diff options
| -rw-r--r-- | src/librustc_mir/const_eval.rs | 26 | ||||
| -rw-r--r-- | src/test/ui/consts/union_constant.rs | 11 |
2 files changed, 24 insertions, 13 deletions
diff --git a/src/librustc_mir/const_eval.rs b/src/librustc_mir/const_eval.rs index 43f019019f7..71d9398c686 100644 --- a/src/librustc_mir/const_eval.rs +++ b/src/librustc_mir/const_eval.rs @@ -65,12 +65,12 @@ pub(crate) fn eval_promoted<'a, 'mir, 'tcx>( fn mplace_to_const<'tcx>( ecx: &CompileTimeEvalContext<'_, '_, 'tcx>, mplace: MPlaceTy<'tcx>, -) -> EvalResult<'tcx, ty::Const<'tcx>> { +) -> ty::Const<'tcx> { let MemPlace { ptr, align, meta } = *mplace; // extract alloc-offset pair assert!(meta.is_none()); - let ptr = ptr.to_ptr()?; - let alloc = ecx.memory.get(ptr.alloc_id)?; + let ptr = ptr.to_ptr().unwrap(); + let alloc = ecx.memory.get(ptr.alloc_id).unwrap(); assert!(alloc.align >= align); assert!(alloc.bytes.len() as u64 - ptr.offset.bytes() >= mplace.layout.size.bytes()); let mut alloc = alloc.clone(); @@ -79,16 +79,16 @@ fn mplace_to_const<'tcx>( // interned this? I thought that is the entire point of that `FinishStatic` stuff? let alloc = ecx.tcx.intern_const_alloc(alloc); let val = ConstValue::ByRef(ptr, alloc); - Ok(ty::Const { val, ty: mplace.layout.ty }) + ty::Const { val, ty: mplace.layout.ty } } fn op_to_const<'tcx>( ecx: &CompileTimeEvalContext<'_, '_, 'tcx>, op: OpTy<'tcx>, -) -> EvalResult<'tcx, ty::Const<'tcx>> { - // We do not normalize just any data. Only scalar layout and slices. +) -> ty::Const<'tcx> { + // We do not normalize just any data. Only non-union scalars and slices. let normalize = match op.layout.abi { - layout::Abi::Scalar(..) => true, + layout::Abi::Scalar(..) => op.layout.ty.ty_adt_def().map_or(true, |adt| !adt.is_union()), layout::Abi::ScalarPair(..) => op.layout.ty.is_slice(), _ => false, }; @@ -100,11 +100,11 @@ fn op_to_const<'tcx>( let val = match normalized_op { Ok(mplace) => return mplace_to_const(ecx, mplace), Err(Immediate::Scalar(x)) => - ConstValue::Scalar(x.not_undef()?), + ConstValue::Scalar(x.not_undef().unwrap()), Err(Immediate::ScalarPair(a, b)) => - ConstValue::Slice(a.not_undef()?, b.to_usize(ecx)?), + ConstValue::Slice(a.not_undef().unwrap(), b.to_usize(ecx).unwrap()), }; - Ok(ty::Const { val, ty: op.layout.ty }) + ty::Const { val, ty: op.layout.ty } } fn eval_body_and_ecx<'a, 'mir, 'tcx>( @@ -488,7 +488,7 @@ pub fn const_field<'a, 'tcx>( let field = ecx.operand_field(down, field.index() as u64).unwrap(); // and finally move back to the const world, always normalizing because // this is not called for statics. - op_to_const(&ecx, field).unwrap() + op_to_const(&ecx, field) } // this function uses `unwrap` copiously, because an already validated constant must have valid @@ -534,9 +534,9 @@ fn validate_and_turn_into_const<'a, 'tcx>( // Now that we validated, turn this into a proper constant. let def_id = cid.instance.def.def_id(); if tcx.is_static(def_id).is_some() || cid.promoted.is_some() { - mplace_to_const(&ecx, mplace) + Ok(mplace_to_const(&ecx, mplace)) } else { - op_to_const(&ecx, mplace.into()) + Ok(op_to_const(&ecx, mplace.into())) } })(); diff --git a/src/test/ui/consts/union_constant.rs b/src/test/ui/consts/union_constant.rs new file mode 100644 index 00000000000..074014908ba --- /dev/null +++ b/src/test/ui/consts/union_constant.rs @@ -0,0 +1,11 @@ +// compile-pass + +union Uninit { + _never_use: *const u8, + uninit: (), +} + +const UNINIT: Uninit = Uninit { uninit: () }; + +fn main() {} + |