src/test/run-pass/issue-32947.rs

   1 // Copyright 2016 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 #![feature(repr_simd, test)]
  12
  13 extern crate test;
  14
  15 #[repr(simd)]
  16 pub struct Mu64(pub u64, pub u64, pub u64, pub u64);
  17
  18 fn main() {
  19     // This ensures an unaligned pointer even in optimized builds, though LLVM
  20     // gets enough type information to actually not mess things up in that case,
  21     // but at the time of writing this, it's enough to trigger the bug in
  22     // non-optimized builds
  23     unsafe {
  24         let memory = &mut [0u64; 8] as *mut _ as *mut u8;
  25         let misaligned_ptr: &mut [u8; 32] = {
  26             std::mem::transmute(memory.offset(1))
  27         };
  28         *misaligned_ptr = std::mem::transmute(Mu64(1, 1, 1, 1));
  29         test::black_box(memory);
  30     }
  31 }