diff options
| -rw-r--r-- | src/librustc_mir/interpret/place.rs | 22 |
1 files changed, 17 insertions, 5 deletions
diff --git a/src/librustc_mir/interpret/place.rs b/src/librustc_mir/interpret/place.rs index ece54daf4c6..b16c7ffbffd 100644 --- a/src/librustc_mir/interpret/place.rs +++ b/src/librustc_mir/interpret/place.rs @@ -283,6 +283,18 @@ impl<'tcx, Tag: ::std::fmt::Debug> PlaceTy<'tcx, Tag> { } } +/// Test if it is valid for a MIR assignment to assign `src`-typed place to `dest`-typed value. +fn mir_assign_valid_types<'tcx>(src: Ty<'tcx>, dest: Ty<'tcx>) -> bool { + src == dest + || match (&src.kind, &dest.kind) { + // After MIR optimizations, there can be assignments that change reference mutability. + (ty::Ref(_, src_pointee, _), ty::Ref(_, dest_pointee, _)) => { + src_pointee == dest_pointee + } + _ => false, + } +} + // separating the pointer tag for `impl Trait`, see https://github.com/rust-lang/rust/issues/54385 impl<'mir, 'tcx, Tag, M> InterpCx<'mir, 'tcx, M> where @@ -869,10 +881,10 @@ where // We do NOT compare the types for equality, because well-typed code can // actually "transmute" `&mut T` to `&T` in an assignment without a cast. assert!( - src.layout.layout == dest.layout.layout, - "Layout mismatch when copying!\nsrc: {:#?}\ndest: {:#?}", - src, - dest + mir_assign_valid_types(src.layout.ty, dest.layout.ty), + "type mismatch when copying!\nsrc: {:?}, dest: {:?}", + src.layout.ty, + dest.layout.ty, ); // Let us see if the layout is simple so we take a shortcut, avoid force_allocation. @@ -923,7 +935,7 @@ where src: OpTy<'tcx, M::PointerTag>, dest: PlaceTy<'tcx, M::PointerTag>, ) -> InterpResult<'tcx> { - if src.layout.layout == dest.layout.layout { + if mir_assign_valid_types(src.layout.ty, dest.layout.ty) { // Fast path: Just use normal `copy_op` return self.copy_op(src, dest); } |