borrowck: use implied bounds from impl header

Author: aliemjay

compiler/rustc_borrowck/src/type_check/free_region_relations.rs

@@ -1,13 +1,14 @@
 use rustc_data_structures::frozen::Frozen;
 use rustc_data_structures::transitive_relation::{TransitiveRelation, TransitiveRelationBuilder};
+use rustc_hir::def::DefKind;
 use rustc_infer::infer::canonical::QueryRegionConstraints;
 use rustc_infer::infer::outlives;
 use rustc_infer::infer::outlives::env::RegionBoundPairs;
 use rustc_infer::infer::region_constraints::GenericKind;
 use rustc_infer::infer::InferCtxt;
 use rustc_middle::mir::ConstraintCategory;
 use rustc_middle::traits::query::OutlivesBound;
-use rustc_middle::ty::{self, RegionVid, Ty};
+use rustc_middle::ty::{self, DefIdTree as _, RegionVid, Ty};
 use rustc_trait_selection::traits::query::type_op::{self, TypeOp};
 use std::rc::Rc;
 use type_op::TypeOpOutput;
@@ -218,7 +219,10 @@ impl<'tcx> UniversalRegionRelationsBuilder<'_, 'tcx> {
     }
 
     pub(crate) fn create(mut self) -> CreateResult<'tcx> {
-        let span = self.infcx.tcx.def_span(self.universal_regions.defining_ty.def_id());
+        let tcx = self.infcx.tcx;
+        let defining_ty_def_id = self.universal_regions.defining_ty.def_id();
+        let span = self.infcx.tcx.def_span(defining_ty_def_id);
+
         let unnormalized_input_output_tys = self
             .universal_regions
             .unnormalized_input_tys
@@ -236,7 +240,7 @@ impl<'tcx> UniversalRegionRelationsBuilder<'_, 'tcx> {
         //   the `relations` is built.
         let mut normalized_inputs_and_output =
             Vec::with_capacity(self.universal_regions.unnormalized_input_tys.len() + 1);
-        let constraint_sets: Vec<_> = unnormalized_input_output_tys
+        let mut constraint_sets: Vec<_> = unnormalized_input_output_tys
             .flat_map(|ty| {
                 debug!("build: input_or_output={:?}", ty);
                 // We add implied bounds from both the unnormalized and normalized ty.
@@ -247,10 +251,7 @@ impl<'tcx> UniversalRegionRelationsBuilder<'_, 'tcx> {
                     .and(type_op::normalize::Normalize::new(ty))
                     .fully_perform(self.infcx)
                     .unwrap_or_else(|_| {
-                        self.infcx
-                            .tcx
-                            .sess
-                            .delay_span_bug(span, &format!("failed to normalize {:?}", ty));
+                        tcx.sess.delay_span_bug(span, &format!("failed to normalize {ty:?}"));
                         TypeOpOutput {
                             output: self.infcx.tcx.ty_error(),
                             constraints: None,
@@ -276,6 +277,25 @@ impl<'tcx> UniversalRegionRelationsBuilder<'_, 'tcx> {
             })
             .collect();
 
+        // Add implied bounds from impl header.
+        if let DefKind::AssocFn = tcx.def_kind(defining_ty_def_id) {
+            for ty in tcx.assumed_wf_types(tcx.parent(defining_ty_def_id)) {
+                let Ok(TypeOpOutput { output: norm_ty, constraints, .. }) = self
+                    .param_env
+                    .and(type_op::normalize::Normalize::new(ty))
+                    .fully_perform(self.infcx)
+                else {
+                    tcx.sess.delay_span_bug(span, &format!("failed to normalize {ty:?}"));
+                    continue;
+                };
+
+                // We currently add implied bounds from the normalized ty only.
+                // This is more conservative and matches wfcheck behavior.
+                self.add_implied_bounds(norm_ty);
+                constraint_sets.extend(constraints);
+            }
+        }
+
         // Insert the facts we know from the predicates. Why? Why not.
         let param_env = self.param_env;
         self.add_outlives_bounds(outlives::explicit_outlives_bounds(param_env));

library/std/src/collections/hash/map.rs

@@ -3051,8 +3051,8 @@ where
 #[stable(feature = "hash_extend_copy", since = "1.4.0")]
 impl<'a, K, V, S> Extend<(&'a K, &'a V)> for HashMap<K, V, S>
 where
-    K: Eq + Hash + Copy + 'a,
-    V: Copy + 'a,
+    K: Eq + Hash + Copy,
+    V: Copy,
     S: BuildHasher,
 {
     #[inline]