nordic-dev.net/rust
nordic-dev.net/rust
2
0
Fork 0
mirror of https://github.com/rust-lang/rust.git synced 2024-11-22 14:55:26 +00:00
Code Issues Packages Projects Releases Wiki Activity

ignore bivariant regions in opaque types

Browse Source
This commit is contained in:
Ali MJ Al-Nasrawy 2023-03-03 06:26:01 +03:00
parent 9d74bff829
commit 10da7710cd
3 changed files with 32 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
compiler/rustc_borrowck/src/region_infer/mod.rs
View File

@ -1097,6 +1097,36 @@ impl<'tcx> RegionInferenceContext<'tcx> {
) -> Option<ClosureOutlivesSubject<'tcx>> {
let tcx = infcx.tcx;
// Opaque types' substs may include useless lifetimes.
// We will replace them with ReStatic.
struct OpaqueFolder<'tcx> {
tcx: TyCtxt<'tcx>,
}
impl<'tcx> ty::TypeFolder<TyCtxt<'tcx>> for OpaqueFolder<'tcx> {
fn interner(&self) -> TyCtxt<'tcx> {
self.tcx
}
fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx> {
use ty::TypeSuperFoldable as _;
let tcx = self.tcx;
let &ty::Alias(ty::Opaque, ty::AliasTy { substs, def_id, .. }) = t.kind() else {
return t.super_fold_with(self);
};
let substs =
std::iter::zip(substs, tcx.variances_of(def_id)).map(|(arg, v)| {
match (arg.unpack(), v) {
(ty::GenericArgKind::Lifetime(_), ty::Bivariant) => {
tcx.lifetimes.re_static.into()
}
_ => arg.fold_with(self),
}
});
tcx.mk_opaque(def_id, tcx.mk_substs_from_iter(substs))
}
}
let ty = ty.fold_with(&mut OpaqueFolder { tcx });
let ty = tcx.fold_regions(ty, |r, _depth| {
let r_vid = self.to_region_vid(r);
let r_scc = self.constraint_sccs.scc(r_vid);

4
tests/ui/nll/closure-requirements/type-test-subject-opaque-2.rs
View File

@ -1,5 +1,5 @@
// check-fail
// known-bug: #107516
// Resgression test for #107516.
// check-pass
fn iter1<'a: 'a>() -> impl Iterator<Item = &'static str> {
None.into_iter()

18
tests/ui/nll/closure-requirements/type-test-subject-opaque-2.stderr
View File

@ -1,18 +0,0 @@
error[E0310]: the opaque type `iter1<'_>::{opaque#0}` may not live long enough
--> $DIR/type-test-subject-opaque-2.rs:15:16
|
LL | let _ = || Bivar(iter1());
| ^^^^^^^^^^^^^^
|
= help: consider adding an explicit lifetime bound `iter1<'_>::{opaque#0}: 'static`...
= note: ...so that the type `impl Iterator<Item = &'static str>` will meet its required lifetime bounds
error: `iter2<'_>::{opaque#0}<'_>` does not live long enough
--> $DIR/type-test-subject-opaque-2.rs:16:16
|
LL | let _ = || Bivar(iter2());
| ^^^^^^^^^^^^^^
error: aborting due to 2 previous errors
For more information about this error, try `rustc --explain E0310`.