bjoernager/rust
bjoernager/rust
1
Fork 0
Code Issues Pull requests Activity

Add AliasKind::Weak for type aliases.

Browse source 
Only use it when the type alias contains an opaque type.

Also does wf-checking on such type aliases.
This commit is contained in:
Oli Scherer 2023-03-07 12:03:11 +00:00
parent 4fdd07fe88
commit f3b7dd6388
86 changed files with 474 additions and 199 deletions
Download patch file Download diff file Expand all files Collapse all files

14
compiler/rustc_hir_analysis/src/astconv/mod.rs
View file

@ -1458,7 +1458,19 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
item_segment: &hir::PathSegment<'_>,
) -> Ty<'tcx> {
let substs = self.ast_path_substs_for_ty(span, did, item_segment);
self.tcx().at(span).type_of(did).subst(self.tcx(), substs)
let ty = self.tcx().at(span).type_of(did);
if matches!(self.tcx().def_kind(did), DefKind::TyAlias)
&& ty.skip_binder().has_opaque_types()
{
// Type aliases referring to types that contain opaque types (but aren't just directly
// referencing a single opaque type) get encoded as a type alias that normalization will
// then actually instantiate the where bounds of.
let alias_ty = self.tcx().mk_alias_ty(did, substs);
self.tcx().mk_alias(ty::Weak, alias_ty)
} else {
ty.subst(self.tcx(), substs)
}
}
fn conv_object_ty_poly_trait_ref(