Auto merge of rust-lang#137295 - matthiaskrgr:rollup-tdu3t39, r=matthiaskrgr

Rollup of 9 pull requests

Successful merges:

 - rust-lang#135296 (interpret: adjust vtable validity check for higher-ranked types)
 - rust-lang#137106 (Add customized compare for Link in rustdoc)
 - rust-lang#137253 (Restrict `bevy_ecs` `ParamSet` hack)
 - rust-lang#137262 (Make fewer crates depend on `rustc_ast_ir`)
 - rust-lang#137263 (Register `USAGE_OF_TYPE_IR_INHERENT`, remove inherent usages)
 - rust-lang#137266 (MIR visitor tweaks)
 - rust-lang#137269 (Pattern Migration 2024: properly label `&` patterns whose subpatterns are from macro expansions)
 - rust-lang#137277 (stabilize `inherent_str_constructors`)
 - rust-lang#137281 (Tweak "expected ident" parse error to avoid talking about doc comments)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

Diff for: Cargo.lock

@@ -3748,7 +3748,6 @@ dependencies = [
  "itertools",
  "rustc_abi",
  "rustc_ast",
- "rustc_ast_ir",
  "rustc_attr_parsing",
  "rustc_data_structures",
  "rustc_errors",
@@ -3813,7 +3812,6 @@ dependencies = [
 name = "rustc_infer"
 version = "0.0.0"
 dependencies = [
- "rustc_ast_ir",
  "rustc_data_structures",
  "rustc_errors",
  "rustc_fluent_macro",
@@ -4004,7 +4002,6 @@ dependencies = [
  "rustc_apfloat",
  "rustc_arena",
  "rustc_ast",
- "rustc_ast_ir",
  "rustc_attr_parsing",
  "rustc_data_structures",
  "rustc_error_messages",
@@ -4134,7 +4131,6 @@ name = "rustc_next_trait_solver"
 version = "0.0.0"
 dependencies = [
  "derive-where",
- "rustc_ast_ir",
  "rustc_data_structures",
  "rustc_index",
  "rustc_macros",
@@ -4454,7 +4450,6 @@ dependencies = [
  "itertools",
  "rustc_abi",
  "rustc_ast",
- "rustc_ast_ir",
  "rustc_attr_parsing",
  "rustc_data_structures",
  "rustc_errors",
@@ -4493,7 +4488,6 @@ version = "0.0.0"
 dependencies = [
  "itertools",
  "rustc_abi",
- "rustc_ast_ir",
  "rustc_data_structures",
  "rustc_hir",
  "rustc_infer",
@@ -4509,7 +4503,6 @@ version = "0.0.0"
 dependencies = [
  "itertools",
  "rustc_abi",
- "rustc_ast_ir",
  "rustc_data_structures",
  "rustc_errors",
  "rustc_fluent_macro",

Diff for: compiler/rustc_ast_ir/src/lib.rs

@@ -1,3 +1,10 @@
+//! Common utilities shared by both `rustc_ast` and `rustc_type_ir`.
+//!
+//! Don't depend on this crate directly; both of those crates should re-export
+//! the functionality. Additionally, if you're in scope of `rustc_middle`, then
+//! prefer imports via that too, to avoid needing to directly depend on (e.g.)
+//! `rustc_type_ir` for a single import.
+
 // tidy-alphabetical-start
 #![cfg_attr(feature = "nightly", allow(internal_features))]
 #![cfg_attr(feature = "nightly", feature(never_type))]

Diff for: compiler/rustc_borrowck/src/diagnostics/find_use.rs

@@ -1,7 +1,7 @@
 use std::collections::VecDeque;
 
 use rustc_data_structures::fx::FxIndexSet;
-use rustc_middle::mir::visit::{MirVisitable, PlaceContext, Visitor};
+use rustc_middle::mir::visit::{PlaceContext, Visitor};
 use rustc_middle::mir::{self, Body, Local, Location};
 use rustc_middle::ty::{RegionVid, TyCtxt};
 
@@ -45,7 +45,22 @@ impl<'a, 'tcx> UseFinder<'a, 'tcx> {
 
             let block_data = &self.body[p.block];
 
-            match self.def_use(p, block_data.visitable(p.statement_index)) {
+            let mut visitor = DefUseVisitor {
+                body: self.body,
+                tcx: self.tcx,
+                region_vid: self.region_vid,
+                def_use_result: None,
+            };
+
+            let is_statement = p.statement_index < block_data.statements.len();
+
+            if is_statement {
+                visitor.visit_statement(&block_data.statements[p.statement_index], p);
+            } else {
+                visitor.visit_terminator(block_data.terminator.as_ref().unwrap(), p);
+            }
+
+            match visitor.def_use_result {
                 Some(DefUseResult::Def) => {}
 
                 Some(DefUseResult::UseLive { local }) => {
@@ -57,7 +72,7 @@ impl<'a, 'tcx> UseFinder<'a, 'tcx> {
                 }
 
                 None => {
-                    if p.statement_index < block_data.statements.len() {
+                    if is_statement {
                         queue.push_back(p.successor_within_block());
                     } else {
                         queue.extend(
@@ -77,19 +92,6 @@ impl<'a, 'tcx> UseFinder<'a, 'tcx> {
 
         None
     }
-
-    fn def_use(&self, location: Location, thing: &dyn MirVisitable<'tcx>) -> Option<DefUseResult> {
-        let mut visitor = DefUseVisitor {
-            body: self.body,
-            tcx: self.tcx,
-            region_vid: self.region_vid,
-            def_use_result: None,
-        };
-
-        thing.apply(location, &mut visitor);
-
-        visitor.def_use_result
-    }
 }
 
 struct DefUseVisitor<'a, 'tcx> {

Diff for: compiler/rustc_const_eval/src/interpret/cast.rs

@@ -430,10 +430,12 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                     };
                     let erased_trait_ref =
                         ty::ExistentialTraitRef::erase_self_ty(*self.tcx, upcast_trait_ref);
-                    assert!(data_b.principal().is_some_and(|b| self.eq_in_param_env(
-                        erased_trait_ref,
-                        self.tcx.instantiate_bound_regions_with_erased(b)
-                    )));
+                    assert_eq!(
+                        data_b.principal().map(|b| {
+                            self.tcx.normalize_erasing_late_bound_regions(self.typing_env, b)
+                        }),
+                        Some(erased_trait_ref),
+                    );
                 } else {
                     // In this case codegen would keep using the old vtable. We don't want to do
                     // that as it has the wrong trait. The reason codegen can do this is that

Diff for: compiler/rustc_const_eval/src/interpret/eval_context.rs

@@ -4,9 +4,6 @@ use either::{Left, Right};
 use rustc_abi::{Align, HasDataLayout, Size, TargetDataLayout};
 use rustc_errors::DiagCtxtHandle;
 use rustc_hir::def_id::DefId;
-use rustc_infer::infer::TyCtxtInferExt;
-use rustc_infer::infer::at::ToTrace;
-use rustc_infer::traits::ObligationCause;
 use rustc_middle::mir::interpret::{ErrorHandled, InvalidMetaKind, ReportedErrorInfo};
 use rustc_middle::query::TyCtxtAt;
 use rustc_middle::ty::layout::{
@@ -17,8 +14,7 @@ use rustc_middle::{mir, span_bug};
 use rustc_session::Limit;
 use rustc_span::Span;
 use rustc_target::callconv::FnAbi;
-use rustc_trait_selection::traits::ObligationCtxt;
-use tracing::{debug, instrument, trace};
+use tracing::{debug, trace};
 
 use super::{
     Frame, FrameInfo, GlobalId, InterpErrorInfo, InterpErrorKind, InterpResult, MPlaceTy, Machine,
@@ -320,40 +316,6 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         }
     }
 
-    /// Check if the two things are equal in the current param_env, using an infcx to get proper
-    /// equality checks.
-    #[instrument(level = "trace", skip(self), ret)]
-    pub(super) fn eq_in_param_env<T>(&self, a: T, b: T) -> bool
-    where
-        T: PartialEq + TypeFoldable<TyCtxt<'tcx>> + ToTrace<'tcx>,
-    {
-        // Fast path: compare directly.
-        if a == b {
-            return true;
-        }
-        // Slow path: spin up an inference context to check if these traits are sufficiently equal.
-        let (infcx, param_env) = self.tcx.infer_ctxt().build_with_typing_env(self.typing_env);
-        let ocx = ObligationCtxt::new(&infcx);
-        let cause = ObligationCause::dummy_with_span(self.cur_span());
-        // equate the two trait refs after normalization
-        let a = ocx.normalize(&cause, param_env, a);
-        let b = ocx.normalize(&cause, param_env, b);
-
-        if let Err(terr) = ocx.eq(&cause, param_env, a, b) {
-            trace!(?terr);
-            return false;
-        }
-
-        let errors = ocx.select_all_or_error();
-        if !errors.is_empty() {
-            trace!(?errors);
-            return false;
-        }
-
-        // All good.
-        true
-    }
-
     /// Walks up the callstack from the intrinsic's callsite, searching for the first callsite in a
     /// frame which is not `#[track_caller]`. This matches the `caller_location` intrinsic,
     /// and is primarily intended for the panic machinery.

Diff for: compiler/rustc_const_eval/src/interpret/traits.rs

@@ -86,21 +86,15 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
             throw_ub!(InvalidVTableTrait { vtable_dyn_type, expected_dyn_type });
         }
 
+        // This checks whether there is a subtyping relation between the predicates in either direction.
+        // For example:
+        // - casting between `dyn for<'a> Trait<fn(&'a u8)>` and `dyn Trait<fn(&'static u8)>` is OK
+        // - casting between `dyn Trait<for<'a> fn(&'a u8)>` and either of the above is UB
         for (a_pred, b_pred) in std::iter::zip(sorted_vtable, sorted_expected) {
-            let is_eq = match (a_pred.skip_binder(), b_pred.skip_binder()) {
-                (
-                    ty::ExistentialPredicate::Trait(a_data),
-                    ty::ExistentialPredicate::Trait(b_data),
-                ) => self.eq_in_param_env(a_pred.rebind(a_data), b_pred.rebind(b_data)),
+            let a_pred = self.tcx.normalize_erasing_late_bound_regions(self.typing_env, a_pred);
+            let b_pred = self.tcx.normalize_erasing_late_bound_regions(self.typing_env, b_pred);
 
-                (
-                    ty::ExistentialPredicate::Projection(a_data),
-                    ty::ExistentialPredicate::Projection(b_data),
-                ) => self.eq_in_param_env(a_pred.rebind(a_data), b_pred.rebind(b_data)),
-
-                _ => false,
-            };
-            if !is_eq {
+            if a_pred != b_pred {
                 throw_ub!(InvalidVTableTrait { vtable_dyn_type, expected_dyn_type });
             }
         }

Diff for: compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -16,7 +16,6 @@ use rustc_lint_defs::builtin::SUPERTRAIT_ITEM_SHADOWING_DEFINITION;
 use rustc_macros::LintDiagnostic;
 use rustc_middle::mir::interpret::ErrorHandled;
 use rustc_middle::query::Providers;
-use rustc_middle::ty::print::with_no_trimmed_paths;
 use rustc_middle::ty::trait_def::TraitSpecializationKind;
 use rustc_middle::ty::{
     self, AdtKind, GenericArgKind, GenericArgs, GenericParamDefKind, Ty, TyCtxt, TypeFoldable,
@@ -143,33 +142,7 @@ where
         return Ok(());
     }
 
-    let is_bevy = 'is_bevy: {
-        // We don't want to emit this for dependents of Bevy, for now.
-        // See #119956
-        let is_bevy_paramset = |def: ty::AdtDef<'_>| {
-            let adt_did = with_no_trimmed_paths!(infcx.tcx.def_path_str(def.0.did));
-            adt_did.contains("ParamSet")
-        };
-        for ty in assumed_wf_types.iter() {
-            match ty.kind() {
-                ty::Adt(def, _) => {
-                    if is_bevy_paramset(*def) {
-                        break 'is_bevy true;
-                    }
-                }
-                ty::Ref(_, ty, _) => match ty.kind() {
-                    ty::Adt(def, _) => {
-                        if is_bevy_paramset(*def) {
-                            break 'is_bevy true;
-                        }
-                    }
-                    _ => {}
-                },
-                _ => {}
-            }
-        }
-        false
-    };
+    let is_bevy = assumed_wf_types.visit_with(&mut ContainsBevyParamSet { tcx }).is_break();
 
     // If we have set `no_implied_bounds_compat`, then do not attempt compatibility.
     // We could also just always enter if `is_bevy`, and call `implied_bounds_tys`,
@@ -194,6 +167,31 @@ where
     }
 }
 
+struct ContainsBevyParamSet<'tcx> {
+    tcx: TyCtxt<'tcx>,
+}
+
+impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for ContainsBevyParamSet<'tcx> {
+    type Result = ControlFlow<()>;
+
+    fn visit_ty(&mut self, t: Ty<'tcx>) -> Self::Result {
+        // We only care to match `ParamSet<T>` or `&ParamSet<T>`.
+        match t.kind() {
+            ty::Adt(def, _) => {
+                if self.tcx.item_name(def.did()) == sym::ParamSet
+                    && self.tcx.crate_name(def.did().krate) == sym::bevy_ecs
+                {
+                    return ControlFlow::Break(());
+                }
+            }
+            ty::Ref(_, ty, _) => ty.visit_with(self)?,
+            _ => {}
+        }
+
+        ControlFlow::Continue(())
+    }
+}
+
 fn check_well_formed(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Result<(), ErrorGuaranteed> {
     let node = tcx.hir_node_by_def_id(def_id);
     let mut res = match node {

Diff for: compiler/rustc_hir_typeck/Cargo.toml

@@ -8,7 +8,6 @@ edition = "2021"
 itertools = "0.12"
 rustc_abi = { path = "../rustc_abi" }
 rustc_ast = { path = "../rustc_ast" }
-rustc_ast_ir = { path = "../rustc_ast_ir" }
 rustc_attr_parsing = { path = "../rustc_attr_parsing" }
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_errors = { path = "../rustc_errors" }

Diff for: compiler/rustc_hir_typeck/src/pat.rs

@@ -847,20 +847,23 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     self.add_rust_2024_migration_desugared_pat(
                         pat_info.top_info.hir_id,
                         pat,
-                        ident.span,
+                        't', // last char of `mut`
                         def_br_mutbl,
                     );
                     BindingMode(ByRef::No, Mutability::Mut)
                 }
             }
             BindingMode(ByRef::No, mutbl) => BindingMode(def_br, mutbl),
-            BindingMode(ByRef::Yes(_), _) => {
+            BindingMode(ByRef::Yes(user_br_mutbl), _) => {
                 if let ByRef::Yes(def_br_mutbl) = def_br {
                     // `ref`/`ref mut` overrides the binding mode on edition <= 2021
                     self.add_rust_2024_migration_desugared_pat(
                         pat_info.top_info.hir_id,
                         pat,
-                        ident.span,
+                        match user_br_mutbl {
+                            Mutability::Not => 'f', // last char of `ref`
+                            Mutability::Mut => 't', // last char of `ref mut`
+                        },
                         def_br_mutbl,
                     );
                 }
@@ -2440,7 +2443,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     self.add_rust_2024_migration_desugared_pat(
                         pat_info.top_info.hir_id,
                         pat,
-                        inner.span,
+                        match pat_mutbl {
+                            Mutability::Not => '&', // last char of `&`
+                            Mutability::Mut => 't', // last char of `&mut`
+                        },
                         inh_mut,
                     )
                 }
@@ -2832,18 +2838,20 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         &self,
         pat_id: HirId,
         subpat: &'tcx Pat<'tcx>,
-        cutoff_span: Span,
+        final_char: char,
         def_br_mutbl: Mutability,
     ) {
         // Try to trim the span we're labeling to just the `&` or binding mode that's an issue.
-        // If the subpattern's span is is from an expansion, the emitted label will not be trimmed.
-        let source_map = self.tcx.sess.source_map();
-        let cutoff_span = source_map
-            .span_extend_prev_while(cutoff_span, |c| c.is_whitespace() || c == '(')
-            .unwrap_or(cutoff_span);
-        // Ensure we use the syntax context and thus edition of `subpat.span`; this will be a hard
-        // error if the subpattern is of edition >= 2024.
-        let trimmed_span = subpat.span.until(cutoff_span).with_ctxt(subpat.span.ctxt());
+        let from_expansion = subpat.span.from_expansion();
+        let trimmed_span = if from_expansion {
+            // If the subpattern is from an expansion, highlight the whole macro call instead.
+            subpat.span
+        } else {
+            let trimmed = self.tcx.sess.source_map().span_through_char(subpat.span, final_char);
+            // The edition of the trimmed span should be the same as `subpat.span`; this will be a
+            // a hard error if the subpattern is of edition >= 2024. We set it manually to be sure:
+            trimmed.with_ctxt(subpat.span.ctxt())
+        };
 
         let mut typeck_results = self.typeck_results.borrow_mut();
         let mut table = typeck_results.rust_2024_migration_desugared_pats_mut();
@@ -2877,7 +2885,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         };
         // Only provide a detailed label if the problematic subpattern isn't from an expansion.
         // In the case that it's from a macro, we'll add a more detailed note in the emitter.
-        let from_expansion = subpat.span.from_expansion();
         let primary_label = if from_expansion {
             // We can't suggest eliding modifiers within expansions.
             info.suggest_eliding_modes = false;