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