git-compat-util.h

   1 #ifndef GIT_COMPAT_UTIL_H
   2 #define GIT_COMPAT_UTIL_H
   3
   4 #if __STDC_VERSION__ - 0 < 199901L
   5 /*
   6  * Git is in a testing period for mandatory C99 support in the compiler.  If
   7  * your compiler is reasonably recent, you can try to enable C99 support (or,
   8  * for MSVC, C11 support).  If you encounter a problem and can't enable C99
   9  * support with your compiler (such as with "-std=gnu99") and don't have access
  10  * to one with this support, such as GCC or Clang, you can remove this #if
  11  * directive, but please report the details of your system to
  12  * git@vger.kernel.org.
  13  */
  14 #error "Required C99 support is in a test phase.  Please see git-compat-util.h for more details."
  15 #endif
  16
  17 #ifdef USE_MSVC_CRTDBG
  18 /*
  19  * For these to work they must appear very early in each
  20  * file -- before most of the standard header files.
  21  */
  22 #include <stdlib.h>
  23 #include <crtdbg.h>
  24 #endif
  25
  26 struct strbuf;
  27
  28
  29 #define _FILE_OFFSET_BITS 64
  30
  31
  32 /* Derived from Linux "Features Test Macro" header
  33  * Convenience macros to test the versions of gcc (or
  34  * a compatible compiler).
  35  * Use them like this:
  36  *  #if GIT_GNUC_PREREQ (2,8)
  37  *   ... code requiring gcc 2.8 or later ...
  38  *  #endif
  39 */
  40 #if defined(__GNUC__) && defined(__GNUC_MINOR__)
  41 # define GIT_GNUC_PREREQ(maj, min) \
  42         ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
  43 #else
  44  #define GIT_GNUC_PREREQ(maj, min) 0
  45 #endif
  46
  47
  48 #ifndef FLEX_ARRAY
  49 /*
  50  * See if our compiler is known to support flexible array members.
  51  */
  52
  53 /*
  54  * Check vendor specific quirks first, before checking the
  55  * __STDC_VERSION__, as vendor compilers can lie and we need to be
  56  * able to work them around.  Note that by not defining FLEX_ARRAY
  57  * here, we can fall back to use the "safer but a bit wasteful" one
  58  * later.
  59  */
  60 #if defined(__SUNPRO_C) && (__SUNPRO_C <= 0x580)
  61 #elif defined(__GNUC__)
  62 # if (__GNUC__ >= 3)
  63 #  define FLEX_ARRAY /* empty */
  64 # else
  65 #  define FLEX_ARRAY 0 /* older GNU extension */
  66 # endif
  67 #elif defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)
  68 # define FLEX_ARRAY /* empty */
  69 #endif
  70
  71 /*
  72  * Otherwise, default to safer but a bit wasteful traditional style
  73  */
  74 #ifndef FLEX_ARRAY
  75 # define FLEX_ARRAY 1
  76 #endif
  77 #endif
  78
  79
  80 /*
  81  * BUILD_ASSERT_OR_ZERO - assert a build-time dependency, as an expression.
  82  * @cond: the compile-time condition which must be true.
  83  *
  84  * Your compile will fail if the condition isn't true, or can't be evaluated
  85  * by the compiler.  This can be used in an expression: its value is "0".
  86  *
  87  * Example:
  88  *      #define foo_to_char(foo)                                        \
  89  *               ((char *)(foo)                                         \
  90  *                + BUILD_ASSERT_OR_ZERO(offsetof(struct foo, string) == 0))
  91  */
  92 #define BUILD_ASSERT_OR_ZERO(cond) \
  93         (sizeof(char [1 - 2*!(cond)]) - 1)
  94
  95 #if GIT_GNUC_PREREQ(3, 1)
  96  /* &arr[0] degrades to a pointer: a different type from an array */
  97 # define BARF_UNLESS_AN_ARRAY(arr)                                              \
  98         BUILD_ASSERT_OR_ZERO(!__builtin_types_compatible_p(__typeof__(arr), \
  99                                                            __typeof__(&(arr)[0])))
 100 # define BARF_UNLESS_COPYABLE(dst, src) \
 101         BUILD_ASSERT_OR_ZERO(__builtin_types_compatible_p(__typeof__(*(dst)), \
 102                                                           __typeof__(*(src))))
 103 #else
 104 # define BARF_UNLESS_AN_ARRAY(arr) 0
 105 # define BARF_UNLESS_COPYABLE(dst, src) \
 106         BUILD_ASSERT_OR_ZERO(0 ? ((*(dst) = *(src)), 0) : \
 107                                  sizeof(*(dst)) == sizeof(*(src)))
 108 #endif
 109 /*
 110  * ARRAY_SIZE - get the number of elements in a visible array
 111  * @x: the array whose size you want.
 112  *
 113  * This does not work on pointers, or arrays declared as [], or
 114  * function parameters.  With correct compiler support, such usage
 115  * will cause a build error (see the build_assert_or_zero macro).
 116  */
 117 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]) + BARF_UNLESS_AN_ARRAY(x))
 118
 119 #define bitsizeof(x)  (CHAR_BIT * sizeof(x))
 120
 121 #define maximum_signed_value_of_type(a) \
 122     (INTMAX_MAX >> (bitsizeof(intmax_t) - bitsizeof(a)))
 123
 124 #define maximum_unsigned_value_of_type(a) \
 125     (UINTMAX_MAX >> (bitsizeof(uintmax_t) - bitsizeof(a)))
 126
 127 /*
 128  * Signed integer overflow is undefined in C, so here's a helper macro
 129  * to detect if the sum of two integers will overflow.
 130  *
 131  * Requires: a >= 0, typeof(a) equals typeof(b)
 132  */
 133 #define signed_add_overflows(a, b) \
 134     ((b) > maximum_signed_value_of_type(a) - (a))
 135
 136 #define unsigned_add_overflows(a, b) \
 137     ((b) > maximum_unsigned_value_of_type(a) - (a))
 138
 139 /*
 140  * Returns true if the multiplication of "a" and "b" will
 141  * overflow. The types of "a" and "b" must match and must be unsigned.
 142  * Note that this macro evaluates "a" twice!
 143  */
 144 #define unsigned_mult_overflows(a, b) \
 145     ((a) && (b) > maximum_unsigned_value_of_type(a) / (a))
 146
 147 /*
 148  * Returns true if the left shift of "a" by "shift" bits will
 149  * overflow. The type of "a" must be unsigned.
 150  */
 151 #define unsigned_left_shift_overflows(a, shift) \
 152     ((shift) < bitsizeof(a) && \
 153      (a) > maximum_unsigned_value_of_type(a) >> (shift))
 154
 155 #ifdef __GNUC__
 156 #define TYPEOF(x) (__typeof__(x))
 157 #else
 158 #define TYPEOF(x)
 159 #endif
 160
 161 #define MSB(x, bits) ((x) & TYPEOF(x)(~0ULL << (bitsizeof(x) - (bits))))
 162 #define HAS_MULTI_BITS(i)  ((i) & ((i) - 1))  /* checks if an integer has more than 1 bit set */
 163
 164 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
 165
 166 /* Approximation of the length of the decimal representation of this type. */
 167 #define decimal_length(x)       ((int)(sizeof(x) * 2.56 + 0.5) + 1)
 168
 169 #ifdef __MINGW64__
 170 #define _POSIX_C_SOURCE 1
 171 #elif defined(__sun__)
 172  /*
 173   * On Solaris, when _XOPEN_EXTENDED is set, its header file
 174   * forces the programs to be XPG4v2, defeating any _XOPEN_SOURCE
 175   * setting to say we are XPG5 or XPG6.  Also on Solaris,
 176   * XPG6 programs must be compiled with a c99 compiler, while
 177   * non XPG6 programs must be compiled with a pre-c99 compiler.
 178   */
 179 # if __STDC_VERSION__ - 0 >= 199901L
 180 # define _XOPEN_SOURCE 600
 181 # else
 182 # define _XOPEN_SOURCE 500
 183 # endif
 184 #elif !defined(__APPLE__) && !defined(__FreeBSD__) && !defined(__USLC__) && \
 185       !defined(_M_UNIX) && !defined(__sgi) && !defined(__DragonFly__) && \
 186       !defined(__TANDEM) && !defined(__QNX__) && !defined(__MirBSD__) && \
 187       !defined(__CYGWIN__)
 188 #define _XOPEN_SOURCE 600 /* glibc2 and AIX 5.3L need 500, OpenBSD needs 600 for S_ISLNK() */
 189 #define _XOPEN_SOURCE_EXTENDED 1 /* AIX 5.3L needs this */
 190 #endif
 191 #define _ALL_SOURCE 1
 192 #define _GNU_SOURCE 1
 193 #define _BSD_SOURCE 1
 194 #define _DEFAULT_SOURCE 1
 195 #define _NETBSD_SOURCE 1
 196 #define _SGI_SOURCE 1
 197
 198 /*
 199  * UNUSED marks a function parameter that is always unused.  It also
 200  * can be used to annotate a function, a variable, or a type that is
 201  * always unused.
 202  *
 203  * A callback interface may dictate that a function accepts a
 204  * parameter at that position, but the implementation of the function
 205  * may not need to use the parameter.  In such a case, mark the parameter
 206  * with UNUSED.
 207  *
 208  * When a parameter may be used or unused, depending on conditional
 209  * compilation, consider using MAYBE_UNUSED instead.
 210  */
 211 #if GIT_GNUC_PREREQ(4, 5)
 212 #define UNUSED __attribute__((unused)) \
 213         __attribute__((deprecated ("parameter declared as UNUSED")))
 214 #elif defined(__GNUC__)
 215 #define UNUSED __attribute__((unused)) \
 216         __attribute__((deprecated))
 217 #else
 218 #define UNUSED
 219 #endif
 220
 221 #if defined(WIN32) && !defined(__CYGWIN__) /* Both MinGW and MSVC */
 222 # if !defined(_WIN32_WINNT)
 223 #  define _WIN32_WINNT 0x0600
 224 # endif
 225 #define WIN32_LEAN_AND_MEAN  /* stops windows.h including winsock.h */
 226 #include <winsock2.h>
 227 #ifndef NO_UNIX_SOCKETS
 228 #include <afunix.h>
 229 #endif
 230 #include <windows.h>
 231 #define GIT_WINDOWS_NATIVE
 232 #endif
 233
 234 #if defined(NO_UNIX_SOCKETS) || !defined(GIT_WINDOWS_NATIVE)
 235 static inline int _have_unix_sockets(void)
 236 {
 237 #if defined(NO_UNIX_SOCKETS)
 238         return 0;
 239 #else
 240         return 1;
 241 #endif
 242 }
 243 #define have_unix_sockets _have_unix_sockets
 244 #endif
 245
 246 #include <unistd.h>
 247 #include <stdio.h>
 248 #include <sys/stat.h>
 249 #include <fcntl.h>
 250 #include <stddef.h>
 251 #include <stdlib.h>
 252 #include <stdarg.h>
 253 #include <stdbool.h>
 254 #include <string.h>
 255 #ifdef HAVE_STRINGS_H
 256 #include <strings.h> /* for strcasecmp() */
 257 #endif
 258 #include <errno.h>
 259 #include <limits.h>
 260 #include <locale.h>
 261 #ifdef NEEDS_SYS_PARAM_H
 262 #include <sys/param.h>
 263 #endif
 264 #include <sys/types.h>
 265 #include <dirent.h>
 266 #include <sys/time.h>
 267 #include <time.h>
 268 #include <signal.h>
 269 #include <assert.h>
 270 #include <regex.h>
 271 #include <utime.h>
 272 #include <syslog.h>
 273 #if !defined(NO_POLL_H)
 274 #include <poll.h>
 275 #elif !defined(NO_SYS_POLL_H)
 276 #include <sys/poll.h>
 277 #else
 278 /* Pull the compat stuff */
 279 #include <poll.h>
 280 #endif
 281 #ifdef HAVE_BSD_SYSCTL
 282 #include <sys/sysctl.h>
 283 #endif
 284
 285 /* Used by compat/win32/path-utils.h, and more */
 286 static inline int is_xplatform_dir_sep(int c)
 287 {
 288         return c == '/' || c == '\\';
 289 }
 290
 291 #if defined(__CYGWIN__)
 292 #include "compat/win32/path-utils.h"
 293 #endif
 294 #if defined(__MINGW32__)
 295 /* pull in Windows compatibility stuff */
 296 #include "compat/win32/path-utils.h"
 297 #include "compat/mingw.h"
 298 #elif defined(_MSC_VER)
 299 #include "compat/win32/path-utils.h"
 300 #include "compat/msvc.h"
 301 #else
 302 #include <sys/utsname.h>
 303 #include <sys/wait.h>
 304 #include <sys/resource.h>
 305 #include <sys/socket.h>
 306 #include <sys/ioctl.h>
 307 #include <sys/statvfs.h>
 308 #include <termios.h>
 309 #ifndef NO_SYS_SELECT_H
 310 #include <sys/select.h>
 311 #endif
 312 #include <netinet/in.h>
 313 #include <netinet/tcp.h>
 314 #include <arpa/inet.h>
 315 #include <netdb.h>
 316 #include <pwd.h>
 317 #include <sys/un.h>
 318 #ifndef NO_INTTYPES_H
 319 #include <inttypes.h>
 320 #else
 321 #include <stdint.h>
 322 #endif
 323 #ifdef HAVE_ARC4RANDOM_LIBBSD
 324 #include <bsd/stdlib.h>
 325 #endif
 326 #ifdef HAVE_GETRANDOM
 327 #include <sys/random.h>
 328 #endif
 329 #ifdef NO_INTPTR_T
 330 /*
 331  * On I16LP32, ILP32 and LP64 "long" is the safe bet, however
 332  * on LLP86, IL33LLP64 and P64 it needs to be "long long",
 333  * while on IP16 and IP16L32 it is "int" (resp. "short")
 334  * Size needs to match (or exceed) 'sizeof(void *)'.
 335  * We can't take "long long" here as not everybody has it.
 336  */
 337 typedef long intptr_t;
 338 typedef unsigned long uintptr_t;
 339 #endif
 340 #undef _ALL_SOURCE /* AIX 5.3L defines a struct list with _ALL_SOURCE. */
 341 #include <grp.h>
 342 #define _ALL_SOURCE 1
 343 #endif
 344
 345 /* used on Mac OS X */
 346 #ifdef PRECOMPOSE_UNICODE
 347 #include "compat/precompose_utf8.h"
 348 #else
 349 static inline const char *precompose_argv_prefix(int argc UNUSED,
 350                                                  const char **argv UNUSED,
 351                                                  const char *prefix)
 352 {
 353         return prefix;
 354 }
 355 static inline const char *precompose_string_if_needed(const char *in)
 356 {
 357         return in;
 358 }
 359
 360 #define probe_utf8_pathname_composition()
 361 #endif
 362
 363 #ifdef MKDIR_WO_TRAILING_SLASH
 364 #define mkdir(a,b) compat_mkdir_wo_trailing_slash((a),(b))
 365 int compat_mkdir_wo_trailing_slash(const char*, mode_t);
 366 #endif
 367
 368 #ifdef time
 369 #undef time
 370 #endif
 371 static inline time_t git_time(time_t *tloc)
 372 {
 373         struct timeval tv;
 374
 375         /*
 376          * Avoid time(NULL), which can disagree with gettimeofday(2)
 377          * and filesystem timestamps.
 378          */
 379         gettimeofday(&tv, NULL);
 380
 381         if (tloc)
 382                 *tloc = tv.tv_sec;
 383         return tv.tv_sec;
 384 }
 385 #define time git_time
 386
 387 #ifdef NO_STRUCT_ITIMERVAL
 388 struct itimerval {
 389         struct timeval it_interval;
 390         struct timeval it_value;
 391 };
 392 #endif
 393
 394 #ifdef NO_SETITIMER
 395 static inline int git_setitimer(int which UNUSED,
 396                                 const struct itimerval *value UNUSED,
 397                                 struct itimerval *newvalue UNUSED) {
 398         return 0; /* pretend success */
 399 }
 400 #undef setitimer
 401 #define setitimer(which,value,ovalue) git_setitimer(which,value,ovalue)
 402 #endif
 403
 404 #ifndef NO_LIBGEN_H
 405 #include <libgen.h>
 406 #else
 407 #define basename gitbasename
 408 char *gitbasename(char *);
 409 #define dirname gitdirname
 410 char *gitdirname(char *);
 411 #endif
 412
 413 #ifndef NO_ICONV
 414 #include <iconv.h>
 415 #endif
 416
 417 #ifndef NO_OPENSSL
 418 #ifdef __APPLE__
 419 #undef __AVAILABILITY_MACROS_USES_AVAILABILITY
 420 #define __AVAILABILITY_MACROS_USES_AVAILABILITY 0
 421 #include <AvailabilityMacros.h>
 422 #undef DEPRECATED_ATTRIBUTE
 423 #define DEPRECATED_ATTRIBUTE
 424 #undef __AVAILABILITY_MACROS_USES_AVAILABILITY
 425 #endif
 426 #include <openssl/ssl.h>
 427 #include <openssl/err.h>
 428 #endif
 429
 430 #ifdef HAVE_SYSINFO
 431 # include <sys/sysinfo.h>
 432 #endif
 433
 434 /* On most systems <netdb.h> would have given us this, but
 435  * not on some systems (e.g. z/OS).
 436  */
 437 #ifndef NI_MAXHOST
 438 #define NI_MAXHOST 1025
 439 #endif
 440
 441 #ifndef NI_MAXSERV
 442 #define NI_MAXSERV 32
 443 #endif
 444
 445 /* On most systems <limits.h> would have given us this, but
 446  * not on some systems (e.g. GNU/Hurd).
 447  */
 448 #ifndef PATH_MAX
 449 #define PATH_MAX 4096
 450 #endif
 451
 452 #ifndef NAME_MAX
 453 #define NAME_MAX 255
 454 #endif
 455
 456 typedef uintmax_t timestamp_t;
 457 #define PRItime PRIuMAX
 458 #define parse_timestamp strtoumax
 459 #define TIME_MAX UINTMAX_MAX
 460 #define TIME_MIN 0
 461
 462 #ifndef PATH_SEP
 463 #define PATH_SEP ':'
 464 #endif
 465
 466 #ifdef HAVE_PATHS_H
 467 #include <paths.h>
 468 #endif
 469 #ifndef _PATH_DEFPATH
 470 #define _PATH_DEFPATH "/usr/local/bin:/usr/bin:/bin"
 471 #endif
 472
 473 #ifndef platform_core_config
 474 struct config_context;
 475 static inline int noop_core_config(const char *var UNUSED,
 476                                    const char *value UNUSED,
 477                                    const struct config_context *ctx UNUSED,
 478                                    void *cb UNUSED)
 479 {
 480         return 0;
 481 }
 482 #define platform_core_config noop_core_config
 483 #endif
 484
 485 int lstat_cache_aware_rmdir(const char *path);
 486 #if !defined(__MINGW32__) && !defined(_MSC_VER)
 487 #define rmdir lstat_cache_aware_rmdir
 488 #endif
 489
 490 #ifndef has_dos_drive_prefix
 491 static inline int git_has_dos_drive_prefix(const char *path UNUSED)
 492 {
 493         return 0;
 494 }
 495 #define has_dos_drive_prefix git_has_dos_drive_prefix
 496 #endif
 497
 498 #ifndef skip_dos_drive_prefix
 499 static inline int git_skip_dos_drive_prefix(char **path UNUSED)
 500 {
 501         return 0;
 502 }
 503 #define skip_dos_drive_prefix git_skip_dos_drive_prefix
 504 #endif
 505
 506 static inline int git_is_dir_sep(int c)
 507 {
 508         return c == '/';
 509 }
 510 #ifndef is_dir_sep
 511 #define is_dir_sep git_is_dir_sep
 512 #endif
 513
 514 #ifndef offset_1st_component
 515 static inline int git_offset_1st_component(const char *path)
 516 {
 517         return is_dir_sep(path[0]);
 518 }
 519 #define offset_1st_component git_offset_1st_component
 520 #endif
 521
 522 #ifndef fspathcmp
 523 #define fspathcmp git_fspathcmp
 524 #endif
 525
 526 #ifndef fspathncmp
 527 #define fspathncmp git_fspathncmp
 528 #endif
 529
 530 #ifndef is_valid_path
 531 #define is_valid_path(path) 1
 532 #endif
 533
 534 #ifndef is_path_owned_by_current_user
 535
 536 #ifdef __TANDEM
 537 #define ROOT_UID 65535
 538 #else
 539 #define ROOT_UID 0
 540 #endif
 541
 542 /*
 543  * Do not use this function when
 544  * (1) geteuid() did not say we are running as 'root', or
 545  * (2) using this function will compromise the system.
 546  *
 547  * PORTABILITY WARNING:
 548  * This code assumes uid_t is unsigned because that is what sudo does.
 549  * If your uid_t type is signed and all your ids are positive then it
 550  * should all work fine.
 551  * If your version of sudo uses negative values for uid_t or it is
 552  * buggy and return an overflowed value in SUDO_UID, then git might
 553  * fail to grant access to your repository properly or even mistakenly
 554  * grant access to someone else.
 555  * In the unlikely scenario this happened to you, and that is how you
 556  * got to this message, we would like to know about it; so sent us an
 557  * email to git@vger.kernel.org indicating which platform you are
 558  * using and which version of sudo, so we can improve this logic and
 559  * maybe provide you with a patch that would prevent this issue again
 560  * in the future.
 561  */
 562 static inline void extract_id_from_env(const char *env, uid_t *id)
 563 {
 564         const char *real_uid = getenv(env);
 565
 566         /* discard anything empty to avoid a more complex check below */
 567         if (real_uid && *real_uid) {
 568                 char *endptr = NULL;
 569                 unsigned long env_id;
 570
 571                 errno = 0;
 572                 /* silent overflow errors could trigger a bug here */
 573                 env_id = strtoul(real_uid, &endptr, 10);
 574                 if (!*endptr && !errno)
 575                         *id = env_id;
 576         }
 577 }
 578
 579 static inline int is_path_owned_by_current_uid(const char *path,
 580                                                struct strbuf *report UNUSED)
 581 {
 582         struct stat st;
 583         uid_t euid;
 584
 585         if (lstat(path, &st))
 586                 return 0;
 587
 588         euid = geteuid();
 589         if (euid == ROOT_UID)
 590         {
 591                 if (st.st_uid == ROOT_UID)
 592                         return 1;
 593                 else
 594                         extract_id_from_env("SUDO_UID", &euid);
 595         }
 596
 597         return st.st_uid == euid;
 598 }
 599
 600 #define is_path_owned_by_current_user is_path_owned_by_current_uid
 601 #endif
 602
 603 #ifndef find_last_dir_sep
 604 static inline char *git_find_last_dir_sep(const char *path)
 605 {
 606         return strrchr(path, '/');
 607 }
 608 #define find_last_dir_sep git_find_last_dir_sep
 609 #endif
 610
 611 #ifndef has_dir_sep
 612 static inline int git_has_dir_sep(const char *path)
 613 {
 614         return !!strchr(path, '/');
 615 }
 616 #define has_dir_sep(path) git_has_dir_sep(path)
 617 #endif
 618
 619 #ifndef query_user_email
 620 #define query_user_email() NULL
 621 #endif
 622
 623 #ifdef __TANDEM
 624 #include <floss.h(floss_execl,floss_execlp,floss_execv,floss_execvp)>
 625 #include <floss.h(floss_getpwuid)>
 626 #ifndef NSIG
 627 /*
 628  * NonStop NSE and NSX do not provide NSIG. SIGGUARDIAN(99) is the highest
 629  * known, by detective work using kill -l as a list is all signals
 630  * instead of signal.h where it should be.
 631  */
 632 # define NSIG 100
 633 #endif
 634 #endif
 635
 636 #if defined(__HP_cc) && (__HP_cc >= 61000)
 637 #define NORETURN __attribute__((noreturn))
 638 #define NORETURN_PTR
 639 #elif defined(__GNUC__) && !defined(NO_NORETURN)
 640 #define NORETURN __attribute__((__noreturn__))
 641 #define NORETURN_PTR __attribute__((__noreturn__))
 642 #elif defined(_MSC_VER)
 643 #define NORETURN __declspec(noreturn)
 644 #define NORETURN_PTR
 645 #else
 646 #define NORETURN
 647 #define NORETURN_PTR
 648 #ifndef __GNUC__
 649 #ifndef __attribute__
 650 #define __attribute__(x)
 651 #endif
 652 #endif
 653 #endif
 654
 655 /* The sentinel attribute is valid from gcc version 4.0 */
 656 #if defined(__GNUC__) && (__GNUC__ >= 4)
 657 #define LAST_ARG_MUST_BE_NULL __attribute__((sentinel))
 658 /* warn_unused_result exists as of gcc 3.4.0, but be lazy and check 4.0 */
 659 #define RESULT_MUST_BE_USED __attribute__ ((warn_unused_result))
 660 #else
 661 #define LAST_ARG_MUST_BE_NULL
 662 #define RESULT_MUST_BE_USED
 663 #endif
 664
 665 /*
 666  * MAYBE_UNUSED marks a function parameter that may be unused, but
 667  * whose use is not an error.  It also can be used to annotate a
 668  * function, a variable, or a type that may be unused.
 669  *
 670  * Depending on a configuration, all uses of such a thing may become
 671  * #ifdef'ed away.  Marking it with UNUSED would give a warning in a
 672  * compilation where it is indeed used, and not marking it at all
 673  * would give a warning in a compilation where it is unused.  In such
 674  * a case, MAYBE_UNUSED is the appropriate annotation to use.
 675  */
 676 #define MAYBE_UNUSED __attribute__((__unused__))
 677
 678 #include "compat/bswap.h"
 679
 680 #include "wrapper.h"
 681
 682 /* General helper functions */
 683 NORETURN void usage(const char *err);
 684 NORETURN void usagef(const char *err, ...) __attribute__((format (printf, 1, 2)));
 685 NORETURN void die(const char *err, ...) __attribute__((format (printf, 1, 2)));
 686 NORETURN void die_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
 687 int die_message(const char *err, ...) __attribute__((format (printf, 1, 2)));
 688 int die_message_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
 689 int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
 690 int error_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
 691 void warning(const char *err, ...) __attribute__((format (printf, 1, 2)));
 692 void warning_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
 693
 694 #ifndef NO_OPENSSL
 695 #ifdef APPLE_COMMON_CRYPTO
 696 #include "compat/apple-common-crypto.h"
 697 #else
 698 #include <openssl/evp.h>
 699 #include <openssl/hmac.h>
 700 #endif /* APPLE_COMMON_CRYPTO */
 701 #include <openssl/x509v3.h>
 702 #endif /* NO_OPENSSL */
 703
 704 #ifdef HAVE_OPENSSL_CSPRNG
 705 #include <openssl/rand.h>
 706 #endif
 707
 708 /*
 709  * Let callers be aware of the constant return value; this can help
 710  * gcc with -Wuninitialized analysis. We restrict this trick to gcc, though,
 711  * because other compilers may be confused by this.
 712  */
 713 #if defined(__GNUC__)
 714 static inline int const_error(void)
 715 {
 716         return -1;
 717 }
 718 #define error(...) (error(__VA_ARGS__), const_error())
 719 #define error_errno(...) (error_errno(__VA_ARGS__), const_error())
 720 #endif
 721
 722 typedef void (*report_fn)(const char *, va_list params);
 723
 724 void set_die_routine(NORETURN_PTR report_fn routine);
 725 report_fn get_die_message_routine(void);
 726 void set_error_routine(report_fn routine);
 727 report_fn get_error_routine(void);
 728 void set_warn_routine(report_fn routine);
 729 report_fn get_warn_routine(void);
 730 void set_die_is_recursing_routine(int (*routine)(void));
 731
 732 /*
 733  * If the string "str" begins with the string found in "prefix", return true.
 734  * The "out" parameter is set to "str + strlen(prefix)" (i.e., to the point in
 735  * the string right after the prefix).
 736  *
 737  * Otherwise, return false and leave "out" untouched.
 738  *
 739  * Examples:
 740  *
 741  *   [extract branch name, fail if not a branch]
 742  *   if (!skip_prefix(ref, "refs/heads/", &branch)
 743  *      return -1;
 744  *
 745  *   [skip prefix if present, otherwise use whole string]
 746  *   skip_prefix(name, "refs/heads/", &name);
 747  */
 748 static inline bool skip_prefix(const char *str, const char *prefix,
 749                                const char **out)
 750 {
 751         do {
 752                 if (!*prefix) {
 753                         *out = str;
 754                         return true;
 755                 }
 756         } while (*str++ == *prefix++);
 757         return false;
 758 }
 759
 760 /*
 761  * Like skip_prefix, but promises never to read past "len" bytes of the input
 762  * buffer, and returns the remaining number of bytes in "out" via "outlen".
 763  */
 764 static inline bool skip_prefix_mem(const char *buf, size_t len,
 765                                    const char *prefix,
 766                                    const char **out, size_t *outlen)
 767 {
 768         size_t prefix_len = strlen(prefix);
 769         if (prefix_len <= len && !memcmp(buf, prefix, prefix_len)) {
 770                 *out = buf + prefix_len;
 771                 *outlen = len - prefix_len;
 772                 return true;
 773         }
 774         return false;
 775 }
 776
 777 /*
 778  * If buf ends with suffix, return true and subtract the length of the suffix
 779  * from *len. Otherwise, return false and leave *len untouched.
 780  */
 781 static inline bool strip_suffix_mem(const char *buf, size_t *len,
 782                                     const char *suffix)
 783 {
 784         size_t suflen = strlen(suffix);
 785         if (*len < suflen || memcmp(buf + (*len - suflen), suffix, suflen))
 786                 return false;
 787         *len -= suflen;
 788         return true;
 789 }
 790
 791 /*
 792  * If str ends with suffix, return true and set *len to the size of the string
 793  * without the suffix. Otherwise, return false and set *len to the size of the
 794  * string.
 795  *
 796  * Note that we do _not_ NUL-terminate str to the new length.
 797  */
 798 static inline bool strip_suffix(const char *str, const char *suffix,
 799                                 size_t *len)
 800 {
 801         *len = strlen(str);
 802         return strip_suffix_mem(str, len, suffix);
 803 }
 804
 805 #define SWAP(a, b) do {                                         \
 806         void *_swap_a_ptr = &(a);                               \
 807         void *_swap_b_ptr = &(b);                               \
 808         unsigned char _swap_buffer[sizeof(a)];                  \
 809         memcpy(_swap_buffer, _swap_a_ptr, sizeof(a));           \
 810         memcpy(_swap_a_ptr, _swap_b_ptr, sizeof(a) +            \
 811                BUILD_ASSERT_OR_ZERO(sizeof(a) == sizeof(b)));   \
 812         memcpy(_swap_b_ptr, _swap_buffer, sizeof(a));           \
 813 } while (0)
 814
 815 #if defined(NO_MMAP) || defined(USE_WIN32_MMAP)
 816
 817 #ifndef PROT_READ
 818 #define PROT_READ 1
 819 #define PROT_WRITE 2
 820 #define MAP_PRIVATE 1
 821 #endif
 822
 823 #define mmap git_mmap
 824 #define munmap git_munmap
 825 void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset);
 826 int git_munmap(void *start, size_t length);
 827
 828 #else /* NO_MMAP || USE_WIN32_MMAP */
 829
 830 #include <sys/mman.h>
 831
 832 #endif /* NO_MMAP || USE_WIN32_MMAP */
 833
 834 #ifdef NO_MMAP
 835
 836 /* This value must be multiple of (pagesize * 2) */
 837 #define DEFAULT_PACKED_GIT_WINDOW_SIZE (1 * 1024 * 1024)
 838
 839 #else /* NO_MMAP */
 840
 841 /* This value must be multiple of (pagesize * 2) */
 842 #define DEFAULT_PACKED_GIT_WINDOW_SIZE \
 843         (sizeof(void*) >= 8 \
 844                 ?  1 * 1024 * 1024 * 1024 \
 845                 : 32 * 1024 * 1024)
 846
 847 #endif /* NO_MMAP */
 848
 849 #ifndef MAP_FAILED
 850 #define MAP_FAILED ((void *)-1)
 851 #endif
 852
 853 #ifdef NO_ST_BLOCKS_IN_STRUCT_STAT
 854 #define on_disk_bytes(st) ((st).st_size)
 855 #else
 856 #define on_disk_bytes(st) ((st).st_blocks * 512)
 857 #endif
 858
 859 #ifdef NEEDS_MODE_TRANSLATION
 860 #undef S_IFMT
 861 #undef S_IFREG
 862 #undef S_IFDIR
 863 #undef S_IFLNK
 864 #undef S_IFBLK
 865 #undef S_IFCHR
 866 #undef S_IFIFO
 867 #undef S_IFSOCK
 868 #define S_IFMT   0170000
 869 #define S_IFREG  0100000
 870 #define S_IFDIR  0040000
 871 #define S_IFLNK  0120000
 872 #define S_IFBLK  0060000
 873 #define S_IFCHR  0020000
 874 #define S_IFIFO  0010000
 875 #define S_IFSOCK 0140000
 876 #ifdef stat
 877 #undef stat
 878 #endif
 879 #define stat(path, buf) git_stat(path, buf)
 880 int git_stat(const char *, struct stat *);
 881 #ifdef fstat
 882 #undef fstat
 883 #endif
 884 #define fstat(fd, buf) git_fstat(fd, buf)
 885 int git_fstat(int, struct stat *);
 886 #ifdef lstat
 887 #undef lstat
 888 #endif
 889 #define lstat(path, buf) git_lstat(path, buf)
 890 int git_lstat(const char *, struct stat *);
 891 #endif
 892
 893 #define DEFAULT_PACKED_GIT_LIMIT \
 894         ((1024L * 1024L) * (size_t)(sizeof(void*) >= 8 ? (32 * 1024L * 1024L) : 256))
 895
 896 #ifdef NO_PREAD
 897 #define pread git_pread
 898 ssize_t git_pread(int fd, void *buf, size_t count, off_t offset);
 899 #endif
 900
 901 #ifdef NO_SETENV
 902 #define setenv gitsetenv
 903 int gitsetenv(const char *, const char *, int);
 904 #endif
 905
 906 #ifdef NO_MKDTEMP
 907 #define mkdtemp gitmkdtemp
 908 char *gitmkdtemp(char *);
 909 #endif
 910
 911 #ifdef NO_UNSETENV
 912 #define unsetenv gitunsetenv
 913 int gitunsetenv(const char *);
 914 #endif
 915
 916 #ifdef NO_STRCASESTR
 917 #define strcasestr gitstrcasestr
 918 char *gitstrcasestr(const char *haystack, const char *needle);
 919 #endif
 920
 921 #ifdef NO_STRLCPY
 922 #define strlcpy gitstrlcpy
 923 size_t gitstrlcpy(char *, const char *, size_t);
 924 #endif
 925
 926 #ifdef NO_STRTOUMAX
 927 #define strtoumax gitstrtoumax
 928 uintmax_t gitstrtoumax(const char *, char **, int);
 929 #define strtoimax gitstrtoimax
 930 intmax_t gitstrtoimax(const char *, char **, int);
 931 #endif
 932
 933 #ifdef NO_HSTRERROR
 934 #define hstrerror githstrerror
 935 const char *githstrerror(int herror);
 936 #endif
 937
 938 #ifdef NO_MEMMEM
 939 #define memmem gitmemmem
 940 void *gitmemmem(const void *haystack, size_t haystacklen,
 941                 const void *needle, size_t needlelen);
 942 #endif
 943
 944 #ifdef OVERRIDE_STRDUP
 945 #ifdef strdup
 946 #undef strdup
 947 #endif
 948 #define strdup gitstrdup
 949 char *gitstrdup(const char *s);
 950 #endif
 951
 952 #ifdef NO_GETPAGESIZE
 953 #define getpagesize() sysconf(_SC_PAGESIZE)
 954 #endif
 955
 956 #ifndef O_CLOEXEC
 957 #define O_CLOEXEC 0
 958 #endif
 959
 960 #ifdef FREAD_READS_DIRECTORIES
 961 # if !defined(SUPPRESS_FOPEN_REDEFINITION)
 962 #  ifdef fopen
 963 #   undef fopen
 964 #  endif
 965 #  define fopen(a,b) git_fopen(a,b)
 966 # endif
 967 FILE *git_fopen(const char*, const char*);
 968 #endif
 969
 970 #ifdef SNPRINTF_RETURNS_BOGUS
 971 #ifdef snprintf
 972 #undef snprintf
 973 #endif
 974 #define snprintf git_snprintf
 975 int git_snprintf(char *str, size_t maxsize,
 976                  const char *format, ...);
 977 #ifdef vsnprintf
 978 #undef vsnprintf
 979 #endif
 980 #define vsnprintf git_vsnprintf
 981 int git_vsnprintf(char *str, size_t maxsize,
 982                   const char *format, va_list ap);
 983 #endif
 984
 985 #ifdef OPEN_RETURNS_EINTR
 986 #undef open
 987 #define open git_open_with_retry
 988 int git_open_with_retry(const char *path, int flag, ...);
 989 #endif
 990
 991 #ifdef __GLIBC_PREREQ
 992 #if __GLIBC_PREREQ(2, 1)
 993 #define HAVE_STRCHRNUL
 994 #endif
 995 #endif
 996
 997 #ifndef HAVE_STRCHRNUL
 998 #define strchrnul gitstrchrnul
 999 static inline char *gitstrchrnul(const char *s, int c)
1000 {
1001         while (*s && *s != c)
1002                 s++;
1003         return (char *)s;
1004 }
1005 #endif
1006
1007 #ifdef NO_INET_PTON
1008 int inet_pton(int af, const char *src, void *dst);
1009 #endif
1010
1011 #ifdef NO_INET_NTOP
1012 const char *inet_ntop(int af, const void *src, char *dst, size_t size);
1013 #endif
1014
1015 #ifdef NO_PTHREADS
1016 #define atexit git_atexit
1017 int git_atexit(void (*handler)(void));
1018 #endif
1019
1020 static inline size_t st_add(size_t a, size_t b)
1021 {
1022         if (unsigned_add_overflows(a, b))
1023                 die("size_t overflow: %"PRIuMAX" + %"PRIuMAX,
1024                     (uintmax_t)a, (uintmax_t)b);
1025         return a + b;
1026 }
1027 #define st_add3(a,b,c)   st_add(st_add((a),(b)),(c))
1028 #define st_add4(a,b,c,d) st_add(st_add3((a),(b),(c)),(d))
1029
1030 static inline size_t st_mult(size_t a, size_t b)
1031 {
1032         if (unsigned_mult_overflows(a, b))
1033                 die("size_t overflow: %"PRIuMAX" * %"PRIuMAX,
1034                     (uintmax_t)a, (uintmax_t)b);
1035         return a * b;
1036 }
1037
1038 static inline size_t st_sub(size_t a, size_t b)
1039 {
1040         if (a < b)
1041                 die("size_t underflow: %"PRIuMAX" - %"PRIuMAX,
1042                     (uintmax_t)a, (uintmax_t)b);
1043         return a - b;
1044 }
1045
1046 static inline size_t st_left_shift(size_t a, unsigned shift)
1047 {
1048         if (unsigned_left_shift_overflows(a, shift))
1049                 die("size_t overflow: %"PRIuMAX" << %u",
1050                     (uintmax_t)a, shift);
1051         return a << shift;
1052 }
1053
1054 static inline unsigned long cast_size_t_to_ulong(size_t a)
1055 {
1056         if (a != (unsigned long)a)
1057                 die("object too large to read on this platform: %"
1058                     PRIuMAX" is cut off to %lu",
1059                     (uintmax_t)a, (unsigned long)a);
1060         return (unsigned long)a;
1061 }
1062
1063 static inline uint32_t cast_size_t_to_uint32_t(size_t a)
1064 {
1065         if (a != (uint32_t)a)
1066                 die("object too large to read on this platform: %"
1067                     PRIuMAX" is cut off to %u",
1068                     (uintmax_t)a, (uint32_t)a);
1069         return (uint32_t)a;
1070 }
1071
1072 static inline int cast_size_t_to_int(size_t a)
1073 {
1074         if (a > INT_MAX)
1075                 die("number too large to represent as int on this platform: %"PRIuMAX,
1076                     (uintmax_t)a);
1077         return (int)a;
1078 }
1079
1080 /*
1081  * Limit size of IO chunks, because huge chunks only cause pain.  OS X
1082  * 64-bit is buggy, returning EINVAL if len >= INT_MAX; and even in
1083  * the absence of bugs, large chunks can result in bad latencies when
1084  * you decide to kill the process.
1085  *
1086  * We pick 8 MiB as our default, but if the platform defines SSIZE_MAX
1087  * that is smaller than that, clip it to SSIZE_MAX, as a call to
1088  * read(2) or write(2) larger than that is allowed to fail.  As the last
1089  * resort, we allow a port to pass via CFLAGS e.g. "-DMAX_IO_SIZE=value"
1090  * to override this, if the definition of SSIZE_MAX given by the platform
1091  * is broken.
1092  */
1093 #ifndef MAX_IO_SIZE
1094 # define MAX_IO_SIZE_DEFAULT (8*1024*1024)
1095 # if defined(SSIZE_MAX) && (SSIZE_MAX < MAX_IO_SIZE_DEFAULT)
1096 #  define MAX_IO_SIZE SSIZE_MAX
1097 # else
1098 #  define MAX_IO_SIZE MAX_IO_SIZE_DEFAULT
1099 # endif
1100 #endif
1101
1102 #ifdef HAVE_ALLOCA_H
1103 # include <alloca.h>
1104 # define xalloca(size)      (alloca(size))
1105 # define xalloca_free(p)    do {} while (0)
1106 #else
1107 # define xalloca(size)      (xmalloc(size))
1108 # define xalloca_free(p)    (free(p))
1109 #endif
1110
1111 /*
1112  * FREE_AND_NULL(ptr) is like free(ptr) followed by ptr = NULL. Note
1113  * that ptr is used twice, so don't pass e.g. ptr++.
1114  */
1115 #define FREE_AND_NULL(p) do { free(p); (p) = NULL; } while (0)
1116
1117 #define ALLOC_ARRAY(x, alloc) (x) = xmalloc(st_mult(sizeof(*(x)), (alloc)))
1118 #define CALLOC_ARRAY(x, alloc) (x) = xcalloc((alloc), sizeof(*(x)))
1119 #define REALLOC_ARRAY(x, alloc) (x) = xrealloc((x), st_mult(sizeof(*(x)), (alloc)))
1120
1121 #define COPY_ARRAY(dst, src, n) copy_array((dst), (src), (n), sizeof(*(dst)) + \
1122         BARF_UNLESS_COPYABLE((dst), (src)))
1123 static inline void copy_array(void *dst, const void *src, size_t n, size_t size)
1124 {
1125         if (n)
1126                 memcpy(dst, src, st_mult(size, n));
1127 }
1128
1129 #define MOVE_ARRAY(dst, src, n) move_array((dst), (src), (n), sizeof(*(dst)) + \
1130         BARF_UNLESS_COPYABLE((dst), (src)))
1131 static inline void move_array(void *dst, const void *src, size_t n, size_t size)
1132 {
1133         if (n)
1134                 memmove(dst, src, st_mult(size, n));
1135 }
1136
1137 #define DUP_ARRAY(dst, src, n) do { \
1138         size_t dup_array_n_ = (n); \
1139         COPY_ARRAY(ALLOC_ARRAY((dst), dup_array_n_), (src), dup_array_n_); \
1140 } while (0)
1141
1142 /*
1143  * These functions help you allocate structs with flex arrays, and copy
1144  * the data directly into the array. For example, if you had:
1145  *
1146  *   struct foo {
1147  *     int bar;
1148  *     char name[FLEX_ARRAY];
1149  *   };
1150  *
1151  * you can do:
1152  *
1153  *   struct foo *f;
1154  *   FLEX_ALLOC_MEM(f, name, src, len);
1155  *
1156  * to allocate a "foo" with the contents of "src" in the "name" field.
1157  * The resulting struct is automatically zero'd, and the flex-array field
1158  * is NUL-terminated (whether the incoming src buffer was or not).
1159  *
1160  * The FLEXPTR_* variants operate on structs that don't use flex-arrays,
1161  * but do want to store a pointer to some extra data in the same allocated
1162  * block. For example, if you have:
1163  *
1164  *   struct foo {
1165  *     char *name;
1166  *     int bar;
1167  *   };
1168  *
1169  * you can do:
1170  *
1171  *   struct foo *f;
1172  *   FLEXPTR_ALLOC_STR(f, name, src);
1173  *
1174  * and "name" will point to a block of memory after the struct, which will be
1175  * freed along with the struct (but the pointer can be repointed anywhere).
1176  *
1177  * The *_STR variants accept a string parameter rather than a ptr/len
1178  * combination.
1179  *
1180  * Note that these macros will evaluate the first parameter multiple
1181  * times, and it must be assignable as an lvalue.
1182  */
1183 #define FLEX_ALLOC_MEM(x, flexname, buf, len) do { \
1184         size_t flex_array_len_ = (len); \
1185         (x) = xcalloc(1, st_add3(sizeof(*(x)), flex_array_len_, 1)); \
1186         memcpy((void *)(x)->flexname, (buf), flex_array_len_); \
1187 } while (0)
1188 #define FLEXPTR_ALLOC_MEM(x, ptrname, buf, len) do { \
1189         size_t flex_array_len_ = (len); \
1190         (x) = xcalloc(1, st_add3(sizeof(*(x)), flex_array_len_, 1)); \
1191         memcpy((x) + 1, (buf), flex_array_len_); \
1192         (x)->ptrname = (void *)((x)+1); \
1193 } while(0)
1194 #define FLEX_ALLOC_STR(x, flexname, str) \
1195         FLEX_ALLOC_MEM((x), flexname, (str), strlen(str))
1196 #define FLEXPTR_ALLOC_STR(x, ptrname, str) \
1197         FLEXPTR_ALLOC_MEM((x), ptrname, (str), strlen(str))
1198
1199 #define alloc_nr(x) (((x)+16)*3/2)
1200
1201 /**
1202  * Dynamically growing an array using realloc() is error prone and boring.
1203  *
1204  * Define your array with:
1205  *
1206  * - a pointer (`item`) that points at the array, initialized to `NULL`
1207  *   (although please name the variable based on its contents, not on its
1208  *   type);
1209  *
1210  * - an integer variable (`alloc`) that keeps track of how big the current
1211  *   allocation is, initialized to `0`;
1212  *
1213  * - another integer variable (`nr`) to keep track of how many elements the
1214  *   array currently has, initialized to `0`.
1215  *
1216  * Then before adding `n`th element to the item, call `ALLOC_GROW(item, n,
1217  * alloc)`.  This ensures that the array can hold at least `n` elements by
1218  * calling `realloc(3)` and adjusting `alloc` variable.
1219  *
1220  * ------------
1221  * sometype *item;
1222  * size_t nr;
1223  * size_t alloc
1224  *
1225  * for (i = 0; i < nr; i++)
1226  *      if (we like item[i] already)
1227  *              return;
1228  *
1229  * // we did not like any existing one, so add one
1230  * ALLOC_GROW(item, nr + 1, alloc);
1231  * item[nr++] = value you like;
1232  * ------------
1233  *
1234  * You are responsible for updating the `nr` variable.
1235  *
1236  * If you need to specify the number of elements to allocate explicitly
1237  * then use the macro `REALLOC_ARRAY(item, alloc)` instead of `ALLOC_GROW`.
1238  *
1239  * Consider using ALLOC_GROW_BY instead of ALLOC_GROW as it has some
1240  * added niceties.
1241  *
1242  * DO NOT USE any expression with side-effect for 'x', 'nr', or 'alloc'.
1243  */
1244 #define ALLOC_GROW(x, nr, alloc) \
1245         do { \
1246                 if ((nr) > alloc) { \
1247                         if (alloc_nr(alloc) < (nr)) \
1248                                 alloc = (nr); \
1249                         else \
1250                                 alloc = alloc_nr(alloc); \
1251                         REALLOC_ARRAY(x, alloc); \
1252                 } \
1253         } while (0)
1254
1255 /*
1256  * Similar to ALLOC_GROW but handles updating of the nr value and
1257  * zeroing the bytes of the newly-grown array elements.
1258  *
1259  * DO NOT USE any expression with side-effect for any of the
1260  * arguments.
1261  */
1262 #define ALLOC_GROW_BY(x, nr, increase, alloc) \
1263         do { \
1264                 if (increase) { \
1265                         size_t new_nr = nr + (increase); \
1266                         if (new_nr < nr) \
1267                                 BUG("negative growth in ALLOC_GROW_BY"); \
1268                         ALLOC_GROW(x, new_nr, alloc); \
1269                         memset((x) + nr, 0, sizeof(*(x)) * (increase)); \
1270                         nr = new_nr; \
1271                 } \
1272         } while (0)
1273
1274 static inline char *xstrdup_or_null(const char *str)
1275 {
1276         return str ? xstrdup(str) : NULL;
1277 }
1278
1279 static inline size_t xsize_t(off_t len)
1280 {
1281         if (len < 0 || (uintmax_t) len > SIZE_MAX)
1282                 die("Cannot handle files this big");
1283         return (size_t) len;
1284 }
1285
1286 #ifndef HOST_NAME_MAX
1287 #define HOST_NAME_MAX 256
1288 #endif
1289
1290 #include "sane-ctype.h"
1291
1292 /*
1293  * Like skip_prefix, but compare case-insensitively. Note that the comparison
1294  * is done via tolower(), so it is strictly ASCII (no multi-byte characters or
1295  * locale-specific conversions).
1296  */
1297 static inline int skip_iprefix(const char *str, const char *prefix,
1298                                const char **out)
1299 {
1300         do {
1301                 if (!*prefix) {
1302                         *out = str;
1303                         return 1;
1304                 }
1305         } while (tolower(*str++) == tolower(*prefix++));
1306         return 0;
1307 }
1308
1309 /*
1310  * Like skip_prefix_mem, but compare case-insensitively. Note that the
1311  * comparison is done via tolower(), so it is strictly ASCII (no multi-byte
1312  * characters or locale-specific conversions).
1313  */
1314 static inline int skip_iprefix_mem(const char *buf, size_t len,
1315                                    const char *prefix,
1316                                    const char **out, size_t *outlen)
1317 {
1318         do {
1319                 if (!*prefix) {
1320                         *out = buf;
1321                         *outlen = len;
1322                         return 1;
1323                 }
1324         } while (len-- > 0 && tolower(*buf++) == tolower(*prefix++));
1325         return 0;
1326 }
1327
1328 static inline int strtoul_ui(char const *s, int base, unsigned int *result)
1329 {
1330         unsigned long ul;
1331         char *p;
1332
1333         errno = 0;
1334         /* negative values would be accepted by strtoul */
1335         if (strchr(s, '-'))
1336                 return -1;
1337         ul = strtoul(s, &p, base);
1338         if (errno || *p || p == s || (unsigned int) ul != ul)
1339                 return -1;
1340         *result = ul;
1341         return 0;
1342 }
1343
1344 static inline int strtol_i(char const *s, int base, int *result)
1345 {
1346         long ul;
1347         char *p;
1348
1349         errno = 0;
1350         ul = strtol(s, &p, base);
1351         if (errno || *p || p == s || (int) ul != ul)
1352                 return -1;
1353         *result = ul;
1354         return 0;
1355 }
1356
1357 void git_stable_qsort(void *base, size_t nmemb, size_t size,
1358                       int(*compar)(const void *, const void *));
1359 #ifdef INTERNAL_QSORT
1360 #define qsort git_stable_qsort
1361 #endif
1362
1363 #define QSORT(base, n, compar) sane_qsort((base), (n), sizeof(*(base)), compar)
1364 static inline void sane_qsort(void *base, size_t nmemb, size_t size,
1365                               int(*compar)(const void *, const void *))
1366 {
1367         if (nmemb > 1)
1368                 qsort(base, nmemb, size, compar);
1369 }
1370
1371 #define STABLE_QSORT(base, n, compar) \
1372         git_stable_qsort((base), (n), sizeof(*(base)), compar)
1373
1374 #ifndef HAVE_ISO_QSORT_S
1375 int git_qsort_s(void *base, size_t nmemb, size_t size,
1376                 int (*compar)(const void *, const void *, void *), void *ctx);
1377 #define qsort_s git_qsort_s
1378 #endif
1379
1380 #define QSORT_S(base, n, compar, ctx) do {                      \
1381         if (qsort_s((base), (n), sizeof(*(base)), compar, ctx)) \
1382                 BUG("qsort_s() failed");                        \
1383 } while (0)
1384
1385 #ifndef REG_STARTEND
1386 #error "Git requires REG_STARTEND support. Compile with NO_REGEX=NeedsStartEnd"
1387 #endif
1388
1389 static inline int regexec_buf(const regex_t *preg, const char *buf, size_t size,
1390                               size_t nmatch, regmatch_t pmatch[], int eflags)
1391 {
1392         assert(nmatch > 0 && pmatch);
1393         pmatch[0].rm_so = 0;
1394         pmatch[0].rm_eo = size;
1395         return regexec(preg, buf, nmatch, pmatch, eflags | REG_STARTEND);
1396 }
1397
1398 #ifdef USE_ENHANCED_BASIC_REGULAR_EXPRESSIONS
1399 int git_regcomp(regex_t *preg, const char *pattern, int cflags);
1400 #define regcomp git_regcomp
1401 #endif
1402
1403 #ifndef DIR_HAS_BSD_GROUP_SEMANTICS
1404 # define FORCE_DIR_SET_GID S_ISGID
1405 #else
1406 # define FORCE_DIR_SET_GID 0
1407 #endif
1408
1409 #ifdef NO_NSEC
1410 #undef USE_NSEC
1411 #define ST_CTIME_NSEC(st) 0
1412 #define ST_MTIME_NSEC(st) 0
1413 #else
1414 #ifdef USE_ST_TIMESPEC
1415 #define ST_CTIME_NSEC(st) ((unsigned int)((st).st_ctimespec.tv_nsec))
1416 #define ST_MTIME_NSEC(st) ((unsigned int)((st).st_mtimespec.tv_nsec))
1417 #else
1418 #define ST_CTIME_NSEC(st) ((unsigned int)((st).st_ctim.tv_nsec))
1419 #define ST_MTIME_NSEC(st) ((unsigned int)((st).st_mtim.tv_nsec))
1420 #endif
1421 #endif
1422
1423 #ifdef UNRELIABLE_FSTAT
1424 #define fstat_is_reliable() 0
1425 #else
1426 #define fstat_is_reliable() 1
1427 #endif
1428
1429 #ifndef va_copy
1430 /*
1431  * Since an obvious implementation of va_list would be to make it a
1432  * pointer into the stack frame, a simple assignment will work on
1433  * many systems.  But let's try to be more portable.
1434  */
1435 #ifdef __va_copy
1436 #define va_copy(dst, src) __va_copy(dst, src)
1437 #else
1438 #define va_copy(dst, src) ((dst) = (src))
1439 #endif
1440 #endif
1441
1442 /* usage.c: only to be used for testing BUG() implementation (see test-tool) */
1443 extern int BUG_exit_code;
1444
1445 /* usage.c: if bug() is called we should have a BUG_if_bug() afterwards */
1446 extern int bug_called_must_BUG;
1447
1448 __attribute__((format (printf, 3, 4))) NORETURN
1449 void BUG_fl(const char *file, int line, const char *fmt, ...);
1450 #define BUG(...) BUG_fl(__FILE__, __LINE__, __VA_ARGS__)
1451 __attribute__((format (printf, 3, 4)))
1452 void bug_fl(const char *file, int line, const char *fmt, ...);
1453 #define bug(...) bug_fl(__FILE__, __LINE__, __VA_ARGS__)
1454 #define BUG_if_bug(...) do { \
1455         if (bug_called_must_BUG) \
1456                 BUG_fl(__FILE__, __LINE__, __VA_ARGS__); \
1457 } while (0)
1458
1459 #ifndef FSYNC_METHOD_DEFAULT
1460 #ifdef __APPLE__
1461 #define FSYNC_METHOD_DEFAULT FSYNC_METHOD_WRITEOUT_ONLY
1462 #else
1463 #define FSYNC_METHOD_DEFAULT FSYNC_METHOD_FSYNC
1464 #endif
1465 #endif
1466
1467 #ifndef SHELL_PATH
1468 # define SHELL_PATH "/bin/sh"
1469 #endif
1470
1471 #ifndef _POSIX_THREAD_SAFE_FUNCTIONS
1472 static inline void git_flockfile(FILE *fh UNUSED)
1473 {
1474         ; /* nothing */
1475 }
1476 static inline void git_funlockfile(FILE *fh UNUSED)
1477 {
1478         ; /* nothing */
1479 }
1480 #undef flockfile
1481 #undef funlockfile
1482 #undef getc_unlocked
1483 #define flockfile(fh) git_flockfile(fh)
1484 #define funlockfile(fh) git_funlockfile(fh)
1485 #define getc_unlocked(fh) getc(fh)
1486 #endif
1487
1488 #ifdef FILENO_IS_A_MACRO
1489 int git_fileno(FILE *stream);
1490 # ifndef COMPAT_CODE_FILENO
1491 #  undef fileno
1492 #  define fileno(p) git_fileno(p)
1493 # endif
1494 #endif
1495
1496 #ifdef NEED_ACCESS_ROOT_HANDLER
1497 int git_access(const char *path, int mode);
1498 # ifndef COMPAT_CODE_ACCESS
1499 #  ifdef access
1500 #  undef access
1501 #  endif
1502 #  define access(path, mode) git_access(path, mode)
1503 # endif
1504 #endif
1505
1506 /*
1507  * Our code often opens a path to an optional file, to work on its
1508  * contents when we can successfully open it.  We can ignore a failure
1509  * to open if such an optional file does not exist, but we do want to
1510  * report a failure in opening for other reasons (e.g. we got an I/O
1511  * error, or the file is there, but we lack the permission to open).
1512  *
1513  * Call this function after seeing an error from open() or fopen() to
1514  * see if the errno indicates a missing file that we can safely ignore.
1515  */
1516 static inline int is_missing_file_error(int errno_)
1517 {
1518         return (errno_ == ENOENT || errno_ == ENOTDIR);
1519 }
1520
1521 int cmd_main(int, const char **);
1522
1523 /*
1524  * Intercept all calls to exit() and route them to trace2 to
1525  * optionally emit a message before calling the real exit().
1526  */
1527 int common_exit(const char *file, int line, int code);
1528 #define exit(code) exit(common_exit(__FILE__, __LINE__, (code)))
1529
1530 /*
1531  * You can mark a stack variable with UNLEAK(var) to avoid it being
1532  * reported as a leak by tools like LSAN or valgrind. The argument
1533  * should generally be the variable itself (not its address and not what
1534  * it points to). It's safe to use this on pointers which may already
1535  * have been freed, or on pointers which may still be in use.
1536  *
1537  * Use this _only_ for a variable that leaks by going out of scope at
1538  * program exit (so only from cmd_* functions or their direct helpers).
1539  * Normal functions, especially those which may be called multiple
1540  * times, should actually free their memory. This is only meant as
1541  * an annotation, and does nothing in non-leak-checking builds.
1542  */
1543 #ifdef SUPPRESS_ANNOTATED_LEAKS
1544 void unleak_memory(const void *ptr, size_t len);
1545 #define UNLEAK(var) unleak_memory(&(var), sizeof(var))
1546 #else
1547 #define UNLEAK(var) do {} while (0)
1548 #endif
1549
1550 #define z_const
1551 #include <zlib.h>
1552
1553 #if ZLIB_VERNUM < 0x1290
1554 /*
1555  * This is uncompress2, which is only available in zlib >= 1.2.9
1556  * (released as of early 2017). See compat/zlib-uncompress2.c.
1557  */
1558 int uncompress2(Bytef *dest, uLongf *destLen, const Bytef *source,
1559                 uLong *sourceLen);
1560 #endif
1561
1562 /*
1563  * This include must come after system headers, since it introduces macros that
1564  * replace system names.
1565  */
1566 #include "banned.h"
1567
1568 /*
1569  * container_of - Get the address of an object containing a field.
1570  *
1571  * @ptr: pointer to the field.
1572  * @type: type of the object.
1573  * @member: name of the field within the object.
1574  */
1575 #define container_of(ptr, type, member) \
1576         ((type *) ((char *)(ptr) - offsetof(type, member)))
1577
1578 /*
1579  * helper function for `container_of_or_null' to avoid multiple
1580  * evaluation of @ptr
1581  */
1582 static inline void *container_of_or_null_offset(void *ptr, size_t offset)
1583 {
1584         return ptr ? (char *)ptr - offset : NULL;
1585 }
1586
1587 /*
1588  * like `container_of', but allows returned value to be NULL
1589  */
1590 #define container_of_or_null(ptr, type, member) \
1591         (type *)container_of_or_null_offset(ptr, offsetof(type, member))
1592
1593 /*
1594  * like offsetof(), but takes a pointer to a variable of type which
1595  * contains @member, instead of a specified type.
1596  * @ptr is subject to multiple evaluation since we can't rely on __typeof__
1597  * everywhere.
1598  */
1599 #if defined(__GNUC__) /* clang sets this, too */
1600 #define OFFSETOF_VAR(ptr, member) offsetof(__typeof__(*ptr), member)
1601 #else /* !__GNUC__ */
1602 #define OFFSETOF_VAR(ptr, member) \
1603         ((uintptr_t)&(ptr)->member - (uintptr_t)(ptr))
1604 #endif /* !__GNUC__ */
1605
1606 #endif