mirror of
https://github.com/rust-lang/rust.git
synced 2024-11-30 18:53:39 +00:00
64 lines
2.5 KiB
Rust
64 lines
2.5 KiB
Rust
// compile-flags: --crate-type=lib
|
|
// normalize-stderr-32bit: "8 bytes" -> "$$TWO_WORDS bytes"
|
|
// normalize-stderr-64bit: "16 bytes" -> "$$TWO_WORDS bytes"
|
|
// normalize-stderr-32bit: "size 4" -> "size $$WORD"
|
|
// normalize-stderr-64bit: "size 8" -> "size $$WORD"
|
|
|
|
#![feature(
|
|
core_intrinsics,
|
|
const_raw_ptr_comparison,
|
|
)]
|
|
|
|
const FOO: &usize = &42;
|
|
|
|
macro_rules! check {
|
|
(eq, $a:expr, $b:expr) => {
|
|
pub const _: () =
|
|
assert!(std::intrinsics::ptr_guaranteed_cmp($a as *const u8, $b as *const u8) == 1);
|
|
};
|
|
(ne, $a:expr, $b:expr) => {
|
|
pub const _: () =
|
|
assert!(std::intrinsics::ptr_guaranteed_cmp($a as *const u8, $b as *const u8) == 0);
|
|
};
|
|
(!, $a:expr, $b:expr) => {
|
|
pub const _: () =
|
|
assert!(std::intrinsics::ptr_guaranteed_cmp($a as *const u8, $b as *const u8) == 2);
|
|
};
|
|
}
|
|
|
|
check!(eq, 0, 0);
|
|
check!(ne, 0, 1);
|
|
check!(ne, FOO as *const _, 0);
|
|
check!(ne, unsafe { (FOO as *const usize).offset(1) }, 0);
|
|
check!(ne, unsafe { (FOO as *const usize as *const u8).offset(3) }, 0);
|
|
|
|
// We want pointers to be equal to themselves, but aren't checking this yet because
|
|
// there are some open questions (e.g. whether function pointers to the same function
|
|
// compare equal, they don't necessarily at runtime).
|
|
// The case tested here should work eventually, but does not work yet.
|
|
check!(!, FOO as *const _, FOO as *const _);
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
// If any of the below start compiling, make sure to add a `check` test for it.
|
|
// These invocations exist as canaries so we don't forget to check that the
|
|
// behaviour of `guaranteed_eq` and `guaranteed_ne` is still correct.
|
|
// All of these try to obtain an out of bounds pointer in some manner. If we
|
|
// can create out of bounds pointers, we can offset a pointer far enough that
|
|
// at runtime it would be zero and at compile-time it would not be zero.
|
|
|
|
const _: *const usize = unsafe { (FOO as *const usize).offset(2) };
|
|
|
|
const _: *const u8 =
|
|
unsafe { std::ptr::addr_of!((*(FOO as *const usize as *const [u8; 1000]))[999]) };
|
|
//~^ ERROR evaluation of constant value failed
|
|
//~| out-of-bounds
|
|
|
|
const _: usize = unsafe { std::mem::transmute::<*const usize, usize>(FOO) + 4 };
|
|
//~^ ERROR evaluation of constant value failed
|
|
//~| unable to turn pointer into raw bytes
|
|
|
|
const _: usize = unsafe { *std::mem::transmute::<&&usize, &usize>(&FOO) + 4 };
|
|
//~^ ERROR evaluation of constant value failed
|
|
//~| unable to turn pointer into raw bytes
|