26 lines
1.1 KiB
C
26 lines
1.1 KiB
C
|
// SPDX-License-Identifier: GPL-2.0
|
||
|
|
|
||
|
|
#include <linux/build_bug.h>
|
||
|
|
|
||
|
|
/*
|
||
|
|
* `bindgen` binds the C `size_t` type as the Rust `usize` type, so we can
|
||
|
|
* use it in contexts where Rust expects a `usize` like slice (array) indices.
|
||
|
|
* `usize` is defined to be the same as C's `uintptr_t` type (can hold any
|
||
|
|
* pointer) but not necessarily the same as `size_t` (can hold the size of any
|
||
|
|
* single object). Most modern platforms use the same concrete integer type for
|
||
|
|
* both of them, but in case we find ourselves on a platform where
|
||
|
|
* that's not true, fail early instead of risking ABI or
|
||
|
|
* integer-overflow issues.
|
||
|
|
*
|
||
|
|
* If your platform fails this assertion, it means that you are in
|
||
|
|
* danger of integer-overflow bugs (even if you attempt to add
|
||
|
|
* `--no-size_t-is-usize`). It may be easiest to change the kernel ABI on
|
||
|
|
* your platform such that `size_t` matches `uintptr_t` (i.e., to increase
|
||
|
|
* `size_t`, because `uintptr_t` has to be at least as big as `size_t`).
|
||
|
|
*/
|
||
|
|
static_assert(
|
||
|
|
sizeof(size_t) == sizeof(uintptr_t) &&
|
||
|
|
__alignof__(size_t) == __alignof__(uintptr_t),
|
||
|
|
"Rust code expects C `size_t` to match Rust `usize`"
|
||
|
|
);
|