diff options
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/traits/consts.rs | 6 | ||||
| -rw-r--r-- | compiler/rustc_const_eval/src/interpret/operand.rs | 2 |
2 files changed, 7 insertions, 1 deletions
diff --git a/compiler/rustc_codegen_ssa/src/traits/consts.rs b/compiler/rustc_codegen_ssa/src/traits/consts.rs index d6e9bfce1a4..822c19155e3 100644 --- a/compiler/rustc_codegen_ssa/src/traits/consts.rs +++ b/compiler/rustc_codegen_ssa/src/traits/consts.rs @@ -5,7 +5,13 @@ use rustc_target::abi; pub trait ConstMethods<'tcx>: BackendTypes { // Constant constructors fn const_null(&self, t: Self::Type) -> Self::Value; + /// Generate an uninitialized value (matching uninitialized memory in MIR). + /// Whether memory is initialized or not is tracked byte-for-byte. fn const_undef(&self, t: Self::Type) -> Self::Value; + /// Generate a fake value. Poison always affects the entire value, even if just a single byte is + /// poison. This can only be used in codepaths that are already UB, i.e., UB-free Rust code + /// (including code that e.g. copies uninit memory with `MaybeUninit`) can never encounter a + /// poison value. fn const_poison(&self, t: Self::Type) -> Self::Value; fn const_int(&self, t: Self::Type, i: i64) -> Self::Value; fn const_uint(&self, t: Self::Type, i: u64) -> Self::Value; diff --git a/compiler/rustc_const_eval/src/interpret/operand.rs b/compiler/rustc_const_eval/src/interpret/operand.rs index da45fdca1a1..47383c0eabc 100644 --- a/compiler/rustc_const_eval/src/interpret/operand.rs +++ b/compiler/rustc_const_eval/src/interpret/operand.rs @@ -31,7 +31,7 @@ pub enum Immediate<Prov: Provenance = AllocId> { /// A pair of two scalar value (must have `ScalarPair` ABI where both fields are /// `Scalar::Initialized`). ScalarPair(Scalar<Prov>, Scalar<Prov>), - /// A value of fully uninitialized memory. Can have and size and layout. + /// A value of fully uninitialized memory. Can have arbitrary size and layout. Uninit, } |