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Auto merge of #107038 - compiler-errors:dont-wfcheck-non-local-rpit, r=oli-obk

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Don't wf-check non-local RPITs

We were using `ty::is_impl_trait_defn(..).is_none()` to check if we need to add WF obligations for an opaque type.

This is *supposed* to be checking if the type is a TAIT, since RPITs' wfness is implied by wf checking its parent item, but since `is_impl_trait_defn` returns `None` for non-local RPIT and async futures, we unnecessarily consider wf predicates for an RPIT if it is coming from a foreign crate.

Fixes #107036

r? `@oli-obk` but feel free to reassign
This commit is contained in:
bors 2023-01-19 16:49:06 +00:00
commit 4c83bd03a9
10 changed files with 61 additions and 3 deletions
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2
compiler/rustc_hir_analysis/src/astconv/mod.rs
View file

@ -2602,7 +2602,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
match path.res {
Res::Def(DefKind::OpaqueTy | DefKind::ImplTraitPlaceholder, did) => {
// Check for desugared `impl Trait`.
assert!(ty::is_impl_trait_defn(tcx, did).is_none());
assert!(tcx.is_type_alias_impl_trait(did));
let item_segment = path.segments.split_last().unwrap();
self.prohibit_generics(item_segment.1.iter(), |err| {
err.note("`impl Trait` types can't have type parameters");

11
compiler/rustc_hir_analysis/src/collect.rs
View file

@ -76,6 +76,7 @@ pub fn provide(providers: &mut Providers) {
is_foreign_item,
generator_kind,
collect_mod_item_types,
is_type_alias_impl_trait,
..*providers
};
}
@ -1537,3 +1538,13 @@ fn generator_kind(tcx: TyCtxt<'_>, def_id: DefId) -> Option<hir::GeneratorKind>
_ => bug!("generator_kind applied to non-local def-id {:?}", def_id),
}
}
fn is_type_alias_impl_trait<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> bool {
match tcx.hir().get_if_local(def_id) {
Some(Node::Item(hir::Item { kind: hir::ItemKind::OpaqueTy(opaque), .. })) => {
matches!(opaque.origin, hir::OpaqueTyOrigin::TyAlias)
}
Some(_) => bug!("tried getting opaque_ty_origin for non-opaque: {:?}", def_id),
_ => bug!("tried getting opaque_ty_origin for non-local def-id {:?}", def_id),
}
}