src/test/ui/abi/union/union-c-interop.rs

   1 // run-pass
   2 #![allow(non_snake_case)]
   3
   4 // ignore-wasm32-bare no libc to test ffi with
   5
   6 #[derive(Clone, Copy)]
   7 #[repr(C)]
   8 struct LARGE_INTEGER_U {
   9     LowPart: u32,
  10     HighPart: u32,
  11 }
  12
  13 #[derive(Clone, Copy)]
  14 #[repr(C)]
  15 union LARGE_INTEGER {
  16   __unnamed__: LARGE_INTEGER_U,
  17   u: LARGE_INTEGER_U,
  18   QuadPart: u64,
  19 }
  20
  21 #[link(name = "rust_test_helpers", kind = "static")]
  22 extern "C" {
  23     fn increment_all_parts(_: LARGE_INTEGER) -> LARGE_INTEGER;
  24 }
  25
  26 fn main() {
  27     unsafe {
  28         let mut li = LARGE_INTEGER { QuadPart: 0 };
  29         let li_c = increment_all_parts(li);
  30         li.__unnamed__.LowPart += 1;
  31         li.__unnamed__.HighPart += 1;
  32         li.u.LowPart += 1;
  33         li.u.HighPart += 1;
  34         li.QuadPart += 1;
  35         assert_eq!(li.QuadPart, li_c.QuadPart);
  36     }
  37 }