diff options
Diffstat (limited to 'compiler/rustc_const_eval/src/interpret/projection.rs')
| -rw-r--r-- | compiler/rustc_const_eval/src/interpret/projection.rs | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/compiler/rustc_const_eval/src/interpret/projection.rs b/compiler/rustc_const_eval/src/interpret/projection.rs index 742339f2b..77da8f104 100644 --- a/compiler/rustc_const_eval/src/interpret/projection.rs +++ b/compiler/rustc_const_eval/src/interpret/projection.rs @@ -1,14 +1,12 @@ //! This file implements "place projections"; basically a symmetric API for 3 types: MPlaceTy, OpTy, PlaceTy. //! -//! OpTy and PlaceTy genrally work by "let's see if we are actually an MPlaceTy, and do something custom if not". +//! OpTy and PlaceTy generally work by "let's see if we are actually an MPlaceTy, and do something custom if not". //! For PlaceTy, the custom thing is basically always to call `force_allocation` and then use the MPlaceTy logic anyway. //! For OpTy, the custom thing on field pojections has to be pretty clever (since `Operand::Immediate` can have fields), //! but for array/slice operations it only has to worry about `Operand::Uninit`. That makes the value part trivial, //! but we still need to do bounds checking and adjust the layout. To not duplicate that with MPlaceTy, we actually //! implement the logic on OpTy, and MPlaceTy calls that. -use std::hash::Hash; - use rustc_middle::mir; use rustc_middle::ty; use rustc_middle::ty::layout::LayoutOf; @@ -22,7 +20,7 @@ use super::{ // FIXME: Working around https://github.com/rust-lang/rust/issues/54385 impl<'mir, 'tcx: 'mir, Prov, M> InterpCx<'mir, 'tcx, M> where - Prov: Provenance + Eq + Hash + 'static, + Prov: Provenance + 'static, M: Machine<'mir, 'tcx, Provenance = Prov>, { //# Field access @@ -100,6 +98,8 @@ where // This makes several assumptions about what layouts we will encounter; we match what // codegen does as good as we can (see `extract_field` in `rustc_codegen_ssa/src/mir/operand.rs`). let field_val: Immediate<_> = match (*base, base.layout.abi) { + // if the entire value is uninit, then so is the field (can happen in ConstProp) + (Immediate::Uninit, _) => Immediate::Uninit, // the field contains no information, can be left uninit _ if field_layout.is_zst() => Immediate::Uninit, // the field covers the entire type @@ -124,6 +124,7 @@ where b_val }) } + // everything else is a bug _ => span_bug!( self.cur_span(), "invalid field access on immediate {}, layout {:#?}", |