Openwrt/toolchain/musl/include/features.h

#ifndef _FEATURES_H
#define _FEATURES_H

#ifdef _ALL_SOURCE
#define _GNU_SOURCE 1
#endif

#if !defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE) \
 && !defined(_XOPEN_SOURCE) && !defined(_GNU_SOURCE) \
 && !defined(_BSD_SOURCE) && !defined(__STRICT_ANSI__)
#define _BSD_SOURCE 1
#define _XOPEN_SOURCE 700
#endif

#if __STDC_VERSION__ >= 199901L
#define __restrict restrict
#elif !defined(__GNUC__)
#define __restrict
#endif

#if __STDC_VERSION__ >= 199901L || defined(__cplusplus)
#define __inline inline
#endif

#if __STDC_VERSION__ >= 201112L
#elif defined(__GNUC__)
#define _Noreturn __attribute__((__noreturn__))
#else
#define _Noreturn
#endif

/* Convenience macros to test the versions of glibc and gcc.
   Use them like this:
   #if __GNUC_PREREQ (2,8)
   ... code requiring gcc 2.8 or later ...
   #endif
   Note - they won't work for gcc1 or glibc1, since the _MINOR macros
   were not defined then.  */
#if defined __GNUC__ && defined __GNUC_MINOR__
# define __GNUC_PREREQ(maj, min) \
	((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
#else
# define __GNUC_PREREQ(maj, min) 0
#endif

#if !defined __FORCE_NOGLIBC && (!defined _LIBC || defined __FORCE_GLIBC)
#undef __GNU_LIBRARY__
#define __GNU_LIBRARY__ 6

#define __GLIBC__ 2
#define __GLIBC_MINOR__ 2
#endif

#include <sys/glibc-types.h>

#endif