git-compat-util.h

   1 #ifndef GIT_COMPAT_UTIL_H
   2 #define GIT_COMPAT_UTIL_H
   3
   4 #ifdef USE_MSVC_CRTDBG
   5 /*
   6  * For these to work they must appear very early in each
   7  * file -- before most of the standard header files.
   8  */
   9 #include <stdlib.h>
  10 #include <crtdbg.h>
  11 #endif
  12
  13 #define _FILE_OFFSET_BITS 64
  14
  15
  16 /* Derived from Linux "Features Test Macro" header
  17  * Convenience macros to test the versions of gcc (or
  18  * a compatible compiler).
  19  * Use them like this:
  20  *  #if GIT_GNUC_PREREQ (2,8)
  21  *   ... code requiring gcc 2.8 or later ...
  22  *  #endif
  23 */
  24 #if defined(__GNUC__) && defined(__GNUC_MINOR__)
  25 # define GIT_GNUC_PREREQ(maj, min) \
  26         ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
  27 #else
  28  #define GIT_GNUC_PREREQ(maj, min) 0
  29 #endif
  30
  31
  32 #ifndef FLEX_ARRAY
  33 /*
  34  * See if our compiler is known to support flexible array members.
  35  */
  36 #if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) && (!defined(__SUNPRO_C) || (__SUNPRO_C > 0x580))
  37 # define FLEX_ARRAY /* empty */
  38 #elif defined(__GNUC__)
  39 # if (__GNUC__ >= 3)
  40 #  define FLEX_ARRAY /* empty */
  41 # else
  42 #  define FLEX_ARRAY 0 /* older GNU extension */
  43 # endif
  44 #endif
  45
  46 /*
  47  * Otherwise, default to safer but a bit wasteful traditional style
  48  */
  49 #ifndef FLEX_ARRAY
  50 # define FLEX_ARRAY 1
  51 #endif
  52 #endif
  53
  54
  55 /*
  56  * BUILD_ASSERT_OR_ZERO - assert a build-time dependency, as an expression.
  57  * @cond: the compile-time condition which must be true.
  58  *
  59  * Your compile will fail if the condition isn't true, or can't be evaluated
  60  * by the compiler.  This can be used in an expression: its value is "0".
  61  *
  62  * Example:
  63  *      #define foo_to_char(foo)                                        \
  64  *               ((char *)(foo)                                         \
  65  *                + BUILD_ASSERT_OR_ZERO(offsetof(struct foo, string) == 0))
  66  */
  67 #define BUILD_ASSERT_OR_ZERO(cond) \
  68         (sizeof(char [1 - 2*!(cond)]) - 1)
  69
  70 #if GIT_GNUC_PREREQ(3, 1)
  71  /* &arr[0] degrades to a pointer: a different type from an array */
  72 # define BARF_UNLESS_AN_ARRAY(arr)                                              \
  73         BUILD_ASSERT_OR_ZERO(!__builtin_types_compatible_p(__typeof__(arr), \
  74                                                            __typeof__(&(arr)[0])))
  75 #else
  76 # define BARF_UNLESS_AN_ARRAY(arr) 0
  77 #endif
  78 /*
  79  * ARRAY_SIZE - get the number of elements in a visible array
  80  * @x: the array whose size you want.
  81  *
  82  * This does not work on pointers, or arrays declared as [], or
  83  * function parameters.  With correct compiler support, such usage
  84  * will cause a build error (see the build_assert_or_zero macro).
  85  */
  86 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]) + BARF_UNLESS_AN_ARRAY(x))
  87
  88 #define bitsizeof(x)  (CHAR_BIT * sizeof(x))
  89
  90 #define maximum_signed_value_of_type(a) \
  91     (INTMAX_MAX >> (bitsizeof(intmax_t) - bitsizeof(a)))
  92
  93 #define maximum_unsigned_value_of_type(a) \
  94     (UINTMAX_MAX >> (bitsizeof(uintmax_t) - bitsizeof(a)))
  95
  96 /*
  97  * Signed integer overflow is undefined in C, so here's a helper macro
  98  * to detect if the sum of two integers will overflow.
  99  *
 100  * Requires: a >= 0, typeof(a) equals typeof(b)
 101  */
 102 #define signed_add_overflows(a, b) \
 103     ((b) > maximum_signed_value_of_type(a) - (a))
 104
 105 #define unsigned_add_overflows(a, b) \
 106     ((b) > maximum_unsigned_value_of_type(a) - (a))
 107
 108 /*
 109  * Returns true if the multiplication of "a" and "b" will
 110  * overflow. The types of "a" and "b" must match and must be unsigned.
 111  * Note that this macro evaluates "a" twice!
 112  */
 113 #define unsigned_mult_overflows(a, b) \
 114     ((a) && (b) > maximum_unsigned_value_of_type(a) / (a))
 115
 116 /*
 117  * Returns true if the left shift of "a" by "shift" bits will
 118  * overflow. The type of "a" must be unsigned.
 119  */
 120 #define unsigned_left_shift_overflows(a, shift) \
 121     ((shift) < bitsizeof(a) && \
 122      (a) > maximum_unsigned_value_of_type(a) >> (shift))
 123
 124 #ifdef __GNUC__
 125 #define TYPEOF(x) (__typeof__(x))
 126 #else
 127 #define TYPEOF(x)
 128 #endif
 129
 130 #define MSB(x, bits) ((x) & TYPEOF(x)(~0ULL << (bitsizeof(x) - (bits))))
 131 #define HAS_MULTI_BITS(i)  ((i) & ((i) - 1))  /* checks if an integer has more than 1 bit set */
 132
 133 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
 134
 135 /* Approximation of the length of the decimal representation of this type. */
 136 #define decimal_length(x)       ((int)(sizeof(x) * 2.56 + 0.5) + 1)
 137
 138 #if defined(__sun__)
 139  /*
 140   * On Solaris, when _XOPEN_EXTENDED is set, its header file
 141   * forces the programs to be XPG4v2, defeating any _XOPEN_SOURCE
 142   * setting to say we are XPG5 or XPG6.  Also on Solaris,
 143   * XPG6 programs must be compiled with a c99 compiler, while
 144   * non XPG6 programs must be compiled with a pre-c99 compiler.
 145   */
 146 # if __STDC_VERSION__ - 0 >= 199901L
 147 # define _XOPEN_SOURCE 600
 148 # else
 149 # define _XOPEN_SOURCE 500
 150 # endif
 151 #elif !defined(__APPLE__) && !defined(__FreeBSD__) && !defined(__USLC__) && \
 152       !defined(_M_UNIX) && !defined(__sgi) && !defined(__DragonFly__) && \
 153       !defined(__TANDEM) && !defined(__QNX__) && !defined(__MirBSD__) && \
 154       !defined(__CYGWIN__)
 155 #define _XOPEN_SOURCE 600 /* glibc2 and AIX 5.3L need 500, OpenBSD needs 600 for S_ISLNK() */
 156 #define _XOPEN_SOURCE_EXTENDED 1 /* AIX 5.3L needs this */
 157 #endif
 158 #define _ALL_SOURCE 1
 159 #define _GNU_SOURCE 1
 160 #define _BSD_SOURCE 1
 161 #define _DEFAULT_SOURCE 1
 162 #define _NETBSD_SOURCE 1
 163 #define _SGI_SOURCE 1
 164
 165 #if defined(WIN32) && !defined(__CYGWIN__) /* Both MinGW and MSVC */
 166 # if !defined(_WIN32_WINNT)
 167 #  define _WIN32_WINNT 0x0600
 168 # endif
 169 #define WIN32_LEAN_AND_MEAN  /* stops windows.h including winsock.h */
 170 #include <winsock2.h>
 171 #ifndef NO_UNIX_SOCKETS
 172 #include <afunix.h>
 173 #endif
 174 #include <windows.h>
 175 #define GIT_WINDOWS_NATIVE
 176 #endif
 177
 178 #include <unistd.h>
 179 #include <stdio.h>
 180 #include <sys/stat.h>
 181 #include <fcntl.h>
 182 #include <stddef.h>
 183 #include <stdlib.h>
 184 #include <stdarg.h>
 185 #include <string.h>
 186 #ifdef HAVE_STRINGS_H
 187 #include <strings.h> /* for strcasecmp() */
 188 #endif
 189 #include <errno.h>
 190 #include <limits.h>
 191 #ifdef NEEDS_SYS_PARAM_H
 192 #include <sys/param.h>
 193 #endif
 194 #include <sys/types.h>
 195 #include <dirent.h>
 196 #include <sys/time.h>
 197 #include <time.h>
 198 #include <signal.h>
 199 #include <assert.h>
 200 #include <regex.h>
 201 #include <utime.h>
 202 #include <syslog.h>
 203 #if !defined(NO_POLL_H)
 204 #include <poll.h>
 205 #elif !defined(NO_SYS_POLL_H)
 206 #include <sys/poll.h>
 207 #else
 208 /* Pull the compat stuff */
 209 #include <poll.h>
 210 #endif
 211 #ifdef HAVE_BSD_SYSCTL
 212 #include <sys/sysctl.h>
 213 #endif
 214
 215 #if defined(__CYGWIN__)
 216 #include "compat/win32/path-utils.h"
 217 #endif
 218 #if defined(__MINGW32__)
 219 /* pull in Windows compatibility stuff */
 220 #include "compat/win32/path-utils.h"
 221 #include "compat/mingw.h"
 222 #elif defined(_MSC_VER)
 223 #include "compat/win32/path-utils.h"
 224 #include "compat/msvc.h"
 225 #else
 226 #include <sys/utsname.h>
 227 #include <sys/wait.h>
 228 #include <sys/resource.h>
 229 #include <sys/socket.h>
 230 #include <sys/ioctl.h>
 231 #include <termios.h>
 232 #ifndef NO_SYS_SELECT_H
 233 #include <sys/select.h>
 234 #endif
 235 #include <netinet/in.h>
 236 #include <netinet/tcp.h>
 237 #include <arpa/inet.h>
 238 #include <netdb.h>
 239 #include <pwd.h>
 240 #include <sys/un.h>
 241 #ifndef NO_INTTYPES_H
 242 #include <inttypes.h>
 243 #else
 244 #include <stdint.h>
 245 #endif
 246 #ifdef NO_INTPTR_T
 247 /*
 248  * On I16LP32, ILP32 and LP64 "long" is the safe bet, however
 249  * on LLP86, IL33LLP64 and P64 it needs to be "long long",
 250  * while on IP16 and IP16L32 it is "int" (resp. "short")
 251  * Size needs to match (or exceed) 'sizeof(void *)'.
 252  * We can't take "long long" here as not everybody has it.
 253  */
 254 typedef long intptr_t;
 255 typedef unsigned long uintptr_t;
 256 #endif
 257 #undef _ALL_SOURCE /* AIX 5.3L defines a struct list with _ALL_SOURCE. */
 258 #include <grp.h>
 259 #define _ALL_SOURCE 1
 260 #endif
 261
 262 /* used on Mac OS X */
 263 #ifdef PRECOMPOSE_UNICODE
 264 #include "compat/precompose_utf8.h"
 265 #else
 266 static inline const char *precompose_argv_prefix(int argc, const char **argv, const char *prefix)
 267 {
 268         return prefix;
 269 }
 270 static inline const char *precompose_string_if_needed(const char *in)
 271 {
 272         return in;
 273 }
 274
 275 #define probe_utf8_pathname_composition()
 276 #endif
 277
 278 #ifdef MKDIR_WO_TRAILING_SLASH
 279 #define mkdir(a,b) compat_mkdir_wo_trailing_slash((a),(b))
 280 int compat_mkdir_wo_trailing_slash(const char*, mode_t);
 281 #endif
 282
 283 #ifdef NO_STRUCT_ITIMERVAL
 284 struct itimerval {
 285         struct timeval it_interval;
 286         struct timeval it_value;
 287 };
 288 #endif
 289
 290 #ifdef NO_SETITIMER
 291 static inline int setitimer(int which, const struct itimerval *value, struct itimerval *newvalue) {
 292         return 0; /* pretend success */
 293 }
 294 #endif
 295
 296 #ifndef NO_LIBGEN_H
 297 #include <libgen.h>
 298 #else
 299 #define basename gitbasename
 300 char *gitbasename(char *);
 301 #define dirname gitdirname
 302 char *gitdirname(char *);
 303 #endif
 304
 305 #ifndef NO_ICONV
 306 #include <iconv.h>
 307 #endif
 308
 309 #ifndef NO_OPENSSL
 310 #ifdef __APPLE__
 311 #define __AVAILABILITY_MACROS_USES_AVAILABILITY 0
 312 #include <AvailabilityMacros.h>
 313 #undef DEPRECATED_ATTRIBUTE
 314 #define DEPRECATED_ATTRIBUTE
 315 #undef __AVAILABILITY_MACROS_USES_AVAILABILITY
 316 #endif
 317 #include <openssl/ssl.h>
 318 #include <openssl/err.h>
 319 #endif
 320
 321 #ifdef HAVE_SYSINFO
 322 # include <sys/sysinfo.h>
 323 #endif
 324
 325 /* On most systems <netdb.h> would have given us this, but
 326  * not on some systems (e.g. z/OS).
 327  */
 328 #ifndef NI_MAXHOST
 329 #define NI_MAXHOST 1025
 330 #endif
 331
 332 #ifndef NI_MAXSERV
 333 #define NI_MAXSERV 32
 334 #endif
 335
 336 /* On most systems <limits.h> would have given us this, but
 337  * not on some systems (e.g. GNU/Hurd).
 338  */
 339 #ifndef PATH_MAX
 340 #define PATH_MAX 4096
 341 #endif
 342
 343 typedef uintmax_t timestamp_t;
 344 #define PRItime PRIuMAX
 345 #define parse_timestamp strtoumax
 346 #define TIME_MAX UINTMAX_MAX
 347 #define TIME_MIN 0
 348
 349 #ifndef PATH_SEP
 350 #define PATH_SEP ':'
 351 #endif
 352
 353 #ifdef HAVE_PATHS_H
 354 #include <paths.h>
 355 #endif
 356 #ifndef _PATH_DEFPATH
 357 #define _PATH_DEFPATH "/usr/local/bin:/usr/bin:/bin"
 358 #endif
 359
 360 #ifndef platform_core_config
 361 static inline int noop_core_config(const char *var, const char *value, void *cb)
 362 {
 363         return 0;
 364 }
 365 #define platform_core_config noop_core_config
 366 #endif
 367
 368 int lstat_cache_aware_rmdir(const char *path);
 369 #if !defined(__MINGW32__) && !defined(_MSC_VER)
 370 #define rmdir lstat_cache_aware_rmdir
 371 #endif
 372
 373 #ifndef has_dos_drive_prefix
 374 static inline int git_has_dos_drive_prefix(const char *path)
 375 {
 376         return 0;
 377 }
 378 #define has_dos_drive_prefix git_has_dos_drive_prefix
 379 #endif
 380
 381 #ifndef skip_dos_drive_prefix
 382 static inline int git_skip_dos_drive_prefix(char **path)
 383 {
 384         return 0;
 385 }
 386 #define skip_dos_drive_prefix git_skip_dos_drive_prefix
 387 #endif
 388
 389 #ifndef is_dir_sep
 390 static inline int git_is_dir_sep(int c)
 391 {
 392         return c == '/';
 393 }
 394 #define is_dir_sep git_is_dir_sep
 395 #endif
 396
 397 #ifndef offset_1st_component
 398 static inline int git_offset_1st_component(const char *path)
 399 {
 400         return is_dir_sep(path[0]);
 401 }
 402 #define offset_1st_component git_offset_1st_component
 403 #endif
 404
 405 #ifndef is_valid_path
 406 #define is_valid_path(path) 1
 407 #endif
 408
 409 #ifndef find_last_dir_sep
 410 static inline char *git_find_last_dir_sep(const char *path)
 411 {
 412         return strrchr(path, '/');
 413 }
 414 #define find_last_dir_sep git_find_last_dir_sep
 415 #endif
 416
 417 #ifndef has_dir_sep
 418 static inline int git_has_dir_sep(const char *path)
 419 {
 420         return !!strchr(path, '/');
 421 }
 422 #define has_dir_sep(path) git_has_dir_sep(path)
 423 #endif
 424
 425 #ifndef query_user_email
 426 #define query_user_email() NULL
 427 #endif
 428
 429 #ifdef __TANDEM
 430 #include <floss.h(floss_execl,floss_execlp,floss_execv,floss_execvp)>
 431 #include <floss.h(floss_getpwuid)>
 432 #ifndef NSIG
 433 /*
 434  * NonStop NSE and NSX do not provide NSIG. SIGGUARDIAN(99) is the highest
 435  * known, by detective work using kill -l as a list is all signals
 436  * instead of signal.h where it should be.
 437  */
 438 # define NSIG 100
 439 #endif
 440 #endif
 441
 442 #if defined(__HP_cc) && (__HP_cc >= 61000)
 443 #define NORETURN __attribute__((noreturn))
 444 #define NORETURN_PTR
 445 #elif defined(__GNUC__) && !defined(NO_NORETURN)
 446 #define NORETURN __attribute__((__noreturn__))
 447 #define NORETURN_PTR __attribute__((__noreturn__))
 448 #elif defined(_MSC_VER)
 449 #define NORETURN __declspec(noreturn)
 450 #define NORETURN_PTR
 451 #else
 452 #define NORETURN
 453 #define NORETURN_PTR
 454 #ifndef __GNUC__
 455 #ifndef __attribute__
 456 #define __attribute__(x)
 457 #endif
 458 #endif
 459 #endif
 460
 461 /* The sentinel attribute is valid from gcc version 4.0 */
 462 #if defined(__GNUC__) && (__GNUC__ >= 4)
 463 #define LAST_ARG_MUST_BE_NULL __attribute__((sentinel))
 464 #else
 465 #define LAST_ARG_MUST_BE_NULL
 466 #endif
 467
 468 #define MAYBE_UNUSED __attribute__((__unused__))
 469
 470 #include "compat/bswap.h"
 471
 472 #include "wildmatch.h"
 473
 474 struct strbuf;
 475
 476 /* General helper functions */
 477 void vreportf(const char *prefix, const char *err, va_list params);
 478 NORETURN void usage(const char *err);
 479 NORETURN void usagef(const char *err, ...) __attribute__((format (printf, 1, 2)));
 480 NORETURN void die(const char *err, ...) __attribute__((format (printf, 1, 2)));
 481 NORETURN void die_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
 482 int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
 483 int error_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
 484 void warning(const char *err, ...) __attribute__((format (printf, 1, 2)));
 485 void warning_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
 486
 487 #ifndef NO_OPENSSL
 488 #ifdef APPLE_COMMON_CRYPTO
 489 #include "compat/apple-common-crypto.h"
 490 #else
 491 #include <openssl/evp.h>
 492 #include <openssl/hmac.h>
 493 #endif /* APPLE_COMMON_CRYPTO */
 494 #include <openssl/x509v3.h>
 495 #endif /* NO_OPENSSL */
 496
 497 /*
 498  * Let callers be aware of the constant return value; this can help
 499  * gcc with -Wuninitialized analysis. We restrict this trick to gcc, though,
 500  * because some compilers may not support variadic macros. Since we're only
 501  * trying to help gcc, anyway, it's OK; other compilers will fall back to
 502  * using the function as usual.
 503  */
 504 #if defined(__GNUC__)
 505 static inline int const_error(void)
 506 {
 507         return -1;
 508 }
 509 #define error(...) (error(__VA_ARGS__), const_error())
 510 #define error_errno(...) (error_errno(__VA_ARGS__), const_error())
 511 #endif
 512
 513 typedef void (*report_fn)(const char *, va_list params);
 514
 515 void set_die_routine(NORETURN_PTR report_fn routine);
 516 void set_error_routine(report_fn routine);
 517 report_fn get_error_routine(void);
 518 void set_warn_routine(report_fn routine);
 519 report_fn get_warn_routine(void);
 520 void set_die_is_recursing_routine(int (*routine)(void));
 521
 522 int starts_with(const char *str, const char *prefix);
 523 int istarts_with(const char *str, const char *prefix);
 524
 525 /*
 526  * If the string "str" begins with the string found in "prefix", return 1.
 527  * The "out" parameter is set to "str + strlen(prefix)" (i.e., to the point in
 528  * the string right after the prefix).
 529  *
 530  * Otherwise, return 0 and leave "out" untouched.
 531  *
 532  * Examples:
 533  *
 534  *   [extract branch name, fail if not a branch]
 535  *   if (!skip_prefix(ref, "refs/heads/", &branch)
 536  *      return -1;
 537  *
 538  *   [skip prefix if present, otherwise use whole string]
 539  *   skip_prefix(name, "refs/heads/", &name);
 540  */
 541 static inline int skip_prefix(const char *str, const char *prefix,
 542                               const char **out)
 543 {
 544         do {
 545                 if (!*prefix) {
 546                         *out = str;
 547                         return 1;
 548                 }
 549         } while (*str++ == *prefix++);
 550         return 0;
 551 }
 552
 553 /*
 554  * If the string "str" is the same as the string in "prefix", then the "arg"
 555  * parameter is set to the "def" parameter and 1 is returned.
 556  * If the string "str" begins with the string found in "prefix" and then a
 557  * "=" sign, then the "arg" parameter is set to "str + strlen(prefix) + 1"
 558  * (i.e., to the point in the string right after the prefix and the "=" sign),
 559  * and 1 is returned.
 560  *
 561  * Otherwise, return 0 and leave "arg" untouched.
 562  *
 563  * When we accept both a "--key" and a "--key=<val>" option, this function
 564  * can be used instead of !strcmp(arg, "--key") and then
 565  * skip_prefix(arg, "--key=", &arg) to parse such an option.
 566  */
 567 int skip_to_optional_arg_default(const char *str, const char *prefix,
 568                                  const char **arg, const char *def);
 569
 570 static inline int skip_to_optional_arg(const char *str, const char *prefix,
 571                                        const char **arg)
 572 {
 573         return skip_to_optional_arg_default(str, prefix, arg, "");
 574 }
 575
 576 /*
 577  * Like skip_prefix, but promises never to read past "len" bytes of the input
 578  * buffer, and returns the remaining number of bytes in "out" via "outlen".
 579  */
 580 static inline int skip_prefix_mem(const char *buf, size_t len,
 581                                   const char *prefix,
 582                                   const char **out, size_t *outlen)
 583 {
 584         size_t prefix_len = strlen(prefix);
 585         if (prefix_len <= len && !memcmp(buf, prefix, prefix_len)) {
 586                 *out = buf + prefix_len;
 587                 *outlen = len - prefix_len;
 588                 return 1;
 589         }
 590         return 0;
 591 }
 592
 593 /*
 594  * If buf ends with suffix, return 1 and subtract the length of the suffix
 595  * from *len. Otherwise, return 0 and leave *len untouched.
 596  */
 597 static inline int strip_suffix_mem(const char *buf, size_t *len,
 598                                    const char *suffix)
 599 {
 600         size_t suflen = strlen(suffix);
 601         if (*len < suflen || memcmp(buf + (*len - suflen), suffix, suflen))
 602                 return 0;
 603         *len -= suflen;
 604         return 1;
 605 }
 606
 607 /*
 608  * If str ends with suffix, return 1 and set *len to the size of the string
 609  * without the suffix. Otherwise, return 0 and set *len to the size of the
 610  * string.
 611  *
 612  * Note that we do _not_ NUL-terminate str to the new length.
 613  */
 614 static inline int strip_suffix(const char *str, const char *suffix, size_t *len)
 615 {
 616         *len = strlen(str);
 617         return strip_suffix_mem(str, len, suffix);
 618 }
 619
 620 static inline int ends_with(const char *str, const char *suffix)
 621 {
 622         size_t len;
 623         return strip_suffix(str, suffix, &len);
 624 }
 625
 626 #define SWAP(a, b) do {                                         \
 627         void *_swap_a_ptr = &(a);                               \
 628         void *_swap_b_ptr = &(b);                               \
 629         unsigned char _swap_buffer[sizeof(a)];                  \
 630         memcpy(_swap_buffer, _swap_a_ptr, sizeof(a));           \
 631         memcpy(_swap_a_ptr, _swap_b_ptr, sizeof(a) +            \
 632                BUILD_ASSERT_OR_ZERO(sizeof(a) == sizeof(b)));   \
 633         memcpy(_swap_b_ptr, _swap_buffer, sizeof(a));           \
 634 } while (0)
 635
 636 #if defined(NO_MMAP) || defined(USE_WIN32_MMAP)
 637
 638 #ifndef PROT_READ
 639 #define PROT_READ 1
 640 #define PROT_WRITE 2
 641 #define MAP_PRIVATE 1
 642 #endif
 643
 644 #define mmap git_mmap
 645 #define munmap git_munmap
 646 void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset);
 647 int git_munmap(void *start, size_t length);
 648
 649 #else /* NO_MMAP || USE_WIN32_MMAP */
 650
 651 #include <sys/mman.h>
 652
 653 #endif /* NO_MMAP || USE_WIN32_MMAP */
 654
 655 #ifdef NO_MMAP
 656
 657 /* This value must be multiple of (pagesize * 2) */
 658 #define DEFAULT_PACKED_GIT_WINDOW_SIZE (1 * 1024 * 1024)
 659
 660 #else /* NO_MMAP */
 661
 662 /* This value must be multiple of (pagesize * 2) */
 663 #define DEFAULT_PACKED_GIT_WINDOW_SIZE \
 664         (sizeof(void*) >= 8 \
 665                 ?  1 * 1024 * 1024 * 1024 \
 666                 : 32 * 1024 * 1024)
 667
 668 #endif /* NO_MMAP */
 669
 670 #ifndef MAP_FAILED
 671 #define MAP_FAILED ((void *)-1)
 672 #endif
 673
 674 #ifdef NO_ST_BLOCKS_IN_STRUCT_STAT
 675 #define on_disk_bytes(st) ((st).st_size)
 676 #else
 677 #define on_disk_bytes(st) ((st).st_blocks * 512)
 678 #endif
 679
 680 #ifdef NEEDS_MODE_TRANSLATION
 681 #undef S_IFMT
 682 #undef S_IFREG
 683 #undef S_IFDIR
 684 #undef S_IFLNK
 685 #undef S_IFBLK
 686 #undef S_IFCHR
 687 #undef S_IFIFO
 688 #undef S_IFSOCK
 689 #define S_IFMT   0170000
 690 #define S_IFREG  0100000
 691 #define S_IFDIR  0040000
 692 #define S_IFLNK  0120000
 693 #define S_IFBLK  0060000
 694 #define S_IFCHR  0020000
 695 #define S_IFIFO  0010000
 696 #define S_IFSOCK 0140000
 697 #ifdef stat
 698 #undef stat
 699 #endif
 700 #define stat(path, buf) git_stat(path, buf)
 701 int git_stat(const char *, struct stat *);
 702 #ifdef fstat
 703 #undef fstat
 704 #endif
 705 #define fstat(fd, buf) git_fstat(fd, buf)
 706 int git_fstat(int, struct stat *);
 707 #ifdef lstat
 708 #undef lstat
 709 #endif
 710 #define lstat(path, buf) git_lstat(path, buf)
 711 int git_lstat(const char *, struct stat *);
 712 #endif
 713
 714 #define DEFAULT_PACKED_GIT_LIMIT \
 715         ((1024L * 1024L) * (size_t)(sizeof(void*) >= 8 ? (32 * 1024L * 1024L) : 256))
 716
 717 #ifdef NO_PREAD
 718 #define pread git_pread
 719 ssize_t git_pread(int fd, void *buf, size_t count, off_t offset);
 720 #endif
 721 /*
 722  * Forward decl that will remind us if its twin in cache.h changes.
 723  * This function is used in compat/pread.c.  But we can't include
 724  * cache.h there.
 725  */
 726 ssize_t read_in_full(int fd, void *buf, size_t count);
 727
 728 #ifdef NO_SETENV
 729 #define setenv gitsetenv
 730 int gitsetenv(const char *, const char *, int);
 731 #endif
 732
 733 #ifdef NO_MKDTEMP
 734 #define mkdtemp gitmkdtemp
 735 char *gitmkdtemp(char *);
 736 #endif
 737
 738 #ifdef NO_UNSETENV
 739 #define unsetenv gitunsetenv
 740 int gitunsetenv(const char *);
 741 #endif
 742
 743 #ifdef NO_STRCASESTR
 744 #define strcasestr gitstrcasestr
 745 char *gitstrcasestr(const char *haystack, const char *needle);
 746 #endif
 747
 748 #ifdef NO_STRLCPY
 749 #define strlcpy gitstrlcpy
 750 size_t gitstrlcpy(char *, const char *, size_t);
 751 #endif
 752
 753 #ifdef NO_STRTOUMAX
 754 #define strtoumax gitstrtoumax
 755 uintmax_t gitstrtoumax(const char *, char **, int);
 756 #define strtoimax gitstrtoimax
 757 intmax_t gitstrtoimax(const char *, char **, int);
 758 #endif
 759
 760 #ifdef NO_HSTRERROR
 761 #define hstrerror githstrerror
 762 const char *githstrerror(int herror);
 763 #endif
 764
 765 #ifdef NO_MEMMEM
 766 #define memmem gitmemmem
 767 void *gitmemmem(const void *haystack, size_t haystacklen,
 768                 const void *needle, size_t needlelen);
 769 #endif
 770
 771 #ifdef OVERRIDE_STRDUP
 772 #ifdef strdup
 773 #undef strdup
 774 #endif
 775 #define strdup gitstrdup
 776 char *gitstrdup(const char *s);
 777 #endif
 778
 779 #ifdef NO_GETPAGESIZE
 780 #define getpagesize() sysconf(_SC_PAGESIZE)
 781 #endif
 782
 783 #ifndef O_CLOEXEC
 784 #define O_CLOEXEC 0
 785 #endif
 786
 787 #ifdef FREAD_READS_DIRECTORIES
 788 # if !defined(SUPPRESS_FOPEN_REDEFINITION)
 789 #  ifdef fopen
 790 #   undef fopen
 791 #  endif
 792 #  define fopen(a,b) git_fopen(a,b)
 793 # endif
 794 FILE *git_fopen(const char*, const char*);
 795 #endif
 796
 797 #ifdef SNPRINTF_RETURNS_BOGUS
 798 #ifdef snprintf
 799 #undef snprintf
 800 #endif
 801 #define snprintf git_snprintf
 802 int git_snprintf(char *str, size_t maxsize,
 803                  const char *format, ...);
 804 #ifdef vsnprintf
 805 #undef vsnprintf
 806 #endif
 807 #define vsnprintf git_vsnprintf
 808 int git_vsnprintf(char *str, size_t maxsize,
 809                   const char *format, va_list ap);
 810 #endif
 811
 812 #ifdef OPEN_RETURNS_EINTR
 813 #undef open
 814 #define open git_open_with_retry
 815 int git_open_with_retry(const char *path, int flag, ...);
 816 #endif
 817
 818 #ifdef __GLIBC_PREREQ
 819 #if __GLIBC_PREREQ(2, 1)
 820 #define HAVE_STRCHRNUL
 821 #endif
 822 #endif
 823
 824 #ifndef HAVE_STRCHRNUL
 825 #define strchrnul gitstrchrnul
 826 static inline char *gitstrchrnul(const char *s, int c)
 827 {
 828         while (*s && *s != c)
 829                 s++;
 830         return (char *)s;
 831 }
 832 #endif
 833
 834 #ifdef NO_INET_PTON
 835 int inet_pton(int af, const char *src, void *dst);
 836 #endif
 837
 838 #ifdef NO_INET_NTOP
 839 const char *inet_ntop(int af, const void *src, char *dst, size_t size);
 840 #endif
 841
 842 #ifdef NO_PTHREADS
 843 #define atexit git_atexit
 844 int git_atexit(void (*handler)(void));
 845 #endif
 846
 847 static inline size_t st_add(size_t a, size_t b)
 848 {
 849         if (unsigned_add_overflows(a, b))
 850                 die("size_t overflow: %"PRIuMAX" + %"PRIuMAX,
 851                     (uintmax_t)a, (uintmax_t)b);
 852         return a + b;
 853 }
 854 #define st_add3(a,b,c)   st_add(st_add((a),(b)),(c))
 855 #define st_add4(a,b,c,d) st_add(st_add3((a),(b),(c)),(d))
 856
 857 static inline size_t st_mult(size_t a, size_t b)
 858 {
 859         if (unsigned_mult_overflows(a, b))
 860                 die("size_t overflow: %"PRIuMAX" * %"PRIuMAX,
 861                     (uintmax_t)a, (uintmax_t)b);
 862         return a * b;
 863 }
 864
 865 static inline size_t st_sub(size_t a, size_t b)
 866 {
 867         if (a < b)
 868                 die("size_t underflow: %"PRIuMAX" - %"PRIuMAX,
 869                     (uintmax_t)a, (uintmax_t)b);
 870         return a - b;
 871 }
 872
 873 static inline size_t st_left_shift(size_t a, unsigned shift)
 874 {
 875         if (unsigned_left_shift_overflows(a, shift))
 876                 die("size_t overflow: %"PRIuMAX" << %u",
 877                     (uintmax_t)a, shift);
 878         return a << shift;
 879 }
 880
 881 static inline unsigned long cast_size_t_to_ulong(size_t a)
 882 {
 883         if (a != (unsigned long)a)
 884                 die("object too large to read on this platform: %"
 885                     PRIuMAX" is cut off to %lu",
 886                     (uintmax_t)a, (unsigned long)a);
 887         return (unsigned long)a;
 888 }
 889
 890 #ifdef HAVE_ALLOCA_H
 891 # include <alloca.h>
 892 # define xalloca(size)      (alloca(size))
 893 # define xalloca_free(p)    do {} while (0)
 894 #else
 895 # define xalloca(size)      (xmalloc(size))
 896 # define xalloca_free(p)    (free(p))
 897 #endif
 898 char *xstrdup(const char *str);
 899 void *xmalloc(size_t size);
 900 void *xmallocz(size_t size);
 901 void *xmallocz_gently(size_t size);
 902 void *xmemdupz(const void *data, size_t len);
 903 char *xstrndup(const char *str, size_t len);
 904 void *xrealloc(void *ptr, size_t size);
 905 void *xcalloc(size_t nmemb, size_t size);
 906 void xsetenv(const char *name, const char *value, int overwrite);
 907 void *xmmap(void *start, size_t length, int prot, int flags, int fd, off_t offset);
 908 const char *mmap_os_err(void);
 909 void *xmmap_gently(void *start, size_t length, int prot, int flags, int fd, off_t offset);
 910 int xopen(const char *path, int flags, ...);
 911 ssize_t xread(int fd, void *buf, size_t len);
 912 ssize_t xwrite(int fd, const void *buf, size_t len);
 913 ssize_t xpread(int fd, void *buf, size_t len, off_t offset);
 914 int xdup(int fd);
 915 FILE *xfopen(const char *path, const char *mode);
 916 FILE *xfdopen(int fd, const char *mode);
 917 int xmkstemp(char *temp_filename);
 918 int xmkstemp_mode(char *temp_filename, int mode);
 919 char *xgetcwd(void);
 920 FILE *fopen_for_writing(const char *path);
 921 FILE *fopen_or_warn(const char *path, const char *mode);
 922
 923 /*
 924  * Like strncmp, but only return zero if s is NUL-terminated and exactly len
 925  * characters long.  If it is not, consider it greater than t.
 926  */
 927 int xstrncmpz(const char *s, const char *t, size_t len);
 928
 929 /*
 930  * FREE_AND_NULL(ptr) is like free(ptr) followed by ptr = NULL. Note
 931  * that ptr is used twice, so don't pass e.g. ptr++.
 932  */
 933 #define FREE_AND_NULL(p) do { free(p); (p) = NULL; } while (0)
 934
 935 #define ALLOC_ARRAY(x, alloc) (x) = xmalloc(st_mult(sizeof(*(x)), (alloc)))
 936 #define CALLOC_ARRAY(x, alloc) (x) = xcalloc((alloc), sizeof(*(x)))
 937 #define REALLOC_ARRAY(x, alloc) (x) = xrealloc((x), st_mult(sizeof(*(x)), (alloc)))
 938
 939 #define COPY_ARRAY(dst, src, n) copy_array((dst), (src), (n), sizeof(*(dst)) + \
 940         BUILD_ASSERT_OR_ZERO(sizeof(*(dst)) == sizeof(*(src))))
 941 static inline void copy_array(void *dst, const void *src, size_t n, size_t size)
 942 {
 943         if (n)
 944                 memcpy(dst, src, st_mult(size, n));
 945 }
 946
 947 #define MOVE_ARRAY(dst, src, n) move_array((dst), (src), (n), sizeof(*(dst)) + \
 948         BUILD_ASSERT_OR_ZERO(sizeof(*(dst)) == sizeof(*(src))))
 949 static inline void move_array(void *dst, const void *src, size_t n, size_t size)
 950 {
 951         if (n)
 952                 memmove(dst, src, st_mult(size, n));
 953 }
 954
 955 /*
 956  * These functions help you allocate structs with flex arrays, and copy
 957  * the data directly into the array. For example, if you had:
 958  *
 959  *   struct foo {
 960  *     int bar;
 961  *     char name[FLEX_ARRAY];
 962  *   };
 963  *
 964  * you can do:
 965  *
 966  *   struct foo *f;
 967  *   FLEX_ALLOC_MEM(f, name, src, len);
 968  *
 969  * to allocate a "foo" with the contents of "src" in the "name" field.
 970  * The resulting struct is automatically zero'd, and the flex-array field
 971  * is NUL-terminated (whether the incoming src buffer was or not).
 972  *
 973  * The FLEXPTR_* variants operate on structs that don't use flex-arrays,
 974  * but do want to store a pointer to some extra data in the same allocated
 975  * block. For example, if you have:
 976  *
 977  *   struct foo {
 978  *     char *name;
 979  *     int bar;
 980  *   };
 981  *
 982  * you can do:
 983  *
 984  *   struct foo *f;
 985  *   FLEXPTR_ALLOC_STR(f, name, src);
 986  *
 987  * and "name" will point to a block of memory after the struct, which will be
 988  * freed along with the struct (but the pointer can be repointed anywhere).
 989  *
 990  * The *_STR variants accept a string parameter rather than a ptr/len
 991  * combination.
 992  *
 993  * Note that these macros will evaluate the first parameter multiple
 994  * times, and it must be assignable as an lvalue.
 995  */
 996 #define FLEX_ALLOC_MEM(x, flexname, buf, len) do { \
 997         size_t flex_array_len_ = (len); \
 998         (x) = xcalloc(1, st_add3(sizeof(*(x)), flex_array_len_, 1)); \
 999         memcpy((void *)(x)->flexname, (buf), flex_array_len_); \
1000 } while (0)
1001 #define FLEXPTR_ALLOC_MEM(x, ptrname, buf, len) do { \
1002         size_t flex_array_len_ = (len); \
1003         (x) = xcalloc(1, st_add3(sizeof(*(x)), flex_array_len_, 1)); \
1004         memcpy((x) + 1, (buf), flex_array_len_); \
1005         (x)->ptrname = (void *)((x)+1); \
1006 } while(0)
1007 #define FLEX_ALLOC_STR(x, flexname, str) \
1008         FLEX_ALLOC_MEM((x), flexname, (str), strlen(str))
1009 #define FLEXPTR_ALLOC_STR(x, ptrname, str) \
1010         FLEXPTR_ALLOC_MEM((x), ptrname, (str), strlen(str))
1011
1012 static inline char *xstrdup_or_null(const char *str)
1013 {
1014         return str ? xstrdup(str) : NULL;
1015 }
1016
1017 static inline size_t xsize_t(off_t len)
1018 {
1019         if (len < 0 || (uintmax_t) len > SIZE_MAX)
1020                 die("Cannot handle files this big");
1021         return (size_t) len;
1022 }
1023
1024 __attribute__((format (printf, 3, 4)))
1025 int xsnprintf(char *dst, size_t max, const char *fmt, ...);
1026
1027 #ifndef HOST_NAME_MAX
1028 #define HOST_NAME_MAX 256
1029 #endif
1030
1031 int xgethostname(char *buf, size_t len);
1032
1033 /* in ctype.c, for kwset users */
1034 extern const unsigned char tolower_trans_tbl[256];
1035
1036 /* Sane ctype - no locale, and works with signed chars */
1037 #undef isascii
1038 #undef isspace
1039 #undef isdigit
1040 #undef isalpha
1041 #undef isalnum
1042 #undef isprint
1043 #undef islower
1044 #undef isupper
1045 #undef tolower
1046 #undef toupper
1047 #undef iscntrl
1048 #undef ispunct
1049 #undef isxdigit
1050
1051 extern const unsigned char sane_ctype[256];
1052 #define GIT_SPACE 0x01
1053 #define GIT_DIGIT 0x02
1054 #define GIT_ALPHA 0x04
1055 #define GIT_GLOB_SPECIAL 0x08
1056 #define GIT_REGEX_SPECIAL 0x10
1057 #define GIT_PATHSPEC_MAGIC 0x20
1058 #define GIT_CNTRL 0x40
1059 #define GIT_PUNCT 0x80
1060 #define sane_istest(x,mask) ((sane_ctype[(unsigned char)(x)] & (mask)) != 0)
1061 #define isascii(x) (((x) & ~0x7f) == 0)
1062 #define isspace(x) sane_istest(x,GIT_SPACE)
1063 #define isdigit(x) sane_istest(x,GIT_DIGIT)
1064 #define isalpha(x) sane_istest(x,GIT_ALPHA)
1065 #define isalnum(x) sane_istest(x,GIT_ALPHA | GIT_DIGIT)
1066 #define isprint(x) ((x) >= 0x20 && (x) <= 0x7e)
1067 #define islower(x) sane_iscase(x, 1)
1068 #define isupper(x) sane_iscase(x, 0)
1069 #define is_glob_special(x) sane_istest(x,GIT_GLOB_SPECIAL)
1070 #define is_regex_special(x) sane_istest(x,GIT_GLOB_SPECIAL | GIT_REGEX_SPECIAL)
1071 #define iscntrl(x) (sane_istest(x,GIT_CNTRL))
1072 #define ispunct(x) sane_istest(x, GIT_PUNCT | GIT_REGEX_SPECIAL | \
1073                 GIT_GLOB_SPECIAL | GIT_PATHSPEC_MAGIC)
1074 #define isxdigit(x) (hexval_table[(unsigned char)(x)] != -1)
1075 #define tolower(x) sane_case((unsigned char)(x), 0x20)
1076 #define toupper(x) sane_case((unsigned char)(x), 0)
1077 #define is_pathspec_magic(x) sane_istest(x,GIT_PATHSPEC_MAGIC)
1078
1079 static inline int sane_case(int x, int high)
1080 {
1081         if (sane_istest(x, GIT_ALPHA))
1082                 x = (x & ~0x20) | high;
1083         return x;
1084 }
1085
1086 static inline int sane_iscase(int x, int is_lower)
1087 {
1088         if (!sane_istest(x, GIT_ALPHA))
1089                 return 0;
1090
1091         if (is_lower)
1092                 return (x & 0x20) != 0;
1093         else
1094                 return (x & 0x20) == 0;
1095 }
1096
1097 /*
1098  * Like skip_prefix, but compare case-insensitively. Note that the comparison
1099  * is done via tolower(), so it is strictly ASCII (no multi-byte characters or
1100  * locale-specific conversions).
1101  */
1102 static inline int skip_iprefix(const char *str, const char *prefix,
1103                                const char **out)
1104 {
1105         do {
1106                 if (!*prefix) {
1107                         *out = str;
1108                         return 1;
1109                 }
1110         } while (tolower(*str++) == tolower(*prefix++));
1111         return 0;
1112 }
1113
1114 static inline int strtoul_ui(char const *s, int base, unsigned int *result)
1115 {
1116         unsigned long ul;
1117         char *p;
1118
1119         errno = 0;
1120         /* negative values would be accepted by strtoul */
1121         if (strchr(s, '-'))
1122                 return -1;
1123         ul = strtoul(s, &p, base);
1124         if (errno || *p || p == s || (unsigned int) ul != ul)
1125                 return -1;
1126         *result = ul;
1127         return 0;
1128 }
1129
1130 static inline int strtol_i(char const *s, int base, int *result)
1131 {
1132         long ul;
1133         char *p;
1134
1135         errno = 0;
1136         ul = strtol(s, &p, base);
1137         if (errno || *p || p == s || (int) ul != ul)
1138                 return -1;
1139         *result = ul;
1140         return 0;
1141 }
1142
1143 void git_stable_qsort(void *base, size_t nmemb, size_t size,
1144                       int(*compar)(const void *, const void *));
1145 #ifdef INTERNAL_QSORT
1146 #define qsort git_stable_qsort
1147 #endif
1148
1149 #define QSORT(base, n, compar) sane_qsort((base), (n), sizeof(*(base)), compar)
1150 static inline void sane_qsort(void *base, size_t nmemb, size_t size,
1151                               int(*compar)(const void *, const void *))
1152 {
1153         if (nmemb > 1)
1154                 qsort(base, nmemb, size, compar);
1155 }
1156
1157 #define STABLE_QSORT(base, n, compar) \
1158         git_stable_qsort((base), (n), sizeof(*(base)), compar)
1159
1160 #ifndef HAVE_ISO_QSORT_S
1161 int git_qsort_s(void *base, size_t nmemb, size_t size,
1162                 int (*compar)(const void *, const void *, void *), void *ctx);
1163 #define qsort_s git_qsort_s
1164 #endif
1165
1166 #define QSORT_S(base, n, compar, ctx) do {                      \
1167         if (qsort_s((base), (n), sizeof(*(base)), compar, ctx)) \
1168                 BUG("qsort_s() failed");                        \
1169 } while (0)
1170
1171 #ifndef REG_STARTEND
1172 #error "Git requires REG_STARTEND support. Compile with NO_REGEX=NeedsStartEnd"
1173 #endif
1174
1175 static inline int regexec_buf(const regex_t *preg, const char *buf, size_t size,
1176                               size_t nmatch, regmatch_t pmatch[], int eflags)
1177 {
1178         assert(nmatch > 0 && pmatch);
1179         pmatch[0].rm_so = 0;
1180         pmatch[0].rm_eo = size;
1181         return regexec(preg, buf, nmatch, pmatch, eflags | REG_STARTEND);
1182 }
1183
1184 #ifndef DIR_HAS_BSD_GROUP_SEMANTICS
1185 # define FORCE_DIR_SET_GID S_ISGID
1186 #else
1187 # define FORCE_DIR_SET_GID 0
1188 #endif
1189
1190 #ifdef NO_NSEC
1191 #undef USE_NSEC
1192 #define ST_CTIME_NSEC(st) 0
1193 #define ST_MTIME_NSEC(st) 0
1194 #else
1195 #ifdef USE_ST_TIMESPEC
1196 #define ST_CTIME_NSEC(st) ((unsigned int)((st).st_ctimespec.tv_nsec))
1197 #define ST_MTIME_NSEC(st) ((unsigned int)((st).st_mtimespec.tv_nsec))
1198 #else
1199 #define ST_CTIME_NSEC(st) ((unsigned int)((st).st_ctim.tv_nsec))
1200 #define ST_MTIME_NSEC(st) ((unsigned int)((st).st_mtim.tv_nsec))
1201 #endif
1202 #endif
1203
1204 #ifdef UNRELIABLE_FSTAT
1205 #define fstat_is_reliable() 0
1206 #else
1207 #define fstat_is_reliable() 1
1208 #endif
1209
1210 #ifndef va_copy
1211 /*
1212  * Since an obvious implementation of va_list would be to make it a
1213  * pointer into the stack frame, a simple assignment will work on
1214  * many systems.  But let's try to be more portable.
1215  */
1216 #ifdef __va_copy
1217 #define va_copy(dst, src) __va_copy(dst, src)
1218 #else
1219 #define va_copy(dst, src) ((dst) = (src))
1220 #endif
1221 #endif
1222
1223 /*
1224  * This is always defined as a first step towards making the use of variadic
1225  * macros unconditional. If it causes compilation problems on your platform,
1226  * please report it to the Git mailing list at git@vger.kernel.org.
1227  */
1228 #define HAVE_VARIADIC_MACROS 1
1229
1230 /* usage.c: only to be used for testing BUG() implementation (see test-tool) */
1231 extern int BUG_exit_code;
1232
1233 #ifdef HAVE_VARIADIC_MACROS
1234 __attribute__((format (printf, 3, 4))) NORETURN
1235 void BUG_fl(const char *file, int line, const char *fmt, ...);
1236 #define BUG(...) BUG_fl(__FILE__, __LINE__, __VA_ARGS__)
1237 #else
1238 __attribute__((format (printf, 1, 2))) NORETURN
1239 void BUG(const char *fmt, ...);
1240 #endif
1241
1242 /*
1243  * Preserves errno, prints a message, but gives no warning for ENOENT.
1244  * Returns 0 on success, which includes trying to unlink an object that does
1245  * not exist.
1246  */
1247 int unlink_or_warn(const char *path);
1248  /*
1249   * Tries to unlink file.  Returns 0 if unlink succeeded
1250   * or the file already didn't exist.  Returns -1 and
1251   * appends a message to err suitable for
1252   * 'error("%s", err->buf)' on error.
1253   */
1254 int unlink_or_msg(const char *file, struct strbuf *err);
1255 /*
1256  * Preserves errno, prints a message, but gives no warning for ENOENT.
1257  * Returns 0 on success, which includes trying to remove a directory that does
1258  * not exist.
1259  */
1260 int rmdir_or_warn(const char *path);
1261 /*
1262  * Calls the correct function out of {unlink,rmdir}_or_warn based on
1263  * the supplied file mode.
1264  */
1265 int remove_or_warn(unsigned int mode, const char *path);
1266
1267 /*
1268  * Call access(2), but warn for any error except "missing file"
1269  * (ENOENT or ENOTDIR).
1270  */
1271 #define ACCESS_EACCES_OK (1U << 0)
1272 int access_or_warn(const char *path, int mode, unsigned flag);
1273 int access_or_die(const char *path, int mode, unsigned flag);
1274
1275 /* Warn on an inaccessible file if errno indicates this is an error */
1276 int warn_on_fopen_errors(const char *path);
1277
1278 /*
1279  * Open with O_NOFOLLOW, or equivalent. Note that the fallback equivalent
1280  * may be racy. Do not use this as protection against an attacker who can
1281  * simultaneously create paths.
1282  */
1283 int open_nofollow(const char *path, int flags);
1284
1285 #ifndef SHELL_PATH
1286 # define SHELL_PATH "/bin/sh"
1287 #endif
1288
1289 #ifndef _POSIX_THREAD_SAFE_FUNCTIONS
1290 static inline void flockfile(FILE *fh)
1291 {
1292         ; /* nothing */
1293 }
1294 static inline void funlockfile(FILE *fh)
1295 {
1296         ; /* nothing */
1297 }
1298 #define getc_unlocked(fh) getc(fh)
1299 #endif
1300
1301 #ifdef FILENO_IS_A_MACRO
1302 int git_fileno(FILE *stream);
1303 # ifndef COMPAT_CODE_FILENO
1304 #  undef fileno
1305 #  define fileno(p) git_fileno(p)
1306 # endif
1307 #endif
1308
1309 #ifdef NEED_ACCESS_ROOT_HANDLER
1310 int git_access(const char *path, int mode);
1311 # ifndef COMPAT_CODE_ACCESS
1312 #  ifdef access
1313 #  undef access
1314 #  endif
1315 #  define access(path, mode) git_access(path, mode)
1316 # endif
1317 #endif
1318
1319 /*
1320  * Our code often opens a path to an optional file, to work on its
1321  * contents when we can successfully open it.  We can ignore a failure
1322  * to open if such an optional file does not exist, but we do want to
1323  * report a failure in opening for other reasons (e.g. we got an I/O
1324  * error, or the file is there, but we lack the permission to open).
1325  *
1326  * Call this function after seeing an error from open() or fopen() to
1327  * see if the errno indicates a missing file that we can safely ignore.
1328  */
1329 static inline int is_missing_file_error(int errno_)
1330 {
1331         return (errno_ == ENOENT || errno_ == ENOTDIR);
1332 }
1333
1334 int cmd_main(int, const char **);
1335
1336 /*
1337  * Intercept all calls to exit() and route them to trace2 to
1338  * optionally emit a message before calling the real exit().
1339  */
1340 int trace2_cmd_exit_fl(const char *file, int line, int code);
1341 #define exit(code) exit(trace2_cmd_exit_fl(__FILE__, __LINE__, (code)))
1342
1343 /*
1344  * You can mark a stack variable with UNLEAK(var) to avoid it being
1345  * reported as a leak by tools like LSAN or valgrind. The argument
1346  * should generally be the variable itself (not its address and not what
1347  * it points to). It's safe to use this on pointers which may already
1348  * have been freed, or on pointers which may still be in use.
1349  *
1350  * Use this _only_ for a variable that leaks by going out of scope at
1351  * program exit (so only from cmd_* functions or their direct helpers).
1352  * Normal functions, especially those which may be called multiple
1353  * times, should actually free their memory. This is only meant as
1354  * an annotation, and does nothing in non-leak-checking builds.
1355  */
1356 #ifdef SUPPRESS_ANNOTATED_LEAKS
1357 void unleak_memory(const void *ptr, size_t len);
1358 #define UNLEAK(var) unleak_memory(&(var), sizeof(var))
1359 #else
1360 #define UNLEAK(var) do {} while (0)
1361 #endif
1362
1363 /*
1364  * This include must come after system headers, since it introduces macros that
1365  * replace system names.
1366  */
1367 #include "banned.h"
1368
1369 /*
1370  * container_of - Get the address of an object containing a field.
1371  *
1372  * @ptr: pointer to the field.
1373  * @type: type of the object.
1374  * @member: name of the field within the object.
1375  */
1376 #define container_of(ptr, type, member) \
1377         ((type *) ((char *)(ptr) - offsetof(type, member)))
1378
1379 /*
1380  * helper function for `container_of_or_null' to avoid multiple
1381  * evaluation of @ptr
1382  */
1383 static inline void *container_of_or_null_offset(void *ptr, size_t offset)
1384 {
1385         return ptr ? (char *)ptr - offset : NULL;
1386 }
1387
1388 /*
1389  * like `container_of', but allows returned value to be NULL
1390  */
1391 #define container_of_or_null(ptr, type, member) \
1392         (type *)container_of_or_null_offset(ptr, offsetof(type, member))
1393
1394 /*
1395  * like offsetof(), but takes a pointer to a variable of type which
1396  * contains @member, instead of a specified type.
1397  * @ptr is subject to multiple evaluation since we can't rely on __typeof__
1398  * everywhere.
1399  */
1400 #if defined(__GNUC__) /* clang sets this, too */
1401 #define OFFSETOF_VAR(ptr, member) offsetof(__typeof__(*ptr), member)
1402 #else /* !__GNUC__ */
1403 #define OFFSETOF_VAR(ptr, member) \
1404         ((uintptr_t)&(ptr)->member - (uintptr_t)(ptr))
1405 #endif /* !__GNUC__ */
1406
1407 void sleep_millisec(int millisec);
1408
1409 #endif