bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Compute variances for lazy type aliases

Browse source
This commit is contained in:
León Orell Valerian Liehr 2023-08-03 01:03:31 +02:00
parent 8131b9774e
commit 263a0dec60
No known key found for this signature in database
GPG key ID: D17A07215F68E713
7 changed files with 109 additions and 13 deletions
Download patch file Download diff file Expand all files Collapse all files

26
compiler/rustc_hir_analysis/src/check/wfcheck.rs
View file

@ -245,13 +245,14 @@ fn check_item<'tcx>(tcx: TyCtxt<'tcx>, item: &'tcx hir::Item<'tcx>) {
}
// `ForeignItem`s are handled separately.
hir::ItemKind::ForeignMod { .. } => {}
hir::ItemKind::TyAlias(hir_ty, ..) => {
hir::ItemKind::TyAlias(hir_ty, ast_generics) => {
if tcx.features().lazy_type_alias
|| tcx.type_of(item.owner_id).skip_binder().has_opaque_types()
{
// Bounds of lazy type aliases and of eager ones that contain opaque types are respected.
// E.g: `type X = impl Trait;`, `type X = (impl Trait, Y);`.
check_item_type(tcx, def_id, hir_ty.span, UnsizedHandling::Allow);
check_variances_for_type_defn(tcx, item, ast_generics);
}
}
_ => {}
@ -1700,10 +1701,27 @@ fn check_variances_for_type_defn<'tcx>(
hir_generics: &hir::Generics<'_>,
) {
let identity_args = ty::GenericArgs::identity_for_item(tcx, item.owner_id);
for field in tcx.adt_def(item.owner_id).all_fields() {
if field.ty(tcx, identity_args).references_error() {
return;
match item.kind {
ItemKind::Enum(..) | ItemKind::Struct(..) | ItemKind::Union(..) => {
for field in tcx.adt_def(item.owner_id).all_fields() {
if field.ty(tcx, identity_args).references_error() {
return;
}
}
}
ItemKind::TyAlias(..) => {
let ty = tcx.type_of(item.owner_id).instantiate_identity();
if tcx.features().lazy_type_alias || ty.has_opaque_types() {
if ty.references_error() {
return;
}
} else {
bug!();
}
}
_ => bug!(),
}
let ty_predicates = tcx.predicates_of(item.owner_id);