Auto merge of rust-lang#114358 - matthiaskrgr:rollup-d810m9e, r=matthiaskrgr

Rollup of 6 pull requests

Successful merges:

 - rust-lang#114178 (Account for macros when suggesting a new let binding)
 - rust-lang#114199 (Don't unsize coerce infer vars in select in new solver)
 - rust-lang#114301 (Don't check unnecessarily that impl trait is RPIT)
 - rust-lang#114314 (Tweaks to `adt_sized_constraint`)
 - rust-lang#114322 (Fix invalid slice coercion suggestion reported in turbofish)
 - rust-lang#114340 ([rustc_attr][nit] Replace `filter` + `is_some` with `map_or`.)

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

Author: bors

compiler/rustc_attr/src/builtin.rs

@@ -28,7 +28,7 @@ pub fn rust_version_symbol() -> Symbol {
 }
 
 pub fn is_builtin_attr(attr: &Attribute) -> bool {
-    attr.is_doc_comment() || attr.ident().filter(|ident| is_builtin_attr_name(ident.name)).is_some()
+    attr.is_doc_comment() || attr.ident().is_some_and(|ident| is_builtin_attr_name(ident.name))
 }
 
 enum AttrError {

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -2133,13 +2133,14 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                         self.current -= 1;
                     }
                     fn visit_expr(&mut self, expr: &hir::Expr<'tcx>) {
-                        if self.span == expr.span {
+                        if self.span == expr.span.source_callsite() {
                             self.found = self.current;
                         }
                         walk_expr(self, expr);
                     }
                 }
                 let source_info = self.body.source_info(location);
+                let proper_span = proper_span.source_callsite();
                 if let Some(scope) = self.body.source_scopes.get(source_info.scope)
                     && let ClearCrossCrate::Set(scope_data) = &scope.local_data
                     && let Some(node) = self.infcx.tcx.hir().find(scope_data.lint_root)

compiler/rustc_hir_analysis/src/astconv/mod.rs

@@ -1462,7 +1462,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                     let traits: Vec<_> =
                         self.probe_traits_that_match_assoc_ty(qself_ty, assoc_ident);
 
-                    // Don't print `TyErr` to the user.
+                    // Don't print `ty::Error` to the user.
                     self.report_ambiguous_associated_type(
                         span,
                         &[qself_ty.to_string()],

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -555,8 +555,8 @@ fn gather_gat_bounds<'tcx, T: TypeFoldable<TyCtxt<'tcx>>>(
     for (region_a, region_a_idx) in &regions {
         // Ignore `'static` lifetimes for the purpose of this lint: it's
         // because we know it outlives everything and so doesn't give meaningful
-        // clues
-        if let ty::ReStatic = **region_a {
+        // clues. Also ignore `ReError`, to avoid knock-down errors.
+        if let ty::ReStatic | ty::ReError(_) = **region_a {
             continue;
         }
         // For each region argument (e.g., `'a` in our example), check for a
@@ -599,8 +599,9 @@ fn gather_gat_bounds<'tcx, T: TypeFoldable<TyCtxt<'tcx>>>(
         // on the GAT itself.
         for (region_b, region_b_idx) in &regions {
             // Again, skip `'static` because it outlives everything. Also, we trivially
-            // know that a region outlives itself.
-            if ty::ReStatic == **region_b || region_a == region_b {
+            // know that a region outlives itself. Also ignore `ReError`, to avoid
+            // knock-down errors.
+            if matches!(**region_b, ty::ReStatic | ty::ReError(_)) || region_a == region_b {
                 continue;
             }
             if region_known_to_outlive(

compiler/rustc_hir_typeck/src/closure.rs

@@ -795,7 +795,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
     /// Converts the types that the user supplied, in case that doing
     /// so should yield an error, but returns back a signature where
-    /// all parameters are of type `TyErr`.
+    /// all parameters are of type `ty::Error`.
     fn error_sig_of_closure(
         &self,
         decl: &hir::FnDecl<'_>,

compiler/rustc_infer/src/infer/error_reporting/mod.rs

@@ -2567,15 +2567,13 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                     None,
                 );
                 if let Some(infer::RelateParamBound(_, t, _)) = origin {
-                    let return_impl_trait =
-                        self.tcx.return_type_impl_trait(generic_param_scope).is_some();
                     let t = self.resolve_vars_if_possible(t);
                     match t.kind() {
                         // We've got:
                         // fn get_later<G, T>(g: G, dest: &mut T) -> impl FnOnce() + '_
                         // suggest:
                         // fn get_later<'a, G: 'a, T>(g: G, dest: &mut T) -> impl FnOnce() + '_ + 'a
-                        ty::Closure(..) | ty::Alias(ty::Opaque, ..) if return_impl_trait => {
+                        ty::Closure(..) | ty::Alias(ty::Opaque, ..) => {
                             new_binding_suggestion(&mut err, type_param_span);
                         }
                         _ => {

compiler/rustc_infer/src/infer/lexical_region_resolve/mod.rs

@@ -942,6 +942,10 @@ impl<'cx, 'tcx> LexicalResolver<'cx, 'tcx> {
         generic_ty: Ty<'tcx>,
         min: ty::Region<'tcx>,
     ) -> bool {
+        if let ty::ReError(_) = *min {
+            return true;
+        }
+
         match bound {
             VerifyBound::IfEq(verify_if_eq_b) => {
                 let verify_if_eq_b = var_values.normalize(self.region_rels.tcx, *verify_if_eq_b);

compiler/rustc_middle/src/query/mod.rs

@@ -706,7 +706,7 @@ rustc_queries! {
         separate_provide_extern
     }
 
-    query adt_sized_constraint(key: DefId) -> &'tcx [Ty<'tcx>] {
+    query adt_sized_constraint(key: DefId) -> ty::EarlyBinder<&'tcx ty::List<Ty<'tcx>>> {
         desc { |tcx| "computing `Sized` constraints for `{}`", tcx.def_path_str(key) }
     }
 

compiler/rustc_middle/src/ty/adt.rs

@@ -562,18 +562,10 @@ impl<'tcx> AdtDef<'tcx> {
         tcx.adt_destructor(self.did())
     }
 
-    /// Returns a list of types such that `Self: Sized` if and only
-    /// if that type is `Sized`, or `TyErr` if this type is recursive.
-    ///
-    /// Oddly enough, checking that the sized-constraint is `Sized` is
-    /// actually more expressive than checking all members:
-    /// the `Sized` trait is inductive, so an associated type that references
-    /// `Self` would prevent its containing ADT from being `Sized`.
-    ///
-    /// Due to normalization being eager, this applies even if
-    /// the associated type is behind a pointer (e.g., issue #31299).
-    pub fn sized_constraint(self, tcx: TyCtxt<'tcx>) -> ty::EarlyBinder<&'tcx [Ty<'tcx>]> {
-        ty::EarlyBinder::bind(tcx.adt_sized_constraint(self.did()))
+    /// Returns a list of types such that `Self: Sized` if and only if that
+    /// type is `Sized`, or `ty::Error` if this type has a recursive layout.
+    pub fn sized_constraint(self, tcx: TyCtxt<'tcx>) -> ty::EarlyBinder<&'tcx ty::List<Ty<'tcx>>> {
+        tcx.adt_sized_constraint(self.did())
     }
 }
 

compiler/rustc_middle/src/ty/context.rs

@@ -50,9 +50,7 @@ use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, LOCAL_CRATE};
 use rustc_hir::definitions::Definitions;
 use rustc_hir::intravisit::Visitor;
 use rustc_hir::lang_items::LangItem;
-use rustc_hir::{
-    Constness, ExprKind, HirId, ImplItemKind, ItemKind, Node, TraitCandidate, TraitItemKind,
-};
+use rustc_hir::{Constness, HirId, Node, TraitCandidate};
 use rustc_index::IndexVec;
 use rustc_macros::HashStable;
 use rustc_query_system::dep_graph::DepNodeIndex;
@@ -1077,31 +1075,6 @@ impl<'tcx> TyCtxt<'tcx> {
         return None;
     }
 
-    pub fn return_type_impl_trait(self, scope_def_id: LocalDefId) -> Option<(Ty<'tcx>, Span)> {
-        // `type_of()` will fail on these (#55796, #86483), so only allow `fn`s or closures.
-        match self.hir().get_by_def_id(scope_def_id) {
-            Node::Item(&hir::Item { kind: ItemKind::Fn(..), .. }) => {}
-            Node::TraitItem(&hir::TraitItem { kind: TraitItemKind::Fn(..), .. }) => {}
-            Node::ImplItem(&hir::ImplItem { kind: ImplItemKind::Fn(..), .. }) => {}
-            Node::Expr(&hir::Expr { kind: ExprKind::Closure { .. }, .. }) => {}
-            _ => return None,
-        }
-
-        let ret_ty = self.type_of(scope_def_id).instantiate_identity();
-        match ret_ty.kind() {
-            ty::FnDef(_, _) => {
-                let sig = ret_ty.fn_sig(self);
-                let output = self.erase_late_bound_regions(sig.output());
-                output.is_impl_trait().then(|| {
-                    let hir_id = self.hir().local_def_id_to_hir_id(scope_def_id);
-                    let fn_decl = self.hir().fn_decl_by_hir_id(hir_id).unwrap();
-                    (output, fn_decl.output.span())
-                })
-            }
-            _ => None,
-        }
-    }
-
     /// Checks if the bound region is in Impl Item.
     pub fn is_bound_region_in_impl_item(self, suitable_region_binding_scope: LocalDefId) -> bool {
         let container_id = self.parent(suitable_region_binding_scope.to_def_id());