1 // SPDX-License-Identifier: GPL-2.0 2 3 #include <linux/build_bug.h> 4 5 /* 6 * `bindgen` binds the C `size_t` type as the Rust `usize` type, so we can 7 * use it in contexts where Rust expects a `usize` like slice (array) indices. 8 * `usize` is defined to be the same as C's `uintptr_t` type (can hold any 9 * pointer) but not necessarily the same as `size_t` (can hold the size of any 10 * single object). Most modern platforms use the same concrete integer type for 11 * both of them, but in case we find ourselves on a platform where 12 * that's not true, fail early instead of risking ABI or 13 * integer-overflow issues. 14 * 15 * If your platform fails this assertion, it means that you are in 16 * danger of integer-overflow bugs (even if you attempt to add 17 * `--no-size_t-is-usize`). It may be easiest to change the kernel ABI on 18 * your platform such that `size_t` matches `uintptr_t` (i.e., to increase 19 * `size_t`, because `uintptr_t` has to be at least as big as `size_t`). 20 */ 21 static_assert( 22 sizeof(size_t) == sizeof(uintptr_t) && 23 __alignof__(size_t) == __alignof__(uintptr_t), 24 "Rust code expects C `size_t` to match Rust `usize`" 25 ); 26