Auto merge of #106129 - compiler-errors:compare_method-tweaks, r=BoxyUwU

Some `compare_method` tweaks

1. Make some of the comparison functions' names more regular
2. Reduce pub scope of some of the things in `compare_method`
~3. Remove some unnecessary opaque type handling code -- `InferCtxt` already is in a mode that doesn't define opaque types~
  * moved to a different PR
4. Bubble up `ErrorGuaranteed` for region constraint errors in `compare_method` - Improves a redundant error message in one unit test.
5. Move the `compare_method` module to have a more general name, since it's more like `compare_impl_item` :)
6. Rename `collect_trait_impl_trait_tys`

3 files changed, 11 insertions, 6 deletions

diff --git a/compiler/rustc_infer/src/infer/error_reporting/mod.rs b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
index e5823660e3f..7222eb77682 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/mod.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
@@ -1836,7 +1836,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
 
         // In some (most?) cases cause.body_id points to actual body, but in some cases
         // it's an actual definition. According to the comments (e.g. in
-        // rustc_hir_analysis/check/compare_method.rs:compare_predicate_entailment) the latter
+        // rustc_hir_analysis/check/compare_impl_item.rs:compare_predicate_entailment) the latter
         // is relied upon by some other code. This might (or might not) need cleanup.
         let body_owner_def_id =
             self.tcx.hir().opt_local_def_id(cause.body_id).unwrap_or_else(|| {
diff --git a/compiler/rustc_infer/src/infer/mod.rs b/compiler/rustc_infer/src/infer/mod.rs
index a9ef91db059..b17a465eb38 100644
--- a/compiler/rustc_infer/src/infer/mod.rs
+++ b/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(|| {
-            self.tcx.sess.delay_span_bug(rustc_span::DUMMY_SP, "error should have been emitted")
-        })
+        if errors.is_empty() {
+            Ok(())
+        } else {
+            Err(self
+                .tcx
+                .sess
+                .delay_span_bug(rustc_span::DUMMY_SP, "error should have been emitted"))
+        }
     }
 
     // [Note-Type-error-reporting]
diff --git a/compiler/rustc_infer/src/infer/outlives/obligations.rs b/compiler/rustc_infer/src/infer/outlives/obligations.rs
index 47bd1564f08..f71c39dc0d2 100644
--- a/compiler/rustc_infer/src/infer/outlives/obligations.rs
+++ b/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,