Auto merge of #88681 - ehuss:duplicate-attributes, r=petrochenkov

[rust.git] / compiler / rustc_typeck / src / collect.rs

diff --git a/compiler/rustc_typeck/src/collect.rs b/compiler/rustc_typeck/src/collect.rs
index de1606a7ed5f07f16f9f8e8b58df2e0a29974a8b..b9db8a6be5916bbc7b000970e6921b7e6e64c393 100644 (file)
--- a/compiler/rustc_typeck/src/collect.rs
+++ b/compiler/rustc_typeck/src/collect.rs
@@ -1990,16 +1990,12 @@ fn predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericPredicates<'_> {
         // prove that the trait applies to the types that were
         // used, and adding the predicate into this list ensures
         // that this is done.
-        let mut span = tcx.def_span(def_id);
-        if tcx.sess.source_map().is_local_span(span) {
-            // `guess_head_span` reads the actual source file from
-            // disk to try to determine the 'head' snippet of the span.
-            // Don't do this for a span that comes from a file outside
-            // of our crate, since this would make our query output
-            // (and overall crate metadata) dependent on the
-            // *current* state of an external file.
-            span = tcx.sess.source_map().guess_head_span(span);
-        }
+        //
+        // We use a DUMMY_SP here as a way to signal trait bounds that come
+        // from the trait itself that *shouldn't* be shown as the source of
+        // an obligation and instead be skipped. Otherwise we'd use
+        // `tcx.def_span(def_id);`
+        let span = rustc_span::DUMMY_SP;
         result.predicates =
             tcx.arena.alloc_from_iter(result.predicates.iter().copied().chain(std::iter::once((
                 ty::TraitRef::identity(tcx, def_id).without_const().to_predicate(tcx),