/*
 * Fundamental C definitions.
 */

#ifndef UTIL_LINUX_C_H
#define UTIL_LINUX_C_H

#include <limits.h>

/*
 * Compiler specific stuff
 */
#ifndef __GNUC_PREREQ
# 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
#endif

#ifdef __GNUC__

/* &a[0] degrades to a pointer: a different type from an array */
# define __must_be_array(a) \
	BUILD_BUG_ON_ZERO(__builtin_types_compatible_p(__typeof__(a), __typeof__(&a[0])))

# define ignore_result(x) ({ \
	__typeof__(x) __dummy __attribute__((__unused__)) = (x); (void) __dummy; \
})

#else /* !__GNUC__ */
# define __must_be_array(a)	0
# define __attribute__(_arg_)
# define ignore_result(x) ((void) (x))
#endif /* !__GNUC__ */

/*
 * Function attributes
 */
#ifndef __ul_alloc_size
# if __GNUC_PREREQ (4, 3)
#  define __ul_alloc_size(s) __attribute__((alloc_size(s)))
# else
#  define __ul_alloc_size(s)
# endif
#endif

#ifndef __ul_calloc_size
# if __GNUC_PREREQ (4, 3)
#  define __ul_calloc_size(n, s) __attribute__((alloc_size(n, s)))
# else
#  define __ul_calloc_size(n, s)
# endif
#endif

/* Force a compilation error if condition is true, but also produce a
 * result (of value 0 and type size_t), so the expression can be used
 * e.g. in a structure initializer (or where-ever else comma expressions
 * aren't permitted).
 */
#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))

#ifndef ARRAY_SIZE
# define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
#endif

#ifndef PATH_MAX
# define PATH_MAX 4096
#endif

#ifndef TRUE
# define TRUE 1
#endif

#ifndef FALSE
# define FALSE 0
#endif

#ifndef min
# define min(x, y) ({				\
	__typeof__(x) _min1 = (x);		\
	__typeof__(y) _min2 = (y);		\
	(void) (&_min1 == &_min2);		\
	_min1 < _min2 ? _min1 : _min2; })
#endif

#ifndef max
# define max(x, y) ({				\
	__typeof__(x) _max1 = (x);		\
	__typeof__(y) _max2 = (y);		\
	(void) (&_max1 == &_max2);		\
	_max1 > _max2 ? _max1 : _max2; })
#endif


static inline __attribute__((const)) int is_power_of_2(unsigned long num)
{
	return (num != 0 && ((num & (num - 1)) == 0));
}

#ifndef HAVE_LOFF_T
typedef int64_t loff_t;
#endif

#if !defined(HAVE_DIRFD) && (!defined(HAVE_DECL_DIRFD) || HAVE_DECL_DIRFD == 0) && defined(HAVE_DIR_DD_FD)
#include <sys/types.h>
#include <dirent.h>
static inline int dirfd(DIR *d)
{
	return d->dd_fd;
}
#endif

#ifndef HAVE_PROGRAM_INVOCATION_SHORT_NAME
# ifdef HAVE___PROGNAME
extern char *__progname;
#  define program_invocation_short_name __progname
# else
#  include <string.h>
#  ifdef HAVE_GETEXECNAME
#   include <stdlib.h>
#   define program_invocation_short_name \
		prog_inv_sh_nm_from_file(getexecname(), 0)
#  else
#   define program_invocation_short_name \
		prog_inv_sh_nm_from_file(__FILE__, 1)
#  endif
static char prog_inv_sh_nm_buf[256];
static inline char *
prog_inv_sh_nm_from_file(char *f, char stripext)
{
	char *t;

	if ((t = strrchr(f, '/')) != NULL)
		t++;
	else
		t = f;

	strncpy(prog_inv_sh_nm_buf, t, sizeof(prog_inv_sh_nm_buf) - 1);
	prog_inv_sh_nm_buf[sizeof(prog_inv_sh_nm_buf) - 1] = '\0';

	if (stripext && (t = strrchr(prog_inv_sh_nm_buf, '.')) != NULL)
		*t = '\0';

	return prog_inv_sh_nm_buf;
}
# endif
#endif

/*
 * Fallback defines for old versions of glibc
 */
#ifndef O_CLOEXEC
#define O_CLOEXEC 0
#endif

#ifndef AI_ADDRCONFIG
#define AI_ADDRCONFIG 0x0020
#endif

#ifndef IUTF8
#define IUTF8 0040000
#endif

#endif /* UTIL_LINUX_C_H */
