// Issue #80127: Passing structs via FFI should work with explicit alignment. use std::ffi::{CStr, c_char}; use std::ptr::null_mut; #[derive(Copy, Clone)] #[repr(C)] pub struct BoolAndU32 { pub a: bool, pub b: u32, } #[derive(Copy, Clone)] #[repr(C)] #[repr(align(16))] pub struct TwoU64s { pub a: u64, pub b: u64, } #[derive(Copy, Clone)] #[repr(C)] pub struct WrappedU64s { pub a: TwoU64s } #[derive(Copy, Clone)] #[repr(C)] // Even though requesting align 1 can never change the alignment, it still affects the ABI // on some platforms like i686-windows. #[repr(align(1))] pub struct LowerAlign { pub a: u64, pub b: u64, } #[derive(Copy, Clone)] #[repr(C)] #[repr(packed)] pub struct Packed { pub a: u128 } #[link(name = "test", kind = "static")] extern "C" { fn many_args( a: *mut (), b: *mut (), c: *const c_char, d: u64, e: bool, f: BoolAndU32, g: *mut (), h: TwoU64s, i: *mut (), j: WrappedU64s, k: *mut (), l: LowerAlign, m: *mut (), n: Packed, o: *const c_char, ) -> i32; } const STRING: &CStr = unsafe { CStr::from_bytes_with_nul_unchecked(b"Hello world\0") }; fn main() { let bool_and_u32 = BoolAndU32 { a: true, b: 1337 }; let two_u64s = TwoU64s { a: 1, b: 2 }; let wrapped = WrappedU64s { a: TwoU64s { a: 3, b: 4 } }; let lower = LowerAlign { a: 5, b: 6 }; let packed = Packed { a: 7 }; let string = STRING; unsafe { many_args( null_mut(), null_mut(), null_mut(), 42, true, bool_and_u32, null_mut(), two_u64s, null_mut(), wrapped, null_mut(), lower, null_mut(), packed, string.as_ptr(), ); } }