bjoernager/rust
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Remove most manual LayoutData creations and move them to rustc_abi

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...either as:
- methods on LayoutCalculator, for faillible operations;
- constructors on LayoutData, for infaillible ones.
This commit is contained in:
Moulins 2025-02-28 04:57:17 +01:00
parent cdd8af2299
commit 9917173575
6 changed files with 228 additions and 267 deletions
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42
compiler/rustc_abi/src/lib.rs
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@ -1744,48 +1744,6 @@ impl<FieldIdx: Idx, VariantIdx: Idx> LayoutData<FieldIdx, VariantIdx> {
pub fn is_uninhabited(&self) -> bool {
self.uninhabited
}
pub fn scalar<C: HasDataLayout>(cx: &C, scalar: Scalar) -> Self {
let largest_niche = Niche::from_scalar(cx, Size::ZERO, scalar);
let size = scalar.size(cx);
let align = scalar.align(cx);
let range = scalar.valid_range(cx);
// All primitive types for which we don't have subtype coercions should get a distinct seed,
// so that types wrapping them can use randomization to arrive at distinct layouts.
//
// Some type information is already lost at this point, so as an approximation we derive
// the seed from what remains. For example on 64-bit targets usize and u64 can no longer
// be distinguished.
let randomization_seed = size
.bytes()
.wrapping_add(
match scalar.primitive() {
Primitive::Int(_, true) => 1,
Primitive::Int(_, false) => 2,
Primitive::Float(_) => 3,
Primitive::Pointer(_) => 4,
} << 32,
)
// distinguishes references from pointers
.wrapping_add((range.start as u64).rotate_right(16))
// distinguishes char from u32 and bool from u8
.wrapping_add((range.end as u64).rotate_right(16));
LayoutData {
variants: Variants::Single { index: VariantIdx::new(0) },
fields: FieldsShape::Primitive,
backend_repr: BackendRepr::Scalar(scalar),
largest_niche,
uninhabited: false,
size,
align,
max_repr_align: None,
unadjusted_abi_align: align.abi,
randomization_seed: Hash64::new(randomization_seed),
}
}
}
impl<FieldIdx: Idx, VariantIdx: Idx> fmt::Debug for LayoutData<FieldIdx, VariantIdx>