diff options
Diffstat (limited to 'include/c.h')
| -rw-r--r-- | include/c.h | 505 |
1 files changed, 505 insertions, 0 deletions
diff --git a/include/c.h b/include/c.h new file mode 100644 index 0000000..db0c58b --- /dev/null +++ b/include/c.h @@ -0,0 +1,505 @@ +/* + * Fundamental C definitions. + * + * No copyright is claimed. This code is in the public domain; do with + * it what you wish. + */ +#ifndef UTIL_LINUX_C_H +#define UTIL_LINUX_C_H + +#include <limits.h> +#include <stddef.h> +#include <stdint.h> +#include <stdio.h> +#include <unistd.h> +#include <stdarg.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> +#include <sys/types.h> +#include <grp.h> + +#include <assert.h> + +#ifdef HAVE_ERR_H +# include <err.h> +#endif + +#ifdef HAVE_SYS_SYSMACROS_H +# include <sys/sysmacros.h> /* for major, minor */ +#endif + +#ifndef LOGIN_NAME_MAX +# define LOGIN_NAME_MAX 256 +#endif + +#ifndef NAME_MAX +# define NAME_MAX PATH_MAX +#endif + +/* + * __GNUC_PREREQ is deprecated in favour of __has_attribute() and + * __has_feature(). The __has macros are supported by clang and gcc>=5. + */ +#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) \ + UL_BUILD_BUG_ON_ZERO(__builtin_types_compatible_p(__typeof__(a), __typeof__(&a[0]))) + +# define ignore_result(x) __extension__ ({ \ + __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__ */ + + +/* "restrict" keyword fallback */ +#if __STDC__ != 1 +# define restrict __restrict /* use implementation __ format */ +#else +# ifndef __STDC_VERSION__ +# define restrict __restrict /* use implementation __ format */ +# else +# if __STDC_VERSION__ < 199901L +# define restrict __restrict /* use implementation __ format */ +# endif +# endif +#endif + + +/* + * It evaluates to 1 if the attribute/feature is supported by the current + * compilation target. Fallback for old compilers. + */ +#ifndef __has_attribute + #define __has_attribute(x) 0 +#endif + +#ifndef __has_feature + #define __has_feature(x) 0 +#endif + +/* + * Function attributes + */ +#ifndef __ul_alloc_size +# if (__has_attribute(alloc_size) && __has_attribute(warn_unused_result)) || __GNUC_PREREQ (4, 3) +# define __ul_alloc_size(s) __attribute__((alloc_size(s), warn_unused_result)) +# else +# define __ul_alloc_size(s) +# endif +#endif + +#ifndef __ul_calloc_size +# if (__has_attribute(alloc_size) && __has_attribute(warn_unused_result)) || __GNUC_PREREQ (4, 3) +# define __ul_calloc_size(n, s) __attribute__((alloc_size(n, s), warn_unused_result)) +# else +# define __ul_calloc_size(n, s) +# endif +#endif + +#if __has_attribute(returns_nonnull) || __GNUC_PREREQ (4, 9) +# define __ul_returns_nonnull __attribute__((returns_nonnull)) +#else +# define __ul_returns_nonnull +#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 wherever else comma expressions + * aren't permitted). + */ +#define UL_BUILD_BUG_ON_ZERO(e) __extension__ (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) __extension__ ({ \ + __typeof__(x) _min1 = (x); \ + __typeof__(y) _min2 = (y); \ + (void) (&_min1 == &_min2); \ + _min1 < _min2 ? _min1 : _min2; }) +#endif + +#ifndef max +# define max(x, y) __extension__ ({ \ + __typeof__(x) _max1 = (x); \ + __typeof__(y) _max2 = (y); \ + (void) (&_max1 == &_max2); \ + _max1 > _max2 ? _max1 : _max2; }) +#endif + +#ifndef abs_diff +# define abs_diff(x, y) __extension__ ({ \ + __typeof__(x) _a = (x); \ + __typeof__(y) _b = (y); \ + (void) (&_a == &_b); \ + _a > _b ? _a - _b : _b - _a; }) +#endif + +#ifndef cmp_numbers +# define cmp_numbers(x, y) __extension__ ({ \ + __typeof__(x) _a = (x); \ + __typeof__(y) _b = (y); \ + (void) (&_a == &_b); \ + _a == _b ? 0 : _a > _b ? 1 : -1; }) +#endif + + +#ifndef cmp_timespec +# define cmp_timespec(a, b, CMP) \ + (((a)->tv_sec == (b)->tv_sec) \ + ? ((a)->tv_nsec CMP (b)->tv_nsec) \ + : ((a)->tv_sec CMP (b)->tv_sec)) +#endif + + +#ifndef cmp_stat_mtime +# ifdef HAVE_STRUCT_STAT_ST_MTIM_TV_NSEC +# define cmp_stat_mtime(_a, _b, CMP) cmp_timespec(&(_a)->st_mtim, &(_b)->st_mtim, CMP) +# else +# define cmp_stat_mtime(_a, _b, CMP) ((_a)->st_mtime CMP (_b)->st_mtime) +# endif +#endif + + +#ifndef offsetof +#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER) +#endif + +/* + * container_of - cast a member of a structure out to the containing structure + * @ptr: the pointer to the member. + * @type: the type of the container struct this is embedded in. + * @member: the name of the member within the struct. + */ +#ifndef container_of +#define container_of(ptr, type, member) __extension__ ({ \ + const __typeof__( ((type *)0)->member ) *__mptr = (ptr); \ + (type *)( (char *)__mptr - offsetof(type,member) );}) +#endif + +#ifndef HAVE_PROGRAM_INVOCATION_SHORT_NAME +# ifdef HAVE___PROGNAME +extern char *__progname; +# define program_invocation_short_name __progname +# else +# ifdef HAVE_GETEXECNAME +# 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 + + +#ifndef HAVE_ERR_H +static inline void __attribute__ ((__format__ (__printf__, 4, 5))) +errmsg(char doexit, int excode, char adderr, const char *fmt, ...) +{ + fprintf(stderr, "%s: ", program_invocation_short_name); + if (fmt != NULL) { + va_list argp; + va_start(argp, fmt); + vfprintf(stderr, fmt, argp); + va_end(argp); + if (adderr) + fprintf(stderr, ": "); + } + if (adderr) + fprintf(stderr, "%m"); + fprintf(stderr, "\n"); + if (doexit) + exit(excode); +} + +#ifndef HAVE_ERR +# define err(E, FMT...) errmsg(1, E, 1, FMT) +#endif + +#ifndef HAVE_ERRX +# define errx(E, FMT...) errmsg(1, E, 0, FMT) +#endif + +#ifndef HAVE_WARN +# define warn(FMT...) errmsg(0, 0, 1, FMT) +#endif + +#ifndef HAVE_WARNX +# define warnx(FMT...) errmsg(0, 0, 0, FMT) +#endif +#endif /* !HAVE_ERR_H */ + + +/* Don't use inline function to avoid '#include "nls.h"' in c.h + */ +#define errtryhelp(eval) __extension__ ({ \ + fprintf(stderr, _("Try '%s --help' for more information.\n"), \ + program_invocation_short_name); \ + exit(eval); \ +}) + +/* After failed execvp() */ +#define EX_EXEC_FAILED 126 /* Program located, but not usable. */ +#define EX_EXEC_ENOENT 127 /* Could not find program to exec. */ +#define errexec(name) err(errno == ENOENT ? EX_EXEC_ENOENT : EX_EXEC_FAILED, \ + _("failed to execute %s"), name) + + +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 + +/* + * Fallback defines for old versions of glibc + */ +#include <fcntl.h> + +#ifdef O_CLOEXEC +#define UL_CLOEXECSTR "e" +#else +#define UL_CLOEXECSTR "" +#endif + +#ifndef O_CLOEXEC +#define O_CLOEXEC 0 +#endif + +#ifdef __FreeBSD_kernel__ +#ifndef F_DUPFD_CLOEXEC +#define F_DUPFD_CLOEXEC 17 /* Like F_DUPFD, but FD_CLOEXEC is set */ +#endif +#endif + + +#ifndef AI_ADDRCONFIG +#define AI_ADDRCONFIG 0x0020 +#endif + +#ifndef IUTF8 +#define IUTF8 0040000 +#endif + +/* + * MAXHOSTNAMELEN replacement + */ +static inline size_t get_hostname_max(void) +{ + long len = sysconf(_SC_HOST_NAME_MAX); + + if (0 < len) + return len; + +#ifdef MAXHOSTNAMELEN + return MAXHOSTNAMELEN; +#elif HOST_NAME_MAX + return HOST_NAME_MAX; +#endif + return 64; +} + + +static inline int drop_permissions(void) +{ + errno = 0; + + /* drop GID */ + if (setgid(getgid()) < 0) + goto fail; + + /* drop UID */ + if (setuid(getuid()) < 0) + goto fail; + + return 0; +fail: + return errno ? -errno : -1; +} + +/* + * The usleep function was marked obsolete in POSIX.1-2001 and was removed + * in POSIX.1-2008. It was replaced with nanosleep() that provides more + * advantages (like no interaction with signals and other timer functions). + */ +#include <time.h> + +static inline int xusleep(useconds_t usec) +{ +#ifdef HAVE_NANOSLEEP + struct timespec waittime = { + .tv_sec = usec / 1000000L, + .tv_nsec = (usec % 1000000L) * 1000 + }; + return nanosleep(&waittime, NULL); +#elif defined(HAVE_USLEEP) + return usleep(usec); +#else +# error "System with usleep() or nanosleep() required!" +#endif +} + +/* + * Constant strings for usage() functions. For more info see + * Documentation/{howto-usage-function.txt,boilerplate.c} + */ +#define USAGE_HEADER _("\nUsage:\n") +#define USAGE_OPTIONS _("\nOptions:\n") +#define USAGE_FUNCTIONS _("\nFunctions:\n") +#define USAGE_COMMANDS _("\nCommands:\n") +#define USAGE_ARGUMENTS _("\nArguments:\n") +#define USAGE_COLUMNS _("\nAvailable output columns:\n") +#define USAGE_SEPARATOR "\n" + +#define USAGE_OPTSTR_HELP _("display this help") +#define USAGE_OPTSTR_VERSION _("display version") + +#define USAGE_HELP_OPTIONS(marg_dsc) \ + "%-" #marg_dsc "s%s\n" \ + "%-" #marg_dsc "s%s\n" \ + , " -h, --help", USAGE_OPTSTR_HELP \ + , " -V, --version", USAGE_OPTSTR_VERSION + +#define USAGE_ARG_SEPARATOR "\n" +#define USAGE_ARG_SIZE(_name) \ + _(" %s arguments may be followed by the suffixes for\n" \ + " GiB, TiB, PiB, EiB, ZiB, and YiB (the \"iB\" is optional)\n"), _name + +#define USAGE_MAN_TAIL(_man) _("\nFor more details see %s.\n"), _man + +#define UTIL_LINUX_VERSION _("%s from %s\n"), program_invocation_short_name, PACKAGE_STRING + +#define print_version(eval) __extension__ ({ \ + printf(UTIL_LINUX_VERSION); \ + exit(eval); \ +}) + +/* + * seek stuff + */ +#ifndef SEEK_DATA +# define SEEK_DATA 3 +#endif +#ifndef SEEK_HOLE +# define SEEK_HOLE 4 +#endif + + +/* + * Macros to convert #define'itions to strings, for example + * #define XYXXY 42 + * printf ("%s=%s\n", stringify(XYXXY), stringify_value(XYXXY)); + */ +#define stringify_value(s) stringify(s) +#define stringify(s) #s + +/* Detect if we're compiled with Address Sanitizer + * - gcc (__SANITIZE_ADDRESS__) + * - clang (__has_feature(address_sanitizer)) + */ +#if !defined(HAS_FEATURE_ADDRESS_SANITIZER) +# ifdef __SANITIZE_ADDRESS__ +# define HAS_FEATURE_ADDRESS_SANITIZER 1 +# elif defined(__has_feature) +# if __has_feature(address_sanitizer) +# define HAS_FEATURE_ADDRESS_SANITIZER 1 +# endif +# endif +# if !defined(HAS_FEATURE_ADDRESS_SANITIZER) +# define HAS_FEATURE_ADDRESS_SANITIZER 0 +# endif +#endif + +/* + * UL_ASAN_BLACKLIST is a macro to tell AddressSanitizer (a compile-time + * instrumentation shipped with Clang and GCC) to not instrument the + * annotated function. Furthermore, it will prevent the compiler from + * inlining the function because inlining currently breaks the blacklisting + * mechanism of AddressSanitizer. + */ +#if __has_feature(address_sanitizer) && __has_attribute(no_sanitize_memory) && __has_attribute(no_sanitize_address) +# define UL_ASAN_BLACKLIST __attribute__((noinline)) __attribute__((no_sanitize_memory)) __attribute__((no_sanitize_address)) +#else +# define UL_ASAN_BLACKLIST /* nothing */ +#endif + +/* + * Note that sysconf(_SC_GETPW_R_SIZE_MAX) returns *initial* suggested size for + * pwd buffer and in some cases it is not large enough. See POSIX and + * getpwnam_r man page for more details. + */ +#define UL_GETPW_BUFSIZ (16 * 1024) + +/* + * Darwin or other BSDs may only have MAP_ANON. To get it on Darwin we must + * define _DARWIN_C_SOURCE before including sys/mman.h. We do this in config.h. + */ +#if !defined MAP_ANONYMOUS && defined MAP_ANON +# define MAP_ANONYMOUS (MAP_ANON) +#endif + +#endif /* UTIL_LINUX_C_H */ |