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

Disable dyn* upcasting

Browse source
This commit is contained in:
Michael Goulet 2022-11-19 04:48:01 +00:00
parent 70f8737b2f
commit c620a972f3
7 changed files with 75 additions and 35 deletions
Download patch file Download diff file Expand all files Collapse all files

4
compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
View file

@ -776,9 +776,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
match (source.kind(), target.kind()) {
// Trait+Kx+'a -> Trait+Ky+'b (upcasts).
(&ty::Dynamic(ref data_a, _, dyn_a), &ty::Dynamic(ref data_b, _, dyn_b))
if dyn_a == dyn_b =>
{
(&ty::Dynamic(ref data_a, _, ty::Dyn), &ty::Dynamic(ref data_b, _, ty::Dyn)) => {
// Upcast coercions permit several things:
//
// 1. Dropping auto traits, e.g., `Foo + Send` to `Foo`

9
compiler/rustc_trait_selection/src/traits/select/confirmation.rs
View file

@ -803,9 +803,10 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
let upcast_trait_ref;
match (source.kind(), target.kind()) {
// TraitA+Kx+'a -> TraitB+Ky+'b (trait upcasting coercion).
(&ty::Dynamic(ref data_a, r_a, repr_a), &ty::Dynamic(ref data_b, r_b, repr_b))
if repr_a == repr_b =>
{
(
&ty::Dynamic(ref data_a, r_a, repr_a @ ty::Dyn),
&ty::Dynamic(ref data_b, r_b, ty::Dyn),
) => {
// See `assemble_candidates_for_unsizing` for more info.
// We already checked the compatibility of auto traits within `assemble_candidates_for_unsizing`.
let principal_a = data_a.principal().unwrap();
@ -831,7 +832,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
.map(ty::Binder::dummy),
);
let existential_predicates = tcx.mk_poly_existential_predicates(iter);
let source_trait = tcx.mk_dynamic(existential_predicates, r_b, repr_b);
let source_trait = tcx.mk_dynamic(existential_predicates, r_b, repr_a);
// Require that the traits involved in this upcast are **equal**;
// only the **lifetime bound** is changed.