bjoernager/rust
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i686-windows: make requested alignment > 4 special case apply transitively

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This commit is contained in:
Erik Desjardins 2023-07-14 17:48:13 -04:00
parent f297f3200f
commit 2daacf5af9
12 changed files with 113 additions and 115 deletions
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40
compiler/rustc_abi/src/layout.rs
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@ -40,7 +40,7 @@ pub trait LayoutCalculator {
largest_niche,
align,
size,
repr_align: None,
max_repr_align: None,
unadjusted_abi_align: align.abi,
}
}
@ -124,7 +124,7 @@ pub trait LayoutCalculator {
largest_niche: None,
align: dl.i8_align,
size: Size::ZERO,
repr_align: None,
max_repr_align: None,
unadjusted_abi_align: dl.i8_align.abi,
}
}
@ -293,6 +293,7 @@ pub trait LayoutCalculator {
}
let mut align = dl.aggregate_align;
let mut max_repr_align = repr.align;
let mut unadjusted_abi_align = align.abi;
let mut variant_layouts = variants
@ -302,6 +303,7 @@ pub trait LayoutCalculator {
st.variants = Variants::Single { index: j };
align = align.max(st.align);
max_repr_align = max_repr_align.max(st.max_repr_align);
unadjusted_abi_align = unadjusted_abi_align.max(st.unadjusted_abi_align);
Some(st)
@ -429,7 +431,7 @@ pub trait LayoutCalculator {
largest_niche,
size,
align,
repr_align: repr.align,
max_repr_align,
unadjusted_abi_align,
};
@ -465,6 +467,7 @@ pub trait LayoutCalculator {
let (min_ity, signed) = discr_range_of_repr(min, max); //Integer::repr_discr(tcx, ty, &repr, min, max);
let mut align = dl.aggregate_align;
let mut max_repr_align = repr.align;
let mut unadjusted_abi_align = align.abi;
let mut size = Size::ZERO;
@ -509,6 +512,7 @@ pub trait LayoutCalculator {
}
size = cmp::max(size, st.size);
align = align.max(st.align);
max_repr_align = max_repr_align.max(st.max_repr_align);
unadjusted_abi_align = unadjusted_abi_align.max(st.unadjusted_abi_align);
Some(st)
})
@ -703,7 +707,7 @@ pub trait LayoutCalculator {
abi,
align,
size,
repr_align: repr.align,
max_repr_align,
unadjusted_abi_align,
};
@ -744,6 +748,7 @@ pub trait LayoutCalculator {
let dl = self.current_data_layout();
let dl = dl.borrow();
let mut align = if repr.pack.is_some() { dl.i8_align } else { dl.aggregate_align };
let mut max_repr_align = repr.align;
// If all the non-ZST fields have the same ABI and union ABI optimizations aren't
// disabled, we can use that common ABI for the union as a whole.
@ -761,6 +766,7 @@ pub trait LayoutCalculator {
assert!(field.0.is_sized());
align = align.max(field.align());
max_repr_align = max_repr_align.max(field.max_repr_align());
size = cmp::max(size, field.size());
if field.0.is_zst() {
@ -827,7 +833,7 @@ pub trait LayoutCalculator {
largest_niche: None,
align,
size: size.align_to(align.abi),
repr_align: repr.align,
max_repr_align,
unadjusted_abi_align,
})
}
@ -849,6 +855,7 @@ fn univariant(
) -> Option<LayoutS> {
let pack = repr.pack;
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_opt();
if optimize && fields.len() > 1 {
@ -1017,6 +1024,7 @@ fn univariant(
};
offset = offset.align_to(field_align.abi);
align = align.max(field_align);
max_repr_align = max_repr_align.max(field.max_repr_align());
debug!("univariant offset: {:?} field: {:#?}", offset, field);
offsets[i] = offset;
@ -1133,28 +1141,16 @@ fn univariant(
abi = Abi::Uninhabited;
}
let (repr_align, unadjusted_abi_align) = if repr.transparent() {
let unadjusted_abi_align = if repr.transparent() {
match layout_of_single_non_zst_field {
Some(l) => (l.repr_align(), l.unadjusted_abi_align()),
Some(l) => l.unadjusted_abi_align(),
None => {
// `repr(transparent)` with all ZST fields.
//
// Using `None` for `repr_align` here is technically incorrect, since one of
// the ZSTs could have `repr(align(1))`. It's an interesting question, if you have
// `#{repr(transparent)] struct Foo((), ZstWithReprAlign1)`, which of those ZSTs'
// ABIs is forwarded by `repr(transparent)`? The answer to that question determines
// whether we should use `None` or `Some(align 1)` here. Thanksfully, two things
// together mean this doesn't matter:
// - You're not allowed to have a `repr(transparent)` struct that contains
// `repr(align)` > 1 ZSTs. See error E0691.
// - MSVC never treats requested align 1 differently from natural align 1.
// (And the `repr_align` field is only used on i686-windows, see `LayoutS` docs.)
// So just use `None` for now.
(None, align.abi)
align.abi
}
}
} else {
(repr.align, unadjusted_abi_align)
unadjusted_abi_align
};
Some(LayoutS {
@ -1164,7 +1160,7 @@ fn univariant(
largest_niche,
align,
size,
repr_align,
max_repr_align,
unadjusted_abi_align,
})
}