Auto merge of #81113 - m-ou-se:rollup-a1unz4x, r=m-ou-se

Rollup of 13 pull requests

Successful merges:

 - #79298 (correctly deal with late-bound lifetimes in anon consts)
 - #80031 (resolve: Reject ambiguity built-in attr vs different built-in attr)
 - #80201 (Add benchmark and fast path for BufReader::read_exact)
 - #80635 (Improve diagnostics when closure doesn't meet trait bound)
 - #80765 (resolve: Simplify collection of traits in scope)
 - #80932 (Allow downloading LLVM on Windows and MacOS)
 - #80983 (Remove is_dllimport_foreign_item definition from cg_ssa)
 - #81064 (Support non-stage0 check)
 - #81080 (Force vec![] to expression position only)
 - #81082 (BTreeMap: clean up a few more comments)
 - #81084 (Use Option::map instead of open-coding it)
 - #81095 (Use Option::unwrap_or instead of open-coding it)
 - #81107 (Add NonZeroUn::is_power_of_two)

Failed merges:

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

Author: bors

Diff for: compiler/rustc_codegen_llvm/src/llvm_util.rs

@@ -214,11 +214,7 @@ fn handle_native(name: &str) -> &str {
 }
 
 pub fn target_cpu(sess: &Session) -> &str {
-    let name = match sess.opts.cg.target_cpu {
-        Some(ref s) => &**s,
-        None => &*sess.target.cpu,
-    };
-
+    let name = sess.opts.cg.target_cpu.as_ref().unwrap_or(&sess.target.cpu);
     handle_native(name)
 }
 
@@ -254,8 +250,6 @@ pub fn handle_native_features(sess: &Session) -> Vec<String> {
 }
 
 pub fn tune_cpu(sess: &Session) -> Option<&str> {
-    match sess.opts.debugging_opts.tune_cpu {
-        Some(ref s) => Some(handle_native(&**s)),
-        None => None,
-    }
+    let name = sess.opts.debugging_opts.tune_cpu.as_ref()?;
+    Some(handle_native(name))
 }

Diff for: compiler/rustc_codegen_ssa/src/base.rs

@@ -29,7 +29,6 @@ use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::{self, Instance, Ty, TyCtxt};
 use rustc_session::cgu_reuse_tracker::CguReuse;
 use rustc_session::config::{self, EntryFnType};
-use rustc_session::utils::NativeLibKind;
 use rustc_session::Session;
 use rustc_target::abi::{Align, LayoutOf, VariantIdx};
 
@@ -817,32 +816,6 @@ pub fn provide_both(providers: &mut Providers) {
         }
         tcx.sess.opts.optimize
     };
-
-    providers.dllimport_foreign_items = |tcx, krate| {
-        let module_map = tcx.foreign_modules(krate);
-
-        let dllimports = tcx
-            .native_libraries(krate)
-            .iter()
-            .filter(|lib| {
-                if !matches!(lib.kind, NativeLibKind::Dylib | NativeLibKind::Unspecified) {
-                    return false;
-                }
-                let cfg = match lib.cfg {
-                    Some(ref cfg) => cfg,
-                    None => return true,
-                };
-                attr::cfg_matches(cfg, &tcx.sess.parse_sess, None)
-            })
-            .filter_map(|lib| lib.foreign_module)
-            .map(|id| &module_map[&id])
-            .flat_map(|module| module.foreign_items.iter().cloned())
-            .collect();
-        dllimports
-    };
-
-    providers.is_dllimport_foreign_item =
-        |tcx, def_id| tcx.dllimport_foreign_items(def_id.krate).contains(&def_id);
 }
 
 fn determine_cgu_reuse<'tcx>(tcx: TyCtxt<'tcx>, cgu: &CodegenUnit<'tcx>) -> CguReuse {

Diff for: compiler/rustc_expand/src/mbe/macro_rules.rs

@@ -56,36 +56,11 @@ crate fn annotate_err_with_kind(
     };
 }
 
-/// Instead of e.g. `vec![a, b, c]` in a pattern context, suggest `[a, b, c]`.
-fn suggest_slice_pat(e: &mut DiagnosticBuilder<'_>, site_span: Span, parser: &Parser<'_>) {
-    let mut suggestion = None;
-    if let Ok(code) = parser.sess.source_map().span_to_snippet(site_span) {
-        if let Some(bang) = code.find('!') {
-            suggestion = Some(code[bang + 1..].to_string());
-        }
-    }
-    if let Some(suggestion) = suggestion {
-        e.span_suggestion(
-            site_span,
-            "use a slice pattern here instead",
-            suggestion,
-            Applicability::MachineApplicable,
-        );
-    } else {
-        e.span_label(site_span, "use a slice pattern here instead");
-    }
-    e.help(
-        "for more information, see https://doc.rust-lang.org/edition-guide/\
-        rust-2018/slice-patterns.html",
-    );
-}
-
 fn emit_frag_parse_err(
     mut e: DiagnosticBuilder<'_>,
     parser: &Parser<'_>,
     orig_parser: &mut Parser<'_>,
     site_span: Span,
-    macro_ident: Ident,
     arm_span: Span,
     kind: AstFragmentKind,
 ) {
@@ -113,9 +88,6 @@ fn emit_frag_parse_err(
         e.span_label(site_span, "in this macro invocation");
     }
     match kind {
-        AstFragmentKind::Pat if macro_ident.name == sym::vec => {
-            suggest_slice_pat(&mut e, site_span, parser);
-        }
         // Try a statement if an expression is wanted but failed and suggest adding `;` to call.
         AstFragmentKind::Expr => match parse_ast_fragment(orig_parser, AstFragmentKind::Stmts) {
             Err(mut err) => err.cancel(),
@@ -143,7 +115,7 @@ impl<'a> ParserAnyMacro<'a> {
         let fragment = match parse_ast_fragment(parser, kind) {
             Ok(f) => f,
             Err(err) => {
-                emit_frag_parse_err(err, parser, snapshot, site_span, macro_ident, arm_span, kind);
+                emit_frag_parse_err(err, parser, snapshot, site_span, arm_span, kind);
                 return kind.dummy(site_span);
             }
         };

Diff for: compiler/rustc_hir/src/def.rs

@@ -5,6 +5,7 @@ use rustc_ast as ast;
 use rustc_ast::NodeId;
 use rustc_macros::HashStable_Generic;
 use rustc_span::hygiene::MacroKind;
+use rustc_span::Symbol;
 
 use std::array::IntoIter;
 use std::fmt::Debug;
@@ -34,7 +35,7 @@ pub enum CtorKind {
 #[derive(HashStable_Generic)]
 pub enum NonMacroAttrKind {
     /// Single-segment attribute defined by the language (`#[inline]`)
-    Builtin,
+    Builtin(Symbol),
     /// Multi-segment custom attribute living in a "tool module" (`#[rustfmt::skip]`).
     Tool,
     /// Single-segment custom attribute registered by a derive macro (`#[serde(default)]`).
@@ -371,7 +372,7 @@ impl CtorKind {
 impl NonMacroAttrKind {
     pub fn descr(self) -> &'static str {
         match self {
-            NonMacroAttrKind::Builtin => "built-in attribute",
+            NonMacroAttrKind::Builtin(..) => "built-in attribute",
             NonMacroAttrKind::Tool => "tool attribute",
             NonMacroAttrKind::DeriveHelper | NonMacroAttrKind::DeriveHelperCompat => {
                 "derive helper attribute"
@@ -393,7 +394,7 @@ impl NonMacroAttrKind {
             NonMacroAttrKind::Tool
             | NonMacroAttrKind::DeriveHelper
             | NonMacroAttrKind::DeriveHelperCompat => true,
-            NonMacroAttrKind::Builtin | NonMacroAttrKind::Registered => false,
+            NonMacroAttrKind::Builtin(..) | NonMacroAttrKind::Registered => false,
         }
     }
 }

Diff for: compiler/rustc_middle/src/query/mod.rs

@@ -1281,11 +1281,6 @@ rustc_queries! {
     }
 
     Other {
-        query dllimport_foreign_items(_: CrateNum)
-            -> FxHashSet<DefId> {
-            storage(ArenaCacheSelector<'tcx>)
-            desc { "dllimport_foreign_items" }
-        }
         query is_dllimport_foreign_item(def_id: DefId) -> bool {
             desc { |tcx| "is_dllimport_foreign_item({})", tcx.def_path_str(def_id) }
         }
@@ -1316,7 +1311,7 @@ rustc_queries! {
             desc { "looking up a named region" }
         }
         query is_late_bound_map(_: LocalDefId) ->
-            Option<&'tcx FxHashSet<ItemLocalId>> {
+            Option<(LocalDefId, &'tcx FxHashSet<ItemLocalId>)> {
             desc { "testing if a region is late bound" }
         }
         query object_lifetime_defaults_map(_: LocalDefId)

Diff for: compiler/rustc_middle/src/ty/context.rs

@@ -3,6 +3,7 @@
 use crate::arena::Arena;
 use crate::dep_graph::DepGraph;
 use crate::hir::exports::ExportMap;
+use crate::hir::place::Place as HirPlace;
 use crate::ich::{NodeIdHashingMode, StableHashingContext};
 use crate::infer::canonical::{Canonical, CanonicalVarInfo, CanonicalVarInfos};
 use crate::lint::{struct_lint_level, LintDiagnosticBuilder, LintLevelSource};
@@ -379,7 +380,7 @@ pub struct TypeckResults<'tcx> {
 
     /// Records the reasons that we picked the kind of each closure;
     /// not all closures are present in the map.
-    closure_kind_origins: ItemLocalMap<(Span, Symbol)>,
+    closure_kind_origins: ItemLocalMap<(Span, HirPlace<'tcx>)>,
 
     /// For each fn, records the "liberated" types of its arguments
     /// and return type. Liberated means that all bound regions
@@ -642,11 +643,13 @@ impl<'tcx> TypeckResults<'tcx> {
         self.upvar_capture_map[&upvar_id]
     }
 
-    pub fn closure_kind_origins(&self) -> LocalTableInContext<'_, (Span, Symbol)> {
+    pub fn closure_kind_origins(&self) -> LocalTableInContext<'_, (Span, HirPlace<'tcx>)> {
         LocalTableInContext { hir_owner: self.hir_owner, data: &self.closure_kind_origins }
     }
 
-    pub fn closure_kind_origins_mut(&mut self) -> LocalTableInContextMut<'_, (Span, Symbol)> {
+    pub fn closure_kind_origins_mut(
+        &mut self,
+    ) -> LocalTableInContextMut<'_, (Span, HirPlace<'tcx>)> {
         LocalTableInContextMut { hir_owner: self.hir_owner, data: &mut self.closure_kind_origins }
     }
 
@@ -2578,7 +2581,8 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 
     pub fn is_late_bound(self, id: HirId) -> bool {
-        self.is_late_bound_map(id.owner).map_or(false, |set| set.contains(&id.local_id))
+        self.is_late_bound_map(id.owner)
+            .map_or(false, |(owner, set)| owner == id.owner && set.contains(&id.local_id))
     }
 
     pub fn object_lifetime_defaults(self, id: HirId) -> Option<&'tcx [ObjectLifetimeDefault]> {

Diff for: compiler/rustc_middle/src/ty/mod.rs

@@ -17,7 +17,9 @@ pub use self::IntVarValue::*;
 pub use self::Variance::*;
 
 use crate::hir::exports::ExportMap;
-use crate::hir::place::Place as HirPlace;
+use crate::hir::place::{
+    Place as HirPlace, PlaceBase as HirPlaceBase, ProjectionKind as HirProjectionKind,
+};
 use crate::ich::StableHashingContext;
 use crate::middle::cstore::CrateStoreDyn;
 use crate::middle::resolve_lifetime::ObjectLifetimeDefault;
@@ -734,6 +736,43 @@ pub struct CapturedPlace<'tcx> {
     pub info: CaptureInfo<'tcx>,
 }
 
+pub fn place_to_string_for_capture(tcx: TyCtxt<'tcx>, place: &HirPlace<'tcx>) -> String {
+    let name = match place.base {
+        HirPlaceBase::Upvar(upvar_id) => tcx.hir().name(upvar_id.var_path.hir_id).to_string(),
+        _ => bug!("Capture_information should only contain upvars"),
+    };
+    let mut curr_string = name;
+
+    for (i, proj) in place.projections.iter().enumerate() {
+        match proj.kind {
+            HirProjectionKind::Deref => {
+                curr_string = format!("*{}", curr_string);
+            }
+            HirProjectionKind::Field(idx, variant) => match place.ty_before_projection(i).kind() {
+                ty::Adt(def, ..) => {
+                    curr_string = format!(
+                        "{}.{}",
+                        curr_string,
+                        def.variants[variant].fields[idx as usize].ident.name.as_str()
+                    );
+                }
+                ty::Tuple(_) => {
+                    curr_string = format!("{}.{}", curr_string, idx);
+                }
+                _ => {
+                    bug!(
+                        "Field projection applied to a type other than Adt or Tuple: {:?}.",
+                        place.ty_before_projection(i).kind()
+                    )
+                }
+            },
+            proj => bug!("{:?} unexpected because it isn't captured", proj),
+        }
+    }
+
+    curr_string.to_string()
+}
+
 /// Part of `MinCaptureInformationMap`; describes the capture kind (&, &mut, move)
 /// for a particular capture as well as identifying the part of the source code
 /// that triggered this capture to occur.

Diff for: compiler/rustc_mir/src/borrow_check/diagnostics/mod.rs

@@ -103,15 +103,15 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                         let did = did.expect_local();
                         let hir_id = self.infcx.tcx.hir().local_def_id_to_hir_id(did);
 
-                        if let Some((span, name)) =
+                        if let Some((span, hir_place)) =
                             self.infcx.tcx.typeck(did).closure_kind_origins().get(hir_id)
                         {
                             diag.span_note(
                                 *span,
                                 &format!(
                                     "closure cannot be invoked more than once because it moves the \
                                     variable `{}` out of its environment",
-                                    name,
+                                    ty::place_to_string_for_capture(self.infcx.tcx, hir_place)
                                 ),
                             );
                             return;
@@ -127,15 +127,15 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 let did = did.expect_local();
                 let hir_id = self.infcx.tcx.hir().local_def_id_to_hir_id(did);
 
-                if let Some((span, name)) =
+                if let Some((span, hir_place)) =
                     self.infcx.tcx.typeck(did).closure_kind_origins().get(hir_id)
                 {
                     diag.span_note(
                         *span,
                         &format!(
                             "closure cannot be moved more than once as it is not `Copy` due to \
                              moving the variable `{}` out of its environment",
-                            name
+                            ty::place_to_string_for_capture(self.infcx.tcx, hir_place)
                         ),
                     );
                 }

Diff for: compiler/rustc_mir/src/borrow_check/type_check/input_output.rs

@@ -39,10 +39,8 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             user_provided_sig = None;
         } else {
             let typeck_results = self.tcx().typeck(mir_def_id);
-            user_provided_sig = match typeck_results.user_provided_sigs.get(&mir_def_id.to_def_id())
-            {
-                None => None,
-                Some(user_provided_poly_sig) => {
+            user_provided_sig = typeck_results.user_provided_sigs.get(&mir_def_id.to_def_id()).map(
+                |user_provided_poly_sig| {
                     // Instantiate the canonicalized variables from
                     // user-provided signature (e.g., the `_` in the code
                     // above) with fresh variables.
@@ -54,18 +52,16 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                     // Replace the bound items in the fn sig with fresh
                     // variables, so that they represent the view from
                     // "inside" the closure.
-                    Some(
-                        self.infcx
-                            .replace_bound_vars_with_fresh_vars(
-                                body.span,
-                                LateBoundRegionConversionTime::FnCall,
-                                poly_sig,
-                            )
-                            .0,
-                    )
-                }
-            }
-        };
+                    self.infcx
+                        .replace_bound_vars_with_fresh_vars(
+                            body.span,
+                            LateBoundRegionConversionTime::FnCall,
+                            poly_sig,
+                        )
+                        .0
+                },
+            );
+        }
 
         debug!(
             "equate_inputs_and_outputs: normalized_input_tys = {:?}, local_decls = {:?}",

Diff for: compiler/rustc_mir/src/borrow_check/universal_regions.rs

@@ -788,13 +788,13 @@ fn for_each_late_bound_region_defined_on<'tcx>(
     fn_def_id: DefId,
     mut f: impl FnMut(ty::Region<'tcx>),
 ) {
-    if let Some(late_bounds) = tcx.is_late_bound_map(fn_def_id.expect_local()) {
-        for late_bound in late_bounds.iter() {
-            let hir_id = HirId { owner: fn_def_id.expect_local(), local_id: *late_bound };
+    if let Some((owner, late_bounds)) = tcx.is_late_bound_map(fn_def_id.expect_local()) {
+        for &late_bound in late_bounds.iter() {
+            let hir_id = HirId { owner, local_id: late_bound };
             let name = tcx.hir().name(hir_id);
             let region_def_id = tcx.hir().local_def_id(hir_id);
             let liberated_region = tcx.mk_region(ty::ReFree(ty::FreeRegion {
-                scope: fn_def_id,
+                scope: owner.to_def_id(),
                 bound_region: ty::BoundRegionKind::BrNamed(region_def_id.to_def_id(), name),
             }));
             f(liberated_region);

Diff for: compiler/rustc_resolve/src/build_reduced_graph.rs

@@ -115,7 +115,7 @@ impl<'a> Resolver<'a> {
         self.get_module(parent_id)
     }
 
-    crate fn get_module(&mut self, def_id: DefId) -> Module<'a> {
+    pub fn get_module(&mut self, def_id: DefId) -> Module<'a> {
         // If this is a local module, it will be in `module_map`, no need to recalculate it.
         if let Some(def_id) = def_id.as_local() {
             return self.module_map[&def_id];

Diff for: compiler/rustc_resolve/src/diagnostics.rs

@@ -683,7 +683,7 @@ impl<'a> Resolver<'a> {
                     ));
                 }
                 Scope::BuiltinAttrs => {
-                    let res = Res::NonMacroAttr(NonMacroAttrKind::Builtin);
+                    let res = Res::NonMacroAttr(NonMacroAttrKind::Builtin(kw::Empty));
                     if filter_fn(res) {
                         suggestions.extend(
                             BUILTIN_ATTRIBUTES