diff options
| -rw-r--r-- | compiler/rustc_const_eval/src/util/compare_types.rs | 15 | ||||
| -rw-r--r-- | tests/ui/type-alias-impl-trait/broken_mir.rs | 16 |
2 files changed, 25 insertions, 6 deletions
diff --git a/compiler/rustc_const_eval/src/util/compare_types.rs b/compiler/rustc_const_eval/src/util/compare_types.rs index 88d4f5e715c..83376c8e992 100644 --- a/compiler/rustc_const_eval/src/util/compare_types.rs +++ b/compiler/rustc_const_eval/src/util/compare_types.rs @@ -57,12 +57,15 @@ pub fn is_subtype<'tcx>( // we would get unification errors because we're unable to look into opaque types, // even if they're constrained in our current function. for (key, ty) in infcx.take_opaque_types() { - span_bug!( - ty.hidden_type.span, - "{}, {}", - tcx.type_of(key.def_id).instantiate(tcx, key.args), - ty.hidden_type.ty - ); + let hidden_ty = tcx.type_of(key.def_id).instantiate(tcx, key.args); + if hidden_ty != ty.hidden_type.ty { + span_bug!( + ty.hidden_type.span, + "{}, {}", + tcx.type_of(key.def_id).instantiate(tcx, key.args), + ty.hidden_type.ty + ); + } } errors.is_empty() } diff --git a/tests/ui/type-alias-impl-trait/broken_mir.rs b/tests/ui/type-alias-impl-trait/broken_mir.rs new file mode 100644 index 00000000000..b68e798fb7c --- /dev/null +++ b/tests/ui/type-alias-impl-trait/broken_mir.rs @@ -0,0 +1,16 @@ +//! ICE: https://github.com/rust-lang/rust/issues/114121 +//! This test checks that MIR validation never constrains +//! new hidden types that *differ* from the actual hidden types. +//! This test used to ICE because oli-obk assumed mir validation +//! was only ever run after opaque types were revealed in MIR. + +// compile-flags: -Zvalidate-mir +// check-pass + +fn main() { + let _ = Some(()).into_iter().flat_map(|_| Some(()).into_iter().flat_map(func)); +} + +fn func(_: ()) -> impl Iterator<Item = ()> { + Some(()).into_iter().flat_map(|_| vec![]) +} |