Skip to content

Commit

Permalink
Rollup merge of rust-lang#122172 - compiler-errors:rpitit-collect-ice…
Browse files Browse the repository at this point in the history
…, r=fmease

Don't ICE if we collect no RPITITs unless there are no unification errors

Move an assertion in `collect_return_position_impl_trait_in_trait_tys` to after the `ObligationCtxt::eq` calls, so that we only assert and ICE if we have unification errors.

Fixes rust-lang#121468
  • Loading branch information
matthiaskrgr authored Mar 8, 2024
2 parents 9829ff6 + 07bd05e commit 02b89d1
Show file tree
Hide file tree
Showing 3 changed files with 92 additions and 8 deletions.
15 changes: 7 additions & 8 deletions compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
Original file line number Diff line number Diff line change
Expand Up @@ -521,14 +521,6 @@ pub(super) fn collect_return_position_impl_trait_in_trait_tys<'tcx>(
)
.fold_with(&mut collector);

if !unnormalized_trait_sig.output().references_error() {
debug_assert_ne!(
collector.types.len(),
0,
"expect >1 RPITITs in call to `collect_return_position_impl_trait_in_trait_tys`"
);
}

let trait_sig = ocx.normalize(&misc_cause, param_env, unnormalized_trait_sig);
trait_sig.error_reported()?;
let trait_return_ty = trait_sig.output();
Expand Down Expand Up @@ -647,6 +639,13 @@ pub(super) fn collect_return_position_impl_trait_in_trait_tys<'tcx>(
}
}

if !unnormalized_trait_sig.output().references_error() {
debug_assert!(
!collector.types.is_empty(),
"expect >0 RPITITs in call to `collect_return_position_impl_trait_in_trait_tys`"
);
}

// FIXME: This has the same issue as #108544, but since this isn't breaking
// existing code, I'm not particularly inclined to do the same hack as above
// where we process wf obligations manually. This can be fixed in a forward-
Expand Down
18 changes: 18 additions & 0 deletions tests/ui/impl-trait/in-trait/opaque-and-lifetime-mismatch.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,18 @@
struct Wrapper<'rom>(T);
//~^ ERROR cannot find type `T` in this scope

trait Foo {
fn bar() -> Wrapper<impl Sized>;
//~^ ERROR missing lifetime specifier
//~| ERROR struct takes 0 generic arguments but 1 generic argument was supplied
}

impl Foo for () {
fn bar() -> i32 {
//~^ ERROR method `bar` has an incompatible type for trait
//~| ERROR method `bar` has an incompatible return type for trait
0
}
}

fn main() {}
67 changes: 67 additions & 0 deletions tests/ui/impl-trait/in-trait/opaque-and-lifetime-mismatch.stderr
Original file line number Diff line number Diff line change
@@ -0,0 +1,67 @@
error[E0106]: missing lifetime specifier
--> $DIR/opaque-and-lifetime-mismatch.rs:5:24
|
LL | fn bar() -> Wrapper<impl Sized>;
| ^ expected named lifetime parameter
|
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`, or if you will only have owned values
|
LL | fn bar() -> Wrapper<'static, impl Sized>;
| ++++++++

error[E0412]: cannot find type `T` in this scope
--> $DIR/opaque-and-lifetime-mismatch.rs:1:22
|
LL | struct Wrapper<'rom>(T);
| ^ not found in this scope
|
help: you might be missing a type parameter
|
LL | struct Wrapper<'rom, T>(T);
| +++

error[E0107]: struct takes 0 generic arguments but 1 generic argument was supplied
--> $DIR/opaque-and-lifetime-mismatch.rs:5:17
|
LL | fn bar() -> Wrapper<impl Sized>;
| ^^^^^^^ ---------- help: remove this generic argument
| |
| expected 0 generic arguments
|
note: struct defined here, with 0 generic parameters
--> $DIR/opaque-and-lifetime-mismatch.rs:1:8
|
LL | struct Wrapper<'rom>(T);
| ^^^^^^^

error[E0053]: method `bar` has an incompatible return type for trait
--> $DIR/opaque-and-lifetime-mismatch.rs:11:17
|
LL | fn bar() -> i32 {
| ^^^
| |
| expected `Wrapper<'static>`, found `i32`
| return type in trait

error[E0053]: method `bar` has an incompatible type for trait
--> $DIR/opaque-and-lifetime-mismatch.rs:11:17
|
LL | fn bar() -> i32 {
| ^^^
| |
| expected `Wrapper<'static>`, found `i32`
| help: change the output type to match the trait: `Wrapper<'static>`
|
note: type in trait
--> $DIR/opaque-and-lifetime-mismatch.rs:5:17
|
LL | fn bar() -> Wrapper<impl Sized>;
| ^^^^^^^^^^^^^^^^^^^
= note: expected signature `fn() -> Wrapper<'static>`
found signature `fn() -> i32`

error: aborting due to 5 previous errors

Some errors have detailed explanations: E0053, E0106, E0107, E0412.
For more information about an error, try `rustc --explain E0053`.

0 comments on commit 02b89d1

Please sign in to comment.