {
-                        vec![]
-                    }
-                })
-                .filter_map(|(i, ty)| {
-                    let ty = self.resolve_vars_if_possible(ty);
-                    // We walk the argument type because the argument's type could have
-                    // been `Option<T>`, but the `FulfillmentError` references `T`.
-                    if ty_matches_self(ty) { Some(i) } else { None }
-                })
-                .collect();
+        false
+    }
 
-            // Both checked and coerced types could have matched, thus we need to remove
-            // duplicates.
+    fn closure_span_overlaps_error(
+        &self,
+        error: &traits::FulfillmentError<'tcx>,
+        span: Span,
+    ) -> bool {
+        if let traits::FulfillmentErrorCode::CodeSelectionError(
+            traits::SelectionError::OutputTypeParameterMismatch(_, expected, _),
+        ) = error.code
+            && let ty::Closure(def_id, _) | ty::Generator(def_id, ..) = expected.skip_binder().self_ty().kind()
+            && span.overlaps(self.tcx.def_span(*def_id))
+        {
+            true
+        } else {
+            false
+        }
+    }
 
-            // We sort primitive type usize here and can use unstable sort
-            referenced_in.sort_unstable();
-            referenced_in.dedup();
+    fn point_at_arg_if_possible(
+        &self,
+        error: &mut traits::FulfillmentError<'tcx>,
+        def_id: DefId,
+        param_to_point_at: ty::GenericArg<'tcx>,
+        call_hir_id: hir::HirId,
+        callee_span: Span,
+        args: &[hir::Expr<'tcx>],
+    ) -> bool {
+        let sig = self.tcx.fn_sig(def_id).skip_binder();
+        let args_referencing_param: Vec<_> = sig
+            .inputs()
+            .iter()
+            .enumerate()
+            .filter(|(_, ty)| find_param_in_ty(**ty, param_to_point_at))
+            .collect();
 
-            if let &[idx] = &referenced_in[..] {
-                // Do not point at the inside of a macro.
-                // That would often result in poor error messages.
-                if args[idx].span.from_expansion() {
-                    continue;
+        // If there's one field that references the given generic, great!
+        if let [(idx, _)] = args_referencing_param.as_slice() && let Some(arg) = args.get(*idx) {
+            error.obligation.cause.span = arg.span.find_ancestor_in_same_ctxt(error.obligation.cause.span).unwrap_or(arg.span);
+            error.obligation.cause.map_code(|parent_code| {
+                ObligationCauseCode::FunctionArgumentObligation {
+                    arg_hir_id: arg.hir_id,
+                    call_hir_id,
+                    parent_code,
                 }
-                // We make sure that only *one* argument matches the obligation failure
-                // and we assign the obligation's span to its expression's.
-                error.obligation.cause.span = args[idx].span;
-                error.obligation.cause.map_code(|parent_code| {
-                    ObligationCauseCode::FunctionArgumentObligation {
-                        arg_hir_id: args[idx].hir_id,
-                        call_hir_id: expr.hir_id,
-                        parent_code,
-                    }
-                });
-            } else if error.obligation.cause.span == call_sp {
-                // Make function calls point at the callee, not the whole thing.
-                if let hir::ExprKind::Call(callee, _) = expr.kind {
-                    error.obligation.cause.span = callee.span;
+            });
+            return true;
+        } else if args_referencing_param.len() > 0 {
+            // If more than one argument applies, then point to the callee span at least...
+            // We have chance to fix this up further in `point_at_generics_if_possible`
+            error.obligation.cause.span = callee_span;
+        }
+
+        false
+    }
+
+    fn point_at_field_if_possible(
+        &self,
+        error: &mut traits::FulfillmentError<'tcx>,
+        def_id: DefId,
+        param_to_point_at: ty::GenericArg<'tcx>,
+        variant_def_id: DefId,
+        expr_fields: &[hir::ExprField<'tcx>],
+    ) -> bool {
+        let def = self.tcx.adt_def(def_id);
+
+        let identity_substs = ty::InternalSubsts::identity_for_item(self.tcx, def_id);
+        let fields_referencing_param: Vec<_> = def
+            .variant_with_id(variant_def_id)
+            .fields
+            .iter()
+            .filter(|field| {
+                let field_ty = field.ty(self.tcx, identity_substs);
+                find_param_in_ty(field_ty, param_to_point_at)
+            })
+            .collect();
+
+        if let [field] = fields_referencing_param.as_slice() {
+            for expr_field in expr_fields {
+                // Look for the ExprField that matches the field, using the
+                // same rules that check_expr_struct uses for macro hygiene.
+                if self.tcx.adjust_ident(expr_field.ident, variant_def_id) == field.ident(self.tcx)
+                {
+                    error.obligation.cause.span = expr_field
+                        .expr
+                        .span
+                        .find_ancestor_in_same_ctxt(error.obligation.cause.span)
+                        .unwrap_or(expr_field.span);
+                    return true;
                 }
             }
         }
+
+        false
     }
 
-    /// Given a vec of evaluated `FulfillmentError`s and an `fn` call expression, we walk the
-    /// `PathSegment`s and resolve their type parameters to see if any of the `FulfillmentError`s
-    /// were caused by them. If they were, we point at the corresponding type argument's span
-    /// instead of the `fn` call path span.
-    fn point_at_type_arg_instead_of_call_if_possible(
+    fn point_at_path_if_possible(
         &self,
-        errors: &mut Vec<traits::FulfillmentError<'tcx>>,
-        call_expr: &'tcx hir::Expr<'tcx>,
-    ) {
-        if let hir::ExprKind::Call(path, _) = &call_expr.kind {
-            if let hir::ExprKind::Path(hir::QPath::Resolved(_, path)) = &path.kind {
-                for error in errors {
-                    let self_ty = match error.obligation.predicate.kind().skip_binder() {
-                        ty::PredicateKind::Trait(predicate) => predicate.self_ty(),
-                        ty::PredicateKind::Projection(predicate) => {
-                            predicate.projection_ty.self_ty()
-                        }
-                        _ => continue,
-                    };
-                    // If any of the type arguments in this path segment caused the
-                    // `FulfillmentError`, point at its span (#61860).
-                    for arg in path
-                        .segments
-                        .iter()
-                        .filter_map(|seg| seg.args.as_ref())
-                        .flat_map(|a| a.args.iter())
-                    {
-                        if let hir::GenericArg::Type(hir_ty) = &arg
-                            && let Some(ty) =
-                                self.typeck_results.borrow().node_type_opt(hir_ty.hir_id)
-                            && self.resolve_vars_if_possible(ty) == self_ty
-                        {
-                            error.obligation.cause.span = hir_ty.span;
-                            break;
-                        }
-                    }
+        error: &mut traits::FulfillmentError<'tcx>,
+        def_id: DefId,
+        param: ty::GenericArg<'tcx>,
+        qpath: &QPath<'tcx>,
+    ) -> bool {
+        match qpath {
+            hir::QPath::Resolved(_, path) => {
+                if let Some(segment) = path.segments.last()
+                    && self.point_at_generic_if_possible(error, def_id, param, segment)
+                {
+                    return true;
+                }
+            }
+            hir::QPath::TypeRelative(_, segment) => {
+                if self.point_at_generic_if_possible(error, def_id, param, segment) {
+                    return true;
+                }
+            }
+            _ => {}
+        }
+
+        false
+    }
+
+    fn point_at_generic_if_possible(
+        &self,
+        error: &mut traits::FulfillmentError<'tcx>,
+        def_id: DefId,
+        param_to_point_at: ty::GenericArg<'tcx>,
+        segment: &hir::PathSegment<'tcx>,
+    ) -> bool {
+        let own_substs = self
+            .tcx
+            .generics_of(def_id)
+            .own_substs(ty::InternalSubsts::identity_for_item(self.tcx, def_id));
+        let Some((index, _)) = own_substs
+            .iter()
+            .filter(|arg| matches!(arg.unpack(), ty::GenericArgKind::Type(_)))
+            .enumerate()
+            .find(|(_, arg)| **arg == param_to_point_at) else { return false };
+        let Some(arg) = segment
+            .args()
+            .args
+            .iter()
+            .filter(|arg| matches!(arg, hir::GenericArg::Type(_)))
+            .nth(index) else { return false; };
+        error.obligation.cause.span = arg
+            .span()
+            .find_ancestor_in_same_ctxt(error.obligation.cause.span)
+            .unwrap_or(arg.span());
+        true
+    }
+
+    fn find_ambiguous_parameter_in<T: TypeVisitable<'tcx>>(
+        &self,
+        item_def_id: DefId,
+        t: T,
+    ) -> Option<ty::GenericArg<'tcx>> {
+        struct FindAmbiguousParameter<'a, 'tcx>(&'a FnCtxt<'a, 'tcx>, DefId);
+        impl<'tcx> TypeVisitor<'tcx> for FindAmbiguousParameter<'_, 'tcx> {
+            type BreakTy = ty::GenericArg<'tcx>;
+            fn visit_ty(&mut self, ty: Ty<'tcx>) -> std::ops::ControlFlow<Self::BreakTy> {
+                if let Some(origin) = self.0.type_var_origin(ty)
+                    && let TypeVariableOriginKind::TypeParameterDefinition(_, Some(def_id)) =
+                        origin.kind
+                    && let generics = self.0.tcx.generics_of(self.1)
+                    && let Some(index) = generics.param_def_id_to_index(self.0.tcx, def_id)
+                    && let Some(subst) = ty::InternalSubsts::identity_for_item(self.0.tcx, self.1)
+                        .get(index as usize)
+                {
+                    ControlFlow::Break(*subst)
+                } else {
+                    ty.super_visit_with(self)
                 }
             }
         }
+        t.visit_with(&mut FindAmbiguousParameter(self, item_def_id)).break_value()
     }
 
     fn label_fn_like(
@@ -1864,14 +2075,17 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     let new_def_id = self.probe(|_| {
                         let trait_ref = ty::TraitRef::new(
                             call_kind.to_def_id(self.tcx),
-                            self.tcx.mk_substs([
-                                ty::GenericArg::from(callee_ty),
-                                self.next_ty_var(TypeVariableOrigin {
-                                    kind: TypeVariableOriginKind::MiscVariable,
-                                    span: rustc_span::DUMMY_SP,
-                                })
-                                .into(),
-                            ].into_iter()),
+                            self.tcx.mk_substs(
+                                [
+                                    ty::GenericArg::from(callee_ty),
+                                    self.next_ty_var(TypeVariableOrigin {
+                                        kind: TypeVariableOriginKind::MiscVariable,
+                                        span: rustc_span::DUMMY_SP,
+                                    })
+                                    .into(),
+                                ]
+                                .into_iter(),
+                            ),
                         );
                         let obligation = traits::Obligation::new(
                             traits::ObligationCause::dummy(),
@@ -1886,7 +2100,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             Ok(Some(traits::ImplSource::UserDefined(impl_source))) => {
                                 Some(impl_source.impl_def_id)
                             }
-                            _ => None
+                            _ => None,
                         }
                     });
                     if let Some(new_def_id) = new_def_id {
@@ -1940,3 +2154,23 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 }
+
+fn find_param_in_ty<'tcx>(ty: Ty<'tcx>, param_to_point_at: ty::GenericArg<'tcx>) -> bool {
+    let mut walk = ty.walk();
+    while let Some(arg) = walk.next() {
+        if arg == param_to_point_at {
+            return true;
+        } else if let ty::GenericArgKind::Type(ty) = arg.unpack()
+            && let ty::Projection(..) = ty.kind()
+        {
+            // This logic may seem a bit strange, but typically when
+            // we have a projection type in a function signature, the
+            // argument that's being passed into that signature is
+            // not actually constraining that projection's substs in
+            // a meaningful way. So we skip it, and see improvements
+            // in some UI tests.
+            walk.skip_current_subtree();
+        }
+    }
+    false
+}
diff --git a/compiler/rustc_typeck/src/check/method/confirm.rs b/compiler/rustc_typeck/src/check/method/confirm.rs
index 2c89b63ae84f8..59fd5c315ae63 100644
--- a/compiler/rustc_typeck/src/check/method/confirm.rs
+++ b/compiler/rustc_typeck/src/check/method/confirm.rs
@@ -491,7 +491,19 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> {
         // so we just call `predicates_for_generics` directly to avoid redoing work.
         // `self.add_required_obligations(self.span, def_id, &all_substs);`
         for obligation in traits::predicates_for_generics(
-            traits::ObligationCause::new(self.span, self.body_id, traits::ItemObligation(def_id)),
+            |idx, span| {
+                let code = if span.is_dummy() {
+                    ObligationCauseCode::ExprItemObligation(def_id, self.call_expr.hir_id, idx)
+                } else {
+                    ObligationCauseCode::ExprBindingObligation(
+                        def_id,
+                        span,
+                        self.call_expr.hir_id,
+                        idx,
+                    )
+                };
+                traits::ObligationCause::new(self.span, self.body_id, code)
+            },
             self.param_env,
             method_predicates,
         ) {
diff --git a/compiler/rustc_typeck/src/check/method/mod.rs b/compiler/rustc_typeck/src/check/method/mod.rs
index 0e678c41f8b40..de26a9e56e2d6 100644
--- a/compiler/rustc_typeck/src/check/method/mod.rs
+++ b/compiler/rustc_typeck/src/check/method/mod.rs
@@ -534,7 +534,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         } else {
             traits::ObligationCause::misc(span, self.body_id)
         };
-        obligations.extend(traits::predicates_for_generics(cause.clone(), self.param_env, bounds));
+        let predicates_cause = cause.clone();
+        obligations.extend(traits::predicates_for_generics(
+            move |_, _| predicates_cause.clone(),
+            self.param_env,
+            bounds,
+        ));
 
         // Also add an obligation for the method type being well-formed.
         let method_ty = tcx.mk_fn_ptr(ty::Binder::dummy(fn_sig));
diff --git a/compiler/rustc_typeck/src/check/method/probe.rs b/compiler/rustc_typeck/src/check/method/probe.rs
index efe15fec7cbfa..d9870060a40bb 100644
--- a/compiler/rustc_typeck/src/check/method/probe.rs
+++ b/compiler/rustc_typeck/src/check/method/probe.rs
@@ -1514,8 +1514,11 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
                         traits::normalize(selcx, self.param_env, cause.clone(), impl_bounds);
 
                     // Convert the bounds into obligations.
-                    let impl_obligations =
-                        traits::predicates_for_generics(cause, self.param_env, impl_bounds);
+                    let impl_obligations = traits::predicates_for_generics(
+                        move |_, _| cause.clone(),
+                        self.param_env,
+                        impl_bounds,
+                    );
 
                     let candidate_obligations = impl_obligations
                         .chain(norm_obligations.into_iter())
diff --git a/compiler/rustc_typeck/src/errors.rs b/compiler/rustc_typeck/src/errors.rs
index 8b1cb8d1c939a..2214fc2ced883 100644
--- a/compiler/rustc_typeck/src/errors.rs
+++ b/compiler/rustc_typeck/src/errors.rs
@@ -6,7 +6,7 @@ use rustc_session::{parse::ParseSess, SessionDiagnostic};
 use rustc_span::{symbol::Ident, Span, Symbol};
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::field_multiply_specified_in_initializer, code = "E0062")]
+#[diag(typeck::field_multiply_specified_in_initializer, code = "E0062")]
 pub struct FieldMultiplySpecifiedInInitializer {
     #[primary_span]
     #[label]
@@ -17,7 +17,7 @@ pub struct FieldMultiplySpecifiedInInitializer {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::unrecognized_atomic_operation, code = "E0092")]
+#[diag(typeck::unrecognized_atomic_operation, code = "E0092")]
 pub struct UnrecognizedAtomicOperation<'a> {
     #[primary_span]
     #[label]
@@ -26,7 +26,7 @@ pub struct UnrecognizedAtomicOperation<'a> {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::wrong_number_of_generic_arguments_to_intrinsic, code = "E0094")]
+#[diag(typeck::wrong_number_of_generic_arguments_to_intrinsic, code = "E0094")]
 pub struct WrongNumberOfGenericArgumentsToIntrinsic<'a> {
     #[primary_span]
     #[label]
@@ -37,7 +37,7 @@ pub struct WrongNumberOfGenericArgumentsToIntrinsic<'a> {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::unrecognized_intrinsic_function, code = "E0093")]
+#[diag(typeck::unrecognized_intrinsic_function, code = "E0093")]
 pub struct UnrecognizedIntrinsicFunction {
     #[primary_span]
     #[label]
@@ -46,7 +46,7 @@ pub struct UnrecognizedIntrinsicFunction {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::lifetimes_or_bounds_mismatch_on_trait, code = "E0195")]
+#[diag(typeck::lifetimes_or_bounds_mismatch_on_trait, code = "E0195")]
 pub struct LifetimesOrBoundsMismatchOnTrait {
     #[primary_span]
     #[label]
@@ -58,7 +58,7 @@ pub struct LifetimesOrBoundsMismatchOnTrait {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::drop_impl_on_wrong_item, code = "E0120")]
+#[diag(typeck::drop_impl_on_wrong_item, code = "E0120")]
 pub struct DropImplOnWrongItem {
     #[primary_span]
     #[label]
@@ -66,7 +66,7 @@ pub struct DropImplOnWrongItem {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::field_already_declared, code = "E0124")]
+#[diag(typeck::field_already_declared, code = "E0124")]
 pub struct FieldAlreadyDeclared {
     pub field_name: Ident,
     #[primary_span]
@@ -77,7 +77,7 @@ pub struct FieldAlreadyDeclared {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::copy_impl_on_type_with_dtor, code = "E0184")]
+#[diag(typeck::copy_impl_on_type_with_dtor, code = "E0184")]
 pub struct CopyImplOnTypeWithDtor {
     #[primary_span]
     #[label]
@@ -85,14 +85,14 @@ pub struct CopyImplOnTypeWithDtor {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::multiple_relaxed_default_bounds, code = "E0203")]
+#[diag(typeck::multiple_relaxed_default_bounds, code = "E0203")]
 pub struct MultipleRelaxedDefaultBounds {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::copy_impl_on_non_adt, code = "E0206")]
+#[diag(typeck::copy_impl_on_non_adt, code = "E0206")]
 pub struct CopyImplOnNonAdt {
     #[primary_span]
     #[label]
@@ -100,7 +100,7 @@ pub struct CopyImplOnNonAdt {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::trait_object_declared_with_no_traits, code = "E0224")]
+#[diag(typeck::trait_object_declared_with_no_traits, code = "E0224")]
 pub struct TraitObjectDeclaredWithNoTraits {
     #[primary_span]
     pub span: Span,
@@ -109,14 +109,14 @@ pub struct TraitObjectDeclaredWithNoTraits {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0227")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0227")]
 pub struct AmbiguousLifetimeBound {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::assoc_type_binding_not_allowed, code = "E0229")]
+#[diag(typeck::assoc_type_binding_not_allowed, code = "E0229")]
 pub struct AssocTypeBindingNotAllowed {
     #[primary_span]
     #[label]
@@ -124,14 +124,14 @@ pub struct AssocTypeBindingNotAllowed {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::functional_record_update_on_non_struct, code = "E0436")]
+#[diag(typeck::functional_record_update_on_non_struct, code = "E0436")]
 pub struct FunctionalRecordUpdateOnNonStruct {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::typeof_reserved_keyword_used, code = "E0516")]
+#[diag(typeck::typeof_reserved_keyword_used, code = "E0516")]
 pub struct TypeofReservedKeywordUsed<'tcx> {
     pub ty: Ty<'tcx>,
     #[primary_span]
@@ -142,7 +142,7 @@ pub struct TypeofReservedKeywordUsed<'tcx> {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::return_stmt_outside_of_fn_body, code = "E0572")]
+#[diag(typeck::return_stmt_outside_of_fn_body, code = "E0572")]
 pub struct ReturnStmtOutsideOfFnBody {
     #[primary_span]
     pub span: Span,
@@ -153,14 +153,14 @@ pub struct ReturnStmtOutsideOfFnBody {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::yield_expr_outside_of_generator, code = "E0627")]
+#[diag(typeck::yield_expr_outside_of_generator, code = "E0627")]
 pub struct YieldExprOutsideOfGenerator {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::struct_expr_non_exhaustive, code = "E0639")]
+#[diag(typeck::struct_expr_non_exhaustive, code = "E0639")]
 pub struct StructExprNonExhaustive {
     #[primary_span]
     pub span: Span,
@@ -168,14 +168,14 @@ pub struct StructExprNonExhaustive {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::method_call_on_unknown_type, code = "E0699")]
+#[diag(typeck::method_call_on_unknown_type, code = "E0699")]
 pub struct MethodCallOnUnknownType {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::value_of_associated_struct_already_specified, code = "E0719")]
+#[diag(typeck::value_of_associated_struct_already_specified, code = "E0719")]
 pub struct ValueOfAssociatedStructAlreadySpecified {
     #[primary_span]
     #[label]
@@ -187,7 +187,7 @@ pub struct ValueOfAssociatedStructAlreadySpecified {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::address_of_temporary_taken, code = "E0745")]
+#[diag(typeck::address_of_temporary_taken, code = "E0745")]
 pub struct AddressOfTemporaryTaken {
     #[primary_span]
     #[label]
@@ -233,7 +233,7 @@ pub enum ExpectedReturnTypeLabel<'tcx> {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::unconstrained_opaque_type)]
+#[diag(typeck::unconstrained_opaque_type)]
 #[note]
 pub struct UnconstrainedOpaqueType {
     #[primary_span]
@@ -309,7 +309,7 @@ impl<'a> SessionDiagnostic<'a> for MissingTypeParams {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::manual_implementation, code = "E0183")]
+#[diag(typeck::manual_implementation, code = "E0183")]
 #[help]
 pub struct ManualImplementation {
     #[primary_span]
@@ -319,21 +319,21 @@ pub struct ManualImplementation {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::substs_on_overridden_impl)]
+#[diag(typeck::substs_on_overridden_impl)]
 pub struct SubstsOnOverriddenImpl {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(LintDiagnostic)]
-#[lint(typeck::unused_extern_crate)]
+#[diag(typeck::unused_extern_crate)]
 pub struct UnusedExternCrate {
     #[suggestion(applicability = "machine-applicable", code = "")]
     pub span: Span,
 }
 
 #[derive(LintDiagnostic)]
-#[lint(typeck::extern_crate_not_idiomatic)]
+#[diag(typeck::extern_crate_not_idiomatic)]
 pub struct ExternCrateNotIdiomatic {
     #[suggestion_short(applicability = "machine-applicable", code = "{suggestion_code}")]
     pub span: Span,
@@ -342,7 +342,7 @@ pub struct ExternCrateNotIdiomatic {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::expected_used_symbol)]
+#[diag(typeck::expected_used_symbol)]
 pub struct ExpectedUsedSymbol {
     #[primary_span]
     pub span: Span,
diff --git a/library/alloc/src/alloc/tests.rs b/library/alloc/src/alloc/tests.rs
index 7d560964d85be..b2f0194599b28 100644
--- a/library/alloc/src/alloc/tests.rs
+++ b/library/alloc/src/alloc/tests.rs
@@ -15,7 +15,7 @@ fn allocate_zeroed() {
         let end = i.add(layout.size());
         while i < end {
             assert_eq!(*i, 0);
-            i = i.offset(1);
+            i = i.add(1);
         }
         Global.deallocate(ptr.as_non_null_ptr(), layout);
     }
diff --git a/library/alloc/src/collections/vec_deque/mod.rs b/library/alloc/src/collections/vec_deque/mod.rs
index 4d895d83745b2..57ab74e01590b 100644
--- a/library/alloc/src/collections/vec_deque/mod.rs
+++ b/library/alloc/src/collections/vec_deque/mod.rs
@@ -2447,8 +2447,8 @@ impl<T, A: Allocator> VecDeque<T, A> {
                     let mut right_offset = 0;
                     for i in left_edge..right_edge {
                         right_offset = (i - left_edge) % (cap - right_edge);
-                        let src: isize = (right_edge + right_offset) as isize;
-                        ptr::swap(buf.add(i), buf.offset(src));
+                        let src = right_edge + right_offset;
+                        ptr::swap(buf.add(i), buf.add(src));
                     }
                     let n_ops = right_edge - left_edge;
                     left_edge += n_ops;
diff --git a/library/alloc/src/ffi/c_str.rs b/library/alloc/src/ffi/c_str.rs
index ae61b1f1e8ed5..be21d8c722d78 100644
--- a/library/alloc/src/ffi/c_str.rs
+++ b/library/alloc/src/ffi/c_str.rs
@@ -436,9 +436,9 @@ impl CString {
     ///
     /// unsafe {
     ///     assert_eq!(b'f', *ptr as u8);
-    ///     assert_eq!(b'o', *ptr.offset(1) as u8);
-    ///     assert_eq!(b'o', *ptr.offset(2) as u8);
-    ///     assert_eq!(b'\0', *ptr.offset(3) as u8);
+    ///     assert_eq!(b'o', *ptr.add(1) as u8);
+    ///     assert_eq!(b'o', *ptr.add(2) as u8);
+    ///     assert_eq!(b'\0', *ptr.add(3) as u8);
     ///
     ///     // retake pointer to free memory
     ///     let _ = CString::from_raw(ptr);
diff --git a/library/alloc/src/slice.rs b/library/alloc/src/slice.rs
index 63d4d94529008..5733124ec7565 100644
--- a/library/alloc/src/slice.rs
+++ b/library/alloc/src/slice.rs
@@ -1024,7 +1024,7 @@ where
             // Consume the greater side.
             // If equal, prefer the right run to maintain stability.
             unsafe {
-                let to_copy = if is_less(&*right.offset(-1), &*left.offset(-1)) {
+                let to_copy = if is_less(&*right.sub(1), &*left.sub(1)) {
                     decrement_and_get(left)
                 } else {
                     decrement_and_get(right)
@@ -1038,12 +1038,12 @@ where
 
     unsafe fn get_and_increment<T>(ptr: &mut *mut T) -> *mut T {
         let old = *ptr;
-        *ptr = unsafe { ptr.offset(1) };
+        *ptr = unsafe { ptr.add(1) };
         old
     }
 
     unsafe fn decrement_and_get<T>(ptr: &mut *mut T) -> *mut T {
-        *ptr = unsafe { ptr.offset(-1) };
+        *ptr = unsafe { ptr.sub(1) };
         *ptr
     }
 
diff --git a/library/alloc/src/vec/in_place_collect.rs b/library/alloc/src/vec/in_place_collect.rs
index 55dcb84ad16f9..b211421b20270 100644
--- a/library/alloc/src/vec/in_place_collect.rs
+++ b/library/alloc/src/vec/in_place_collect.rs
@@ -267,7 +267,7 @@ where
             // one slot in the underlying storage will have been freed up and we can immediately
             // write back the result.
             unsafe {
-                let dst = dst_buf.offset(i as isize);
+                let dst = dst_buf.add(i);
                 debug_assert!(dst as *const _ <= end, "InPlaceIterable contract violation");
                 ptr::write(dst, self.__iterator_get_unchecked(i));
                 // Since this executes user code which can panic we have to bump the pointer
diff --git a/library/alloc/src/vec/into_iter.rs b/library/alloc/src/vec/into_iter.rs
index 1b483e3fc7793..e02ad391a595f 100644
--- a/library/alloc/src/vec/into_iter.rs
+++ b/library/alloc/src/vec/into_iter.rs
@@ -160,7 +160,7 @@ impl<T, A: Allocator> Iterator for IntoIter<T, A> {
             Some(unsafe { mem::zeroed() })
         } else {
             let old = self.ptr;
-            self.ptr = unsafe { self.ptr.offset(1) };
+            self.ptr = unsafe { self.ptr.add(1) };
 
             Some(unsafe { ptr::read(old) })
         }
@@ -272,7 +272,7 @@ impl<T, A: Allocator> DoubleEndedIterator for IntoIter<T, A> {
             // Make up a value of this ZST.
             Some(unsafe { mem::zeroed() })
         } else {
-            self.end = unsafe { self.end.offset(-1) };
+            self.end = unsafe { self.end.sub(1) };
 
             Some(unsafe { ptr::read(self.end) })
         }
@@ -288,7 +288,7 @@ impl<T, A: Allocator> DoubleEndedIterator for IntoIter<T, A> {
             }
         } else {
             // SAFETY: same as for advance_by()
-            self.end = unsafe { self.end.offset(step_size.wrapping_neg() as isize) };
+            self.end = unsafe { self.end.sub(step_size) };
         }
         let to_drop = ptr::slice_from_raw_parts_mut(self.end as *mut T, step_size);
         // SAFETY: same as for advance_by()
diff --git a/library/alloc/src/vec/mod.rs b/library/alloc/src/vec/mod.rs
index fa9f2131c0c1d..cea943602f770 100644
--- a/library/alloc/src/vec/mod.rs
+++ b/library/alloc/src/vec/mod.rs
@@ -542,8 +542,8 @@ impl<T> Vec<T> {
     ///
     /// unsafe {
     ///     // Overwrite memory with 4, 5, 6
-    ///     for i in 0..len as isize {
-    ///         ptr::write(p.offset(i), 4 + i);
+    ///     for i in 0..len {
+    ///         ptr::write(p.add(i), 4 + i);
     ///     }
     ///
     ///     // Put everything back together into a Vec
@@ -702,8 +702,8 @@ impl<T, A: Allocator> Vec<T, A> {
     ///
     /// unsafe {
     ///     // Overwrite memory with 4, 5, 6
-    ///     for i in 0..len as isize {
-    ///         ptr::write(p.offset(i), 4 + i);
+    ///     for i in 0..len {
+    ///         ptr::write(p.add(i), 4 + i);
     ///     }
     ///
     ///     // Put everything back together into a Vec
@@ -1393,7 +1393,7 @@ impl<T, A: Allocator> Vec<T, A> {
                 if index < len {
                     // Shift everything over to make space. (Duplicating the
                     // `index`th element into two consecutive places.)
-                    ptr::copy(p, p.offset(1), len - index);
+                    ptr::copy(p, p.add(1), len - index);
                 } else if index == len {
                     // No elements need shifting.
                 } else {
@@ -1455,7 +1455,7 @@ impl<T, A: Allocator> Vec<T, A> {
                 ret = ptr::read(ptr);
 
                 // Shift everything down to fill in that spot.
-                ptr::copy(ptr.offset(1), ptr, len - index - 1);
+                ptr::copy(ptr.add(1), ptr, len - index - 1);
             }
             self.set_len(len - 1);
             ret
@@ -2408,7 +2408,7 @@ impl<T, A: Allocator> Vec<T, A> {
             // Write all elements except the last one
             for _ in 1..n {
                 ptr::write(ptr, value.next());
-                ptr = ptr.offset(1);
+                ptr = ptr.add(1);
                 // Increment the length in every step in case next() panics
                 local_len.increment_len(1);
             }
diff --git a/library/alloc/src/vec/spec_extend.rs b/library/alloc/src/vec/spec_extend.rs
index 506ee0ecfa279..1ea9c827afd70 100644
--- a/library/alloc/src/vec/spec_extend.rs
+++ b/library/alloc/src/vec/spec_extend.rs
@@ -39,7 +39,7 @@ where
                 let mut local_len = SetLenOnDrop::new(&mut self.len);
                 iterator.for_each(move |element| {
                     ptr::write(ptr, element);
-                    ptr = ptr.offset(1);
+                    ptr = ptr.add(1);
                     // Since the loop executes user code which can panic we have to bump the pointer
                     // after each step.
                     // NB can't overflow since we would have had to alloc the address space
diff --git a/library/alloc/tests/str.rs b/library/alloc/tests/str.rs
index 7379569dd68fe..e30329aa1cb6c 100644
--- a/library/alloc/tests/str.rs
+++ b/library/alloc/tests/str.rs
@@ -1010,11 +1010,11 @@ fn test_as_bytes_fail() {
 fn test_as_ptr() {
     let buf = "hello".as_ptr();
     unsafe {
-        assert_eq!(*buf.offset(0), b'h');
-        assert_eq!(*buf.offset(1), b'e');
-        assert_eq!(*buf.offset(2), b'l');
-        assert_eq!(*buf.offset(3), b'l');
-        assert_eq!(*buf.offset(4), b'o');
+        assert_eq!(*buf.add(0), b'h');
+        assert_eq!(*buf.add(1), b'e');
+        assert_eq!(*buf.add(2), b'l');
+        assert_eq!(*buf.add(3), b'l');
+        assert_eq!(*buf.add(4), b'o');
     }
 }
 
diff --git a/library/core/src/intrinsics.rs b/library/core/src/intrinsics.rs
index 15467e0191dbf..3d7b875eac15d 100644
--- a/library/core/src/intrinsics.rs
+++ b/library/core/src/intrinsics.rs
@@ -2209,9 +2209,9 @@ pub(crate) fn is_nonoverlapping<T>(src: *const T, dst: *const T, count: usize) -
 ///     dst.reserve(src_len);
 ///
 ///     unsafe {
-///         // The call to offset is always safe because `Vec` will never
+///         // The call to add is always safe because `Vec` will never
 ///         // allocate more than `isize::MAX` bytes.
-///         let dst_ptr = dst.as_mut_ptr().offset(dst_len as isize);
+///         let dst_ptr = dst.as_mut_ptr().add(dst_len);
 ///         let src_ptr = src.as_ptr();
 ///
 ///         // Truncate `src` without dropping its contents. We do this first,
diff --git a/library/core/src/num/f32.rs b/library/core/src/num/f32.rs
index 23c46f1a74a31..efa434f239266 100644
--- a/library/core/src/num/f32.rs
+++ b/library/core/src/num/f32.rs
@@ -1282,15 +1282,14 @@ impl f32 {
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[stable(feature = "clamp", since = "1.50.0")]
     #[inline]
-    pub fn clamp(self, min: f32, max: f32) -> f32 {
+    pub fn clamp(mut self, min: f32, max: f32) -> f32 {
         assert!(min <= max);
-        let mut x = self;
-        if x < min {
-            x = min;
+        if self < min {
+            self = min;
         }
-        if x > max {
-            x = max;
+        if self > max {
+            self = max;
         }
-        x
+        self
     }
 }
diff --git a/library/core/src/num/f64.rs b/library/core/src/num/f64.rs
index b5c8241d2943d..9e4334fe01ad8 100644
--- a/library/core/src/num/f64.rs
+++ b/library/core/src/num/f64.rs
@@ -1280,15 +1280,14 @@ impl f64 {
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[stable(feature = "clamp", since = "1.50.0")]
     #[inline]
-    pub fn clamp(self, min: f64, max: f64) -> f64 {
+    pub fn clamp(mut self, min: f64, max: f64) -> f64 {
         assert!(min <= max);
-        let mut x = self;
-        if x < min {
-            x = min;
+        if self < min {
+            self = min;
         }
-        if x > max {
-            x = max;
+        if self > max {
+            self = max;
         }
-        x
+        self
     }
 }
diff --git a/library/core/src/slice/mod.rs b/library/core/src/slice/mod.rs
index e79d47c9f98cd..ea6a70c2f4e74 100644
--- a/library/core/src/slice/mod.rs
+++ b/library/core/src/slice/mod.rs
@@ -674,8 +674,9 @@ impl<T> [T] {
     /// assert!(v == [3, 2, 1]);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[rustc_const_unstable(feature = "const_reverse", issue = "100784")]
     #[inline]
-    pub fn reverse(&mut self) {
+    pub const fn reverse(&mut self) {
         let half_len = self.len() / 2;
         let Range { start, end } = self.as_mut_ptr_range();
 
@@ -698,9 +699,9 @@ impl<T> [T] {
         revswap(front_half, back_half, half_len);
 
         #[inline]
-        fn revswap<T>(a: &mut [T], b: &mut [T], n: usize) {
-            debug_assert_eq!(a.len(), n);
-            debug_assert_eq!(b.len(), n);
+        const fn revswap<T>(a: &mut [T], b: &mut [T], n: usize) {
+            debug_assert!(a.len() == n);
+            debug_assert!(b.len() == n);
 
             // Because this function is first compiled in isolation,
             // this check tells LLVM that the indexing below is
@@ -708,8 +709,10 @@ impl<T> [T] {
             // lengths of the slices are known -- it's removed.
             let (a, b) = (&mut a[..n], &mut b[..n]);
 
-            for i in 0..n {
+            let mut i = 0;
+            while i < n {
                 mem::swap(&mut a[i], &mut b[n - 1 - i]);
+                i += 1;
             }
         }
     }
@@ -2921,7 +2924,7 @@ impl<T> [T] {
                 let prev_ptr_write = ptr.add(next_write - 1);
                 if !same_bucket(&mut *ptr_read, &mut *prev_ptr_write) {
                     if next_read != next_write {
-                        let ptr_write = prev_ptr_write.offset(1);
+                        let ptr_write = prev_ptr_write.add(1);
                         mem::swap(&mut *ptr_read, &mut *ptr_write);
                     }
                     next_write += 1;
diff --git a/library/core/src/slice/sort.rs b/library/core/src/slice/sort.rs
index 6a201834b8e68..8b025da2a46ed 100644
--- a/library/core/src/slice/sort.rs
+++ b/library/core/src/slice/sort.rs
@@ -326,8 +326,8 @@ where
                 unsafe {
                     // Branchless comparison.
                     *end_l = i as u8;
-                    end_l = end_l.offset(!is_less(&*elem, pivot) as isize);
-                    elem = elem.offset(1);
+                    end_l = end_l.add(!is_less(&*elem, pivot) as usize);
+                    elem = elem.add(1);
                 }
             }
         }
@@ -352,9 +352,9 @@ where
                 //        Plus, `block_r` was asserted to be less than `BLOCK` and `elem` will therefore at most be pointing to the beginning of the slice.
                 unsafe {
                     // Branchless comparison.
-                    elem = elem.offset(-1);
+                    elem = elem.sub(1);
                     *end_r = i as u8;
-                    end_r = end_r.offset(is_less(&*elem, pivot) as isize);
+                    end_r = end_r.add(is_less(&*elem, pivot) as usize);
                 }
             }
         }
@@ -365,12 +365,12 @@ where
         if count > 0 {
             macro_rules! left {
                 () => {
-                    l.offset(*start_l as isize)
+                    l.add(*start_l as usize)
                 };
             }
             macro_rules! right {
                 () => {
-                    r.offset(-(*start_r as isize) - 1)
+                    r.sub((*start_r as usize) + 1)
                 };
             }
 
@@ -398,16 +398,16 @@ where
                 ptr::copy_nonoverlapping(right!(), left!(), 1);
 
                 for _ in 1..count {
-                    start_l = start_l.offset(1);
+                    start_l = start_l.add(1);
                     ptr::copy_nonoverlapping(left!(), right!(), 1);
-                    start_r = start_r.offset(1);
+                    start_r = start_r.add(1);
                     ptr::copy_nonoverlapping(right!(), left!(), 1);
                 }
 
                 ptr::copy_nonoverlapping(&tmp, right!(), 1);
                 mem::forget(tmp);
-                start_l = start_l.offset(1);
-                start_r = start_r.offset(1);
+                start_l = start_l.add(1);
+                start_r = start_r.add(1);
             }
         }
 
@@ -420,7 +420,7 @@ where
             // safe. Otherwise, the debug assertions in the `is_done` case guarantee that
             // `width(l, r) == block_l + block_r`, namely, that the block sizes have been adjusted to account
             // for the smaller number of remaining elements.
-            l = unsafe { l.offset(block_l as isize) };
+            l = unsafe { l.add(block_l) };
         }
 
         if start_r == end_r {
@@ -428,7 +428,7 @@ where
 
             // SAFETY: Same argument as [block-width-guarantee]. Either this is a full block `2*BLOCK`-wide,
             // or `block_r` has been adjusted for the last handful of elements.
-            r = unsafe { r.offset(-(block_r as isize)) };
+            r = unsafe { r.sub(block_r) };
         }
 
         if is_done {
@@ -457,9 +457,9 @@ where
             //  - `offsets_l` contains valid offsets into `v` collected during the partitioning of
             //    the last block, so the `l.offset` calls are valid.
             unsafe {
-                end_l = end_l.offset(-1);
-                ptr::swap(l.offset(*end_l as isize), r.offset(-1));
-                r = r.offset(-1);
+                end_l = end_l.sub(1);
+                ptr::swap(l.add(*end_l as usize), r.sub(1));
+                r = r.sub(1);
             }
         }
         width(v.as_mut_ptr(), r)
@@ -470,9 +470,9 @@ where
         while start_r < end_r {
             // SAFETY: See the reasoning in [remaining-elements-safety].
             unsafe {
-                end_r = end_r.offset(-1);
-                ptr::swap(l, r.offset(-(*end_r as isize) - 1));
-                l = l.offset(1);
+                end_r = end_r.sub(1);
+                ptr::swap(l, r.sub((*end_r as usize) + 1));
+                l = l.add(1);
             }
         }
         width(v.as_mut_ptr(), l)
diff --git a/library/core/src/str/validations.rs b/library/core/src/str/validations.rs
index 04bc665233e38..2acef432f2063 100644
--- a/library/core/src/str/validations.rs
+++ b/library/core/src/str/validations.rs
@@ -216,12 +216,12 @@ pub(super) const fn run_utf8_validation(v: &[u8]) -> Result<(), Utf8Error> {
                     // SAFETY: since `align - index` and `ascii_block_size` are
                     // multiples of `usize_bytes`, `block = ptr.add(index)` is
                     // always aligned with a `usize` so it's safe to dereference
-                    // both `block` and `block.offset(1)`.
+                    // both `block` and `block.add(1)`.
                     unsafe {
                         let block = ptr.add(index) as *const usize;
                         // break if there is a nonascii byte
                         let zu = contains_nonascii(*block);
-                        let zv = contains_nonascii(*block.offset(1));
+                        let zv = contains_nonascii(*block.add(1));
                         if zu || zv {
                             break;
                         }
diff --git a/library/core/src/sync/atomic.rs b/library/core/src/sync/atomic.rs
index 40ca9abd6bdc9..3c96290fc537e 100644
--- a/library/core/src/sync/atomic.rs
+++ b/library/core/src/sync/atomic.rs
@@ -1554,8 +1554,8 @@ impl<T> AtomicPtr<T> {
     /// Offsets the pointer's address by adding `val` *bytes*, returning the
     /// previous pointer.
     ///
-    /// This is equivalent to using [`wrapping_add`] and [`cast`] to atomically
-    /// perform `ptr = ptr.cast::<u8>().wrapping_add(val).cast::<T>()`.
+    /// This is equivalent to using [`wrapping_byte_add`] to atomically
+    /// perform `ptr = ptr.wrapping_byte_add(val)`.
     ///
     /// `fetch_byte_add` takes an [`Ordering`] argument which describes the
     /// memory ordering of this operation. All ordering modes are possible. Note
@@ -1565,8 +1565,7 @@ impl<T> AtomicPtr<T> {
     /// **Note**: This method is only available on platforms that support atomic
     /// operations on [`AtomicPtr`].
     ///
-    /// [`wrapping_add`]: pointer::wrapping_add
-    /// [`cast`]: pointer::cast
+    /// [`wrapping_byte_add`]: pointer::wrapping_byte_add
     ///
     /// # Examples
     ///
@@ -1591,8 +1590,8 @@ impl<T> AtomicPtr<T> {
     /// Offsets the pointer's address by subtracting `val` *bytes*, returning the
     /// previous pointer.
     ///
-    /// This is equivalent to using [`wrapping_sub`] and [`cast`] to atomically
-    /// perform `ptr = ptr.cast::<u8>().wrapping_sub(val).cast::<T>()`.
+    /// This is equivalent to using [`wrapping_byte_sub`] to atomically
+    /// perform `ptr = ptr.wrapping_byte_sub(val)`.
     ///
     /// `fetch_byte_sub` takes an [`Ordering`] argument which describes the
     /// memory ordering of this operation. All ordering modes are possible. Note
@@ -1602,8 +1601,7 @@ impl<T> AtomicPtr<T> {
     /// **Note**: This method is only available on platforms that support atomic
     /// operations on [`AtomicPtr`].
     ///
-    /// [`wrapping_sub`]: pointer::wrapping_sub
-    /// [`cast`]: pointer::cast
+    /// [`wrapping_byte_sub`]: pointer::wrapping_byte_sub
     ///
     /// # Examples
     ///
diff --git a/library/panic_abort/src/android.rs b/library/panic_abort/src/android.rs
index 18bb932f10ea9..0fd824f8a458d 100644
--- a/library/panic_abort/src/android.rs
+++ b/library/panic_abort/src/android.rs
@@ -42,7 +42,7 @@ pub(crate) unsafe fn android_set_abort_message(payload: *mut &mut dyn BoxMeUp) {
         return; // allocation failure
     }
     copy_nonoverlapping(msg.as_ptr(), buf as *mut u8, msg.len());
-    buf.offset(msg.len() as isize).write(0);
+    buf.add(msg.len()).write(0);
 
     let func = transmute::<usize, SetAbortMessageType>(func_addr);
     func(buf);
diff --git a/library/panic_unwind/src/dwarf/eh.rs b/library/panic_unwind/src/dwarf/eh.rs
index 7394feab82f22..9aa966b5063b1 100644
--- a/library/panic_unwind/src/dwarf/eh.rs
+++ b/library/panic_unwind/src/dwarf/eh.rs
@@ -75,7 +75,7 @@ pub unsafe fn find_eh_action(lsda: *const u8, context: &EHContext<'_>) -> Result
 
     let call_site_encoding = reader.read::<u8>();
     let call_site_table_length = reader.read_uleb128();
-    let action_table = reader.ptr.offset(call_site_table_length as isize);
+    let action_table = reader.ptr.add(call_site_table_length as usize);
     let ip = context.ip;
 
     if !USING_SJLJ_EXCEPTIONS {
diff --git a/library/std/src/os/unix/net/addr.rs b/library/std/src/os/unix/net/addr.rs
index 9aeae4b2cae69..bb313c7597b6c 100644
--- a/library/std/src/os/unix/net/addr.rs
+++ b/library/std/src/os/unix/net/addr.rs
@@ -329,7 +329,7 @@ impl SocketAddr {
 
             crate::ptr::copy_nonoverlapping(
                 namespace.as_ptr(),
-                addr.sun_path.as_mut_ptr().offset(1) as *mut u8,
+                addr.sun_path.as_mut_ptr().add(1) as *mut u8,
                 namespace.len(),
             );
             let len = (sun_path_offset(&addr) + 1 + namespace.len()) as libc::socklen_t;
diff --git a/library/std/src/process.rs b/library/std/src/process.rs
index d6cba7e7598f6..d91d4fa64caa5 100644
--- a/library/std/src/process.rs
+++ b/library/std/src/process.rs
@@ -169,15 +169,15 @@ use crate::sys_common::{AsInner, AsInnerMut, FromInner, IntoInner};
 pub struct Child {
     pub(crate) handle: imp::Process,
 
-    /// The handle for writing to the child's standard input (stdin), if it has
-    /// been captured. To avoid partially moving
-    /// the `child` and thus blocking yourself from calling
-    /// functions on `child` while using `stdin`,
-    /// you might find it helpful:
+    /// The handle for writing to the child's standard input (stdin), if it
+    /// has been captured. You might find it helpful to do
     ///
     /// ```compile_fail,E0425
     /// let stdin = child.stdin.take().unwrap();
     /// ```
+    ///
+    /// to avoid partially moving the `child` and thus blocking yourself from calling
+    /// functions on `child` while using `stdin`.
     #[stable(feature = "process", since = "1.0.0")]
     pub stdin: Option<ChildStdin>,
 
diff --git a/library/std/src/sys/sgx/abi/usercalls/tests.rs b/library/std/src/sys/sgx/abi/usercalls/tests.rs
index 4320f0bccd199..58b8eb215d73c 100644
--- a/library/std/src/sys/sgx/abi/usercalls/tests.rs
+++ b/library/std/src/sys/sgx/abi/usercalls/tests.rs
@@ -17,12 +17,12 @@ fn test_copy_to_userspace_function() {
             dst.copy_from_enclave(&[0u8; 100]);
 
             // Copy src[0..size] to dst + offset
-            unsafe { copy_to_userspace(src.as_ptr(), dst.as_mut_ptr().offset(offset), size) };
+            unsafe { copy_to_userspace(src.as_ptr(), dst.as_mut_ptr().add(offset), size) };
 
             // Verify copy
             for byte in 0..size {
                 unsafe {
-                    assert_eq!(*dst.as_ptr().offset(offset + byte as isize), src[byte as usize]);
+                    assert_eq!(*dst.as_ptr().add(offset + byte), src[byte as usize]);
                 }
             }
         }
diff --git a/library/std/src/sys/windows/alloc.rs b/library/std/src/sys/windows/alloc.rs
index fdc81cdea7dec..fe00c08aa6a9a 100644
--- a/library/std/src/sys/windows/alloc.rs
+++ b/library/std/src/sys/windows/alloc.rs
@@ -168,7 +168,7 @@ unsafe fn allocate(layout: Layout, zeroed: bool) -> *mut u8 {
         // SAFETY: Because the size and alignment of a header is <= `MIN_ALIGN` and `aligned`
         // is aligned to at least `MIN_ALIGN` and has at least `MIN_ALIGN` bytes of padding before
         // it, it is safe to write a header directly before it.
-        unsafe { ptr::write((aligned as *mut Header).offset(-1), Header(ptr)) };
+        unsafe { ptr::write((aligned as *mut Header).sub(1), Header(ptr)) };
 
         // SAFETY: The returned pointer does not point to the to the start of an allocated block,
         // but there is a header readable directly before it containing the location of the start
@@ -213,7 +213,7 @@ unsafe impl GlobalAlloc for System {
 
                 // SAFETY: Because of the contract of `System`, `ptr` is guaranteed to be non-null
                 // and have a header readable directly before it.
-                unsafe { ptr::read((ptr as *mut Header).offset(-1)).0 }
+                unsafe { ptr::read((ptr as *mut Header).sub(1)).0 }
             }
         };
 
diff --git a/library/std/src/sys/windows/fs.rs b/library/std/src/sys/windows/fs.rs
index aed082b3e0abf..1361b9c90c021 100644
--- a/library/std/src/sys/windows/fs.rs
+++ b/library/std/src/sys/windows/fs.rs
@@ -512,7 +512,7 @@ impl File {
                     ));
                 }
             };
-            let subst_ptr = path_buffer.offset(subst_off as isize);
+            let subst_ptr = path_buffer.add(subst_off.into());
             let mut subst = slice::from_raw_parts(subst_ptr, subst_len as usize);
             // Absolute paths start with an NT internal namespace prefix `\??\`
             // We should not let it leak through.
@@ -1345,10 +1345,10 @@ fn symlink_junction_inner(original: &Path, junction: &Path) -> io::Result<()> {
         let v = br"\??\";
         let v = v.iter().map(|x| *x as u16);
         for c in v.chain(original.as_os_str().encode_wide()) {
-            *buf.offset(i) = c;
+            *buf.add(i) = c;
             i += 1;
         }
-        *buf.offset(i) = 0;
+        *buf.add(i) = 0;
         i += 1;
         (*db).ReparseTag = c::IO_REPARSE_TAG_MOUNT_POINT;
         (*db).ReparseTargetMaximumLength = (i * 2) as c::WORD;
diff --git a/library/std/src/sys/windows/os.rs b/library/std/src/sys/windows/os.rs
index bcac996c024ec..352337ba32237 100644
--- a/library/std/src/sys/windows/os.rs
+++ b/library/std/src/sys/windows/os.rs
@@ -99,11 +99,11 @@ impl Iterator for Env {
                 }
                 let p = self.cur as *const u16;
                 let mut len = 0;
-                while *p.offset(len) != 0 {
+                while *p.add(len) != 0 {
                     len += 1;
                 }
-                let s = slice::from_raw_parts(p, len as usize);
-                self.cur = self.cur.offset(len + 1);
+                let s = slice::from_raw_parts(p, len);
+                self.cur = self.cur.add(len + 1);
 
                 // Windows allows environment variables to start with an equals
                 // symbol (in any other position, this is the separator between
diff --git a/src/bootstrap/bin/rustc.rs b/src/bootstrap/bin/rustc.rs
index 40a3cc6d12cac..bd5790d2ea882 100644
--- a/src/bootstrap/bin/rustc.rs
+++ b/src/bootstrap/bin/rustc.rs
@@ -25,10 +25,11 @@ use std::time::Instant;
 
 fn main() {
     let args = env::args_os().skip(1).collect::<Vec<_>>();
+    let arg = |name| args.windows(2).find(|args| args[0] == name).and_then(|args| args[1].to_str());
 
     // Detect whether or not we're a build script depending on whether --target
     // is passed (a bit janky...)
-    let target = args.windows(2).find(|w| &*w[0] == "--target").and_then(|w| w[1].to_str());
+    let target = arg("--target");
     let version = args.iter().find(|w| &**w == "-vV");
 
     let verbose = match env::var("RUSTC_VERBOSE") {
@@ -59,8 +60,7 @@ fn main() {
     cmd.args(&args).env(dylib_path_var(), env::join_paths(&dylib_path).unwrap());
 
     // Get the name of the crate we're compiling, if any.
-    let crate_name =
-        args.windows(2).find(|args| args[0] == "--crate-name").and_then(|args| args[1].to_str());
+    let crate_name = arg("--crate-name");
 
     if let Some(crate_name) = crate_name {
         if let Some(target) = env::var_os("RUSTC_TIME") {
@@ -106,6 +106,15 @@ fn main() {
         {
             cmd.arg("-C").arg("panic=abort");
         }
+
+        // `-Ztls-model=initial-exec` must not be applied to proc-macros, see
+        // issue https://github.com/rust-lang/rust/issues/100530
+        if env::var("RUSTC_TLS_MODEL_INITIAL_EXEC").is_ok()
+            && arg("--crate-type") != Some("proc-macro")
+            && !matches!(crate_name, Some("proc_macro2" | "quote" | "syn" | "synstructure"))
+        {
+            cmd.arg("-Ztls-model=initial-exec");
+        }
     } else {
         // FIXME(rust-lang/cargo#5754) we shouldn't be using special env vars
         // here, but rather Cargo should know what flags to pass rustc itself.
diff --git a/src/bootstrap/builder.rs b/src/bootstrap/builder.rs
index 0ab4824ac0a73..945299d2dcd3c 100644
--- a/src/bootstrap/builder.rs
+++ b/src/bootstrap/builder.rs
@@ -1850,7 +1850,7 @@ impl<'a> Builder<'a> {
         // so we can't use it by default in general, but we can use it for tools
         // and our own internal libraries.
         if !mode.must_support_dlopen() && !target.triple.starts_with("powerpc-") {
-            rustflags.arg("-Ztls-model=initial-exec");
+            cargo.env("RUSTC_TLS_MODEL_INITIAL_EXEC", "1");
         }
 
         if self.config.incremental {
diff --git a/src/librustdoc/Cargo.toml b/src/librustdoc/Cargo.toml
index ddaa7438e1778..cbdfea89efb8a 100644
--- a/src/librustdoc/Cargo.toml
+++ b/src/librustdoc/Cargo.toml
@@ -11,7 +11,7 @@ arrayvec = { version = "0.7", default-features = false }
 askama = { version = "0.11", default-features = false, features = ["config"] }
 atty = "0.2"
 pulldown-cmark = { version = "0.9.2", default-features = false }
-minifier = "0.2.1"
+minifier = "0.2.2"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 smallvec = "1.8.1"
diff --git a/src/librustdoc/clean/auto_trait.rs b/src/librustdoc/clean/auto_trait.rs
index a94520b121926..5441a7bd29ec0 100644
--- a/src/librustdoc/clean/auto_trait.rs
+++ b/src/librustdoc/clean/auto_trait.rs
@@ -551,13 +551,15 @@ where
                 }
                 WherePredicate::EqPredicate { lhs, rhs } => {
                     match lhs {
-                        Type::QPath { ref assoc, ref self_type, ref trait_, .. } => {
+                        Type::QPath(box QPathData {
+                            ref assoc, ref self_type, ref trait_, ..
+                        }) => {
                             let ty = &*self_type;
                             let mut new_trait = trait_.clone();
 
                             if self.is_fn_trait(trait_) && assoc.name == sym::Output {
                                 ty_to_fn
-                                    .entry(*ty.clone())
+                                    .entry(ty.clone())
                                     .and_modify(|e| {
                                         *e = (e.0.clone(), Some(rhs.ty().unwrap().clone()))
                                     })
@@ -582,7 +584,7 @@ where
                                 // to 'T: Iterator<Item=u8>'
                                 GenericArgs::AngleBracketed { ref mut bindings, .. } => {
                                     bindings.push(TypeBinding {
-                                        assoc: *assoc.clone(),
+                                        assoc: assoc.clone(),
                                         kind: TypeBindingKind::Equality { term: rhs },
                                     });
                                 }
@@ -596,7 +598,7 @@ where
                                 }
                             }
 
-                            let bounds = ty_to_bounds.entry(*ty.clone()).or_default();
+                            let bounds = ty_to_bounds.entry(ty.clone()).or_default();
 
                             bounds.insert(GenericBound::TraitBound(
                                 PolyTrait { trait_: new_trait, generic_params: Vec::new() },
@@ -613,7 +615,7 @@ where
                             ));
                             // Avoid creating any new duplicate bounds later in the outer
                             // loop
-                            ty_to_traits.entry(*ty.clone()).or_default().insert(trait_.clone());
+                            ty_to_traits.entry(ty.clone()).or_default().insert(trait_.clone());
                         }
                         _ => panic!("Unexpected LHS {:?} for {:?}", lhs, item_def_id),
                     }
diff --git a/src/librustdoc/clean/inline.rs b/src/librustdoc/clean/inline.rs
index e56a715e85780..a7048e788b65a 100644
--- a/src/librustdoc/clean/inline.rs
+++ b/src/librustdoc/clean/inline.rs
@@ -62,7 +62,7 @@ pub(crate) fn try_inline(
         Res::Def(DefKind::Trait, did) => {
             record_extern_fqn(cx, did, ItemType::Trait);
             build_impls(cx, Some(parent_module), did, attrs, &mut ret);
-            clean::TraitItem(build_external_trait(cx, did))
+            clean::TraitItem(Box::new(build_external_trait(cx, did)))
         }
         Res::Def(DefKind::Fn, did) => {
             record_extern_fqn(cx, did, ItemType::Function);
@@ -672,7 +672,7 @@ fn filter_non_trait_generics(trait_did: DefId, mut g: clean::Generics) -> clean:
 
     g.where_predicates.retain(|pred| match pred {
         clean::WherePredicate::BoundPredicate {
-            ty: clean::QPath { self_type: box clean::Generic(ref s), trait_, .. },
+            ty: clean::QPath(box clean::QPathData { self_type: clean::Generic(ref s), trait_, .. }),
             bounds,
             ..
         } => !(bounds.is_empty() || *s == kw::SelfUpper && trait_.def_id() == trait_did),
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index 971617a840036..5507ffb871b6e 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -410,12 +410,12 @@ fn clean_projection<'tcx>(
         self_type.def_id(&cx.cache)
     };
     let should_show_cast = compute_should_show_cast(self_def_id, &trait_, &self_type);
-    Type::QPath {
-        assoc: Box::new(projection_to_path_segment(ty, cx)),
+    Type::QPath(Box::new(QPathData {
+        assoc: projection_to_path_segment(ty, cx),
         should_show_cast,
-        self_type: Box::new(self_type),
+        self_type,
         trait_,
-    }
+    }))
 }
 
 fn compute_should_show_cast(self_def_id: Option<DefId>, trait_: &Path, self_type: &Type) -> bool {
@@ -1182,7 +1182,7 @@ pub(crate) fn clean_middle_assoc_item<'tcx>(
                     .where_predicates
                     .drain_filter(|pred| match *pred {
                         WherePredicate::BoundPredicate {
-                            ty: QPath { ref assoc, ref self_type, ref trait_, .. },
+                            ty: QPath(box QPathData { ref assoc, ref self_type, ref trait_, .. }),
                             ..
                         } => {
                             if assoc.name != my_name {
@@ -1191,7 +1191,7 @@ pub(crate) fn clean_middle_assoc_item<'tcx>(
                             if trait_.def_id() != assoc_item.container_id(tcx) {
                                 return false;
                             }
-                            match **self_type {
+                            match *self_type {
                                 Generic(ref s) if *s == kw::SelfUpper => {}
                                 _ => return false,
                             }
@@ -1324,15 +1324,12 @@ fn clean_qpath<'tcx>(hir_ty: &hir::Ty<'tcx>, cx: &mut DocContext<'tcx>) -> Type
             let self_def_id = DefId::local(qself.hir_id.owner.local_def_index);
             let self_type = clean_ty(qself, cx);
             let should_show_cast = compute_should_show_cast(Some(self_def_id), &trait_, &self_type);
-            Type::QPath {
-                assoc: Box::new(clean_path_segment(
-                    p.segments.last().expect("segments were empty"),
-                    cx,
-                )),
+            Type::QPath(Box::new(QPathData {
+                assoc: clean_path_segment(p.segments.last().expect("segments were empty"), cx),
                 should_show_cast,
-                self_type: Box::new(self_type),
+                self_type,
                 trait_,
-            }
+            }))
         }
         hir::QPath::TypeRelative(qself, segment) => {
             let ty = hir_ty_to_ty(cx.tcx, hir_ty);
@@ -1347,12 +1344,12 @@ fn clean_qpath<'tcx>(hir_ty: &hir::Ty<'tcx>, cx: &mut DocContext<'tcx>) -> Type
             let self_def_id = res.opt_def_id();
             let self_type = clean_ty(qself, cx);
             let should_show_cast = compute_should_show_cast(self_def_id, &trait_, &self_type);
-            Type::QPath {
-                assoc: Box::new(clean_path_segment(segment, cx)),
+            Type::QPath(Box::new(QPathData {
+                assoc: clean_path_segment(segment, cx),
                 should_show_cast,
-                self_type: Box::new(self_type),
+                self_type,
                 trait_,
-            }
+            }))
         }
         hir::QPath::LangItem(..) => bug!("clean: requiring documentation of lang item"),
     }
@@ -1954,12 +1951,12 @@ fn clean_maybe_renamed_item<'tcx>(
                     .map(|ti| clean_trait_item(cx.tcx.hir().trait_item(ti.id), cx))
                     .collect();
 
-                TraitItem(Trait {
+                TraitItem(Box::new(Trait {
                     def_id,
                     items,
                     generics: clean_generics(generics, cx),
                     bounds: bounds.iter().filter_map(|x| clean_generic_bound(x, cx)).collect(),
-                })
+                }))
             }
             ItemKind::ExternCrate(orig_name) => {
                 return clean_extern_crate(item, name, orig_name, cx);
diff --git a/src/librustdoc/clean/types.rs b/src/librustdoc/clean/types.rs
index 2a38713d43b8a..4c39021903c5b 100644
--- a/src/librustdoc/clean/types.rs
+++ b/src/librustdoc/clean/types.rs
@@ -727,7 +727,7 @@ pub(crate) enum ItemKind {
     OpaqueTyItem(OpaqueTy),
     StaticItem(Static),
     ConstantItem(Constant),
-    TraitItem(Trait),
+    TraitItem(Box<Trait>),
     TraitAliasItem(TraitAlias),
     ImplItem(Box<Impl>),
     /// A required method in a trait declaration meaning it's only a function signature.
@@ -1130,7 +1130,7 @@ pub struct RenderedLink {
 #[derive(Clone, Debug, Default)]
 pub(crate) struct Attributes {
     pub(crate) doc_strings: Vec<DocFragment>,
-    pub(crate) other_attrs: Vec<ast::Attribute>,
+    pub(crate) other_attrs: ast::AttrVec,
 }
 
 impl Attributes {
@@ -1173,7 +1173,7 @@ impl Attributes {
         doc_only: bool,
     ) -> Attributes {
         let mut doc_strings = Vec::new();
-        let mut other_attrs = Vec::new();
+        let mut other_attrs = ast::AttrVec::new();
         for (attr, parent_module) in attrs {
             if let Some((doc_str, comment_kind)) = attr.doc_str_and_comment_kind() {
                 trace!("got doc_str={doc_str:?}");
@@ -1550,13 +1550,7 @@ pub(crate) enum Type {
     BorrowedRef { lifetime: Option<Lifetime>, mutability: Mutability, type_: Box<Type> },
 
     /// A qualified path to an associated item: `<Type as Trait>::Name`
-    QPath {
-        assoc: Box<PathSegment>,
-        self_type: Box<Type>,
-        /// FIXME: compute this field on demand.
-        should_show_cast: bool,
-        trait_: Path,
-    },
+    QPath(Box<QPathData>),
 
     /// A type that is inferred: `_`
     Infer,
@@ -1654,8 +1648,8 @@ impl Type {
     }
 
     pub(crate) fn projection(&self) -> Option<(&Type, DefId, PathSegment)> {
-        if let QPath { self_type, trait_, assoc, .. } = self {
-            Some((self_type, trait_.def_id(), *assoc.clone()))
+        if let QPath(box QPathData { self_type, trait_, assoc, .. }) = self {
+            Some((self_type, trait_.def_id(), assoc.clone()))
         } else {
             None
         }
@@ -1679,7 +1673,7 @@ impl Type {
             Slice(..) => PrimitiveType::Slice,
             Array(..) => PrimitiveType::Array,
             RawPointer(..) => PrimitiveType::RawPointer,
-            QPath { ref self_type, .. } => return self_type.inner_def_id(cache),
+            QPath(box QPathData { ref self_type, .. }) => return self_type.inner_def_id(cache),
             Generic(_) | Infer | ImplTrait(_) => return None,
         };
         cache.and_then(|c| Primitive(t).def_id(c))
@@ -1693,6 +1687,15 @@ impl Type {
     }
 }
 
+#[derive(Clone, PartialEq, Eq, Debug, Hash)]
+pub(crate) struct QPathData {
+    pub assoc: PathSegment,
+    pub self_type: Type,
+    /// FIXME: compute this field on demand.
+    pub should_show_cast: bool,
+    pub trait_: Path,
+}
+
 /// A primitive (aka, builtin) type.
 ///
 /// This represents things like `i32`, `str`, etc.
@@ -2484,11 +2487,11 @@ mod size_asserts {
     // These are in alphabetical order, which is easy to maintain.
     static_assert_size!(Crate, 72); // frequently moved by-value
     static_assert_size!(DocFragment, 32);
-    static_assert_size!(GenericArg, 80);
+    static_assert_size!(GenericArg, 64);
     static_assert_size!(GenericArgs, 32);
     static_assert_size!(GenericParamDef, 56);
     static_assert_size!(Item, 56);
-    static_assert_size!(ItemKind, 112);
+    static_assert_size!(ItemKind, 96);
     static_assert_size!(PathSegment, 40);
-    static_assert_size!(Type, 72);
+    static_assert_size!(Type, 56);
 }
diff --git a/src/librustdoc/formats/cache.rs b/src/librustdoc/formats/cache.rs
index 2b2691e53bbcc..86392610d2c28 100644
--- a/src/librustdoc/formats/cache.rs
+++ b/src/librustdoc/formats/cache.rs
@@ -227,7 +227,7 @@ impl<'a, 'tcx> DocFolder for CacheBuilder<'a, 'tcx> {
         if let clean::TraitItem(ref t) = *item.kind {
             self.cache.traits.entry(item.item_id.expect_def_id()).or_insert_with(|| {
                 clean::TraitWithExtraInfo {
-                    trait_: t.clone(),
+                    trait_: *t.clone(),
                     is_notable: item.attrs.has_doc_flag(sym::notable_trait),
                 }
             });
diff --git a/src/librustdoc/html/format.rs b/src/librustdoc/html/format.rs
index 3dee4d1acc819..b023792e95a58 100644
--- a/src/librustdoc/html/format.rs
+++ b/src/librustdoc/html/format.rs
@@ -1079,7 +1079,12 @@ fn fmt_type<'cx>(
                 write!(f, "impl {}", print_generic_bounds(bounds, cx))
             }
         }
-        clean::QPath { ref assoc, ref self_type, ref trait_, should_show_cast } => {
+        clean::QPath(box clean::QPathData {
+            ref assoc,
+            ref self_type,
+            ref trait_,
+            should_show_cast,
+        }) => {
             if f.alternate() {
                 if should_show_cast {
                     write!(f, "<{:#} as {:#}>::", self_type.print(cx), trait_.print(cx))?
diff --git a/src/librustdoc/html/highlight.rs b/src/librustdoc/html/highlight.rs
index 9d8ee52a3faf8..4a12d74ddef5a 100644
--- a/src/librustdoc/html/highlight.rs
+++ b/src/librustdoc/html/highlight.rs
@@ -111,53 +111,6 @@ fn write_header(out: &mut Buffer, class: &str, extra_content: Option<Buffer>) {
     write!(out, "<code>");
 }
 
-/// Write all the pending elements sharing a same (or at mergeable) `Class`.
-///
-/// If there is a "parent" (if a `EnterSpan` event was encountered) and the parent can be merged
-/// with the elements' class, then we simply write the elements since the `ExitSpan` event will
-/// close the tag.
-///
-/// Otherwise, if there is only one pending element, we let the `string` function handle both
-/// opening and closing the tag, otherwise we do it into this function.
-fn write_pending_elems(
-    out: &mut Buffer,
-    href_context: &Option<HrefContext<'_, '_, '_>>,
-    pending_elems: &mut Vec<(&str, Option<Class>)>,
-    current_class: &mut Option<Class>,
-    closing_tags: &[(&str, Class)],
-) {
-    if pending_elems.is_empty() {
-        return;
-    }
-    let mut done = false;
-    if let Some((_, parent_class)) = closing_tags.last() {
-        if can_merge(*current_class, Some(*parent_class), "") {
-            for (text, class) in pending_elems.iter() {
-                string(out, Escape(text), *class, &href_context, false);
-            }
-            done = true;
-        }
-    }
-    if !done {
-        // We only want to "open" the tag ourselves if we have more than one pending and if the current
-        // parent tag is not the same as our pending content.
-        let open_tag_ourselves = pending_elems.len() > 1;
-        let close_tag = if open_tag_ourselves {
-            enter_span(out, current_class.unwrap(), &href_context)
-        } else {
-            ""
-        };
-        for (text, class) in pending_elems.iter() {
-            string(out, Escape(text), *class, &href_context, !open_tag_ourselves);
-        }
-        if open_tag_ourselves {
-            exit_span(out, close_tag);
-        }
-    }
-    pending_elems.clear();
-    *current_class = None;
-}
-
 /// Check if two `Class` can be merged together. In the following rules, "unclassified" means `None`
 /// basically (since it's `Option<Class>`). The following rules apply:
 ///
@@ -171,7 +124,88 @@ fn can_merge(class1: Option<Class>, class2: Option<Class>, text: &str) -> bool {
         (Some(c1), Some(c2)) => c1.is_equal_to(c2),
         (Some(Class::Ident(_)), None) | (None, Some(Class::Ident(_))) => true,
         (Some(_), None) | (None, Some(_)) => text.trim().is_empty(),
-        _ => false,
+        (None, None) => true,
+    }
+}
+
+/// This type is used as a conveniency to prevent having to pass all its fields as arguments into
+/// the various functions (which became its methods).
+struct TokenHandler<'a, 'b, 'c, 'd, 'e> {
+    out: &'a mut Buffer,
+    /// It contains the closing tag and the associated `Class`.
+    closing_tags: Vec<(&'static str, Class)>,
+    /// This is used because we don't automatically generate the closing tag on `ExitSpan` in
+    /// case an `EnterSpan` event with the same class follows.
+    pending_exit_span: Option<Class>,
+    /// `current_class` and `pending_elems` are used to group HTML elements with same `class`
+    /// attributes to reduce the DOM size.
+    current_class: Option<Class>,
+    /// We need to keep the `Class` for each element because it could contain a `Span` which is
+    /// used to generate links.
+    pending_elems: Vec<(&'b str, Option<Class>)>,
+    href_context: Option<HrefContext<'c, 'd, 'e>>,
+}
+
+impl<'a, 'b, 'c, 'd, 'e> TokenHandler<'a, 'b, 'c, 'd, 'e> {
+    fn handle_exit_span(&mut self) {
+        // We can't get the last `closing_tags` element using `pop()` because `closing_tags` is
+        // being used in `write_pending_elems`.
+        let class = self.closing_tags.last().expect("ExitSpan without EnterSpan").1;
+        // We flush everything just in case...
+        self.write_pending_elems(Some(class));
+
+        exit_span(self.out, self.closing_tags.pop().expect("ExitSpan without EnterSpan").0);
+        self.pending_exit_span = None;
+    }
+
+    /// Write all the pending elements sharing a same (or at mergeable) `Class`.
+    ///
+    /// If there is a "parent" (if a `EnterSpan` event was encountered) and the parent can be merged
+    /// with the elements' class, then we simply write the elements since the `ExitSpan` event will
+    /// close the tag.
+    ///
+    /// Otherwise, if there is only one pending element, we let the `string` function handle both
+    /// opening and closing the tag, otherwise we do it into this function.
+    ///
+    /// It returns `true` if `current_class` must be set to `None` afterwards.
+    fn write_pending_elems(&mut self, current_class: Option<Class>) -> bool {
+        if self.pending_elems.is_empty() {
+            return false;
+        }
+        if let Some((_, parent_class)) = self.closing_tags.last() &&
+            can_merge(current_class, Some(*parent_class), "")
+        {
+            for (text, class) in self.pending_elems.iter() {
+                string(self.out, Escape(text), *class, &self.href_context, false);
+            }
+        } else {
+            // We only want to "open" the tag ourselves if we have more than one pending and if the
+            // current parent tag is not the same as our pending content.
+            let close_tag = if self.pending_elems.len() > 1 && current_class.is_some() {
+                Some(enter_span(self.out, current_class.unwrap(), &self.href_context))
+            } else {
+                None
+            };
+            for (text, class) in self.pending_elems.iter() {
+                string(self.out, Escape(text), *class, &self.href_context, close_tag.is_none());
+            }
+            if let Some(close_tag) = close_tag {
+                exit_span(self.out, close_tag);
+            }
+        }
+        self.pending_elems.clear();
+        true
+    }
+}
+
+impl<'a, 'b, 'c, 'd, 'e> Drop for TokenHandler<'a, 'b, 'c, 'd, 'e> {
+    /// When leaving, we need to flush all pending data to not have missing content.
+    fn drop(&mut self) {
+        if self.pending_exit_span.is_some() {
+            self.handle_exit_span();
+        } else {
+            self.write_pending_elems(self.current_class);
+        }
     }
 }
 
@@ -194,64 +228,72 @@ fn write_code(
 ) {
     // This replace allows to fix how the code source with DOS backline characters is displayed.
     let src = src.replace("\r\n", "\n");
-    // It contains the closing tag and the associated `Class`.
-    let mut closing_tags: Vec<(&'static str, Class)> = Vec::new();
-    // The following two variables are used to group HTML elements with same `class` attributes
-    // to reduce the DOM size.
-    let mut current_class: Option<Class> = None;
-    // We need to keep the `Class` for each element because it could contain a `Span` which is
-    // used to generate links.
-    let mut pending_elems: Vec<(&str, Option<Class>)> = Vec::new();
+    let mut token_handler = TokenHandler {
+        out,
+        closing_tags: Vec::new(),
+        pending_exit_span: None,
+        current_class: None,
+        pending_elems: Vec::new(),
+        href_context,
+    };
 
     Classifier::new(
         &src,
-        href_context.as_ref().map(|c| c.file_span).unwrap_or(DUMMY_SP),
+        token_handler.href_context.as_ref().map(|c| c.file_span).unwrap_or(DUMMY_SP),
         decoration_info,
     )
     .highlight(&mut |highlight| {
         match highlight {
             Highlight::Token { text, class } => {
+                // If we received a `ExitSpan` event and then have a non-compatible `Class`, we
+                // need to close the `<span>`.
+                let need_current_class_update = if let Some(pending) = token_handler.pending_exit_span &&
+                    !can_merge(Some(pending), class, text) {
+                        token_handler.handle_exit_span();
+                        true
                 // If the two `Class` are different, time to flush the current content and start
                 // a new one.
-                if !can_merge(current_class, class, text) {
-                    write_pending_elems(
-                        out,
-                        &href_context,
-                        &mut pending_elems,
-                        &mut current_class,
-                        &closing_tags,
-                    );
-                    current_class = class.map(Class::dummy);
-                } else if current_class.is_none() {
-                    current_class = class.map(Class::dummy);
+                } else if !can_merge(token_handler.current_class, class, text) {
+                    token_handler.write_pending_elems(token_handler.current_class);
+                    true
+                } else {
+                    token_handler.current_class.is_none()
+                };
+
+                if need_current_class_update {
+                    token_handler.current_class = class.map(Class::dummy);
                 }
-                pending_elems.push((text, class));
+                token_handler.pending_elems.push((text, class));
             }
             Highlight::EnterSpan { class } => {
-                // We flush everything just in case...
-                write_pending_elems(
-                    out,
-                    &href_context,
-                    &mut pending_elems,
-                    &mut current_class,
-                    &closing_tags,
-                );
-                closing_tags.push((enter_span(out, class, &href_context), class))
+                let mut should_add = true;
+                if let Some(pending_exit_span) = token_handler.pending_exit_span {
+                    if class.is_equal_to(pending_exit_span) {
+                        should_add = false;
+                    } else {
+                        token_handler.handle_exit_span();
+                    }
+                } else {
+                    // We flush everything just in case...
+                    if token_handler.write_pending_elems(token_handler.current_class) {
+                        token_handler.current_class = None;
+                    }
+                }
+                if should_add {
+                    let closing_tag = enter_span(token_handler.out, class, &token_handler.href_context);
+                    token_handler.closing_tags.push((closing_tag, class));
+                }
+
+                token_handler.current_class = None;
+                token_handler.pending_exit_span = None;
             }
             Highlight::ExitSpan => {
-                // We flush everything just in case...
-                write_pending_elems(
-                    out,
-                    &href_context,
-                    &mut pending_elems,
-                    &mut current_class,
-                    &closing_tags,
-                );
-                exit_span(out, closing_tags.pop().expect("ExitSpan without EnterSpan").0)
+                token_handler.current_class = None;
+                token_handler.pending_exit_span =
+                    Some(token_handler.closing_tags.last().as_ref().expect("ExitSpan without EnterSpan").1);
             }
         };
     });
-    write_pending_elems(out, &href_context, &mut pending_elems, &mut current_class, &closing_tags);
 }
 
 fn write_footer(out: &mut Buffer, playground_button: Option<&str>) {
@@ -291,8 +333,8 @@ impl Class {
         match (self, other) {
             (Self::Self_(_), Self::Self_(_))
             | (Self::Macro(_), Self::Macro(_))
-            | (Self::Ident(_), Self::Ident(_))
-            | (Self::Decoration(_), Self::Decoration(_)) => true,
+            | (Self::Ident(_), Self::Ident(_)) => true,
+            (Self::Decoration(c1), Self::Decoration(c2)) => c1 == c2,
             (x, y) => x == y,
         }
     }
@@ -761,7 +803,7 @@ impl<'a> Classifier<'a> {
             TokenKind::CloseBracket => {
                 if self.in_attribute {
                     self.in_attribute = false;
-                    sink(Highlight::Token { text: "]", class: Some(Class::Attribute) });
+                    sink(Highlight::Token { text: "]", class: None });
                     sink(Highlight::ExitSpan);
                     return;
                 }
diff --git a/src/librustdoc/html/highlight/fixtures/decorations.html b/src/librustdoc/html/highlight/fixtures/decorations.html
index 2184897872153..ebf29f9cb3a91 100644
--- a/src/librustdoc/html/highlight/fixtures/decorations.html
+++ b/src/librustdoc/html/highlight/fixtures/decorations.html
@@ -1,2 +1,4 @@
-<span class="example"><span class="kw">let </span>x = <span class="number">1</span>;</span>
-<span class="kw">let </span>y = <span class="number">2</span>;
\ No newline at end of file
+<span class="example"><span class="kw">let </span>x = <span class="number">1</span>;
+<span class="kw">let </span>y = <span class="number">2</span>;
+</span><span class="example2"><span class="kw">let </span>z = <span class="number">3</span>;
+</span><span class="kw">let </span>a = <span class="number">4</span>;
\ No newline at end of file
diff --git a/src/librustdoc/html/highlight/fixtures/sample.html b/src/librustdoc/html/highlight/fixtures/sample.html
index ae2650528eb72..4a5a3cf609cd4 100644
--- a/src/librustdoc/html/highlight/fixtures/sample.html
+++ b/src/librustdoc/html/highlight/fixtures/sample.html
@@ -8,12 +8,13 @@
 .lifetime { color: #B76514; }
 .question-mark { color: #ff9011; }
 </style>
-<pre><code><span class="attribute">#![crate_type = <span class="string">&quot;lib&quot;</span>]</span>
+<pre><code><span class="attribute">#![crate_type = <span class="string">&quot;lib&quot;</span>]
 
-<span class="kw">use </span>std::path::{Path, PathBuf};
+</span><span class="kw">use </span>std::path::{Path, PathBuf};
 
-<span class="attribute">#[cfg(target_os = <span class="string">&quot;linux&quot;</span>)]</span>
-<span class="kw">fn </span>main() -&gt; () {
+<span class="attribute">#[cfg(target_os = <span class="string">&quot;linux&quot;</span>)]
+#[cfg(target_os = <span class="string">&quot;windows&quot;</span>)]
+</span><span class="kw">fn </span>main() -&gt; () {
     <span class="kw">let </span>foo = <span class="bool-val">true </span>&amp;&amp; <span class="bool-val">false </span>|| <span class="bool-val">true</span>;
     <span class="kw">let _</span>: <span class="kw-2">*const </span>() = <span class="number">0</span>;
     <span class="kw">let _ </span>= <span class="kw-2">&amp;</span>foo;
@@ -22,8 +23,8 @@
     <span class="macro">mac!</span>(foo, <span class="kw-2">&amp;mut </span>bar);
     <span class="macro">assert!</span>(<span class="self">self</span>.length &lt; N &amp;&amp; index &lt;= <span class="self">self</span>.length);
     ::std::env::var(<span class="string">&quot;gateau&quot;</span>).is_ok();
-    <span class="attribute">#[rustfmt::skip]</span>
-    <span class="kw">let </span>s:std::path::PathBuf = std::path::PathBuf::new();
+    <span class="attribute">#[rustfmt::skip]
+    </span><span class="kw">let </span>s:std::path::PathBuf = std::path::PathBuf::new();
     <span class="kw">let </span><span class="kw-2">mut </span>s = String::new();
 
     <span class="kw">match </span><span class="kw-2">&amp;</span>s {
@@ -31,7 +32,7 @@
     }
 }
 
-<span class="macro">macro_rules!</span> bar {
+<span class="macro">macro_rules! </span>bar {
     (<span class="macro-nonterminal">$foo</span>:tt) =&gt; {};
 }
 </code></pre>
diff --git a/src/librustdoc/html/highlight/fixtures/sample.rs b/src/librustdoc/html/highlight/fixtures/sample.rs
index fbfdc6767337c..ef85b566cb3c4 100644
--- a/src/librustdoc/html/highlight/fixtures/sample.rs
+++ b/src/librustdoc/html/highlight/fixtures/sample.rs
@@ -3,6 +3,7 @@
 use std::path::{Path, PathBuf};
 
 #[cfg(target_os = "linux")]
+#[cfg(target_os = "windows")]
 fn main() -> () {
     let foo = true && false || true;
     let _: *const () = 0;
diff --git a/src/librustdoc/html/highlight/tests.rs b/src/librustdoc/html/highlight/tests.rs
index 4861a8ad32da6..a5e633df43448 100644
--- a/src/librustdoc/html/highlight/tests.rs
+++ b/src/librustdoc/html/highlight/tests.rs
@@ -69,9 +69,12 @@ fn test_union_highlighting() {
 fn test_decorations() {
     create_default_session_globals_then(|| {
         let src = "let x = 1;
-let y = 2;";
+let y = 2;
+let z = 3;
+let a = 4;";
         let mut decorations = FxHashMap::default();
-        decorations.insert("example", vec![(0, 10)]);
+        decorations.insert("example", vec![(0, 10), (11, 21)]);
+        decorations.insert("example2", vec![(22, 32)]);
 
         let mut html = Buffer::new();
         write_code(&mut html, src, None, Some(DecorationInfo(decorations)));
diff --git a/src/librustdoc/html/render/mod.rs b/src/librustdoc/html/render/mod.rs
index 2b66ab22475d4..f9d6b4619cc77 100644
--- a/src/librustdoc/html/render/mod.rs
+++ b/src/librustdoc/html/render/mod.rs
@@ -2632,8 +2632,8 @@ fn collect_paths_for_type(first_ty: clean::Type, cache: &Cache) -> Vec<String> {
             clean::Type::BorrowedRef { type_, .. } => {
                 work.push_back(*type_);
             }
-            clean::Type::QPath { self_type, trait_, .. } => {
-                work.push_back(*self_type);
+            clean::Type::QPath(box clean::QPathData { self_type, trait_, .. }) => {
+                work.push_back(self_type);
                 process_path(trait_.def_id());
             }
             _ => {}
diff --git a/src/librustdoc/json/conversions.rs b/src/librustdoc/json/conversions.rs
index 1fedb0144d1d0..c4e8b6f5f8449 100644
--- a/src/librustdoc/json/conversions.rs
+++ b/src/librustdoc/json/conversions.rs
@@ -248,7 +248,7 @@ fn from_clean_item(item: clean::Item, tcx: TyCtxt<'_>) -> ItemEnum {
         VariantItem(v) => ItemEnum::Variant(v.into_tcx(tcx)),
         FunctionItem(f) => ItemEnum::Function(from_function(f, header.unwrap(), tcx)),
         ForeignFunctionItem(f) => ItemEnum::Function(from_function(f, header.unwrap(), tcx)),
-        TraitItem(t) => ItemEnum::Trait(t.into_tcx(tcx)),
+        TraitItem(t) => ItemEnum::Trait((*t).into_tcx(tcx)),
         TraitAliasItem(t) => ItemEnum::TraitAlias(t.into_tcx(tcx)),
         MethodItem(m, _) => ItemEnum::Method(from_function_method(m, true, header.unwrap(), tcx)),
         TyMethodItem(m) => ItemEnum::Method(from_function_method(m, false, header.unwrap(), tcx)),
@@ -480,10 +480,10 @@ impl FromWithTcx<clean::Type> for Type {
                 mutable: mutability == ast::Mutability::Mut,
                 type_: Box::new((*type_).into_tcx(tcx)),
             },
-            QPath { assoc, self_type, trait_, .. } => Type::QualifiedPath {
+            QPath(box clean::QPathData { assoc, self_type, trait_, .. }) => Type::QualifiedPath {
                 name: assoc.name.to_string(),
                 args: Box::new(assoc.args.clone().into_tcx(tcx)),
-                self_type: Box::new((*self_type).into_tcx(tcx)),
+                self_type: Box::new(self_type.into_tcx(tcx)),
                 trait_: trait_.into_tcx(tcx),
             },
         }
diff --git a/src/test/assembly/x86_64-floating-point-clamp.rs b/src/test/assembly/x86_64-floating-point-clamp.rs
new file mode 100644
index 0000000000000..0f3b465d08d4f
--- /dev/null
+++ b/src/test/assembly/x86_64-floating-point-clamp.rs
@@ -0,0 +1,25 @@
+// Floating-point clamp is designed to be implementable as max+min,
+// so check to make sure that's what it's actually emitting.
+
+// assembly-output: emit-asm
+// compile-flags: --crate-type=lib -O -C llvm-args=-x86-asm-syntax=intel
+// only-x86_64
+
+// CHECK-LABEL: clamp_demo:
+#[no_mangle]
+pub fn clamp_demo(a: f32, x: f32, y: f32) -> f32 {
+    // CHECK: maxss
+    // CHECK: minss
+    a.clamp(x, y)
+}
+
+// CHECK-LABEL: clamp12_demo:
+#[no_mangle]
+pub fn clamp12_demo(a: f32) -> f32 {
+    // CHECK: movss   xmm1
+    // CHECK-NEXT: maxss   xmm1, xmm0
+    // CHECK-NEXT: movss   xmm0
+    // CHECK-NEXT: minss   xmm0, xmm1
+    // CHECK: ret
+    a.clamp(1.0, 2.0)
+}
diff --git a/src/test/codegen/pic-relocation-model.rs b/src/test/codegen/pic-relocation-model.rs
index 6e1d5a6c3f271..bcfe2f9af50bd 100644
--- a/src/test/codegen/pic-relocation-model.rs
+++ b/src/test/codegen/pic-relocation-model.rs
@@ -13,4 +13,4 @@ pub fn call_foreign_fn() -> u8 {
 // CHECK: declare zeroext i8 @foreign_fn()
 extern "C" {fn foreign_fn() -> u8;}
 
-// CHECK: !{i32 7, !"PIC Level", i32 2}
+// CHECK: !{i32 {{[78]}}, !"PIC Level", i32 2}
diff --git a/src/test/codegen/pie-relocation-model.rs b/src/test/codegen/pie-relocation-model.rs
index a843202a94f82..ec44edc066774 100644
--- a/src/test/codegen/pie-relocation-model.rs
+++ b/src/test/codegen/pie-relocation-model.rs
@@ -18,5 +18,5 @@ pub fn call_foreign_fn() -> u8 {
 // CHECK: declare zeroext i8 @foreign_fn()
 extern "C" {fn foreign_fn() -> u8;}
 
-// CHECK: !{i32 7, !"PIC Level", i32 2}
+// CHECK: !{i32 {{[78]}}, !"PIC Level", i32 2}
 // CHECK: !{i32 7, !"PIE Level", i32 2}
diff --git a/src/test/rustdoc/issue-41783.codeblock.html b/src/test/rustdoc/issue-41783.codeblock.html
index b919935e4b47a..89987491d1b46 100644
--- a/src/test/rustdoc/issue-41783.codeblock.html
+++ b/src/test/rustdoc/issue-41783.codeblock.html
@@ -1,5 +1,5 @@
 <code># single
 ## double
 ### triple
-<span class="attribute">#[outer]</span>
-<span class="attribute">#![inner]</span></code>
\ No newline at end of file
+<span class="attribute">#[outer]
+#![inner]</span></code>
diff --git a/src/test/rustdoc/issue-41783.rs b/src/test/rustdoc/issue-41783.rs
index d67716028799b..87267a750c615 100644
--- a/src/test/rustdoc/issue-41783.rs
+++ b/src/test/rustdoc/issue-41783.rs
@@ -1,8 +1,10 @@
 // @has issue_41783/struct.Foo.html
 // @!hasraw - 'space'
 // @!hasraw - 'comment'
-// @hasraw - '<span class="attribute">#[outer]</span>'
-// @hasraw - '<span class="attribute">#![inner]</span>'
+// @hasraw - '<span class="attribute">#[outer]'
+// @!hasraw - '<span class="attribute">#[outer]</span>'
+// @hasraw - '#![inner]</span>'
+// @!hasraw - '<span class="attribute">#![inner]</span>'
 // @snapshot 'codeblock' - '//*[@class="rustdoc-toggle top-doc"]/*[@class="docblock"]//pre/code'
 
 /// ```no_run
diff --git a/src/test/ui-fulldeps/internal-lints/diagnostics.rs b/src/test/ui-fulldeps/internal-lints/diagnostics.rs
index d6f63d44ba6a8..33192433bbf38 100644
--- a/src/test/ui-fulldeps/internal-lints/diagnostics.rs
+++ b/src/test/ui-fulldeps/internal-lints/diagnostics.rs
@@ -16,7 +16,7 @@ use rustc_session::{parse::ParseSess, SessionDiagnostic};
 use rustc_span::Span;
 
 #[derive(SessionDiagnostic)]
-#[error(parser::expect_path)]
+#[diag(parser::expect_path)]
 struct DeriveSessionDiagnostic {
     #[primary_span]
     span: Span,
diff --git a/src/test/ui-fulldeps/pprust-expr-roundtrip.rs b/src/test/ui-fulldeps/pprust-expr-roundtrip.rs
index 0d9c9350efca4..117b798710cf0 100644
--- a/src/test/ui-fulldeps/pprust-expr-roundtrip.rs
+++ b/src/test/ui-fulldeps/pprust-expr-roundtrip.rs
@@ -30,7 +30,6 @@ use rustc_ast::mut_visit::{self, visit_clobber, MutVisitor};
 use rustc_ast::ptr::P;
 use rustc_ast::*;
 use rustc_ast_pretty::pprust;
-use rustc_data_structures::thin_vec::ThinVec;
 use rustc_parse::new_parser_from_source_str;
 use rustc_session::parse::ParseSess;
 use rustc_span::source_map::FilePathMapping;
@@ -47,7 +46,7 @@ fn parse_expr(ps: &ParseSess, src: &str) -> Option<P<Expr>> {
 
 // Helper functions for building exprs
 fn expr(kind: ExprKind) -> P<Expr> {
-    P(Expr { id: DUMMY_NODE_ID, kind, span: DUMMY_SP, attrs: ThinVec::new(), tokens: None })
+    P(Expr { id: DUMMY_NODE_ID, kind, span: DUMMY_SP, attrs: AttrVec::new(), tokens: None })
 }
 
 fn make_x() -> P<Expr> {
@@ -196,7 +195,7 @@ impl MutVisitor for AddParens {
                 id: DUMMY_NODE_ID,
                 kind: ExprKind::Paren(e),
                 span: DUMMY_SP,
-                attrs: ThinVec::new(),
+                attrs: AttrVec::new(),
                 tokens: None,
             })
         });
diff --git a/src/test/ui-fulldeps/session-diagnostic/diagnostic-derive.rs b/src/test/ui-fulldeps/session-diagnostic/diagnostic-derive.rs
index 0a210cbdc9430..aaa8caa64f343 100644
--- a/src/test/ui-fulldeps/session-diagnostic/diagnostic-derive.rs
+++ b/src/test/ui-fulldeps/session-diagnostic/diagnostic-derive.rs
@@ -28,15 +28,15 @@ use rustc_errors::{Applicability, MultiSpan};
 extern crate rustc_session;
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct Hello {}
 
 #[derive(SessionDiagnostic)]
-#[warning(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct HelloWarn {}
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 //~^ ERROR `#[derive(SessionDiagnostic)]` can only be used on structs
 enum SessionDiagnosticOnEnum {
     Foo,
@@ -44,54 +44,54 @@ enum SessionDiagnosticOnEnum {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
-#[error = "E0123"]
-//~^ ERROR `#[error = ...]` is not a valid attribute
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag = "E0123"]
+//~^ ERROR `#[diag = ...]` is not a valid attribute
 struct WrongStructAttrStyle {}
 
 #[derive(SessionDiagnostic)]
 #[nonsense(typeck::ambiguous_lifetime_bound, code = "E0123")]
 //~^ ERROR `#[nonsense(...)]` is not a valid attribute
-//~^^ ERROR diagnostic kind not specified
+//~^^ ERROR diagnostic slug not specified
 //~^^^ ERROR cannot find attribute `nonsense` in this scope
 struct InvalidStructAttr {}
 
 #[derive(SessionDiagnostic)]
-#[error("E0123")]
-//~^ ERROR `#[error("...")]` is not a valid attribute
+#[diag("E0123")]
+//~^ ERROR `#[diag("...")]` is not a valid attribute
 //~^^ ERROR diagnostic slug not specified
 struct InvalidLitNestedAttr {}
 
 #[derive(SessionDiagnostic)]
-#[error(nonsense, code = "E0123")]
+#[diag(nonsense, code = "E0123")]
 //~^ ERROR cannot find value `nonsense` in module `rustc_errors::fluent`
 struct InvalidNestedStructAttr {}
 
 #[derive(SessionDiagnostic)]
-#[error(nonsense("foo"), code = "E0123", slug = "foo")]
-//~^ ERROR `#[error(nonsense(...))]` is not a valid attribute
+#[diag(nonsense("foo"), code = "E0123", slug = "foo")]
+//~^ ERROR `#[diag(nonsense(...))]` is not a valid attribute
 //~^^ ERROR diagnostic slug not specified
 struct InvalidNestedStructAttr1 {}
 
 #[derive(SessionDiagnostic)]
-#[error(nonsense = "...", code = "E0123", slug = "foo")]
-//~^ ERROR `#[error(nonsense = ...)]` is not a valid attribute
+#[diag(nonsense = "...", code = "E0123", slug = "foo")]
+//~^ ERROR `#[diag(nonsense = ...)]` is not a valid attribute
 //~^^ ERROR diagnostic slug not specified
 struct InvalidNestedStructAttr2 {}
 
 #[derive(SessionDiagnostic)]
-#[error(nonsense = 4, code = "E0123", slug = "foo")]
-//~^ ERROR `#[error(nonsense = ...)]` is not a valid attribute
+#[diag(nonsense = 4, code = "E0123", slug = "foo")]
+//~^ ERROR `#[diag(nonsense = ...)]` is not a valid attribute
 //~^^ ERROR diagnostic slug not specified
 struct InvalidNestedStructAttr3 {}
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123", slug = "foo")]
-//~^ ERROR `#[error(slug = ...)]` is not a valid attribute
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123", slug = "foo")]
+//~^ ERROR `#[diag(slug = ...)]` is not a valid attribute
 struct InvalidNestedStructAttr4 {}
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct WrongPlaceField {
     #[suggestion = "bar"]
     //~^ ERROR `#[suggestion = ...]` is not a valid attribute
@@ -99,45 +99,36 @@ struct WrongPlaceField {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0456")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0456")]
 //~^ ERROR specified multiple times
 //~^^ ERROR specified multiple times
-//~^^^ ERROR specified multiple times
-struct ErrorSpecifiedTwice {}
+struct DiagSpecifiedTwice {}
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
-#[warning(typeck::ambiguous_lifetime_bound, code = "E0293")]
-//~^ ERROR specified multiple times
-//~^^ ERROR specified multiple times
-//~^^^ ERROR specified multiple times
-struct WarnSpecifiedAfterError {}
-
-#[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0456", code = "E0457")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0456", code = "E0457")]
 //~^ ERROR specified multiple times
 struct CodeSpecifiedTwice {}
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, typeck::ambiguous_lifetime_bound, code = "E0456")]
-//~^ ERROR `#[error(typeck::ambiguous_lifetime_bound)]` is not a valid attribute
+#[diag(typeck::ambiguous_lifetime_bound, typeck::ambiguous_lifetime_bound, code = "E0456")]
+//~^ ERROR `#[diag(typeck::ambiguous_lifetime_bound)]` is not a valid attribute
 struct SlugSpecifiedTwice {}
 
 #[derive(SessionDiagnostic)]
-struct KindNotProvided {} //~ ERROR diagnostic kind not specified
+struct KindNotProvided {} //~ ERROR diagnostic slug not specified
 
 #[derive(SessionDiagnostic)]
-#[error(code = "E0456")]
+#[diag(code = "E0456")]
 //~^ ERROR diagnostic slug not specified
 struct SlugNotProvided {}
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound)]
+#[diag(typeck::ambiguous_lifetime_bound)]
 struct CodeNotProvided {}
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct MessageWrongType {
     #[primary_span]
     //~^ ERROR `#[primary_span]` attribute can only be applied to fields of type `Span` or `MultiSpan`
@@ -145,7 +136,7 @@ struct MessageWrongType {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct InvalidPathFieldAttr {
     #[nonsense]
     //~^ ERROR `#[nonsense]` is not a valid attribute
@@ -154,7 +145,7 @@ struct InvalidPathFieldAttr {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct ErrorWithField {
     name: String,
     #[label(typeck::label)]
@@ -162,7 +153,7 @@ struct ErrorWithField {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct ErrorWithMessageAppliedToField {
     #[label(typeck::label)]
     //~^ ERROR the `#[label(...)]` attribute can only be applied to fields of type `Span` or `MultiSpan`
@@ -170,7 +161,7 @@ struct ErrorWithMessageAppliedToField {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct ErrorWithNonexistentField {
     #[suggestion(typeck::suggestion, code = "{name}")]
     //~^ ERROR `name` doesn't refer to a field on this type
@@ -179,7 +170,7 @@ struct ErrorWithNonexistentField {
 
 #[derive(SessionDiagnostic)]
 //~^ ERROR invalid format string: expected `'}'`
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct ErrorMissingClosingBrace {
     #[suggestion(typeck::suggestion, code = "{name")]
     suggestion: (Span, Applicability),
@@ -189,7 +180,7 @@ struct ErrorMissingClosingBrace {
 
 #[derive(SessionDiagnostic)]
 //~^ ERROR invalid format string: unmatched `}`
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct ErrorMissingOpeningBrace {
     #[suggestion(typeck::suggestion, code = "name}")]
     suggestion: (Span, Applicability),
@@ -198,14 +189,14 @@ struct ErrorMissingOpeningBrace {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct LabelOnSpan {
     #[label(typeck::label)]
     sp: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct LabelOnNonSpan {
     #[label(typeck::label)]
     //~^ ERROR the `#[label(...)]` attribute can only be applied to fields of type `Span` or `MultiSpan`
@@ -213,7 +204,7 @@ struct LabelOnNonSpan {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct Suggest {
     #[suggestion(typeck::suggestion, code = "This is the suggested code")]
     #[suggestion_short(typeck::suggestion, code = "This is the suggested code")]
@@ -223,14 +214,14 @@ struct Suggest {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct SuggestWithoutCode {
     #[suggestion(typeck::suggestion)]
     suggestion: (Span, Applicability),
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct SuggestWithBadKey {
     #[suggestion(nonsense = "bar")]
     //~^ ERROR `#[suggestion(nonsense = ...)]` is not a valid attribute
@@ -238,7 +229,7 @@ struct SuggestWithBadKey {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct SuggestWithShorthandMsg {
     #[suggestion(msg = "bar")]
     //~^ ERROR `#[suggestion(msg = ...)]` is not a valid attribute
@@ -246,21 +237,21 @@ struct SuggestWithShorthandMsg {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct SuggestWithoutMsg {
     #[suggestion(code = "bar")]
     suggestion: (Span, Applicability),
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct SuggestWithTypesSwapped {
     #[suggestion(typeck::suggestion, code = "This is suggested code")]
     suggestion: (Applicability, Span),
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct SuggestWithWrongTypeApplicabilityOnly {
     #[suggestion(typeck::suggestion, code = "This is suggested code")]
     //~^ ERROR wrong field type for suggestion
@@ -268,14 +259,14 @@ struct SuggestWithWrongTypeApplicabilityOnly {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct SuggestWithSpanOnly {
     #[suggestion(typeck::suggestion, code = "This is suggested code")]
     suggestion: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct SuggestWithDuplicateSpanAndApplicability {
     #[suggestion(typeck::suggestion, code = "This is suggested code")]
     //~^ ERROR type of field annotated with `#[suggestion(...)]` contains more than one `Span`
@@ -283,7 +274,7 @@ struct SuggestWithDuplicateSpanAndApplicability {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct SuggestWithDuplicateApplicabilityAndSpan {
     #[suggestion(typeck::suggestion, code = "This is suggested code")]
     //~^ ERROR type of field annotated with `#[suggestion(...)]` contains more than one
@@ -291,7 +282,7 @@ struct SuggestWithDuplicateApplicabilityAndSpan {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct WrongKindOfAnnotation {
     #[label = "bar"]
     //~^ ERROR `#[label = ...]` is not a valid attribute
@@ -299,7 +290,7 @@ struct WrongKindOfAnnotation {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct OptionsInErrors {
     #[label(typeck::label)]
     label: Option<Span>,
@@ -308,7 +299,7 @@ struct OptionsInErrors {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0456")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0456")]
 struct MoveOutOfBorrowError<'tcx> {
     name: Ident,
     ty: Ty<'tcx>,
@@ -322,7 +313,7 @@ struct MoveOutOfBorrowError<'tcx> {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct ErrorWithLifetime<'a> {
     #[label(typeck::label)]
     span: Span,
@@ -330,7 +321,7 @@ struct ErrorWithLifetime<'a> {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct ErrorWithDefaultLabelAttr<'a> {
     #[label]
     span: Span,
@@ -339,7 +330,7 @@ struct ErrorWithDefaultLabelAttr<'a> {
 
 #[derive(SessionDiagnostic)]
 //~^ ERROR the trait bound `Hello: IntoDiagnosticArg` is not satisfied
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct ArgFieldWithoutSkip {
     #[primary_span]
     span: Span,
@@ -347,7 +338,7 @@ struct ArgFieldWithoutSkip {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct ArgFieldWithSkip {
     #[primary_span]
     span: Span,
@@ -358,56 +349,56 @@ struct ArgFieldWithSkip {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct ErrorWithSpannedNote {
     #[note]
     span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct ErrorWithSpannedNoteCustom {
     #[note(typeck::note)]
     span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 #[note]
 struct ErrorWithNote {
     val: String,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 #[note(typeck::note)]
 struct ErrorWithNoteCustom {
     val: String,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct ErrorWithSpannedHelp {
     #[help]
     span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct ErrorWithSpannedHelpCustom {
     #[help(typeck::help)]
     span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 #[help]
 struct ErrorWithHelp {
     val: String,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 #[help(typeck::help)]
 struct ErrorWithHelpCustom {
     val: String,
@@ -415,34 +406,34 @@ struct ErrorWithHelpCustom {
 
 #[derive(SessionDiagnostic)]
 #[help]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct ErrorWithHelpWrongOrder {
     val: String,
 }
 
 #[derive(SessionDiagnostic)]
 #[help(typeck::help)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct ErrorWithHelpCustomWrongOrder {
     val: String,
 }
 
 #[derive(SessionDiagnostic)]
 #[note]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct ErrorWithNoteWrongOrder {
     val: String,
 }
 
 #[derive(SessionDiagnostic)]
 #[note(typeck::note)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct ErrorWithNoteCustomWrongOrder {
     val: String,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct ApplicabilityInBoth {
     #[suggestion(typeck::suggestion, code = "...", applicability = "maybe-incorrect")]
     //~^ ERROR applicability cannot be set in both the field and attribute
@@ -450,7 +441,7 @@ struct ApplicabilityInBoth {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct InvalidApplicability {
     #[suggestion(typeck::suggestion, code = "...", applicability = "batman")]
     //~^ ERROR invalid applicability
@@ -458,14 +449,14 @@ struct InvalidApplicability {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct ValidApplicability {
     #[suggestion(typeck::suggestion, code = "...", applicability = "maybe-incorrect")]
     suggestion: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct NoApplicability {
     #[suggestion(typeck::suggestion, code = "...")]
     suggestion: Span,
@@ -476,14 +467,14 @@ struct NoApplicability {
 struct Note;
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound)]
+#[diag(typeck::ambiguous_lifetime_bound)]
 struct Subdiagnostic {
     #[subdiagnostic]
     note: Note,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct VecField {
     #[primary_span]
     #[label]
@@ -491,7 +482,7 @@ struct VecField {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct UnitField {
     #[primary_span]
     spans: Span,
@@ -502,7 +493,7 @@ struct UnitField {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct OptUnitField {
     #[primary_span]
     spans: Span,
@@ -513,7 +504,7 @@ struct OptUnitField {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct LabelWithTrailingPath {
     #[label(typeck::label, foo)]
     //~^ ERROR `#[label(...)]` is not a valid attribute
@@ -521,7 +512,7 @@ struct LabelWithTrailingPath {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct LabelWithTrailingNameValue {
     #[label(typeck::label, foo = "...")]
     //~^ ERROR `#[label(...)]` is not a valid attribute
@@ -529,40 +520,64 @@ struct LabelWithTrailingNameValue {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct LabelWithTrailingList {
     #[label(typeck::label, foo("..."))]
     //~^ ERROR `#[label(...)]` is not a valid attribute
     span: Span,
 }
 
-#[derive(SessionDiagnostic)]
-#[lint(typeck::ambiguous_lifetime_bound)]
-//~^ ERROR only `#[error(..)]` and `#[warning(..)]` are supported
-struct LintsBad {
-}
-
 #[derive(LintDiagnostic)]
-#[lint(typeck::ambiguous_lifetime_bound)]
+#[diag(typeck::ambiguous_lifetime_bound)]
 struct LintsGood {
 }
 
 #[derive(LintDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound)]
-//~^ ERROR only `#[lint(..)]` is supported
-struct ErrorsBad {
+#[diag(typeck::ambiguous_lifetime_bound)]
+struct PrimarySpanOnLint {
+    #[primary_span]
+    //~^ ERROR `#[primary_span]` is not a valid attribute
+    span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 struct ErrorWithMultiSpan {
     #[primary_span]
     span: MultiSpan,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+#[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 #[warn_]
 struct ErrorWithWarn {
     val: String,
 }
+
+#[derive(SessionDiagnostic)]
+#[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+//~^ ERROR `#[error(...)]` is not a valid attribute
+//~| ERROR diagnostic slug not specified
+//~| ERROR cannot find attribute `error` in this scope
+struct ErrorAttribute {}
+
+#[derive(SessionDiagnostic)]
+#[warning(typeck::ambiguous_lifetime_bound, code = "E0123")]
+//~^ ERROR `#[warning(...)]` is not a valid attribute
+//~| ERROR diagnostic slug not specified
+//~| ERROR cannot find attribute `warning` in this scope
+struct WarningAttribute {}
+
+#[derive(SessionDiagnostic)]
+#[lint(typeck::ambiguous_lifetime_bound, code = "E0123")]
+//~^ ERROR `#[lint(...)]` is not a valid attribute
+//~| ERROR diagnostic slug not specified
+//~| ERROR cannot find attribute `lint` in this scope
+struct LintAttributeOnSessionDiag {}
+
+#[derive(LintDiagnostic)]
+#[lint(typeck::ambiguous_lifetime_bound, code = "E0123")]
+//~^ ERROR `#[lint(...)]` is not a valid attribute
+//~| ERROR diagnostic slug not specified
+//~| ERROR cannot find attribute `lint` in this scope
+struct LintAttributeOnLintDiag {}
diff --git a/src/test/ui-fulldeps/session-diagnostic/diagnostic-derive.stderr b/src/test/ui-fulldeps/session-diagnostic/diagnostic-derive.stderr
index c1080aa24521f..866b1a1de999c 100644
--- a/src/test/ui-fulldeps/session-diagnostic/diagnostic-derive.stderr
+++ b/src/test/ui-fulldeps/session-diagnostic/diagnostic-derive.stderr
@@ -1,7 +1,7 @@
 error: `#[derive(SessionDiagnostic)]` can only be used on structs
   --> $DIR/diagnostic-derive.rs:39:1
    |
-LL | / #[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+LL | / #[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
 LL | |
 LL | | enum SessionDiagnosticOnEnum {
 LL | |     Foo,
@@ -9,11 +9,11 @@ LL | |     Bar,
 LL | | }
    | |_^
 
-error: `#[error = ...]` is not a valid attribute
+error: `#[diag = ...]` is not a valid attribute
   --> $DIR/diagnostic-derive.rs:48:1
    |
-LL | #[error = "E0123"]
-   | ^^^^^^^^^^^^^^^^^^
+LL | #[diag = "E0123"]
+   | ^^^^^^^^^^^^^^^^^
 
 error: `#[nonsense(...)]` is not a valid attribute
   --> $DIR/diagnostic-derive.rs:53:1
@@ -21,9 +21,9 @@ error: `#[nonsense(...)]` is not a valid attribute
 LL | #[nonsense(typeck::ambiguous_lifetime_bound, code = "E0123")]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = help: only `error`, `warning`, `help`, `note` and `warn_` are valid attributes
+   = help: only `diag`, `help`, `note` and `warn_` are valid attributes
 
-error: diagnostic kind not specified
+error: diagnostic slug not specified
   --> $DIR/diagnostic-derive.rs:53:1
    |
 LL | / #[nonsense(typeck::ambiguous_lifetime_bound, code = "E0123")]
@@ -33,89 +33,89 @@ LL | |
 LL | | struct InvalidStructAttr {}
    | |___________________________^
    |
-   = help: use the `#[error(...)]` attribute to create an error
+   = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(typeck::example_error)]`
 
-error: `#[error("...")]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:60:9
+error: `#[diag("...")]` is not a valid attribute
+  --> $DIR/diagnostic-derive.rs:60:8
    |
-LL | #[error("E0123")]
-   |         ^^^^^^^
+LL | #[diag("E0123")]
+   |        ^^^^^^^
    |
    = help: first argument of the attribute should be the diagnostic slug
 
 error: diagnostic slug not specified
   --> $DIR/diagnostic-derive.rs:60:1
    |
-LL | / #[error("E0123")]
+LL | / #[diag("E0123")]
 LL | |
 LL | |
 LL | | struct InvalidLitNestedAttr {}
    | |______________________________^
    |
-   = help: specify the slug as the first argument to the attribute, such as `#[error(typeck::example_error)]`
+   = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(typeck::example_error)]`
 
-error: `#[error(nonsense(...))]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:71:9
+error: `#[diag(nonsense(...))]` is not a valid attribute
+  --> $DIR/diagnostic-derive.rs:71:8
    |
-LL | #[error(nonsense("foo"), code = "E0123", slug = "foo")]
-   |         ^^^^^^^^^^^^^^^
+LL | #[diag(nonsense("foo"), code = "E0123", slug = "foo")]
+   |        ^^^^^^^^^^^^^^^
    |
    = help: first argument of the attribute should be the diagnostic slug
 
 error: diagnostic slug not specified
   --> $DIR/diagnostic-derive.rs:71:1
    |
-LL | / #[error(nonsense("foo"), code = "E0123", slug = "foo")]
+LL | / #[diag(nonsense("foo"), code = "E0123", slug = "foo")]
 LL | |
 LL | |
 LL | | struct InvalidNestedStructAttr1 {}
    | |__________________________________^
    |
-   = help: specify the slug as the first argument to the attribute, such as `#[error(typeck::example_error)]`
+   = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(typeck::example_error)]`
 
-error: `#[error(nonsense = ...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:77:9
+error: `#[diag(nonsense = ...)]` is not a valid attribute
+  --> $DIR/diagnostic-derive.rs:77:8
    |
-LL | #[error(nonsense = "...", code = "E0123", slug = "foo")]
-   |         ^^^^^^^^^^^^^^^^
+LL | #[diag(nonsense = "...", code = "E0123", slug = "foo")]
+   |        ^^^^^^^^^^^^^^^^
    |
    = help: first argument of the attribute should be the diagnostic slug
 
 error: diagnostic slug not specified
   --> $DIR/diagnostic-derive.rs:77:1
    |
-LL | / #[error(nonsense = "...", code = "E0123", slug = "foo")]
+LL | / #[diag(nonsense = "...", code = "E0123", slug = "foo")]
 LL | |
 LL | |
 LL | | struct InvalidNestedStructAttr2 {}
    | |__________________________________^
    |
-   = help: specify the slug as the first argument to the attribute, such as `#[error(typeck::example_error)]`
+   = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(typeck::example_error)]`
 
-error: `#[error(nonsense = ...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:83:9
+error: `#[diag(nonsense = ...)]` is not a valid attribute
+  --> $DIR/diagnostic-derive.rs:83:8
    |
-LL | #[error(nonsense = 4, code = "E0123", slug = "foo")]
-   |         ^^^^^^^^^^^^
+LL | #[diag(nonsense = 4, code = "E0123", slug = "foo")]
+   |        ^^^^^^^^^^^^
    |
    = help: first argument of the attribute should be the diagnostic slug
 
 error: diagnostic slug not specified
   --> $DIR/diagnostic-derive.rs:83:1
    |
-LL | / #[error(nonsense = 4, code = "E0123", slug = "foo")]
+LL | / #[diag(nonsense = 4, code = "E0123", slug = "foo")]
 LL | |
 LL | |
 LL | | struct InvalidNestedStructAttr3 {}
    | |__________________________________^
    |
-   = help: specify the slug as the first argument to the attribute, such as `#[error(typeck::example_error)]`
+   = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(typeck::example_error)]`
 
-error: `#[error(slug = ...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:89:59
+error: `#[diag(slug = ...)]` is not a valid attribute
+  --> $DIR/diagnostic-derive.rs:89:58
    |
-LL | #[error(typeck::ambiguous_lifetime_bound, code = "E0123", slug = "foo")]
-   |                                                           ^^^^^^^^^^^^
+LL | #[diag(typeck::ambiguous_lifetime_bound, code = "E0123", slug = "foo")]
+   |                                                          ^^^^^^^^^^^^
    |
    = help: only `code` is a valid nested attributes following the slug
 
@@ -128,119 +128,71 @@ LL |     #[suggestion = "bar"]
 error: specified multiple times
   --> $DIR/diagnostic-derive.rs:103:1
    |
-LL | #[error(typeck::ambiguous_lifetime_bound, code = "E0456")]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL | #[diag(typeck::ambiguous_lifetime_bound, code = "E0456")]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
 note: previously specified here
   --> $DIR/diagnostic-derive.rs:102:1
    |
-LL | #[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL | #[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: specified multiple times
-  --> $DIR/diagnostic-derive.rs:103:1
+  --> $DIR/diagnostic-derive.rs:103:49
    |
-LL | #[error(typeck::ambiguous_lifetime_bound, code = "E0456")]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL | #[diag(typeck::ambiguous_lifetime_bound, code = "E0456")]
+   |                                                 ^^^^^^^
    |
 note: previously specified here
-  --> $DIR/diagnostic-derive.rs:102:1
+  --> $DIR/diagnostic-derive.rs:102:49
    |
-LL | #[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL | #[diag(typeck::ambiguous_lifetime_bound, code = "E0123")]
+   |                                                 ^^^^^^^
 
 error: specified multiple times
-  --> $DIR/diagnostic-derive.rs:103:50
+  --> $DIR/diagnostic-derive.rs:109:65
    |
-LL | #[error(typeck::ambiguous_lifetime_bound, code = "E0456")]
-   |                                                  ^^^^^^^
+LL | #[diag(typeck::ambiguous_lifetime_bound, code = "E0456", code = "E0457")]
+   |                                                                 ^^^^^^^
    |
 note: previously specified here
-  --> $DIR/diagnostic-derive.rs:102:50
+  --> $DIR/diagnostic-derive.rs:109:49
    |
-LL | #[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
-   |                                                  ^^^^^^^
+LL | #[diag(typeck::ambiguous_lifetime_bound, code = "E0456", code = "E0457")]
+   |                                                 ^^^^^^^
 
-error: specified multiple times
-  --> $DIR/diagnostic-derive.rs:111:1
+error: `#[diag(typeck::ambiguous_lifetime_bound)]` is not a valid attribute
+  --> $DIR/diagnostic-derive.rs:114:42
    |
-LL | #[warning(typeck::ambiguous_lifetime_bound, code = "E0293")]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-note: previously specified here
-  --> $DIR/diagnostic-derive.rs:110:1
-   |
-LL | #[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL | #[diag(typeck::ambiguous_lifetime_bound, typeck::ambiguous_lifetime_bound, code = "E0456")]
+   |                                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: specified multiple times
-  --> $DIR/diagnostic-derive.rs:111:1
-   |
-LL | #[warning(typeck::ambiguous_lifetime_bound, code = "E0293")]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-note: previously specified here
-  --> $DIR/diagnostic-derive.rs:110:1
-   |
-LL | #[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-error: specified multiple times
-  --> $DIR/diagnostic-derive.rs:111:52
-   |
-LL | #[warning(typeck::ambiguous_lifetime_bound, code = "E0293")]
-   |                                                    ^^^^^^^
-   |
-note: previously specified here
-  --> $DIR/diagnostic-derive.rs:110:50
-   |
-LL | #[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
-   |                                                  ^^^^^^^
-
-error: specified multiple times
-  --> $DIR/diagnostic-derive.rs:118:66
-   |
-LL | #[error(typeck::ambiguous_lifetime_bound, code = "E0456", code = "E0457")]
-   |                                                                  ^^^^^^^
-   |
-note: previously specified here
-  --> $DIR/diagnostic-derive.rs:118:50
-   |
-LL | #[error(typeck::ambiguous_lifetime_bound, code = "E0456", code = "E0457")]
-   |                                                  ^^^^^^^
-
-error: `#[error(typeck::ambiguous_lifetime_bound)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:123:43
-   |
-LL | #[error(typeck::ambiguous_lifetime_bound, typeck::ambiguous_lifetime_bound, code = "E0456")]
-   |                                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-error: diagnostic kind not specified
-  --> $DIR/diagnostic-derive.rs:128:1
+error: diagnostic slug not specified
+  --> $DIR/diagnostic-derive.rs:119:1
    |
 LL | struct KindNotProvided {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = help: use the `#[error(...)]` attribute to create an error
+   = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(typeck::example_error)]`
 
 error: diagnostic slug not specified
-  --> $DIR/diagnostic-derive.rs:131:1
+  --> $DIR/diagnostic-derive.rs:122:1
    |
-LL | / #[error(code = "E0456")]
+LL | / #[diag(code = "E0456")]
 LL | |
 LL | | struct SlugNotProvided {}
    | |_________________________^
    |
-   = help: specify the slug as the first argument to the attribute, such as `#[error(typeck::example_error)]`
+   = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(typeck::example_error)]`
 
 error: the `#[primary_span]` attribute can only be applied to fields of type `Span` or `MultiSpan`
-  --> $DIR/diagnostic-derive.rs:142:5
+  --> $DIR/diagnostic-derive.rs:133:5
    |
 LL |     #[primary_span]
    |     ^^^^^^^^^^^^^^^
 
 error: `#[nonsense]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:150:5
+  --> $DIR/diagnostic-derive.rs:141:5
    |
 LL |     #[nonsense]
    |     ^^^^^^^^^^^
@@ -248,19 +200,19 @@ LL |     #[nonsense]
    = help: only `skip_arg`, `primary_span`, `label`, `note`, `help` and `subdiagnostic` are valid field attributes
 
 error: the `#[label(...)]` attribute can only be applied to fields of type `Span` or `MultiSpan`
-  --> $DIR/diagnostic-derive.rs:167:5
+  --> $DIR/diagnostic-derive.rs:158:5
    |
 LL |     #[label(typeck::label)]
    |     ^^^^^^^^^^^^^^^^^^^^^^^
 
 error: `name` doesn't refer to a field on this type
-  --> $DIR/diagnostic-derive.rs:175:45
+  --> $DIR/diagnostic-derive.rs:166:45
    |
 LL |     #[suggestion(typeck::suggestion, code = "{name}")]
    |                                             ^^^^^^^^
 
 error: invalid format string: expected `'}'` but string was terminated
-  --> $DIR/diagnostic-derive.rs:180:16
+  --> $DIR/diagnostic-derive.rs:171:16
    |
 LL | #[derive(SessionDiagnostic)]
    |           -    ^ expected `'}'` in format string
@@ -271,7 +223,7 @@ LL | #[derive(SessionDiagnostic)]
    = note: this error originates in the derive macro `SessionDiagnostic` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: invalid format string: unmatched `}` found
-  --> $DIR/diagnostic-derive.rs:190:15
+  --> $DIR/diagnostic-derive.rs:181:15
    |
 LL | #[derive(SessionDiagnostic)]
    |               ^ unmatched `}` in format string
@@ -280,13 +232,13 @@ LL | #[derive(SessionDiagnostic)]
    = note: this error originates in the derive macro `SessionDiagnostic` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: the `#[label(...)]` attribute can only be applied to fields of type `Span` or `MultiSpan`
-  --> $DIR/diagnostic-derive.rs:210:5
+  --> $DIR/diagnostic-derive.rs:201:5
    |
 LL |     #[label(typeck::label)]
    |     ^^^^^^^^^^^^^^^^^^^^^^^
 
 error: `#[suggestion(nonsense = ...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:235:18
+  --> $DIR/diagnostic-derive.rs:226:18
    |
 LL |     #[suggestion(nonsense = "bar")]
    |                  ^^^^^^^^^^^^^^^^
@@ -294,7 +246,7 @@ LL |     #[suggestion(nonsense = "bar")]
    = help: only `message`, `code` and `applicability` are valid field attributes
 
 error: `#[suggestion(msg = ...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:243:18
+  --> $DIR/diagnostic-derive.rs:234:18
    |
 LL |     #[suggestion(msg = "bar")]
    |                  ^^^^^^^^^^^
@@ -302,7 +254,7 @@ LL |     #[suggestion(msg = "bar")]
    = help: only `message`, `code` and `applicability` are valid field attributes
 
 error: wrong field type for suggestion
-  --> $DIR/diagnostic-derive.rs:265:5
+  --> $DIR/diagnostic-derive.rs:256:5
    |
 LL | /     #[suggestion(typeck::suggestion, code = "This is suggested code")]
 LL | |
@@ -312,7 +264,7 @@ LL | |     suggestion: Applicability,
    = help: `#[suggestion(...)]` should be applied to fields of type `Span` or `(Span, Applicability)`
 
 error: type of field annotated with `#[suggestion(...)]` contains more than one `Span`
-  --> $DIR/diagnostic-derive.rs:280:5
+  --> $DIR/diagnostic-derive.rs:271:5
    |
 LL | /     #[suggestion(typeck::suggestion, code = "This is suggested code")]
 LL | |
@@ -320,7 +272,7 @@ LL | |     suggestion: (Span, Span, Applicability),
    | |___________________________________________^
 
 error: type of field annotated with `#[suggestion(...)]` contains more than one Applicability
-  --> $DIR/diagnostic-derive.rs:288:5
+  --> $DIR/diagnostic-derive.rs:279:5
    |
 LL | /     #[suggestion(typeck::suggestion, code = "This is suggested code")]
 LL | |
@@ -328,62 +280,128 @@ LL | |     suggestion: (Applicability, Applicability, Span),
    | |____________________________________________________^
 
 error: `#[label = ...]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:296:5
+  --> $DIR/diagnostic-derive.rs:287:5
    |
 LL |     #[label = "bar"]
    |     ^^^^^^^^^^^^^^^^
 
 error: applicability cannot be set in both the field and attribute
-  --> $DIR/diagnostic-derive.rs:447:52
+  --> $DIR/diagnostic-derive.rs:438:52
    |
 LL |     #[suggestion(typeck::suggestion, code = "...", applicability = "maybe-incorrect")]
    |                                                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: invalid applicability
-  --> $DIR/diagnostic-derive.rs:455:52
+  --> $DIR/diagnostic-derive.rs:446:52
    |
 LL |     #[suggestion(typeck::suggestion, code = "...", applicability = "batman")]
    |                                                    ^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: `#[label(...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:518:5
+  --> $DIR/diagnostic-derive.rs:509:5
    |
 LL |     #[label(typeck::label, foo)]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: `#[label(...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:526:5
+  --> $DIR/diagnostic-derive.rs:517:5
    |
 LL |     #[label(typeck::label, foo = "...")]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: `#[label(...)]` is not a valid attribute
-  --> $DIR/diagnostic-derive.rs:534:5
+  --> $DIR/diagnostic-derive.rs:525:5
    |
 LL |     #[label(typeck::label, foo("..."))]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: only `#[error(..)]` and `#[warning(..)]` are supported
-  --> $DIR/diagnostic-derive.rs:540:1
+error: `#[primary_span]` is not a valid attribute
+  --> $DIR/diagnostic-derive.rs:538:5
    |
-LL | / #[lint(typeck::ambiguous_lifetime_bound)]
+LL |     #[primary_span]
+   |     ^^^^^^^^^^^^^^^
+   |
+   = help: the `primary_span` field attribute is not valid for lint diagnostics
+
+error: `#[error(...)]` is not a valid attribute
+  --> $DIR/diagnostic-derive.rs:558:1
+   |
+LL | #[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: `error`, `warning` and `lint` have been replaced by `diag`
+
+error: diagnostic slug not specified
+  --> $DIR/diagnostic-derive.rs:558:1
+   |
+LL | / #[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
 LL | |
-LL | | struct LintsBad {
-LL | | }
-   | |_^
+LL | |
+LL | |
+LL | | struct ErrorAttribute {}
+   | |________________________^
+   |
+   = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(typeck::example_error)]`
+
+error: `#[warning(...)]` is not a valid attribute
+  --> $DIR/diagnostic-derive.rs:565:1
    |
-   = help: use the `#[error(...)]` attribute to create a error
+LL | #[warning(typeck::ambiguous_lifetime_bound, code = "E0123")]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: `error`, `warning` and `lint` have been replaced by `diag`
 
-error: only `#[lint(..)]` is supported
-  --> $DIR/diagnostic-derive.rs:551:1
+error: diagnostic slug not specified
+  --> $DIR/diagnostic-derive.rs:565:1
    |
-LL | / #[error(typeck::ambiguous_lifetime_bound)]
+LL | / #[warning(typeck::ambiguous_lifetime_bound, code = "E0123")]
 LL | |
-LL | | struct ErrorsBad {
-LL | | }
-   | |_^
+LL | |
+LL | |
+LL | | struct WarningAttribute {}
+   | |__________________________^
+   |
+   = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(typeck::example_error)]`
+
+error: `#[lint(...)]` is not a valid attribute
+  --> $DIR/diagnostic-derive.rs:572:1
+   |
+LL | #[lint(typeck::ambiguous_lifetime_bound, code = "E0123")]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: `error`, `warning` and `lint` have been replaced by `diag`
+
+error: diagnostic slug not specified
+  --> $DIR/diagnostic-derive.rs:572:1
+   |
+LL | / #[lint(typeck::ambiguous_lifetime_bound, code = "E0123")]
+LL | |
+LL | |
+LL | |
+LL | | struct LintAttributeOnSessionDiag {}
+   | |____________________________________^
+   |
+   = help: specify the slug as the first argument to the `#[diag(...)]` attribute, such as `#[diag(typeck::example_error)]`
+
+error: `#[lint(...)]` is not a valid attribute
+  --> $DIR/diagnostic-derive.rs:579:1
+   |
+LL | #[lint(typeck::ambiguous_lifetime_bound, code = "E0123")]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: `error`, `warning` and `lint` have been replaced by `diag`
+
+error: diagnostic slug not specified
+  --> $DIR/diagnostic-derive.rs:579:1
+   |
+LL | / #[lint(typeck::ambiguous_lifetime_bound, code = "E0123")]
+LL | |
+LL | |
+LL | |
+LL | | struct LintAttributeOnLintDiag {}
+   | |_________________________________^
    |
-   = help: use the `#[lint(...)]` attribute to create a lint
+   = help: specify the slug as the first argument to the attribute, such as `#[diag(typeck::example_error)]`
 
 error: cannot find attribute `nonsense` in this scope
   --> $DIR/diagnostic-derive.rs:53:3
@@ -392,32 +410,56 @@ LL | #[nonsense(typeck::ambiguous_lifetime_bound, code = "E0123")]
    |   ^^^^^^^^
 
 error: cannot find attribute `nonsense` in this scope
-  --> $DIR/diagnostic-derive.rs:150:7
+  --> $DIR/diagnostic-derive.rs:141:7
    |
 LL |     #[nonsense]
    |       ^^^^^^^^
 
+error: cannot find attribute `error` in this scope
+  --> $DIR/diagnostic-derive.rs:558:3
+   |
+LL | #[error(typeck::ambiguous_lifetime_bound, code = "E0123")]
+   |   ^^^^^
+
+error: cannot find attribute `warning` in this scope
+  --> $DIR/diagnostic-derive.rs:565:3
+   |
+LL | #[warning(typeck::ambiguous_lifetime_bound, code = "E0123")]
+   |   ^^^^^^^
+
+error: cannot find attribute `lint` in this scope
+  --> $DIR/diagnostic-derive.rs:572:3
+   |
+LL | #[lint(typeck::ambiguous_lifetime_bound, code = "E0123")]
+   |   ^^^^ help: a built-in attribute with a similar name exists: `link`
+
+error: cannot find attribute `lint` in this scope
+  --> $DIR/diagnostic-derive.rs:579:3
+   |
+LL | #[lint(typeck::ambiguous_lifetime_bound, code = "E0123")]
+   |   ^^^^ help: a built-in attribute with a similar name exists: `link`
+
 error[E0425]: cannot find value `nonsense` in module `rustc_errors::fluent`
-  --> $DIR/diagnostic-derive.rs:66:9
+  --> $DIR/diagnostic-derive.rs:66:8
    |
-LL | #[error(nonsense, code = "E0123")]
-   |         ^^^^^^^^ not found in `rustc_errors::fluent`
+LL | #[diag(nonsense, code = "E0123")]
+   |        ^^^^^^^^ not found in `rustc_errors::fluent`
 
 error[E0277]: the trait bound `Hello: IntoDiagnosticArg` is not satisfied
-  --> $DIR/diagnostic-derive.rs:340:10
+  --> $DIR/diagnostic-derive.rs:331:10
    |
 LL | #[derive(SessionDiagnostic)]
    |          ^^^^^^^^^^^^^^^^^ the trait `IntoDiagnosticArg` is not implemented for `Hello`
    |
    = help: normalized in stderr
 note: required by a bound in `DiagnosticBuilder::<'a, G>::set_arg`
-  --> $COMPILER_DIR/rustc_errors/src/diagnostic_builder.rs:539:19
+  --> $COMPILER_DIR/rustc_errors/src/diagnostic_builder.rs:569:19
    |
 LL |         arg: impl IntoDiagnosticArg,
    |                   ^^^^^^^^^^^^^^^^^ required by this bound in `DiagnosticBuilder::<'a, G>::set_arg`
    = note: this error originates in the derive macro `SessionDiagnostic` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: aborting due to 48 previous errors
+error: aborting due to 55 previous errors
 
 Some errors have detailed explanations: E0277, E0425.
 For more information about an error, try `rustc --explain E0277`.
diff --git a/src/test/ui/associated-types/associated-types-eq-3.stderr b/src/test/ui/associated-types/associated-types-eq-3.stderr
index 19750fe1f333f..fbe1a1ee8bcd7 100644
--- a/src/test/ui/associated-types/associated-types-eq-3.stderr
+++ b/src/test/ui/associated-types/associated-types-eq-3.stderr
@@ -36,9 +36,7 @@ error[E0271]: type mismatch resolving `<isize as Foo>::A == Bar`
   --> $DIR/associated-types-eq-3.rs:40:9
    |
 LL |     baz(&a);
-   |     --- ^^ type mismatch resolving `<isize as Foo>::A == Bar`
-   |     |
-   |     required by a bound introduced by this call
+   |         ^^ type mismatch resolving `<isize as Foo>::A == Bar`
    |
 note: expected this to be `Bar`
   --> $DIR/associated-types-eq-3.rs:12:14
diff --git a/src/test/ui/associated-types/associated-types-path-2.stderr b/src/test/ui/associated-types/associated-types-path-2.stderr
index 66f1ab726922d..5edd5c864e135 100644
--- a/src/test/ui/associated-types/associated-types-path-2.stderr
+++ b/src/test/ui/associated-types/associated-types-path-2.stderr
@@ -17,10 +17,12 @@ LL |     f1(2i32, 4u32);
    |               ~~~
 
 error[E0277]: the trait bound `u32: Foo` is not satisfied
-  --> $DIR/associated-types-path-2.rs:29:5
+  --> $DIR/associated-types-path-2.rs:29:8
    |
 LL |     f1(2u32, 4u32);
-   |     ^^ the trait `Foo` is not implemented for `u32`
+   |     -- ^^^^ the trait `Foo` is not implemented for `u32`
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: the trait `Foo` is implemented for `i32`
 note: required by a bound in `f1`
@@ -33,9 +35,7 @@ error[E0277]: the trait bound `u32: Foo` is not satisfied
   --> $DIR/associated-types-path-2.rs:29:14
    |
 LL |     f1(2u32, 4u32);
-   |     --       ^^^^ the trait `Foo` is not implemented for `u32`
-   |     |
-   |     required by a bound introduced by this call
+   |              ^^^^ the trait `Foo` is not implemented for `u32`
    |
    = help: the trait `Foo` is implemented for `i32`
 
diff --git a/src/test/ui/associated-types/issue-27675-unchecked-bounds.stderr b/src/test/ui/associated-types/issue-27675-unchecked-bounds.stderr
index 22daaf329102a..a14a273b3ece9 100644
--- a/src/test/ui/associated-types/issue-27675-unchecked-bounds.stderr
+++ b/src/test/ui/associated-types/issue-27675-unchecked-bounds.stderr
@@ -1,10 +1,8 @@
 error[E0277]: the trait bound `T: Copy` is not satisfied
-  --> $DIR/issue-27675-unchecked-bounds.rs:15:31
+  --> $DIR/issue-27675-unchecked-bounds.rs:15:12
    |
 LL |     copy::<dyn Setup<From=T>>(t)
-   |     ------------------------- ^ the trait `Copy` is not implemented for `T`
-   |     |
-   |     required by a bound introduced by this call
+   |            ^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `T`
    |
 note: required by a bound in `copy`
   --> $DIR/issue-27675-unchecked-bounds.rs:10:12
diff --git a/src/test/ui/async-await/issue-67252-unnamed-future.stderr b/src/test/ui/async-await/issue-67252-unnamed-future.stderr
index 01c0d3225ba0b..af99b608ca14d 100644
--- a/src/test/ui/async-await/issue-67252-unnamed-future.stderr
+++ b/src/test/ui/async-await/issue-67252-unnamed-future.stderr
@@ -1,8 +1,12 @@
 error: future cannot be sent between threads safely
-  --> $DIR/issue-67252-unnamed-future.rs:18:5
+  --> $DIR/issue-67252-unnamed-future.rs:18:11
    |
-LL |     spawn(async {
-   |     ^^^^^ future created by async block is not `Send`
+LL |       spawn(async {
+   |  ___________^
+LL | |         let _a = std::ptr::null_mut::<()>(); // `*mut ()` is not `Send`
+LL | |         AFuture.await;
+LL | |     });
+   | |_____^ future created by async block is not `Send`
    |
    = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `*mut ()`
 note: future is not `Send` as this value is used across an await
diff --git a/src/test/ui/async-await/issue-68112.stderr b/src/test/ui/async-await/issue-68112.stderr
index 9c85eb8768497..c3553e3e0c1c2 100644
--- a/src/test/ui/async-await/issue-68112.stderr
+++ b/src/test/ui/async-await/issue-68112.stderr
@@ -1,8 +1,8 @@
 error: future cannot be sent between threads safely
-  --> $DIR/issue-68112.rs:34:5
+  --> $DIR/issue-68112.rs:34:18
    |
 LL |     require_send(send_fut);
-   |     ^^^^^^^^^^^^ future created by async block is not `Send`
+   |                  ^^^^^^^^ future created by async block is not `Send`
    |
    = help: the trait `Sync` is not implemented for `RefCell<i32>`
 note: future is not `Send` as it awaits another future which is not `Send`
@@ -17,10 +17,10 @@ LL | fn require_send(_: impl Send) {}
    |                         ^^^^ required by this bound in `require_send`
 
 error: future cannot be sent between threads safely
-  --> $DIR/issue-68112.rs:43:5
+  --> $DIR/issue-68112.rs:43:18
    |
 LL |     require_send(send_fut);
-   |     ^^^^^^^^^^^^ future created by async block is not `Send`
+   |                  ^^^^^^^^ future created by async block is not `Send`
    |
    = help: the trait `Sync` is not implemented for `RefCell<i32>`
 note: future is not `Send` as it awaits another future which is not `Send`
@@ -35,10 +35,12 @@ LL | fn require_send(_: impl Send) {}
    |                         ^^^^ required by this bound in `require_send`
 
 error[E0277]: `RefCell<i32>` cannot be shared between threads safely
-  --> $DIR/issue-68112.rs:60:5
+  --> $DIR/issue-68112.rs:60:18
    |
 LL |     require_send(send_fut);
-   |     ^^^^^^^^^^^^ `RefCell<i32>` cannot be shared between threads safely
+   |     ------------ ^^^^^^^^ `RefCell<i32>` cannot be shared between threads safely
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: the trait `Sync` is not implemented for `RefCell<i32>`
    = note: required for `Arc<RefCell<i32>>` to implement `Send`
diff --git a/src/test/ui/async-await/issues/issue-65436-raw-ptr-not-send.stderr b/src/test/ui/async-await/issues/issue-65436-raw-ptr-not-send.stderr
index b230930012914..99e960f5d0f26 100644
--- a/src/test/ui/async-await/issues/issue-65436-raw-ptr-not-send.stderr
+++ b/src/test/ui/async-await/issues/issue-65436-raw-ptr-not-send.stderr
@@ -1,8 +1,12 @@
 error: future cannot be sent between threads safely
-  --> $DIR/issue-65436-raw-ptr-not-send.rs:12:5
+  --> $DIR/issue-65436-raw-ptr-not-send.rs:12:17
    |
-LL |     assert_send(async {
-   |     ^^^^^^^^^^^ future created by async block is not `Send`
+LL |       assert_send(async {
+   |  _________________^
+LL | |
+LL | |         bar(Foo(std::ptr::null())).await;
+LL | |     })
+   | |_____^ future created by async block is not `Send`
    |
    = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `*const u8`
 note: future is not `Send` as this value is used across an await
diff --git a/src/test/ui/auto-traits/typeck-default-trait-impl-constituent-types-2.stderr b/src/test/ui/auto-traits/typeck-default-trait-impl-constituent-types-2.stderr
index 7d6bf58f51696..0c4970a72591f 100644
--- a/src/test/ui/auto-traits/typeck-default-trait-impl-constituent-types-2.stderr
+++ b/src/test/ui/auto-traits/typeck-default-trait-impl-constituent-types-2.stderr
@@ -1,8 +1,8 @@
 error[E0277]: the trait bound `MyS2: MyTrait` is not satisfied in `(MyS2, MyS)`
-  --> $DIR/typeck-default-trait-impl-constituent-types-2.rs:17:5
+  --> $DIR/typeck-default-trait-impl-constituent-types-2.rs:17:18
    |
 LL |     is_mytrait::<(MyS2, MyS)>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^ within `(MyS2, MyS)`, the trait `MyTrait` is not implemented for `MyS2`
+   |                  ^^^^^^^^^^^ within `(MyS2, MyS)`, the trait `MyTrait` is not implemented for `MyS2`
    |
    = note: required because it appears within the type `(MyS2, MyS)`
 note: required by a bound in `is_mytrait`
diff --git a/src/test/ui/auto-traits/typeck-default-trait-impl-precedence.stderr b/src/test/ui/auto-traits/typeck-default-trait-impl-precedence.stderr
index 5645e15850274..ce7095664c11a 100644
--- a/src/test/ui/auto-traits/typeck-default-trait-impl-precedence.stderr
+++ b/src/test/ui/auto-traits/typeck-default-trait-impl-precedence.stderr
@@ -1,8 +1,8 @@
 error[E0277]: the trait bound `u32: Signed` is not satisfied
-  --> $DIR/typeck-default-trait-impl-precedence.rs:19:5
+  --> $DIR/typeck-default-trait-impl-precedence.rs:19:20
    |
 LL |     is_defaulted::<&'static u32>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Signed` is not implemented for `u32`
+   |                    ^^^^^^^^^^^^ the trait `Signed` is not implemented for `u32`
    |
    = help: the trait `Signed` is implemented for `i32`
 note: required for `&'static u32` to implement `Defaulted`
diff --git a/src/test/ui/chalkify/type_wf.rs b/src/test/ui/chalkify/type_wf.rs
index dd83a03fdf691..eeeefcfb7dd15 100644
--- a/src/test/ui/chalkify/type_wf.rs
+++ b/src/test/ui/chalkify/type_wf.rs
@@ -15,8 +15,8 @@ fn main() {
        x: 5,
     };
 
-    let s = S { //~ ERROR the trait bound `{float}: Foo` is not satisfied
-        x: 5.0,
+    let s = S {
+        x: 5.0, //~ ERROR the trait bound `{float}: Foo` is not satisfied
     };
 
     let s = S {
diff --git a/src/test/ui/chalkify/type_wf.stderr b/src/test/ui/chalkify/type_wf.stderr
index 7f8566082cd26..6e8daf635175f 100644
--- a/src/test/ui/chalkify/type_wf.stderr
+++ b/src/test/ui/chalkify/type_wf.stderr
@@ -1,8 +1,8 @@
 error[E0277]: the trait bound `{float}: Foo` is not satisfied
-  --> $DIR/type_wf.rs:18:13
+  --> $DIR/type_wf.rs:19:12
    |
-LL |     let s = S {
-   |             ^ the trait `Foo` is not implemented for `{float}`
+LL |         x: 5.0,
+   |            ^^^ the trait `Foo` is not implemented for `{float}`
    |
    = help: the trait `Foo` is implemented for `i32`
 note: required by a bound in `S`
diff --git a/src/test/ui/closure_context/issue-26046-fn-mut.stderr b/src/test/ui/closure_context/issue-26046-fn-mut.stderr
index 74d3c4977ee65..f744b71c284b0 100644
--- a/src/test/ui/closure_context/issue-26046-fn-mut.stderr
+++ b/src/test/ui/closure_context/issue-26046-fn-mut.stderr
@@ -8,6 +8,8 @@ LL |         num += 1;
 ...
 LL |     Box::new(closure)
    |     ----------------- the requirement to implement `Fn` derives from here
+   |
+   = note: required for the cast from `[closure@$DIR/issue-26046-fn-mut.rs:4:19: 4:21]` to the object type `dyn Fn()`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/closure_context/issue-26046-fn-once.stderr b/src/test/ui/closure_context/issue-26046-fn-once.stderr
index 473e8e8417e6e..34f94f9dca6d3 100644
--- a/src/test/ui/closure_context/issue-26046-fn-once.stderr
+++ b/src/test/ui/closure_context/issue-26046-fn-once.stderr
@@ -8,6 +8,8 @@ LL |         vec
 ...
 LL |     Box::new(closure)
    |     ----------------- the requirement to implement `Fn` derives from here
+   |
+   = note: required for the cast from `[closure@$DIR/issue-26046-fn-once.rs:4:19: 4:26]` to the object type `dyn Fn() -> Vec<u8>`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-array-diagnostics.stderr b/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-array-diagnostics.stderr
index bcde35983fc4c..309c63e52932b 100644
--- a/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-array-diagnostics.stderr
+++ b/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-array-diagnostics.stderr
@@ -7,7 +7,15 @@ LL |         let [_, _s] = s;
    |                       - closure is `FnOnce` because it moves the variable `s` out of its environment
 LL |     };
 LL |     expect_fn(c);
-   |     --------- the requirement to implement `Fn` derives from here
+   |     --------- - the requirement to implement `Fn` derives from here
+   |     |
+   |     required by a bound introduced by this call
+   |
+note: required by a bound in `expect_fn`
+  --> $DIR/closure-origin-array-diagnostics.rs:5:17
+   |
+LL | fn expect_fn<F: Fn()>(_f: F) {}
+   |                 ^^^^ required by this bound in `expect_fn`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-tuple-diagnostics.stderr b/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-tuple-diagnostics.stderr
index df33c4f1fd6d4..3e77635f9e0c8 100644
--- a/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-tuple-diagnostics.stderr
+++ b/src/test/ui/closures/2229_closure_analysis/diagnostics/closure-origin-tuple-diagnostics.stderr
@@ -7,7 +7,15 @@ LL |         let s = s.1;
    |                 --- closure is `FnOnce` because it moves the variable `s.1` out of its environment
 LL |     };
 LL |     expect_fn(c);
-   |     --------- the requirement to implement `Fn` derives from here
+   |     --------- - the requirement to implement `Fn` derives from here
+   |     |
+   |     required by a bound introduced by this call
+   |
+note: required by a bound in `expect_fn`
+  --> $DIR/closure-origin-tuple-diagnostics.rs:5:17
+   |
+LL | fn expect_fn<F: Fn()>(_f: F) {}
+   |                 ^^^^ required by this bound in `expect_fn`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/closures/closure-move-sync.stderr b/src/test/ui/closures/closure-move-sync.stderr
index 3e9b1c292dc18..a2ca06b4e6e1a 100644
--- a/src/test/ui/closures/closure-move-sync.stderr
+++ b/src/test/ui/closures/closure-move-sync.stderr
@@ -1,8 +1,14 @@
 error[E0277]: `std::sync::mpsc::Receiver<()>` cannot be shared between threads safely
-  --> $DIR/closure-move-sync.rs:6:13
+  --> $DIR/closure-move-sync.rs:6:27
    |
-LL |     let t = thread::spawn(|| {
-   |             ^^^^^^^^^^^^^ `std::sync::mpsc::Receiver<()>` cannot be shared between threads safely
+LL |       let t = thread::spawn(|| {
+   |  _____________-------------_^
+   | |             |
+   | |             required by a bound introduced by this call
+LL | |         recv.recv().unwrap();
+LL | |
+LL | |     });
+   | |_____^ `std::sync::mpsc::Receiver<()>` cannot be shared between threads safely
    |
    = help: the trait `Sync` is not implemented for `std::sync::mpsc::Receiver<()>`
    = note: required for `&std::sync::mpsc::Receiver<()>` to implement `Send`
@@ -18,10 +24,12 @@ LL |     F: Send + 'static,
    |        ^^^^ required by this bound in `spawn`
 
 error[E0277]: `Sender<()>` cannot be shared between threads safely
-  --> $DIR/closure-move-sync.rs:18:5
+  --> $DIR/closure-move-sync.rs:18:19
    |
 LL |     thread::spawn(|| tx.send(()).unwrap());
-   |     ^^^^^^^^^^^^^ `Sender<()>` cannot be shared between threads safely
+   |     ------------- ^^^^^^^^^^^^^^^^^^^^^^^ `Sender<()>` cannot be shared between threads safely
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: the trait `Sync` is not implemented for `Sender<()>`
    = note: required for `&Sender<()>` to implement `Send`
diff --git a/src/test/ui/closures/closure-wrong-kind.stderr b/src/test/ui/closures/closure-wrong-kind.stderr
index 35caf71a5e8c7..9ea55d764f345 100644
--- a/src/test/ui/closures/closure-wrong-kind.stderr
+++ b/src/test/ui/closures/closure-wrong-kind.stderr
@@ -6,7 +6,15 @@ LL |     let closure = |_| foo(x);
    |                   |
    |                   this closure implements `FnOnce`, not `Fn`
 LL |     bar(closure);
-   |     --- the requirement to implement `Fn` derives from here
+   |     --- ------- the requirement to implement `Fn` derives from here
+   |     |
+   |     required by a bound introduced by this call
+   |
+note: required by a bound in `bar`
+  --> $DIR/closure-wrong-kind.rs:6:11
+   |
+LL | fn bar<T: Fn(u32)>(_: T) {}
+   |           ^^^^^^^ required by this bound in `bar`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/const-generics/defaults/trait_objects_fail.stderr b/src/test/ui/const-generics/defaults/trait_objects_fail.stderr
index a9c185e5fcbd1..0e8334d033820 100644
--- a/src/test/ui/const-generics/defaults/trait_objects_fail.stderr
+++ b/src/test/ui/const-generics/defaults/trait_objects_fail.stderr
@@ -2,9 +2,7 @@ error[E0277]: the trait bound `u32: Trait` is not satisfied
   --> $DIR/trait_objects_fail.rs:26:9
    |
 LL |     foo(&10_u32);
-   |     --- ^^^^^^^ the trait `Trait` is not implemented for `u32`
-   |     |
-   |     required by a bound introduced by this call
+   |         ^^^^^^^ the trait `Trait` is not implemented for `u32`
    |
    = help: the trait `Trait<2>` is implemented for `u32`
    = note: required for the cast from `u32` to the object type `dyn Trait`
@@ -13,9 +11,7 @@ error[E0277]: the trait bound `bool: Traitor<_>` is not satisfied
   --> $DIR/trait_objects_fail.rs:28:9
    |
 LL |     bar(&true);
-   |     --- ^^^^^ the trait `Traitor<_>` is not implemented for `bool`
-   |     |
-   |     required by a bound introduced by this call
+   |         ^^^^^ the trait `Traitor<_>` is not implemented for `bool`
    |
    = help: the trait `Traitor<2, 3>` is implemented for `bool`
    = note: required for the cast from `bool` to the object type `dyn Traitor<_>`
diff --git a/src/test/ui/const-generics/generic_const_exprs/abstract-const-as-cast-3.stderr b/src/test/ui/const-generics/generic_const_exprs/abstract-const-as-cast-3.stderr
index a5f7bc0b26cbd..615dc875f67a3 100644
--- a/src/test/ui/const-generics/generic_const_exprs/abstract-const-as-cast-3.stderr
+++ b/src/test/ui/const-generics/generic_const_exprs/abstract-const-as-cast-3.stderr
@@ -1,8 +1,8 @@
 error: unconstrained generic constant
-  --> $DIR/abstract-const-as-cast-3.rs:17:5
+  --> $DIR/abstract-const-as-cast-3.rs:17:19
    |
 LL |     assert_impl::<HasCastInTraitImpl<{ N + 1 }, { N as u128 }>>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: try adding a `where` bound using this expression: `where [(); { O as u128 }]:`
 note: required for `HasCastInTraitImpl<{ N + 1 }, { N as u128 }>` to implement `Trait`
@@ -26,10 +26,10 @@ LL |     assert_impl::<HasCastInTraitImpl<{ N + 1 }, { N as u128 }>>();
               found type `{ O as u128 }`
 
 error: unconstrained generic constant
-  --> $DIR/abstract-const-as-cast-3.rs:20:5
+  --> $DIR/abstract-const-as-cast-3.rs:20:19
    |
 LL |     assert_impl::<HasCastInTraitImpl<{ N + 1 }, { N as _ }>>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: try adding a `where` bound using this expression: `where [(); { O as u128 }]:`
 note: required for `HasCastInTraitImpl<{ N + 1 }, { N as _ }>` to implement `Trait`
@@ -71,10 +71,10 @@ LL |     assert_impl::<HasCastInTraitImpl<14, 13>>();
               found type `14`
 
 error: unconstrained generic constant
-  --> $DIR/abstract-const-as-cast-3.rs:35:5
+  --> $DIR/abstract-const-as-cast-3.rs:35:19
    |
 LL |     assert_impl::<HasCastInTraitImpl<{ N + 1 }, { N as u128 }>>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: try adding a `where` bound using this expression: `where [(); { O as u128 }]:`
 note: required for `HasCastInTraitImpl<{ N + 1 }, { N as u128 }>` to implement `Trait`
@@ -98,10 +98,10 @@ LL |     assert_impl::<HasCastInTraitImpl<{ N + 1 }, { N as u128 }>>();
               found type `{ O as u128 }`
 
 error: unconstrained generic constant
-  --> $DIR/abstract-const-as-cast-3.rs:38:5
+  --> $DIR/abstract-const-as-cast-3.rs:38:19
    |
 LL |     assert_impl::<HasCastInTraitImpl<{ N + 1 }, { N as _ }>>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: try adding a `where` bound using this expression: `where [(); { O as u128 }]:`
 note: required for `HasCastInTraitImpl<{ N + 1 }, { N as _ }>` to implement `Trait`
diff --git a/src/test/ui/consts/const-block-const-bound.stderr b/src/test/ui/consts/const-block-const-bound.stderr
index 87ca771e54ed4..b9c4d8866bf9d 100644
--- a/src/test/ui/consts/const-block-const-bound.stderr
+++ b/src/test/ui/consts/const-block-const-bound.stderr
@@ -2,7 +2,7 @@ error[E0277]: can't drop `UnconstDrop` in const contexts
   --> $DIR/const-block-const-bound.rs:20:11
    |
 LL |         f(UnconstDrop);
-   |         - ^^^^^^^^^^^ expected an implementor of trait `~const Destruct`
+   |         - ^^^^^^^^^^^ the trait `~const Destruct` is not implemented for `UnconstDrop`
    |         |
    |         required by a bound introduced by this call
    |
@@ -23,7 +23,7 @@ error[E0277]: can't drop `NonDrop` in const contexts
   --> $DIR/const-block-const-bound.rs:22:11
    |
 LL |         f(NonDrop);
-   |         - ^^^^^^^ expected an implementor of trait `~const Destruct`
+   |         - ^^^^^^^ the trait `~const Destruct` is not implemented for `NonDrop`
    |         |
    |         required by a bound introduced by this call
    |
diff --git a/src/test/ui/derives/deriving-copyclone.stderr b/src/test/ui/derives/deriving-copyclone.stderr
index da895098e4b8e..80e2dd7fedefd 100644
--- a/src/test/ui/derives/deriving-copyclone.stderr
+++ b/src/test/ui/derives/deriving-copyclone.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `B<C>: Copy` is not satisfied
   --> $DIR/deriving-copyclone.rs:31:13
    |
 LL |     is_copy(B { a: 1, b: C });
-   |     ------- ^^^^^^^^^^^^^^^^ expected an implementor of trait `Copy`
+   |     ------- ^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `B<C>`
    |     |
    |     required by a bound introduced by this call
    |
@@ -26,7 +26,7 @@ error[E0277]: the trait bound `B<C>: Clone` is not satisfied
   --> $DIR/deriving-copyclone.rs:32:14
    |
 LL |     is_clone(B { a: 1, b: C });
-   |     -------- ^^^^^^^^^^^^^^^^ expected an implementor of trait `Clone`
+   |     -------- ^^^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `B<C>`
    |     |
    |     required by a bound introduced by this call
    |
@@ -50,7 +50,7 @@ error[E0277]: the trait bound `B<D>: Copy` is not satisfied
   --> $DIR/deriving-copyclone.rs:35:13
    |
 LL |     is_copy(B { a: 1, b: D });
-   |     ------- ^^^^^^^^^^^^^^^^ expected an implementor of trait `Copy`
+   |     ------- ^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `B<D>`
    |     |
    |     required by a bound introduced by this call
    |
diff --git a/src/test/ui/did_you_mean/issue-21659-show-relevant-trait-impls-1.stderr b/src/test/ui/did_you_mean/issue-21659-show-relevant-trait-impls-1.stderr
index 26764bc0ee5cc..b69fcd5d32a60 100644
--- a/src/test/ui/did_you_mean/issue-21659-show-relevant-trait-impls-1.stderr
+++ b/src/test/ui/did_you_mean/issue-21659-show-relevant-trait-impls-1.stderr
@@ -1,8 +1,10 @@
 error[E0277]: the trait bound `Bar: Foo<usize>` is not satisfied
-  --> $DIR/issue-21659-show-relevant-trait-impls-1.rs:24:8
+  --> $DIR/issue-21659-show-relevant-trait-impls-1.rs:24:12
    |
 LL |     f1.foo(1usize);
-   |        ^^^ the trait `Foo<usize>` is not implemented for `Bar`
+   |        --- ^^^^^^ the trait `Foo<usize>` is not implemented for `Bar`
+   |        |
+   |        required by a bound introduced by this call
    |
    = help: the following other types implement trait `Foo<A>`:
              <Bar as Foo<i32>>
diff --git a/src/test/ui/did_you_mean/issue-21659-show-relevant-trait-impls-2.stderr b/src/test/ui/did_you_mean/issue-21659-show-relevant-trait-impls-2.stderr
index bb175367e1f9e..5e0e4a0115a0e 100644
--- a/src/test/ui/did_you_mean/issue-21659-show-relevant-trait-impls-2.stderr
+++ b/src/test/ui/did_you_mean/issue-21659-show-relevant-trait-impls-2.stderr
@@ -1,8 +1,10 @@
 error[E0277]: the trait bound `Bar: Foo<usize>` is not satisfied
-  --> $DIR/issue-21659-show-relevant-trait-impls-2.rs:28:8
+  --> $DIR/issue-21659-show-relevant-trait-impls-2.rs:28:12
    |
 LL |     f1.foo(1usize);
-   |        ^^^ the trait `Foo<usize>` is not implemented for `Bar`
+   |        --- ^^^^^^ the trait `Foo<usize>` is not implemented for `Bar`
+   |        |
+   |        required by a bound introduced by this call
    |
    = help: the following other types implement trait `Foo<A>`:
              <Bar as Foo<i16>>
diff --git a/src/test/ui/error-codes/E0277-2.stderr b/src/test/ui/error-codes/E0277-2.stderr
index ca2cb88424076..a2abf37931a4f 100644
--- a/src/test/ui/error-codes/E0277-2.stderr
+++ b/src/test/ui/error-codes/E0277-2.stderr
@@ -1,8 +1,8 @@
 error[E0277]: `*const u8` cannot be sent between threads safely
-  --> $DIR/E0277-2.rs:16:5
+  --> $DIR/E0277-2.rs:16:15
    |
 LL |     is_send::<Foo>();
-   |     ^^^^^^^^^^^^^^ `*const u8` cannot be sent between threads safely
+   |               ^^^ `*const u8` cannot be sent between threads safely
    |
    = help: within `Foo`, the trait `Send` is not implemented for `*const u8`
 note: required because it appears within the type `Baz`
diff --git a/src/test/ui/extern/extern-types-unsized.stderr b/src/test/ui/extern/extern-types-unsized.stderr
index 8d6713261d5ec..a79caced111bb 100644
--- a/src/test/ui/extern/extern-types-unsized.stderr
+++ b/src/test/ui/extern/extern-types-unsized.stderr
@@ -16,10 +16,10 @@ LL | fn assert_sized<T: ?Sized>() {}
    |                  ++++++++
 
 error[E0277]: the size for values of type `A` cannot be known at compilation time
-  --> $DIR/extern-types-unsized.rs:25:5
+  --> $DIR/extern-types-unsized.rs:25:20
    |
 LL |     assert_sized::<Foo>();
-   |     ^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
+   |                    ^^^ doesn't have a size known at compile-time
    |
    = help: within `Foo`, the trait `Sized` is not implemented for `A`
 note: required because it appears within the type `Foo`
@@ -38,10 +38,10 @@ LL | fn assert_sized<T: ?Sized>() {}
    |                  ++++++++
 
 error[E0277]: the size for values of type `A` cannot be known at compilation time
-  --> $DIR/extern-types-unsized.rs:28:5
+  --> $DIR/extern-types-unsized.rs:28:20
    |
 LL |     assert_sized::<Bar<A>>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
+   |                    ^^^^^^ doesn't have a size known at compile-time
    |
    = help: within `Bar<A>`, the trait `Sized` is not implemented for `A`
 note: required because it appears within the type `Bar<A>`
@@ -60,10 +60,10 @@ LL | fn assert_sized<T: ?Sized>() {}
    |                  ++++++++
 
 error[E0277]: the size for values of type `A` cannot be known at compilation time
-  --> $DIR/extern-types-unsized.rs:31:5
+  --> $DIR/extern-types-unsized.rs:31:20
    |
 LL |     assert_sized::<Bar<Bar<A>>>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
+   |                    ^^^^^^^^^^^ doesn't have a size known at compile-time
    |
    = help: within `Bar<Bar<A>>`, the trait `Sized` is not implemented for `A`
 note: required because it appears within the type `Bar<A>`
diff --git a/src/test/ui/feature-gates/feature-gate-unsized_fn_params.stderr b/src/test/ui/feature-gates/feature-gate-unsized_fn_params.stderr
index 0557340f792fd..b7757740d9e34 100644
--- a/src/test/ui/feature-gates/feature-gate-unsized_fn_params.stderr
+++ b/src/test/ui/feature-gates/feature-gate-unsized_fn_params.stderr
@@ -15,9 +15,7 @@ error[E0277]: the size for values of type `(dyn Foo + 'static)` cannot be known
   --> $DIR/feature-gate-unsized_fn_params.rs:24:9
    |
 LL |     foo(*x);
-   |     --- ^^ doesn't have a size known at compile-time
-   |     |
-   |     required by a bound introduced by this call
+   |         ^^ doesn't have a size known at compile-time
    |
    = help: the trait `Sized` is not implemented for `(dyn Foo + 'static)`
    = help: unsized fn params are gated as an unstable feature
diff --git a/src/test/ui/fmt/send-sync.stderr b/src/test/ui/fmt/send-sync.stderr
index 726d3e35b10e9..3ed040c3ab359 100644
--- a/src/test/ui/fmt/send-sync.stderr
+++ b/src/test/ui/fmt/send-sync.stderr
@@ -1,8 +1,10 @@
 error[E0277]: `core::fmt::Opaque` cannot be shared between threads safely
-  --> $DIR/send-sync.rs:8:5
+  --> $DIR/send-sync.rs:8:10
    |
 LL |     send(format_args!("{:?}", c));
-   |     ^^^^ `core::fmt::Opaque` cannot be shared between threads safely
+   |     ---- ^^^^^^^^^^^^^^^^^^^^^^^ `core::fmt::Opaque` cannot be shared between threads safely
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: within `[ArgumentV1<'_>]`, the trait `Sync` is not implemented for `core::fmt::Opaque`
    = note: required because it appears within the type `&core::fmt::Opaque`
@@ -17,10 +19,12 @@ LL | fn send<T: Send>(_: T) {}
    |            ^^^^ required by this bound in `send`
 
 error[E0277]: `core::fmt::Opaque` cannot be shared between threads safely
-  --> $DIR/send-sync.rs:9:5
+  --> $DIR/send-sync.rs:9:10
    |
 LL |     sync(format_args!("{:?}", c));
-   |     ^^^^ `core::fmt::Opaque` cannot be shared between threads safely
+   |     ---- ^^^^^^^^^^^^^^^^^^^^^^^ `core::fmt::Opaque` cannot be shared between threads safely
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: within `Arguments<'_>`, the trait `Sync` is not implemented for `core::fmt::Opaque`
    = note: required because it appears within the type `&core::fmt::Opaque`
diff --git a/src/test/ui/generator/drop-tracking-parent-expression.stderr b/src/test/ui/generator/drop-tracking-parent-expression.stderr
index 522a300b3ed79..fbf5d6e07256b 100644
--- a/src/test/ui/generator/drop-tracking-parent-expression.stderr
+++ b/src/test/ui/generator/drop-tracking-parent-expression.stderr
@@ -1,8 +1,8 @@
 error: generator cannot be sent between threads safely
-  --> $DIR/drop-tracking-parent-expression.rs:24:13
+  --> $DIR/drop-tracking-parent-expression.rs:24:25
    |
 LL |               assert_send(g);
-   |               ^^^^^^^^^^^ generator is not `Send`
+   |                           ^ generator is not `Send`
 ...
 LL | /     type_combinations!(
 LL | |         // OK
@@ -41,10 +41,10 @@ LL | fn assert_send<T: Send>(_thing: T) {}
    = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: generator cannot be sent between threads safely
-  --> $DIR/drop-tracking-parent-expression.rs:24:13
+  --> $DIR/drop-tracking-parent-expression.rs:24:25
    |
 LL |               assert_send(g);
-   |               ^^^^^^^^^^^ generator is not `Send`
+   |                           ^ generator is not `Send`
 ...
 LL | /     type_combinations!(
 LL | |         // OK
@@ -83,10 +83,10 @@ LL | fn assert_send<T: Send>(_thing: T) {}
    = note: this error originates in the macro `type_combinations` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: generator cannot be sent between threads safely
-  --> $DIR/drop-tracking-parent-expression.rs:24:13
+  --> $DIR/drop-tracking-parent-expression.rs:24:25
    |
 LL |               assert_send(g);
-   |               ^^^^^^^^^^^ generator is not `Send`
+   |                           ^ generator is not `Send`
 ...
 LL | /     type_combinations!(
 LL | |         // OK
diff --git a/src/test/ui/generator/drop-yield-twice.stderr b/src/test/ui/generator/drop-yield-twice.stderr
index 5bc6ea5600fc5..0808a2c85ee1d 100644
--- a/src/test/ui/generator/drop-yield-twice.stderr
+++ b/src/test/ui/generator/drop-yield-twice.stderr
@@ -1,8 +1,14 @@
 error: generator cannot be sent between threads safely
-  --> $DIR/drop-yield-twice.rs:7:5
+  --> $DIR/drop-yield-twice.rs:7:17
    |
-LL |     assert_send(|| {
-   |     ^^^^^^^^^^^ generator is not `Send`
+LL |       assert_send(|| {
+   |  _________________^
+LL | |         let guard = Foo(42);
+LL | |         yield;
+LL | |         drop(guard);
+LL | |         yield;
+LL | |     })
+   | |_____^ generator is not `Send`
    |
    = help: within `[generator@$DIR/drop-yield-twice.rs:7:17: 7:19]`, the trait `Send` is not implemented for `Foo`
 note: generator is not `Send` as this value is used across a yield
diff --git a/src/test/ui/generator/generator-yielding-or-returning-itself.stderr b/src/test/ui/generator/generator-yielding-or-returning-itself.stderr
index 2a39a08ee39b2..8f5d2429a2892 100644
--- a/src/test/ui/generator/generator-yielding-or-returning-itself.stderr
+++ b/src/test/ui/generator/generator-yielding-or-returning-itself.stderr
@@ -1,8 +1,15 @@
 error[E0271]: type mismatch resolving `<[generator@$DIR/generator-yielding-or-returning-itself.rs:15:34: 15:36] as Generator>::Return == [generator@$DIR/generator-yielding-or-returning-itself.rs:15:34: 15:36]`
-  --> $DIR/generator-yielding-or-returning-itself.rs:15:5
+  --> $DIR/generator-yielding-or-returning-itself.rs:15:34
    |
-LL |     want_cyclic_generator_return(|| {
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cyclic type of infinite size
+LL |       want_cyclic_generator_return(|| {
+   |  _____----------------------------_^
+   | |     |
+   | |     required by a bound introduced by this call
+LL | |
+LL | |         if false { yield None.unwrap(); }
+LL | |         None.unwrap()
+LL | |     })
+   | |_____^ cyclic type of infinite size
    |
    = note: closures cannot capture themselves or take themselves as argument;
            this error may be the result of a recent compiler bug-fix,
@@ -17,10 +24,17 @@ LL |     where T: Generator<Yield = (), Return = T>
    |                                    ^^^^^^^^^^ required by this bound in `want_cyclic_generator_return`
 
 error[E0271]: type mismatch resolving `<[generator@$DIR/generator-yielding-or-returning-itself.rs:28:33: 28:35] as Generator>::Yield == [generator@$DIR/generator-yielding-or-returning-itself.rs:28:33: 28:35]`
-  --> $DIR/generator-yielding-or-returning-itself.rs:28:5
+  --> $DIR/generator-yielding-or-returning-itself.rs:28:33
    |
-LL |     want_cyclic_generator_yield(|| {
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ cyclic type of infinite size
+LL |       want_cyclic_generator_yield(|| {
+   |  _____---------------------------_^
+   | |     |
+   | |     required by a bound introduced by this call
+LL | |
+LL | |         if false { yield None.unwrap(); }
+LL | |         None.unwrap()
+LL | |     })
+   | |_____^ cyclic type of infinite size
    |
    = note: closures cannot capture themselves or take themselves as argument;
            this error may be the result of a recent compiler bug-fix,
diff --git a/src/test/ui/generator/issue-68112.rs b/src/test/ui/generator/issue-68112.rs
index 03b21c5ebd3ee..21026f45cb823 100644
--- a/src/test/ui/generator/issue-68112.rs
+++ b/src/test/ui/generator/issue-68112.rs
@@ -64,6 +64,7 @@ fn test2() {
     //~^ ERROR `RefCell<i32>` cannot be shared between threads safely
     //~| NOTE `RefCell<i32>` cannot be shared between threads safely
     //~| NOTE required for
+    //~| NOTE required by a bound introduced by this call
     //~| NOTE captures the following types
 }
 
diff --git a/src/test/ui/generator/issue-68112.stderr b/src/test/ui/generator/issue-68112.stderr
index b56f445872bc4..eb99d42c92068 100644
--- a/src/test/ui/generator/issue-68112.stderr
+++ b/src/test/ui/generator/issue-68112.stderr
@@ -1,8 +1,8 @@
 error: generator cannot be sent between threads safely
-  --> $DIR/issue-68112.rs:40:5
+  --> $DIR/issue-68112.rs:40:18
    |
 LL |     require_send(send_gen);
-   |     ^^^^^^^^^^^^ generator is not `Send`
+   |                  ^^^^^^^^ generator is not `Send`
    |
    = help: the trait `Sync` is not implemented for `RefCell<i32>`
 note: generator is not `Send` as this value is used across a yield
@@ -23,10 +23,12 @@ LL | fn require_send(_: impl Send) {}
    |                         ^^^^ required by this bound in `require_send`
 
 error[E0277]: `RefCell<i32>` cannot be shared between threads safely
-  --> $DIR/issue-68112.rs:63:5
+  --> $DIR/issue-68112.rs:63:18
    |
 LL |     require_send(send_gen);
-   |     ^^^^^^^^^^^^ `RefCell<i32>` cannot be shared between threads safely
+   |     ------------ ^^^^^^^^ `RefCell<i32>` cannot be shared between threads safely
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: the trait `Sync` is not implemented for `RefCell<i32>`
    = note: required for `Arc<RefCell<i32>>` to implement `Send`
diff --git a/src/test/ui/generator/not-send-sync.stderr b/src/test/ui/generator/not-send-sync.stderr
index b54b0f570c962..a821c57b923a0 100644
--- a/src/test/ui/generator/not-send-sync.stderr
+++ b/src/test/ui/generator/not-send-sync.stderr
@@ -1,8 +1,15 @@
 error[E0277]: `Cell<i32>` cannot be shared between threads safely
-  --> $DIR/not-send-sync.rs:16:5
+  --> $DIR/not-send-sync.rs:16:17
    |
-LL |     assert_send(|| {
-   |     ^^^^^^^^^^^ `Cell<i32>` cannot be shared between threads safely
+LL |       assert_send(|| {
+   |  _____-----------_^
+   | |     |
+   | |     required by a bound introduced by this call
+LL | |
+LL | |         drop(&a);
+LL | |         yield;
+LL | |     });
+   | |_____^ `Cell<i32>` cannot be shared between threads safely
    |
    = help: the trait `Sync` is not implemented for `Cell<i32>`
    = note: required for `&Cell<i32>` to implement `Send`
@@ -18,10 +25,15 @@ LL |     fn assert_send<T: Send>(_: T) {}
    |                       ^^^^ required by this bound in `assert_send`
 
 error: generator cannot be shared between threads safely
-  --> $DIR/not-send-sync.rs:9:5
-   |
-LL |     assert_sync(|| {
-   |     ^^^^^^^^^^^ generator is not `Sync`
+  --> $DIR/not-send-sync.rs:9:17
+   |
+LL |       assert_sync(|| {
+   |  _________________^
+LL | |
+LL | |         let a = Cell::new(2);
+LL | |         yield;
+LL | |     });
+   | |_____^ generator is not `Sync`
    |
    = help: within `[generator@$DIR/not-send-sync.rs:9:17: 9:19]`, the trait `Sync` is not implemented for `Cell<i32>`
 note: generator is not `Sync` as this value is used across a yield
diff --git a/src/test/ui/generator/partial-drop.stderr b/src/test/ui/generator/partial-drop.stderr
index 1004fc64da93a..9baafe54e84d4 100644
--- a/src/test/ui/generator/partial-drop.stderr
+++ b/src/test/ui/generator/partial-drop.stderr
@@ -1,8 +1,15 @@
 error: generator cannot be sent between threads safely
-  --> $DIR/partial-drop.rs:14:5
+  --> $DIR/partial-drop.rs:14:17
    |
-LL |     assert_send(|| {
-   |     ^^^^^^^^^^^ generator is not `Send`
+LL |       assert_send(|| {
+   |  _________________^
+LL | |
+LL | |         // FIXME: it would be nice to make this work.
+LL | |         let guard = Bar { foo: Foo, x: 42 };
+LL | |         drop(guard.foo);
+LL | |         yield;
+LL | |     });
+   | |_____^ generator is not `Send`
    |
    = help: within `[generator@$DIR/partial-drop.rs:14:17: 14:19]`, the trait `Send` is not implemented for `Foo`
 note: generator is not `Send` as this value is used across a yield
@@ -22,10 +29,17 @@ LL | fn assert_send<T: Send>(_: T) {}
    |                   ^^^^ required by this bound in `assert_send`
 
 error: generator cannot be sent between threads safely
-  --> $DIR/partial-drop.rs:22:5
+  --> $DIR/partial-drop.rs:22:17
    |
-LL |     assert_send(|| {
-   |     ^^^^^^^^^^^ generator is not `Send`
+LL |       assert_send(|| {
+   |  _________________^
+LL | |
+LL | |         // FIXME: it would be nice to make this work.
+LL | |         let guard = Bar { foo: Foo, x: 42 };
+...  |
+LL | |         yield;
+LL | |     });
+   | |_____^ generator is not `Send`
    |
    = help: within `[generator@$DIR/partial-drop.rs:22:17: 22:19]`, the trait `Send` is not implemented for `Foo`
 note: generator is not `Send` as this value is used across a yield
@@ -45,10 +59,17 @@ LL | fn assert_send<T: Send>(_: T) {}
    |                   ^^^^ required by this bound in `assert_send`
 
 error: generator cannot be sent between threads safely
-  --> $DIR/partial-drop.rs:32:5
+  --> $DIR/partial-drop.rs:32:17
    |
-LL |     assert_send(|| {
-   |     ^^^^^^^^^^^ generator is not `Send`
+LL |       assert_send(|| {
+   |  _________________^
+LL | |
+LL | |         // FIXME: it would be nice to make this work.
+LL | |         let guard = Bar { foo: Foo, x: 42 };
+...  |
+LL | |         yield;
+LL | |     });
+   | |_____^ generator is not `Send`
    |
    = help: within `[generator@$DIR/partial-drop.rs:32:17: 32:19]`, the trait `Send` is not implemented for `Foo`
 note: generator is not `Send` as this value is used across a yield
diff --git a/src/test/ui/generator/print/generator-print-verbose-1.stderr b/src/test/ui/generator/print/generator-print-verbose-1.stderr
index bbde8ea7892cc..3a83021dd9950 100644
--- a/src/test/ui/generator/print/generator-print-verbose-1.stderr
+++ b/src/test/ui/generator/print/generator-print-verbose-1.stderr
@@ -1,8 +1,8 @@
 error: generator cannot be sent between threads safely
-  --> $DIR/generator-print-verbose-1.rs:37:5
+  --> $DIR/generator-print-verbose-1.rs:37:18
    |
 LL |     require_send(send_gen);
-   |     ^^^^^^^^^^^^ generator is not `Send`
+   |                  ^^^^^^^^ generator is not `Send`
    |
    = help: the trait `Sync` is not implemented for `RefCell<i32>`
 note: generator is not `Send` as this value is used across a yield
@@ -21,10 +21,12 @@ LL | fn require_send(_: impl Send) {}
    |                         ^^^^ required by this bound in `require_send`
 
 error[E0277]: `RefCell<i32>` cannot be shared between threads safely
-  --> $DIR/generator-print-verbose-1.rs:56:5
+  --> $DIR/generator-print-verbose-1.rs:56:18
    |
 LL |     require_send(send_gen);
-   |     ^^^^^^^^^^^^ `RefCell<i32>` cannot be shared between threads safely
+   |     ------------ ^^^^^^^^ `RefCell<i32>` cannot be shared between threads safely
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: the trait `Sync` is not implemented for `RefCell<i32>`
    = note: required for `Arc<RefCell<i32>>` to implement `Send`
diff --git a/src/test/ui/generator/print/generator-print-verbose-2.stderr b/src/test/ui/generator/print/generator-print-verbose-2.stderr
index 92ca51b4e7267..909e49c38b8d1 100644
--- a/src/test/ui/generator/print/generator-print-verbose-2.stderr
+++ b/src/test/ui/generator/print/generator-print-verbose-2.stderr
@@ -1,8 +1,15 @@
 error[E0277]: `Cell<i32>` cannot be shared between threads safely
-  --> $DIR/generator-print-verbose-2.rs:19:5
+  --> $DIR/generator-print-verbose-2.rs:19:17
    |
-LL |     assert_send(|| {
-   |     ^^^^^^^^^^^ `Cell<i32>` cannot be shared between threads safely
+LL |       assert_send(|| {
+   |  _____-----------_^
+   | |     |
+   | |     required by a bound introduced by this call
+LL | |
+LL | |         drop(&a);
+LL | |         yield;
+LL | |     });
+   | |_____^ `Cell<i32>` cannot be shared between threads safely
    |
    = help: the trait `Sync` is not implemented for `Cell<i32>`
    = note: required for `&'_#4r Cell<i32>` to implement `Send`
@@ -18,10 +25,15 @@ LL |     fn assert_send<T: Send>(_: T) {}
    |                       ^^^^ required by this bound in `assert_send`
 
 error: generator cannot be shared between threads safely
-  --> $DIR/generator-print-verbose-2.rs:12:5
-   |
-LL |     assert_sync(|| {
-   |     ^^^^^^^^^^^ generator is not `Sync`
+  --> $DIR/generator-print-verbose-2.rs:12:17
+   |
+LL |       assert_sync(|| {
+   |  _________________^
+LL | |
+LL | |         let a = Cell::new(2);
+LL | |         yield;
+LL | |     });
+   | |_____^ generator is not `Sync`
    |
    = help: within `[main::{closure#0} upvar_tys=() {Cell<i32>, ()}]`, the trait `Sync` is not implemented for `Cell<i32>`
 note: generator is not `Sync` as this value is used across a yield
diff --git a/src/test/ui/generic-associated-types/bugs/issue-88460.stderr b/src/test/ui/generic-associated-types/bugs/issue-88460.stderr
index 98c304cc90b53..8193f491e69ed 100644
--- a/src/test/ui/generic-associated-types/bugs/issue-88460.stderr
+++ b/src/test/ui/generic-associated-types/bugs/issue-88460.stderr
@@ -1,8 +1,10 @@
 error[E0277]: the trait bound `for<'a> <_ as Trait>::Assoc<'a>: Marker` is not satisfied
-  --> $DIR/issue-88460.rs:30:5
+  --> $DIR/issue-88460.rs:30:10
    |
 LL |     test(Foo);
-   |     ^^^^ the trait `for<'a> Marker` is not implemented for `<_ as Trait>::Assoc<'a>`
+   |     ---- ^^^ the trait `for<'a> Marker` is not implemented for `<_ as Trait>::Assoc<'a>`
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: the trait `Marker` is implemented for `()`
 note: required by a bound in `test`
diff --git a/src/test/ui/higher-rank-trait-bounds/normalize-under-binder/issue-62529-3.stderr b/src/test/ui/higher-rank-trait-bounds/normalize-under-binder/issue-62529-3.stderr
index 066bf431a83d7..b30dd36d2ad6a 100644
--- a/src/test/ui/higher-rank-trait-bounds/normalize-under-binder/issue-62529-3.stderr
+++ b/src/test/ui/higher-rank-trait-bounds/normalize-under-binder/issue-62529-3.stderr
@@ -1,8 +1,10 @@
 error[E0277]: expected a `Fn<(<_ as ATC<'a>>::Type,)>` closure, found `F`
-  --> $DIR/issue-62529-3.rs:25:9
+  --> $DIR/issue-62529-3.rs:25:14
    |
 LL |         call(f, ());
-   |         ^^^^ expected an `Fn<(<_ as ATC<'a>>::Type,)>` closure, found `F`
+   |         ---- ^ expected an `Fn<(<_ as ATC<'a>>::Type,)>` closure, found `F`
+   |         |
+   |         required by a bound introduced by this call
    |
    = note: expected a closure with arguments `((),)`
               found a closure with arguments `(<_ as ATC<'a>>::Type,)`
diff --git a/src/test/ui/inference/issue-71732.stderr b/src/test/ui/inference/issue-71732.stderr
index 04673a375cf01..79bee33280d2e 100644
--- a/src/test/ui/inference/issue-71732.stderr
+++ b/src/test/ui/inference/issue-71732.stderr
@@ -2,7 +2,9 @@ error[E0283]: type annotations needed
   --> $DIR/issue-71732.rs:18:10
    |
 LL |         .get(&"key".into())
-   |          ^^^ cannot infer type of the type parameter `Q` declared on the associated function `get`
+   |          ^^^ ------------- type must be known at this point
+   |          |
+   |          cannot infer type of the type parameter `Q` declared on the associated function `get`
    |
    = note: multiple `impl`s satisfying `String: Borrow<_>` found in the following crates: `alloc`, `core`:
            - impl Borrow<str> for String;
@@ -13,7 +15,7 @@ note: required by a bound in `HashMap::<K, V, S>::get`
    |
 LL |         K: Borrow<Q>,
    |            ^^^^^^^^^ required by this bound in `HashMap::<K, V, S>::get`
-help: consider specifying the type argument in the function call
+help: consider specifying the generic argument
    |
 LL |         .get::<Q>(&"key".into())
    |             +++++
diff --git a/src/test/ui/inference/issue-86162-1.stderr b/src/test/ui/inference/issue-86162-1.stderr
index e395e65fad066..4f621b82dc579 100644
--- a/src/test/ui/inference/issue-86162-1.stderr
+++ b/src/test/ui/inference/issue-86162-1.stderr
@@ -4,7 +4,7 @@ error[E0283]: type annotations needed
 LL |     foo(gen()); //<- Do not suggest `foo::<impl Clone>()`!
    |     --- ^^^ cannot infer type of the type parameter `T` declared on the function `gen`
    |     |
-   |     type must be known at this point
+   |     required by a bound introduced by this call
    |
    = note: cannot satisfy `_: Clone`
 note: required by a bound in `foo`
diff --git a/src/test/ui/inference/issue-86162-2.stderr b/src/test/ui/inference/issue-86162-2.stderr
index 30e6e10eaa2fd..9aff2cec160f2 100644
--- a/src/test/ui/inference/issue-86162-2.stderr
+++ b/src/test/ui/inference/issue-86162-2.stderr
@@ -4,7 +4,7 @@ error[E0283]: type annotations needed
 LL |     Foo::bar(gen()); //<- Do not suggest `Foo::bar::<impl Clone>()`!
    |     -------- ^^^ cannot infer type of the type parameter `T` declared on the function `gen`
    |     |
-   |     type must be known at this point
+   |     required by a bound introduced by this call
    |
    = note: cannot satisfy `_: Clone`
 note: required by a bound in `Foo::bar`
diff --git a/src/test/ui/interior-mutability/interior-mutability.stderr b/src/test/ui/interior-mutability/interior-mutability.stderr
index 7955fecda0670..94f41c9259886 100644
--- a/src/test/ui/interior-mutability/interior-mutability.stderr
+++ b/src/test/ui/interior-mutability/interior-mutability.stderr
@@ -1,8 +1,10 @@
 error[E0277]: the type `UnsafeCell<i32>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
-  --> $DIR/interior-mutability.rs:5:5
+  --> $DIR/interior-mutability.rs:5:18
    |
 LL |     catch_unwind(|| { x.set(23); });
-   |     ^^^^^^^^^^^^ `UnsafeCell<i32>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
+   |     ------------ ^^^^^^^^^^^^^^^^^ `UnsafeCell<i32>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: within `Cell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<i32>`
    = note: required because it appears within the type `Cell<i32>`
diff --git a/src/test/ui/issues/issue-20162.stderr b/src/test/ui/issues/issue-20162.stderr
index d70bf6e1d921c..3f9b3be985179 100644
--- a/src/test/ui/issues/issue-20162.stderr
+++ b/src/test/ui/issues/issue-20162.stderr
@@ -1,8 +1,10 @@
 error[E0277]: the trait bound `X: Ord` is not satisfied
-  --> $DIR/issue-20162.rs:5:7
+  --> $DIR/issue-20162.rs:5:5
    |
 LL |     b.sort();
-   |       ^^^^ the trait `Ord` is not implemented for `X`
+   |     ^ ---- required by a bound introduced by this call
+   |     |
+   |     the trait `Ord` is not implemented for `X`
    |
 note: required by a bound in `slice::<impl [T]>::sort`
   --> $SRC_DIR/alloc/src/slice.rs:LL:COL
diff --git a/src/test/ui/issues/issue-20605.stderr b/src/test/ui/issues/issue-20605.stderr
index b41b602a55b5c..e1858b6398932 100644
--- a/src/test/ui/issues/issue-20605.stderr
+++ b/src/test/ui/issues/issue-20605.stderr
@@ -2,7 +2,7 @@ error[E0277]: the size for values of type `dyn Iterator<Item = &'a mut u8>` cann
   --> $DIR/issue-20605.rs:2:17
    |
 LL |     for item in *things { *item = 0 }
-   |                 ^^^^^^^ expected an implementor of trait `IntoIterator`
+   |                 ^^^^^^^ the trait `IntoIterator` is not implemented for `dyn Iterator<Item = &'a mut u8>`
    |
    = note: the trait bound `dyn Iterator<Item = &'a mut u8>: IntoIterator` is not satisfied
    = note: required for `dyn Iterator<Item = &'a mut u8>` to implement `IntoIterator`
diff --git a/src/test/ui/issues/issue-21763.stderr b/src/test/ui/issues/issue-21763.stderr
index 790681589248a..72c65029746ad 100644
--- a/src/test/ui/issues/issue-21763.stderr
+++ b/src/test/ui/issues/issue-21763.stderr
@@ -1,8 +1,8 @@
 error[E0277]: `Rc<()>` cannot be sent between threads safely
-  --> $DIR/issue-21763.rs:9:5
+  --> $DIR/issue-21763.rs:9:11
    |
 LL |     foo::<HashMap<Rc<()>, Rc<()>>>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `Rc<()>` cannot be sent between threads safely
+   |           ^^^^^^^^^^^^^^^^^^^^^^^ `Rc<()>` cannot be sent between threads safely
    |
    = help: within `(Rc<()>, Rc<()>)`, the trait `Send` is not implemented for `Rc<()>`
    = note: required because it appears within the type `(Rc<()>, Rc<()>)`
diff --git a/src/test/ui/issues/issue-31173.rs b/src/test/ui/issues/issue-31173.rs
index 472a95d4636bc..04efa27189b74 100644
--- a/src/test/ui/issues/issue-31173.rs
+++ b/src/test/ui/issues/issue-31173.rs
@@ -4,12 +4,12 @@ pub fn get_tok(it: &mut IntoIter<u8>) {
     let mut found_e = false;
 
     let temp: Vec<u8> = it
+        //~^ ERROR to be an iterator that yields `&_`, but it yields `u8`
         .take_while(|&x| {
             found_e = true;
             false
         })
         .cloned()
-        //~^ ERROR to be an iterator that yields `&_`, but it yields `u8`
         .collect(); //~ ERROR the method
 }
 
diff --git a/src/test/ui/issues/issue-31173.stderr b/src/test/ui/issues/issue-31173.stderr
index 0b8222088b879..e3334eef3ad7f 100644
--- a/src/test/ui/issues/issue-31173.stderr
+++ b/src/test/ui/issues/issue-31173.stderr
@@ -1,8 +1,16 @@
-error[E0271]: expected `TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:7:21: 7:25]>` to be an iterator that yields `&_`, but it yields `u8`
-  --> $DIR/issue-31173.rs:11:10
-   |
-LL |         .cloned()
-   |          ^^^^^^ expected reference, found `u8`
+error[E0271]: expected `TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:8:21: 8:25]>` to be an iterator that yields `&_`, but it yields `u8`
+  --> $DIR/issue-31173.rs:6:25
+   |
+LL |       let temp: Vec<u8> = it
+   |  _________________________^
+LL | |
+LL | |         .take_while(|&x| {
+LL | |             found_e = true;
+LL | |             false
+LL | |         })
+   | |__________^ expected reference, found `u8`
+LL |           .cloned()
+   |            ------ required by a bound introduced by this call
    |
    = note: expected reference `&_`
                    found type `u8`
@@ -12,11 +20,11 @@ note: required by a bound in `cloned`
 LL |         Self: Sized + Iterator<Item = &'a T>,
    |                                ^^^^^^^^^^^^ required by this bound in `cloned`
 
-error[E0599]: the method `collect` exists for struct `Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:7:21: 7:25]>>`, but its trait bounds were not satisfied
+error[E0599]: the method `collect` exists for struct `Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:8:21: 8:25]>>`, but its trait bounds were not satisfied
   --> $DIR/issue-31173.rs:13:10
    |
 LL |         .collect();
-   |          ^^^^^^^ method cannot be called on `Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:7:21: 7:25]>>` due to unsatisfied trait bounds
+   |          ^^^^^^^ method cannot be called on `Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:8:21: 8:25]>>` due to unsatisfied trait bounds
    |
   ::: $SRC_DIR/core/src/iter/adapters/take_while.rs:LL:COL
    |
@@ -29,10 +37,10 @@ LL | pub struct Cloned<I> {
    | -------------------- doesn't satisfy `_: Iterator`
    |
    = note: the following trait bounds were not satisfied:
-           `<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:7:21: 7:25]> as Iterator>::Item = &_`
-           which is required by `Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:7:21: 7:25]>>: Iterator`
-           `Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:7:21: 7:25]>>: Iterator`
-           which is required by `&mut Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:7:21: 7:25]>>: Iterator`
+           `<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:8:21: 8:25]> as Iterator>::Item = &_`
+           which is required by `Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:8:21: 8:25]>>: Iterator`
+           `Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:8:21: 8:25]>>: Iterator`
+           which is required by `&mut Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:8:21: 8:25]>>: Iterator`
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/issues/issue-33941.stderr b/src/test/ui/issues/issue-33941.stderr
index caba0ad52689e..691b8f88f4ed5 100644
--- a/src/test/ui/issues/issue-33941.stderr
+++ b/src/test/ui/issues/issue-33941.stderr
@@ -1,8 +1,10 @@
 error[E0271]: expected `std::collections::hash_map::Iter<'_, _, _>` to be an iterator that yields `&_`, but it yields `(&_, &_)`
-  --> $DIR/issue-33941.rs:6:36
+  --> $DIR/issue-33941.rs:6:14
    |
 LL |     for _ in HashMap::new().iter().cloned() {}
-   |                                    ^^^^^^ expected reference, found tuple
+   |              ^^^^^^^^^^^^^^^^^^^^^ ------ required by a bound introduced by this call
+   |              |
+   |              expected reference, found tuple
    |
    = note: expected reference `&_`
                   found tuple `(&_, &_)`
diff --git a/src/test/ui/issues/issue-34334.stderr b/src/test/ui/issues/issue-34334.stderr
index 48ae2df691c3d..72082f0cd1728 100644
--- a/src/test/ui/issues/issue-34334.stderr
+++ b/src/test/ui/issues/issue-34334.stderr
@@ -13,10 +13,12 @@ LL |     let sr: Vec<(u32, _, _)> = vec![];
    |                            +
 
 error[E0277]: a value of type `Vec<(u32, _, _)>` cannot be built from an iterator over elements of type `()`
-  --> $DIR/issue-34334.rs:5:87
+  --> $DIR/issue-34334.rs:5:33
    |
 LL |     let sr2: Vec<(u32, _, _)> = sr.iter().map(|(faction, th_sender, th_receiver)| {}).collect();
-   |                                                                                       ^^^^^^^ value of type `Vec<(u32, _, _)>` cannot be built from `std::iter::Iterator<Item=()>`
+   |                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ------- required by a bound introduced by this call
+   |                                 |
+   |                                 value of type `Vec<(u32, _, _)>` cannot be built from `std::iter::Iterator<Item=()>`
    |
    = help: the trait `FromIterator<()>` is not implemented for `Vec<(u32, _, _)>`
    = help: the trait `FromIterator<T>` is implemented for `Vec<T>`
diff --git a/src/test/ui/issues/issue-34349.stderr b/src/test/ui/issues/issue-34349.stderr
index d0b51961b44a7..8e9a16619f3b1 100644
--- a/src/test/ui/issues/issue-34349.stderr
+++ b/src/test/ui/issues/issue-34349.stderr
@@ -7,7 +7,15 @@ LL |         farewell.push_str("!!!");
    |         -------- closure is `FnMut` because it mutates the variable `farewell` here
 ...
 LL |     apply(diary);
-   |     ----- the requirement to implement `Fn` derives from here
+   |     ----- ----- the requirement to implement `Fn` derives from here
+   |     |
+   |     required by a bound introduced by this call
+   |
+note: required by a bound in `apply`
+  --> $DIR/issue-34349.rs:11:32
+   |
+LL |     fn apply<F>(f: F) where F: Fn() {
+   |                                ^^^^ required by this bound in `apply`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-59488.rs b/src/test/ui/issues/issue-59488.rs
index 922b593935aa8..384501e3e5dfd 100644
--- a/src/test/ui/issues/issue-59488.rs
+++ b/src/test/ui/issues/issue-59488.rs
@@ -30,4 +30,5 @@ fn main() {
     assert_eq!(Foo::Bar, i);
     //~^ ERROR binary operation `==` cannot be applied to type `fn(usize) -> Foo {Foo::Bar}` [E0369]
     //~| ERROR `fn(usize) -> Foo {Foo::Bar}` doesn't implement `Debug` [E0277]
+    //~| ERROR `fn(usize) -> Foo {Foo::Bar}` doesn't implement `Debug` [E0277]
 }
diff --git a/src/test/ui/issues/issue-59488.stderr b/src/test/ui/issues/issue-59488.stderr
index 7ce3dedaa887b..bb6843a19586e 100644
--- a/src/test/ui/issues/issue-59488.stderr
+++ b/src/test/ui/issues/issue-59488.stderr
@@ -106,7 +106,26 @@ LL |     assert_eq!(Foo::Bar, i);
            and 68 others
    = note: this error originates in the macro `assert_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: aborting due to 9 previous errors
+error[E0277]: `fn(usize) -> Foo {Foo::Bar}` doesn't implement `Debug`
+  --> $DIR/issue-59488.rs:30:5
+   |
+LL |     assert_eq!(Foo::Bar, i);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^ `fn(usize) -> Foo {Foo::Bar}` cannot be formatted using `{:?}` because it doesn't implement `Debug`
+   |
+   = help: the trait `Debug` is not implemented for `fn(usize) -> Foo {Foo::Bar}`
+   = help: the following other types implement trait `Debug`:
+             extern "C" fn() -> Ret
+             extern "C" fn(A, B) -> Ret
+             extern "C" fn(A, B, ...) -> Ret
+             extern "C" fn(A, B, C) -> Ret
+             extern "C" fn(A, B, C, ...) -> Ret
+             extern "C" fn(A, B, C, D) -> Ret
+             extern "C" fn(A, B, C, D, ...) -> Ret
+             extern "C" fn(A, B, C, D, E) -> Ret
+           and 68 others
+   = note: this error originates in the macro `assert_eq` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 10 previous errors
 
 Some errors have detailed explanations: E0277, E0308, E0369.
 For more information about an error, try `rustc --explain E0277`.
diff --git a/src/test/ui/issues/issue-60218.stderr b/src/test/ui/issues/issue-60218.stderr
index 870b25014471d..dd72b6515ddca 100644
--- a/src/test/ui/issues/issue-60218.stderr
+++ b/src/test/ui/issues/issue-60218.stderr
@@ -1,8 +1,8 @@
 error[E0277]: the trait bound `&u32: Foo` is not satisfied
-  --> $DIR/issue-60218.rs:18:27
+  --> $DIR/issue-60218.rs:18:19
    |
 LL |     trigger_error(vec![], |x: &u32| x)
-   |     -------------         ^^^^^^^^^^^ the trait `Foo` is not implemented for `&u32`
+   |     ------------- ^^^^^^ the trait `Foo` is not implemented for `&u32`
    |     |
    |     required by a bound introduced by this call
    |
diff --git a/src/test/ui/issues/issue-66923-show-error-for-correct-call.stderr b/src/test/ui/issues/issue-66923-show-error-for-correct-call.stderr
index d6e39251632ba..2de1503765082 100644
--- a/src/test/ui/issues/issue-66923-show-error-for-correct-call.stderr
+++ b/src/test/ui/issues/issue-66923-show-error-for-correct-call.stderr
@@ -1,8 +1,10 @@
 error[E0277]: a value of type `Vec<f64>` cannot be built from an iterator over elements of type `&f64`
-  --> $DIR/issue-66923-show-error-for-correct-call.rs:8:39
+  --> $DIR/issue-66923-show-error-for-correct-call.rs:8:24
    |
 LL |     let x2: Vec<f64> = x1.into_iter().collect();
-   |                                       ^^^^^^^ value of type `Vec<f64>` cannot be built from `std::iter::Iterator<Item=&f64>`
+   |                        ^^^^^^^^^^^^^^ ------- required by a bound introduced by this call
+   |                        |
+   |                        value of type `Vec<f64>` cannot be built from `std::iter::Iterator<Item=&f64>`
    |
    = help: the trait `FromIterator<&f64>` is not implemented for `Vec<f64>`
    = help: the trait `FromIterator<T>` is implemented for `Vec<T>`
@@ -13,10 +15,12 @@ LL |     fn collect<B: FromIterator<Self::Item>>(self) -> B
    |                   ^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `collect`
 
 error[E0277]: a value of type `Vec<f64>` cannot be built from an iterator over elements of type `&f64`
-  --> $DIR/issue-66923-show-error-for-correct-call.rs:12:29
+  --> $DIR/issue-66923-show-error-for-correct-call.rs:12:14
    |
 LL |     let x3 = x1.into_iter().collect::<Vec<f64>>();
-   |                             ^^^^^^^ value of type `Vec<f64>` cannot be built from `std::iter::Iterator<Item=&f64>`
+   |              ^^^^^^^^^^^^^^ ------- required by a bound introduced by this call
+   |              |
+   |              value of type `Vec<f64>` cannot be built from `std::iter::Iterator<Item=&f64>`
    |
    = help: the trait `FromIterator<&f64>` is not implemented for `Vec<f64>`
    = help: the trait `FromIterator<T>` is implemented for `Vec<T>`
diff --git a/src/test/ui/issues/issue-69455.stderr b/src/test/ui/issues/issue-69455.stderr
index b732df764e57f..9d11cf19ea77c 100644
--- a/src/test/ui/issues/issue-69455.stderr
+++ b/src/test/ui/issues/issue-69455.stderr
@@ -16,7 +16,7 @@ error[E0283]: type annotations needed
 LL |     println!("{}", 23u64.test(xs.iter().sum()));
    |                          ----           ^^^ cannot infer type of the type parameter `S` declared on the associated function `sum`
    |                          |
-   |                          type must be known at this point
+   |                          required by a bound introduced by this call
    |
 note: multiple `impl`s satisfying `u64: Test<_>` found
   --> $DIR/issue-69455.rs:11:1
diff --git a/src/test/ui/iterators/collect-into-array.rs b/src/test/ui/iterators/collect-into-array.rs
index a1144c8cb8c6a..7d35da825328e 100644
--- a/src/test/ui/iterators/collect-into-array.rs
+++ b/src/test/ui/iterators/collect-into-array.rs
@@ -4,4 +4,5 @@ fn main() {
     //~^ ERROR an array of type `[u32; 10]` cannot be built directly from an iterator
     //~| NOTE try collecting into a `Vec<{integer}>`, then using `.try_into()`
     //~| NOTE required by a bound in `collect`
+    //~| NOTE required by a bound introduced by this call
 }
diff --git a/src/test/ui/iterators/collect-into-array.stderr b/src/test/ui/iterators/collect-into-array.stderr
index 7be53a4873bcc..7fe9707e6d232 100644
--- a/src/test/ui/iterators/collect-into-array.stderr
+++ b/src/test/ui/iterators/collect-into-array.stderr
@@ -1,8 +1,10 @@
 error[E0277]: an array of type `[u32; 10]` cannot be built directly from an iterator
-  --> $DIR/collect-into-array.rs:3:39
+  --> $DIR/collect-into-array.rs:3:31
    |
 LL |     let whatever: [u32; 10] = (0..10).collect();
-   |                                       ^^^^^^^ try collecting into a `Vec<{integer}>`, then using `.try_into()`
+   |                               ^^^^^^^ ------- required by a bound introduced by this call
+   |                               |
+   |                               try collecting into a `Vec<{integer}>`, then using `.try_into()`
    |
    = help: the trait `FromIterator<{integer}>` is not implemented for `[u32; 10]`
 note: required by a bound in `collect`
diff --git a/src/test/ui/iterators/collect-into-slice.rs b/src/test/ui/iterators/collect-into-slice.rs
index aafa6bc8b9514..5eade075613fe 100644
--- a/src/test/ui/iterators/collect-into-slice.rs
+++ b/src/test/ui/iterators/collect-into-slice.rs
@@ -1,15 +1,20 @@
 fn process_slice(data: &[i32]) {
     //~^ NOTE required by a bound in this
+    //~| NOTE required by a bound in this
     todo!()
 }
 
 fn main() {
     let some_generated_vec = (0..10).collect();
     //~^ ERROR the size for values of type `[i32]` cannot be known at compilation time
+    //~| ERROR the size for values of type `[i32]` cannot be known at compilation time
     //~| ERROR a slice of type `[i32]` cannot be built since `[i32]` has no definite size
     //~| NOTE try explicitly collecting into a `Vec<{integer}>`
     //~| NOTE required by a bound in `collect`
+    //~| NOTE required by a bound in `collect`
     //~| NOTE all local variables must have a statically known size
     //~| NOTE doesn't have a size known at compile-time
+    //~| NOTE doesn't have a size known at compile-time
+    //~| NOTE required by a bound introduced by this call
     process_slice(&some_generated_vec);
 }
diff --git a/src/test/ui/iterators/collect-into-slice.stderr b/src/test/ui/iterators/collect-into-slice.stderr
index 4842e65fe976b..bce40118bdfa0 100644
--- a/src/test/ui/iterators/collect-into-slice.stderr
+++ b/src/test/ui/iterators/collect-into-slice.stderr
@@ -1,5 +1,5 @@
 error[E0277]: the size for values of type `[i32]` cannot be known at compilation time
-  --> $DIR/collect-into-slice.rs:7:9
+  --> $DIR/collect-into-slice.rs:8:9
    |
 LL |     let some_generated_vec = (0..10).collect();
    |         ^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
@@ -8,11 +8,26 @@ LL |     let some_generated_vec = (0..10).collect();
    = note: all local variables must have a statically known size
    = help: unsized locals are gated as an unstable feature
 
+error[E0277]: the size for values of type `[i32]` cannot be known at compilation time
+  --> $DIR/collect-into-slice.rs:8:38
+   |
+LL |     let some_generated_vec = (0..10).collect();
+   |                                      ^^^^^^^ doesn't have a size known at compile-time
+   |
+   = help: the trait `Sized` is not implemented for `[i32]`
+note: required by a bound in `collect`
+  --> $SRC_DIR/core/src/iter/traits/iterator.rs:LL:COL
+   |
+LL |     fn collect<B: FromIterator<Self::Item>>(self) -> B
+   |                ^ required by this bound in `collect`
+
 error[E0277]: a slice of type `[i32]` cannot be built since `[i32]` has no definite size
-  --> $DIR/collect-into-slice.rs:7:38
+  --> $DIR/collect-into-slice.rs:8:30
    |
 LL |     let some_generated_vec = (0..10).collect();
-   |                                      ^^^^^^^ try explicitly collecting into a `Vec<{integer}>`
+   |                              ^^^^^^^ ------- required by a bound introduced by this call
+   |                              |
+   |                              try explicitly collecting into a `Vec<{integer}>`
    |
    = help: the trait `FromIterator<{integer}>` is not implemented for `[i32]`
 note: required by a bound in `collect`
@@ -21,6 +36,6 @@ note: required by a bound in `collect`
 LL |     fn collect<B: FromIterator<Self::Item>>(self) -> B
    |                   ^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `collect`
 
-error: aborting due to 2 previous errors
+error: aborting due to 3 previous errors
 
 For more information about this error, try `rustc --explain E0277`.
diff --git a/src/test/ui/kindck/kindck-impl-type-params-2.rs b/src/test/ui/kindck/kindck-impl-type-params-2.rs
index 8b0771985dc3f..8950fc51e643c 100644
--- a/src/test/ui/kindck/kindck-impl-type-params-2.rs
+++ b/src/test/ui/kindck/kindck-impl-type-params-2.rs
@@ -11,5 +11,5 @@ fn take_param<T:Foo>(foo: &T) { }
 fn main() {
     let x: Box<_> = Box::new(3);
     take_param(&x);
-    //~^ ERROR the trait bound `Box<{integer}>: Foo` is not satisfied
+    //~^ ERROR the trait bound `Box<{integer}>: Copy` is not satisfied
 }
diff --git a/src/test/ui/kindck/kindck-impl-type-params-2.stderr b/src/test/ui/kindck/kindck-impl-type-params-2.stderr
index 06d48ff1f0f27..930d96375bff4 100644
--- a/src/test/ui/kindck/kindck-impl-type-params-2.stderr
+++ b/src/test/ui/kindck/kindck-impl-type-params-2.stderr
@@ -1,4 +1,4 @@
-error[E0277]: the trait bound `Box<{integer}>: Foo` is not satisfied
+error[E0277]: the trait bound `Box<{integer}>: Copy` is not satisfied
   --> $DIR/kindck-impl-type-params-2.rs:13:16
    |
 LL |     take_param(&x);
diff --git a/src/test/ui/kindck/kindck-inherited-copy-bound.curr.stderr b/src/test/ui/kindck/kindck-inherited-copy-bound.curr.stderr
index 09661289a9b77..e81d2441e6ef8 100644
--- a/src/test/ui/kindck/kindck-inherited-copy-bound.curr.stderr
+++ b/src/test/ui/kindck/kindck-inherited-copy-bound.curr.stderr
@@ -1,4 +1,4 @@
-error[E0277]: the trait bound `Box<{integer}>: Foo` is not satisfied
+error[E0277]: the trait bound `Box<{integer}>: Copy` is not satisfied
   --> $DIR/kindck-inherited-copy-bound.rs:21:16
    |
 LL |     take_param(&x);
diff --git a/src/test/ui/kindck/kindck-inherited-copy-bound.object_safe_for_dispatch.stderr b/src/test/ui/kindck/kindck-inherited-copy-bound.object_safe_for_dispatch.stderr
index 299600eb6bf30..2380533b9c3ef 100644
--- a/src/test/ui/kindck/kindck-inherited-copy-bound.object_safe_for_dispatch.stderr
+++ b/src/test/ui/kindck/kindck-inherited-copy-bound.object_safe_for_dispatch.stderr
@@ -1,4 +1,4 @@
-error[E0277]: the trait bound `Box<{integer}>: Foo` is not satisfied
+error[E0277]: the trait bound `Box<{integer}>: Copy` is not satisfied
   --> $DIR/kindck-inherited-copy-bound.rs:21:16
    |
 LL |     take_param(&x);
diff --git a/src/test/ui/kindck/kindck-nonsendable-1.stderr b/src/test/ui/kindck/kindck-nonsendable-1.stderr
index eab003a110782..cc6e1f59c7789 100644
--- a/src/test/ui/kindck/kindck-nonsendable-1.stderr
+++ b/src/test/ui/kindck/kindck-nonsendable-1.stderr
@@ -1,10 +1,12 @@
 error[E0277]: `Rc<usize>` cannot be sent between threads safely
-  --> $DIR/kindck-nonsendable-1.rs:9:5
+  --> $DIR/kindck-nonsendable-1.rs:9:9
    |
 LL |     bar(move|| foo(x));
-   |     ^^^ ------ within this `[closure@$DIR/kindck-nonsendable-1.rs:9:9: 9:15]`
-   |     |
-   |     `Rc<usize>` cannot be sent between threads safely
+   |     --- ------^^^^^^^
+   |     |   |
+   |     |   `Rc<usize>` cannot be sent between threads safely
+   |     |   within this `[closure@$DIR/kindck-nonsendable-1.rs:9:9: 9:15]`
+   |     required by a bound introduced by this call
    |
    = help: within `[closure@$DIR/kindck-nonsendable-1.rs:9:9: 9:15]`, the trait `Send` is not implemented for `Rc<usize>`
 note: required because it's used within this closure
diff --git a/src/test/ui/kindck/kindck-send-object.stderr b/src/test/ui/kindck/kindck-send-object.stderr
index 47b7462a6a104..e9bbeeacd7013 100644
--- a/src/test/ui/kindck/kindck-send-object.stderr
+++ b/src/test/ui/kindck/kindck-send-object.stderr
@@ -1,8 +1,8 @@
 error[E0277]: `(dyn Dummy + 'static)` cannot be shared between threads safely
-  --> $DIR/kindck-send-object.rs:12:5
+  --> $DIR/kindck-send-object.rs:12:19
    |
 LL |     assert_send::<&'static (dyn Dummy + 'static)>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `(dyn Dummy + 'static)` cannot be shared between threads safely
+   |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `(dyn Dummy + 'static)` cannot be shared between threads safely
    |
    = help: the trait `Sync` is not implemented for `(dyn Dummy + 'static)`
    = note: required for `&'static (dyn Dummy + 'static)` to implement `Send`
@@ -13,10 +13,10 @@ LL | fn assert_send<T:Send>() { }
    |                  ^^^^ required by this bound in `assert_send`
 
 error[E0277]: `dyn Dummy` cannot be sent between threads safely
-  --> $DIR/kindck-send-object.rs:17:5
+  --> $DIR/kindck-send-object.rs:17:19
    |
 LL |     assert_send::<Box<dyn Dummy>>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `dyn Dummy` cannot be sent between threads safely
+   |                   ^^^^^^^^^^^^^^ `dyn Dummy` cannot be sent between threads safely
    |
    = help: the trait `Send` is not implemented for `dyn Dummy`
    = note: required for `Unique<dyn Dummy>` to implement `Send`
diff --git a/src/test/ui/kindck/kindck-send-object1.stderr b/src/test/ui/kindck/kindck-send-object1.stderr
index 24428266cc717..11f597fee91be 100644
--- a/src/test/ui/kindck/kindck-send-object1.stderr
+++ b/src/test/ui/kindck/kindck-send-object1.stderr
@@ -1,8 +1,8 @@
 error[E0277]: `(dyn Dummy + 'a)` cannot be shared between threads safely
-  --> $DIR/kindck-send-object1.rs:10:5
+  --> $DIR/kindck-send-object1.rs:10:19
    |
 LL |     assert_send::<&'a dyn Dummy>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `(dyn Dummy + 'a)` cannot be shared between threads safely
+   |                   ^^^^^^^^^^^^^ `(dyn Dummy + 'a)` cannot be shared between threads safely
    |
    = help: the trait `Sync` is not implemented for `(dyn Dummy + 'a)`
    = note: required for `&'a (dyn Dummy + 'a)` to implement `Send`
@@ -13,10 +13,10 @@ LL | fn assert_send<T:Send+'static>() { }
    |                  ^^^^ required by this bound in `assert_send`
 
 error[E0277]: `(dyn Dummy + 'a)` cannot be sent between threads safely
-  --> $DIR/kindck-send-object1.rs:28:5
+  --> $DIR/kindck-send-object1.rs:28:19
    |
 LL |     assert_send::<Box<dyn Dummy + 'a>>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `(dyn Dummy + 'a)` cannot be sent between threads safely
+   |                   ^^^^^^^^^^^^^^^^^^^ `(dyn Dummy + 'a)` cannot be sent between threads safely
    |
    = help: the trait `Send` is not implemented for `(dyn Dummy + 'a)`
    = note: required for `Unique<(dyn Dummy + 'a)>` to implement `Send`
diff --git a/src/test/ui/kindck/kindck-send-object2.stderr b/src/test/ui/kindck/kindck-send-object2.stderr
index 81ec65950d875..b8af33d0dc120 100644
--- a/src/test/ui/kindck/kindck-send-object2.stderr
+++ b/src/test/ui/kindck/kindck-send-object2.stderr
@@ -1,8 +1,8 @@
 error[E0277]: `(dyn Dummy + 'static)` cannot be shared between threads safely
-  --> $DIR/kindck-send-object2.rs:7:5
+  --> $DIR/kindck-send-object2.rs:7:19
    |
 LL |     assert_send::<&'static dyn Dummy>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `(dyn Dummy + 'static)` cannot be shared between threads safely
+   |                   ^^^^^^^^^^^^^^^^^^ `(dyn Dummy + 'static)` cannot be shared between threads safely
    |
    = help: the trait `Sync` is not implemented for `(dyn Dummy + 'static)`
    = note: required for `&'static (dyn Dummy + 'static)` to implement `Send`
@@ -13,10 +13,10 @@ LL | fn assert_send<T:Send>() { }
    |                  ^^^^ required by this bound in `assert_send`
 
 error[E0277]: `dyn Dummy` cannot be sent between threads safely
-  --> $DIR/kindck-send-object2.rs:12:5
+  --> $DIR/kindck-send-object2.rs:12:19
    |
 LL |     assert_send::<Box<dyn Dummy>>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `dyn Dummy` cannot be sent between threads safely
+   |                   ^^^^^^^^^^^^^^ `dyn Dummy` cannot be sent between threads safely
    |
    = help: the trait `Send` is not implemented for `dyn Dummy`
    = note: required for `Unique<dyn Dummy>` to implement `Send`
diff --git a/src/test/ui/kindck/kindck-send-owned.stderr b/src/test/ui/kindck/kindck-send-owned.stderr
index 076c42959826d..b03f56465cea0 100644
--- a/src/test/ui/kindck/kindck-send-owned.stderr
+++ b/src/test/ui/kindck/kindck-send-owned.stderr
@@ -1,8 +1,8 @@
 error[E0277]: `*mut u8` cannot be sent between threads safely
-  --> $DIR/kindck-send-owned.rs:12:5
+  --> $DIR/kindck-send-owned.rs:12:19
    |
 LL |     assert_send::<Box<*mut u8>>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ `*mut u8` cannot be sent between threads safely
+   |                   ^^^^^^^^^^^^ `*mut u8` cannot be sent between threads safely
    |
    = help: the trait `Send` is not implemented for `*mut u8`
    = note: required for `Unique<*mut u8>` to implement `Send`
diff --git a/src/test/ui/lazy-type-alias-impl-trait/branches.stderr b/src/test/ui/lazy-type-alias-impl-trait/branches.stderr
index 6b87da0c040d5..33f82448dd2ac 100644
--- a/src/test/ui/lazy-type-alias-impl-trait/branches.stderr
+++ b/src/test/ui/lazy-type-alias-impl-trait/branches.stderr
@@ -1,8 +1,10 @@
 error[E0277]: a value of type `Bar` cannot be built from an iterator over elements of type `_`
-  --> $DIR/branches.rs:19:28
+  --> $DIR/branches.rs:19:9
    |
 LL |         std::iter::empty().collect()
-   |                            ^^^^^^^ value of type `Bar` cannot be built from `std::iter::Iterator<Item=_>`
+   |         ^^^^^^^^^^^^^^^^^^ ------- required by a bound introduced by this call
+   |         |
+   |         value of type `Bar` cannot be built from `std::iter::Iterator<Item=_>`
    |
    = help: the trait `FromIterator<_>` is not implemented for `Bar`
 note: required by a bound in `collect`
diff --git a/src/test/ui/lazy-type-alias-impl-trait/recursion4.stderr b/src/test/ui/lazy-type-alias-impl-trait/recursion4.stderr
index 42a1f782d299d..57978edf2bf05 100644
--- a/src/test/ui/lazy-type-alias-impl-trait/recursion4.stderr
+++ b/src/test/ui/lazy-type-alias-impl-trait/recursion4.stderr
@@ -1,8 +1,10 @@
 error[E0277]: a value of type `Foo` cannot be built from an iterator over elements of type `_`
-  --> $DIR/recursion4.rs:10:28
+  --> $DIR/recursion4.rs:10:9
    |
 LL |     x = std::iter::empty().collect();
-   |                            ^^^^^^^ value of type `Foo` cannot be built from `std::iter::Iterator<Item=_>`
+   |         ^^^^^^^^^^^^^^^^^^ ------- required by a bound introduced by this call
+   |         |
+   |         value of type `Foo` cannot be built from `std::iter::Iterator<Item=_>`
    |
    = help: the trait `FromIterator<_>` is not implemented for `Foo`
 note: required by a bound in `collect`
@@ -12,10 +14,12 @@ LL |     fn collect<B: FromIterator<Self::Item>>(self) -> B
    |                   ^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `collect`
 
 error[E0277]: a value of type `impl Debug` cannot be built from an iterator over elements of type `_`
-  --> $DIR/recursion4.rs:19:28
+  --> $DIR/recursion4.rs:19:9
    |
 LL |     x = std::iter::empty().collect();
-   |                            ^^^^^^^ value of type `impl Debug` cannot be built from `std::iter::Iterator<Item=_>`
+   |         ^^^^^^^^^^^^^^^^^^ ------- required by a bound introduced by this call
+   |         |
+   |         value of type `impl Debug` cannot be built from `std::iter::Iterator<Item=_>`
    |
    = help: the trait `FromIterator<_>` is not implemented for `impl Debug`
 note: required by a bound in `collect`
diff --git a/src/test/ui/mismatched_types/method-help-unsatisfied-bound.stderr b/src/test/ui/mismatched_types/method-help-unsatisfied-bound.stderr
index c2515c40b1d77..36748fae13c94 100644
--- a/src/test/ui/mismatched_types/method-help-unsatisfied-bound.stderr
+++ b/src/test/ui/mismatched_types/method-help-unsatisfied-bound.stderr
@@ -1,8 +1,10 @@
 error[E0277]: `Foo` doesn't implement `Debug`
-  --> $DIR/method-help-unsatisfied-bound.rs:5:7
+  --> $DIR/method-help-unsatisfied-bound.rs:5:5
    |
 LL |     a.unwrap();
-   |       ^^^^^^ `Foo` cannot be formatted using `{:?}`
+   |     ^ ------ required by a bound introduced by this call
+   |     |
+   |     `Foo` cannot be formatted using `{:?}`
    |
    = help: the trait `Debug` is not implemented for `Foo`
    = note: add `#[derive(Debug)]` to `Foo` or manually `impl Debug for Foo`
diff --git a/src/test/ui/never_type/defaulted-never-note.fallback.stderr b/src/test/ui/never_type/defaulted-never-note.fallback.stderr
index 4c8b492247352..283aca1b084ef 100644
--- a/src/test/ui/never_type/defaulted-never-note.fallback.stderr
+++ b/src/test/ui/never_type/defaulted-never-note.fallback.stderr
@@ -1,8 +1,10 @@
 error[E0277]: the trait bound `!: ImplementedForUnitButNotNever` is not satisfied
-  --> $DIR/defaulted-never-note.rs:30:5
+  --> $DIR/defaulted-never-note.rs:30:9
    |
 LL |     foo(_x);
-   |     ^^^ the trait `ImplementedForUnitButNotNever` is not implemented for `!`
+   |     --- ^^ the trait `ImplementedForUnitButNotNever` is not implemented for `!`
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: the trait `ImplementedForUnitButNotNever` is implemented for `()`
    = note: this error might have been caused by changes to Rust's type-inference algorithm (see issue #48950 <https://github.com/rust-lang/rust/issues/48950> for more information)
diff --git a/src/test/ui/never_type/defaulted-never-note.rs b/src/test/ui/never_type/defaulted-never-note.rs
index aefc739a0a0b0..d30ffcd3846e7 100644
--- a/src/test/ui/never_type/defaulted-never-note.rs
+++ b/src/test/ui/never_type/defaulted-never-note.rs
@@ -32,6 +32,7 @@ fn smeg() {
     //[fallback]~| NOTE the trait `ImplementedForUnitButNotNever` is not implemented
     //[fallback]~| HELP trait `ImplementedForUnitButNotNever` is implemented for `()`
     //[fallback]~| NOTE this error might have been caused
+    //[fallback]~| NOTE required by a bound introduced by this call
     //[fallback]~| HELP did you intend
 }
 
diff --git a/src/test/ui/never_type/diverging-fallback-no-leak.fallback.stderr b/src/test/ui/never_type/diverging-fallback-no-leak.fallback.stderr
index dee2b1d704b86..3215c4669d5e3 100644
--- a/src/test/ui/never_type/diverging-fallback-no-leak.fallback.stderr
+++ b/src/test/ui/never_type/diverging-fallback-no-leak.fallback.stderr
@@ -1,8 +1,10 @@
 error[E0277]: the trait bound `!: Test` is not satisfied
-  --> $DIR/diverging-fallback-no-leak.rs:17:5
+  --> $DIR/diverging-fallback-no-leak.rs:17:23
    |
 LL |     unconstrained_arg(return);
-   |     ^^^^^^^^^^^^^^^^^ the trait `Test` is not implemented for `!`
+   |     ----------------- ^^^^^^ the trait `Test` is not implemented for `!`
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: the following other types implement trait `Test`:
              ()
diff --git a/src/test/ui/never_type/feature-gate-never_type_fallback.stderr b/src/test/ui/never_type/feature-gate-never_type_fallback.stderr
index 54abed383000d..6dc039fc35db7 100644
--- a/src/test/ui/never_type/feature-gate-never_type_fallback.stderr
+++ b/src/test/ui/never_type/feature-gate-never_type_fallback.stderr
@@ -1,8 +1,12 @@
 error[E0277]: the trait bound `(): T` is not satisfied
-  --> $DIR/feature-gate-never_type_fallback.rs:10:5
+  --> $DIR/feature-gate-never_type_fallback.rs:10:9
    |
 LL |     foo(panic!())
-   |     ^^^ the trait `T` is not implemented for `()`
+   |     --- ^^^^^^^^
+   |     |   |
+   |     |   the trait `T` is not implemented for `()`
+   |     |   this tail expression is of type `_`
+   |     required by a bound introduced by this call
    |
 note: required by a bound in `foo`
   --> $DIR/feature-gate-never_type_fallback.rs:13:16
diff --git a/src/test/ui/never_type/never-value-fallback-issue-66757.nofallback.stderr b/src/test/ui/never_type/never-value-fallback-issue-66757.nofallback.stderr
index e2045591390e1..06e902bca70fe 100644
--- a/src/test/ui/never_type/never-value-fallback-issue-66757.nofallback.stderr
+++ b/src/test/ui/never_type/never-value-fallback-issue-66757.nofallback.stderr
@@ -1,8 +1,10 @@
 error[E0277]: the trait bound `E: From<()>` is not satisfied
-  --> $DIR/never-value-fallback-issue-66757.rs:28:5
+  --> $DIR/never-value-fallback-issue-66757.rs:28:26
    |
 LL |     <E as From<_>>::from(never);
-   |     ^^^^^^^^^^^^^^^^^^^^ the trait `From<()>` is not implemented for `E`
+   |     -------------------- ^^^^^ the trait `From<()>` is not implemented for `E`
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: the trait `From<!>` is implemented for `E`
 
diff --git a/src/test/ui/no-send-res-ports.stderr b/src/test/ui/no-send-res-ports.stderr
index 249c2fe2fa74e..c864b93dbbbe1 100644
--- a/src/test/ui/no-send-res-ports.stderr
+++ b/src/test/ui/no-send-res-ports.stderr
@@ -1,10 +1,17 @@
 error[E0277]: `Rc<()>` cannot be sent between threads safely
-  --> $DIR/no-send-res-ports.rs:25:5
+  --> $DIR/no-send-res-ports.rs:25:19
    |
-LL |     thread::spawn(move|| {
-   |     ^^^^^^^^^^^^^ ------ within this `[closure@$DIR/no-send-res-ports.rs:25:19: 25:25]`
-   |     |
-   |     `Rc<()>` cannot be sent between threads safely
+LL |       thread::spawn(move|| {
+   |       ------------- ^-----
+   |       |             |
+   |  _____|_____________within this `[closure@$DIR/no-send-res-ports.rs:25:19: 25:25]`
+   | |     |
+   | |     required by a bound introduced by this call
+LL | |
+LL | |         let y = x;
+LL | |         println!("{:?}", y);
+LL | |     });
+   | |_____^ `Rc<()>` cannot be sent between threads safely
    |
    = help: within `[closure@$DIR/no-send-res-ports.rs:25:19: 25:25]`, the trait `Send` is not implemented for `Rc<()>`
 note: required because it appears within the type `Port<()>`
diff --git a/src/test/ui/not-clone-closure.stderr b/src/test/ui/not-clone-closure.stderr
index 37d94cf0ebd8c..f61ee661bb7ed 100644
--- a/src/test/ui/not-clone-closure.stderr
+++ b/src/test/ui/not-clone-closure.stderr
@@ -1,11 +1,13 @@
 error[E0277]: the trait bound `S: Clone` is not satisfied in `[closure@$DIR/not-clone-closure.rs:7:17: 7:24]`
-  --> $DIR/not-clone-closure.rs:11:23
+  --> $DIR/not-clone-closure.rs:11:17
    |
 LL |     let hello = move || {
    |                 ------- within this `[closure@$DIR/not-clone-closure.rs:7:17: 7:24]`
 ...
 LL |     let hello = hello.clone();
-   |                       ^^^^^ within `[closure@$DIR/not-clone-closure.rs:7:17: 7:24]`, the trait `Clone` is not implemented for `S`
+   |                 ^^^^^ ----- required by a bound introduced by this call
+   |                 |
+   |                 within `[closure@$DIR/not-clone-closure.rs:7:17: 7:24]`, the trait `Clone` is not implemented for `S`
    |
 note: required because it's used within this closure
   --> $DIR/not-clone-closure.rs:7:17
diff --git a/src/test/ui/not-panic/not-panic-safe-2.stderr b/src/test/ui/not-panic/not-panic-safe-2.stderr
index 43bb31afa6f54..3b0f83b3b9a47 100644
--- a/src/test/ui/not-panic/not-panic-safe-2.stderr
+++ b/src/test/ui/not-panic/not-panic-safe-2.stderr
@@ -1,8 +1,8 @@
 error[E0277]: the type `UnsafeCell<i32>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
-  --> $DIR/not-panic-safe-2.rs:10:5
+  --> $DIR/not-panic-safe-2.rs:10:14
    |
 LL |     assert::<Rc<RefCell<i32>>>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ `UnsafeCell<i32>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
+   |              ^^^^^^^^^^^^^^^^ `UnsafeCell<i32>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
    |
    = help: within `RefCell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<i32>`
    = note: required because it appears within the type `RefCell<i32>`
@@ -14,10 +14,10 @@ LL | fn assert<T: UnwindSafe + ?Sized>() {}
    |              ^^^^^^^^^^ required by this bound in `assert`
 
 error[E0277]: the type `UnsafeCell<isize>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
-  --> $DIR/not-panic-safe-2.rs:10:5
+  --> $DIR/not-panic-safe-2.rs:10:14
    |
 LL |     assert::<Rc<RefCell<i32>>>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ `UnsafeCell<isize>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
+   |              ^^^^^^^^^^^^^^^^ `UnsafeCell<isize>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
    |
    = help: within `RefCell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<isize>`
    = note: required because it appears within the type `Cell<isize>`
diff --git a/src/test/ui/not-panic/not-panic-safe-3.stderr b/src/test/ui/not-panic/not-panic-safe-3.stderr
index ef1d1baf58bfc..9e9a12764a4b6 100644
--- a/src/test/ui/not-panic/not-panic-safe-3.stderr
+++ b/src/test/ui/not-panic/not-panic-safe-3.stderr
@@ -1,8 +1,8 @@
 error[E0277]: the type `UnsafeCell<i32>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
-  --> $DIR/not-panic-safe-3.rs:10:5
+  --> $DIR/not-panic-safe-3.rs:10:14
    |
 LL |     assert::<Arc<RefCell<i32>>>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ `UnsafeCell<i32>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
+   |              ^^^^^^^^^^^^^^^^^ `UnsafeCell<i32>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
    |
    = help: within `RefCell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<i32>`
    = note: required because it appears within the type `RefCell<i32>`
@@ -14,10 +14,10 @@ LL | fn assert<T: UnwindSafe + ?Sized>() {}
    |              ^^^^^^^^^^ required by this bound in `assert`
 
 error[E0277]: the type `UnsafeCell<isize>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
-  --> $DIR/not-panic-safe-3.rs:10:5
+  --> $DIR/not-panic-safe-3.rs:10:14
    |
 LL |     assert::<Arc<RefCell<i32>>>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ `UnsafeCell<isize>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
+   |              ^^^^^^^^^^^^^^^^^ `UnsafeCell<isize>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
    |
    = help: within `RefCell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<isize>`
    = note: required because it appears within the type `Cell<isize>`
diff --git a/src/test/ui/not-panic/not-panic-safe-4.stderr b/src/test/ui/not-panic/not-panic-safe-4.stderr
index a398b44d339e7..fc1c594d0d422 100644
--- a/src/test/ui/not-panic/not-panic-safe-4.stderr
+++ b/src/test/ui/not-panic/not-panic-safe-4.stderr
@@ -1,8 +1,8 @@
 error[E0277]: the type `UnsafeCell<i32>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
-  --> $DIR/not-panic-safe-4.rs:9:5
+  --> $DIR/not-panic-safe-4.rs:9:14
    |
 LL |     assert::<&RefCell<i32>>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^ `UnsafeCell<i32>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
+   |              ^^^^^^^^^^^^^ `UnsafeCell<i32>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
    |
    = help: within `RefCell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<i32>`
    = note: required because it appears within the type `RefCell<i32>`
@@ -14,10 +14,10 @@ LL | fn assert<T: UnwindSafe + ?Sized>() {}
    |              ^^^^^^^^^^ required by this bound in `assert`
 
 error[E0277]: the type `UnsafeCell<isize>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
-  --> $DIR/not-panic-safe-4.rs:9:5
+  --> $DIR/not-panic-safe-4.rs:9:14
    |
 LL |     assert::<&RefCell<i32>>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^ `UnsafeCell<isize>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
+   |              ^^^^^^^^^^^^^ `UnsafeCell<isize>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
    |
    = help: within `RefCell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<isize>`
    = note: required because it appears within the type `Cell<isize>`
diff --git a/src/test/ui/not-panic/not-panic-safe-5.stderr b/src/test/ui/not-panic/not-panic-safe-5.stderr
index 9617d5dfde40d..cb78370b48a6c 100644
--- a/src/test/ui/not-panic/not-panic-safe-5.stderr
+++ b/src/test/ui/not-panic/not-panic-safe-5.stderr
@@ -1,8 +1,8 @@
 error[E0277]: the type `UnsafeCell<i32>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
-  --> $DIR/not-panic-safe-5.rs:9:5
+  --> $DIR/not-panic-safe-5.rs:9:14
    |
 LL |     assert::<*const UnsafeCell<i32>>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `UnsafeCell<i32>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
+   |              ^^^^^^^^^^^^^^^^^^^^^^ `UnsafeCell<i32>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
    |
    = help: the trait `RefUnwindSafe` is not implemented for `UnsafeCell<i32>`
    = note: required for `*const UnsafeCell<i32>` to implement `UnwindSafe`
diff --git a/src/test/ui/not-panic/not-panic-safe-6.stderr b/src/test/ui/not-panic/not-panic-safe-6.stderr
index 09204d942d235..7986e341eb01f 100644
--- a/src/test/ui/not-panic/not-panic-safe-6.stderr
+++ b/src/test/ui/not-panic/not-panic-safe-6.stderr
@@ -1,8 +1,8 @@
 error[E0277]: the type `UnsafeCell<i32>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
-  --> $DIR/not-panic-safe-6.rs:9:5
+  --> $DIR/not-panic-safe-6.rs:9:14
    |
 LL |     assert::<*mut RefCell<i32>>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ `UnsafeCell<i32>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
+   |              ^^^^^^^^^^^^^^^^^ `UnsafeCell<i32>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
    |
    = help: within `RefCell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<i32>`
    = note: required because it appears within the type `RefCell<i32>`
@@ -14,10 +14,10 @@ LL | fn assert<T: UnwindSafe + ?Sized>() {}
    |              ^^^^^^^^^^ required by this bound in `assert`
 
 error[E0277]: the type `UnsafeCell<isize>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
-  --> $DIR/not-panic-safe-6.rs:9:5
+  --> $DIR/not-panic-safe-6.rs:9:14
    |
 LL |     assert::<*mut RefCell<i32>>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ `UnsafeCell<isize>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
+   |              ^^^^^^^^^^^^^^^^^ `UnsafeCell<isize>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
    |
    = help: within `RefCell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<isize>`
    = note: required because it appears within the type `Cell<isize>`
diff --git a/src/test/ui/on-unimplemented/multiple-impls.stderr b/src/test/ui/on-unimplemented/multiple-impls.stderr
index 6e3601d7bf4b5..d47a398412fe4 100644
--- a/src/test/ui/on-unimplemented/multiple-impls.stderr
+++ b/src/test/ui/on-unimplemented/multiple-impls.stderr
@@ -1,8 +1,8 @@
 error[E0277]: the trait bound `[i32]: Index<u32>` is not satisfied
-  --> $DIR/multiple-impls.rs:33:18
+  --> $DIR/multiple-impls.rs:33:33
    |
 LL |     Index::index(&[] as &[i32], 2u32);
-   |     ------------ ^^^^^^^^^^^^^ trait message
+   |     ------------                ^^^^ trait message
    |     |
    |     required by a bound introduced by this call
    |
@@ -12,10 +12,10 @@ LL |     Index::index(&[] as &[i32], 2u32);
              <[i32] as Index<Foo<usize>>>
 
 error[E0277]: the trait bound `[i32]: Index<Foo<u32>>` is not satisfied
-  --> $DIR/multiple-impls.rs:35:18
+  --> $DIR/multiple-impls.rs:35:33
    |
 LL |     Index::index(&[] as &[i32], Foo(2u32));
-   |     ------------ ^^^^^^^^^^^^^ on impl for Foo
+   |     ------------                ^^^^^^^^^ on impl for Foo
    |     |
    |     required by a bound introduced by this call
    |
@@ -25,10 +25,10 @@ LL |     Index::index(&[] as &[i32], Foo(2u32));
              <[i32] as Index<Foo<usize>>>
 
 error[E0277]: the trait bound `[i32]: Index<Bar<u32>>` is not satisfied
-  --> $DIR/multiple-impls.rs:37:18
+  --> $DIR/multiple-impls.rs:37:33
    |
 LL |     Index::index(&[] as &[i32], Bar(2u32));
-   |     ------------ ^^^^^^^^^^^^^ on impl for Bar
+   |     ------------                ^^^^^^^^^ on impl for Bar
    |     |
    |     required by a bound introduced by this call
    |
diff --git a/src/test/ui/on-unimplemented/on-impl.stderr b/src/test/ui/on-unimplemented/on-impl.stderr
index 396c062cfe2ac..01315b854098e 100644
--- a/src/test/ui/on-unimplemented/on-impl.stderr
+++ b/src/test/ui/on-unimplemented/on-impl.stderr
@@ -1,8 +1,8 @@
 error[E0277]: the trait bound `[i32]: Index<u32>` is not satisfied
-  --> $DIR/on-impl.rs:22:25
+  --> $DIR/on-impl.rs:22:47
    |
 LL |     Index::<u32>::index(&[1, 2, 3] as &[i32], 2u32);
-   |     ------------------- ^^^^^^^^^^^^^^^^^^^^ a usize is required to index into a slice
+   |     -------------------                       ^^^^ a usize is required to index into a slice
    |     |
    |     required by a bound introduced by this call
    |
diff --git a/src/test/ui/parser/issues/issue-67377-invalid-syntax-in-enum-discriminant.stderr b/src/test/ui/parser/issues/issue-67377-invalid-syntax-in-enum-discriminant.stderr
index 85c9fe409dbe9..a00f37ed6069c 100644
--- a/src/test/ui/parser/issues/issue-67377-invalid-syntax-in-enum-discriminant.stderr
+++ b/src/test/ui/parser/issues/issue-67377-invalid-syntax-in-enum-discriminant.stderr
@@ -107,10 +107,10 @@ LL |         V = [Vec::new; { [0].len() ].len() as isize,
    |             closing delimiter possibly meant for this
 
 error[E0282]: type annotations needed
-  --> $DIR/issue-67377-invalid-syntax-in-enum-discriminant.rs:15:29
+  --> $DIR/issue-67377-invalid-syntax-in-enum-discriminant.rs:15:26
    |
 LL |         V = [Vec::new; { [].len()  ].len() as isize,
-   |                             ^^^ cannot infer type for type parameter `T`
+   |                          ^^ cannot infer type for type parameter `T`
 
 error[E0282]: type annotations needed
   --> $DIR/issue-67377-invalid-syntax-in-enum-discriminant.rs:26:14
diff --git a/src/test/ui/pattern/move-ref-patterns/move-ref-patterns-closure-captures.stderr b/src/test/ui/pattern/move-ref-patterns/move-ref-patterns-closure-captures.stderr
index d96e863939c02..eba65a61803d0 100644
--- a/src/test/ui/pattern/move-ref-patterns/move-ref-patterns-closure-captures.stderr
+++ b/src/test/ui/pattern/move-ref-patterns/move-ref-patterns-closure-captures.stderr
@@ -8,7 +8,15 @@ LL |         drop::<U>(_x1);
    |                   --- closure is `FnOnce` because it moves the variable `_x1` out of its environment
 ...
 LL |     accept_fn_mut(&c1);
-   |     ------------- the requirement to implement `FnMut` derives from here
+   |     ------------- --- the requirement to implement `FnMut` derives from here
+   |     |
+   |     required by a bound introduced by this call
+   |
+note: required by a bound in `accept_fn_mut`
+  --> $DIR/move-ref-patterns-closure-captures.rs:4:31
+   |
+LL |     fn accept_fn_mut(_: &impl FnMut()) {}
+   |                               ^^^^^^^ required by this bound in `accept_fn_mut`
 
 error[E0525]: expected a closure that implements the `Fn` trait, but this closure only implements `FnOnce`
   --> $DIR/move-ref-patterns-closure-captures.rs:9:14
@@ -20,7 +28,15 @@ LL |         drop::<U>(_x1);
    |                   --- closure is `FnOnce` because it moves the variable `_x1` out of its environment
 ...
 LL |     accept_fn(&c1);
-   |     --------- the requirement to implement `Fn` derives from here
+   |     --------- --- the requirement to implement `Fn` derives from here
+   |     |
+   |     required by a bound introduced by this call
+   |
+note: required by a bound in `accept_fn`
+  --> $DIR/move-ref-patterns-closure-captures.rs:5:27
+   |
+LL |     fn accept_fn(_: &impl Fn()) {}
+   |                           ^^^^ required by this bound in `accept_fn`
 
 error[E0525]: expected a closure that implements the `Fn` trait, but this closure only implements `FnMut`
   --> $DIR/move-ref-patterns-closure-captures.rs:20:14
@@ -32,7 +48,15 @@ LL |         drop::<&mut U>(_x2);
    |                        --- closure is `FnMut` because it mutates the variable `_x2` here
 ...
 LL |     accept_fn(&c2);
-   |     --------- the requirement to implement `Fn` derives from here
+   |     --------- --- the requirement to implement `Fn` derives from here
+   |     |
+   |     required by a bound introduced by this call
+   |
+note: required by a bound in `accept_fn`
+  --> $DIR/move-ref-patterns-closure-captures.rs:5:27
+   |
+LL |     fn accept_fn(_: &impl Fn()) {}
+   |                           ^^^^ required by this bound in `accept_fn`
 
 error: aborting due to 3 previous errors
 
diff --git a/src/test/ui/proc-macro/signature.stderr b/src/test/ui/proc-macro/signature.stderr
index a6bd98ddb1977..78b0beff0da39 100644
--- a/src/test/ui/proc-macro/signature.stderr
+++ b/src/test/ui/proc-macro/signature.stderr
@@ -5,7 +5,10 @@ LL | / pub unsafe extern "C" fn foo(a: i32, b: u32) -> u32 {
 LL | |
 LL | |     loop {}
 LL | | }
-   | |_^ call the function in a closure: `|| unsafe { /* code */ }`
+   | | ^
+   | | |
+   | |_call the function in a closure: `|| unsafe { /* code */ }`
+   |   required by a bound introduced by this call
    |
    = help: the trait `Fn<(proc_macro::TokenStream,)>` is not implemented for `unsafe extern "C" fn(i32, u32) -> u32 {foo}`
    = note: unsafe function cannot be called generically without an unsafe block
diff --git a/src/test/ui/range/range-1.stderr b/src/test/ui/range/range-1.stderr
index 0e3bb66ab61e9..aaea91ce0cbae 100644
--- a/src/test/ui/range/range-1.stderr
+++ b/src/test/ui/range/range-1.stderr
@@ -27,7 +27,7 @@ error[E0277]: the size for values of type `[{integer}]` cannot be known at compi
   --> $DIR/range-1.rs:14:17
    |
 LL |     let range = *arr..;
-   |                 ^^^^^^ doesn't have a size known at compile-time
+   |                 ^^^^ doesn't have a size known at compile-time
    |
    = help: the trait `Sized` is not implemented for `[{integer}]`
 note: required by a bound in `RangeFrom`
diff --git a/src/test/ui/rfc-2632-const-trait-impl/const-default-method-bodies.stderr b/src/test/ui/rfc-2632-const-trait-impl/const-default-method-bodies.stderr
index ec724cc9675f1..fddc8d37f2ff7 100644
--- a/src/test/ui/rfc-2632-const-trait-impl/const-default-method-bodies.stderr
+++ b/src/test/ui/rfc-2632-const-trait-impl/const-default-method-bodies.stderr
@@ -1,14 +1,16 @@
 error[E0277]: the trait bound `NonConstImpl: ~const ConstDefaultFn` is not satisfied
-  --> $DIR/const-default-method-bodies.rs:24:18
+  --> $DIR/const-default-method-bodies.rs:24:5
    |
 LL |     NonConstImpl.a();
-   |                  ^ the trait `~const ConstDefaultFn` is not implemented for `NonConstImpl`
+   |     ^^^^^^^^^^^^ - required by a bound introduced by this call
+   |     |
+   |     the trait `~const ConstDefaultFn` is not implemented for `NonConstImpl`
    |
 note: the trait `ConstDefaultFn` is implemented for `NonConstImpl`, but that implementation is not `const`
-  --> $DIR/const-default-method-bodies.rs:24:18
+  --> $DIR/const-default-method-bodies.rs:24:5
    |
 LL |     NonConstImpl.a();
-   |                  ^
+   |     ^^^^^^^^^^^^
 help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement
    |
 LL | const fn test() where NonConstImpl: ~const ConstDefaultFn {
diff --git a/src/test/ui/rfc-2632-const-trait-impl/const-drop-fail.precise.stderr b/src/test/ui/rfc-2632-const-trait-impl/const-drop-fail.precise.stderr
index ac61c3279217b..2295a822fa48b 100644
--- a/src/test/ui/rfc-2632-const-trait-impl/const-drop-fail.precise.stderr
+++ b/src/test/ui/rfc-2632-const-trait-impl/const-drop-fail.precise.stderr
@@ -5,7 +5,7 @@ LL |         const _: () = check($exp);
    |                       ----- required by a bound introduced by this call
 ...
 LL |     NonTrivialDrop,
-   |     ^^^^^^^^^^^^^^ expected an implementor of trait `~const Destruct`
+   |     ^^^^^^^^^^^^^^ the trait `~const Destruct` is not implemented for `NonTrivialDrop`
    |
    = note: the trait bound `NonTrivialDrop: ~const Destruct` is not satisfied
 note: required by a bound in `check`
@@ -52,7 +52,7 @@ LL |         const _: () = check($exp);
    |                       ----- required by a bound introduced by this call
 ...
 LL |     ConstDropImplWithBounds::<NonTrivialDrop>(PhantomData),
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected an implementor of trait `~const Destruct`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `~const Destruct` is not implemented for `ConstDropImplWithBounds<NonTrivialDrop>`
    |
 note: required for `ConstDropImplWithBounds<NonTrivialDrop>` to implement `~const Destruct`
   --> $DIR/const-drop-fail.rs:28:25
diff --git a/src/test/ui/rfc-2632-const-trait-impl/const-drop-fail.stock.stderr b/src/test/ui/rfc-2632-const-trait-impl/const-drop-fail.stock.stderr
index ac61c3279217b..2295a822fa48b 100644
--- a/src/test/ui/rfc-2632-const-trait-impl/const-drop-fail.stock.stderr
+++ b/src/test/ui/rfc-2632-const-trait-impl/const-drop-fail.stock.stderr
@@ -5,7 +5,7 @@ LL |         const _: () = check($exp);
    |                       ----- required by a bound introduced by this call
 ...
 LL |     NonTrivialDrop,
-   |     ^^^^^^^^^^^^^^ expected an implementor of trait `~const Destruct`
+   |     ^^^^^^^^^^^^^^ the trait `~const Destruct` is not implemented for `NonTrivialDrop`
    |
    = note: the trait bound `NonTrivialDrop: ~const Destruct` is not satisfied
 note: required by a bound in `check`
@@ -52,7 +52,7 @@ LL |         const _: () = check($exp);
    |                       ----- required by a bound introduced by this call
 ...
 LL |     ConstDropImplWithBounds::<NonTrivialDrop>(PhantomData),
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected an implementor of trait `~const Destruct`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `~const Destruct` is not implemented for `ConstDropImplWithBounds<NonTrivialDrop>`
    |
 note: required for `ConstDropImplWithBounds<NonTrivialDrop>` to implement `~const Destruct`
   --> $DIR/const-drop-fail.rs:28:25
diff --git a/src/test/ui/rfc-2632-const-trait-impl/cross-crate.gatednc.stderr b/src/test/ui/rfc-2632-const-trait-impl/cross-crate.gatednc.stderr
index 174c62912fcee..d4fa44b4bfcb5 100644
--- a/src/test/ui/rfc-2632-const-trait-impl/cross-crate.gatednc.stderr
+++ b/src/test/ui/rfc-2632-const-trait-impl/cross-crate.gatednc.stderr
@@ -1,14 +1,16 @@
 error[E0277]: the trait bound `cross_crate::NonConst: ~const cross_crate::MyTrait` is not satisfied
-  --> $DIR/cross-crate.rs:17:14
+  --> $DIR/cross-crate.rs:17:5
    |
 LL |     NonConst.func();
-   |              ^^^^ the trait `~const cross_crate::MyTrait` is not implemented for `cross_crate::NonConst`
+   |     ^^^^^^^^ ---- required by a bound introduced by this call
+   |     |
+   |     the trait `~const cross_crate::MyTrait` is not implemented for `cross_crate::NonConst`
    |
 note: the trait `cross_crate::MyTrait` is implemented for `cross_crate::NonConst`, but that implementation is not `const`
-  --> $DIR/cross-crate.rs:17:14
+  --> $DIR/cross-crate.rs:17:5
    |
 LL |     NonConst.func();
-   |              ^^^^
+   |     ^^^^^^^^
 help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement
    |
 LL | const fn const_context() where cross_crate::NonConst: ~const cross_crate::MyTrait {
diff --git a/src/test/ui/rfc-2632-const-trait-impl/cross-crate.stocknc.stderr b/src/test/ui/rfc-2632-const-trait-impl/cross-crate.stocknc.stderr
index 4619dd1138e1f..71ecd9b06945f 100644
--- a/src/test/ui/rfc-2632-const-trait-impl/cross-crate.stocknc.stderr
+++ b/src/test/ui/rfc-2632-const-trait-impl/cross-crate.stocknc.stderr
@@ -1,14 +1,16 @@
 error[E0277]: the trait bound `cross_crate::NonConst: cross_crate::MyTrait` is not satisfied
-  --> $DIR/cross-crate.rs:17:14
+  --> $DIR/cross-crate.rs:17:5
    |
 LL |     NonConst.func();
-   |              ^^^^ the trait `~const cross_crate::MyTrait` is not implemented for `cross_crate::NonConst`
+   |     ^^^^^^^^ ---- required by a bound introduced by this call
+   |     |
+   |     the trait `~const cross_crate::MyTrait` is not implemented for `cross_crate::NonConst`
    |
 note: the trait `cross_crate::MyTrait` is implemented for `cross_crate::NonConst`, but that implementation is not `const`
-  --> $DIR/cross-crate.rs:17:14
+  --> $DIR/cross-crate.rs:17:5
    |
 LL |     NonConst.func();
-   |              ^^^^
+   |     ^^^^^^^^
 help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement
    |
 LL | const fn const_context() where cross_crate::NonConst: ~const cross_crate::MyTrait {
diff --git a/src/test/ui/rfc-2632-const-trait-impl/default-method-body-is-const-same-trait-ck.stderr b/src/test/ui/rfc-2632-const-trait-impl/default-method-body-is-const-same-trait-ck.stderr
index b229053eb50cf..85285ba849777 100644
--- a/src/test/ui/rfc-2632-const-trait-impl/default-method-body-is-const-same-trait-ck.stderr
+++ b/src/test/ui/rfc-2632-const-trait-impl/default-method-body-is-const-same-trait-ck.stderr
@@ -1,14 +1,16 @@
 error[E0277]: the trait bound `(): ~const Tr` is not satisfied
-  --> $DIR/default-method-body-is-const-same-trait-ck.rs:8:12
+  --> $DIR/default-method-body-is-const-same-trait-ck.rs:8:9
    |
 LL |         ().a()
-   |            ^ the trait `~const Tr` is not implemented for `()`
+   |         ^^ - required by a bound introduced by this call
+   |         |
+   |         the trait `~const Tr` is not implemented for `()`
    |
 note: the trait `Tr` is implemented for `()`, but that implementation is not `const`
-  --> $DIR/default-method-body-is-const-same-trait-ck.rs:8:12
+  --> $DIR/default-method-body-is-const-same-trait-ck.rs:8:9
    |
 LL |         ().a()
-   |            ^
+   |         ^^
 help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement
    |
 LL | pub trait Tr where (): ~const Tr {
diff --git a/src/test/ui/rfc-2632-const-trait-impl/trait-where-clause.stderr b/src/test/ui/rfc-2632-const-trait-impl/trait-where-clause.stderr
index d5b2d26973096..fd5fe25ddcfb4 100644
--- a/src/test/ui/rfc-2632-const-trait-impl/trait-where-clause.stderr
+++ b/src/test/ui/rfc-2632-const-trait-impl/trait-where-clause.stderr
@@ -20,16 +20,16 @@ LL | const fn test1<T: ~const Foo + Bar + ~const Bar>() {
    |                                    ++++++++++++
 
 error[E0277]: the trait bound `T: ~const Bar` is not satisfied
-  --> $DIR/trait-where-clause.rs:15:5
+  --> $DIR/trait-where-clause.rs:15:12
    |
 LL |     T::c::<T>();
-   |     ^^^^^^^^^ the trait `~const Bar` is not implemented for `T`
+   |            ^ the trait `~const Bar` is not implemented for `T`
    |
 note: the trait `Bar` is implemented for `T`, but that implementation is not `const`
-  --> $DIR/trait-where-clause.rs:15:5
+  --> $DIR/trait-where-clause.rs:15:12
    |
 LL |     T::c::<T>();
-   |     ^^^^^^^^^
+   |            ^
 note: required by a bound in `Foo::c`
   --> $DIR/trait-where-clause.rs:8:13
    |
@@ -57,10 +57,10 @@ LL | fn test3<T: Foo + Bar>() {
    |                 +++++
 
 error[E0277]: the trait bound `T: Bar` is not satisfied
-  --> $DIR/trait-where-clause.rs:29:5
+  --> $DIR/trait-where-clause.rs:29:12
    |
 LL |     T::c::<T>();
-   |     ^^^^^^^^^ the trait `Bar` is not implemented for `T`
+   |            ^ the trait `Bar` is not implemented for `T`
    |
 note: required by a bound in `Foo::c`
   --> $DIR/trait-where-clause.rs:8:13
diff --git a/src/test/ui/stats/hir-stats.stderr b/src/test/ui/stats/hir-stats.stderr
index 61cb7b25e4981..eb828bb9a2c17 100644
--- a/src/test/ui/stats/hir-stats.stderr
+++ b/src/test/ui/stats/hir-stats.stderr
@@ -4,58 +4,58 @@ PRE EXPANSION AST STATS
 Name                Accumulated Size         Count     Item Size
 ----------------------------------------------------------------
 ExprField                 48 ( 0.6%)             1            48
-Attribute                 64 ( 0.7%)             2            32
+Crate                     56 ( 0.7%)             1            56
+Attribute                 64 ( 0.8%)             2            32
 - Normal                    32 ( 0.4%)             1
 - DocComment                32 ( 0.4%)             1
-GenericArgs               64 ( 0.7%)             1            64
-- AngleBracketed            64 ( 0.7%)             1
-Local                     72 ( 0.8%)             1            72
-WherePredicate            72 ( 0.8%)             1            72
-- BoundPredicate            72 ( 0.8%)             1
-Crate                     72 ( 0.8%)             1            72
+GenericArgs               64 ( 0.8%)             1            64
+- AngleBracketed            64 ( 0.8%)             1
+Local                     72 ( 0.9%)             1            72
+WherePredicate            72 ( 0.9%)             1            72
+- BoundPredicate            72 ( 0.9%)             1
 Arm                       96 ( 1.1%)             2            48
-ForeignItem              112 ( 1.3%)             1           112
-- Fn                       112 ( 1.3%)             1
-FieldDef                 160 ( 1.8%)             2            80
-Stmt                     160 ( 1.8%)             5            32
+ForeignItem               96 ( 1.1%)             1            96
+- Fn                        96 ( 1.1%)             1
+FieldDef                 160 ( 1.9%)             2            80
+Stmt                     160 ( 1.9%)             5            32
 - Local                     32 ( 0.4%)             1
 - MacCall                   32 ( 0.4%)             1
 - Expr                      96 ( 1.1%)             3
-Param                    160 ( 1.8%)             4            40
-FnDecl                   200 ( 2.3%)             5            40
+Param                    160 ( 1.9%)             4            40
+FnDecl                   200 ( 2.4%)             5            40
 Variant                  240 ( 2.8%)             2           120
-Block                    288 ( 3.3%)             6            48
-GenericBound             352 ( 4.0%)             4            88
-- Trait                    352 ( 4.0%)             4
-AssocItem                480 ( 5.5%)             4           120
-- TyAlias                  240 ( 2.8%)             2
-- Fn                       240 ( 2.8%)             2
-GenericParam             520 ( 6.0%)             5           104
-PathSegment              720 ( 8.3%)            30            24
-Expr                     832 ( 9.6%)             8           104
+Block                    288 ( 3.4%)             6            48
+GenericBound             352 ( 4.2%)             4            88
+- Trait                    352 ( 4.2%)             4
+AssocItem                416 ( 4.9%)             4           104
+- TyAlias                  208 ( 2.5%)             2
+- Fn                       208 ( 2.5%)             2
+GenericParam             520 ( 6.1%)             5           104
+PathSegment              720 ( 8.5%)            30            24
+Expr                     832 ( 9.8%)             8           104
 - Path                     104 ( 1.2%)             1
 - Match                    104 ( 1.2%)             1
 - Struct                   104 ( 1.2%)             1
-- Lit                      208 ( 2.4%)             2
-- Block                    312 ( 3.6%)             3
-Pat                      840 ( 9.7%)             7           120
+- Lit                      208 ( 2.5%)             2
+- Block                    312 ( 3.7%)             3
+Pat                      840 ( 9.9%)             7           120
 - Struct                   120 ( 1.4%)             1
 - Wild                     120 ( 1.4%)             1
-- Ident                    600 ( 6.9%)             5
-Ty                     1_344 (15.5%)            14            96
+- Ident                    600 ( 7.1%)             5
+Ty                     1_344 (15.9%)            14            96
 - Rptr                      96 ( 1.1%)             1
 - Ptr                       96 ( 1.1%)             1
-- ImplicitSelf             192 ( 2.2%)             2
-- Path                     960 (11.0%)            10
-Item                   1_800 (20.7%)             9           200
-- Trait                    200 ( 2.3%)             1
-- Enum                     200 ( 2.3%)             1
-- ForeignMod               200 ( 2.3%)             1
-- Impl                     200 ( 2.3%)             1
-- Fn                       400 ( 4.6%)             2
-- Use                      600 ( 6.9%)             3
+- ImplicitSelf             192 ( 2.3%)             2
+- Path                     960 (11.4%)            10
+Item                   1_656 (19.6%)             9           184
+- Trait                    184 ( 2.2%)             1
+- Enum                     184 ( 2.2%)             1
+- ForeignMod               184 ( 2.2%)             1
+- Impl                     184 ( 2.2%)             1
+- Fn                       368 ( 4.4%)             2
+- Use                      552 ( 6.5%)             3
 ----------------------------------------------------------------
-Total                  8_696
+Total                  8_456
 
 
 POST EXPANSION AST STATS
@@ -63,15 +63,15 @@ POST EXPANSION AST STATS
 Name                Accumulated Size         Count     Item Size
 ----------------------------------------------------------------
 ExprField                 48 ( 0.5%)             1            48
+Crate                     56 ( 0.6%)             1            56
 GenericArgs               64 ( 0.7%)             1            64
 - AngleBracketed            64 ( 0.7%)             1
 Local                     72 ( 0.8%)             1            72
 WherePredicate            72 ( 0.8%)             1            72
 - BoundPredicate            72 ( 0.8%)             1
-Crate                     72 ( 0.8%)             1            72
 Arm                       96 ( 1.0%)             2            48
-ForeignItem              112 ( 1.2%)             1           112
-- Fn                       112 ( 1.2%)             1
+ForeignItem               96 ( 1.0%)             1            96
+- Fn                        96 ( 1.0%)             1
 InlineAsm                120 ( 1.3%)             1           120
 Attribute                128 ( 1.4%)             4            32
 - DocComment                32 ( 0.3%)             1
@@ -82,42 +82,42 @@ Stmt                     160 ( 1.7%)             5            32
 - Semi                      32 ( 0.3%)             1
 - Expr                      96 ( 1.0%)             3
 Param                    160 ( 1.7%)             4            40
-FnDecl                   200 ( 2.1%)             5            40
-Variant                  240 ( 2.5%)             2           120
-Block                    288 ( 3.0%)             6            48
-GenericBound             352 ( 3.7%)             4            88
-- Trait                    352 ( 3.7%)             4
-AssocItem                480 ( 5.1%)             4           120
-- TyAlias                  240 ( 2.5%)             2
-- Fn                       240 ( 2.5%)             2
-GenericParam             520 ( 5.5%)             5           104
-PathSegment              792 ( 8.4%)            33            24
-Pat                      840 ( 8.9%)             7           120
+FnDecl                   200 ( 2.2%)             5            40
+Variant                  240 ( 2.6%)             2           120
+Block                    288 ( 3.1%)             6            48
+GenericBound             352 ( 3.8%)             4            88
+- Trait                    352 ( 3.8%)             4
+AssocItem                416 ( 4.5%)             4           104
+- TyAlias                  208 ( 2.3%)             2
+- Fn                       208 ( 2.3%)             2
+GenericParam             520 ( 5.7%)             5           104
+PathSegment              792 ( 8.6%)            33            24
+Pat                      840 ( 9.1%)             7           120
 - Struct                   120 ( 1.3%)             1
 - Wild                     120 ( 1.3%)             1
-- Ident                    600 ( 6.3%)             5
-Expr                     936 ( 9.9%)             9           104
+- Ident                    600 ( 6.5%)             5
+Expr                     936 (10.2%)             9           104
 - Path                     104 ( 1.1%)             1
 - Match                    104 ( 1.1%)             1
 - Struct                   104 ( 1.1%)             1
 - InlineAsm                104 ( 1.1%)             1
-- Lit                      208 ( 2.2%)             2
-- Block                    312 ( 3.3%)             3
-Ty                     1_344 (14.2%)            14            96
+- Lit                      208 ( 2.3%)             2
+- Block                    312 ( 3.4%)             3
+Ty                     1_344 (14.6%)            14            96
 - Rptr                      96 ( 1.0%)             1
 - Ptr                       96 ( 1.0%)             1
-- ImplicitSelf             192 ( 2.0%)             2
-- Path                     960 (10.2%)            10
-Item                   2_200 (23.3%)            11           200
-- Trait                    200 ( 2.1%)             1
-- Enum                     200 ( 2.1%)             1
-- ExternCrate              200 ( 2.1%)             1
-- ForeignMod               200 ( 2.1%)             1
-- Impl                     200 ( 2.1%)             1
-- Fn                       400 ( 4.2%)             2
-- Use                      800 ( 8.5%)             4
+- ImplicitSelf             192 ( 2.1%)             2
+- Path                     960 (10.5%)            10
+Item                   2_024 (22.0%)            11           184
+- Trait                    184 ( 2.0%)             1
+- Enum                     184 ( 2.0%)             1
+- ExternCrate              184 ( 2.0%)             1
+- ForeignMod               184 ( 2.0%)             1
+- Impl                     184 ( 2.0%)             1
+- Fn                       368 ( 4.0%)             2
+- Use                      736 ( 8.0%)             4
 ----------------------------------------------------------------
-Total                  9_456
+Total                  9_184
 
 
 HIR STATS
diff --git a/src/test/ui/suggestions/expected-boxed-future-isnt-pinned.stderr b/src/test/ui/suggestions/expected-boxed-future-isnt-pinned.stderr
index 71facf57e8d65..e43a4e79bfe8c 100644
--- a/src/test/ui/suggestions/expected-boxed-future-isnt-pinned.stderr
+++ b/src/test/ui/suggestions/expected-boxed-future-isnt-pinned.stderr
@@ -46,10 +46,12 @@ LL |     pub const fn new(pointer: P) -> Pin<P> {
    |                  ^^^
 
 error[E0277]: `dyn Future<Output = i32> + Send` cannot be unpinned
-  --> $DIR/expected-boxed-future-isnt-pinned.rs:19:5
+  --> $DIR/expected-boxed-future-isnt-pinned.rs:19:14
    |
 LL |     Pin::new(x)
-   |     ^^^^^^^^ the trait `Unpin` is not implemented for `dyn Future<Output = i32> + Send`
+   |     -------- ^ the trait `Unpin` is not implemented for `dyn Future<Output = i32> + Send`
+   |     |
+   |     required by a bound introduced by this call
    |
    = note: consider using `Box::pin`
 note: required by a bound in `Pin::<P>::new`
@@ -59,10 +61,12 @@ LL | impl<P: Deref<Target: Unpin>> Pin<P> {
    |                       ^^^^^ required by this bound in `Pin::<P>::new`
 
 error[E0277]: `dyn Future<Output = i32> + Send` cannot be unpinned
-  --> $DIR/expected-boxed-future-isnt-pinned.rs:24:5
+  --> $DIR/expected-boxed-future-isnt-pinned.rs:24:14
    |
 LL |     Pin::new(Box::new(x))
-   |     ^^^^^^^^ the trait `Unpin` is not implemented for `dyn Future<Output = i32> + Send`
+   |     -------- ^^^^^^^^^^^ the trait `Unpin` is not implemented for `dyn Future<Output = i32> + Send`
+   |     |
+   |     required by a bound introduced by this call
    |
    = note: consider using `Box::pin`
 note: required by a bound in `Pin::<P>::new`
diff --git a/src/test/ui/suggestions/imm-ref-trait-object-literal-bound-regions.stderr b/src/test/ui/suggestions/imm-ref-trait-object-literal-bound-regions.stderr
index ba6af8f15fa89..864ab053520db 100644
--- a/src/test/ui/suggestions/imm-ref-trait-object-literal-bound-regions.stderr
+++ b/src/test/ui/suggestions/imm-ref-trait-object-literal-bound-regions.stderr
@@ -1,8 +1,10 @@
 error[E0277]: the trait bound `for<'b> &'b S: Trait` is not satisfied
-  --> $DIR/imm-ref-trait-object-literal-bound-regions.rs:17:5
+  --> $DIR/imm-ref-trait-object-literal-bound-regions.rs:17:14
    |
 LL |     foo::<S>(s);
-   |     ^^^^^^^^ the trait `for<'b> Trait` is not implemented for `&'b S`
+   |     -------- ^ the trait `for<'b> Trait` is not implemented for `&'b S`
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: the trait `Trait` is implemented for `&'a mut S`
    = note: `for<'b> Trait` is implemented for `&'b mut S`, but not for `&'b S`
diff --git a/src/test/ui/suggestions/imm-ref-trait-object-literal.stderr b/src/test/ui/suggestions/imm-ref-trait-object-literal.stderr
index 5f3f62a7b7570..e01102e3864ea 100644
--- a/src/test/ui/suggestions/imm-ref-trait-object-literal.stderr
+++ b/src/test/ui/suggestions/imm-ref-trait-object-literal.stderr
@@ -21,7 +21,7 @@ error[E0277]: the trait bound `S: Trait` is not satisfied
   --> $DIR/imm-ref-trait-object-literal.rs:13:7
    |
 LL |   foo(s);
-   |   --- ^ expected an implementor of trait `Trait`
+   |   --- ^ the trait `Trait` is not implemented for `S`
    |   |
    |   required by a bound introduced by this call
    |
diff --git a/src/test/ui/suggestions/issue-62843.stderr b/src/test/ui/suggestions/issue-62843.stderr
index 607e7992b9f06..62f0943d4c9d9 100644
--- a/src/test/ui/suggestions/issue-62843.stderr
+++ b/src/test/ui/suggestions/issue-62843.stderr
@@ -2,7 +2,7 @@ error[E0277]: expected a `FnMut<(char,)>` closure, found `String`
   --> $DIR/issue-62843.rs:4:32
    |
 LL |     println!("{:?}", line.find(pattern));
-   |                           ---- ^^^^^^^ expected an implementor of trait `Pattern<'_>`
+   |                           ---- ^^^^^^^ the trait `Pattern<'_>` is not implemented for `String`
    |                           |
    |                           required by a bound introduced by this call
    |
diff --git a/src/test/ui/suggestions/issue-71394-no-from-impl.stderr b/src/test/ui/suggestions/issue-71394-no-from-impl.stderr
index a5e6f5b5ffcb0..684db23e1355f 100644
--- a/src/test/ui/suggestions/issue-71394-no-from-impl.stderr
+++ b/src/test/ui/suggestions/issue-71394-no-from-impl.stderr
@@ -1,8 +1,10 @@
 error[E0277]: the trait bound `&[i8]: From<&[u8]>` is not satisfied
-  --> $DIR/issue-71394-no-from-impl.rs:3:25
+  --> $DIR/issue-71394-no-from-impl.rs:3:20
    |
 LL |     let _: &[i8] = data.into();
-   |                         ^^^^ the trait `From<&[u8]>` is not implemented for `&[i8]`
+   |                    ^^^^ ---- required by a bound introduced by this call
+   |                    |
+   |                    the trait `From<&[u8]>` is not implemented for `&[i8]`
    |
    = help: the following other types implement trait `From<T>`:
              <[T; LANES] as From<Simd<T, LANES>>>
diff --git a/src/test/ui/suggestions/issue-84973-2.stderr b/src/test/ui/suggestions/issue-84973-2.stderr
index 2c54ea6724505..513bf28fb5878 100644
--- a/src/test/ui/suggestions/issue-84973-2.stderr
+++ b/src/test/ui/suggestions/issue-84973-2.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `i32: Tr` is not satisfied
   --> $DIR/issue-84973-2.rs:11:9
    |
 LL |     foo(a);
-   |     --- ^ expected an implementor of trait `Tr`
+   |     --- ^ the trait `Tr` is not implemented for `i32`
    |     |
    |     required by a bound introduced by this call
    |
diff --git a/src/test/ui/suggestions/issue-84973-blacklist.stderr b/src/test/ui/suggestions/issue-84973-blacklist.stderr
index ae0d3efca4727..c20cc816484b4 100644
--- a/src/test/ui/suggestions/issue-84973-blacklist.stderr
+++ b/src/test/ui/suggestions/issue-84973-blacklist.stderr
@@ -31,10 +31,12 @@ LL | #[derive(Clone)]
    |
 
 error[E0277]: `[static generator@$DIR/issue-84973-blacklist.rs:17:13: 17:22]` cannot be unpinned
-  --> $DIR/issue-84973-blacklist.rs:17:5
+  --> $DIR/issue-84973-blacklist.rs:17:13
    |
 LL |     f_unpin(static || { yield; });
-   |     ^^^^^^^ the trait `Unpin` is not implemented for `[static generator@$DIR/issue-84973-blacklist.rs:17:13: 17:22]`
+   |     ------- ^^^^^^^^^^^^^^^^^^^^ the trait `Unpin` is not implemented for `[static generator@$DIR/issue-84973-blacklist.rs:17:13: 17:22]`
+   |     |
+   |     required by a bound introduced by this call
    |
    = note: consider using `Box::pin`
 note: required by a bound in `f_unpin`
diff --git a/src/test/ui/suggestions/issue-84973-negative.stderr b/src/test/ui/suggestions/issue-84973-negative.stderr
index 15559d4ae2c2f..ce838bce09e7b 100644
--- a/src/test/ui/suggestions/issue-84973-negative.stderr
+++ b/src/test/ui/suggestions/issue-84973-negative.stderr
@@ -17,7 +17,7 @@ error[E0277]: the trait bound `f32: Tr` is not satisfied
   --> $DIR/issue-84973-negative.rs:11:9
    |
 LL |     bar(b);
-   |     --- ^ expected an implementor of trait `Tr`
+   |     --- ^ the trait `Tr` is not implemented for `f32`
    |     |
    |     required by a bound introduced by this call
    |
diff --git a/src/test/ui/suggestions/issue-84973.stderr b/src/test/ui/suggestions/issue-84973.stderr
index 24c989ec3e86d..ae2bf5aac40b0 100644
--- a/src/test/ui/suggestions/issue-84973.stderr
+++ b/src/test/ui/suggestions/issue-84973.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `Fancy: SomeTrait` is not satisfied
   --> $DIR/issue-84973.rs:6:24
    |
 LL |     let o = Other::new(f);
-   |             ---------- ^ expected an implementor of trait `SomeTrait`
+   |             ---------- ^ the trait `SomeTrait` is not implemented for `Fancy`
    |             |
    |             required by a bound introduced by this call
    |
diff --git a/src/test/ui/suggestions/slice-issue-87994.stderr b/src/test/ui/suggestions/slice-issue-87994.stderr
index 44f0da27f1360..84ecd749b0dda 100644
--- a/src/test/ui/suggestions/slice-issue-87994.stderr
+++ b/src/test/ui/suggestions/slice-issue-87994.stderr
@@ -2,7 +2,7 @@ error[E0277]: the size for values of type `[i32]` cannot be known at compilation
   --> $DIR/slice-issue-87994.rs:3:12
    |
 LL |   for _ in v[1..] {
-   |            ^^^^^^ expected an implementor of trait `IntoIterator`
+   |            ^^^^^^ the trait `IntoIterator` is not implemented for `[i32]`
    |
    = note: the trait bound `[i32]: IntoIterator` is not satisfied
    = note: required for `[i32]` to implement `IntoIterator`
@@ -17,7 +17,7 @@ error[E0277]: `[i32]` is not an iterator
   --> $DIR/slice-issue-87994.rs:3:12
    |
 LL |   for _ in v[1..] {
-   |            ^^^^^^ expected an implementor of trait `IntoIterator`
+   |            ^^^^^^ the trait `IntoIterator` is not implemented for `[i32]`
    |
    = note: the trait bound `[i32]: IntoIterator` is not satisfied
    = note: required for `[i32]` to implement `IntoIterator`
@@ -32,7 +32,7 @@ error[E0277]: the size for values of type `[K]` cannot be known at compilation t
   --> $DIR/slice-issue-87994.rs:11:13
    |
 LL |   for i2 in v2[1..] {
-   |             ^^^^^^^ expected an implementor of trait `IntoIterator`
+   |             ^^^^^^^ the trait `IntoIterator` is not implemented for `[K]`
    |
    = note: the trait bound `[K]: IntoIterator` is not satisfied
    = note: required for `[K]` to implement `IntoIterator`
@@ -47,7 +47,7 @@ error[E0277]: `[K]` is not an iterator
   --> $DIR/slice-issue-87994.rs:11:13
    |
 LL |   for i2 in v2[1..] {
-   |             ^^^^^^^ expected an implementor of trait `IntoIterator`
+   |             ^^^^^^^ the trait `IntoIterator` is not implemented for `[K]`
    |
    = note: the trait bound `[K]: IntoIterator` is not satisfied
    = note: required for `[K]` to implement `IntoIterator`
diff --git a/src/test/ui/suggestions/suggest-adding-reference-to-trait-assoc-item.stderr b/src/test/ui/suggestions/suggest-adding-reference-to-trait-assoc-item.stderr
index b930d22a3915e..125a8b44f2f0a 100644
--- a/src/test/ui/suggestions/suggest-adding-reference-to-trait-assoc-item.stderr
+++ b/src/test/ui/suggestions/suggest-adding-reference-to-trait-assoc-item.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `&mut usize: Default` is not satisfied
   --> $DIR/suggest-adding-reference-to-trait-assoc-item.rs:13:9
    |
 LL |     foo(Default::default());
-   |         ^^^^^^^^^^^^^^^^ expected an implementor of trait `Default`
+   |         ^^^^^^^^^^^^^^^^ the trait `Default` is not implemented for `&mut usize`
    |
 help: consider mutably borrowing here
    |
@@ -13,7 +13,7 @@ error[E0277]: the trait bound `&usize: Default` is not satisfied
   --> $DIR/suggest-adding-reference-to-trait-assoc-item.rs:14:9
    |
 LL |     bar(Default::default());
-   |         ^^^^^^^^^^^^^^^^ expected an implementor of trait `Default`
+   |         ^^^^^^^^^^^^^^^^ the trait `Default` is not implemented for `&usize`
    |
 help: consider borrowing here
    |
diff --git a/src/test/ui/suggestions/suggest-borrow-to-dyn-object.stderr b/src/test/ui/suggestions/suggest-borrow-to-dyn-object.stderr
index 6b6e406130ec2..6ce9bfd9dcaa2 100644
--- a/src/test/ui/suggestions/suggest-borrow-to-dyn-object.stderr
+++ b/src/test/ui/suggestions/suggest-borrow-to-dyn-object.stderr
@@ -2,9 +2,7 @@ error[E0277]: the size for values of type `[u8]` cannot be known at compilation
   --> $DIR/suggest-borrow-to-dyn-object.rs:12:11
    |
 LL |     check(s);
-   |     ----- ^ doesn't have a size known at compile-time
-   |     |
-   |     required by a bound introduced by this call
+   |           ^ doesn't have a size known at compile-time
    |
    = help: within `OsStr`, the trait `Sized` is not implemented for `[u8]`
    = note: required because it appears within the type `OsStr`
diff --git a/src/test/ui/suggestions/suggest-imm-mut-trait-implementations.stderr b/src/test/ui/suggestions/suggest-imm-mut-trait-implementations.stderr
index 6583cabe18489..f2eb651eaa426 100644
--- a/src/test/ui/suggestions/suggest-imm-mut-trait-implementations.stderr
+++ b/src/test/ui/suggestions/suggest-imm-mut-trait-implementations.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `A: Trait` is not satisfied
   --> $DIR/suggest-imm-mut-trait-implementations.rs:20:9
    |
 LL |     foo(a);
-   |     --- ^ expected an implementor of trait `Trait`
+   |     --- ^ the trait `Trait` is not implemented for `A`
    |     |
    |     required by a bound introduced by this call
    |
@@ -22,7 +22,7 @@ error[E0277]: the trait bound `B: Trait` is not satisfied
   --> $DIR/suggest-imm-mut-trait-implementations.rs:21:9
    |
 LL |     foo(b);
-   |     --- ^ expected an implementor of trait `Trait`
+   |     --- ^ the trait `Trait` is not implemented for `B`
    |     |
    |     required by a bound introduced by this call
    |
@@ -40,7 +40,7 @@ error[E0277]: the trait bound `C: Trait` is not satisfied
   --> $DIR/suggest-imm-mut-trait-implementations.rs:22:9
    |
 LL |     foo(c);
-   |     --- ^ expected an implementor of trait `Trait`
+   |     --- ^ the trait `Trait` is not implemented for `C`
    |     |
    |     required by a bound introduced by this call
    |
diff --git a/src/test/ui/traits/associated_type_bound/check-trait-object-bounds-1.stderr b/src/test/ui/traits/associated_type_bound/check-trait-object-bounds-1.stderr
index bfbbe7fd25702..fa7a8a2a09335 100644
--- a/src/test/ui/traits/associated_type_bound/check-trait-object-bounds-1.stderr
+++ b/src/test/ui/traits/associated_type_bound/check-trait-object-bounds-1.stderr
@@ -1,8 +1,8 @@
 error[E0277]: the trait bound `str: Clone` is not satisfied
-  --> $DIR/check-trait-object-bounds-1.rs:12:5
+  --> $DIR/check-trait-object-bounds-1.rs:12:9
    |
 LL |     f::<dyn X<Y = str>>();
-   |     ^^^^^^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `str`
+   |         ^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `str`
    |
    = help: the trait `Clone` is implemented for `String`
 note: required by a bound in `f`
diff --git a/src/test/ui/traits/associated_type_bound/check-trait-object-bounds-2.stderr b/src/test/ui/traits/associated_type_bound/check-trait-object-bounds-2.stderr
index 46e8ce7887493..4084f69a6f04b 100644
--- a/src/test/ui/traits/associated_type_bound/check-trait-object-bounds-2.stderr
+++ b/src/test/ui/traits/associated_type_bound/check-trait-object-bounds-2.stderr
@@ -1,8 +1,8 @@
 error[E0277]: expected a `FnOnce<(&i32,)>` closure, found `i32`
-  --> $DIR/check-trait-object-bounds-2.rs:13:5
+  --> $DIR/check-trait-object-bounds-2.rs:13:9
    |
 LL |     f::<dyn for<'x> X<'x, F = i32>>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected an `FnOnce<(&i32,)>` closure, found `i32`
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^ expected an `FnOnce<(&i32,)>` closure, found `i32`
    |
    = help: the trait `for<'r> FnOnce<(&'r i32,)>` is not implemented for `i32`
 note: required by a bound in `f`
diff --git a/src/test/ui/traits/associated_type_bound/check-trait-object-bounds-4.stderr b/src/test/ui/traits/associated_type_bound/check-trait-object-bounds-4.stderr
index 3ca36d5d2ff19..4891ee9c29f7e 100644
--- a/src/test/ui/traits/associated_type_bound/check-trait-object-bounds-4.stderr
+++ b/src/test/ui/traits/associated_type_bound/check-trait-object-bounds-4.stderr
@@ -1,8 +1,8 @@
 error[E0277]: the trait bound `str: Clone` is not satisfied
-  --> $DIR/check-trait-object-bounds-4.rs:15:5
+  --> $DIR/check-trait-object-bounds-4.rs:15:9
    |
 LL |     f::<dyn X<Y = str>>();
-   |     ^^^^^^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `str`
+   |         ^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `str`
    |
    = help: the trait `Clone` is implemented for `String`
 note: required by a bound in `f`
diff --git a/src/test/ui/traits/bad-method-typaram-kind.stderr b/src/test/ui/traits/bad-method-typaram-kind.stderr
index 8befa4c5f738b..56acfbe80d03f 100644
--- a/src/test/ui/traits/bad-method-typaram-kind.stderr
+++ b/src/test/ui/traits/bad-method-typaram-kind.stderr
@@ -1,8 +1,8 @@
 error[E0277]: `T` cannot be sent between threads safely
-  --> $DIR/bad-method-typaram-kind.rs:2:7
+  --> $DIR/bad-method-typaram-kind.rs:2:13
    |
 LL |     1.bar::<T>();
-   |       ^^^ `T` cannot be sent between threads safely
+   |             ^ `T` cannot be sent between threads safely
    |
 note: required by a bound in `Bar::bar`
   --> $DIR/bad-method-typaram-kind.rs:6:14
diff --git a/src/test/ui/traits/bound/assoc-fn-bound-root-obligation.rs b/src/test/ui/traits/bound/assoc-fn-bound-root-obligation.rs
index 5ba189aa82a41..f9a9347641143 100644
--- a/src/test/ui/traits/bound/assoc-fn-bound-root-obligation.rs
+++ b/src/test/ui/traits/bound/assoc-fn-bound-root-obligation.rs
@@ -2,7 +2,6 @@ fn strip_lf(s: &str) -> &str {
     s.strip_suffix(b'\n').unwrap_or(s)
     //~^ ERROR expected a `FnMut<(char,)>` closure, found `u8`
     //~| NOTE expected an `FnMut<(char,)>` closure, found `u8`
-    //~| NOTE required by a bound introduced by this call
     //~| HELP the trait `FnMut<(char,)>` is not implemented for `u8`
     //~| HELP the following other types implement trait `Pattern<'a>`:
     //~| NOTE required for `u8` to implement `Pattern<'_>`
diff --git a/src/test/ui/traits/bound/assoc-fn-bound-root-obligation.stderr b/src/test/ui/traits/bound/assoc-fn-bound-root-obligation.stderr
index 41120c09fb164..ce9ab2d811ae1 100644
--- a/src/test/ui/traits/bound/assoc-fn-bound-root-obligation.stderr
+++ b/src/test/ui/traits/bound/assoc-fn-bound-root-obligation.stderr
@@ -1,10 +1,8 @@
 error[E0277]: expected a `FnMut<(char,)>` closure, found `u8`
-  --> $DIR/assoc-fn-bound-root-obligation.rs:2:20
+  --> $DIR/assoc-fn-bound-root-obligation.rs:2:7
    |
 LL |     s.strip_suffix(b'\n').unwrap_or(s)
-   |       ------------ ^^^^^ expected an `FnMut<(char,)>` closure, found `u8`
-   |       |
-   |       required by a bound introduced by this call
+   |       ^^^^^^^^^^^^ expected an `FnMut<(char,)>` closure, found `u8`
    |
    = help: the trait `FnMut<(char,)>` is not implemented for `u8`
    = help: the following other types implement trait `Pattern<'a>`:
diff --git a/src/test/ui/traits/bound/on-structs-and-enums-locals.rs b/src/test/ui/traits/bound/on-structs-and-enums-locals.rs
index 21c0ce80f8a8d..60ba343bb0a5c 100644
--- a/src/test/ui/traits/bound/on-structs-and-enums-locals.rs
+++ b/src/test/ui/traits/bound/on-structs-and-enums-locals.rs
@@ -8,8 +8,8 @@ struct Foo<T:Trait> {
 
 fn main() {
     let foo = Foo {
-    //~^ ERROR E0277
         x: 3
+    //~^ ERROR E0277
     };
 
     let baz: Foo<usize> = loop { };
diff --git a/src/test/ui/traits/bound/on-structs-and-enums-locals.stderr b/src/test/ui/traits/bound/on-structs-and-enums-locals.stderr
index c9068a270020d..20bbe69c059f8 100644
--- a/src/test/ui/traits/bound/on-structs-and-enums-locals.stderr
+++ b/src/test/ui/traits/bound/on-structs-and-enums-locals.stderr
@@ -11,10 +11,10 @@ LL | struct Foo<T:Trait> {
    |              ^^^^^ required by this bound in `Foo`
 
 error[E0277]: the trait bound `{integer}: Trait` is not satisfied
-  --> $DIR/on-structs-and-enums-locals.rs:10:15
+  --> $DIR/on-structs-and-enums-locals.rs:11:12
    |
-LL |     let foo = Foo {
-   |               ^^^ the trait `Trait` is not implemented for `{integer}`
+LL |         x: 3
+   |            ^ the trait `Trait` is not implemented for `{integer}`
    |
 note: required by a bound in `Foo`
   --> $DIR/on-structs-and-enums-locals.rs:5:14
diff --git a/src/test/ui/traits/bound/on-structs-and-enums-xc1.rs b/src/test/ui/traits/bound/on-structs-and-enums-xc1.rs
index 8156868e048d9..5ef35b513e0fb 100644
--- a/src/test/ui/traits/bound/on-structs-and-enums-xc1.rs
+++ b/src/test/ui/traits/bound/on-structs-and-enums-xc1.rs
@@ -6,8 +6,8 @@ use on_structs_and_enums_xc::{Bar, Foo, Trait};
 
 fn main() {
     let foo = Foo {
-    //~^ ERROR E0277
         x: 3
+    //~^ ERROR E0277
     };
     let bar: Bar<f64> = return;
     //~^ ERROR E0277
diff --git a/src/test/ui/traits/bound/on-structs-and-enums-xc1.stderr b/src/test/ui/traits/bound/on-structs-and-enums-xc1.stderr
index f4cc64af94f37..3fb5decb723ea 100644
--- a/src/test/ui/traits/bound/on-structs-and-enums-xc1.stderr
+++ b/src/test/ui/traits/bound/on-structs-and-enums-xc1.stderr
@@ -11,10 +11,10 @@ LL | pub enum Bar<T:Trait> {
    |                ^^^^^ required by this bound in `Bar`
 
 error[E0277]: the trait bound `{integer}: Trait` is not satisfied
-  --> $DIR/on-structs-and-enums-xc1.rs:8:15
+  --> $DIR/on-structs-and-enums-xc1.rs:9:12
    |
-LL |     let foo = Foo {
-   |               ^^^ the trait `Trait` is not implemented for `{integer}`
+LL |         x: 3
+   |            ^ the trait `Trait` is not implemented for `{integer}`
    |
 note: required by a bound in `Foo`
   --> $DIR/auxiliary/on_structs_and_enums_xc.rs:5:18
diff --git a/src/test/ui/traits/inheritance/repeated-supertrait-ambig.stderr b/src/test/ui/traits/inheritance/repeated-supertrait-ambig.stderr
index cab0ccdf710da..656e0d0bf2662 100644
--- a/src/test/ui/traits/inheritance/repeated-supertrait-ambig.stderr
+++ b/src/test/ui/traits/inheritance/repeated-supertrait-ambig.stderr
@@ -1,18 +1,22 @@
 error[E0277]: the trait bound `dyn CompareToInts: CompareTo<i32>` is not satisfied
-  --> $DIR/repeated-supertrait-ambig.rs:26:7
+  --> $DIR/repeated-supertrait-ambig.rs:26:15
    |
 LL |     c.same_as(22)
-   |       ^^^^^^^ the trait `CompareTo<i32>` is not implemented for `dyn CompareToInts`
+   |       ------- ^^ the trait `CompareTo<i32>` is not implemented for `dyn CompareToInts`
+   |       |
+   |       required by a bound introduced by this call
    |
    = help: the following other types implement trait `CompareTo<T>`:
              <i64 as CompareTo<i64>>
              <i64 as CompareTo<u64>>
 
 error[E0277]: the trait bound `C: CompareTo<i32>` is not satisfied
-  --> $DIR/repeated-supertrait-ambig.rs:30:7
+  --> $DIR/repeated-supertrait-ambig.rs:30:15
    |
 LL |     c.same_as(22)
-   |       ^^^^^^^ the trait `CompareTo<i32>` is not implemented for `C`
+   |       ------- ^^ the trait `CompareTo<i32>` is not implemented for `C`
+   |       |
+   |       required by a bound introduced by this call
    |
 help: consider further restricting this bound
    |
@@ -20,20 +24,24 @@ LL | fn with_trait<C:CompareToInts + CompareTo<i32>>(c: &C) -> bool {
    |                               ++++++++++++++++
 
 error[E0277]: the trait bound `dyn CompareToInts: CompareTo<i32>` is not satisfied
-  --> $DIR/repeated-supertrait-ambig.rs:34:5
+  --> $DIR/repeated-supertrait-ambig.rs:34:37
    |
 LL |     <dyn CompareToInts>::same_as(c, 22)
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `CompareTo<i32>` is not implemented for `dyn CompareToInts`
+   |     ----------------------------    ^^ the trait `CompareTo<i32>` is not implemented for `dyn CompareToInts`
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: the following other types implement trait `CompareTo<T>`:
              <i64 as CompareTo<i64>>
              <i64 as CompareTo<u64>>
 
 error[E0277]: the trait bound `C: CompareTo<i32>` is not satisfied
-  --> $DIR/repeated-supertrait-ambig.rs:38:5
+  --> $DIR/repeated-supertrait-ambig.rs:38:27
    |
 LL |     CompareTo::same_as(c, 22)
-   |     ^^^^^^^^^^^^^^^^^^ the trait `CompareTo<i32>` is not implemented for `C`
+   |     ------------------    ^^ the trait `CompareTo<i32>` is not implemented for `C`
+   |     |
+   |     required by a bound introduced by this call
    |
 help: consider further restricting this bound
    |
@@ -41,10 +49,12 @@ LL | fn with_ufcs2<C:CompareToInts + CompareTo<i32>>(c: &C) -> bool {
    |                               ++++++++++++++++
 
 error[E0277]: the trait bound `i64: CompareTo<i32>` is not satisfied
-  --> $DIR/repeated-supertrait-ambig.rs:42:23
+  --> $DIR/repeated-supertrait-ambig.rs:42:31
    |
 LL |     assert_eq!(22_i64.same_as(22), true);
-   |                       ^^^^^^^ the trait `CompareTo<i32>` is not implemented for `i64`
+   |                       ------- ^^ the trait `CompareTo<i32>` is not implemented for `i64`
+   |                       |
+   |                       required by a bound introduced by this call
    |
    = help: the following other types implement trait `CompareTo<T>`:
              <i64 as CompareTo<i64>>
diff --git a/src/test/ui/traits/issue-77982.stderr b/src/test/ui/traits/issue-77982.stderr
index 2b832e27c5224..e210f11b3e0c1 100644
--- a/src/test/ui/traits/issue-77982.stderr
+++ b/src/test/ui/traits/issue-77982.stderr
@@ -2,7 +2,9 @@ error[E0283]: type annotations needed
   --> $DIR/issue-77982.rs:8:10
    |
 LL |     opts.get(opt.as_ref());
-   |          ^^^ cannot infer type of the type parameter `Q` declared on the associated function `get`
+   |          ^^^ ------------ type must be known at this point
+   |          |
+   |          cannot infer type of the type parameter `Q` declared on the associated function `get`
    |
    = note: multiple `impl`s satisfying `String: Borrow<_>` found in the following crates: `alloc`, `core`:
            - impl Borrow<str> for String;
@@ -13,7 +15,7 @@ note: required by a bound in `HashMap::<K, V, S>::get`
    |
 LL |         K: Borrow<Q>,
    |            ^^^^^^^^^ required by this bound in `HashMap::<K, V, S>::get`
-help: consider specifying the type argument in the function call
+help: consider specifying the generic argument
    |
 LL |     opts.get::<Q>(opt.as_ref());
    |             +++++
@@ -42,7 +44,7 @@ error[E0283]: type annotations needed
 LL |     let ips: Vec<_> = (0..100_000).map(|_| u32::from(0u32.into())).collect();
    |                                            ---------      ^^^^
    |                                            |
-   |                                            type must be known at this point
+   |                                            required by a bound introduced by this call
    |
    = note: multiple `impl`s satisfying `u32: From<_>` found in the following crates: `core`, `std`:
            - impl From<Ipv4Addr> for u32;
diff --git a/src/test/ui/traits/issue-97576.stderr b/src/test/ui/traits/issue-97576.stderr
index 9062a0fab630a..146d38d076a3c 100644
--- a/src/test/ui/traits/issue-97576.stderr
+++ b/src/test/ui/traits/issue-97576.stderr
@@ -1,8 +1,10 @@
 error[E0277]: the trait bound `String: From<impl ToString>` is not satisfied
-  --> $DIR/issue-97576.rs:8:22
+  --> $DIR/issue-97576.rs:8:18
    |
 LL |             bar: bar.into(),
-   |                      ^^^^ the trait `From<impl ToString>` is not implemented for `String`
+   |                  ^^^ ---- required by a bound introduced by this call
+   |                  |
+   |                  the trait `From<impl ToString>` is not implemented for `String`
    |
    = note: required for `impl ToString` to implement `Into<String>`
 
diff --git a/src/test/ui/traits/multidispatch-convert-ambig-dest.stderr b/src/test/ui/traits/multidispatch-convert-ambig-dest.stderr
index cbec359342148..6e6172eea4746 100644
--- a/src/test/ui/traits/multidispatch-convert-ambig-dest.stderr
+++ b/src/test/ui/traits/multidispatch-convert-ambig-dest.stderr
@@ -13,7 +13,9 @@ error[E0283]: type annotations needed
   --> $DIR/multidispatch-convert-ambig-dest.rs:26:5
    |
 LL |     test(22, std::default::Default::default());
-   |     ^^^^ cannot infer type of the type parameter `U` declared on the function `test`
+   |     ^^^^     -------------------------------- type must be known at this point
+   |     |
+   |     cannot infer type of the type parameter `U` declared on the function `test`
    |
 note: multiple `impl`s satisfying `i32: Convert<_>` found
   --> $DIR/multidispatch-convert-ambig-dest.rs:8:1
@@ -30,10 +32,10 @@ LL | fn test<T,U>(_: T, _: U)
    |    ---- required by a bound in this
 LL | where T : Convert<U>
    |           ^^^^^^^^^^ required by this bound in `test`
-help: consider specifying the type arguments in the function call
+help: consider specifying the generic arguments
    |
-LL |     test::<T, U>(22, std::default::Default::default());
-   |         ++++++++
+LL |     test::<i32, U>(22, std::default::Default::default());
+   |         ++++++++++
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/traits/negative-impls/negated-auto-traits-error.stderr b/src/test/ui/traits/negative-impls/negated-auto-traits-error.stderr
index bf7c3bcc6aa9b..41fc3600fcd54 100644
--- a/src/test/ui/traits/negative-impls/negated-auto-traits-error.stderr
+++ b/src/test/ui/traits/negative-impls/negated-auto-traits-error.stderr
@@ -61,7 +61,7 @@ error[E0277]: `dummy2::TestType` cannot be sent between threads safely
   --> $DIR/negated-auto-traits-error.rs:48:13
    |
 LL |     is_send(Box::new(TestType));
-   |     ------- ^^^^^^^^^^^^^^^^^^ expected an implementor of trait `Send`
+   |     ------- ^^^^^^^^^^^^^^^^^^ the trait `Send` is not implemented for `Unique<dummy2::TestType>`
    |     |
    |     required by a bound introduced by this call
    |
diff --git a/src/test/ui/traits/suggest-where-clause.stderr b/src/test/ui/traits/suggest-where-clause.stderr
index d4d9b4967478a..747e2477b9cf1 100644
--- a/src/test/ui/traits/suggest-where-clause.stderr
+++ b/src/test/ui/traits/suggest-where-clause.stderr
@@ -19,13 +19,13 @@ LL + fn check<T: Iterator, U>() {
    |
 
 error[E0277]: the size for values of type `U` cannot be known at compilation time
-  --> $DIR/suggest-where-clause.rs:10:5
+  --> $DIR/suggest-where-clause.rs:10:20
    |
 LL | fn check<T: Iterator, U: ?Sized>() {
    |                       - this type parameter needs to be `std::marker::Sized`
 ...
 LL |     mem::size_of::<Misc<U>>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
+   |                    ^^^^^^^ doesn't have a size known at compile-time
    |
 note: required because it appears within the type `Misc<U>`
   --> $DIR/suggest-where-clause.rs:3:8
diff --git a/src/test/ui/transmutability/references.stderr b/src/test/ui/transmutability/references.stderr
index b1359ea586583..17ffcf64177e3 100644
--- a/src/test/ui/transmutability/references.stderr
+++ b/src/test/ui/transmutability/references.stderr
@@ -1,8 +1,8 @@
 error[E0277]: `&'static Unit` cannot be safely transmuted into `&'static Unit` in the defining scope of `assert::Context`.
-  --> $DIR/references.rs:19:37
+  --> $DIR/references.rs:19:52
    |
 LL |     assert::is_maybe_transmutable::<&'static Unit, &'static Unit>();
-   |                                     ^^^^^^^^^^^^^ `&'static Unit` cannot be safely transmuted into `&'static Unit` in the defining scope of `assert::Context`.
+   |                                                    ^^^^^^^^^^^^^ `&'static Unit` cannot be safely transmuted into `&'static Unit` in the defining scope of `assert::Context`.
    |
    = help: the trait `BikeshedIntrinsicFrom<&'static Unit, assert::Context, true, true, true, true>` is not implemented for `&'static Unit`
 note: required by a bound in `is_maybe_transmutable`
diff --git a/src/test/ui/type/type-params-in-different-spaces-2.stderr b/src/test/ui/type/type-params-in-different-spaces-2.stderr
index 53610985f31da..220b3929c8857 100644
--- a/src/test/ui/type/type-params-in-different-spaces-2.stderr
+++ b/src/test/ui/type/type-params-in-different-spaces-2.stderr
@@ -1,8 +1,10 @@
 error[E0277]: the trait bound `Self: Tr<U>` is not satisfied
-  --> $DIR/type-params-in-different-spaces-2.rs:10:9
+  --> $DIR/type-params-in-different-spaces-2.rs:10:16
    |
 LL |         Tr::op(u)
-   |         ^^^^^^ the trait `Tr<U>` is not implemented for `Self`
+   |         ------ ^ the trait `Tr<U>` is not implemented for `Self`
+   |         |
+   |         required by a bound introduced by this call
    |
 help: consider further restricting `Self`
    |
@@ -10,10 +12,12 @@ LL |     fn test<U>(u: U) -> Self where Self: Tr<U> {
    |                              +++++++++++++++++
 
 error[E0277]: the trait bound `Self: Tr<U>` is not satisfied
-  --> $DIR/type-params-in-different-spaces-2.rs:16:9
+  --> $DIR/type-params-in-different-spaces-2.rs:16:16
    |
 LL |         Tr::op(u)
-   |         ^^^^^^ the trait `Tr<U>` is not implemented for `Self`
+   |         ------ ^ the trait `Tr<U>` is not implemented for `Self`
+   |         |
+   |         required by a bound introduced by this call
    |
 help: consider further restricting `Self`
    |
diff --git a/src/test/ui/typeck/typeck-default-trait-impl-negation-sync.stderr b/src/test/ui/typeck/typeck-default-trait-impl-negation-sync.stderr
index 6bb5e1f54272b..b9fca1a1b54b8 100644
--- a/src/test/ui/typeck/typeck-default-trait-impl-negation-sync.stderr
+++ b/src/test/ui/typeck/typeck-default-trait-impl-negation-sync.stderr
@@ -12,10 +12,10 @@ LL | fn is_sync<T: Sync>() {}
    |               ^^^^ required by this bound in `is_sync`
 
 error[E0277]: `UnsafeCell<u8>` cannot be shared between threads safely
-  --> $DIR/typeck-default-trait-impl-negation-sync.rs:36:5
+  --> $DIR/typeck-default-trait-impl-negation-sync.rs:36:15
    |
 LL |     is_sync::<MyTypeWUnsafe>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^ `UnsafeCell<u8>` cannot be shared between threads safely
+   |               ^^^^^^^^^^^^^ `UnsafeCell<u8>` cannot be shared between threads safely
    |
    = help: within `MyTypeWUnsafe`, the trait `Sync` is not implemented for `UnsafeCell<u8>`
 note: required because it appears within the type `MyTypeWUnsafe`
@@ -30,10 +30,10 @@ LL | fn is_sync<T: Sync>() {}
    |               ^^^^ required by this bound in `is_sync`
 
 error[E0277]: `Managed` cannot be shared between threads safely
-  --> $DIR/typeck-default-trait-impl-negation-sync.rs:39:5
+  --> $DIR/typeck-default-trait-impl-negation-sync.rs:39:15
    |
 LL |     is_sync::<MyTypeManaged>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^ `Managed` cannot be shared between threads safely
+   |               ^^^^^^^^^^^^^ `Managed` cannot be shared between threads safely
    |
    = help: within `MyTypeManaged`, the trait `Sync` is not implemented for `Managed`
 note: required because it appears within the type `MyTypeManaged`
diff --git a/src/test/ui/ufcs/ufcs-qpath-self-mismatch.stderr b/src/test/ui/ufcs/ufcs-qpath-self-mismatch.stderr
index c6f9b3661a232..f08c81bc1e937 100644
--- a/src/test/ui/ufcs/ufcs-qpath-self-mismatch.stderr
+++ b/src/test/ui/ufcs/ufcs-qpath-self-mismatch.stderr
@@ -1,8 +1,10 @@
 error[E0277]: cannot add `u32` to `i32`
-  --> $DIR/ufcs-qpath-self-mismatch.rs:4:5
+  --> $DIR/ufcs-qpath-self-mismatch.rs:4:31
    |
 LL |     <i32 as Add<u32>>::add(1, 2);
-   |     ^^^^^^^^^^^^^^^^^^^^^^ no implementation for `i32 + u32`
+   |     ----------------------    ^ no implementation for `i32 + u32`
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: the trait `Add<u32>` is not implemented for `i32`
    = help: the following other types implement trait `Add<Rhs>`:
diff --git a/src/test/ui/unboxed-closures/unboxed-closures-infer-fn-once-move-from-projection.stderr b/src/test/ui/unboxed-closures/unboxed-closures-infer-fn-once-move-from-projection.stderr
index 85ff49d61a3ff..635ebbb71d070 100644
--- a/src/test/ui/unboxed-closures/unboxed-closures-infer-fn-once-move-from-projection.stderr
+++ b/src/test/ui/unboxed-closures/unboxed-closures-infer-fn-once-move-from-projection.stderr
@@ -6,7 +6,17 @@ LL |     let c = || drop(y.0);
    |             |
    |             this closure implements `FnOnce`, not `Fn`
 LL |     foo(c);
-   |     --- the requirement to implement `Fn` derives from here
+   |     --- - the requirement to implement `Fn` derives from here
+   |     |
+   |     required by a bound introduced by this call
+   |
+note: required by a bound in `foo`
+  --> $DIR/unboxed-closures-infer-fn-once-move-from-projection.rs:4:14
+   |
+LL | fn foo<F>(f: F)
+   |    --- required by a bound in this
+LL |     where F: Fn()
+   |              ^^^^ required by this bound in `foo`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/union/union-generic.mirunsafeck.stderr b/src/test/ui/union/union-generic.mirunsafeck.stderr
index a4f0c400d7310..037022a91fcd0 100644
--- a/src/test/ui/union/union-generic.mirunsafeck.stderr
+++ b/src/test/ui/union/union-generic.mirunsafeck.stderr
@@ -11,10 +11,10 @@ LL | union U<T: Copy> {
    |            ^^^^ required by this bound in `U`
 
 error[E0277]: the trait bound `Rc<u32>: Copy` is not satisfied
-  --> $DIR/union-generic.rs:13:13
+  --> $DIR/union-generic.rs:13:17
    |
 LL |     let u = U::<Rc<u32>> { a: Default::default() };
-   |             ^^^^^^^^^^^^ the trait `Copy` is not implemented for `Rc<u32>`
+   |                 ^^^^^^^ the trait `Copy` is not implemented for `Rc<u32>`
    |
 note: required by a bound in `U`
   --> $DIR/union-generic.rs:6:12
diff --git a/src/test/ui/union/union-generic.thirunsafeck.stderr b/src/test/ui/union/union-generic.thirunsafeck.stderr
index a4f0c400d7310..037022a91fcd0 100644
--- a/src/test/ui/union/union-generic.thirunsafeck.stderr
+++ b/src/test/ui/union/union-generic.thirunsafeck.stderr
@@ -11,10 +11,10 @@ LL | union U<T: Copy> {
    |            ^^^^ required by this bound in `U`
 
 error[E0277]: the trait bound `Rc<u32>: Copy` is not satisfied
-  --> $DIR/union-generic.rs:13:13
+  --> $DIR/union-generic.rs:13:17
    |
 LL |     let u = U::<Rc<u32>> { a: Default::default() };
-   |             ^^^^^^^^^^^^ the trait `Copy` is not implemented for `Rc<u32>`
+   |                 ^^^^^^^ the trait `Copy` is not implemented for `Rc<u32>`
    |
 note: required by a bound in `U`
   --> $DIR/union-generic.rs:6:12
diff --git a/src/test/ui/unsized-locals/unsized-exprs.stderr b/src/test/ui/unsized-locals/unsized-exprs.stderr
index 6960255d98797..a7f57e3fd1566 100644
--- a/src/test/ui/unsized-locals/unsized-exprs.stderr
+++ b/src/test/ui/unsized-locals/unsized-exprs.stderr
@@ -12,9 +12,7 @@ error[E0277]: the size for values of type `[u8]` cannot be known at compilation
   --> $DIR/unsized-exprs.rs:24:22
    |
 LL |     udrop::<A<[u8]>>(A { 0: *foo() });
-   |     ---------------- ^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
-   |     |
-   |     required by a bound introduced by this call
+   |                      ^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
    = help: within `A<[u8]>`, the trait `Sized` is not implemented for `[u8]`
 note: required because it appears within the type `A<[u8]>`
diff --git a/src/test/ui/unsized/issue-30355.stderr b/src/test/ui/unsized/issue-30355.stderr
index d7af558eef42a..f5491552a45d2 100644
--- a/src/test/ui/unsized/issue-30355.stderr
+++ b/src/test/ui/unsized/issue-30355.stderr
@@ -2,9 +2,7 @@ error[E0277]: the size for values of type `[u8]` cannot be known at compilation
   --> $DIR/issue-30355.rs:5:8
    |
 LL |     &X(*Y)
-   |      - ^^ doesn't have a size known at compile-time
-   |      |
-   |      required by a bound introduced by this call
+   |        ^^ doesn't have a size known at compile-time
    |
    = help: the trait `Sized` is not implemented for `[u8]`
    = help: unsized fn params are gated as an unstable feature
diff --git a/src/test/ui/unsized/issue-71659.stderr b/src/test/ui/unsized/issue-71659.stderr
index d7b95f55769fd..50060e53a49d6 100644
--- a/src/test/ui/unsized/issue-71659.stderr
+++ b/src/test/ui/unsized/issue-71659.stderr
@@ -1,8 +1,10 @@
 error[E0277]: the trait bound `dyn Foo: CastTo<[i32]>` is not satisfied
-  --> $DIR/issue-71659.rs:30:15
+  --> $DIR/issue-71659.rs:30:13
    |
 LL |     let x = x.cast::<[i32]>();
-   |               ^^^^ the trait `CastTo<[i32]>` is not implemented for `dyn Foo`
+   |             ^ ---- required by a bound introduced by this call
+   |             |
+   |             the trait `CastTo<[i32]>` is not implemented for `dyn Foo`
    |
 note: required by a bound in `Cast::cast`
   --> $DIR/issue-71659.rs:19:15
diff --git a/src/test/ui/unsized/issue-75707.stderr b/src/test/ui/unsized/issue-75707.stderr
index 7d0a2cb85b612..97618ed05ed38 100644
--- a/src/test/ui/unsized/issue-75707.stderr
+++ b/src/test/ui/unsized/issue-75707.stderr
@@ -1,8 +1,8 @@
 error[E0277]: the trait bound `MyCall: Callback` is not satisfied
-  --> $DIR/issue-75707.rs:15:5
+  --> $DIR/issue-75707.rs:15:9
    |
 LL |     f::<dyn Processing<Call = MyCall>>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Callback` is not implemented for `MyCall`
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Callback` is not implemented for `MyCall`
    |
 note: required by a bound in `f`
   --> $DIR/issue-75707.rs:9:9
diff --git a/src/test/ui/unsized/unsized-fn-param.stderr b/src/test/ui/unsized/unsized-fn-param.stderr
index 0221ef16b4965..b477260543258 100644
--- a/src/test/ui/unsized/unsized-fn-param.stderr
+++ b/src/test/ui/unsized/unsized-fn-param.stderr
@@ -2,9 +2,7 @@ error[E0277]: the size for values of type `str` cannot be known at compilation t
   --> $DIR/unsized-fn-param.rs:11:11
    |
 LL |     foo11("bar", &"baz");
-   |     ----- ^^^^^ doesn't have a size known at compile-time
-   |     |
-   |     required by a bound introduced by this call
+   |           ^^^^^ doesn't have a size known at compile-time
    |
    = help: the trait `Sized` is not implemented for `str`
    = note: required for the cast from `str` to the object type `dyn AsRef<Path>`
@@ -17,9 +15,7 @@ error[E0277]: the size for values of type `str` cannot be known at compilation t
   --> $DIR/unsized-fn-param.rs:13:19
    |
 LL |     foo12(&"bar", "baz");
-   |     -----         ^^^^^ doesn't have a size known at compile-time
-   |     |
-   |     required by a bound introduced by this call
+   |                   ^^^^^ doesn't have a size known at compile-time
    |
    = help: the trait `Sized` is not implemented for `str`
    = note: required for the cast from `str` to the object type `dyn AsRef<Path>`
@@ -32,9 +28,7 @@ error[E0277]: the size for values of type `str` cannot be known at compilation t
   --> $DIR/unsized-fn-param.rs:16:11
    |
 LL |     foo21("bar", &"baz");
-   |     ----- ^^^^^ doesn't have a size known at compile-time
-   |     |
-   |     required by a bound introduced by this call
+   |           ^^^^^ doesn't have a size known at compile-time
    |
    = help: the trait `Sized` is not implemented for `str`
    = note: required for the cast from `str` to the object type `dyn AsRef<str>`
@@ -47,9 +41,7 @@ error[E0277]: the size for values of type `str` cannot be known at compilation t
   --> $DIR/unsized-fn-param.rs:18:19
    |
 LL |     foo22(&"bar", "baz");
-   |     -----         ^^^^^ doesn't have a size known at compile-time
-   |     |
-   |     required by a bound introduced by this call
+   |                   ^^^^^ doesn't have a size known at compile-time
    |
    = help: the trait `Sized` is not implemented for `str`
    = note: required for the cast from `str` to the object type `dyn AsRef<str>`
diff --git a/src/test/ui/unsized/unsized-struct.stderr b/src/test/ui/unsized/unsized-struct.stderr
index c9510e92fecb4..dff1b0a5112a4 100644
--- a/src/test/ui/unsized/unsized-struct.stderr
+++ b/src/test/ui/unsized/unsized-struct.stderr
@@ -25,10 +25,10 @@ LL + fn foo2<T>() { not_sized::<Foo<T>>() }
    |
 
 error[E0277]: the size for values of type `T` cannot be known at compilation time
-  --> $DIR/unsized-struct.rs:13:24
+  --> $DIR/unsized-struct.rs:13:35
    |
 LL | fn bar2<T: ?Sized>() { is_sized::<Bar<T>>() }
-   |         -              ^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
+   |         -                         ^^^^^^ doesn't have a size known at compile-time
    |         |
    |         this type parameter needs to be `std::marker::Sized`
    |
diff --git a/src/test/ui/unsized/unsized3.stderr b/src/test/ui/unsized/unsized3.stderr
index d64091b15eb1f..9ad1ac6b4df61 100644
--- a/src/test/ui/unsized/unsized3.stderr
+++ b/src/test/ui/unsized/unsized3.stderr
@@ -79,14 +79,12 @@ LL | fn f5<Y: ?Sized>(x: &Y) {}
    |        ++++++++
 
 error[E0277]: the size for values of type `X` cannot be known at compilation time
-  --> $DIR/unsized3.rs:40:8
+  --> $DIR/unsized3.rs:40:5
    |
 LL | fn f9<X: ?Sized>(x1: Box<S<X>>) {
    |       - this type parameter needs to be `std::marker::Sized`
 LL |     f5(&(*x1, 34));
-   |     -- ^^^^^^^^^^ doesn't have a size known at compile-time
-   |     |
-   |     required by a bound introduced by this call
+   |     ^^ doesn't have a size known at compile-time
    |
 note: required because it appears within the type `S<X>`
   --> $DIR/unsized3.rs:28:8
@@ -106,9 +104,7 @@ error[E0277]: the size for values of type `X` cannot be known at compilation tim
 LL | fn f10<X: ?Sized>(x1: Box<S<X>>) {
    |        - this type parameter needs to be `std::marker::Sized`
 LL |     f5(&(32, *x1));
-   |     --  ^^^^^^^^^ doesn't have a size known at compile-time
-   |     |
-   |     required by a bound introduced by this call
+   |         ^^^^^^^^^ doesn't have a size known at compile-time
    |
 note: required because it appears within the type `S<X>`
   --> $DIR/unsized3.rs:28:8
diff --git a/src/test/ui/where-clauses/where-clause-method-substituion.stderr b/src/test/ui/where-clauses/where-clause-method-substituion.stderr
index f431deee73f9a..8c47ed6d4317a 100644
--- a/src/test/ui/where-clauses/where-clause-method-substituion.stderr
+++ b/src/test/ui/where-clauses/where-clause-method-substituion.stderr
@@ -1,8 +1,8 @@
 error[E0277]: the trait bound `X: Foo<X>` is not satisfied
-  --> $DIR/where-clause-method-substituion.rs:20:7
+  --> $DIR/where-clause-method-substituion.rs:20:16
    |
 LL |     1.method::<X>();
-   |       ^^^^^^ the trait `Foo<X>` is not implemented for `X`
+   |                ^ the trait `Foo<X>` is not implemented for `X`
    |
 note: required by a bound in `Bar::method`
   --> $DIR/where-clause-method-substituion.rs:6:34
diff --git a/src/test/ui/where-clauses/where-clauses-method-unsatisfied.stderr b/src/test/ui/where-clauses/where-clauses-method-unsatisfied.stderr
index c13552bc26eee..e90502977ff6a 100644
--- a/src/test/ui/where-clauses/where-clauses-method-unsatisfied.stderr
+++ b/src/test/ui/where-clauses/where-clauses-method-unsatisfied.stderr
@@ -1,10 +1,8 @@
 error[E0277]: the trait bound `Bar: Eq` is not satisfied
-  --> $DIR/where-clauses-method-unsatisfied.rs:18:14
+  --> $DIR/where-clauses-method-unsatisfied.rs:18:7
    |
 LL |     x.equals(&x);
-   |       ------ ^^ the trait `Eq` is not implemented for `Bar`
-   |       |
-   |       required by a bound introduced by this call
+   |       ^^^^^^ the trait `Eq` is not implemented for `Bar`
    |
 note: required by a bound in `Foo::<T>::equals`
   --> $DIR/where-clauses-method-unsatisfied.rs:11:52
diff --git a/src/tools/rustfmt/src/attr.rs b/src/tools/rustfmt/src/attr.rs
index 41ba9a847e67a..f5c1ee5fdd121 100644
--- a/src/tools/rustfmt/src/attr.rs
+++ b/src/tools/rustfmt/src/attr.rs
@@ -49,10 +49,7 @@ pub(crate) fn get_span_without_attrs(stmt: &ast::Stmt) -> Span {
 }
 
 /// Returns attributes that are within `outer_span`.
-pub(crate) fn filter_inline_attrs(
-    attrs: &[ast::Attribute],
-    outer_span: Span,
-) -> Vec<ast::Attribute> {
+pub(crate) fn filter_inline_attrs(attrs: &[ast::Attribute], outer_span: Span) -> ast::AttrVec {
     attrs
         .iter()
         .filter(|a| outer_span.lo() <= a.span.lo() && a.span.hi() <= outer_span.hi())
diff --git a/src/tools/rustfmt/src/imports.rs b/src/tools/rustfmt/src/imports.rs
index 8d41c881589e5..b6530c69243ed 100644
--- a/src/tools/rustfmt/src/imports.rs
+++ b/src/tools/rustfmt/src/imports.rs
@@ -116,7 +116,7 @@ pub(crate) struct UseTree {
     // Additional fields for top level use items.
     // Should we have another struct for top-level use items rather than reusing this?
     visibility: Option<ast::Visibility>,
-    attrs: Option<Vec<ast::Attribute>>,
+    attrs: Option<ast::AttrVec>,
 }
 
 impl PartialEq for UseTree {
@@ -417,7 +417,7 @@ impl UseTree {
         list_item: Option<ListItem>,
         visibility: Option<ast::Visibility>,
         opt_lo: Option<BytePos>,
-        attrs: Option<Vec<ast::Attribute>>,
+        attrs: Option<ast::AttrVec>,
     ) -> UseTree {
         let span = if let Some(lo) = opt_lo {
             mk_sp(lo, a.span.hi())
diff --git a/src/tools/rustfmt/src/modules.rs b/src/tools/rustfmt/src/modules.rs
index 81da724329f02..7a0d1736c59a6 100644
--- a/src/tools/rustfmt/src/modules.rs
+++ b/src/tools/rustfmt/src/modules.rs
@@ -26,7 +26,7 @@ type FileModMap<'ast> = BTreeMap<FileName, Module<'ast>>;
 pub(crate) struct Module<'a> {
     ast_mod_kind: Option<Cow<'a, ast::ModKind>>,
     pub(crate) items: Cow<'a, Vec<rustc_ast::ptr::P<ast::Item>>>,
-    inner_attr: Vec<ast::Attribute>,
+    inner_attr: ast::AttrVec,
     pub(crate) span: Span,
 }
 
@@ -35,7 +35,7 @@ impl<'a> Module<'a> {
         mod_span: Span,
         ast_mod_kind: Option<Cow<'a, ast::ModKind>>,
         mod_items: Cow<'a, Vec<rustc_ast::ptr::P<ast::Item>>>,
-        mod_attrs: Cow<'a, Vec<ast::Attribute>>,
+        mod_attrs: Cow<'a, ast::AttrVec>,
     ) -> Self {
         let inner_attr = mod_attrs
             .iter()
@@ -158,7 +158,7 @@ impl<'ast, 'sess, 'c> ModResolver<'ast, 'sess> {
                         module_item.item.span,
                         Some(Cow::Owned(sub_mod_kind.clone())),
                         Cow::Owned(vec![]),
-                        Cow::Owned(vec![]),
+                        Cow::Owned(ast::AttrVec::new()),
                     ),
                 )?;
             }
@@ -185,7 +185,7 @@ impl<'ast, 'sess, 'c> ModResolver<'ast, 'sess> {
                         span,
                         Some(Cow::Owned(sub_mod_kind.clone())),
                         Cow::Owned(vec![]),
-                        Cow::Owned(vec![]),
+                        Cow::Owned(ast::AttrVec::new()),
                     ),
                 )?;
             }
diff --git a/src/tools/rustfmt/src/parse/parser.rs b/src/tools/rustfmt/src/parse/parser.rs
index 268c72649a65a..e0bd065518b3d 100644
--- a/src/tools/rustfmt/src/parse/parser.rs
+++ b/src/tools/rustfmt/src/parse/parser.rs
@@ -109,7 +109,7 @@ impl<'a> Parser<'a> {
         sess: &'a ParseSess,
         path: &Path,
         span: Span,
-    ) -> Result<(Vec<ast::Attribute>, Vec<ptr::P<ast::Item>>, Span), ParserError> {
+    ) -> Result<(ast::AttrVec, Vec<ptr::P<ast::Item>>, Span), ParserError> {
         let result = catch_unwind(AssertUnwindSafe(|| {
             let mut parser = new_parser_from_file(sess.inner(), path, Some(span));
             match parser.parse_mod(&TokenKind::Eof) {
diff --git a/src/tools/tidy/src/style.rs b/src/tools/tidy/src/style.rs
index 3cf44a2d7d1ef..dee58ff2fb510 100644
--- a/src/tools/tidy/src/style.rs
+++ b/src/tools/tidy/src/style.rs
@@ -125,16 +125,13 @@ fn should_ignore(line: &str) -> bool {
 
 /// Returns `true` if `line` is allowed to be longer than the normal limit.
 fn long_line_is_ok(extension: &str, is_error_code: bool, max_columns: usize, line: &str) -> bool {
-    if extension != "md" || is_error_code {
-        if line_is_url(is_error_code, max_columns, line) || should_ignore(line) {
-            return true;
-        }
-    } else if extension == "md" {
+    match extension {
+        // fluent files are allowed to be any length
+        "ftl" => true,
         // non-error code markdown is allowed to be any length
-        return true;
+        "md" if !is_error_code => true,
+        _ => line_is_url(is_error_code, max_columns, line) || should_ignore(line),
     }
-
-    false
 }
 
 enum Directive {
@@ -230,7 +227,7 @@ pub fn check(path: &Path, bad: &mut bool) {
     super::walk(path, &mut skip, &mut |entry, contents| {
         let file = entry.path();
         let filename = file.file_name().unwrap().to_string_lossy();
-        let extensions = [".rs", ".py", ".js", ".sh", ".c", ".cpp", ".h", ".md", ".css"];
+        let extensions = [".rs", ".py", ".js", ".sh", ".c", ".cpp", ".h", ".md", ".css", ".ftl"];
         if extensions.iter().all(|e| !filename.ends_with(e)) || filename.starts_with(".#") {
             return;
         }

From ac4ccebb24995bf73a8c5ebeb7eec05d460f4908 Mon Sep 17 00:00:00 2001
From: AndyJado <101876416+AndyJado@users.noreply.github.com>
Date: Mon, 22 Aug 2022 16:01:53 +0800
Subject: [PATCH 05/10] tidy up spaces in .ftl

---
 compiler/rustc_error_messages/locales/en-US/borrowck.ftl | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/compiler/rustc_error_messages/locales/en-US/borrowck.ftl b/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
index d89053a99d277..6032e65a57d27 100644
--- a/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
+++ b/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
@@ -51,5 +51,4 @@ borrowck_returned_lifetime_wrong =
     {$mir_def_name} was supposed to return data with lifetime `{$outlived_fr_name}` but it is returning data with lifetime `{$fr_name}`
 
 borrowck_returned_lifetime_short =
-    {$category_desc}requires that `{$free_region_name}` must outlive `{$outlived_fr_name}`"
-
+    {$category_desc}requires that `{$free_region_name}` must outlive `{$outlived_fr_name}`

From 8edf4599335b1fdfb6b4c616c91ca55792ef33ea Mon Sep 17 00:00:00 2001
From: AndyJado <101876416+AndyJado@users.noreply.github.com>
Date: Mon, 22 Aug 2022 18:10:28 +0800
Subject: [PATCH 06/10] `err.subdiag` on `MultiSpan`

---
 .../rustc_borrowck/src/diagnostics/region_errors.rs    |  4 ++--
 compiler/rustc_borrowck/src/session_diagnostics.rs     | 10 ++++++++++
 .../rustc_error_messages/locales/en-US/borrowck.ftl    |  3 +++
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
index 6894ec7956cfe..4f730262e0eb9 100644
--- a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
@@ -27,7 +27,7 @@ use rustc_span::Span;
 use crate::borrowck_errors;
 use crate::session_diagnostics::{
     FnMutError, FnMutReturnTypeErr, GenericDoesNotLiveLongEnough, LifeTimeOutLiveErr,
-    LifeTimeReturnCategoryErr,
+    LifeTimeReturnCategoryErr, RequireStaticErr,
 };
 
 use super::{OutlivesSuggestionBuilder, RegionName};
@@ -854,7 +854,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                     ident.span,
                     "calling this method introduces the `impl`'s 'static` requirement",
                 );
-                err.span_note(multi_span, "the used `impl` has a `'static` requirement");
+                err.subdiagnostic(RequireStaticErr::UsedImpl { multi_span });
                 err.span_suggestion_verbose(
                     span.shrink_to_hi(),
                     "consider relaxing the implicit `'static` requirement",
diff --git a/compiler/rustc_borrowck/src/session_diagnostics.rs b/compiler/rustc_borrowck/src/session_diagnostics.rs
index ff2196760039c..8c78c8589b8aa 100644
--- a/compiler/rustc_borrowck/src/session_diagnostics.rs
+++ b/compiler/rustc_borrowck/src/session_diagnostics.rs
@@ -1,3 +1,4 @@
+use rustc_errors::MultiSpan;
 use rustc_macros::{LintDiagnostic, SessionDiagnostic, SessionSubdiagnostic};
 use rustc_middle::ty::Ty;
 use rustc_span::Span;
@@ -122,3 +123,12 @@ pub(crate) enum LifeTimeReturnCategoryErr {
         outlived_fr_name: String,
     },
 }
+
+#[derive(SessionSubdiagnostic)]
+pub(crate) enum RequireStaticErr {
+    #[note(borrowck::used_impl_require_static)]
+    UsedImpl {
+        #[primary_span]
+        multi_span: MultiSpan,
+    },
+}
diff --git a/compiler/rustc_error_messages/locales/en-US/borrowck.ftl b/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
index 6032e65a57d27..94fd9b89d3544 100644
--- a/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
+++ b/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
@@ -52,3 +52,6 @@ borrowck_returned_lifetime_wrong =
 
 borrowck_returned_lifetime_short =
     {$category_desc}requires that `{$free_region_name}` must outlive `{$outlived_fr_name}`
+
+borrowck_used_impl_require_static =
+    the used `impl` has a `'static` requirement

From c5d4efd2948ea67705e90dfb609a31563dd680de Mon Sep 17 00:00:00 2001
From: AndyJado <101876416+AndyJado@users.noreply.github.com>
Date: Mon, 22 Aug 2022 18:39:01 +0800
Subject: [PATCH 07/10] fix typo : ""

---
 compiler/rustc_error_messages/locales/en-US/borrowck.ftl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/compiler/rustc_error_messages/locales/en-US/borrowck.ftl b/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
index 94fd9b89d3544..5da1f59168a6d 100644
--- a/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
+++ b/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
@@ -31,7 +31,7 @@ borrowck_var_cannot_escape_closure =
     captured variable cannot escape `FnMut` closure body
     .upvar_def = variable defined here
     .upvar = variable captured here
-    .fr =  "inferred to be a `FnMut` closure"
+    .fr =  inferred to be a `FnMut` closure
     .note = `FnMut` closures only have access to their captured variables while they are executing...
     .cannot_escape = ...therefore, they cannot allow references to captured variables to escape
 

From 408689db7c73cbd39c57595572c52ca96ad8f542 Mon Sep 17 00:00:00 2001
From: AndyJado <101876416+AndyJado@users.noreply.github.com>
Date: Mon, 22 Aug 2022 20:21:15 +0800
Subject: [PATCH 08/10] fix ui

---
 .../src/diagnostics/region_errors.rs          | 26 ++++++++++---------
 compiler/rustc_borrowck/src/lib.rs            |  3 ++-
 .../rustc_borrowck/src/session_diagnostics.rs | 12 ++++++++-
 .../locales/en-US/borrowck.ftl                | 20 +++++++++-----
 4 files changed, 41 insertions(+), 20 deletions(-)

diff --git a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
index 6894ec7956cfe..66b036d194af9 100644
--- a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
@@ -27,7 +27,7 @@ use rustc_span::Span;
 use crate::borrowck_errors;
 use crate::session_diagnostics::{
     FnMutError, FnMutReturnTypeErr, GenericDoesNotLiveLongEnough, LifeTimeOutLiveErr,
-    LifeTimeReturnCategoryErr,
+    LifeTimeReturnCategoryErr, RequireStaticErr,
 };
 
 use super::{OutlivesSuggestionBuilder, RegionName};
@@ -500,17 +500,17 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
 
         debug!("report_fnmut_error: output_ty={:?}", output_ty);
 
-        let ty_err = match output_ty.kind() {
-            ty::Closure(_, _) => FnMutReturnTypeErr::ReturnClosure { span: *span },
-            ty::Adt(def, _) if self.infcx.tcx.is_diagnostic_item(sym::gen_future, def.did()) => {
-                FnMutReturnTypeErr::ReturnAsyncBlock { span: *span }
-            }
-            _ => FnMutReturnTypeErr::ReturnRef { span: *span },
-        };
-
         let mut err = FnMutError {
             span: *span,
-            ty_err,
+            ty_err: match output_ty.kind() {
+                ty::Closure(_, _) => FnMutReturnTypeErr::ReturnClosure { span: *span },
+                ty::Adt(def, _)
+                    if self.infcx.tcx.is_diagnostic_item(sym::gen_future, def.did()) =>
+                {
+                    FnMutReturnTypeErr::ReturnAsyncBlock { span: *span }
+                }
+                _ => FnMutReturnTypeErr::ReturnRef { span: *span },
+            },
             upvar_def_span: None,
             upvar_span: None,
             fr_span: None,
@@ -682,6 +682,8 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
         let (_, mir_def_name) =
             self.infcx.tcx.article_and_description(self.mir_def_id().to_def_id());
 
+        let mut err = LifeTimeOutLiveErr { span: *span, category: None };
+
         let fr_name = self.give_region_a_name(*fr).unwrap();
         let outlived_fr_name = self.give_region_a_name(*outlived_fr).unwrap();
 
@@ -700,7 +702,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
             },
         };
 
-        let err = LifeTimeOutLiveErr { span: *span, category: err_category };
+        err.category = Some(err_category);
 
         let mut diag = self.infcx.tcx.sess.create_err(err);
 
@@ -854,7 +856,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                     ident.span,
                     "calling this method introduces the `impl`'s 'static` requirement",
                 );
-                err.span_note(multi_span, "the used `impl` has a `'static` requirement");
+                err.subdiagnostic(RequireStaticErr::UsedImpl { multi_span });
                 err.span_suggestion_verbose(
                     span.shrink_to_hi(),
                     "consider relaxing the implicit `'static` requirement",
diff --git a/compiler/rustc_borrowck/src/lib.rs b/compiler/rustc_borrowck/src/lib.rs
index 78c817150a65a..6333b771cece3 100644
--- a/compiler/rustc_borrowck/src/lib.rs
+++ b/compiler/rustc_borrowck/src/lib.rs
@@ -426,7 +426,8 @@ fn do_mir_borrowck<'a, 'tcx>(
             continue;
         }
 
-        tcx.emit_spanned_lint(UNUSED_MUT, lint_root, span, VarNeedNotMut { span })
+        let mut_span = tcx.sess.source_map().span_until_non_whitespace(span);
+        tcx.emit_spanned_lint(UNUSED_MUT, lint_root, span, VarNeedNotMut { span: mut_span })
     }
 
     let tainted_by_errors = mbcx.emit_errors();
diff --git a/compiler/rustc_borrowck/src/session_diagnostics.rs b/compiler/rustc_borrowck/src/session_diagnostics.rs
index ff2196760039c..3490c2dae5729 100644
--- a/compiler/rustc_borrowck/src/session_diagnostics.rs
+++ b/compiler/rustc_borrowck/src/session_diagnostics.rs
@@ -1,3 +1,4 @@
+use rustc_errors::MultiSpan;
 use rustc_macros::{LintDiagnostic, SessionDiagnostic, SessionSubdiagnostic};
 use rustc_middle::ty::Ty;
 use rustc_span::Span;
@@ -100,7 +101,7 @@ pub(crate) struct LifeTimeOutLiveErr {
     #[primary_span]
     pub span: Span,
     #[subdiagnostic]
-    pub category: LifeTimeReturnCategoryErr,
+    pub category: Option<LifeTimeReturnCategoryErr>,
 }
 
 #[derive(SessionSubdiagnostic)]
@@ -122,3 +123,12 @@ pub(crate) enum LifeTimeReturnCategoryErr {
         outlived_fr_name: String,
     },
 }
+
+#[derive(SessionSubdiagnostic)]
+pub(crate) enum RequireStaticErr {
+    #[note(borrowck::used_impl_require_static)]
+    UsedImpl {
+        #[primary_span]
+        multi_span: MultiSpan,
+    },
+}
diff --git a/compiler/rustc_error_messages/locales/en-US/borrowck.ftl b/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
index 6032e65a57d27..dbeaa564094f7 100644
--- a/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
+++ b/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
@@ -25,21 +25,25 @@ borrowck_var_does_not_need_mut =
     .suggestion = remove this `mut`
 
 borrowck_const_not_used_in_type_alias =
-    const parameter `{$ct}` is part of concrete type but not used in parameter list for the `impl Trait` type alias
+    const parameter `{$ct}` is part of concrete type but not
+     used in parameter list for the `impl Trait` type alias
 
 borrowck_var_cannot_escape_closure =
     captured variable cannot escape `FnMut` closure body
     .upvar_def = variable defined here
     .upvar = variable captured here
-    .fr =  "inferred to be a `FnMut` closure"
-    .note = `FnMut` closures only have access to their captured variables while they are executing...
+    .fr =  inferred to be a `FnMut` closure
+    .note = `FnMut` closures only have access to their captured variables while they are
+     executing...
     .cannot_escape = ...therefore, they cannot allow references to captured variables to escape
 
 borrowck_returned_closure_escaped =
-    returns a closure that contains a reference to a captured variable, which then escapes the closure body
+    returns a closure that contains a reference to a captured variable, which then
+     escapes the closure body
 
 borrowck_returned_async_block_escaped =
-    returns an `async` block that contains a reference to a captured variable, which then escapes the closure body
+    returns an `async` block that contains a reference to a captured variable, which then
+     escapes the closure body
 
 borrowck_returned_ref_escaped =
     returns a reference to a captured variable which escapes the closure body
@@ -48,7 +52,11 @@ borrowck_lifetime_constraints_error =
     lifetime may not live long enough
 
 borrowck_returned_lifetime_wrong =
-    {$mir_def_name} was supposed to return data with lifetime `{$outlived_fr_name}` but it is returning data with lifetime `{$fr_name}`
+    {$mir_def_name} was supposed to return data with lifetime `{$outlived_fr_name}` but it is returning
+     data with lifetime `{$fr_name}`
 
 borrowck_returned_lifetime_short =
     {$category_desc}requires that `{$free_region_name}` must outlive `{$outlived_fr_name}`
+
+borrowck_used_impl_require_static =
+    the used `impl` has a `'static` requirement

From b7aa1cc2f00bf0fe1d16e42aebd131528a518aba Mon Sep 17 00:00:00 2001
From: AndyJado <101876416+AndyJado@users.noreply.github.com>
Date: Mon, 22 Aug 2022 20:28:31 +0800
Subject: [PATCH 09/10] ui fix

---
 .../src/diagnostics/region_errors.rs          | 26 +++++++++----------
 compiler/rustc_borrowck/src/lib.rs            |  3 +--
 .../rustc_borrowck/src/session_diagnostics.rs | 12 +--------
 .../locales/en-US/borrowck.ftl                |  1 -
 4 files changed, 14 insertions(+), 28 deletions(-)

diff --git a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
index 66b036d194af9..6894ec7956cfe 100644
--- a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
@@ -27,7 +27,7 @@ use rustc_span::Span;
 use crate::borrowck_errors;
 use crate::session_diagnostics::{
     FnMutError, FnMutReturnTypeErr, GenericDoesNotLiveLongEnough, LifeTimeOutLiveErr,
-    LifeTimeReturnCategoryErr, RequireStaticErr,
+    LifeTimeReturnCategoryErr,
 };
 
 use super::{OutlivesSuggestionBuilder, RegionName};
@@ -500,17 +500,17 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
 
         debug!("report_fnmut_error: output_ty={:?}", output_ty);
 
+        let ty_err = match output_ty.kind() {
+            ty::Closure(_, _) => FnMutReturnTypeErr::ReturnClosure { span: *span },
+            ty::Adt(def, _) if self.infcx.tcx.is_diagnostic_item(sym::gen_future, def.did()) => {
+                FnMutReturnTypeErr::ReturnAsyncBlock { span: *span }
+            }
+            _ => FnMutReturnTypeErr::ReturnRef { span: *span },
+        };
+
         let mut err = FnMutError {
             span: *span,
-            ty_err: match output_ty.kind() {
-                ty::Closure(_, _) => FnMutReturnTypeErr::ReturnClosure { span: *span },
-                ty::Adt(def, _)
-                    if self.infcx.tcx.is_diagnostic_item(sym::gen_future, def.did()) =>
-                {
-                    FnMutReturnTypeErr::ReturnAsyncBlock { span: *span }
-                }
-                _ => FnMutReturnTypeErr::ReturnRef { span: *span },
-            },
+            ty_err,
             upvar_def_span: None,
             upvar_span: None,
             fr_span: None,
@@ -682,8 +682,6 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
         let (_, mir_def_name) =
             self.infcx.tcx.article_and_description(self.mir_def_id().to_def_id());
 
-        let mut err = LifeTimeOutLiveErr { span: *span, category: None };
-
         let fr_name = self.give_region_a_name(*fr).unwrap();
         let outlived_fr_name = self.give_region_a_name(*outlived_fr).unwrap();
 
@@ -702,7 +700,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
             },
         };
 
-        err.category = Some(err_category);
+        let err = LifeTimeOutLiveErr { span: *span, category: err_category };
 
         let mut diag = self.infcx.tcx.sess.create_err(err);
 
@@ -856,7 +854,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                     ident.span,
                     "calling this method introduces the `impl`'s 'static` requirement",
                 );
-                err.subdiagnostic(RequireStaticErr::UsedImpl { multi_span });
+                err.span_note(multi_span, "the used `impl` has a `'static` requirement");
                 err.span_suggestion_verbose(
                     span.shrink_to_hi(),
                     "consider relaxing the implicit `'static` requirement",
diff --git a/compiler/rustc_borrowck/src/lib.rs b/compiler/rustc_borrowck/src/lib.rs
index 6333b771cece3..78c817150a65a 100644
--- a/compiler/rustc_borrowck/src/lib.rs
+++ b/compiler/rustc_borrowck/src/lib.rs
@@ -426,8 +426,7 @@ fn do_mir_borrowck<'a, 'tcx>(
             continue;
         }
 
-        let mut_span = tcx.sess.source_map().span_until_non_whitespace(span);
-        tcx.emit_spanned_lint(UNUSED_MUT, lint_root, span, VarNeedNotMut { span: mut_span })
+        tcx.emit_spanned_lint(UNUSED_MUT, lint_root, span, VarNeedNotMut { span })
     }
 
     let tainted_by_errors = mbcx.emit_errors();
diff --git a/compiler/rustc_borrowck/src/session_diagnostics.rs b/compiler/rustc_borrowck/src/session_diagnostics.rs
index 3490c2dae5729..ff2196760039c 100644
--- a/compiler/rustc_borrowck/src/session_diagnostics.rs
+++ b/compiler/rustc_borrowck/src/session_diagnostics.rs
@@ -1,4 +1,3 @@
-use rustc_errors::MultiSpan;
 use rustc_macros::{LintDiagnostic, SessionDiagnostic, SessionSubdiagnostic};
 use rustc_middle::ty::Ty;
 use rustc_span::Span;
@@ -101,7 +100,7 @@ pub(crate) struct LifeTimeOutLiveErr {
     #[primary_span]
     pub span: Span,
     #[subdiagnostic]
-    pub category: Option<LifeTimeReturnCategoryErr>,
+    pub category: LifeTimeReturnCategoryErr,
 }
 
 #[derive(SessionSubdiagnostic)]
@@ -123,12 +122,3 @@ pub(crate) enum LifeTimeReturnCategoryErr {
         outlived_fr_name: String,
     },
 }
-
-#[derive(SessionSubdiagnostic)]
-pub(crate) enum RequireStaticErr {
-    #[note(borrowck::used_impl_require_static)]
-    UsedImpl {
-        #[primary_span]
-        multi_span: MultiSpan,
-    },
-}
diff --git a/compiler/rustc_error_messages/locales/en-US/borrowck.ftl b/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
index bea573b403bae..dbeaa564094f7 100644
--- a/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
+++ b/compiler/rustc_error_messages/locales/en-US/borrowck.ftl
@@ -35,7 +35,6 @@ borrowck_var_cannot_escape_closure =
     .fr =  inferred to be a `FnMut` closure
     .note = `FnMut` closures only have access to their captured variables while they are
      executing...
-    .note = `FnMut` closures only have access to their captured variables while they are executing...
     .cannot_escape = ...therefore, they cannot allow references to captured variables to escape
 
 borrowck_returned_closure_escaped =

From 55d47effcfa6efd737ef0cb1cebfb803f6695597 Mon Sep 17 00:00:00 2001
From: AndyJado <101876416+AndyJado@users.noreply.github.com>
Date: Mon, 22 Aug 2022 20:37:40 +0800
Subject: [PATCH 10/10] sub diagnostic

---
 .../src/diagnostics/region_errors.rs          | 26 ++++++++++---------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
index 6894ec7956cfe..66b036d194af9 100644
--- a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
@@ -27,7 +27,7 @@ use rustc_span::Span;
 use crate::borrowck_errors;
 use crate::session_diagnostics::{
     FnMutError, FnMutReturnTypeErr, GenericDoesNotLiveLongEnough, LifeTimeOutLiveErr,
-    LifeTimeReturnCategoryErr,
+    LifeTimeReturnCategoryErr, RequireStaticErr,
 };
 
 use super::{OutlivesSuggestionBuilder, RegionName};
@@ -500,17 +500,17 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
 
         debug!("report_fnmut_error: output_ty={:?}", output_ty);
 
-        let ty_err = match output_ty.kind() {
-            ty::Closure(_, _) => FnMutReturnTypeErr::ReturnClosure { span: *span },
-            ty::Adt(def, _) if self.infcx.tcx.is_diagnostic_item(sym::gen_future, def.did()) => {
-                FnMutReturnTypeErr::ReturnAsyncBlock { span: *span }
-            }
-            _ => FnMutReturnTypeErr::ReturnRef { span: *span },
-        };
-
         let mut err = FnMutError {
             span: *span,
-            ty_err,
+            ty_err: match output_ty.kind() {
+                ty::Closure(_, _) => FnMutReturnTypeErr::ReturnClosure { span: *span },
+                ty::Adt(def, _)
+                    if self.infcx.tcx.is_diagnostic_item(sym::gen_future, def.did()) =>
+                {
+                    FnMutReturnTypeErr::ReturnAsyncBlock { span: *span }
+                }
+                _ => FnMutReturnTypeErr::ReturnRef { span: *span },
+            },
             upvar_def_span: None,
             upvar_span: None,
             fr_span: None,
@@ -682,6 +682,8 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
         let (_, mir_def_name) =
             self.infcx.tcx.article_and_description(self.mir_def_id().to_def_id());
 
+        let mut err = LifeTimeOutLiveErr { span: *span, category: None };
+
         let fr_name = self.give_region_a_name(*fr).unwrap();
         let outlived_fr_name = self.give_region_a_name(*outlived_fr).unwrap();
 
@@ -700,7 +702,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
             },
         };
 
-        let err = LifeTimeOutLiveErr { span: *span, category: err_category };
+        err.category = Some(err_category);
 
         let mut diag = self.infcx.tcx.sess.create_err(err);
 
@@ -854,7 +856,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                     ident.span,
                     "calling this method introduces the `impl`'s 'static` requirement",
                 );
-                err.span_note(multi_span, "the used `impl` has a `'static` requirement");
+                err.subdiagnostic(RequireStaticErr::UsedImpl { multi_span });
                 err.span_suggestion_verbose(
                     span.shrink_to_hi(),
                     "consider relaxing the implicit `'static` requirement",