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interpret: ImmTy: tighten sanity checks in offset logic

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This commit is contained in:
Ralf Jung 2024-08-24 14:11:28 +02:00
parent edbc000fa4
commit 493cf6a7e9
1 changed files with 15 additions and 6 deletions
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21
compiler/rustc_const_eval/src/interpret/operand.rs
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@ -319,6 +319,7 @@ fn offset_(&self, offset: Size, layout: TyAndLayout<'tcx>, cx: &impl HasDataLayo
// some fieldless enum variants can have non-zero size but still `Aggregate` ABI... try // some fieldless enum variants can have non-zero size but still `Aggregate` ABI... try
// to detect those here and also give them no data // to detect those here and also give them no data
_ if matches!(layout.abi, Abi::Aggregate { .. }) _ if matches!(layout.abi, Abi::Aggregate { .. })
&& matches!(layout.variants, abi::Variants::Single { .. })
&& matches!(&layout.fields, abi::FieldsShape::Arbitrary { offsets, .. } if offsets.len() == 0) => && matches!(&layout.fields, abi::FieldsShape::Arbitrary { offsets, .. } if offsets.len() == 0) =>
{ {
Immediate::Uninit Immediate::Uninit
@ -328,8 +329,9 @@ fn offset_(&self, offset: Size, layout: TyAndLayout<'tcx>, cx: &impl HasDataLayo
assert_eq!(offset.bytes(), 0); assert_eq!(offset.bytes(), 0);
assert!( assert!(
match (self.layout.abi, layout.abi) { match (self.layout.abi, layout.abi) {
(Abi::Scalar(..), Abi::Scalar(..)) => true, (Abi::Scalar(l), Abi::Scalar(r)) => l.size(cx) == r.size(cx),
(Abi::ScalarPair(..), Abi::ScalarPair(..)) => true, (Abi::ScalarPair(l1, l2), Abi::ScalarPair(r1, r2)) =>
l1.size(cx) == r1.size(cx) && l2.size(cx) == r2.size(cx),
_ => false, _ => false,
}, },
"cannot project into {} immediate with equally-sized field {}\nouter ABI: {:#?}\nfield ABI: {:#?}", "cannot project into {} immediate with equally-sized field {}\nouter ABI: {:#?}\nfield ABI: {:#?}",
@ -344,16 +346,23 @@ fn offset_(&self, offset: Size, layout: TyAndLayout<'tcx>, cx: &impl HasDataLayo
(Immediate::ScalarPair(a_val, b_val), Abi::ScalarPair(a, b)) => { (Immediate::ScalarPair(a_val, b_val), Abi::ScalarPair(a, b)) => {
assert_matches!(layout.abi, Abi::Scalar(..)); assert_matches!(layout.abi, Abi::Scalar(..));
Immediate::from(if offset.bytes() == 0 { Immediate::from(if offset.bytes() == 0 {
debug_assert_eq!(layout.size, a.size(cx)); // It is "okay" to transmute from `usize` to a pointer (GVN relies on that).
// So only compare the size.
assert_eq!(layout.size, a.size(cx));
a_val a_val
} else { } else {
debug_assert_eq!(offset, a.size(cx).align_to(b.align(cx).abi)); assert_eq!(offset, a.size(cx).align_to(b.align(cx).abi));
debug_assert_eq!(layout.size, b.size(cx)); assert_eq!(layout.size, b.size(cx));
b_val b_val
}) })
} }
// everything else is a bug // everything else is a bug
_ => bug!("invalid field access on immediate {}, layout {:#?}", self, self.layout), _ => bug!(
"invalid field access on immediate {} at offset {}, original layout {:#?}",
self,
offset.bytes(),
self.layout
),
}; };
ImmTy::from_immediate(inner_val, layout) ImmTy::from_immediate(inner_val, layout)