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//@ run-pass
#![allow(dead_code)]
/*!
* C-like enums have to be represented as LLVM ints, not wrapped in a
* struct, because it's important for the FFI that they interoperate
* with C integers/enums, and the ABI can treat structs differently.
* For example, on i686-linux-gnu, a struct return value is passed by
* storing to a hidden out parameter, whereas an integer would be
* returned in a register.
*
* This test just checks that the ABIs for the enum and the plain
* integer are compatible, rather than actually calling C code.
* The unused parameter to `foo` is to increase the likelihood of
* crashing if something goes wrong here.
*/
#[repr(u32)]
enum Foo {
A = 0,
B = 23
}
#[inline(never)]
extern "C" fn foo(_x: usize) -> Foo { Foo::B }
pub fn main() {
unsafe {
let f: extern "C" fn(usize) -> u32 =
::std::mem::transmute(foo as extern "C" fn(usize) -> Foo);
assert_eq!(f(0xDEADBEEF), Foo::B as u32);
}
}
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