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