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