git-compat-util.h

   1 #ifndef GIT_COMPAT_UTIL_H
   2 #define GIT_COMPAT_UTIL_H
   3
   4 #define _FILE_OFFSET_BITS 64
   5
   6
   7 /* Derived from Linux "Features Test Macro" header
   8  * Convenience macros to test the versions of gcc (or
   9  * a compatible compiler).
  10  * Use them like this:
  11  *  #if GIT_GNUC_PREREQ (2,8)
  12  *   ... code requiring gcc 2.8 or later ...
  13  *  #endif
  14 */
  15 #if defined(__GNUC__) && defined(__GNUC_MINOR__)
  16 # define GIT_GNUC_PREREQ(maj, min) \
  17         ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
  18 #else
  19  #define GIT_GNUC_PREREQ(maj, min) 0
  20 #endif
  21
  22
  23 #ifndef FLEX_ARRAY
  24 /*
  25  * See if our compiler is known to support flexible array members.
  26  */
  27 #if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) && (!defined(__SUNPRO_C) || (__SUNPRO_C > 0x580))
  28 # define FLEX_ARRAY /* empty */
  29 #elif defined(__GNUC__)
  30 # if (__GNUC__ >= 3)
  31 #  define FLEX_ARRAY /* empty */
  32 # else
  33 #  define FLEX_ARRAY 0 /* older GNU extension */
  34 # endif
  35 #endif
  36
  37 /*
  38  * Otherwise, default to safer but a bit wasteful traditional style
  39  */
  40 #ifndef FLEX_ARRAY
  41 # define FLEX_ARRAY 1
  42 #endif
  43 #endif
  44
  45
  46 /*
  47  * BUILD_ASSERT_OR_ZERO - assert a build-time dependency, as an expression.
  48  * @cond: the compile-time condition which must be true.
  49  *
  50  * Your compile will fail if the condition isn't true, or can't be evaluated
  51  * by the compiler.  This can be used in an expression: its value is "0".
  52  *
  53  * Example:
  54  *      #define foo_to_char(foo)                                        \
  55  *               ((char *)(foo)                                         \
  56  *                + BUILD_ASSERT_OR_ZERO(offsetof(struct foo, string) == 0))
  57  */
  58 #define BUILD_ASSERT_OR_ZERO(cond) \
  59         (sizeof(char [1 - 2*!(cond)]) - 1)
  60
  61 #if GIT_GNUC_PREREQ(3, 1)
  62  /* &arr[0] degrades to a pointer: a different type from an array */
  63 # define BARF_UNLESS_AN_ARRAY(arr)                                              \
  64         BUILD_ASSERT_OR_ZERO(!__builtin_types_compatible_p(__typeof__(arr), \
  65                                                            __typeof__(&(arr)[0])))
  66 #else
  67 # define BARF_UNLESS_AN_ARRAY(arr) 0
  68 #endif
  69 /*
  70  * ARRAY_SIZE - get the number of elements in a visible array
  71  *  <at> x: the array whose size you want.
  72  *
  73  * This does not work on pointers, or arrays declared as [], or
  74  * function parameters.  With correct compiler support, such usage
  75  * will cause a build error (see the build_assert_or_zero macro).
  76  */
  77 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]) + BARF_UNLESS_AN_ARRAY(x))
  78
  79 #define bitsizeof(x)  (CHAR_BIT * sizeof(x))
  80
  81 #define maximum_signed_value_of_type(a) \
  82     (INTMAX_MAX >> (bitsizeof(intmax_t) - bitsizeof(a)))
  83
  84 #define maximum_unsigned_value_of_type(a) \
  85     (UINTMAX_MAX >> (bitsizeof(uintmax_t) - bitsizeof(a)))
  86
  87 /*
  88  * Signed integer overflow is undefined in C, so here's a helper macro
  89  * to detect if the sum of two integers will overflow.
  90  *
  91  * Requires: a >= 0, typeof(a) equals typeof(b)
  92  */
  93 #define signed_add_overflows(a, b) \
  94     ((b) > maximum_signed_value_of_type(a) - (a))
  95
  96 #define unsigned_add_overflows(a, b) \
  97     ((b) > maximum_unsigned_value_of_type(a) - (a))
  98
  99 /*
 100  * Returns true if the multiplication of "a" and "b" will
 101  * overflow. The types of "a" and "b" must match and must be unsigned.
 102  * Note that this macro evaluates "a" twice!
 103  */
 104 #define unsigned_mult_overflows(a, b) \
 105     ((a) && (b) > maximum_unsigned_value_of_type(a) / (a))
 106
 107 #ifdef __GNUC__
 108 #define TYPEOF(x) (__typeof__(x))
 109 #else
 110 #define TYPEOF(x)
 111 #endif
 112
 113 #define MSB(x, bits) ((x) & TYPEOF(x)(~0ULL << (bitsizeof(x) - (bits))))
 114 #define HAS_MULTI_BITS(i)  ((i) & ((i) - 1))  /* checks if an integer has more than 1 bit set */
 115
 116 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
 117
 118 /* Approximation of the length of the decimal representation of this type. */
 119 #define decimal_length(x)       ((int)(sizeof(x) * 2.56 + 0.5) + 1)
 120
 121 #if defined(__sun__)
 122  /*
 123   * On Solaris, when _XOPEN_EXTENDED is set, its header file
 124   * forces the programs to be XPG4v2, defeating any _XOPEN_SOURCE
 125   * setting to say we are XPG5 or XPG6.  Also on Solaris,
 126   * XPG6 programs must be compiled with a c99 compiler, while
 127   * non XPG6 programs must be compiled with a pre-c99 compiler.
 128   */
 129 # if __STDC_VERSION__ - 0 >= 199901L
 130 # define _XOPEN_SOURCE 600
 131 # else
 132 # define _XOPEN_SOURCE 500
 133 # endif
 134 #elif !defined(__APPLE__) && !defined(__FreeBSD__) && !defined(__USLC__) && \
 135       !defined(_M_UNIX) && !defined(__sgi) && !defined(__DragonFly__) && \
 136       !defined(__TANDEM) && !defined(__QNX__) && !defined(__MirBSD__) && \
 137       !defined(__CYGWIN__)
 138 #define _XOPEN_SOURCE 600 /* glibc2 and AIX 5.3L need 500, OpenBSD needs 600 for S_ISLNK() */
 139 #define _XOPEN_SOURCE_EXTENDED 1 /* AIX 5.3L needs this */
 140 #endif
 141 #define _ALL_SOURCE 1
 142 #define _GNU_SOURCE 1
 143 #define _BSD_SOURCE 1
 144 #define _DEFAULT_SOURCE 1
 145 #define _NETBSD_SOURCE 1
 146 #define _SGI_SOURCE 1
 147
 148 #if defined(WIN32) && !defined(__CYGWIN__) /* Both MinGW and MSVC */
 149 # if defined (_MSC_VER) && !defined(_WIN32_WINNT)
 150 #  define _WIN32_WINNT 0x0502
 151 # endif
 152 #define WIN32_LEAN_AND_MEAN  /* stops windows.h including winsock.h */
 153 #include <winsock2.h>
 154 #include <windows.h>
 155 #define GIT_WINDOWS_NATIVE
 156 #endif
 157
 158 #include <unistd.h>
 159 #include <stdio.h>
 160 #include <sys/stat.h>
 161 #include <fcntl.h>
 162 #include <stddef.h>
 163 #include <stdlib.h>
 164 #include <stdarg.h>
 165 #include <string.h>
 166 #ifdef HAVE_STRINGS_H
 167 #include <strings.h> /* for strcasecmp() */
 168 #endif
 169 #include <errno.h>
 170 #include <limits.h>
 171 #ifdef NEEDS_SYS_PARAM_H
 172 #include <sys/param.h>
 173 #endif
 174 #include <sys/types.h>
 175 #include <dirent.h>
 176 #include <sys/time.h>
 177 #include <time.h>
 178 #include <signal.h>
 179 #include <assert.h>
 180 #include <regex.h>
 181 #include <utime.h>
 182 #include <syslog.h>
 183 #ifndef NO_SYS_POLL_H
 184 #include <sys/poll.h>
 185 #else
 186 #include <poll.h>
 187 #endif
 188 #ifdef HAVE_BSD_SYSCTL
 189 #include <sys/sysctl.h>
 190 #endif
 191
 192 #if defined(__CYGWIN__)
 193 #include "compat/cygwin.h"
 194 #endif
 195 #if defined(__MINGW32__)
 196 /* pull in Windows compatibility stuff */
 197 #include "compat/mingw.h"
 198 #elif defined(_MSC_VER)
 199 #include "compat/msvc.h"
 200 #else
 201 #include <sys/utsname.h>
 202 #include <sys/wait.h>
 203 #include <sys/resource.h>
 204 #include <sys/socket.h>
 205 #include <sys/ioctl.h>
 206 #include <termios.h>
 207 #ifndef NO_SYS_SELECT_H
 208 #include <sys/select.h>
 209 #endif
 210 #include <netinet/in.h>
 211 #include <netinet/tcp.h>
 212 #include <arpa/inet.h>
 213 #include <netdb.h>
 214 #include <pwd.h>
 215 #include <sys/un.h>
 216 #ifndef NO_INTTYPES_H
 217 #include <inttypes.h>
 218 #else
 219 #include <stdint.h>
 220 #endif
 221 #ifdef NO_INTPTR_T
 222 /*
 223  * On I16LP32, ILP32 and LP64 "long" is the save bet, however
 224  * on LLP86, IL33LLP64 and P64 it needs to be "long long",
 225  * while on IP16 and IP16L32 it is "int" (resp. "short")
 226  * Size needs to match (or exceed) 'sizeof(void *)'.
 227  * We can't take "long long" here as not everybody has it.
 228  */
 229 typedef long intptr_t;
 230 typedef unsigned long uintptr_t;
 231 #endif
 232 #undef _ALL_SOURCE /* AIX 5.3L defines a struct list with _ALL_SOURCE. */
 233 #include <grp.h>
 234 #define _ALL_SOURCE 1
 235 #endif
 236
 237 /* used on Mac OS X */
 238 #ifdef PRECOMPOSE_UNICODE
 239 #include "compat/precompose_utf8.h"
 240 #else
 241 #define precompose_str(in,i_nfd2nfc)
 242 #define precompose_argv(c,v)
 243 #define probe_utf8_pathname_composition()
 244 #endif
 245
 246 #ifdef MKDIR_WO_TRAILING_SLASH
 247 #define mkdir(a,b) compat_mkdir_wo_trailing_slash((a),(b))
 248 extern int compat_mkdir_wo_trailing_slash(const char*, mode_t);
 249 #endif
 250
 251 #ifdef NO_STRUCT_ITIMERVAL
 252 struct itimerval {
 253         struct timeval it_interval;
 254         struct timeval it_value;
 255 };
 256 #endif
 257
 258 #ifdef NO_SETITIMER
 259 #define setitimer(which,value,ovalue)
 260 #endif
 261
 262 #ifndef NO_LIBGEN_H
 263 #include <libgen.h>
 264 #else
 265 #define basename gitbasename
 266 extern char *gitbasename(char *);
 267 #define dirname gitdirname
 268 extern char *gitdirname(char *);
 269 #endif
 270
 271 #ifndef NO_ICONV
 272 #include <iconv.h>
 273 #endif
 274
 275 #ifndef NO_OPENSSL
 276 #ifdef __APPLE__
 277 #define __AVAILABILITY_MACROS_USES_AVAILABILITY 0
 278 #include <AvailabilityMacros.h>
 279 #undef DEPRECATED_ATTRIBUTE
 280 #define DEPRECATED_ATTRIBUTE
 281 #undef __AVAILABILITY_MACROS_USES_AVAILABILITY
 282 #endif
 283 #include <openssl/ssl.h>
 284 #include <openssl/err.h>
 285 #endif
 286
 287 /* On most systems <netdb.h> would have given us this, but
 288  * not on some systems (e.g. z/OS).
 289  */
 290 #ifndef NI_MAXHOST
 291 #define NI_MAXHOST 1025
 292 #endif
 293
 294 #ifndef NI_MAXSERV
 295 #define NI_MAXSERV 32
 296 #endif
 297
 298 /* On most systems <limits.h> would have given us this, but
 299  * not on some systems (e.g. GNU/Hurd).
 300  */
 301 #ifndef PATH_MAX
 302 #define PATH_MAX 4096
 303 #endif
 304
 305 #ifndef PRIuMAX
 306 #define PRIuMAX "llu"
 307 #endif
 308
 309 #ifndef SCNuMAX
 310 #define SCNuMAX PRIuMAX
 311 #endif
 312
 313 #ifndef PRIu32
 314 #define PRIu32 "u"
 315 #endif
 316
 317 #ifndef PRIx32
 318 #define PRIx32 "x"
 319 #endif
 320
 321 #ifndef PRIo32
 322 #define PRIo32 "o"
 323 #endif
 324
 325 #ifndef PATH_SEP
 326 #define PATH_SEP ':'
 327 #endif
 328
 329 #ifdef HAVE_PATHS_H
 330 #include <paths.h>
 331 #endif
 332 #ifndef _PATH_DEFPATH
 333 #define _PATH_DEFPATH "/usr/local/bin:/usr/bin:/bin"
 334 #endif
 335
 336 #ifndef has_dos_drive_prefix
 337 static inline int git_has_dos_drive_prefix(const char *path)
 338 {
 339         return 0;
 340 }
 341 #define has_dos_drive_prefix git_has_dos_drive_prefix
 342 #endif
 343
 344 #ifndef skip_dos_drive_prefix
 345 static inline int git_skip_dos_drive_prefix(char **path)
 346 {
 347         return 0;
 348 }
 349 #define skip_dos_drive_prefix git_skip_dos_drive_prefix
 350 #endif
 351
 352 #ifndef is_dir_sep
 353 static inline int git_is_dir_sep(int c)
 354 {
 355         return c == '/';
 356 }
 357 #define is_dir_sep git_is_dir_sep
 358 #endif
 359
 360 #ifndef offset_1st_component
 361 static inline int git_offset_1st_component(const char *path)
 362 {
 363         return is_dir_sep(path[0]);
 364 }
 365 #define offset_1st_component git_offset_1st_component
 366 #endif
 367
 368 #ifndef find_last_dir_sep
 369 static inline char *git_find_last_dir_sep(const char *path)
 370 {
 371         return strrchr(path, '/');
 372 }
 373 #define find_last_dir_sep git_find_last_dir_sep
 374 #endif
 375
 376 #if defined(__HP_cc) && (__HP_cc >= 61000)
 377 #define NORETURN __attribute__((noreturn))
 378 #define NORETURN_PTR
 379 #elif defined(__GNUC__) && !defined(NO_NORETURN)
 380 #define NORETURN __attribute__((__noreturn__))
 381 #define NORETURN_PTR __attribute__((__noreturn__))
 382 #elif defined(_MSC_VER)
 383 #define NORETURN __declspec(noreturn)
 384 #define NORETURN_PTR
 385 #else
 386 #define NORETURN
 387 #define NORETURN_PTR
 388 #ifndef __GNUC__
 389 #ifndef __attribute__
 390 #define __attribute__(x)
 391 #endif
 392 #endif
 393 #endif
 394
 395 /* The sentinel attribute is valid from gcc version 4.0 */
 396 #if defined(__GNUC__) && (__GNUC__ >= 4)
 397 #define LAST_ARG_MUST_BE_NULL __attribute__((sentinel))
 398 #else
 399 #define LAST_ARG_MUST_BE_NULL
 400 #endif
 401
 402 #include "compat/bswap.h"
 403
 404 #include "wildmatch.h"
 405
 406 struct strbuf;
 407
 408 /* General helper functions */
 409 extern void vreportf(const char *prefix, const char *err, va_list params);
 410 extern NORETURN void usage(const char *err);
 411 extern NORETURN void usagef(const char *err, ...) __attribute__((format (printf, 1, 2)));
 412 extern NORETURN void die(const char *err, ...) __attribute__((format (printf, 1, 2)));
 413 extern NORETURN void die_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
 414 extern int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
 415 extern int error_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
 416 extern void warning(const char *err, ...) __attribute__((format (printf, 1, 2)));
 417 extern void warning_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
 418
 419 #ifndef NO_OPENSSL
 420 #ifdef APPLE_COMMON_CRYPTO
 421 #include "compat/apple-common-crypto.h"
 422 #else
 423 #include <openssl/evp.h>
 424 #include <openssl/hmac.h>
 425 #endif /* APPLE_COMMON_CRYPTO */
 426 #include <openssl/x509v3.h>
 427 #endif /* NO_OPENSSL */
 428
 429 /*
 430  * Let callers be aware of the constant return value; this can help
 431  * gcc with -Wuninitialized analysis. We restrict this trick to gcc, though,
 432  * because some compilers may not support variadic macros. Since we're only
 433  * trying to help gcc, anyway, it's OK; other compilers will fall back to
 434  * using the function as usual.
 435  */
 436 #if defined(__GNUC__)
 437 static inline int const_error(void)
 438 {
 439         return -1;
 440 }
 441 #define error(...) (error(__VA_ARGS__), const_error())
 442 #define error_errno(...) (error_errno(__VA_ARGS__), const_error())
 443 #endif
 444
 445 extern void set_die_routine(NORETURN_PTR void (*routine)(const char *err, va_list params));
 446 extern void set_error_routine(void (*routine)(const char *err, va_list params));
 447 extern void (*get_error_routine(void))(const char *err, va_list params);
 448 extern void set_warn_routine(void (*routine)(const char *warn, va_list params));
 449 extern void (*get_warn_routine(void))(const char *warn, va_list params);
 450 extern void set_die_is_recursing_routine(int (*routine)(void));
 451
 452 extern int starts_with(const char *str, const char *prefix);
 453
 454 /*
 455  * If the string "str" begins with the string found in "prefix", return 1.
 456  * The "out" parameter is set to "str + strlen(prefix)" (i.e., to the point in
 457  * the string right after the prefix).
 458  *
 459  * Otherwise, return 0 and leave "out" untouched.
 460  *
 461  * Examples:
 462  *
 463  *   [extract branch name, fail if not a branch]
 464  *   if (!skip_prefix(ref, "refs/heads/", &branch)
 465  *      return -1;
 466  *
 467  *   [skip prefix if present, otherwise use whole string]
 468  *   skip_prefix(name, "refs/heads/", &name);
 469  */
 470 static inline int skip_prefix(const char *str, const char *prefix,
 471                               const char **out)
 472 {
 473         do {
 474                 if (!*prefix) {
 475                         *out = str;
 476                         return 1;
 477                 }
 478         } while (*str++ == *prefix++);
 479         return 0;
 480 }
 481
 482 /*
 483  * Like skip_prefix, but promises never to read past "len" bytes of the input
 484  * buffer, and returns the remaining number of bytes in "out" via "outlen".
 485  */
 486 static inline int skip_prefix_mem(const char *buf, size_t len,
 487                                   const char *prefix,
 488                                   const char **out, size_t *outlen)
 489 {
 490         size_t prefix_len = strlen(prefix);
 491         if (prefix_len <= len && !memcmp(buf, prefix, prefix_len)) {
 492                 *out = buf + prefix_len;
 493                 *outlen = len - prefix_len;
 494                 return 1;
 495         }
 496         return 0;
 497 }
 498
 499 /*
 500  * If buf ends with suffix, return 1 and subtract the length of the suffix
 501  * from *len. Otherwise, return 0 and leave *len untouched.
 502  */
 503 static inline int strip_suffix_mem(const char *buf, size_t *len,
 504                                    const char *suffix)
 505 {
 506         size_t suflen = strlen(suffix);
 507         if (*len < suflen || memcmp(buf + (*len - suflen), suffix, suflen))
 508                 return 0;
 509         *len -= suflen;
 510         return 1;
 511 }
 512
 513 /*
 514  * If str ends with suffix, return 1 and set *len to the size of the string
 515  * without the suffix. Otherwise, return 0 and set *len to the size of the
 516  * string.
 517  *
 518  * Note that we do _not_ NUL-terminate str to the new length.
 519  */
 520 static inline int strip_suffix(const char *str, const char *suffix, size_t *len)
 521 {
 522         *len = strlen(str);
 523         return strip_suffix_mem(str, len, suffix);
 524 }
 525
 526 static inline int ends_with(const char *str, const char *suffix)
 527 {
 528         size_t len;
 529         return strip_suffix(str, suffix, &len);
 530 }
 531
 532 #define SWAP(a, b) do {                                         \
 533         void *_swap_a_ptr = &(a);                               \
 534         void *_swap_b_ptr = &(b);                               \
 535         unsigned char _swap_buffer[sizeof(a)];                  \
 536         memcpy(_swap_buffer, _swap_a_ptr, sizeof(a));           \
 537         memcpy(_swap_a_ptr, _swap_b_ptr, sizeof(a) +            \
 538                BUILD_ASSERT_OR_ZERO(sizeof(a) == sizeof(b)));   \
 539         memcpy(_swap_b_ptr, _swap_buffer, sizeof(a));           \
 540 } while (0)
 541
 542 #if defined(NO_MMAP) || defined(USE_WIN32_MMAP)
 543
 544 #ifndef PROT_READ
 545 #define PROT_READ 1
 546 #define PROT_WRITE 2
 547 #define MAP_PRIVATE 1
 548 #endif
 549
 550 #define mmap git_mmap
 551 #define munmap git_munmap
 552 extern void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset);
 553 extern int git_munmap(void *start, size_t length);
 554
 555 #else /* NO_MMAP || USE_WIN32_MMAP */
 556
 557 #include <sys/mman.h>
 558
 559 #endif /* NO_MMAP || USE_WIN32_MMAP */
 560
 561 #ifdef NO_MMAP
 562
 563 /* This value must be multiple of (pagesize * 2) */
 564 #define DEFAULT_PACKED_GIT_WINDOW_SIZE (1 * 1024 * 1024)
 565
 566 #else /* NO_MMAP */
 567
 568 /* This value must be multiple of (pagesize * 2) */
 569 #define DEFAULT_PACKED_GIT_WINDOW_SIZE \
 570         (sizeof(void*) >= 8 \
 571                 ?  1 * 1024 * 1024 * 1024 \
 572                 : 32 * 1024 * 1024)
 573
 574 #endif /* NO_MMAP */
 575
 576 #ifndef MAP_FAILED
 577 #define MAP_FAILED ((void *)-1)
 578 #endif
 579
 580 #ifdef NO_ST_BLOCKS_IN_STRUCT_STAT
 581 #define on_disk_bytes(st) ((st).st_size)
 582 #else
 583 #define on_disk_bytes(st) ((st).st_blocks * 512)
 584 #endif
 585
 586 #ifdef NEEDS_MODE_TRANSLATION
 587 #undef S_IFMT
 588 #undef S_IFREG
 589 #undef S_IFDIR
 590 #undef S_IFLNK
 591 #undef S_IFBLK
 592 #undef S_IFCHR
 593 #undef S_IFIFO
 594 #undef S_IFSOCK
 595 #define S_IFMT   0170000
 596 #define S_IFREG  0100000
 597 #define S_IFDIR  0040000
 598 #define S_IFLNK  0120000
 599 #define S_IFBLK  0060000
 600 #define S_IFCHR  0020000
 601 #define S_IFIFO  0010000
 602 #define S_IFSOCK 0140000
 603 #ifdef stat
 604 #undef stat
 605 #endif
 606 #define stat(path, buf) git_stat(path, buf)
 607 extern int git_stat(const char *, struct stat *);
 608 #ifdef fstat
 609 #undef fstat
 610 #endif
 611 #define fstat(fd, buf) git_fstat(fd, buf)
 612 extern int git_fstat(int, struct stat *);
 613 #ifdef lstat
 614 #undef lstat
 615 #endif
 616 #define lstat(path, buf) git_lstat(path, buf)
 617 extern int git_lstat(const char *, struct stat *);
 618 #endif
 619
 620 #define DEFAULT_PACKED_GIT_LIMIT \
 621         ((1024L * 1024L) * (size_t)(sizeof(void*) >= 8 ? 8192 : 256))
 622
 623 #ifdef NO_PREAD
 624 #define pread git_pread
 625 extern ssize_t git_pread(int fd, void *buf, size_t count, off_t offset);
 626 #endif
 627 /*
 628  * Forward decl that will remind us if its twin in cache.h changes.
 629  * This function is used in compat/pread.c.  But we can't include
 630  * cache.h there.
 631  */
 632 extern ssize_t read_in_full(int fd, void *buf, size_t count);
 633
 634 #ifdef NO_SETENV
 635 #define setenv gitsetenv
 636 extern int gitsetenv(const char *, const char *, int);
 637 #endif
 638
 639 #ifdef NO_MKDTEMP
 640 #define mkdtemp gitmkdtemp
 641 extern char *gitmkdtemp(char *);
 642 #endif
 643
 644 #ifdef NO_UNSETENV
 645 #define unsetenv gitunsetenv
 646 extern void gitunsetenv(const char *);
 647 #endif
 648
 649 #ifdef NO_STRCASESTR
 650 #define strcasestr gitstrcasestr
 651 extern char *gitstrcasestr(const char *haystack, const char *needle);
 652 #endif
 653
 654 #ifdef NO_STRLCPY
 655 #define strlcpy gitstrlcpy
 656 extern size_t gitstrlcpy(char *, const char *, size_t);
 657 #endif
 658
 659 #ifdef NO_STRTOUMAX
 660 #define strtoumax gitstrtoumax
 661 extern uintmax_t gitstrtoumax(const char *, char **, int);
 662 #define strtoimax gitstrtoimax
 663 extern intmax_t gitstrtoimax(const char *, char **, int);
 664 #endif
 665
 666 #ifdef NO_HSTRERROR
 667 #define hstrerror githstrerror
 668 extern const char *githstrerror(int herror);
 669 #endif
 670
 671 #ifdef NO_MEMMEM
 672 #define memmem gitmemmem
 673 void *gitmemmem(const void *haystack, size_t haystacklen,
 674                 const void *needle, size_t needlelen);
 675 #endif
 676
 677 #ifdef OVERRIDE_STRDUP
 678 #ifdef strdup
 679 #undef strdup
 680 #endif
 681 #define strdup gitstrdup
 682 char *gitstrdup(const char *s);
 683 #endif
 684
 685 #ifdef NO_GETPAGESIZE
 686 #define getpagesize() sysconf(_SC_PAGESIZE)
 687 #endif
 688
 689 #ifndef O_CLOEXEC
 690 #define O_CLOEXEC 0
 691 #endif
 692
 693 #ifdef FREAD_READS_DIRECTORIES
 694 #ifdef fopen
 695 #undef fopen
 696 #endif
 697 #define fopen(a,b) git_fopen(a,b)
 698 extern FILE *git_fopen(const char*, const char*);
 699 #endif
 700
 701 #ifdef SNPRINTF_RETURNS_BOGUS
 702 #ifdef snprintf
 703 #undef snprintf
 704 #endif
 705 #define snprintf git_snprintf
 706 extern int git_snprintf(char *str, size_t maxsize,
 707                         const char *format, ...);
 708 #ifdef vsnprintf
 709 #undef vsnprintf
 710 #endif
 711 #define vsnprintf git_vsnprintf
 712 extern int git_vsnprintf(char *str, size_t maxsize,
 713                          const char *format, va_list ap);
 714 #endif
 715
 716 #ifdef __GLIBC_PREREQ
 717 #if __GLIBC_PREREQ(2, 1)
 718 #define HAVE_STRCHRNUL
 719 #endif
 720 #endif
 721
 722 #ifndef HAVE_STRCHRNUL
 723 #define strchrnul gitstrchrnul
 724 static inline char *gitstrchrnul(const char *s, int c)
 725 {
 726         while (*s && *s != c)
 727                 s++;
 728         return (char *)s;
 729 }
 730 #endif
 731
 732 #ifdef NO_INET_PTON
 733 int inet_pton(int af, const char *src, void *dst);
 734 #endif
 735
 736 #ifdef NO_INET_NTOP
 737 const char *inet_ntop(int af, const void *src, char *dst, size_t size);
 738 #endif
 739
 740 #ifdef NO_PTHREADS
 741 #define atexit git_atexit
 742 extern int git_atexit(void (*handler)(void));
 743 #endif
 744
 745 extern void release_pack_memory(size_t);
 746
 747 typedef void (*try_to_free_t)(size_t);
 748 extern try_to_free_t set_try_to_free_routine(try_to_free_t);
 749
 750 static inline size_t st_add(size_t a, size_t b)
 751 {
 752         if (unsigned_add_overflows(a, b))
 753                 die("size_t overflow: %"PRIuMAX" + %"PRIuMAX,
 754                     (uintmax_t)a, (uintmax_t)b);
 755         return a + b;
 756 }
 757 #define st_add3(a,b,c)   st_add(st_add((a),(b)),(c))
 758 #define st_add4(a,b,c,d) st_add(st_add3((a),(b),(c)),(d))
 759
 760 static inline size_t st_mult(size_t a, size_t b)
 761 {
 762         if (unsigned_mult_overflows(a, b))
 763                 die("size_t overflow: %"PRIuMAX" * %"PRIuMAX,
 764                     (uintmax_t)a, (uintmax_t)b);
 765         return a * b;
 766 }
 767
 768 static inline size_t st_sub(size_t a, size_t b)
 769 {
 770         if (a < b)
 771                 die("size_t underflow: %"PRIuMAX" - %"PRIuMAX,
 772                     (uintmax_t)a, (uintmax_t)b);
 773         return a - b;
 774 }
 775
 776 #ifdef HAVE_ALLOCA_H
 777 # include <alloca.h>
 778 # define xalloca(size)      (alloca(size))
 779 # define xalloca_free(p)    do {} while (0)
 780 #else
 781 # define xalloca(size)      (xmalloc(size))
 782 # define xalloca_free(p)    (free(p))
 783 #endif
 784 extern char *xstrdup(const char *str);
 785 extern void *xmalloc(size_t size);
 786 extern void *xmallocz(size_t size);
 787 extern void *xmallocz_gently(size_t size);
 788 extern void *xmemdupz(const void *data, size_t len);
 789 extern char *xstrndup(const char *str, size_t len);
 790 extern void *xrealloc(void *ptr, size_t size);
 791 extern void *xcalloc(size_t nmemb, size_t size);
 792 extern void *xmmap(void *start, size_t length, int prot, int flags, int fd, off_t offset);
 793 extern void *xmmap_gently(void *start, size_t length, int prot, int flags, int fd, off_t offset);
 794 extern int xopen(const char *path, int flags, ...);
 795 extern ssize_t xread(int fd, void *buf, size_t len);
 796 extern ssize_t xwrite(int fd, const void *buf, size_t len);
 797 extern ssize_t xpread(int fd, void *buf, size_t len, off_t offset);
 798 extern int xdup(int fd);
 799 extern FILE *xfopen(const char *path, const char *mode);
 800 extern FILE *xfdopen(int fd, const char *mode);
 801 extern int xmkstemp(char *template);
 802 extern int xmkstemp_mode(char *template, int mode);
 803 extern char *xgetcwd(void);
 804 extern FILE *fopen_for_writing(const char *path);
 805
 806 #define ALLOC_ARRAY(x, alloc) (x) = xmalloc(st_mult(sizeof(*(x)), (alloc)))
 807 #define REALLOC_ARRAY(x, alloc) (x) = xrealloc((x), st_mult(sizeof(*(x)), (alloc)))
 808
 809 #define COPY_ARRAY(dst, src, n) copy_array((dst), (src), (n), sizeof(*(dst)) + \
 810         BUILD_ASSERT_OR_ZERO(sizeof(*(dst)) == sizeof(*(src))))
 811 static inline void copy_array(void *dst, const void *src, size_t n, size_t size)
 812 {
 813         if (n)
 814                 memcpy(dst, src, st_mult(size, n));
 815 }
 816
 817 /*
 818  * These functions help you allocate structs with flex arrays, and copy
 819  * the data directly into the array. For example, if you had:
 820  *
 821  *   struct foo {
 822  *     int bar;
 823  *     char name[FLEX_ARRAY];
 824  *   };
 825  *
 826  * you can do:
 827  *
 828  *   struct foo *f;
 829  *   FLEX_ALLOC_MEM(f, name, src, len);
 830  *
 831  * to allocate a "foo" with the contents of "src" in the "name" field.
 832  * The resulting struct is automatically zero'd, and the flex-array field
 833  * is NUL-terminated (whether the incoming src buffer was or not).
 834  *
 835  * The FLEXPTR_* variants operate on structs that don't use flex-arrays,
 836  * but do want to store a pointer to some extra data in the same allocated
 837  * block. For example, if you have:
 838  *
 839  *   struct foo {
 840  *     char *name;
 841  *     int bar;
 842  *   };
 843  *
 844  * you can do:
 845  *
 846  *   struct foo *f;
 847  *   FLEXPTR_ALLOC_STR(f, name, src);
 848  *
 849  * and "name" will point to a block of memory after the struct, which will be
 850  * freed along with the struct (but the pointer can be repointed anywhere).
 851  *
 852  * The *_STR variants accept a string parameter rather than a ptr/len
 853  * combination.
 854  *
 855  * Note that these macros will evaluate the first parameter multiple
 856  * times, and it must be assignable as an lvalue.
 857  */
 858 #define FLEX_ALLOC_MEM(x, flexname, buf, len) do { \
 859         size_t flex_array_len_ = (len); \
 860         (x) = xcalloc(1, st_add3(sizeof(*(x)), flex_array_len_, 1)); \
 861         memcpy((void *)(x)->flexname, (buf), flex_array_len_); \
 862 } while (0)
 863 #define FLEXPTR_ALLOC_MEM(x, ptrname, buf, len) do { \
 864         size_t flex_array_len_ = (len); \
 865         (x) = xcalloc(1, st_add3(sizeof(*(x)), flex_array_len_, 1)); \
 866         memcpy((x) + 1, (buf), flex_array_len_); \
 867         (x)->ptrname = (void *)((x)+1); \
 868 } while(0)
 869 #define FLEX_ALLOC_STR(x, flexname, str) \
 870         FLEX_ALLOC_MEM((x), flexname, (str), strlen(str))
 871 #define FLEXPTR_ALLOC_STR(x, ptrname, str) \
 872         FLEXPTR_ALLOC_MEM((x), ptrname, (str), strlen(str))
 873
 874 static inline char *xstrdup_or_null(const char *str)
 875 {
 876         return str ? xstrdup(str) : NULL;
 877 }
 878
 879 static inline size_t xsize_t(off_t len)
 880 {
 881         if (len > (size_t) len)
 882                 die("Cannot handle files this big");
 883         return (size_t)len;
 884 }
 885
 886 __attribute__((format (printf, 3, 4)))
 887 extern int xsnprintf(char *dst, size_t max, const char *fmt, ...);
 888
 889 #ifndef HOST_NAME_MAX
 890 #define HOST_NAME_MAX 256
 891 #endif
 892
 893 extern int xgethostname(char *buf, size_t len);
 894
 895 /* in ctype.c, for kwset users */
 896 extern const unsigned char tolower_trans_tbl[256];
 897
 898 /* Sane ctype - no locale, and works with signed chars */
 899 #undef isascii
 900 #undef isspace
 901 #undef isdigit
 902 #undef isalpha
 903 #undef isalnum
 904 #undef isprint
 905 #undef islower
 906 #undef isupper
 907 #undef tolower
 908 #undef toupper
 909 #undef iscntrl
 910 #undef ispunct
 911 #undef isxdigit
 912
 913 extern const unsigned char sane_ctype[256];
 914 #define GIT_SPACE 0x01
 915 #define GIT_DIGIT 0x02
 916 #define GIT_ALPHA 0x04
 917 #define GIT_GLOB_SPECIAL 0x08
 918 #define GIT_REGEX_SPECIAL 0x10
 919 #define GIT_PATHSPEC_MAGIC 0x20
 920 #define GIT_CNTRL 0x40
 921 #define GIT_PUNCT 0x80
 922 #define sane_istest(x,mask) ((sane_ctype[(unsigned char)(x)] & (mask)) != 0)
 923 #define isascii(x) (((x) & ~0x7f) == 0)
 924 #define isspace(x) sane_istest(x,GIT_SPACE)
 925 #define isdigit(x) sane_istest(x,GIT_DIGIT)
 926 #define isalpha(x) sane_istest(x,GIT_ALPHA)
 927 #define isalnum(x) sane_istest(x,GIT_ALPHA | GIT_DIGIT)
 928 #define isprint(x) ((x) >= 0x20 && (x) <= 0x7e)
 929 #define islower(x) sane_iscase(x, 1)
 930 #define isupper(x) sane_iscase(x, 0)
 931 #define is_glob_special(x) sane_istest(x,GIT_GLOB_SPECIAL)
 932 #define is_regex_special(x) sane_istest(x,GIT_GLOB_SPECIAL | GIT_REGEX_SPECIAL)
 933 #define iscntrl(x) (sane_istest(x,GIT_CNTRL))
 934 #define ispunct(x) sane_istest(x, GIT_PUNCT | GIT_REGEX_SPECIAL | \
 935                 GIT_GLOB_SPECIAL | GIT_PATHSPEC_MAGIC)
 936 #define isxdigit(x) (hexval_table[(unsigned char)(x)] != -1)
 937 #define tolower(x) sane_case((unsigned char)(x), 0x20)
 938 #define toupper(x) sane_case((unsigned char)(x), 0)
 939 #define is_pathspec_magic(x) sane_istest(x,GIT_PATHSPEC_MAGIC)
 940
 941 static inline int sane_case(int x, int high)
 942 {
 943         if (sane_istest(x, GIT_ALPHA))
 944                 x = (x & ~0x20) | high;
 945         return x;
 946 }
 947
 948 static inline int sane_iscase(int x, int is_lower)
 949 {
 950         if (!sane_istest(x, GIT_ALPHA))
 951                 return 0;
 952
 953         if (is_lower)
 954                 return (x & 0x20) != 0;
 955         else
 956                 return (x & 0x20) == 0;
 957 }
 958
 959 static inline int strtoul_ui(char const *s, int base, unsigned int *result)
 960 {
 961         unsigned long ul;
 962         char *p;
 963
 964         errno = 0;
 965         /* negative values would be accepted by strtoul */
 966         if (strchr(s, '-'))
 967                 return -1;
 968         ul = strtoul(s, &p, base);
 969         if (errno || *p || p == s || (unsigned int) ul != ul)
 970                 return -1;
 971         *result = ul;
 972         return 0;
 973 }
 974
 975 static inline int strtol_i(char const *s, int base, int *result)
 976 {
 977         long ul;
 978         char *p;
 979
 980         errno = 0;
 981         ul = strtol(s, &p, base);
 982         if (errno || *p || p == s || (int) ul != ul)
 983                 return -1;
 984         *result = ul;
 985         return 0;
 986 }
 987
 988 #ifdef INTERNAL_QSORT
 989 void git_qsort(void *base, size_t nmemb, size_t size,
 990                int(*compar)(const void *, const void *));
 991 #define qsort git_qsort
 992 #endif
 993
 994 #define QSORT(base, n, compar) sane_qsort((base), (n), sizeof(*(base)), compar)
 995 static inline void sane_qsort(void *base, size_t nmemb, size_t size,
 996                               int(*compar)(const void *, const void *))
 997 {
 998         if (nmemb > 1)
 999                 qsort(base, nmemb, size, compar);
1000 }
1001
1002 #ifndef HAVE_ISO_QSORT_S
1003 int git_qsort_s(void *base, size_t nmemb, size_t size,
1004                 int (*compar)(const void *, const void *, void *), void *ctx);
1005 #define qsort_s git_qsort_s
1006 #endif
1007
1008 #define QSORT_S(base, n, compar, ctx) do {                      \
1009         if (qsort_s((base), (n), sizeof(*(base)), compar, ctx)) \
1010                 die("BUG: qsort_s() failed");                   \
1011 } while (0)
1012
1013 #ifndef REG_STARTEND
1014 #error "Git requires REG_STARTEND support. Compile with NO_REGEX=NeedsStartEnd"
1015 #endif
1016
1017 static inline int regexec_buf(const regex_t *preg, const char *buf, size_t size,
1018                               size_t nmatch, regmatch_t pmatch[], int eflags)
1019 {
1020         assert(nmatch > 0 && pmatch);
1021         pmatch[0].rm_so = 0;
1022         pmatch[0].rm_eo = size;
1023         return regexec(preg, buf, nmatch, pmatch, eflags | REG_STARTEND);
1024 }
1025
1026 #ifndef DIR_HAS_BSD_GROUP_SEMANTICS
1027 # define FORCE_DIR_SET_GID S_ISGID
1028 #else
1029 # define FORCE_DIR_SET_GID 0
1030 #endif
1031
1032 #ifdef NO_NSEC
1033 #undef USE_NSEC
1034 #define ST_CTIME_NSEC(st) 0
1035 #define ST_MTIME_NSEC(st) 0
1036 #else
1037 #ifdef USE_ST_TIMESPEC
1038 #define ST_CTIME_NSEC(st) ((unsigned int)((st).st_ctimespec.tv_nsec))
1039 #define ST_MTIME_NSEC(st) ((unsigned int)((st).st_mtimespec.tv_nsec))
1040 #else
1041 #define ST_CTIME_NSEC(st) ((unsigned int)((st).st_ctim.tv_nsec))
1042 #define ST_MTIME_NSEC(st) ((unsigned int)((st).st_mtim.tv_nsec))
1043 #endif
1044 #endif
1045
1046 #ifdef UNRELIABLE_FSTAT
1047 #define fstat_is_reliable() 0
1048 #else
1049 #define fstat_is_reliable() 1
1050 #endif
1051
1052 #ifndef va_copy
1053 /*
1054  * Since an obvious implementation of va_list would be to make it a
1055  * pointer into the stack frame, a simple assignment will work on
1056  * many systems.  But let's try to be more portable.
1057  */
1058 #ifdef __va_copy
1059 #define va_copy(dst, src) __va_copy(dst, src)
1060 #else
1061 #define va_copy(dst, src) ((dst) = (src))
1062 #endif
1063 #endif
1064
1065 #if defined(__GNUC__) || (_MSC_VER >= 1400) || defined(__C99_MACRO_WITH_VA_ARGS)
1066 #define HAVE_VARIADIC_MACROS 1
1067 #endif
1068
1069 #ifdef HAVE_VARIADIC_MACROS
1070 __attribute__((format (printf, 3, 4))) NORETURN
1071 void BUG_fl(const char *file, int line, const char *fmt, ...);
1072 #define BUG(...) BUG_fl(__FILE__, __LINE__, __VA_ARGS__)
1073 #else
1074 __attribute__((format (printf, 1, 2))) NORETURN
1075 void BUG(const char *fmt, ...);
1076 #endif
1077
1078 /*
1079  * Preserves errno, prints a message, but gives no warning for ENOENT.
1080  * Returns 0 on success, which includes trying to unlink an object that does
1081  * not exist.
1082  */
1083 int unlink_or_warn(const char *path);
1084  /*
1085   * Tries to unlink file.  Returns 0 if unlink succeeded
1086   * or the file already didn't exist.  Returns -1 and
1087   * appends a message to err suitable for
1088   * 'error("%s", err->buf)' on error.
1089   */
1090 int unlink_or_msg(const char *file, struct strbuf *err);
1091 /*
1092  * Preserves errno, prints a message, but gives no warning for ENOENT.
1093  * Returns 0 on success, which includes trying to remove a directory that does
1094  * not exist.
1095  */
1096 int rmdir_or_warn(const char *path);
1097 /*
1098  * Calls the correct function out of {unlink,rmdir}_or_warn based on
1099  * the supplied file mode.
1100  */
1101 int remove_or_warn(unsigned int mode, const char *path);
1102
1103 /*
1104  * Call access(2), but warn for any error except "missing file"
1105  * (ENOENT or ENOTDIR).
1106  */
1107 #define ACCESS_EACCES_OK (1U << 0)
1108 int access_or_warn(const char *path, int mode, unsigned flag);
1109 int access_or_die(const char *path, int mode, unsigned flag);
1110
1111 /* Warn on an inaccessible file that ought to be accessible */
1112 void warn_on_inaccessible(const char *path);
1113
1114 #ifdef GMTIME_UNRELIABLE_ERRORS
1115 struct tm *git_gmtime(const time_t *);
1116 struct tm *git_gmtime_r(const time_t *, struct tm *);
1117 #define gmtime git_gmtime
1118 #define gmtime_r git_gmtime_r
1119 #endif
1120
1121 #if !defined(USE_PARENS_AROUND_GETTEXT_N) && defined(__GNUC__)
1122 #define USE_PARENS_AROUND_GETTEXT_N 1
1123 #endif
1124
1125 #ifndef SHELL_PATH
1126 # define SHELL_PATH "/bin/sh"
1127 #endif
1128
1129 #ifndef _POSIX_THREAD_SAFE_FUNCTIONS
1130 #define flockfile(fh)
1131 #define funlockfile(fh)
1132 #define getc_unlocked(fh) getc(fh)
1133 #endif
1134
1135 extern int cmd_main(int, const char **);
1136
1137 #endif