bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Don't consider !Unpin references as noalias

Browse source 
Such structures may contain self-references, in which case the
same location may be accessible through a pointer that is not
based-on the noalias pointer.

This is still grey area as far as language semantics are concerned,
but checking for !Unpin as an indicator for self-referential
sturctures seems like a good approach for the meantime.
This commit is contained in:
Nikita Popov 2021-03-18 22:44:36 +01:00
parent 08c5ffd4a3
commit c3f9403f59
5 changed files with 82 additions and 4 deletions
Download patch file Download diff file Expand all files Collapse all files

12
compiler/rustc_ty_utils/src/common_traits.rs
View file

@ -18,6 +18,10 @@ fn is_freeze_raw<'tcx>(tcx: TyCtxt<'tcx>, query: ty::ParamEnvAnd<'tcx, Ty<'tcx>>
is_item_raw(tcx, query, LangItem::Freeze)
}
fn is_unpin_raw<'tcx>(tcx: TyCtxt<'tcx>, query: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
is_item_raw(tcx, query, LangItem::Unpin)
}
fn is_item_raw<'tcx>(
tcx: TyCtxt<'tcx>,
query: ty::ParamEnvAnd<'tcx, Ty<'tcx>>,
@ -37,5 +41,11 @@ fn is_item_raw<'tcx>(
}
pub(crate) fn provide(providers: &mut ty::query::Providers) {
*providers = ty::query::Providers { is_copy_raw, is_sized_raw, is_freeze_raw, ..*providers };
*providers = ty::query::Providers {
is_copy_raw,
is_sized_raw,
is_freeze_raw,
is_unpin_raw,
..*providers
};
}