diff options
Diffstat (limited to 'src/test/run-pass/packed-struct-optimized-enum.rs')
| -rw-r--r-- | src/test/run-pass/packed-struct-optimized-enum.rs | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/src/test/run-pass/packed-struct-optimized-enum.rs b/src/test/run-pass/packed-struct-optimized-enum.rs new file mode 100644 index 00000000000..876b74a042f --- /dev/null +++ b/src/test/run-pass/packed-struct-optimized-enum.rs @@ -0,0 +1,29 @@ +// Copyright 2017 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +#[repr(packed)] +struct Packed<T: Copy>(T); + +impl<T: Copy> Copy for Packed<T> {} +impl<T: Copy> Clone for Packed<T> { + fn clone(&self) -> Self { *self } +} + +fn main() { + let one = (Some(Packed((&(), 0))), true); + let two = [one, one]; + let stride = (&two[1] as *const _ as usize) - (&two[0] as *const _ as usize); + + // This can fail if rustc and LLVM disagree on the size of a type. + // In this case, `Option<Packed<(&(), u32)>>` was erronously not + // marked as packed despite needing alignment `1` and containing + // its `&()` discriminant, which has alignment larger than `1`. + assert_eq!(stride, std::mem::size_of_val(&one)); +} |
