src/test/ui/abi/issues/issue-97463-broken-abi-leaked-uninit-data.rs

   1 // run-pass
   2 // ignore-wasm
   3 #![allow(dead_code)]
   4 #![allow(improper_ctypes)]
   5
   6 #[link(name = "rust_test_helpers", kind = "static")]
   7 extern "C" {
   8     pub fn issue_97463_leak_uninit_data(a: u32, b: u32, c: u32) -> u16;
   9 }
  10
  11 fn main() {
  12     const C1: usize = 0x327b23c6;
  13     const C2: usize = C1 & 0xFFFF;
  14
  15     let r1: usize = 0x0;
  16     let r2: usize = C1;
  17     let r3: usize = 0x0;
  18     let value: u16 = unsafe { issue_97463_leak_uninit_data(r1 as u32, r2 as u32, r3 as u32) };
  19
  20     // NOTE: as an example of the sensitivity of this test to optimization choices,
  21     // uncommenting this block of code makes the bug go away on pnkfelix's machine.
  22     // (But observing via `dbg!` doesn't hide the bug. At least sometimes.)
  23     /*
  24     println!("{}", value);
  25     println!("{}", value as usize);
  26     println!("{}", usize::from(value));
  27     println!("{}", (value as usize) & 0xFFFF);
  28      */
  29
  30     let d1 = value;
  31     let d2 = value as usize;
  32     let d3 = usize::from(value);
  33     let d4 = (value as usize) & 0xFFFF;
  34
  35     let d = (&d1, &d2, &d3, &d4);
  36     let d_ = (d1, d2, d3, d4);
  37
  38     assert_eq!(((&(C2 as u16), &C2, &C2, &C2), (C2 as u16, C2, C2, C2)), (d, d_));
  39 }