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emilioemilio
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ty: Use underlying layout of typedefs if available.
This fixes struct layout issues with over-aligned typedefs, which rust can't represent, see #3449 for context and some other discussion. This is kinda ugly tho, but as far as I can tell there's no good way of getting the right ABI and struct layout at the same time...
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‎bindgen-tests/tests/expectations/tests/issue-3406.rs‎

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‎bindgen-tests/tests/headers/issue-3406.h‎

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@@ -2,7 +2,26 @@ struct __attribute__((aligned(16))) Inner {
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char byte;
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};
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typedef int AlignedInt __attribute__((aligned(16)));
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typedef AlignedInt NestedAlignedInt;
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struct Outer {
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int before;
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struct Inner inner;
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};
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struct Outer2 {
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int before;
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AlignedInt one;
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AlignedInt two;
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};
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struct Outer3 {
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int before;
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AlignedInt inner;
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};
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struct Outer4 {
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int before;
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NestedAlignedInt inner;
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};

‎bindgen/ir/ty.rs‎

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@@ -218,6 +218,15 @@ impl Type {
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/// What is the layout of this type?
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pub(crate) fn layout(&self, ctx: &BindgenContext) -> Option<Layout> {
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if let TypeKind::Alias(inner) | TypeKind::ResolvedTypeRef(inner) =
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self.kind
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{
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// HACK(emilio): Rust can't represent over-aligned typedefs, so prefer the inner type's
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// layout if available, to get struct layout correct at least...
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if let Some(l) = ctx.resolve_type(inner).layout(ctx) {
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return Some(l);
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}
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}
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self.layout.or_else(|| {
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match self.kind {
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TypeKind::Comp(ref ci) => ci.layout(ctx),

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