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 #else
 101 # define BARF_UNLESS_AN_ARRAY(arr) 0
 102 #endif
 103 /*
 104  * ARRAY_SIZE - get the number of elements in a visible array
 105  * @x: the array whose size you want.
 106  *
 107  * This does not work on pointers, or arrays declared as [], or
 108  * function parameters.  With correct compiler support, such usage
 109  * will cause a build error (see the build_assert_or_zero macro).
 110  */
 111 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]) + BARF_UNLESS_AN_ARRAY(x))
 112
 113 #define bitsizeof(x)  (CHAR_BIT * sizeof(x))
 114
 115 #define maximum_signed_value_of_type(a) \
 116     (INTMAX_MAX >> (bitsizeof(intmax_t) - bitsizeof(a)))
 117
 118 #define maximum_unsigned_value_of_type(a) \
 119     (UINTMAX_MAX >> (bitsizeof(uintmax_t) - bitsizeof(a)))
 120
 121 /*
 122  * Signed integer overflow is undefined in C, so here's a helper macro
 123  * to detect if the sum of two integers will overflow.
 124  *
 125  * Requires: a >= 0, typeof(a) equals typeof(b)
 126  */
 127 #define signed_add_overflows(a, b) \
 128     ((b) > maximum_signed_value_of_type(a) - (a))
 129
 130 #define unsigned_add_overflows(a, b) \
 131     ((b) > maximum_unsigned_value_of_type(a) - (a))
 132
 133 /*
 134  * Returns true if the multiplication of "a" and "b" will
 135  * overflow. The types of "a" and "b" must match and must be unsigned.
 136  * Note that this macro evaluates "a" twice!
 137  */
 138 #define unsigned_mult_overflows(a, b) \
 139     ((a) && (b) > maximum_unsigned_value_of_type(a) / (a))
 140
 141 /*
 142  * Returns true if the left shift of "a" by "shift" bits will
 143  * overflow. The type of "a" must be unsigned.
 144  */
 145 #define unsigned_left_shift_overflows(a, shift) \
 146     ((shift) < bitsizeof(a) && \
 147      (a) > maximum_unsigned_value_of_type(a) >> (shift))
 148
 149 #ifdef __GNUC__
 150 #define TYPEOF(x) (__typeof__(x))
 151 #else
 152 #define TYPEOF(x)
 153 #endif
 154
 155 #define MSB(x, bits) ((x) & TYPEOF(x)(~0ULL << (bitsizeof(x) - (bits))))
 156 #define HAS_MULTI_BITS(i)  ((i) & ((i) - 1))  /* checks if an integer has more than 1 bit set */
 157
 158 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
 159
 160 /* Approximation of the length of the decimal representation of this type. */
 161 #define decimal_length(x)       ((int)(sizeof(x) * 2.56 + 0.5) + 1)
 162
 163 #ifdef __MINGW64__
 164 #define _POSIX_C_SOURCE 1
 165 #elif defined(__sun__)
 166  /*
 167   * On Solaris, when _XOPEN_EXTENDED is set, its header file
 168   * forces the programs to be XPG4v2, defeating any _XOPEN_SOURCE
 169   * setting to say we are XPG5 or XPG6.  Also on Solaris,
 170   * XPG6 programs must be compiled with a c99 compiler, while
 171   * non XPG6 programs must be compiled with a pre-c99 compiler.
 172   */
 173 # if __STDC_VERSION__ - 0 >= 199901L
 174 # define _XOPEN_SOURCE 600
 175 # else
 176 # define _XOPEN_SOURCE 500
 177 # endif
 178 #elif !defined(__APPLE__) && !defined(__FreeBSD__) && !defined(__USLC__) && \
 179       !defined(_M_UNIX) && !defined(__sgi) && !defined(__DragonFly__) && \
 180       !defined(__TANDEM) && !defined(__QNX__) && !defined(__MirBSD__) && \
 181       !defined(__CYGWIN__)
 182 #define _XOPEN_SOURCE 600 /* glibc2 and AIX 5.3L need 500, OpenBSD needs 600 for S_ISLNK() */
 183 #define _XOPEN_SOURCE_EXTENDED 1 /* AIX 5.3L needs this */
 184 #endif
 185 #define _ALL_SOURCE 1
 186 #define _GNU_SOURCE 1
 187 #define _BSD_SOURCE 1
 188 #define _DEFAULT_SOURCE 1
 189 #define _NETBSD_SOURCE 1
 190 #define _SGI_SOURCE 1
 191
 192 #if defined(__GNUC__)
 193 #define UNUSED __attribute__((unused)) \
 194         __attribute__((deprecated ("parameter declared as UNUSED")))
 195 #else
 196 #define UNUSED
 197 #endif
 198
 199 #if defined(WIN32) && !defined(__CYGWIN__) /* Both MinGW and MSVC */
 200 # if !defined(_WIN32_WINNT)
 201 #  define _WIN32_WINNT 0x0600
 202 # endif
 203 #define WIN32_LEAN_AND_MEAN  /* stops windows.h including winsock.h */
 204 #include <winsock2.h>
 205 #ifndef NO_UNIX_SOCKETS
 206 #include <afunix.h>
 207 #endif
 208 #include <windows.h>
 209 #define GIT_WINDOWS_NATIVE
 210 #endif
 211
 212 #include <unistd.h>
 213 #include <stdio.h>
 214 #include <sys/stat.h>
 215 #include <fcntl.h>
 216 #include <stddef.h>
 217 #include <stdlib.h>
 218 #include <stdarg.h>
 219 #include <string.h>
 220 #ifdef HAVE_STRINGS_H
 221 #include <strings.h> /* for strcasecmp() */
 222 #endif
 223 #include <errno.h>
 224 #include <limits.h>
 225 #ifdef NEEDS_SYS_PARAM_H
 226 #include <sys/param.h>
 227 #endif
 228 #include <sys/types.h>
 229 #include <dirent.h>
 230 #include <sys/time.h>
 231 #include <time.h>
 232 #include <signal.h>
 233 #include <assert.h>
 234 #include <regex.h>
 235 #include <utime.h>
 236 #include <syslog.h>
 237 #if !defined(NO_POLL_H)
 238 #include <poll.h>
 239 #elif !defined(NO_SYS_POLL_H)
 240 #include <sys/poll.h>
 241 #else
 242 /* Pull the compat stuff */
 243 #include <poll.h>
 244 #endif
 245 #ifdef HAVE_BSD_SYSCTL
 246 #include <sys/sysctl.h>
 247 #endif
 248
 249 /* Used by compat/win32/path-utils.h, and more */
 250 static inline int is_xplatform_dir_sep(int c)
 251 {
 252         return c == '/' || c == '\\';
 253 }
 254
 255 #if defined(__CYGWIN__)
 256 #include "compat/win32/path-utils.h"
 257 #endif
 258 #if defined(__MINGW32__)
 259 /* pull in Windows compatibility stuff */
 260 #include "compat/win32/path-utils.h"
 261 #include "compat/mingw.h"
 262 #elif defined(_MSC_VER)
 263 #include "compat/win32/path-utils.h"
 264 #include "compat/msvc.h"
 265 #else
 266 #include <sys/utsname.h>
 267 #include <sys/wait.h>
 268 #include <sys/resource.h>
 269 #include <sys/socket.h>
 270 #include <sys/ioctl.h>
 271 #include <termios.h>
 272 #ifndef NO_SYS_SELECT_H
 273 #include <sys/select.h>
 274 #endif
 275 #include <netinet/in.h>
 276 #include <netinet/tcp.h>
 277 #include <arpa/inet.h>
 278 #include <netdb.h>
 279 #include <pwd.h>
 280 #include <sys/un.h>
 281 #ifndef NO_INTTYPES_H
 282 #include <inttypes.h>
 283 #else
 284 #include <stdint.h>
 285 #endif
 286 #ifdef HAVE_ARC4RANDOM_LIBBSD
 287 #include <bsd/stdlib.h>
 288 #endif
 289 #ifdef HAVE_GETRANDOM
 290 #include <sys/random.h>
 291 #endif
 292 #ifdef NO_INTPTR_T
 293 /*
 294  * On I16LP32, ILP32 and LP64 "long" is the safe bet, however
 295  * on LLP86, IL33LLP64 and P64 it needs to be "long long",
 296  * while on IP16 and IP16L32 it is "int" (resp. "short")
 297  * Size needs to match (or exceed) 'sizeof(void *)'.
 298  * We can't take "long long" here as not everybody has it.
 299  */
 300 typedef long intptr_t;
 301 typedef unsigned long uintptr_t;
 302 #endif
 303 #undef _ALL_SOURCE /* AIX 5.3L defines a struct list with _ALL_SOURCE. */
 304 #include <grp.h>
 305 #define _ALL_SOURCE 1
 306 #endif
 307
 308 /* used on Mac OS X */
 309 #ifdef PRECOMPOSE_UNICODE
 310 #include "compat/precompose_utf8.h"
 311 #else
 312 static inline const char *precompose_argv_prefix(int argc, const char **argv, const char *prefix)
 313 {
 314         return prefix;
 315 }
 316 static inline const char *precompose_string_if_needed(const char *in)
 317 {
 318         return in;
 319 }
 320
 321 #define probe_utf8_pathname_composition()
 322 #endif
 323
 324 #ifdef MKDIR_WO_TRAILING_SLASH
 325 #define mkdir(a,b) compat_mkdir_wo_trailing_slash((a),(b))
 326 int compat_mkdir_wo_trailing_slash(const char*, mode_t);
 327 #endif
 328
 329 #ifdef NO_STRUCT_ITIMERVAL
 330 struct itimerval {
 331         struct timeval it_interval;
 332         struct timeval it_value;
 333 };
 334 #endif
 335
 336 #ifdef NO_SETITIMER
 337 static inline int setitimer(int which, const struct itimerval *value, struct itimerval *newvalue) {
 338         return 0; /* pretend success */
 339 }
 340 #endif
 341
 342 #ifndef NO_LIBGEN_H
 343 #include <libgen.h>
 344 #else
 345 #define basename gitbasename
 346 char *gitbasename(char *);
 347 #define dirname gitdirname
 348 char *gitdirname(char *);
 349 #endif
 350
 351 #ifndef NO_ICONV
 352 #include <iconv.h>
 353 #endif
 354
 355 #ifndef NO_OPENSSL
 356 #ifdef __APPLE__
 357 #define __AVAILABILITY_MACROS_USES_AVAILABILITY 0
 358 #include <AvailabilityMacros.h>
 359 #undef DEPRECATED_ATTRIBUTE
 360 #define DEPRECATED_ATTRIBUTE
 361 #undef __AVAILABILITY_MACROS_USES_AVAILABILITY
 362 #endif
 363 #include <openssl/ssl.h>
 364 #include <openssl/err.h>
 365 #endif
 366
 367 #ifdef HAVE_SYSINFO
 368 # include <sys/sysinfo.h>
 369 #endif
 370
 371 /* On most systems <netdb.h> would have given us this, but
 372  * not on some systems (e.g. z/OS).
 373  */
 374 #ifndef NI_MAXHOST
 375 #define NI_MAXHOST 1025
 376 #endif
 377
 378 #ifndef NI_MAXSERV
 379 #define NI_MAXSERV 32
 380 #endif
 381
 382 /* On most systems <limits.h> would have given us this, but
 383  * not on some systems (e.g. GNU/Hurd).
 384  */
 385 #ifndef PATH_MAX
 386 #define PATH_MAX 4096
 387 #endif
 388
 389 typedef uintmax_t timestamp_t;
 390 #define PRItime PRIuMAX
 391 #define parse_timestamp strtoumax
 392 #define TIME_MAX UINTMAX_MAX
 393 #define TIME_MIN 0
 394
 395 #ifndef PATH_SEP
 396 #define PATH_SEP ':'
 397 #endif
 398
 399 #ifdef HAVE_PATHS_H
 400 #include <paths.h>
 401 #endif
 402 #ifndef _PATH_DEFPATH
 403 #define _PATH_DEFPATH "/usr/local/bin:/usr/bin:/bin"
 404 #endif
 405
 406 #ifndef platform_core_config
 407 static inline int noop_core_config(const char *var UNUSED,
 408                                    const char *value UNUSED,
 409                                    void *cb UNUSED)
 410 {
 411         return 0;
 412 }
 413 #define platform_core_config noop_core_config
 414 #endif
 415
 416 int lstat_cache_aware_rmdir(const char *path);
 417 #if !defined(__MINGW32__) && !defined(_MSC_VER)
 418 #define rmdir lstat_cache_aware_rmdir
 419 #endif
 420
 421 #ifndef has_dos_drive_prefix
 422 static inline int git_has_dos_drive_prefix(const char *path)
 423 {
 424         return 0;
 425 }
 426 #define has_dos_drive_prefix git_has_dos_drive_prefix
 427 #endif
 428
 429 #ifndef skip_dos_drive_prefix
 430 static inline int git_skip_dos_drive_prefix(char **path)
 431 {
 432         return 0;
 433 }
 434 #define skip_dos_drive_prefix git_skip_dos_drive_prefix
 435 #endif
 436
 437 static inline int git_is_dir_sep(int c)
 438 {
 439         return c == '/';
 440 }
 441 #ifndef is_dir_sep
 442 #define is_dir_sep git_is_dir_sep
 443 #endif
 444
 445 #ifndef offset_1st_component
 446 static inline int git_offset_1st_component(const char *path)
 447 {
 448         return is_dir_sep(path[0]);
 449 }
 450 #define offset_1st_component git_offset_1st_component
 451 #endif
 452
 453 #ifndef is_valid_path
 454 #define is_valid_path(path) 1
 455 #endif
 456
 457 #ifndef is_path_owned_by_current_user
 458
 459 #ifdef __TANDEM
 460 #define ROOT_UID 65535
 461 #else
 462 #define ROOT_UID 0
 463 #endif
 464
 465 /*
 466  * Do not use this function when
 467  * (1) geteuid() did not say we are running as 'root', or
 468  * (2) using this function will compromise the system.
 469  *
 470  * PORTABILITY WARNING:
 471  * This code assumes uid_t is unsigned because that is what sudo does.
 472  * If your uid_t type is signed and all your ids are positive then it
 473  * should all work fine.
 474  * If your version of sudo uses negative values for uid_t or it is
 475  * buggy and return an overflowed value in SUDO_UID, then git might
 476  * fail to grant access to your repository properly or even mistakenly
 477  * grant access to someone else.
 478  * In the unlikely scenario this happened to you, and that is how you
 479  * got to this message, we would like to know about it; so sent us an
 480  * email to git@vger.kernel.org indicating which platform you are
 481  * using and which version of sudo, so we can improve this logic and
 482  * maybe provide you with a patch that would prevent this issue again
 483  * in the future.
 484  */
 485 static inline void extract_id_from_env(const char *env, uid_t *id)
 486 {
 487         const char *real_uid = getenv(env);
 488
 489         /* discard anything empty to avoid a more complex check below */
 490         if (real_uid && *real_uid) {
 491                 char *endptr = NULL;
 492                 unsigned long env_id;
 493
 494                 errno = 0;
 495                 /* silent overflow errors could trigger a bug here */
 496                 env_id = strtoul(real_uid, &endptr, 10);
 497                 if (!*endptr && !errno)
 498                         *id = env_id;
 499         }
 500 }
 501
 502 static inline int is_path_owned_by_current_uid(const char *path,
 503                                                struct strbuf *report UNUSED)
 504 {
 505         struct stat st;
 506         uid_t euid;
 507
 508         if (lstat(path, &st))
 509                 return 0;
 510
 511         euid = geteuid();
 512         if (euid == ROOT_UID)
 513         {
 514                 if (st.st_uid == ROOT_UID)
 515                         return 1;
 516                 else
 517                         extract_id_from_env("SUDO_UID", &euid);
 518         }
 519
 520         return st.st_uid == euid;
 521 }
 522
 523 #define is_path_owned_by_current_user is_path_owned_by_current_uid
 524 #endif
 525
 526 #ifndef find_last_dir_sep
 527 static inline char *git_find_last_dir_sep(const char *path)
 528 {
 529         return strrchr(path, '/');
 530 }
 531 #define find_last_dir_sep git_find_last_dir_sep
 532 #endif
 533
 534 #ifndef has_dir_sep
 535 static inline int git_has_dir_sep(const char *path)
 536 {
 537         return !!strchr(path, '/');
 538 }
 539 #define has_dir_sep(path) git_has_dir_sep(path)
 540 #endif
 541
 542 #ifndef query_user_email
 543 #define query_user_email() NULL
 544 #endif
 545
 546 #ifdef __TANDEM
 547 #include <floss.h(floss_execl,floss_execlp,floss_execv,floss_execvp)>
 548 #include <floss.h(floss_getpwuid)>
 549 #ifndef NSIG
 550 /*
 551  * NonStop NSE and NSX do not provide NSIG. SIGGUARDIAN(99) is the highest
 552  * known, by detective work using kill -l as a list is all signals
 553  * instead of signal.h where it should be.
 554  */
 555 # define NSIG 100
 556 #endif
 557 #endif
 558
 559 #if defined(__HP_cc) && (__HP_cc >= 61000)
 560 #define NORETURN __attribute__((noreturn))
 561 #define NORETURN_PTR
 562 #elif defined(__GNUC__) && !defined(NO_NORETURN)
 563 #define NORETURN __attribute__((__noreturn__))
 564 #define NORETURN_PTR __attribute__((__noreturn__))
 565 #elif defined(_MSC_VER)
 566 #define NORETURN __declspec(noreturn)
 567 #define NORETURN_PTR
 568 #else
 569 #define NORETURN
 570 #define NORETURN_PTR
 571 #ifndef __GNUC__
 572 #ifndef __attribute__
 573 #define __attribute__(x)
 574 #endif
 575 #endif
 576 #endif
 577
 578 /* The sentinel attribute is valid from gcc version 4.0 */
 579 #if defined(__GNUC__) && (__GNUC__ >= 4)
 580 #define LAST_ARG_MUST_BE_NULL __attribute__((sentinel))
 581 #else
 582 #define LAST_ARG_MUST_BE_NULL
 583 #endif
 584
 585 #define MAYBE_UNUSED __attribute__((__unused__))
 586
 587 #include "compat/bswap.h"
 588
 589 #include "wildmatch.h"
 590
 591 struct strbuf;
 592
 593 /* General helper functions */
 594 NORETURN void usage(const char *err);
 595 NORETURN void usagef(const char *err, ...) __attribute__((format (printf, 1, 2)));
 596 NORETURN void die(const char *err, ...) __attribute__((format (printf, 1, 2)));
 597 NORETURN void die_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
 598 int die_message(const char *err, ...) __attribute__((format (printf, 1, 2)));
 599 int die_message_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
 600 int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
 601 int error_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
 602 void warning(const char *err, ...) __attribute__((format (printf, 1, 2)));
 603 void warning_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
 604
 605 #ifndef NO_OPENSSL
 606 #ifdef APPLE_COMMON_CRYPTO
 607 #include "compat/apple-common-crypto.h"
 608 #else
 609 #include <openssl/evp.h>
 610 #include <openssl/hmac.h>
 611 #endif /* APPLE_COMMON_CRYPTO */
 612 #include <openssl/x509v3.h>
 613 #endif /* NO_OPENSSL */
 614
 615 #ifdef HAVE_OPENSSL_CSPRNG
 616 #include <openssl/rand.h>
 617 #endif
 618
 619 /*
 620  * Let callers be aware of the constant return value; this can help
 621  * gcc with -Wuninitialized analysis. We restrict this trick to gcc, though,
 622  * because other compilers may be confused by this.
 623  */
 624 #if defined(__GNUC__)
 625 static inline int const_error(void)
 626 {
 627         return -1;
 628 }
 629 #define error(...) (error(__VA_ARGS__), const_error())
 630 #define error_errno(...) (error_errno(__VA_ARGS__), const_error())
 631 #endif
 632
 633 typedef void (*report_fn)(const char *, va_list params);
 634
 635 void set_die_routine(NORETURN_PTR report_fn routine);
 636 report_fn get_die_message_routine(void);
 637 void set_error_routine(report_fn routine);
 638 report_fn get_error_routine(void);
 639 void set_warn_routine(report_fn routine);
 640 report_fn get_warn_routine(void);
 641 void set_die_is_recursing_routine(int (*routine)(void));
 642
 643 int starts_with(const char *str, const char *prefix);
 644 int istarts_with(const char *str, const char *prefix);
 645
 646 /*
 647  * If the string "str" begins with the string found in "prefix", return 1.
 648  * The "out" parameter is set to "str + strlen(prefix)" (i.e., to the point in
 649  * the string right after the prefix).
 650  *
 651  * Otherwise, return 0 and leave "out" untouched.
 652  *
 653  * Examples:
 654  *
 655  *   [extract branch name, fail if not a branch]
 656  *   if (!skip_prefix(ref, "refs/heads/", &branch)
 657  *      return -1;
 658  *
 659  *   [skip prefix if present, otherwise use whole string]
 660  *   skip_prefix(name, "refs/heads/", &name);
 661  */
 662 static inline int skip_prefix(const char *str, const char *prefix,
 663                               const char **out)
 664 {
 665         do {
 666                 if (!*prefix) {
 667                         *out = str;
 668                         return 1;
 669                 }
 670         } while (*str++ == *prefix++);
 671         return 0;
 672 }
 673
 674 /*
 675  * If the string "str" is the same as the string in "prefix", then the "arg"
 676  * parameter is set to the "def" parameter and 1 is returned.
 677  * If the string "str" begins with the string found in "prefix" and then a
 678  * "=" sign, then the "arg" parameter is set to "str + strlen(prefix) + 1"
 679  * (i.e., to the point in the string right after the prefix and the "=" sign),
 680  * and 1 is returned.
 681  *
 682  * Otherwise, return 0 and leave "arg" untouched.
 683  *
 684  * When we accept both a "--key" and a "--key=<val>" option, this function
 685  * can be used instead of !strcmp(arg, "--key") and then
 686  * skip_prefix(arg, "--key=", &arg) to parse such an option.
 687  */
 688 int skip_to_optional_arg_default(const char *str, const char *prefix,
 689                                  const char **arg, const char *def);
 690
 691 static inline int skip_to_optional_arg(const char *str, const char *prefix,
 692                                        const char **arg)
 693 {
 694         return skip_to_optional_arg_default(str, prefix, arg, "");
 695 }
 696
 697 /*
 698  * Like skip_prefix, but promises never to read past "len" bytes of the input
 699  * buffer, and returns the remaining number of bytes in "out" via "outlen".
 700  */
 701 static inline int skip_prefix_mem(const char *buf, size_t len,
 702                                   const char *prefix,
 703                                   const char **out, size_t *outlen)
 704 {
 705         size_t prefix_len = strlen(prefix);
 706         if (prefix_len <= len && !memcmp(buf, prefix, prefix_len)) {
 707                 *out = buf + prefix_len;
 708                 *outlen = len - prefix_len;
 709                 return 1;
 710         }
 711         return 0;
 712 }
 713
 714 /*
 715  * If buf ends with suffix, return 1 and subtract the length of the suffix
 716  * from *len. Otherwise, return 0 and leave *len untouched.
 717  */
 718 static inline int strip_suffix_mem(const char *buf, size_t *len,
 719                                    const char *suffix)
 720 {
 721         size_t suflen = strlen(suffix);
 722         if (*len < suflen || memcmp(buf + (*len - suflen), suffix, suflen))
 723                 return 0;
 724         *len -= suflen;
 725         return 1;
 726 }
 727
 728 /*
 729  * If str ends with suffix, return 1 and set *len to the size of the string
 730  * without the suffix. Otherwise, return 0 and set *len to the size of the
 731  * string.
 732  *
 733  * Note that we do _not_ NUL-terminate str to the new length.
 734  */
 735 static inline int strip_suffix(const char *str, const char *suffix, size_t *len)
 736 {
 737         *len = strlen(str);
 738         return strip_suffix_mem(str, len, suffix);
 739 }
 740
 741 static inline int ends_with(const char *str, const char *suffix)
 742 {
 743         size_t len;
 744         return strip_suffix(str, suffix, &len);
 745 }
 746
 747 #define SWAP(a, b) do {                                         \
 748         void *_swap_a_ptr = &(a);                               \
 749         void *_swap_b_ptr = &(b);                               \
 750         unsigned char _swap_buffer[sizeof(a)];                  \
 751         memcpy(_swap_buffer, _swap_a_ptr, sizeof(a));           \
 752         memcpy(_swap_a_ptr, _swap_b_ptr, sizeof(a) +            \
 753                BUILD_ASSERT_OR_ZERO(sizeof(a) == sizeof(b)));   \
 754         memcpy(_swap_b_ptr, _swap_buffer, sizeof(a));           \
 755 } while (0)
 756
 757 #if defined(NO_MMAP) || defined(USE_WIN32_MMAP)
 758
 759 #ifndef PROT_READ
 760 #define PROT_READ 1
 761 #define PROT_WRITE 2
 762 #define MAP_PRIVATE 1
 763 #endif
 764
 765 #define mmap git_mmap
 766 #define munmap git_munmap
 767 void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset);
 768 int git_munmap(void *start, size_t length);
 769
 770 #else /* NO_MMAP || USE_WIN32_MMAP */
 771
 772 #include <sys/mman.h>
 773
 774 #endif /* NO_MMAP || USE_WIN32_MMAP */
 775
 776 #ifdef NO_MMAP
 777
 778 /* This value must be multiple of (pagesize * 2) */
 779 #define DEFAULT_PACKED_GIT_WINDOW_SIZE (1 * 1024 * 1024)
 780
 781 #else /* NO_MMAP */
 782
 783 /* This value must be multiple of (pagesize * 2) */
 784 #define DEFAULT_PACKED_GIT_WINDOW_SIZE \
 785         (sizeof(void*) >= 8 \
 786                 ?  1 * 1024 * 1024 * 1024 \
 787                 : 32 * 1024 * 1024)
 788
 789 #endif /* NO_MMAP */
 790
 791 #ifndef MAP_FAILED
 792 #define MAP_FAILED ((void *)-1)
 793 #endif
 794
 795 #ifdef NO_ST_BLOCKS_IN_STRUCT_STAT
 796 #define on_disk_bytes(st) ((st).st_size)
 797 #else
 798 #define on_disk_bytes(st) ((st).st_blocks * 512)
 799 #endif
 800
 801 #ifdef NEEDS_MODE_TRANSLATION
 802 #undef S_IFMT
 803 #undef S_IFREG
 804 #undef S_IFDIR
 805 #undef S_IFLNK
 806 #undef S_IFBLK
 807 #undef S_IFCHR
 808 #undef S_IFIFO
 809 #undef S_IFSOCK
 810 #define S_IFMT   0170000
 811 #define S_IFREG  0100000
 812 #define S_IFDIR  0040000
 813 #define S_IFLNK  0120000
 814 #define S_IFBLK  0060000
 815 #define S_IFCHR  0020000
 816 #define S_IFIFO  0010000
 817 #define S_IFSOCK 0140000
 818 #ifdef stat
 819 #undef stat
 820 #endif
 821 #define stat(path, buf) git_stat(path, buf)
 822 int git_stat(const char *, struct stat *);
 823 #ifdef fstat
 824 #undef fstat
 825 #endif
 826 #define fstat(fd, buf) git_fstat(fd, buf)
 827 int git_fstat(int, struct stat *);
 828 #ifdef lstat
 829 #undef lstat
 830 #endif
 831 #define lstat(path, buf) git_lstat(path, buf)
 832 int git_lstat(const char *, struct stat *);
 833 #endif
 834
 835 #define DEFAULT_PACKED_GIT_LIMIT \
 836         ((1024L * 1024L) * (size_t)(sizeof(void*) >= 8 ? (32 * 1024L * 1024L) : 256))
 837
 838 #ifdef NO_PREAD
 839 #define pread git_pread
 840 ssize_t git_pread(int fd, void *buf, size_t count, off_t offset);
 841 #endif
 842 /*
 843  * Forward decl that will remind us if its twin in cache.h changes.
 844  * This function is used in compat/pread.c.  But we can't include
 845  * cache.h there.
 846  */
 847 ssize_t read_in_full(int fd, void *buf, size_t count);
 848
 849 #ifdef NO_SETENV
 850 #define setenv gitsetenv
 851 int gitsetenv(const char *, const char *, int);
 852 #endif
 853
 854 #ifdef NO_MKDTEMP
 855 #define mkdtemp gitmkdtemp
 856 char *gitmkdtemp(char *);
 857 #endif
 858
 859 #ifdef NO_UNSETENV
 860 #define unsetenv gitunsetenv
 861 int gitunsetenv(const char *);
 862 #endif
 863
 864 #ifdef NO_STRCASESTR
 865 #define strcasestr gitstrcasestr
 866 char *gitstrcasestr(const char *haystack, const char *needle);
 867 #endif
 868
 869 #ifdef NO_STRLCPY
 870 #define strlcpy gitstrlcpy
 871 size_t gitstrlcpy(char *, const char *, size_t);
 872 #endif
 873
 874 #ifdef NO_STRTOUMAX
 875 #define strtoumax gitstrtoumax
 876 uintmax_t gitstrtoumax(const char *, char **, int);
 877 #define strtoimax gitstrtoimax
 878 intmax_t gitstrtoimax(const char *, char **, int);
 879 #endif
 880
 881 #ifdef NO_HSTRERROR
 882 #define hstrerror githstrerror
 883 const char *githstrerror(int herror);
 884 #endif
 885
 886 #ifdef NO_MEMMEM
 887 #define memmem gitmemmem
 888 void *gitmemmem(const void *haystack, size_t haystacklen,
 889                 const void *needle, size_t needlelen);
 890 #endif
 891
 892 #ifdef OVERRIDE_STRDUP
 893 #ifdef strdup
 894 #undef strdup
 895 #endif
 896 #define strdup gitstrdup
 897 char *gitstrdup(const char *s);
 898 #endif
 899
 900 #ifdef NO_GETPAGESIZE
 901 #define getpagesize() sysconf(_SC_PAGESIZE)
 902 #endif
 903
 904 #ifndef O_CLOEXEC
 905 #define O_CLOEXEC 0
 906 #endif
 907
 908 #ifdef FREAD_READS_DIRECTORIES
 909 # if !defined(SUPPRESS_FOPEN_REDEFINITION)
 910 #  ifdef fopen
 911 #   undef fopen
 912 #  endif
 913 #  define fopen(a,b) git_fopen(a,b)
 914 # endif
 915 FILE *git_fopen(const char*, const char*);
 916 #endif
 917
 918 #ifdef SNPRINTF_RETURNS_BOGUS
 919 #ifdef snprintf
 920 #undef snprintf
 921 #endif
 922 #define snprintf git_snprintf
 923 int git_snprintf(char *str, size_t maxsize,
 924                  const char *format, ...);
 925 #ifdef vsnprintf
 926 #undef vsnprintf
 927 #endif
 928 #define vsnprintf git_vsnprintf
 929 int git_vsnprintf(char *str, size_t maxsize,
 930                   const char *format, va_list ap);
 931 #endif
 932
 933 #ifdef OPEN_RETURNS_EINTR
 934 #undef open
 935 #define open git_open_with_retry
 936 int git_open_with_retry(const char *path, int flag, ...);
 937 #endif
 938
 939 #ifdef __GLIBC_PREREQ
 940 #if __GLIBC_PREREQ(2, 1)
 941 #define HAVE_STRCHRNUL
 942 #endif
 943 #endif
 944
 945 #ifndef HAVE_STRCHRNUL
 946 #define strchrnul gitstrchrnul
 947 static inline char *gitstrchrnul(const char *s, int c)
 948 {
 949         while (*s && *s != c)
 950                 s++;
 951         return (char *)s;
 952 }
 953 #endif
 954
 955 #ifdef NO_INET_PTON
 956 int inet_pton(int af, const char *src, void *dst);
 957 #endif
 958
 959 #ifdef NO_INET_NTOP
 960 const char *inet_ntop(int af, const void *src, char *dst, size_t size);
 961 #endif
 962
 963 #ifdef NO_PTHREADS
 964 #define atexit git_atexit
 965 int git_atexit(void (*handler)(void));
 966 #endif
 967
 968 static inline size_t st_add(size_t a, size_t b)
 969 {
 970         if (unsigned_add_overflows(a, b))
 971                 die("size_t overflow: %"PRIuMAX" + %"PRIuMAX,
 972                     (uintmax_t)a, (uintmax_t)b);
 973         return a + b;
 974 }
 975 #define st_add3(a,b,c)   st_add(st_add((a),(b)),(c))
 976 #define st_add4(a,b,c,d) st_add(st_add3((a),(b),(c)),(d))
 977
 978 static inline size_t st_mult(size_t a, size_t b)
 979 {
 980         if (unsigned_mult_overflows(a, b))
 981                 die("size_t overflow: %"PRIuMAX" * %"PRIuMAX,
 982                     (uintmax_t)a, (uintmax_t)b);
 983         return a * b;
 984 }
 985
 986 static inline size_t st_sub(size_t a, size_t b)
 987 {
 988         if (a < b)
 989                 die("size_t underflow: %"PRIuMAX" - %"PRIuMAX,
 990                     (uintmax_t)a, (uintmax_t)b);
 991         return a - b;
 992 }
 993
 994 static inline size_t st_left_shift(size_t a, unsigned shift)
 995 {
 996         if (unsigned_left_shift_overflows(a, shift))
 997                 die("size_t overflow: %"PRIuMAX" << %u",
 998                     (uintmax_t)a, shift);
 999         return a << shift;
1000 }
1001
1002 static inline unsigned long cast_size_t_to_ulong(size_t a)
1003 {
1004         if (a != (unsigned long)a)
1005                 die("object too large to read on this platform: %"
1006                     PRIuMAX" is cut off to %lu",
1007                     (uintmax_t)a, (unsigned long)a);
1008         return (unsigned long)a;
1009 }
1010
1011 #ifdef HAVE_ALLOCA_H
1012 # include <alloca.h>
1013 # define xalloca(size)      (alloca(size))
1014 # define xalloca_free(p)    do {} while (0)
1015 #else
1016 # define xalloca(size)      (xmalloc(size))
1017 # define xalloca_free(p)    (free(p))
1018 #endif
1019 char *xstrdup(const char *str);
1020 void *xmalloc(size_t size);
1021 void *xmallocz(size_t size);
1022 void *xmallocz_gently(size_t size);
1023 void *xmemdupz(const void *data, size_t len);
1024 char *xstrndup(const char *str, size_t len);
1025 void *xrealloc(void *ptr, size_t size);
1026 void *xcalloc(size_t nmemb, size_t size);
1027 void xsetenv(const char *name, const char *value, int overwrite);
1028 void *xmmap(void *start, size_t length, int prot, int flags, int fd, off_t offset);
1029 const char *mmap_os_err(void);
1030 void *xmmap_gently(void *start, size_t length, int prot, int flags, int fd, off_t offset);
1031 int xopen(const char *path, int flags, ...);
1032 ssize_t xread(int fd, void *buf, size_t len);
1033 ssize_t xwrite(int fd, const void *buf, size_t len);
1034 ssize_t xpread(int fd, void *buf, size_t len, off_t offset);
1035 int xdup(int fd);
1036 FILE *xfopen(const char *path, const char *mode);
1037 FILE *xfdopen(int fd, const char *mode);
1038 int xmkstemp(char *temp_filename);
1039 int xmkstemp_mode(char *temp_filename, int mode);
1040 char *xgetcwd(void);
1041 FILE *fopen_for_writing(const char *path);
1042 FILE *fopen_or_warn(const char *path, const char *mode);
1043
1044 /*
1045  * Like strncmp, but only return zero if s is NUL-terminated and exactly len
1046  * characters long.  If it is not, consider it greater than t.
1047  */
1048 int xstrncmpz(const char *s, const char *t, size_t len);
1049
1050 /*
1051  * FREE_AND_NULL(ptr) is like free(ptr) followed by ptr = NULL. Note
1052  * that ptr is used twice, so don't pass e.g. ptr++.
1053  */
1054 #define FREE_AND_NULL(p) do { free(p); (p) = NULL; } while (0)
1055
1056 #define ALLOC_ARRAY(x, alloc) (x) = xmalloc(st_mult(sizeof(*(x)), (alloc)))
1057 #define CALLOC_ARRAY(x, alloc) (x) = xcalloc((alloc), sizeof(*(x)))
1058 #define REALLOC_ARRAY(x, alloc) (x) = xrealloc((x), st_mult(sizeof(*(x)), (alloc)))
1059
1060 #define COPY_ARRAY(dst, src, n) copy_array((dst), (src), (n), sizeof(*(dst)) + \
1061         BUILD_ASSERT_OR_ZERO(sizeof(*(dst)) == sizeof(*(src))))
1062 static inline void copy_array(void *dst, const void *src, size_t n, size_t size)
1063 {
1064         if (n)
1065                 memcpy(dst, src, st_mult(size, n));
1066 }
1067
1068 #define MOVE_ARRAY(dst, src, n) move_array((dst), (src), (n), sizeof(*(dst)) + \
1069         BUILD_ASSERT_OR_ZERO(sizeof(*(dst)) == sizeof(*(src))))
1070 static inline void move_array(void *dst, const void *src, size_t n, size_t size)
1071 {
1072         if (n)
1073                 memmove(dst, src, st_mult(size, n));
1074 }
1075
1076 /*
1077  * These functions help you allocate structs with flex arrays, and copy
1078  * the data directly into the array. For example, if you had:
1079  *
1080  *   struct foo {
1081  *     int bar;
1082  *     char name[FLEX_ARRAY];
1083  *   };
1084  *
1085  * you can do:
1086  *
1087  *   struct foo *f;
1088  *   FLEX_ALLOC_MEM(f, name, src, len);
1089  *
1090  * to allocate a "foo" with the contents of "src" in the "name" field.
1091  * The resulting struct is automatically zero'd, and the flex-array field
1092  * is NUL-terminated (whether the incoming src buffer was or not).
1093  *
1094  * The FLEXPTR_* variants operate on structs that don't use flex-arrays,
1095  * but do want to store a pointer to some extra data in the same allocated
1096  * block. For example, if you have:
1097  *
1098  *   struct foo {
1099  *     char *name;
1100  *     int bar;
1101  *   };
1102  *
1103  * you can do:
1104  *
1105  *   struct foo *f;
1106  *   FLEXPTR_ALLOC_STR(f, name, src);
1107  *
1108  * and "name" will point to a block of memory after the struct, which will be
1109  * freed along with the struct (but the pointer can be repointed anywhere).
1110  *
1111  * The *_STR variants accept a string parameter rather than a ptr/len
1112  * combination.
1113  *
1114  * Note that these macros will evaluate the first parameter multiple
1115  * times, and it must be assignable as an lvalue.
1116  */
1117 #define FLEX_ALLOC_MEM(x, flexname, buf, len) do { \
1118         size_t flex_array_len_ = (len); \
1119         (x) = xcalloc(1, st_add3(sizeof(*(x)), flex_array_len_, 1)); \
1120         memcpy((void *)(x)->flexname, (buf), flex_array_len_); \
1121 } while (0)
1122 #define FLEXPTR_ALLOC_MEM(x, ptrname, buf, len) do { \
1123         size_t flex_array_len_ = (len); \
1124         (x) = xcalloc(1, st_add3(sizeof(*(x)), flex_array_len_, 1)); \
1125         memcpy((x) + 1, (buf), flex_array_len_); \
1126         (x)->ptrname = (void *)((x)+1); \
1127 } while(0)
1128 #define FLEX_ALLOC_STR(x, flexname, str) \
1129         FLEX_ALLOC_MEM((x), flexname, (str), strlen(str))
1130 #define FLEXPTR_ALLOC_STR(x, ptrname, str) \
1131         FLEXPTR_ALLOC_MEM((x), ptrname, (str), strlen(str))
1132
1133 static inline char *xstrdup_or_null(const char *str)
1134 {
1135         return str ? xstrdup(str) : NULL;
1136 }
1137
1138 static inline size_t xsize_t(off_t len)
1139 {
1140         if (len < 0 || (uintmax_t) len > SIZE_MAX)
1141                 die("Cannot handle files this big");
1142         return (size_t) len;
1143 }
1144
1145 __attribute__((format (printf, 3, 4)))
1146 int xsnprintf(char *dst, size_t max, const char *fmt, ...);
1147
1148 #ifndef HOST_NAME_MAX
1149 #define HOST_NAME_MAX 256
1150 #endif
1151
1152 int xgethostname(char *buf, size_t len);
1153
1154 /* in ctype.c, for kwset users */
1155 extern const unsigned char tolower_trans_tbl[256];
1156
1157 /* Sane ctype - no locale, and works with signed chars */
1158 #undef isascii
1159 #undef isspace
1160 #undef isdigit
1161 #undef isalpha
1162 #undef isalnum
1163 #undef isprint
1164 #undef islower
1165 #undef isupper
1166 #undef tolower
1167 #undef toupper
1168 #undef iscntrl
1169 #undef ispunct
1170 #undef isxdigit
1171
1172 extern const unsigned char sane_ctype[256];
1173 #define GIT_SPACE 0x01
1174 #define GIT_DIGIT 0x02
1175 #define GIT_ALPHA 0x04
1176 #define GIT_GLOB_SPECIAL 0x08
1177 #define GIT_REGEX_SPECIAL 0x10
1178 #define GIT_PATHSPEC_MAGIC 0x20
1179 #define GIT_CNTRL 0x40
1180 #define GIT_PUNCT 0x80
1181 #define sane_istest(x,mask) ((sane_ctype[(unsigned char)(x)] & (mask)) != 0)
1182 #define isascii(x) (((x) & ~0x7f) == 0)
1183 #define isspace(x) sane_istest(x,GIT_SPACE)
1184 #define isdigit(x) sane_istest(x,GIT_DIGIT)
1185 #define isalpha(x) sane_istest(x,GIT_ALPHA)
1186 #define isalnum(x) sane_istest(x,GIT_ALPHA | GIT_DIGIT)
1187 #define isprint(x) ((x) >= 0x20 && (x) <= 0x7e)
1188 #define islower(x) sane_iscase(x, 1)
1189 #define isupper(x) sane_iscase(x, 0)
1190 #define is_glob_special(x) sane_istest(x,GIT_GLOB_SPECIAL)
1191 #define is_regex_special(x) sane_istest(x,GIT_GLOB_SPECIAL | GIT_REGEX_SPECIAL)
1192 #define iscntrl(x) (sane_istest(x,GIT_CNTRL))
1193 #define ispunct(x) sane_istest(x, GIT_PUNCT | GIT_REGEX_SPECIAL | \
1194                 GIT_GLOB_SPECIAL | GIT_PATHSPEC_MAGIC)
1195 #define isxdigit(x) (hexval_table[(unsigned char)(x)] != -1)
1196 #define tolower(x) sane_case((unsigned char)(x), 0x20)
1197 #define toupper(x) sane_case((unsigned char)(x), 0)
1198 #define is_pathspec_magic(x) sane_istest(x,GIT_PATHSPEC_MAGIC)
1199
1200 static inline int sane_case(int x, int high)
1201 {
1202         if (sane_istest(x, GIT_ALPHA))
1203                 x = (x & ~0x20) | high;
1204         return x;
1205 }
1206
1207 static inline int sane_iscase(int x, int is_lower)
1208 {
1209         if (!sane_istest(x, GIT_ALPHA))
1210                 return 0;
1211
1212         if (is_lower)
1213                 return (x & 0x20) != 0;
1214         else
1215                 return (x & 0x20) == 0;
1216 }
1217
1218 /*
1219  * Like skip_prefix, but compare case-insensitively. Note that the comparison
1220  * is done via tolower(), so it is strictly ASCII (no multi-byte characters or
1221  * locale-specific conversions).
1222  */
1223 static inline int skip_iprefix(const char *str, const char *prefix,
1224                                const char **out)
1225 {
1226         do {
1227                 if (!*prefix) {
1228                         *out = str;
1229                         return 1;
1230                 }
1231         } while (tolower(*str++) == tolower(*prefix++));
1232         return 0;
1233 }
1234
1235 static inline int strtoul_ui(char const *s, int base, unsigned int *result)
1236 {
1237         unsigned long ul;
1238         char *p;
1239
1240         errno = 0;
1241         /* negative values would be accepted by strtoul */
1242         if (strchr(s, '-'))
1243                 return -1;
1244         ul = strtoul(s, &p, base);
1245         if (errno || *p || p == s || (unsigned int) ul != ul)
1246                 return -1;
1247         *result = ul;
1248         return 0;
1249 }
1250
1251 static inline int strtol_i(char const *s, int base, int *result)
1252 {
1253         long ul;
1254         char *p;
1255
1256         errno = 0;
1257         ul = strtol(s, &p, base);
1258         if (errno || *p || p == s || (int) ul != ul)
1259                 return -1;
1260         *result = ul;
1261         return 0;
1262 }
1263
1264 void git_stable_qsort(void *base, size_t nmemb, size_t size,
1265                       int(*compar)(const void *, const void *));
1266 #ifdef INTERNAL_QSORT
1267 #define qsort git_stable_qsort
1268 #endif
1269
1270 #define QSORT(base, n, compar) sane_qsort((base), (n), sizeof(*(base)), compar)
1271 static inline void sane_qsort(void *base, size_t nmemb, size_t size,
1272                               int(*compar)(const void *, const void *))
1273 {
1274         if (nmemb > 1)
1275                 qsort(base, nmemb, size, compar);
1276 }
1277
1278 #define STABLE_QSORT(base, n, compar) \
1279         git_stable_qsort((base), (n), sizeof(*(base)), compar)
1280
1281 #ifndef HAVE_ISO_QSORT_S
1282 int git_qsort_s(void *base, size_t nmemb, size_t size,
1283                 int (*compar)(const void *, const void *, void *), void *ctx);
1284 #define qsort_s git_qsort_s
1285 #endif
1286
1287 #define QSORT_S(base, n, compar, ctx) do {                      \
1288         if (qsort_s((base), (n), sizeof(*(base)), compar, ctx)) \
1289                 BUG("qsort_s() failed");                        \
1290 } while (0)
1291
1292 #ifndef REG_STARTEND
1293 #error "Git requires REG_STARTEND support. Compile with NO_REGEX=NeedsStartEnd"
1294 #endif
1295
1296 static inline int regexec_buf(const regex_t *preg, const char *buf, size_t size,
1297                               size_t nmatch, regmatch_t pmatch[], int eflags)
1298 {
1299         assert(nmatch > 0 && pmatch);
1300         pmatch[0].rm_so = 0;
1301         pmatch[0].rm_eo = size;
1302         return regexec(preg, buf, nmatch, pmatch, eflags | REG_STARTEND);
1303 }
1304
1305 #ifndef DIR_HAS_BSD_GROUP_SEMANTICS
1306 # define FORCE_DIR_SET_GID S_ISGID
1307 #else
1308 # define FORCE_DIR_SET_GID 0
1309 #endif
1310
1311 #ifdef NO_NSEC
1312 #undef USE_NSEC
1313 #define ST_CTIME_NSEC(st) 0
1314 #define ST_MTIME_NSEC(st) 0
1315 #else
1316 #ifdef USE_ST_TIMESPEC
1317 #define ST_CTIME_NSEC(st) ((unsigned int)((st).st_ctimespec.tv_nsec))
1318 #define ST_MTIME_NSEC(st) ((unsigned int)((st).st_mtimespec.tv_nsec))
1319 #else
1320 #define ST_CTIME_NSEC(st) ((unsigned int)((st).st_ctim.tv_nsec))
1321 #define ST_MTIME_NSEC(st) ((unsigned int)((st).st_mtim.tv_nsec))
1322 #endif
1323 #endif
1324
1325 #ifdef UNRELIABLE_FSTAT
1326 #define fstat_is_reliable() 0
1327 #else
1328 #define fstat_is_reliable() 1
1329 #endif
1330
1331 #ifndef va_copy
1332 /*
1333  * Since an obvious implementation of va_list would be to make it a
1334  * pointer into the stack frame, a simple assignment will work on
1335  * many systems.  But let's try to be more portable.
1336  */
1337 #ifdef __va_copy
1338 #define va_copy(dst, src) __va_copy(dst, src)
1339 #else
1340 #define va_copy(dst, src) ((dst) = (src))
1341 #endif
1342 #endif
1343
1344 /* usage.c: only to be used for testing BUG() implementation (see test-tool) */
1345 extern int BUG_exit_code;
1346
1347 /* usage.c: if bug() is called we should have a BUG_if_bug() afterwards */
1348 extern int bug_called_must_BUG;
1349
1350 __attribute__((format (printf, 3, 4))) NORETURN
1351 void BUG_fl(const char *file, int line, const char *fmt, ...);
1352 #define BUG(...) BUG_fl(__FILE__, __LINE__, __VA_ARGS__)
1353 __attribute__((format (printf, 3, 4)))
1354 void bug_fl(const char *file, int line, const char *fmt, ...);
1355 #define bug(...) bug_fl(__FILE__, __LINE__, __VA_ARGS__)
1356 #define BUG_if_bug(...) do { \
1357         if (bug_called_must_BUG) \
1358                 BUG_fl(__FILE__, __LINE__, __VA_ARGS__); \
1359 } while (0)
1360
1361 #ifndef FSYNC_METHOD_DEFAULT
1362 #ifdef __APPLE__
1363 #define FSYNC_METHOD_DEFAULT FSYNC_METHOD_WRITEOUT_ONLY
1364 #else
1365 #define FSYNC_METHOD_DEFAULT FSYNC_METHOD_FSYNC
1366 #endif
1367 #endif
1368
1369 enum fsync_action {
1370         FSYNC_WRITEOUT_ONLY,
1371         FSYNC_HARDWARE_FLUSH
1372 };
1373
1374 /*
1375  * Issues an fsync against the specified file according to the specified mode.
1376  *
1377  * FSYNC_WRITEOUT_ONLY attempts to use interfaces available on some operating
1378  * systems to flush the OS cache without issuing a flush command to the storage
1379  * controller. If those interfaces are unavailable, the function fails with
1380  * ENOSYS.
1381  *
1382  * FSYNC_HARDWARE_FLUSH does an OS writeout and hardware flush to ensure that
1383  * changes are durable. It is not expected to fail.
1384  */
1385 int git_fsync(int fd, enum fsync_action action);
1386
1387 /*
1388  * Writes out trace statistics for fsync using the trace2 API.
1389  */
1390 void trace_git_fsync_stats(void);
1391
1392 /*
1393  * Preserves errno, prints a message, but gives no warning for ENOENT.
1394  * Returns 0 on success, which includes trying to unlink an object that does
1395  * not exist.
1396  */
1397 int unlink_or_warn(const char *path);
1398  /*
1399   * Tries to unlink file.  Returns 0 if unlink succeeded
1400   * or the file already didn't exist.  Returns -1 and
1401   * appends a message to err suitable for
1402   * 'error("%s", err->buf)' on error.
1403   */
1404 int unlink_or_msg(const char *file, struct strbuf *err);
1405 /*
1406  * Preserves errno, prints a message, but gives no warning for ENOENT.
1407  * Returns 0 on success, which includes trying to remove a directory that does
1408  * not exist.
1409  */
1410 int rmdir_or_warn(const char *path);
1411 /*
1412  * Calls the correct function out of {unlink,rmdir}_or_warn based on
1413  * the supplied file mode.
1414  */
1415 int remove_or_warn(unsigned int mode, const char *path);
1416
1417 /*
1418  * Call access(2), but warn for any error except "missing file"
1419  * (ENOENT or ENOTDIR).
1420  */
1421 #define ACCESS_EACCES_OK (1U << 0)
1422 int access_or_warn(const char *path, int mode, unsigned flag);
1423 int access_or_die(const char *path, int mode, unsigned flag);
1424
1425 /* Warn on an inaccessible file if errno indicates this is an error */
1426 int warn_on_fopen_errors(const char *path);
1427
1428 /*
1429  * Open with O_NOFOLLOW, or equivalent. Note that the fallback equivalent
1430  * may be racy. Do not use this as protection against an attacker who can
1431  * simultaneously create paths.
1432  */
1433 int open_nofollow(const char *path, int flags);
1434
1435 #ifndef SHELL_PATH
1436 # define SHELL_PATH "/bin/sh"
1437 #endif
1438
1439 #ifndef _POSIX_THREAD_SAFE_FUNCTIONS
1440 static inline void flockfile(FILE *fh)
1441 {
1442         ; /* nothing */
1443 }
1444 static inline void funlockfile(FILE *fh)
1445 {
1446         ; /* nothing */
1447 }
1448 #define getc_unlocked(fh) getc(fh)
1449 #endif
1450
1451 #ifdef FILENO_IS_A_MACRO
1452 int git_fileno(FILE *stream);
1453 # ifndef COMPAT_CODE_FILENO
1454 #  undef fileno
1455 #  define fileno(p) git_fileno(p)
1456 # endif
1457 #endif
1458
1459 #ifdef NEED_ACCESS_ROOT_HANDLER
1460 int git_access(const char *path, int mode);
1461 # ifndef COMPAT_CODE_ACCESS
1462 #  ifdef access
1463 #  undef access
1464 #  endif
1465 #  define access(path, mode) git_access(path, mode)
1466 # endif
1467 #endif
1468
1469 /*
1470  * Our code often opens a path to an optional file, to work on its
1471  * contents when we can successfully open it.  We can ignore a failure
1472  * to open if such an optional file does not exist, but we do want to
1473  * report a failure in opening for other reasons (e.g. we got an I/O
1474  * error, or the file is there, but we lack the permission to open).
1475  *
1476  * Call this function after seeing an error from open() or fopen() to
1477  * see if the errno indicates a missing file that we can safely ignore.
1478  */
1479 static inline int is_missing_file_error(int errno_)
1480 {
1481         return (errno_ == ENOENT || errno_ == ENOTDIR);
1482 }
1483
1484 int cmd_main(int, const char **);
1485
1486 /*
1487  * Intercept all calls to exit() and route them to trace2 to
1488  * optionally emit a message before calling the real exit().
1489  */
1490 int common_exit(const char *file, int line, int code);
1491 #define exit(code) exit(common_exit(__FILE__, __LINE__, (code)))
1492
1493 /*
1494  * You can mark a stack variable with UNLEAK(var) to avoid it being
1495  * reported as a leak by tools like LSAN or valgrind. The argument
1496  * should generally be the variable itself (not its address and not what
1497  * it points to). It's safe to use this on pointers which may already
1498  * have been freed, or on pointers which may still be in use.
1499  *
1500  * Use this _only_ for a variable that leaks by going out of scope at
1501  * program exit (so only from cmd_* functions or their direct helpers).
1502  * Normal functions, especially those which may be called multiple
1503  * times, should actually free their memory. This is only meant as
1504  * an annotation, and does nothing in non-leak-checking builds.
1505  */
1506 #ifdef SUPPRESS_ANNOTATED_LEAKS
1507 void unleak_memory(const void *ptr, size_t len);
1508 #define UNLEAK(var) unleak_memory(&(var), sizeof(var))
1509 #else
1510 #define UNLEAK(var) do {} while (0)
1511 #endif
1512
1513 #define z_const
1514 #include <zlib.h>
1515
1516 #if ZLIB_VERNUM < 0x1290
1517 /*
1518  * This is uncompress2, which is only available in zlib >= 1.2.9
1519  * (released as of early 2017). See compat/zlib-uncompress2.c.
1520  */
1521 int uncompress2(Bytef *dest, uLongf *destLen, const Bytef *source,
1522                 uLong *sourceLen);
1523 #endif
1524
1525 /*
1526  * This include must come after system headers, since it introduces macros that
1527  * replace system names.
1528  */
1529 #include "banned.h"
1530
1531 /*
1532  * container_of - Get the address of an object containing a field.
1533  *
1534  * @ptr: pointer to the field.
1535  * @type: type of the object.
1536  * @member: name of the field within the object.
1537  */
1538 #define container_of(ptr, type, member) \
1539         ((type *) ((char *)(ptr) - offsetof(type, member)))
1540
1541 /*
1542  * helper function for `container_of_or_null' to avoid multiple
1543  * evaluation of @ptr
1544  */
1545 static inline void *container_of_or_null_offset(void *ptr, size_t offset)
1546 {
1547         return ptr ? (char *)ptr - offset : NULL;
1548 }
1549
1550 /*
1551  * like `container_of', but allows returned value to be NULL
1552  */
1553 #define container_of_or_null(ptr, type, member) \
1554         (type *)container_of_or_null_offset(ptr, offsetof(type, member))
1555
1556 /*
1557  * like offsetof(), but takes a pointer to a variable of type which
1558  * contains @member, instead of a specified type.
1559  * @ptr is subject to multiple evaluation since we can't rely on __typeof__
1560  * everywhere.
1561  */
1562 #if defined(__GNUC__) /* clang sets this, too */
1563 #define OFFSETOF_VAR(ptr, member) offsetof(__typeof__(*ptr), member)
1564 #else /* !__GNUC__ */
1565 #define OFFSETOF_VAR(ptr, member) \
1566         ((uintptr_t)&(ptr)->member - (uintptr_t)(ptr))
1567 #endif /* !__GNUC__ */
1568
1569 void sleep_millisec(int millisec);
1570
1571 /*
1572  * Generate len bytes from the system cryptographically secure PRNG.
1573  * Returns 0 on success and -1 on error, setting errno.  The inability to
1574  * satisfy the full request is an error.
1575  */
1576 int csprng_bytes(void *buf, size_t len);
1577
1578 #endif