Rollup of 9 pull requests

RELEASES.md

@@ -69,8 +69,12 @@ These previously stable APIs are now stable in const contexts:
 
 - [`NonNull<T>::replace`](https://doc.rust-lang.org/stable/std/ptr/struct.NonNull.html#method.replace)
 - [`<*mut T>::replace`](https://doc.rust-lang.org/stable/std/primitive.pointer.html#method.replace)
-- [`std::ptr::swap_nonoverlapping`](https://github.com/rust-lang/rust/pull/137280)
-- [`Cell::{replace, get, get_mut, from_mut, as_slice_of_cells}`](https://github.com/rust-lang/rust/pull/137928)
+- [`std::ptr::swap_nonoverlapping`](https://doc.rust-lang.org/stable/std/ptr/fn.swap_nonoverlapping.html)
+- [`Cell::replace`](https://doc.rust-lang.org/stable/std/cell/struct.Cell.html#method.replace)
+- [`Cell::get`](https://doc.rust-lang.org/stable/std/cell/struct.Cell.html#method.get)
+- [`Cell::get_mut`](https://doc.rust-lang.org/stable/std/cell/struct.Cell.html#method.get_mut)
+- [`Cell::from_mut`](https://doc.rust-lang.org/stable/std/cell/struct.Cell.html#method.from_mut)
+- [`Cell::as_slice_of_cells`](https://doc.rust-lang.org/stable/std/cell/struct.Cell.html#method.as_slice_of_cells)
 
 
 <a id="1.88.0-Cargo"></a>

compiler/rustc_borrowck/src/diagnostics/region_errors.rs

@@ -10,7 +10,7 @@ use rustc_hir::def::Res::Def;
 use rustc_hir::def_id::DefId;
 use rustc_hir::intravisit::VisitorExt;
 use rustc_hir::{PolyTraitRef, TyKind, WhereBoundPredicate};
-use rustc_infer::infer::{NllRegionVariableOrigin, RelateParamBound};
+use rustc_infer::infer::{NllRegionVariableOrigin, SubregionOrigin};
 use rustc_middle::bug;
 use rustc_middle::hir::place::PlaceBase;
 use rustc_middle::mir::{AnnotationSource, ConstraintCategory, ReturnConstraint};
@@ -329,7 +329,8 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
                             self.infcx.tcx,
                             type_test.generic_kind.to_ty(self.infcx.tcx),
                         );
-                        let origin = RelateParamBound(type_test_span, generic_ty, None);
+                        let origin =
+                            SubregionOrigin::RelateParamBound(type_test_span, generic_ty, None);
                         self.buffer_error(self.infcx.err_ctxt().construct_generic_bound_failure(
                             self.body.source.def_id().expect_local(),
                             type_test_span,

compiler/rustc_borrowck/src/type_check/constraint_conversion.rs

@@ -3,7 +3,7 @@ use rustc_infer::infer::canonical::QueryRegionConstraints;
 use rustc_infer::infer::outlives::env::RegionBoundPairs;
 use rustc_infer::infer::outlives::obligations::{TypeOutlives, TypeOutlivesDelegate};
 use rustc_infer::infer::region_constraints::{GenericKind, VerifyBound};
-use rustc_infer::infer::{self, InferCtxt, SubregionOrigin};
+use rustc_infer::infer::{InferCtxt, SubregionOrigin};
 use rustc_infer::traits::query::type_op::DeeplyNormalize;
 use rustc_middle::bug;
 use rustc_middle::ty::{
@@ -172,7 +172,7 @@ impl<'a, 'tcx> ConstraintConversion<'a, 'tcx> {
                             ty::Region::new_var(tcx, universal_regions.implicit_region_bound());
                         // we don't actually use this for anything, but
                         // the `TypeOutlives` code needs an origin.
-                        let origin = infer::RelateParamBound(self.span, t1, None);
+                        let origin = SubregionOrigin::RelateParamBound(self.span, t1, None);
                         TypeOutlives::new(
                             &mut *self,
                             tcx,

compiler/rustc_borrowck/src/type_check/input_output.rs

@@ -66,10 +66,9 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 Ty::new_tup(self.tcx(), user_provided_sig.inputs()),
                 args.tupled_upvars_ty(),
                 args.coroutine_captures_by_ref_ty(),
-                self.infcx
-                    .next_region_var(RegionVariableOrigin::MiscVariable(self.body.span), || {
-                        RegionCtxt::Unknown
-                    }),
+                self.infcx.next_region_var(RegionVariableOrigin::Misc(self.body.span), || {
+                    RegionCtxt::Unknown
+                }),
             );
 
             let next_ty_var = || self.infcx.next_ty_var(self.body.span);

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -16,7 +16,7 @@ use rustc_infer::infer::canonical::QueryRegionConstraints;
 use rustc_infer::infer::outlives::env::RegionBoundPairs;
 use rustc_infer::infer::region_constraints::RegionConstraintData;
 use rustc_infer::infer::{
-    BoundRegion, BoundRegionConversionTime, InferCtxt, NllRegionVariableOrigin,
+    BoundRegionConversionTime, InferCtxt, NllRegionVariableOrigin, RegionVariableOrigin,
 };
 use rustc_infer::traits::PredicateObligations;
 use rustc_middle::mir::visit::{NonMutatingUseContext, PlaceContext, Visitor};
@@ -794,7 +794,7 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
                     };
 
                     self.infcx.next_region_var(
-                        BoundRegion(
+                        RegionVariableOrigin::BoundRegion(
                             term.source_info.span,
                             br.kind,
                             BoundRegionConversionTime::FnCall,

compiler/rustc_codegen_ssa/src/codegen_attrs.rs

@@ -446,7 +446,9 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: LocalDefId) -> CodegenFnAttrs {
 
     mixed_export_name_no_mangle_lint_state.lint_if_mixed(tcx);
 
-    // Apply the minimum function alignment here, so that individual backends don't have to.
+    // Apply the minimum function alignment here. This ensures that a function's alignment is
+    // determined by the `-C` flags of the crate it is defined in, not the `-C` flags of the crate
+    // it happens to be codegen'd (or const-eval'd) in.
     codegen_fn_attrs.alignment =
         Ord::max(codegen_fn_attrs.alignment, tcx.sess.opts.unstable_opts.min_function_alignment);
 

compiler/rustc_hir/src/hir.rs

@@ -3141,6 +3141,15 @@ pub enum TraitItemKind<'hir> {
     /// type.
     Type(GenericBounds<'hir>, Option<&'hir Ty<'hir>>),
 }
+impl TraitItemKind<'_> {
+    pub fn descr(&self) -> &'static str {
+        match self {
+            TraitItemKind::Const(..) => "associated constant",
+            TraitItemKind::Fn(..) => "function",
+            TraitItemKind::Type(..) => "associated type",
+        }
+    }
+}
 
 // The bodies for items are stored "out of line", in a separate
 // hashmap in the `Crate`. Here we just record the hir-id of the item
@@ -3202,6 +3211,15 @@ pub enum ImplItemKind<'hir> {
     /// An associated type.
     Type(&'hir Ty<'hir>),
 }
+impl ImplItemKind<'_> {
+    pub fn descr(&self) -> &'static str {
+        match self {
+            ImplItemKind::Const(..) => "associated constant",
+            ImplItemKind::Fn(..) => "function",
+            ImplItemKind::Type(..) => "associated type",
+        }
+    }
+}
 
 /// A constraint on an associated item.
 ///
@@ -4527,6 +4545,16 @@ pub enum ForeignItemKind<'hir> {
     Type,
 }
 
+impl ForeignItemKind<'_> {
+    pub fn descr(&self) -> &'static str {
+        match self {
+            ForeignItemKind::Fn(..) => "function",
+            ForeignItemKind::Static(..) => "static variable",
+            ForeignItemKind::Type => "type",
+        }
+    }
+}
+
 /// A variable captured by a closure.
 #[derive(Debug, Copy, Clone, HashStable_Generic)]
 pub struct Upvar {

compiler/rustc_hir_analysis/src/check/check.rs

@@ -312,7 +312,7 @@ fn check_opaque_meets_bounds<'tcx>(
     // here rather than using ReErased.
     let hidden_ty = tcx.type_of(def_id.to_def_id()).instantiate(tcx, args);
     let hidden_ty = fold_regions(tcx, hidden_ty, |re, _dbi| match re.kind() {
-        ty::ReErased => infcx.next_region_var(RegionVariableOrigin::MiscVariable(span)),
+        ty::ReErased => infcx.next_region_var(RegionVariableOrigin::Misc(span)),
         _ => re,
     });
 

compiler/rustc_hir_analysis/src/check/compare_impl_item.rs

@@ -9,7 +9,7 @@ use rustc_errors::{Applicability, ErrorGuaranteed, MultiSpan, pluralize, struct_
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::intravisit::VisitorExt;
 use rustc_hir::{self as hir, AmbigArg, GenericParamKind, ImplItemKind, intravisit};
-use rustc_infer::infer::{self, InferCtxt, TyCtxtInferExt};
+use rustc_infer::infer::{self, BoundRegionConversionTime, InferCtxt, TyCtxtInferExt};
 use rustc_infer::traits::util;
 use rustc_middle::ty::error::{ExpectedFound, TypeError};
 use rustc_middle::ty::{
@@ -311,7 +311,7 @@ fn compare_method_predicate_entailment<'tcx>(
 
     let unnormalized_impl_sig = infcx.instantiate_binder_with_fresh_vars(
         impl_m_span,
-        infer::HigherRankedType,
+        BoundRegionConversionTime::HigherRankedType,
         tcx.fn_sig(impl_m.def_id).instantiate_identity(),
     );
 
@@ -518,7 +518,7 @@ pub(super) fn collect_return_position_impl_trait_in_trait_tys<'tcx>(
         param_env,
         infcx.instantiate_binder_with_fresh_vars(
             return_span,
-            infer::HigherRankedType,
+            BoundRegionConversionTime::HigherRankedType,
             tcx.fn_sig(impl_m.def_id).instantiate_identity(),
         ),
     );

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -11,7 +11,7 @@ use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::lang_items::LangItem;
 use rustc_hir::{AmbigArg, ItemKind};
 use rustc_infer::infer::outlives::env::OutlivesEnvironment;
-use rustc_infer::infer::{self, InferCtxt, TyCtxtInferExt};
+use rustc_infer::infer::{self, InferCtxt, SubregionOrigin, TyCtxtInferExt};
 use rustc_lint_defs::builtin::SUPERTRAIT_ITEM_SHADOWING_DEFINITION;
 use rustc_macros::LintDiagnostic;
 use rustc_middle::mir::interpret::ErrorHandled;
@@ -231,7 +231,6 @@ fn check_item<'tcx>(tcx: TyCtxt<'tcx>, item: &'tcx hir::Item<'tcx>) -> Result<()
         item.name = ? tcx.def_path_str(def_id)
     );
     crate::collect::lower_item(tcx, item.item_id());
-    crate::collect::reject_placeholder_type_signatures_in_item(tcx, item);
 
     let res = match item.kind {
         // Right now we check that every default trait implementation
@@ -739,7 +738,7 @@ fn ty_known_to_outlive<'tcx>(
         infcx.register_type_outlives_constraint_inner(infer::TypeOutlivesConstraint {
             sub_region: region,
             sup_type: ty,
-            origin: infer::RelateParamBound(DUMMY_SP, ty, None),
+            origin: SubregionOrigin::RelateParamBound(DUMMY_SP, ty, None),
         });
     })
 }
@@ -755,7 +754,11 @@ fn region_known_to_outlive<'tcx>(
     region_b: ty::Region<'tcx>,
 ) -> bool {
     test_region_obligations(tcx, id, param_env, wf_tys, |infcx| {
-        infcx.sub_regions(infer::RelateRegionParamBound(DUMMY_SP, None), region_b, region_a);
+        infcx.sub_regions(
+            SubregionOrigin::RelateRegionParamBound(DUMMY_SP, None),
+            region_b,
+            region_a,
+        );
     })
 }
 

compiler/rustc_hir_analysis/src/coherence/builtin.rs

@@ -10,7 +10,7 @@ use rustc_hir as hir;
 use rustc_hir::ItemKind;
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::lang_items::LangItem;
-use rustc_infer::infer::{self, RegionResolutionError, TyCtxtInferExt};
+use rustc_infer::infer::{self, RegionResolutionError, SubregionOrigin, TyCtxtInferExt};
 use rustc_infer::traits::Obligation;
 use rustc_middle::ty::adjustment::CoerceUnsizedInfo;
 use rustc_middle::ty::print::PrintTraitRefExt as _;
@@ -415,7 +415,7 @@ pub(crate) fn coerce_unsized_info<'tcx>(
     };
     let (source, target, trait_def_id, kind, field_span) = match (source.kind(), target.kind()) {
         (&ty::Ref(r_a, ty_a, mutbl_a), &ty::Ref(r_b, ty_b, mutbl_b)) => {
-            infcx.sub_regions(infer::RelateObjectBound(span), r_b, r_a);
+            infcx.sub_regions(SubregionOrigin::RelateObjectBound(span), r_b, r_a);
             let mt_a = ty::TypeAndMut { ty: ty_a, mutbl: mutbl_a };
             let mt_b = ty::TypeAndMut { ty: ty_b, mutbl: mutbl_b };
             check_mutbl(mt_a, mt_b, &|ty| Ty::new_imm_ref(tcx, r_b, ty))