1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _TOOLS_LINUX_COMPILER_H_
3#error "Please don't include <linux/compiler-gcc.h> directly, include <linux/compiler.h> instead."
4#endif
5
6/*
7 * Common definitions for all gcc versions go here.
8 */
9#ifndef GCC_VERSION
10#define GCC_VERSION (__GNUC__ * 10000 \
11 + __GNUC_MINOR__ * 100 \
12 + __GNUC_PATCHLEVEL__)
13#endif
14
15#if __has_attribute(__fallthrough__)
16# define fallthrough __attribute__((__fallthrough__))
17#else
18# define fallthrough do {} while (0) /* fallthrough */
19#endif
20
21#if __has_attribute(__error__)
22# define __compiletime_error(message) __attribute__((error(message)))
23#endif
24
25/* &a[0] degrades to a pointer: a different type from an array */
26#define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
27
28#ifndef __pure
29#define __pure __attribute__((pure))
30#endif
31#define noinline __attribute__((noinline))
32#ifndef __packed
33#define __packed __attribute__((packed))
34#endif
35#ifndef __noreturn
36#define __noreturn __attribute__((noreturn))
37#endif
38#ifndef __aligned
39#define __aligned(x) __attribute__((aligned(x)))
40#endif
41#define __printf(a, b) __attribute__((format(printf, a, b)))
42#define __scanf(a, b) __attribute__((format(scanf, a, b)))
43

source code of linux/tools/include/linux/compiler-gcc.h