bjoernager/rust
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inhibit layout randomization for Box

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The 8472 2024-08-31 14:43:23 +02:00
parent 1e377c5b9f
commit df20808f4d
3 changed files with 27 additions and 9 deletions
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11
compiler/rustc_abi/src/layout.rs
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@ -968,8 +968,8 @@ fn univariant<
let mut align = if pack.is_some() { dl.i8_align } else { dl.aggregate_align };
let mut max_repr_align = repr.align;
let mut inverse_memory_index: IndexVec<u32, FieldIdx> = fields.indices().collect();
let optimize = !repr.inhibit_struct_field_reordering();
if optimize && fields.len() > 1 {
let optimize_field_order = !repr.inhibit_struct_field_reordering();
if optimize_field_order && fields.len() > 1 {
let end = if let StructKind::MaybeUnsized = kind { fields.len() - 1 } else { fields.len() };
let optimizing = &mut inverse_memory_index.raw[..end];
let fields_excluding_tail = &fields.raw[..end];
@ -1176,7 +1176,7 @@ fn univariant<
// If field 5 has offset 0, offsets[0] is 5, and memory_index[5] should be 0.
// Field 5 would be the first element, so memory_index is i:
// Note: if we didn't optimize, it's already right.
let memory_index = if optimize {
let memory_index = if optimize_field_order {
inverse_memory_index.invert_bijective_mapping()
} else {
debug_assert!(inverse_memory_index.iter().copied().eq(fields.indices()));
@ -1189,6 +1189,9 @@ fn univariant<
}
let mut layout_of_single_non_zst_field = None;
let mut abi = Abi::Aggregate { sized };
let optimize_abi = !repr.inhibit_newtype_abi_optimization();
// Try to make this a Scalar/ScalarPair.
if sized && size.bytes() > 0 {
// We skip *all* ZST here and later check if we are good in terms of alignment.
@ -1205,7 +1208,7 @@ fn univariant<
match field.abi {
// For plain scalars, or vectors of them, we can't unpack
// newtypes for `#[repr(C)]`, as that affects C ABIs.
Abi::Scalar(_) | Abi::Vector { .. } if optimize => {
Abi::Scalar(_) | Abi::Vector { .. } if optimize_abi => {
abi = field.abi;
}
// But scalar pairs are Rust-specific and get