Auto merge of #113690 - aliemjay:opaque-defined-by-trait, r=compiler-errors

allow opaques to be defined by trait queries, again

This basically reverts #112963.

Moreover, all call-sites of `enter_canonical_trait_query` can now define opaque types, see the ui test `defined-by-user-annotation.rs`.

Fixes #113689

r? `@compiler-errors` `@oli-obk`

1 files changed, 6 insertions, 5 deletions

diff --git a/compiler/rustc_trait_selection/src/infer.rs b/compiler/rustc_trait_selection/src/infer.rs
index 312bd38178f..6efc1e7302c 100644
--- a/compiler/rustc_trait_selection/src/infer.rs
+++ b/compiler/rustc_trait_selection/src/infer.rs
@@ -1,5 +1,5 @@
 use crate::traits::query::evaluate_obligation::InferCtxtExt as _;
-use crate::traits::{self, ObligationCtxt};
+use crate::traits::{self, DefiningAnchor, ObligationCtxt};
 
 use rustc_hir::def_id::DefId;
 use rustc_hir::lang_items::LangItem;
@@ -80,7 +80,7 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> {
 
 pub trait InferCtxtBuilderExt<'tcx> {
     fn enter_canonical_trait_query<K, R>(
-        &mut self,
+        self,
         canonical_key: &Canonical<'tcx, K>,
         operation: impl FnOnce(&ObligationCtxt<'_, 'tcx>, K) -> Result<R, NoSolution>,
     ) -> Result<CanonicalQueryResponse<'tcx, R>, NoSolution>
@@ -108,7 +108,7 @@ impl<'tcx> InferCtxtBuilderExt<'tcx> for InferCtxtBuilder<'tcx> {
     /// have `'tcx` be free on this function so that we can talk about
     /// `K: TypeFoldable<TyCtxt<'tcx>>`.)
     fn enter_canonical_trait_query<K, R>(
-        &mut self,
+        self,
         canonical_key: &Canonical<'tcx, K>,
         operation: impl FnOnce(&ObligationCtxt<'_, 'tcx>, K) -> Result<R, NoSolution>,
     ) -> Result<CanonicalQueryResponse<'tcx, R>, NoSolution>
@@ -117,8 +117,9 @@ impl<'tcx> InferCtxtBuilderExt<'tcx> for InferCtxtBuilder<'tcx> {
         R: Debug + TypeFoldable<TyCtxt<'tcx>>,
         Canonical<'tcx, QueryResponse<'tcx, R>>: ArenaAllocatable<'tcx>,
     {
-        let (infcx, key, canonical_inference_vars) =
-            self.build_with_canonical(DUMMY_SP, canonical_key);
+        let (infcx, key, canonical_inference_vars) = self
+            .with_opaque_type_inference(DefiningAnchor::Bubble)
+            .build_with_canonical(DUMMY_SP, canonical_key);
         let ocx = ObligationCtxt::new(&infcx);
         let value = operation(&ocx, key)?;
         ocx.make_canonicalized_query_response(canonical_inference_vars, value)