Input header:
class A {
class I;
};
class A::I {
int i;
};Generated correct Rust binding prior to llvm/llvm-project#147835:
#[repr(C)]
#[derive(Debug, Copy, Clone)]
pub struct A {
pub _address: u8,
}
#[allow(clippy::unnecessary_operation, clippy::identity_op)]
const _: () = {
["Size of A"][::std::mem::size_of::<A>() - 1usize];
["Alignment of A"][::std::mem::align_of::<A>() - 1usize];
};
#[repr(C)]
#[derive(Debug, Copy, Clone)]
pub struct A_I {
pub i: ::std::os::raw::c_int,
}
#[allow(clippy::unnecessary_operation, clippy::identity_op)]
const _: () = {
["Size of A_I"][::std::mem::size_of::<A_I>() - 4usize];
["Alignment of A_I"][::std::mem::align_of::<A_I>() - 4usize];
["Offset of field: A_I::i"][::std::mem::offset_of!(A_I, i) - 0usize];
};Generated incorrect Rust binding after that LLVM refactor, which is part of LLVM 22:
#[repr(C)]
#[derive(Debug, Copy, Clone)]
pub struct A {
pub _address: u8,
}
#[allow(clippy::unnecessary_operation, clippy::identity_op)]
const _: () = {
["Size of A"][::std::mem::size_of::<A>() - 1usize];
["Alignment of A"][::std::mem::align_of::<A>() - 1usize];
};
#[repr(C)]
#[derive(Debug, Copy, Clone)]
pub struct A_I {
pub _address: u8,
}
#[allow(clippy::unnecessary_operation, clippy::identity_op)]
const _: () = {
["Size of A_I"][::std::mem::size_of::<A_I>() - 4usize];
["Alignment of A_I"][::std::mem::align_of::<A_I>() - 4usize];
};The new generated code fails to compile.
error[E0080]: attempt to compute `1_usize - 4_usize`, which would overflow
--> src/lib.rs:18:21
|
18 | ["Size of A_I"][::std::mem::size_of::<A_I>() - 4usize];
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ evaluation of `_` failed here
Notice that bindgen clearly knows that A::I is supposed to have size 4, it is just that the generated Rust type for it has size 1, and does not know what the fields are.
Input header:
Generated correct Rust binding prior to llvm/llvm-project#147835:
Generated incorrect Rust binding after that LLVM refactor, which is part of LLVM 22:
The new generated code fails to compile.
Notice that bindgen clearly knows that
A::Iis supposed to have size 4, it is just that the generated Rust type for it has size 1, and does not know what the fields are.