diff options
4 files changed, 20 insertions, 1 deletions
diff --git a/compiler/rustc_const_eval/src/const_eval/valtrees.rs b/compiler/rustc_const_eval/src/const_eval/valtrees.rs index 4d54c01830b..b10f2e9f862 100644 --- a/compiler/rustc_const_eval/src/const_eval/valtrees.rs +++ b/compiler/rustc_const_eval/src/const_eval/valtrees.rs @@ -337,7 +337,7 @@ fn valtree_into_mplace<'tcx>( match ty.kind() { ty::FnDef(_, _) => { - ecx.write_immediate(Immediate::Uninit, &place.into()).unwrap(); + // Zero-sized type, nothing to do. } ty::Bool | ty::Int(_) | ty::Uint(_) | ty::Float(_) | ty::Char => { let scalar_int = valtree.unwrap_leaf(); diff --git a/compiler/rustc_const_eval/src/interpret/operand.rs b/compiler/rustc_const_eval/src/interpret/operand.rs index 5310ef0bb3e..a7f66071fe2 100644 --- a/compiler/rustc_const_eval/src/interpret/operand.rs +++ b/compiler/rustc_const_eval/src/interpret/operand.rs @@ -245,6 +245,12 @@ impl<'tcx, Prov: Provenance> ImmTy<'tcx, Prov> { impl<'tcx, Prov: Provenance> OpTy<'tcx, Prov> { pub fn len(&self, cx: &impl HasDataLayout) -> InterpResult<'tcx, u64> { if self.layout.is_unsized() { + if matches!(self.op, Operand::Immediate(Immediate::Uninit)) { + // Uninit unsized places shouldn't occur. In the interpreter we have them + // temporarily for unsized arguments before their value is put in; in ConstProp they + // remain uninit and this code can actually be reached. + throw_inval!(UninitUnsizedLocal); + } // There are no unsized immediates. self.assert_mem_place().len(cx) } else { diff --git a/compiler/rustc_middle/src/mir/interpret/error.rs b/compiler/rustc_middle/src/mir/interpret/error.rs index c5137cf0666..e45284ca506 100644 --- a/compiler/rustc_middle/src/mir/interpret/error.rs +++ b/compiler/rustc_middle/src/mir/interpret/error.rs @@ -134,6 +134,9 @@ pub enum InvalidProgramInfo<'tcx> { FnAbiAdjustForForeignAbi(call::AdjustForForeignAbiError), /// SizeOf of unsized type was requested. SizeOfUnsizedType(Ty<'tcx>), + /// An unsized local was accessed without having been initialized. + /// This is not meaningful as we can't even have backing memory for such locals. + UninitUnsizedLocal, } impl fmt::Display for InvalidProgramInfo<'_> { @@ -150,6 +153,7 @@ impl fmt::Display for InvalidProgramInfo<'_> { Layout(ref err) => write!(f, "{err}"), FnAbiAdjustForForeignAbi(ref err) => write!(f, "{err}"), SizeOfUnsizedType(ty) => write!(f, "size_of called on unsized type `{ty}`"), + UninitUnsizedLocal => write!(f, "unsized local is used while uninitialized"), } } } diff --git a/tests/ui/const_prop/unsized-local-ice.rs b/tests/ui/const_prop/unsized-local-ice.rs new file mode 100644 index 00000000000..c725b3238ea --- /dev/null +++ b/tests/ui/const_prop/unsized-local-ice.rs @@ -0,0 +1,9 @@ +// build-pass +//! Regression test for <https://github.com/rust-lang/rust/issues/68538>. +#![feature(unsized_fn_params)] + +pub fn take_unsized_slice(s: [u8]) { + s[0]; +} + +fn main() {} |