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interpret: make write functions generic over the place type

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This commit is contained in:
Ralf Jung
2023-07-25 22:04:02 +02:00
parent 4fc6b33474
commit 00fb45dccd
26 changed files with 243 additions and 213 deletions
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17
compiler/rustc_const_eval/src/interpret/discriminant.rs
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@@ -5,7 +5,8 @@ use rustc_middle::{mir, ty};
use rustc_target::abi::{self, TagEncoding};
use rustc_target::abi::{VariantIdx, Variants};
use super::{ImmTy, InterpCx, InterpResult, Machine, OpTy, PlaceTy, Scalar};
use super::place::Writeable;
use super::{ImmTy, InterpCx, InterpResult, Machine, OpTy, Scalar};
impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
/// Writes the discriminant of the given variant.
@@ -13,7 +14,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
pub fn write_discriminant(
&mut self,
variant_index: VariantIdx,
dest: &PlaceTy<'tcx, M::Provenance>,
dest: &impl Writeable<'tcx, M::Provenance>,
) -> InterpResult<'tcx> {
// Layout computation excludes uninhabited variants from consideration
// therefore there's no way to represent those variants in the given layout.
@@ -21,11 +22,11 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
// discriminant, so we cannot do anything here.
// When evaluating we will always error before even getting here, but ConstProp 'executes'
// dead code, so we cannot ICE here.
if dest.layout.for_variant(self, variant_index).abi.is_uninhabited() {
if dest.layout().for_variant(self, variant_index).abi.is_uninhabited() {
throw_ub!(UninhabitedEnumVariantWritten(variant_index))
}
match dest.layout.variants {
match dest.layout().variants {
abi::Variants::Single { index } => {
assert_eq!(index, variant_index);
}
@@ -38,8 +39,12 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
// No need to validate that the discriminant here because the
// `TyAndLayout::for_variant()` call earlier already checks the variant is valid.
let discr_val =
dest.layout.ty.discriminant_for_variant(*self.tcx, variant_index).unwrap().val;
let discr_val = dest
.layout()
.ty
.discriminant_for_variant(*self.tcx, variant_index)
.unwrap()
.val;
// raw discriminants for enums are isize or bigger during
// their computation, but the in-memory tag is the smallest possible