git-compat-util.h

   1 #ifndef GIT_COMPAT_UTIL_H
   2 #define GIT_COMPAT_UTIL_H
   3
   4 #ifdef USE_MSVC_CRTDBG
   5 /*
   6  * For these to work they must appear very early in each
   7  * file -- before most of the standard header files.
   8  */
   9 #include <stdlib.h>
  10 #include <crtdbg.h>
  11 #endif
  12
  13 #define _FILE_OFFSET_BITS 64
  14
  15
  16 /* Derived from Linux "Features Test Macro" header
  17  * Convenience macros to test the versions of gcc (or
  18  * a compatible compiler).
  19  * Use them like this:
  20  *  #if GIT_GNUC_PREREQ (2,8)
  21  *   ... code requiring gcc 2.8 or later ...
  22  *  #endif
  23 */
  24 #if defined(__GNUC__) && defined(__GNUC_MINOR__)
  25 # define GIT_GNUC_PREREQ(maj, min) \
  26         ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
  27 #else
  28  #define GIT_GNUC_PREREQ(maj, min) 0
  29 #endif
  30
  31
  32 #ifndef FLEX_ARRAY
  33 /*
  34  * See if our compiler is known to support flexible array members.
  35  */
  36 #if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) && (!defined(__SUNPRO_C) || (__SUNPRO_C > 0x580))
  37 # define FLEX_ARRAY /* empty */
  38 #elif defined(__GNUC__)
  39 # if (__GNUC__ >= 3)
  40 #  define FLEX_ARRAY /* empty */
  41 # else
  42 #  define FLEX_ARRAY 0 /* older GNU extension */
  43 # endif
  44 #endif
  45
  46 /*
  47  * Otherwise, default to safer but a bit wasteful traditional style
  48  */
  49 #ifndef FLEX_ARRAY
  50 # define FLEX_ARRAY 1
  51 #endif
  52 #endif
  53
  54
  55 /*
  56  * BUILD_ASSERT_OR_ZERO - assert a build-time dependency, as an expression.
  57  * @cond: the compile-time condition which must be true.
  58  *
  59  * Your compile will fail if the condition isn't true, or can't be evaluated
  60  * by the compiler.  This can be used in an expression: its value is "0".
  61  *
  62  * Example:
  63  *      #define foo_to_char(foo)                                        \
  64  *               ((char *)(foo)                                         \
  65  *                + BUILD_ASSERT_OR_ZERO(offsetof(struct foo, string) == 0))
  66  */
  67 #define BUILD_ASSERT_OR_ZERO(cond) \
  68         (sizeof(char [1 - 2*!(cond)]) - 1)
  69
  70 #if GIT_GNUC_PREREQ(3, 1)
  71  /* &arr[0] degrades to a pointer: a different type from an array */
  72 # define BARF_UNLESS_AN_ARRAY(arr)                                              \
  73         BUILD_ASSERT_OR_ZERO(!__builtin_types_compatible_p(__typeof__(arr), \
  74                                                            __typeof__(&(arr)[0])))
  75 #else
  76 # define BARF_UNLESS_AN_ARRAY(arr) 0
  77 #endif
  78 /*
  79  * ARRAY_SIZE - get the number of elements in a visible array
  80  * @x: the array whose size you want.
  81  *
  82  * This does not work on pointers, or arrays declared as [], or
  83  * function parameters.  With correct compiler support, such usage
  84  * will cause a build error (see the build_assert_or_zero macro).
  85  */
  86 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]) + BARF_UNLESS_AN_ARRAY(x))
  87
  88 #define bitsizeof(x)  (CHAR_BIT * sizeof(x))
  89
  90 #define maximum_signed_value_of_type(a) \
  91     (INTMAX_MAX >> (bitsizeof(intmax_t) - bitsizeof(a)))
  92
  93 #define maximum_unsigned_value_of_type(a) \
  94     (UINTMAX_MAX >> (bitsizeof(uintmax_t) - bitsizeof(a)))
  95
  96 /*
  97  * Signed integer overflow is undefined in C, so here's a helper macro
  98  * to detect if the sum of two integers will overflow.
  99  *
 100  * Requires: a >= 0, typeof(a) equals typeof(b)
 101  */
 102 #define signed_add_overflows(a, b) \
 103     ((b) > maximum_signed_value_of_type(a) - (a))
 104
 105 #define unsigned_add_overflows(a, b) \
 106     ((b) > maximum_unsigned_value_of_type(a) - (a))
 107
 108 /*
 109  * Returns true if the multiplication of "a" and "b" will
 110  * overflow. The types of "a" and "b" must match and must be unsigned.
 111  * Note that this macro evaluates "a" twice!
 112  */
 113 #define unsigned_mult_overflows(a, b) \
 114     ((a) && (b) > maximum_unsigned_value_of_type(a) / (a))
 115
 116 #ifdef __GNUC__
 117 #define TYPEOF(x) (__typeof__(x))
 118 #else
 119 #define TYPEOF(x)
 120 #endif
 121
 122 #define MSB(x, bits) ((x) & TYPEOF(x)(~0ULL << (bitsizeof(x) - (bits))))
 123 #define HAS_MULTI_BITS(i)  ((i) & ((i) - 1))  /* checks if an integer has more than 1 bit set */
 124
 125 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
 126
 127 /* Approximation of the length of the decimal representation of this type. */
 128 #define decimal_length(x)       ((int)(sizeof(x) * 2.56 + 0.5) + 1)
 129
 130 #ifdef __MINGW64__
 131 #define _POSIX_C_SOURCE 1
 132 #elif defined(__sun__)
 133  /*
 134   * On Solaris, when _XOPEN_EXTENDED is set, its header file
 135   * forces the programs to be XPG4v2, defeating any _XOPEN_SOURCE
 136   * setting to say we are XPG5 or XPG6.  Also on Solaris,
 137   * XPG6 programs must be compiled with a c99 compiler, while
 138   * non XPG6 programs must be compiled with a pre-c99 compiler.
 139   */
 140 # if __STDC_VERSION__ - 0 >= 199901L
 141 # define _XOPEN_SOURCE 600
 142 # else
 143 # define _XOPEN_SOURCE 500
 144 # endif
 145 #elif !defined(__APPLE__) && !defined(__FreeBSD__) && !defined(__USLC__) && \
 146       !defined(_M_UNIX) && !defined(__sgi) && !defined(__DragonFly__) && \
 147       !defined(__TANDEM) && !defined(__QNX__) && !defined(__MirBSD__) && \
 148       !defined(__CYGWIN__)
 149 #define _XOPEN_SOURCE 600 /* glibc2 and AIX 5.3L need 500, OpenBSD needs 600 for S_ISLNK() */
 150 #define _XOPEN_SOURCE_EXTENDED 1 /* AIX 5.3L needs this */
 151 #endif
 152 #define _ALL_SOURCE 1
 153 #define _GNU_SOURCE 1
 154 #define _BSD_SOURCE 1
 155 #define _DEFAULT_SOURCE 1
 156 #define _NETBSD_SOURCE 1
 157 #define _SGI_SOURCE 1
 158
 159 #if defined(WIN32) && !defined(__CYGWIN__) /* Both MinGW and MSVC */
 160 # if !defined(_WIN32_WINNT)
 161 #  define _WIN32_WINNT 0x0600
 162 # endif
 163 #define WIN32_LEAN_AND_MEAN  /* stops windows.h including winsock.h */
 164 #include <winsock2.h>
 165 #ifndef NO_UNIX_SOCKETS
 166 #include <afunix.h>
 167 #endif
 168 #include <windows.h>
 169 #define GIT_WINDOWS_NATIVE
 170 #endif
 171
 172 #include <unistd.h>
 173 #include <stdio.h>
 174 #include <sys/stat.h>
 175 #include <fcntl.h>
 176 #include <stddef.h>
 177 #include <stdlib.h>
 178 #include <stdarg.h>
 179 #include <string.h>
 180 #ifdef HAVE_STRINGS_H
 181 #include <strings.h> /* for strcasecmp() */
 182 #endif
 183 #include <errno.h>
 184 #include <limits.h>
 185 #ifdef NEEDS_SYS_PARAM_H
 186 #include <sys/param.h>
 187 #endif
 188 #include <sys/types.h>
 189 #include <dirent.h>
 190 #include <sys/time.h>
 191 #include <time.h>
 192 #include <signal.h>
 193 #include <assert.h>
 194 #include <regex.h>
 195 #include <utime.h>
 196 #include <syslog.h>
 197 #if !defined(NO_POLL_H)
 198 #include <poll.h>
 199 #elif !defined(NO_SYS_POLL_H)
 200 #include <sys/poll.h>
 201 #else
 202 /* Pull the compat stuff */
 203 #include <poll.h>
 204 #endif
 205 #ifdef HAVE_BSD_SYSCTL
 206 #include <sys/sysctl.h>
 207 #endif
 208
 209 #if defined(__CYGWIN__)
 210 #include "compat/win32/path-utils.h"
 211 #endif
 212 #if defined(__MINGW32__)
 213 /* pull in Windows compatibility stuff */
 214 #include "compat/win32/path-utils.h"
 215 #include "compat/mingw.h"
 216 #elif defined(_MSC_VER)
 217 #include "compat/win32/path-utils.h"
 218 #include "compat/msvc.h"
 219 #else
 220 #include <sys/utsname.h>
 221 #include <sys/wait.h>
 222 #include <sys/resource.h>
 223 #include <sys/socket.h>
 224 #include <sys/ioctl.h>
 225 #include <termios.h>
 226 #ifndef NO_SYS_SELECT_H
 227 #include <sys/select.h>
 228 #endif
 229 #include <netinet/in.h>
 230 #include <netinet/tcp.h>
 231 #include <arpa/inet.h>
 232 #include <netdb.h>
 233 #include <pwd.h>
 234 #include <sys/un.h>
 235 #ifndef NO_INTTYPES_H
 236 #include <inttypes.h>
 237 #else
 238 #include <stdint.h>
 239 #endif
 240 #ifdef NO_INTPTR_T
 241 /*
 242  * On I16LP32, ILP32 and LP64 "long" is the safe bet, however
 243  * on LLP86, IL33LLP64 and P64 it needs to be "long long",
 244  * while on IP16 and IP16L32 it is "int" (resp. "short")
 245  * Size needs to match (or exceed) 'sizeof(void *)'.
 246  * We can't take "long long" here as not everybody has it.
 247  */
 248 typedef long intptr_t;
 249 typedef unsigned long uintptr_t;
 250 #endif
 251 #undef _ALL_SOURCE /* AIX 5.3L defines a struct list with _ALL_SOURCE. */
 252 #include <grp.h>
 253 #define _ALL_SOURCE 1
 254 #endif
 255
 256 /* used on Mac OS X */
 257 #ifdef PRECOMPOSE_UNICODE
 258 #include "compat/precompose_utf8.h"
 259 #else
 260 static inline const char *precompose_argv_prefix(int argc, const char **argv, const char *prefix)
 261 {
 262         return prefix;
 263 }
 264 static inline const char *precompose_string_if_needed(const char *in)
 265 {
 266         return in;
 267 }
 268
 269 #define probe_utf8_pathname_composition()
 270 #endif
 271
 272 #ifdef MKDIR_WO_TRAILING_SLASH
 273 #define mkdir(a,b) compat_mkdir_wo_trailing_slash((a),(b))
 274 int compat_mkdir_wo_trailing_slash(const char*, mode_t);
 275 #endif
 276
 277 #ifdef NO_STRUCT_ITIMERVAL
 278 struct itimerval {
 279         struct timeval it_interval;
 280         struct timeval it_value;
 281 };
 282 #endif
 283
 284 #ifdef NO_SETITIMER
 285 static inline int setitimer(int which, const struct itimerval *value, struct itimerval *newvalue) {
 286         return 0; /* pretend success */
 287 }
 288 #endif
 289
 290 #ifndef NO_LIBGEN_H
 291 #include <libgen.h>
 292 #else
 293 #define basename gitbasename
 294 char *gitbasename(char *);
 295 #define dirname gitdirname
 296 char *gitdirname(char *);
 297 #endif
 298
 299 #ifndef NO_ICONV
 300 #include <iconv.h>
 301 #endif
 302
 303 #ifndef NO_OPENSSL
 304 #ifdef __APPLE__
 305 #define __AVAILABILITY_MACROS_USES_AVAILABILITY 0
 306 #include <AvailabilityMacros.h>
 307 #undef DEPRECATED_ATTRIBUTE
 308 #define DEPRECATED_ATTRIBUTE
 309 #undef __AVAILABILITY_MACROS_USES_AVAILABILITY
 310 #endif
 311 #include <openssl/ssl.h>
 312 #include <openssl/err.h>
 313 #endif
 314
 315 #ifdef HAVE_SYSINFO
 316 # include <sys/sysinfo.h>
 317 #endif
 318
 319 /* On most systems <netdb.h> would have given us this, but
 320  * not on some systems (e.g. z/OS).
 321  */
 322 #ifndef NI_MAXHOST
 323 #define NI_MAXHOST 1025
 324 #endif
 325
 326 #ifndef NI_MAXSERV
 327 #define NI_MAXSERV 32
 328 #endif
 329
 330 /* On most systems <limits.h> would have given us this, but
 331  * not on some systems (e.g. GNU/Hurd).
 332  */
 333 #ifndef PATH_MAX
 334 #define PATH_MAX 4096
 335 #endif
 336
 337 typedef uintmax_t timestamp_t;
 338 #define PRItime PRIuMAX
 339 #define parse_timestamp strtoumax
 340 #define TIME_MAX UINTMAX_MAX
 341 #define TIME_MIN 0
 342
 343 #ifndef PATH_SEP
 344 #define PATH_SEP ':'
 345 #endif
 346
 347 #ifdef HAVE_PATHS_H
 348 #include <paths.h>
 349 #endif
 350 #ifndef _PATH_DEFPATH
 351 #define _PATH_DEFPATH "/usr/local/bin:/usr/bin:/bin"
 352 #endif
 353
 354 #ifndef platform_core_config
 355 static inline int noop_core_config(const char *var, const char *value, void *cb)
 356 {
 357         return 0;
 358 }
 359 #define platform_core_config noop_core_config
 360 #endif
 361
 362 int lstat_cache_aware_rmdir(const char *path);
 363 #if !defined(__MINGW32__) && !defined(_MSC_VER)
 364 #define rmdir lstat_cache_aware_rmdir
 365 #endif
 366
 367 #ifndef has_dos_drive_prefix
 368 static inline int git_has_dos_drive_prefix(const char *path)
 369 {
 370         return 0;
 371 }
 372 #define has_dos_drive_prefix git_has_dos_drive_prefix
 373 #endif
 374
 375 #ifndef skip_dos_drive_prefix
 376 static inline int git_skip_dos_drive_prefix(char **path)
 377 {
 378         return 0;
 379 }
 380 #define skip_dos_drive_prefix git_skip_dos_drive_prefix
 381 #endif
 382
 383 #ifndef is_dir_sep
 384 static inline int git_is_dir_sep(int c)
 385 {
 386         return c == '/';
 387 }
 388 #define is_dir_sep git_is_dir_sep
 389 #endif
 390
 391 #ifndef offset_1st_component
 392 static inline int git_offset_1st_component(const char *path)
 393 {
 394         return is_dir_sep(path[0]);
 395 }
 396 #define offset_1st_component git_offset_1st_component
 397 #endif
 398
 399 #ifndef is_valid_path
 400 #define is_valid_path(path) 1
 401 #endif
 402
 403 #ifndef is_path_owned_by_current_user
 404
 405 #ifdef __TANDEM
 406 #define ROOT_UID 65535
 407 #else
 408 #define ROOT_UID 0
 409 #endif
 410
 411 /*
 412  * Do not use this function when
 413  * (1) geteuid() did not say we are running as 'root', or
 414  * (2) using this function will compromise the system.
 415  *
 416  * PORTABILITY WARNING:
 417  * This code assumes uid_t is unsigned because that is what sudo does.
 418  * If your uid_t type is signed and all your ids are positive then it
 419  * should all work fine.
 420  * If your version of sudo uses negative values for uid_t or it is
 421  * buggy and return an overflowed value in SUDO_UID, then git might
 422  * fail to grant access to your repository properly or even mistakenly
 423  * grant access to someone else.
 424  * In the unlikely scenario this happened to you, and that is how you
 425  * got to this message, we would like to know about it; so sent us an
 426  * email to git@vger.kernel.org indicating which platform you are
 427  * using and which version of sudo, so we can improve this logic and
 428  * maybe provide you with a patch that would prevent this issue again
 429  * in the future.
 430  */
 431 static inline void extract_id_from_env(const char *env, uid_t *id)
 432 {
 433         const char *real_uid = getenv(env);
 434
 435         /* discard anything empty to avoid a more complex check below */
 436         if (real_uid && *real_uid) {
 437                 char *endptr = NULL;
 438                 unsigned long env_id;
 439
 440                 errno = 0;
 441                 /* silent overflow errors could trigger a bug here */
 442                 env_id = strtoul(real_uid, &endptr, 10);
 443                 if (!*endptr && !errno)
 444                         *id = env_id;
 445         }
 446 }
 447
 448 static inline int is_path_owned_by_current_uid(const char *path)
 449 {
 450         struct stat st;
 451         uid_t euid;
 452
 453         if (lstat(path, &st))
 454                 return 0;
 455
 456         euid = geteuid();
 457         if (euid == ROOT_UID)
 458         {
 459                 if (st.st_uid == ROOT_UID)
 460                         return 1;
 461                 else
 462                         extract_id_from_env("SUDO_UID", &euid);
 463         }
 464
 465         return st.st_uid == euid;
 466 }
 467
 468 #define is_path_owned_by_current_user is_path_owned_by_current_uid
 469 #endif
 470
 471 #ifndef find_last_dir_sep
 472 static inline char *git_find_last_dir_sep(const char *path)
 473 {
 474         return strrchr(path, '/');
 475 }
 476 #define find_last_dir_sep git_find_last_dir_sep
 477 #endif
 478
 479 #ifndef has_dir_sep
 480 static inline int git_has_dir_sep(const char *path)
 481 {
 482         return !!strchr(path, '/');
 483 }
 484 #define has_dir_sep(path) git_has_dir_sep(path)
 485 #endif
 486
 487 #ifndef query_user_email
 488 #define query_user_email() NULL
 489 #endif
 490
 491 #ifdef __TANDEM
 492 #include <floss.h(floss_execl,floss_execlp,floss_execv,floss_execvp)>
 493 #include <floss.h(floss_getpwuid)>
 494 #ifndef NSIG
 495 /*
 496  * NonStop NSE and NSX do not provide NSIG. SIGGUARDIAN(99) is the highest
 497  * known, by detective work using kill -l as a list is all signals
 498  * instead of signal.h where it should be.
 499  */
 500 # define NSIG 100
 501 #endif
 502 #endif
 503
 504 #if defined(__HP_cc) && (__HP_cc >= 61000)
 505 #define NORETURN __attribute__((noreturn))
 506 #define NORETURN_PTR
 507 #elif defined(__GNUC__) && !defined(NO_NORETURN)
 508 #define NORETURN __attribute__((__noreturn__))
 509 #define NORETURN_PTR __attribute__((__noreturn__))
 510 #elif defined(_MSC_VER)
 511 #define NORETURN __declspec(noreturn)
 512 #define NORETURN_PTR
 513 #else
 514 #define NORETURN
 515 #define NORETURN_PTR
 516 #ifndef __GNUC__
 517 #ifndef __attribute__
 518 #define __attribute__(x)
 519 #endif
 520 #endif
 521 #endif
 522
 523 /* The sentinel attribute is valid from gcc version 4.0 */
 524 #if defined(__GNUC__) && (__GNUC__ >= 4)
 525 #define LAST_ARG_MUST_BE_NULL __attribute__((sentinel))
 526 #else
 527 #define LAST_ARG_MUST_BE_NULL
 528 #endif
 529
 530 #define MAYBE_UNUSED __attribute__((__unused__))
 531
 532 #include "compat/bswap.h"
 533
 534 #include "wildmatch.h"
 535
 536 struct strbuf;
 537
 538 /* General helper functions */
 539 void vreportf(const char *prefix, const char *err, va_list params);
 540 NORETURN void usage(const char *err);
 541 NORETURN void usagef(const char *err, ...) __attribute__((format (printf, 1, 2)));
 542 NORETURN void die(const char *err, ...) __attribute__((format (printf, 1, 2)));
 543 NORETURN void die_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
 544 int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
 545 int error_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
 546 void warning(const char *err, ...) __attribute__((format (printf, 1, 2)));
 547 void warning_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
 548
 549 #ifndef NO_OPENSSL
 550 #ifdef APPLE_COMMON_CRYPTO
 551 #include "compat/apple-common-crypto.h"
 552 #else
 553 #include <openssl/evp.h>
 554 #include <openssl/hmac.h>
 555 #endif /* APPLE_COMMON_CRYPTO */
 556 #include <openssl/x509v3.h>
 557 #endif /* NO_OPENSSL */
 558
 559 /*
 560  * Let callers be aware of the constant return value; this can help
 561  * gcc with -Wuninitialized analysis. We restrict this trick to gcc, though,
 562  * because some compilers may not support variadic macros. Since we're only
 563  * trying to help gcc, anyway, it's OK; other compilers will fall back to
 564  * using the function as usual.
 565  */
 566 #if defined(__GNUC__)
 567 static inline int const_error(void)
 568 {
 569         return -1;
 570 }
 571 #define error(...) (error(__VA_ARGS__), const_error())
 572 #define error_errno(...) (error_errno(__VA_ARGS__), const_error())
 573 #endif
 574
 575 typedef void (*report_fn)(const char *, va_list params);
 576
 577 void set_die_routine(NORETURN_PTR report_fn routine);
 578 void set_error_routine(report_fn routine);
 579 report_fn get_error_routine(void);
 580 void set_warn_routine(report_fn routine);
 581 report_fn get_warn_routine(void);
 582 void set_die_is_recursing_routine(int (*routine)(void));
 583
 584 int starts_with(const char *str, const char *prefix);
 585 int istarts_with(const char *str, const char *prefix);
 586
 587 /*
 588  * If the string "str" begins with the string found in "prefix", return 1.
 589  * The "out" parameter is set to "str + strlen(prefix)" (i.e., to the point in
 590  * the string right after the prefix).
 591  *
 592  * Otherwise, return 0 and leave "out" untouched.
 593  *
 594  * Examples:
 595  *
 596  *   [extract branch name, fail if not a branch]
 597  *   if (!skip_prefix(ref, "refs/heads/", &branch)
 598  *      return -1;
 599  *
 600  *   [skip prefix if present, otherwise use whole string]
 601  *   skip_prefix(name, "refs/heads/", &name);
 602  */
 603 static inline int skip_prefix(const char *str, const char *prefix,
 604                               const char **out)
 605 {
 606         do {
 607                 if (!*prefix) {
 608                         *out = str;
 609                         return 1;
 610                 }
 611         } while (*str++ == *prefix++);
 612         return 0;
 613 }
 614
 615 /*
 616  * If the string "str" is the same as the string in "prefix", then the "arg"
 617  * parameter is set to the "def" parameter and 1 is returned.
 618  * If the string "str" begins with the string found in "prefix" and then a
 619  * "=" sign, then the "arg" parameter is set to "str + strlen(prefix) + 1"
 620  * (i.e., to the point in the string right after the prefix and the "=" sign),
 621  * and 1 is returned.
 622  *
 623  * Otherwise, return 0 and leave "arg" untouched.
 624  *
 625  * When we accept both a "--key" and a "--key=<val>" option, this function
 626  * can be used instead of !strcmp(arg, "--key") and then
 627  * skip_prefix(arg, "--key=", &arg) to parse such an option.
 628  */
 629 int skip_to_optional_arg_default(const char *str, const char *prefix,
 630                                  const char **arg, const char *def);
 631
 632 static inline int skip_to_optional_arg(const char *str, const char *prefix,
 633                                        const char **arg)
 634 {
 635         return skip_to_optional_arg_default(str, prefix, arg, "");
 636 }
 637
 638 /*
 639  * Like skip_prefix, but promises never to read past "len" bytes of the input
 640  * buffer, and returns the remaining number of bytes in "out" via "outlen".
 641  */
 642 static inline int skip_prefix_mem(const char *buf, size_t len,
 643                                   const char *prefix,
 644                                   const char **out, size_t *outlen)
 645 {
 646         size_t prefix_len = strlen(prefix);
 647         if (prefix_len <= len && !memcmp(buf, prefix, prefix_len)) {
 648                 *out = buf + prefix_len;
 649                 *outlen = len - prefix_len;
 650                 return 1;
 651         }
 652         return 0;
 653 }
 654
 655 /*
 656  * If buf ends with suffix, return 1 and subtract the length of the suffix
 657  * from *len. Otherwise, return 0 and leave *len untouched.
 658  */
 659 static inline int strip_suffix_mem(const char *buf, size_t *len,
 660                                    const char *suffix)
 661 {
 662         size_t suflen = strlen(suffix);
 663         if (*len < suflen || memcmp(buf + (*len - suflen), suffix, suflen))
 664                 return 0;
 665         *len -= suflen;
 666         return 1;
 667 }
 668
 669 /*
 670  * If str ends with suffix, return 1 and set *len to the size of the string
 671  * without the suffix. Otherwise, return 0 and set *len to the size of the
 672  * string.
 673  *
 674  * Note that we do _not_ NUL-terminate str to the new length.
 675  */
 676 static inline int strip_suffix(const char *str, const char *suffix, size_t *len)
 677 {
 678         *len = strlen(str);
 679         return strip_suffix_mem(str, len, suffix);
 680 }
 681
 682 static inline int ends_with(const char *str, const char *suffix)
 683 {
 684         size_t len;
 685         return strip_suffix(str, suffix, &len);
 686 }
 687
 688 #define SWAP(a, b) do {                                         \
 689         void *_swap_a_ptr = &(a);                               \
 690         void *_swap_b_ptr = &(b);                               \
 691         unsigned char _swap_buffer[sizeof(a)];                  \
 692         memcpy(_swap_buffer, _swap_a_ptr, sizeof(a));           \
 693         memcpy(_swap_a_ptr, _swap_b_ptr, sizeof(a) +            \
 694                BUILD_ASSERT_OR_ZERO(sizeof(a) == sizeof(b)));   \
 695         memcpy(_swap_b_ptr, _swap_buffer, sizeof(a));           \
 696 } while (0)
 697
 698 #if defined(NO_MMAP) || defined(USE_WIN32_MMAP)
 699
 700 #ifndef PROT_READ
 701 #define PROT_READ 1
 702 #define PROT_WRITE 2
 703 #define MAP_PRIVATE 1
 704 #endif
 705
 706 #define mmap git_mmap
 707 #define munmap git_munmap
 708 void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset);
 709 int git_munmap(void *start, size_t length);
 710
 711 #else /* NO_MMAP || USE_WIN32_MMAP */
 712
 713 #include <sys/mman.h>
 714
 715 #endif /* NO_MMAP || USE_WIN32_MMAP */
 716
 717 #ifdef NO_MMAP
 718
 719 /* This value must be multiple of (pagesize * 2) */
 720 #define DEFAULT_PACKED_GIT_WINDOW_SIZE (1 * 1024 * 1024)
 721
 722 #else /* NO_MMAP */
 723
 724 /* This value must be multiple of (pagesize * 2) */
 725 #define DEFAULT_PACKED_GIT_WINDOW_SIZE \
 726         (sizeof(void*) >= 8 \
 727                 ?  1 * 1024 * 1024 * 1024 \
 728                 : 32 * 1024 * 1024)
 729
 730 #endif /* NO_MMAP */
 731
 732 #ifndef MAP_FAILED
 733 #define MAP_FAILED ((void *)-1)
 734 #endif
 735
 736 #ifdef NO_ST_BLOCKS_IN_STRUCT_STAT
 737 #define on_disk_bytes(st) ((st).st_size)
 738 #else
 739 #define on_disk_bytes(st) ((st).st_blocks * 512)
 740 #endif
 741
 742 #ifdef NEEDS_MODE_TRANSLATION
 743 #undef S_IFMT
 744 #undef S_IFREG
 745 #undef S_IFDIR
 746 #undef S_IFLNK
 747 #undef S_IFBLK
 748 #undef S_IFCHR
 749 #undef S_IFIFO
 750 #undef S_IFSOCK
 751 #define S_IFMT   0170000
 752 #define S_IFREG  0100000
 753 #define S_IFDIR  0040000
 754 #define S_IFLNK  0120000
 755 #define S_IFBLK  0060000
 756 #define S_IFCHR  0020000
 757 #define S_IFIFO  0010000
 758 #define S_IFSOCK 0140000
 759 #ifdef stat
 760 #undef stat
 761 #endif
 762 #define stat(path, buf) git_stat(path, buf)
 763 int git_stat(const char *, struct stat *);
 764 #ifdef fstat
 765 #undef fstat
 766 #endif
 767 #define fstat(fd, buf) git_fstat(fd, buf)
 768 int git_fstat(int, struct stat *);
 769 #ifdef lstat
 770 #undef lstat
 771 #endif
 772 #define lstat(path, buf) git_lstat(path, buf)
 773 int git_lstat(const char *, struct stat *);
 774 #endif
 775
 776 #define DEFAULT_PACKED_GIT_LIMIT \
 777         ((1024L * 1024L) * (size_t)(sizeof(void*) >= 8 ? (32 * 1024L * 1024L) : 256))
 778
 779 #ifdef NO_PREAD
 780 #define pread git_pread
 781 ssize_t git_pread(int fd, void *buf, size_t count, off_t offset);
 782 #endif
 783 /*
 784  * Forward decl that will remind us if its twin in cache.h changes.
 785  * This function is used in compat/pread.c.  But we can't include
 786  * cache.h there.
 787  */
 788 ssize_t read_in_full(int fd, void *buf, size_t count);
 789
 790 #ifdef NO_SETENV
 791 #define setenv gitsetenv
 792 int gitsetenv(const char *, const char *, int);
 793 #endif
 794
 795 #ifdef NO_MKDTEMP
 796 #define mkdtemp gitmkdtemp
 797 char *gitmkdtemp(char *);
 798 #endif
 799
 800 #ifdef NO_UNSETENV
 801 #define unsetenv gitunsetenv
 802 void gitunsetenv(const char *);
 803 #endif
 804
 805 #ifdef NO_STRCASESTR
 806 #define strcasestr gitstrcasestr
 807 char *gitstrcasestr(const char *haystack, const char *needle);
 808 #endif
 809
 810 #ifdef NO_STRLCPY
 811 #define strlcpy gitstrlcpy
 812 size_t gitstrlcpy(char *, const char *, size_t);
 813 #endif
 814
 815 #ifdef NO_STRTOUMAX
 816 #define strtoumax gitstrtoumax
 817 uintmax_t gitstrtoumax(const char *, char **, int);
 818 #define strtoimax gitstrtoimax
 819 intmax_t gitstrtoimax(const char *, char **, int);
 820 #endif
 821
 822 #ifdef NO_HSTRERROR
 823 #define hstrerror githstrerror
 824 const char *githstrerror(int herror);
 825 #endif
 826
 827 #ifdef NO_MEMMEM
 828 #define memmem gitmemmem
 829 void *gitmemmem(const void *haystack, size_t haystacklen,
 830                 const void *needle, size_t needlelen);
 831 #endif
 832
 833 #ifdef OVERRIDE_STRDUP
 834 #ifdef strdup
 835 #undef strdup
 836 #endif
 837 #define strdup gitstrdup
 838 char *gitstrdup(const char *s);
 839 #endif
 840
 841 #ifdef NO_GETPAGESIZE
 842 #define getpagesize() sysconf(_SC_PAGESIZE)
 843 #endif
 844
 845 #ifndef O_CLOEXEC
 846 #define O_CLOEXEC 0
 847 #endif
 848
 849 #ifdef FREAD_READS_DIRECTORIES
 850 # if !defined(SUPPRESS_FOPEN_REDEFINITION)
 851 #  ifdef fopen
 852 #   undef fopen
 853 #  endif
 854 #  define fopen(a,b) git_fopen(a,b)
 855 # endif
 856 FILE *git_fopen(const char*, const char*);
 857 #endif
 858
 859 #ifdef SNPRINTF_RETURNS_BOGUS
 860 #ifdef snprintf
 861 #undef snprintf
 862 #endif
 863 #define snprintf git_snprintf
 864 int git_snprintf(char *str, size_t maxsize,
 865                  const char *format, ...);
 866 #ifdef vsnprintf
 867 #undef vsnprintf
 868 #endif
 869 #define vsnprintf git_vsnprintf
 870 int git_vsnprintf(char *str, size_t maxsize,
 871                   const char *format, va_list ap);
 872 #endif
 873
 874 #ifdef OPEN_RETURNS_EINTR
 875 #undef open
 876 #define open git_open_with_retry
 877 int git_open_with_retry(const char *path, int flag, ...);
 878 #endif
 879
 880 #ifdef __GLIBC_PREREQ
 881 #if __GLIBC_PREREQ(2, 1)
 882 #define HAVE_STRCHRNUL
 883 #endif
 884 #endif
 885
 886 #ifndef HAVE_STRCHRNUL
 887 #define strchrnul gitstrchrnul
 888 static inline char *gitstrchrnul(const char *s, int c)
 889 {
 890         while (*s && *s != c)
 891                 s++;
 892         return (char *)s;
 893 }
 894 #endif
 895
 896 #ifdef NO_INET_PTON
 897 int inet_pton(int af, const char *src, void *dst);
 898 #endif
 899
 900 #ifdef NO_INET_NTOP
 901 const char *inet_ntop(int af, const void *src, char *dst, size_t size);
 902 #endif
 903
 904 #ifdef NO_PTHREADS
 905 #define atexit git_atexit
 906 int git_atexit(void (*handler)(void));
 907 #endif
 908
 909 static inline size_t st_add(size_t a, size_t b)
 910 {
 911         if (unsigned_add_overflows(a, b))
 912                 die("size_t overflow: %"PRIuMAX" + %"PRIuMAX,
 913                     (uintmax_t)a, (uintmax_t)b);
 914         return a + b;
 915 }
 916 #define st_add3(a,b,c)   st_add(st_add((a),(b)),(c))
 917 #define st_add4(a,b,c,d) st_add(st_add3((a),(b),(c)),(d))
 918
 919 static inline size_t st_mult(size_t a, size_t b)
 920 {
 921         if (unsigned_mult_overflows(a, b))
 922                 die("size_t overflow: %"PRIuMAX" * %"PRIuMAX,
 923                     (uintmax_t)a, (uintmax_t)b);
 924         return a * b;
 925 }
 926
 927 static inline size_t st_sub(size_t a, size_t b)
 928 {
 929         if (a < b)
 930                 die("size_t underflow: %"PRIuMAX" - %"PRIuMAX,
 931                     (uintmax_t)a, (uintmax_t)b);
 932         return a - b;
 933 }
 934
 935 #ifdef HAVE_ALLOCA_H
 936 # include <alloca.h>
 937 # define xalloca(size)      (alloca(size))
 938 # define xalloca_free(p)    do {} while (0)
 939 #else
 940 # define xalloca(size)      (xmalloc(size))
 941 # define xalloca_free(p)    (free(p))
 942 #endif
 943 char *xstrdup(const char *str);
 944 void *xmalloc(size_t size);
 945 void *xmallocz(size_t size);
 946 void *xmallocz_gently(size_t size);
 947 void *xmemdupz(const void *data, size_t len);
 948 char *xstrndup(const char *str, size_t len);
 949 void *xrealloc(void *ptr, size_t size);
 950 void *xcalloc(size_t nmemb, size_t size);
 951 void xsetenv(const char *name, const char *value, int overwrite);
 952 void *xmmap(void *start, size_t length, int prot, int flags, int fd, off_t offset);
 953 const char *mmap_os_err(void);
 954 void *xmmap_gently(void *start, size_t length, int prot, int flags, int fd, off_t offset);
 955 int xopen(const char *path, int flags, ...);
 956 ssize_t xread(int fd, void *buf, size_t len);
 957 ssize_t xwrite(int fd, const void *buf, size_t len);
 958 ssize_t xpread(int fd, void *buf, size_t len, off_t offset);
 959 int xdup(int fd);
 960 FILE *xfopen(const char *path, const char *mode);
 961 FILE *xfdopen(int fd, const char *mode);
 962 int xmkstemp(char *temp_filename);
 963 int xmkstemp_mode(char *temp_filename, int mode);
 964 char *xgetcwd(void);
 965 FILE *fopen_for_writing(const char *path);
 966 FILE *fopen_or_warn(const char *path, const char *mode);
 967
 968 /*
 969  * Like strncmp, but only return zero if s is NUL-terminated and exactly len
 970  * characters long.  If it is not, consider it greater than t.
 971  */
 972 int xstrncmpz(const char *s, const char *t, size_t len);
 973
 974 /*
 975  * FREE_AND_NULL(ptr) is like free(ptr) followed by ptr = NULL. Note
 976  * that ptr is used twice, so don't pass e.g. ptr++.
 977  */
 978 #define FREE_AND_NULL(p) do { free(p); (p) = NULL; } while (0)
 979
 980 #define ALLOC_ARRAY(x, alloc) (x) = xmalloc(st_mult(sizeof(*(x)), (alloc)))
 981 #define CALLOC_ARRAY(x, alloc) (x) = xcalloc((alloc), sizeof(*(x)))
 982 #define REALLOC_ARRAY(x, alloc) (x) = xrealloc((x), st_mult(sizeof(*(x)), (alloc)))
 983
 984 #define COPY_ARRAY(dst, src, n) copy_array((dst), (src), (n), sizeof(*(dst)) + \
 985         BUILD_ASSERT_OR_ZERO(sizeof(*(dst)) == sizeof(*(src))))
 986 static inline void copy_array(void *dst, const void *src, size_t n, size_t size)
 987 {
 988         if (n)
 989                 memcpy(dst, src, st_mult(size, n));
 990 }
 991
 992 #define MOVE_ARRAY(dst, src, n) move_array((dst), (src), (n), sizeof(*(dst)) + \
 993         BUILD_ASSERT_OR_ZERO(sizeof(*(dst)) == sizeof(*(src))))
 994 static inline void move_array(void *dst, const void *src, size_t n, size_t size)
 995 {
 996         if (n)
 997                 memmove(dst, src, st_mult(size, n));
 998 }
 999
1000 /*
1001  * These functions help you allocate structs with flex arrays, and copy
1002  * the data directly into the array. For example, if you had:
1003  *
1004  *   struct foo {
1005  *     int bar;
1006  *     char name[FLEX_ARRAY];
1007  *   };
1008  *
1009  * you can do:
1010  *
1011  *   struct foo *f;
1012  *   FLEX_ALLOC_MEM(f, name, src, len);
1013  *
1014  * to allocate a "foo" with the contents of "src" in the "name" field.
1015  * The resulting struct is automatically zero'd, and the flex-array field
1016  * is NUL-terminated (whether the incoming src buffer was or not).
1017  *
1018  * The FLEXPTR_* variants operate on structs that don't use flex-arrays,
1019  * but do want to store a pointer to some extra data in the same allocated
1020  * block. For example, if you have:
1021  *
1022  *   struct foo {
1023  *     char *name;
1024  *     int bar;
1025  *   };
1026  *
1027  * you can do:
1028  *
1029  *   struct foo *f;
1030  *   FLEXPTR_ALLOC_STR(f, name, src);
1031  *
1032  * and "name" will point to a block of memory after the struct, which will be
1033  * freed along with the struct (but the pointer can be repointed anywhere).
1034  *
1035  * The *_STR variants accept a string parameter rather than a ptr/len
1036  * combination.
1037  *
1038  * Note that these macros will evaluate the first parameter multiple
1039  * times, and it must be assignable as an lvalue.
1040  */
1041 #define FLEX_ALLOC_MEM(x, flexname, buf, len) do { \
1042         size_t flex_array_len_ = (len); \
1043         (x) = xcalloc(1, st_add3(sizeof(*(x)), flex_array_len_, 1)); \
1044         memcpy((void *)(x)->flexname, (buf), flex_array_len_); \
1045 } while (0)
1046 #define FLEXPTR_ALLOC_MEM(x, ptrname, buf, len) do { \
1047         size_t flex_array_len_ = (len); \
1048         (x) = xcalloc(1, st_add3(sizeof(*(x)), flex_array_len_, 1)); \
1049         memcpy((x) + 1, (buf), flex_array_len_); \
1050         (x)->ptrname = (void *)((x)+1); \
1051 } while(0)
1052 #define FLEX_ALLOC_STR(x, flexname, str) \
1053         FLEX_ALLOC_MEM((x), flexname, (str), strlen(str))
1054 #define FLEXPTR_ALLOC_STR(x, ptrname, str) \
1055         FLEXPTR_ALLOC_MEM((x), ptrname, (str), strlen(str))
1056
1057 static inline char *xstrdup_or_null(const char *str)
1058 {
1059         return str ? xstrdup(str) : NULL;
1060 }
1061
1062 static inline size_t xsize_t(off_t len)
1063 {
1064         if (len < 0 || (uintmax_t) len > SIZE_MAX)
1065                 die("Cannot handle files this big");
1066         return (size_t) len;
1067 }
1068
1069 __attribute__((format (printf, 3, 4)))
1070 int xsnprintf(char *dst, size_t max, const char *fmt, ...);
1071
1072 #ifndef HOST_NAME_MAX
1073 #define HOST_NAME_MAX 256
1074 #endif
1075
1076 int xgethostname(char *buf, size_t len);
1077
1078 /* in ctype.c, for kwset users */
1079 extern const unsigned char tolower_trans_tbl[256];
1080
1081 /* Sane ctype - no locale, and works with signed chars */
1082 #undef isascii
1083 #undef isspace
1084 #undef isdigit
1085 #undef isalpha
1086 #undef isalnum
1087 #undef isprint
1088 #undef islower
1089 #undef isupper
1090 #undef tolower
1091 #undef toupper
1092 #undef iscntrl
1093 #undef ispunct
1094 #undef isxdigit
1095
1096 extern const unsigned char sane_ctype[256];
1097 #define GIT_SPACE 0x01
1098 #define GIT_DIGIT 0x02
1099 #define GIT_ALPHA 0x04
1100 #define GIT_GLOB_SPECIAL 0x08
1101 #define GIT_REGEX_SPECIAL 0x10
1102 #define GIT_PATHSPEC_MAGIC 0x20
1103 #define GIT_CNTRL 0x40
1104 #define GIT_PUNCT 0x80
1105 #define sane_istest(x,mask) ((sane_ctype[(unsigned char)(x)] & (mask)) != 0)
1106 #define isascii(x) (((x) & ~0x7f) == 0)
1107 #define isspace(x) sane_istest(x,GIT_SPACE)
1108 #define isdigit(x) sane_istest(x,GIT_DIGIT)
1109 #define isalpha(x) sane_istest(x,GIT_ALPHA)
1110 #define isalnum(x) sane_istest(x,GIT_ALPHA | GIT_DIGIT)
1111 #define isprint(x) ((x) >= 0x20 && (x) <= 0x7e)
1112 #define islower(x) sane_iscase(x, 1)
1113 #define isupper(x) sane_iscase(x, 0)
1114 #define is_glob_special(x) sane_istest(x,GIT_GLOB_SPECIAL)
1115 #define is_regex_special(x) sane_istest(x,GIT_GLOB_SPECIAL | GIT_REGEX_SPECIAL)
1116 #define iscntrl(x) (sane_istest(x,GIT_CNTRL))
1117 #define ispunct(x) sane_istest(x, GIT_PUNCT | GIT_REGEX_SPECIAL | \
1118                 GIT_GLOB_SPECIAL | GIT_PATHSPEC_MAGIC)
1119 #define isxdigit(x) (hexval_table[(unsigned char)(x)] != -1)
1120 #define tolower(x) sane_case((unsigned char)(x), 0x20)
1121 #define toupper(x) sane_case((unsigned char)(x), 0)
1122 #define is_pathspec_magic(x) sane_istest(x,GIT_PATHSPEC_MAGIC)
1123
1124 static inline int sane_case(int x, int high)
1125 {
1126         if (sane_istest(x, GIT_ALPHA))
1127                 x = (x & ~0x20) | high;
1128         return x;
1129 }
1130
1131 static inline int sane_iscase(int x, int is_lower)
1132 {
1133         if (!sane_istest(x, GIT_ALPHA))
1134                 return 0;
1135
1136         if (is_lower)
1137                 return (x & 0x20) != 0;
1138         else
1139                 return (x & 0x20) == 0;
1140 }
1141
1142 /*
1143  * Like skip_prefix, but compare case-insensitively. Note that the comparison
1144  * is done via tolower(), so it is strictly ASCII (no multi-byte characters or
1145  * locale-specific conversions).
1146  */
1147 static inline int skip_iprefix(const char *str, const char *prefix,
1148                                const char **out)
1149 {
1150         do {
1151                 if (!*prefix) {
1152                         *out = str;
1153                         return 1;
1154                 }
1155         } while (tolower(*str++) == tolower(*prefix++));
1156         return 0;
1157 }
1158
1159 static inline int strtoul_ui(char const *s, int base, unsigned int *result)
1160 {
1161         unsigned long ul;
1162         char *p;
1163
1164         errno = 0;
1165         /* negative values would be accepted by strtoul */
1166         if (strchr(s, '-'))
1167                 return -1;
1168         ul = strtoul(s, &p, base);
1169         if (errno || *p || p == s || (unsigned int) ul != ul)
1170                 return -1;
1171         *result = ul;
1172         return 0;
1173 }
1174
1175 static inline int strtol_i(char const *s, int base, int *result)
1176 {
1177         long ul;
1178         char *p;
1179
1180         errno = 0;
1181         ul = strtol(s, &p, base);
1182         if (errno || *p || p == s || (int) ul != ul)
1183                 return -1;
1184         *result = ul;
1185         return 0;
1186 }
1187
1188 void git_stable_qsort(void *base, size_t nmemb, size_t size,
1189                       int(*compar)(const void *, const void *));
1190 #ifdef INTERNAL_QSORT
1191 #define qsort git_stable_qsort
1192 #endif
1193
1194 #define QSORT(base, n, compar) sane_qsort((base), (n), sizeof(*(base)), compar)
1195 static inline void sane_qsort(void *base, size_t nmemb, size_t size,
1196                               int(*compar)(const void *, const void *))
1197 {
1198         if (nmemb > 1)
1199                 qsort(base, nmemb, size, compar);
1200 }
1201
1202 #define STABLE_QSORT(base, n, compar) \
1203         git_stable_qsort((base), (n), sizeof(*(base)), compar)
1204
1205 #ifndef HAVE_ISO_QSORT_S
1206 int git_qsort_s(void *base, size_t nmemb, size_t size,
1207                 int (*compar)(const void *, const void *, void *), void *ctx);
1208 #define qsort_s git_qsort_s
1209 #endif
1210
1211 #define QSORT_S(base, n, compar, ctx) do {                      \
1212         if (qsort_s((base), (n), sizeof(*(base)), compar, ctx)) \
1213                 BUG("qsort_s() failed");                        \
1214 } while (0)
1215
1216 #ifndef REG_STARTEND
1217 #error "Git requires REG_STARTEND support. Compile with NO_REGEX=NeedsStartEnd"
1218 #endif
1219
1220 static inline int regexec_buf(const regex_t *preg, const char *buf, size_t size,
1221                               size_t nmatch, regmatch_t pmatch[], int eflags)
1222 {
1223         assert(nmatch > 0 && pmatch);
1224         pmatch[0].rm_so = 0;
1225         pmatch[0].rm_eo = size;
1226         return regexec(preg, buf, nmatch, pmatch, eflags | REG_STARTEND);
1227 }
1228
1229 #ifndef DIR_HAS_BSD_GROUP_SEMANTICS
1230 # define FORCE_DIR_SET_GID S_ISGID
1231 #else
1232 # define FORCE_DIR_SET_GID 0
1233 #endif
1234
1235 #ifdef NO_NSEC
1236 #undef USE_NSEC
1237 #define ST_CTIME_NSEC(st) 0
1238 #define ST_MTIME_NSEC(st) 0
1239 #else
1240 #ifdef USE_ST_TIMESPEC
1241 #define ST_CTIME_NSEC(st) ((unsigned int)((st).st_ctimespec.tv_nsec))
1242 #define ST_MTIME_NSEC(st) ((unsigned int)((st).st_mtimespec.tv_nsec))
1243 #else
1244 #define ST_CTIME_NSEC(st) ((unsigned int)((st).st_ctim.tv_nsec))
1245 #define ST_MTIME_NSEC(st) ((unsigned int)((st).st_mtim.tv_nsec))
1246 #endif
1247 #endif
1248
1249 #ifdef UNRELIABLE_FSTAT
1250 #define fstat_is_reliable() 0
1251 #else
1252 #define fstat_is_reliable() 1
1253 #endif
1254
1255 #ifndef va_copy
1256 /*
1257  * Since an obvious implementation of va_list would be to make it a
1258  * pointer into the stack frame, a simple assignment will work on
1259  * many systems.  But let's try to be more portable.
1260  */
1261 #ifdef __va_copy
1262 #define va_copy(dst, src) __va_copy(dst, src)
1263 #else
1264 #define va_copy(dst, src) ((dst) = (src))
1265 #endif
1266 #endif
1267
1268 /*
1269  * This is always defined as a first step towards making the use of variadic
1270  * macros unconditional. If it causes compilation problems on your platform,
1271  * please report it to the Git mailing list at git@vger.kernel.org.
1272  */
1273 #define HAVE_VARIADIC_MACROS 1
1274
1275 /* usage.c: only to be used for testing BUG() implementation (see test-tool) */
1276 extern int BUG_exit_code;
1277
1278 #ifdef HAVE_VARIADIC_MACROS
1279 __attribute__((format (printf, 3, 4))) NORETURN
1280 void BUG_fl(const char *file, int line, const char *fmt, ...);
1281 #define BUG(...) BUG_fl(__FILE__, __LINE__, __VA_ARGS__)
1282 #else
1283 __attribute__((format (printf, 1, 2))) NORETURN
1284 void BUG(const char *fmt, ...);
1285 #endif
1286
1287 /*
1288  * Preserves errno, prints a message, but gives no warning for ENOENT.
1289  * Returns 0 on success, which includes trying to unlink an object that does
1290  * not exist.
1291  */
1292 int unlink_or_warn(const char *path);
1293  /*
1294   * Tries to unlink file.  Returns 0 if unlink succeeded
1295   * or the file already didn't exist.  Returns -1 and
1296   * appends a message to err suitable for
1297   * 'error("%s", err->buf)' on error.
1298   */
1299 int unlink_or_msg(const char *file, struct strbuf *err);
1300 /*
1301  * Preserves errno, prints a message, but gives no warning for ENOENT.
1302  * Returns 0 on success, which includes trying to remove a directory that does
1303  * not exist.
1304  */
1305 int rmdir_or_warn(const char *path);
1306 /*
1307  * Calls the correct function out of {unlink,rmdir}_or_warn based on
1308  * the supplied file mode.
1309  */
1310 int remove_or_warn(unsigned int mode, const char *path);
1311
1312 /*
1313  * Call access(2), but warn for any error except "missing file"
1314  * (ENOENT or ENOTDIR).
1315  */
1316 #define ACCESS_EACCES_OK (1U << 0)
1317 int access_or_warn(const char *path, int mode, unsigned flag);
1318 int access_or_die(const char *path, int mode, unsigned flag);
1319
1320 /* Warn on an inaccessible file if errno indicates this is an error */
1321 int warn_on_fopen_errors(const char *path);
1322
1323 /*
1324  * Open with O_NOFOLLOW, or equivalent. Note that the fallback equivalent
1325  * may be racy. Do not use this as protection against an attacker who can
1326  * simultaneously create paths.
1327  */
1328 int open_nofollow(const char *path, int flags);
1329
1330 #ifndef SHELL_PATH
1331 # define SHELL_PATH "/bin/sh"
1332 #endif
1333
1334 #ifndef _POSIX_THREAD_SAFE_FUNCTIONS
1335 static inline void flockfile(FILE *fh)
1336 {
1337         ; /* nothing */
1338 }
1339 static inline void funlockfile(FILE *fh)
1340 {
1341         ; /* nothing */
1342 }
1343 #define getc_unlocked(fh) getc(fh)
1344 #endif
1345
1346 #ifdef FILENO_IS_A_MACRO
1347 int git_fileno(FILE *stream);
1348 # ifndef COMPAT_CODE_FILENO
1349 #  undef fileno
1350 #  define fileno(p) git_fileno(p)
1351 # endif
1352 #endif
1353
1354 #ifdef NEED_ACCESS_ROOT_HANDLER
1355 int git_access(const char *path, int mode);
1356 # ifndef COMPAT_CODE_ACCESS
1357 #  ifdef access
1358 #  undef access
1359 #  endif
1360 #  define access(path, mode) git_access(path, mode)
1361 # endif
1362 #endif
1363
1364 /*
1365  * Our code often opens a path to an optional file, to work on its
1366  * contents when we can successfully open it.  We can ignore a failure
1367  * to open if such an optional file does not exist, but we do want to
1368  * report a failure in opening for other reasons (e.g. we got an I/O
1369  * error, or the file is there, but we lack the permission to open).
1370  *
1371  * Call this function after seeing an error from open() or fopen() to
1372  * see if the errno indicates a missing file that we can safely ignore.
1373  */
1374 static inline int is_missing_file_error(int errno_)
1375 {
1376         return (errno_ == ENOENT || errno_ == ENOTDIR);
1377 }
1378
1379 int cmd_main(int, const char **);
1380
1381 /*
1382  * Intercept all calls to exit() and route them to trace2 to
1383  * optionally emit a message before calling the real exit().
1384  */
1385 int trace2_cmd_exit_fl(const char *file, int line, int code);
1386 #define exit(code) exit(trace2_cmd_exit_fl(__FILE__, __LINE__, (code)))
1387
1388 /*
1389  * You can mark a stack variable with UNLEAK(var) to avoid it being
1390  * reported as a leak by tools like LSAN or valgrind. The argument
1391  * should generally be the variable itself (not its address and not what
1392  * it points to). It's safe to use this on pointers which may already
1393  * have been freed, or on pointers which may still be in use.
1394  *
1395  * Use this _only_ for a variable that leaks by going out of scope at
1396  * program exit (so only from cmd_* functions or their direct helpers).
1397  * Normal functions, especially those which may be called multiple
1398  * times, should actually free their memory. This is only meant as
1399  * an annotation, and does nothing in non-leak-checking builds.
1400  */
1401 #ifdef SUPPRESS_ANNOTATED_LEAKS
1402 void unleak_memory(const void *ptr, size_t len);
1403 #define UNLEAK(var) unleak_memory(&(var), sizeof(var))
1404 #else
1405 #define UNLEAK(var) do {} while (0)
1406 #endif
1407
1408 /*
1409  * This include must come after system headers, since it introduces macros that
1410  * replace system names.
1411  */
1412 #include "banned.h"
1413
1414 /*
1415  * container_of - Get the address of an object containing a field.
1416  *
1417  * @ptr: pointer to the field.
1418  * @type: type of the object.
1419  * @member: name of the field within the object.
1420  */
1421 #define container_of(ptr, type, member) \
1422         ((type *) ((char *)(ptr) - offsetof(type, member)))
1423
1424 /*
1425  * helper function for `container_of_or_null' to avoid multiple
1426  * evaluation of @ptr
1427  */
1428 static inline void *container_of_or_null_offset(void *ptr, size_t offset)
1429 {
1430         return ptr ? (char *)ptr - offset : NULL;
1431 }
1432
1433 /*
1434  * like `container_of', but allows returned value to be NULL
1435  */
1436 #define container_of_or_null(ptr, type, member) \
1437         (type *)container_of_or_null_offset(ptr, offsetof(type, member))
1438
1439 /*
1440  * like offsetof(), but takes a pointer to a variable of type which
1441  * contains @member, instead of a specified type.
1442  * @ptr is subject to multiple evaluation since we can't rely on __typeof__
1443  * everywhere.
1444  */
1445 #if defined(__GNUC__) /* clang sets this, too */
1446 #define OFFSETOF_VAR(ptr, member) offsetof(__typeof__(*ptr), member)
1447 #else /* !__GNUC__ */
1448 #define OFFSETOF_VAR(ptr, member) \
1449         ((uintptr_t)&(ptr)->member - (uintptr_t)(ptr))
1450 #endif /* !__GNUC__ */
1451
1452 void sleep_millisec(int millisec);
1453
1454 #endif