Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
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linux
1#ifndef __LINUX_COMPILER_H
2#error "Please don't include <linux/compiler-gcc.h> directly, include <linux/compiler.h> instead."
3#endif
4
5/*
6 * Common definitions for all gcc versions go here.
7 */
8
9
10/* Optimization barrier */
11/* The "volatile" is due to gcc bugs */
12#define barrier() __asm__ __volatile__("": : :"memory")
13
14/* This macro obfuscates arithmetic on a variable address so that gcc
15 shouldn't recognize the original var, and make assumptions about it */
16/*
17 * Versions of the ppc64 compiler before 4.1 had a bug where use of
18 * RELOC_HIDE could trash r30. The bug can be worked around by changing
19 * the inline assembly constraint from =g to =r, in this particular
20 * case either is valid.
21 */
22#define RELOC_HIDE(ptr, off) \
23 ({ unsigned long __ptr; \
24 __asm__ ("" : "=r"(__ptr) : "0"(ptr)); \
25 (typeof(ptr)) (__ptr + (off)); })
26
27/* &a[0] degrades to a pointer: a different type from an array */
28#define __must_be_array(a) \
29 BUILD_BUG_ON_ZERO(__builtin_types_compatible_p(typeof(a), typeof(&a[0])))
30
31#define inline inline __attribute__((always_inline))
32#define __inline__ __inline__ __attribute__((always_inline))
33#define __inline __inline __attribute__((always_inline))
34#define __deprecated __attribute__((deprecated))
35#define __packed __attribute__((packed))
36#define __weak __attribute__((weak))
37#define __naked __attribute__((naked))
38#define __noreturn __attribute__((noreturn))
39
40/*
41 * From the GCC manual:
42 *
43 * Many functions have no effects except the return value and their
44 * return value depends only on the parameters and/or global
45 * variables. Such a function can be subject to common subexpression
46 * elimination and loop optimization just as an arithmetic operator
47 * would be.
48 * [...]
49 */
50#define __pure __attribute__((pure))
51#define __aligned(x) __attribute__((aligned(x)))
52#define __printf(a,b) __attribute__((format(printf,a,b)))
53#define noinline __attribute__((noinline))
54#define __attribute_const__ __attribute__((__const__))
55#define __maybe_unused __attribute__((unused))