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