Bubble up ErrorGuaranteed from region constraints in method item compare

compiler/rustc_hir_analysis/src/check/check.rs

@@ -468,7 +468,7 @@ fn check_opaque_meets_bounds<'tcx>(
         // Can have different predicates to their defining use
         hir::OpaqueTyOrigin::TyAlias => {
             let outlives_environment = OutlivesEnvironment::new(param_env);
-            infcx.check_region_obligations_and_report_errors(
+            let _ = infcx.check_region_obligations_and_report_errors(
                 defining_use_anchor,
                 &outlives_environment,
             );

compiler/rustc_hir_analysis/src/check/compare_method.rs

@@ -589,7 +589,7 @@ pub fn collect_trait_impl_trait_tys<'tcx>(
     infcx.check_region_obligations_and_report_errors(
         impl_m.def_id.expect_local(),
         &outlives_environment,
-    );
+    )?;
 
     let mut collected_tys = FxHashMap::default();
     for (def_id, (ty, substs)) in collector.types {
@@ -1617,9 +1617,9 @@ pub(crate) fn compare_impl_const_raw(
         return Err(infcx.err_ctxt().report_fulfillment_errors(&errors, None));
     }
 
-    // FIXME return `ErrorReported` if region obligations error?
     let outlives_environment = OutlivesEnvironment::new(param_env);
-    infcx.check_region_obligations_and_report_errors(impl_const_item_def, &outlives_environment);
+    infcx.check_region_obligations_and_report_errors(impl_const_item_def, &outlives_environment)?;
+
     Ok(())
 }
 
@@ -1730,7 +1730,7 @@ fn compare_type_predicate_entailment<'tcx>(
     infcx.check_region_obligations_and_report_errors(
         impl_ty.def_id.expect_local(),
         &outlives_environment,
-    );
+    )?;
 
     Ok(())
 }
@@ -1944,7 +1944,7 @@ pub fn check_type_bounds<'tcx>(
     infcx.check_region_obligations_and_report_errors(
         impl_ty.def_id.expect_local(),
         &outlives_environment,
-    );
+    )?;
 
     let constraints = infcx.inner.borrow_mut().opaque_type_storage.take_opaque_types();
     for (key, value) in constraints {

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -115,7 +115,7 @@ pub(super) fn enter_wf_checking_ctxt<'tcx, F>(
     let outlives_environment =
         OutlivesEnvironment::with_bounds(param_env, Some(infcx), implied_bounds);
 
-    infcx.check_region_obligations_and_report_errors(body_def_id, &outlives_environment);
+    let _ = infcx.check_region_obligations_and_report_errors(body_def_id, &outlives_environment);
 }
 
 fn check_well_formed(tcx: TyCtxt<'_>, def_id: hir::OwnerId) {

compiler/rustc_hir_analysis/src/coherence/builtin.rs

@@ -325,7 +325,7 @@ fn visit_implementation_of_dispatch_from_dyn(tcx: TyCtxt<'_>, impl_did: LocalDef
 
                 // Finally, resolve all regions.
                 let outlives_env = OutlivesEnvironment::new(param_env);
-                infcx.check_region_obligations_and_report_errors(impl_did, &outlives_env);
+                let _ = infcx.check_region_obligations_and_report_errors(impl_did, &outlives_env);
             }
         }
         _ => {
@@ -565,7 +565,7 @@ pub fn coerce_unsized_info<'tcx>(tcx: TyCtxt<'tcx>, impl_did: DefId) -> CoerceUn
 
     // Finally, resolve all regions.
     let outlives_env = OutlivesEnvironment::new(param_env);
-    infcx.check_region_obligations_and_report_errors(impl_did, &outlives_env);
+    let _ = infcx.check_region_obligations_and_report_errors(impl_did, &outlives_env);
 
     CoerceUnsizedInfo { custom_kind: kind }
 }

compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs

@@ -182,7 +182,7 @@ fn get_impl_substs(
 
     let implied_bounds = infcx.implied_bounds_tys(param_env, impl1_hir_id, assumed_wf_types);
     let outlives_env = OutlivesEnvironment::with_bounds(param_env, Some(infcx), implied_bounds);
-    infcx.check_region_obligations_and_report_errors(impl1_def_id, &outlives_env);
+    let _ = infcx.check_region_obligations_and_report_errors(impl1_def_id, &outlives_env);
     let Ok(impl2_substs) = infcx.fully_resolve(impl2_substs) else {
         let span = tcx.def_span(impl1_def_id);
         tcx.sess.emit_err(SubstsOnOverriddenImpl { span });

compiler/rustc_infer/src/infer/mod.rs

@@ -1693,7 +1693,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
         &self,
         generic_param_scope: LocalDefId,
         outlives_env: &OutlivesEnvironment<'tcx>,
-    ) -> Option<ErrorGuaranteed> {
+    ) -> Result<(), ErrorGuaranteed> {
         let errors = self.resolve_regions(outlives_env);
 
         if let None = self.tainted_by_errors() {
@@ -1705,9 +1705,14 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
             self.report_region_errors(generic_param_scope, &errors);
         }
 
-        (!errors.is_empty()).then(|| {
+        if errors.is_empty() {
-            self.tcx.sess.delay_span_bug(rustc_span::DUMMY_SP, "error should have been emitted")
+            Ok(())
-        })
+        } else {
+            Err(self
+                .tcx
+                .sess
+                .delay_span_bug(rustc_span::DUMMY_SP, "error should have been emitted"))
+        }
     }
 
     // [Note-Type-error-reporting]

compiler/rustc_infer/src/infer/outlives/obligations.rs

@@ -178,7 +178,7 @@ impl<'tcx> InferCtxt<'tcx> {
         &self,
         generic_param_scope: LocalDefId,
         outlives_env: &OutlivesEnvironment<'tcx>,
-    ) -> Option<ErrorGuaranteed> {
+    ) -> Result<(), ErrorGuaranteed> {
         self.process_registered_region_obligations(
             outlives_env.region_bound_pairs(),
             outlives_env.param_env,

src/test/ui/generic-associated-types/impl_bounds.rs

@@ -15,7 +15,6 @@ impl<T> Foo for Fooy<T> {
     //~^ ERROR impl has stricter requirements than trait
     type B<'a, 'b> = (&'a(), &'b ()) where 'b: 'a;
     //~^ ERROR impl has stricter requirements than trait
-    //~| ERROR lifetime bound not satisfied
     type C = String where Self: Copy;
     //~^ ERROR the trait bound `T: Copy` is not satisfied
     fn d() where Self: Copy {}

src/test/ui/generic-associated-types/impl_bounds.stderr

@@ -16,28 +16,8 @@ LL |     type B<'a, 'b> where 'a: 'b;
 LL |     type B<'a, 'b> = (&'a(), &'b ()) where 'b: 'a;
    |                                                ^^ impl has extra requirement `'b: 'a`
 
-error[E0478]: lifetime bound not satisfied
-  --> $DIR/impl_bounds.rs:16:22
-   |
-LL |     type B<'a, 'b> where 'a: 'b;
-   |     -------------- definition of `B` from trait
-...
-LL |     type B<'a, 'b> = (&'a(), &'b ()) where 'b: 'a;
-   |                      ^^^^^^^^^^^^^^^             - help: try copying this clause from the trait: `, 'a: 'b`
-   |
-note: lifetime parameter instantiated with the lifetime `'a` as defined here
-  --> $DIR/impl_bounds.rs:16:12
-   |
-LL |     type B<'a, 'b> = (&'a(), &'b ()) where 'b: 'a;
-   |            ^^
-note: but lifetime parameter must outlive the lifetime `'b` as defined here
-  --> $DIR/impl_bounds.rs:16:16
-   |
-LL |     type B<'a, 'b> = (&'a(), &'b ()) where 'b: 'a;
-   |                ^^
-
 error[E0277]: the trait bound `T: Copy` is not satisfied
-  --> $DIR/impl_bounds.rs:19:33
+  --> $DIR/impl_bounds.rs:18:33
    |
 LL |     type C = String where Self: Copy;
    |                                 ^^^^ the trait `Copy` is not implemented for `T`
@@ -62,7 +42,7 @@ LL | impl<T: std::marker::Copy> Foo for Fooy<T> {
    |       +++++++++++++++++++
 
 error[E0277]: the trait bound `T: Copy` is not satisfied
-  --> $DIR/impl_bounds.rs:21:24
+  --> $DIR/impl_bounds.rs:20:24
    |
 LL |     fn d() where Self: Copy {}
    |                        ^^^^ the trait `Copy` is not implemented for `T`
@@ -86,7 +66,7 @@ help: consider restricting type parameter `T`
 LL | impl<T: std::marker::Copy> Foo for Fooy<T> {
    |       +++++++++++++++++++
 
-error: aborting due to 5 previous errors
+error: aborting due to 4 previous errors
 
-Some errors have detailed explanations: E0276, E0277, E0478.
+Some errors have detailed explanations: E0276, E0277.
 For more information about an error, try `rustc --explain E0276`.