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