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interpret: fix projecting into an unsized field of a local

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new invariant: Place::Local never refers to something unsized
This commit is contained in:
Ralf Jung
2023-08-04 21:42:35 +02:00
parent 61efe9d298
commit bdd5855b8e
6 changed files with 124 additions and 97 deletions
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56
compiler/rustc_const_eval/src/interpret/operand.rs
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@@ -291,23 +291,21 @@ impl<'tcx, Prov: Provenance> Projectable<'tcx, Prov> for ImmTy<'tcx, Prov> {
self.layout
}
fn meta<'mir, M: Machine<'mir, 'tcx, Provenance = Prov>>(
&self,
_ecx: &InterpCx<'mir, 'tcx, M>,
) -> InterpResult<'tcx, MemPlaceMeta<M::Provenance>> {
assert!(self.layout.is_sized()); // unsized ImmTy can only exist temporarily and should never reach this here
#[inline(always)]
fn meta(&self) -> InterpResult<'tcx, MemPlaceMeta<Prov>> {
debug_assert!(self.layout.is_sized()); // unsized ImmTy can only exist temporarily and should never reach this here
Ok(MemPlaceMeta::None)
}
fn offset_with_meta(
fn offset_with_meta<'mir, M: Machine<'mir, 'tcx, Provenance = Prov>>(
&self,
offset: Size,
meta: MemPlaceMeta<Prov>,
layout: TyAndLayout<'tcx>,
cx: &impl HasDataLayout,
ecx: &InterpCx<'mir, 'tcx, M>,
) -> InterpResult<'tcx, Self> {
assert_matches!(meta, MemPlaceMeta::None); // we can't store this anywhere anyway
Ok(self.offset_(offset, layout, cx))
Ok(self.offset_(offset, layout, ecx))
}
fn to_op<'mir, M: Machine<'mir, 'tcx, Provenance = Prov>>(
@@ -318,49 +316,39 @@ impl<'tcx, Prov: Provenance> Projectable<'tcx, Prov> for ImmTy<'tcx, Prov> {
}
}
impl<'tcx, Prov: Provenance> OpTy<'tcx, Prov> {
// Provided as inherent method since it doesn't need the `ecx` of `Projectable::meta`.
pub fn meta(&self) -> InterpResult<'tcx, MemPlaceMeta<Prov>> {
Ok(if self.layout.is_unsized() {
if matches!(self.op, Operand::Immediate(_)) {
// Unsized immediate OpTy cannot occur. We create a MemPlace for all unsized locals during argument passing.
// However, ConstProp doesn't do that, so we can run into this nonsense situation.
throw_inval!(ConstPropNonsense);
}
// There are no unsized immediates.
self.assert_mem_place().meta
} else {
MemPlaceMeta::None
})
}
}
impl<'tcx, Prov: Provenance + 'static> Projectable<'tcx, Prov> for OpTy<'tcx, Prov> {
#[inline(always)]
fn layout(&self) -> TyAndLayout<'tcx> {
self.layout
}
fn meta<'mir, M: Machine<'mir, 'tcx, Provenance = Prov>>(
&self,
_ecx: &InterpCx<'mir, 'tcx, M>,
) -> InterpResult<'tcx, MemPlaceMeta<M::Provenance>> {
self.meta()
fn meta(&self) -> InterpResult<'tcx, MemPlaceMeta<Prov>> {
Ok(match self.as_mplace_or_imm() {
Left(mplace) => mplace.meta,
Right(_) => {
if self.layout.is_unsized() {
// Unsized immediate OpTy cannot occur. We create a MemPlace for all unsized locals during argument passing.
// However, ConstProp doesn't do that, so we can run into this nonsense situation.
throw_inval!(ConstPropNonsense);
}
MemPlaceMeta::None
}
})
}
fn offset_with_meta(
fn offset_with_meta<'mir, M: Machine<'mir, 'tcx, Provenance = Prov>>(
&self,
offset: Size,
meta: MemPlaceMeta<Prov>,
layout: TyAndLayout<'tcx>,
cx: &impl HasDataLayout,
ecx: &InterpCx<'mir, 'tcx, M>,
) -> InterpResult<'tcx, Self> {
match self.as_mplace_or_imm() {
Left(mplace) => Ok(mplace.offset_with_meta(offset, meta, layout, cx)?.into()),
Left(mplace) => Ok(mplace.offset_with_meta(offset, meta, layout, ecx)?.into()),
Right(imm) => {
assert!(!meta.has_meta()); // no place to store metadata here
// Every part of an uninit is uninit.
Ok(imm.offset(offset, layout, cx)?.into())
Ok(imm.offset(offset, layout, ecx)?.into())
}
}
}