add helpers for allocating flex-array structs
[git/git-svn.git] / git-compat-util.h
blob57ff9fb19afc2f9d1d96aeef378c77d2475b92f2
1 #ifndef GIT_COMPAT_UTIL_H
2 #define GIT_COMPAT_UTIL_H
4 #define _FILE_OFFSET_BITS 64
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
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
23 #ifndef FLEX_ARRAY
25 * See if our compiler is known to support flexible array members.
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
38 * Otherwise, default to safer but a bit wasteful traditional style
40 #ifndef FLEX_ARRAY
41 # define FLEX_ARRAY 1
42 #endif
43 #endif
47 * BUILD_ASSERT_OR_ZERO - assert a build-time dependency, as an expression.
48 * @cond: the compile-time condition which must be true.
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".
53 * Example:
54 * #define foo_to_char(foo) \
55 * ((char *)(foo) \
56 * + BUILD_ASSERT_OR_ZERO(offsetof(struct foo, string) == 0))
58 #define BUILD_ASSERT_OR_ZERO(cond) \
59 (sizeof(char [1 - 2*!(cond)]) - 1)
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
70 * ARRAY_SIZE - get the number of elements in a visible array
71 * <at> x: the array whose size you want.
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).
77 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]) + BARF_UNLESS_AN_ARRAY(x))
79 #define bitsizeof(x) (CHAR_BIT * sizeof(x))
81 #define maximum_signed_value_of_type(a) \
82 (INTMAX_MAX >> (bitsizeof(intmax_t) - bitsizeof(a)))
84 #define maximum_unsigned_value_of_type(a) \
85 (UINTMAX_MAX >> (bitsizeof(uintmax_t) - bitsizeof(a)))
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.
91 * Requires: a >= 0, typeof(a) equals typeof(b)
93 #define signed_add_overflows(a, b) \
94 ((b) > maximum_signed_value_of_type(a) - (a))
96 #define unsigned_add_overflows(a, b) \
97 ((b) > maximum_unsigned_value_of_type(a) - (a))
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!
104 #define unsigned_mult_overflows(a, b) \
105 ((a) && (b) > maximum_unsigned_value_of_type(a) / (a))
107 #ifdef __GNUC__
108 #define TYPEOF(x) (__typeof__(x))
109 #else
110 #define TYPEOF(x)
111 #endif
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 */
116 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
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)
121 #if defined(__sun__)
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.
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
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
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
192 #if defined(__MINGW32__)
193 /* pull in Windows compatibility stuff */
194 #include "compat/mingw.h"
195 #elif defined(_MSC_VER)
196 #include "compat/msvc.h"
197 #else
198 #include <sys/utsname.h>
199 #include <sys/wait.h>
200 #include <sys/resource.h>
201 #include <sys/socket.h>
202 #include <sys/ioctl.h>
203 #include <termios.h>
204 #ifndef NO_SYS_SELECT_H
205 #include <sys/select.h>
206 #endif
207 #include <netinet/in.h>
208 #include <netinet/tcp.h>
209 #include <arpa/inet.h>
210 #include <netdb.h>
211 #include <pwd.h>
212 #include <sys/un.h>
213 #ifndef NO_INTTYPES_H
214 #include <inttypes.h>
215 #else
216 #include <stdint.h>
217 #endif
218 #ifdef NO_INTPTR_T
220 * On I16LP32, ILP32 and LP64 "long" is the save bet, however
221 * on LLP86, IL33LLP64 and P64 it needs to be "long long",
222 * while on IP16 and IP16L32 it is "int" (resp. "short")
223 * Size needs to match (or exceed) 'sizeof(void *)'.
224 * We can't take "long long" here as not everybody has it.
226 typedef long intptr_t;
227 typedef unsigned long uintptr_t;
228 #endif
229 #undef _ALL_SOURCE /* AIX 5.3L defines a struct list with _ALL_SOURCE. */
230 #include <grp.h>
231 #define _ALL_SOURCE 1
232 #endif
234 /* used on Mac OS X */
235 #ifdef PRECOMPOSE_UNICODE
236 #include "compat/precompose_utf8.h"
237 #else
238 #define precompose_str(in,i_nfd2nfc)
239 #define precompose_argv(c,v)
240 #define probe_utf8_pathname_composition()
241 #endif
243 #ifdef MKDIR_WO_TRAILING_SLASH
244 #define mkdir(a,b) compat_mkdir_wo_trailing_slash((a),(b))
245 extern int compat_mkdir_wo_trailing_slash(const char*, mode_t);
246 #endif
248 #ifdef NO_STRUCT_ITIMERVAL
249 struct itimerval {
250 struct timeval it_interval;
251 struct timeval it_value;
253 #endif
255 #ifdef NO_SETITIMER
256 #define setitimer(which,value,ovalue)
257 #endif
259 #ifndef NO_LIBGEN_H
260 #include <libgen.h>
261 #else
262 #define basename gitbasename
263 extern char *gitbasename(char *);
264 #define dirname gitdirname
265 extern char *gitdirname(char *);
266 #endif
268 #ifndef NO_ICONV
269 #include <iconv.h>
270 #endif
272 #ifndef NO_OPENSSL
273 #ifdef __APPLE__
274 #define __AVAILABILITY_MACROS_USES_AVAILABILITY 0
275 #include <AvailabilityMacros.h>
276 #undef DEPRECATED_ATTRIBUTE
277 #define DEPRECATED_ATTRIBUTE
278 #undef __AVAILABILITY_MACROS_USES_AVAILABILITY
279 #endif
280 #include <openssl/ssl.h>
281 #include <openssl/err.h>
282 #ifdef NO_HMAC_CTX_CLEANUP
283 #define HMAC_CTX_cleanup HMAC_cleanup
284 #endif
285 #endif
287 /* On most systems <netdb.h> would have given us this, but
288 * not on some systems (e.g. z/OS).
290 #ifndef NI_MAXHOST
291 #define NI_MAXHOST 1025
292 #endif
294 #ifndef NI_MAXSERV
295 #define NI_MAXSERV 32
296 #endif
298 /* On most systems <limits.h> would have given us this, but
299 * not on some systems (e.g. GNU/Hurd).
301 #ifndef PATH_MAX
302 #define PATH_MAX 4096
303 #endif
305 #ifndef PRIuMAX
306 #define PRIuMAX "llu"
307 #endif
309 #ifndef SCNuMAX
310 #define SCNuMAX PRIuMAX
311 #endif
313 #ifndef PRIu32
314 #define PRIu32 "u"
315 #endif
317 #ifndef PRIx32
318 #define PRIx32 "x"
319 #endif
321 #ifndef PRIo32
322 #define PRIo32 "o"
323 #endif
325 #ifndef PATH_SEP
326 #define PATH_SEP ':'
327 #endif
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
336 #ifndef STRIP_EXTENSION
337 #define STRIP_EXTENSION ""
338 #endif
340 #ifndef has_dos_drive_prefix
341 static inline int git_has_dos_drive_prefix(const char *path)
343 return 0;
345 #define has_dos_drive_prefix git_has_dos_drive_prefix
346 #endif
348 #ifndef skip_dos_drive_prefix
349 static inline int git_skip_dos_drive_prefix(char **path)
351 return 0;
353 #define skip_dos_drive_prefix git_skip_dos_drive_prefix
354 #endif
356 #ifndef is_dir_sep
357 static inline int git_is_dir_sep(int c)
359 return c == '/';
361 #define is_dir_sep git_is_dir_sep
362 #endif
364 #ifndef offset_1st_component
365 static inline int git_offset_1st_component(const char *path)
367 return is_dir_sep(path[0]);
369 #define offset_1st_component git_offset_1st_component
370 #endif
372 #ifndef find_last_dir_sep
373 static inline char *git_find_last_dir_sep(const char *path)
375 return strrchr(path, '/');
377 #define find_last_dir_sep git_find_last_dir_sep
378 #endif
380 #if defined(__HP_cc) && (__HP_cc >= 61000)
381 #define NORETURN __attribute__((noreturn))
382 #define NORETURN_PTR
383 #elif defined(__GNUC__) && !defined(NO_NORETURN)
384 #define NORETURN __attribute__((__noreturn__))
385 #define NORETURN_PTR __attribute__((__noreturn__))
386 #elif defined(_MSC_VER)
387 #define NORETURN __declspec(noreturn)
388 #define NORETURN_PTR
389 #else
390 #define NORETURN
391 #define NORETURN_PTR
392 #ifndef __GNUC__
393 #ifndef __attribute__
394 #define __attribute__(x)
395 #endif
396 #endif
397 #endif
399 /* The sentinel attribute is valid from gcc version 4.0 */
400 #if defined(__GNUC__) && (__GNUC__ >= 4)
401 #define LAST_ARG_MUST_BE_NULL __attribute__((sentinel))
402 #else
403 #define LAST_ARG_MUST_BE_NULL
404 #endif
406 #include "compat/bswap.h"
408 #include "wildmatch.h"
410 struct strbuf;
412 /* General helper functions */
413 extern void vreportf(const char *prefix, const char *err, va_list params);
414 extern NORETURN void usage(const char *err);
415 extern NORETURN void usagef(const char *err, ...) __attribute__((format (printf, 1, 2)));
416 extern NORETURN void die(const char *err, ...) __attribute__((format (printf, 1, 2)));
417 extern NORETURN void die_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
418 extern int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
419 extern void warning(const char *err, ...) __attribute__((format (printf, 1, 2)));
421 #ifndef NO_OPENSSL
422 #ifdef APPLE_COMMON_CRYPTO
423 #include "compat/apple-common-crypto.h"
424 #else
425 #include <openssl/evp.h>
426 #include <openssl/hmac.h>
427 #endif /* APPLE_COMMON_CRYPTO */
428 #include <openssl/x509v3.h>
429 #endif /* NO_OPENSSL */
432 * Let callers be aware of the constant return value; this can help
433 * gcc with -Wuninitialized analysis. We restrict this trick to gcc, though,
434 * because some compilers may not support variadic macros. Since we're only
435 * trying to help gcc, anyway, it's OK; other compilers will fall back to
436 * using the function as usual.
438 #if defined(__GNUC__)
439 static inline int const_error(void)
441 return -1;
443 #define error(...) (error(__VA_ARGS__), const_error())
444 #endif
446 extern void set_die_routine(NORETURN_PTR void (*routine)(const char *err, va_list params));
447 extern void set_error_routine(void (*routine)(const char *err, va_list params));
448 extern void set_die_is_recursing_routine(int (*routine)(void));
449 extern void set_error_handle(FILE *);
451 extern int starts_with(const char *str, const char *prefix);
454 * If the string "str" begins with the string found in "prefix", return 1.
455 * The "out" parameter is set to "str + strlen(prefix)" (i.e., to the point in
456 * the string right after the prefix).
458 * Otherwise, return 0 and leave "out" untouched.
460 * Examples:
462 * [extract branch name, fail if not a branch]
463 * if (!skip_prefix(ref, "refs/heads/", &branch)
464 * return -1;
466 * [skip prefix if present, otherwise use whole string]
467 * skip_prefix(name, "refs/heads/", &name);
469 static inline int skip_prefix(const char *str, const char *prefix,
470 const char **out)
472 do {
473 if (!*prefix) {
474 *out = str;
475 return 1;
477 } while (*str++ == *prefix++);
478 return 0;
482 * If buf ends with suffix, return 1 and subtract the length of the suffix
483 * from *len. Otherwise, return 0 and leave *len untouched.
485 static inline int strip_suffix_mem(const char *buf, size_t *len,
486 const char *suffix)
488 size_t suflen = strlen(suffix);
489 if (*len < suflen || memcmp(buf + (*len - suflen), suffix, suflen))
490 return 0;
491 *len -= suflen;
492 return 1;
496 * If str ends with suffix, return 1 and set *len to the size of the string
497 * without the suffix. Otherwise, return 0 and set *len to the size of the
498 * string.
500 * Note that we do _not_ NUL-terminate str to the new length.
502 static inline int strip_suffix(const char *str, const char *suffix, size_t *len)
504 *len = strlen(str);
505 return strip_suffix_mem(str, len, suffix);
508 static inline int ends_with(const char *str, const char *suffix)
510 size_t len;
511 return strip_suffix(str, suffix, &len);
514 #if defined(NO_MMAP) || defined(USE_WIN32_MMAP)
516 #ifndef PROT_READ
517 #define PROT_READ 1
518 #define PROT_WRITE 2
519 #define MAP_PRIVATE 1
520 #endif
522 #define mmap git_mmap
523 #define munmap git_munmap
524 extern void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset);
525 extern int git_munmap(void *start, size_t length);
527 #else /* NO_MMAP || USE_WIN32_MMAP */
529 #include <sys/mman.h>
531 #endif /* NO_MMAP || USE_WIN32_MMAP */
533 #ifdef NO_MMAP
535 /* This value must be multiple of (pagesize * 2) */
536 #define DEFAULT_PACKED_GIT_WINDOW_SIZE (1 * 1024 * 1024)
538 #else /* NO_MMAP */
540 /* This value must be multiple of (pagesize * 2) */
541 #define DEFAULT_PACKED_GIT_WINDOW_SIZE \
542 (sizeof(void*) >= 8 \
543 ? 1 * 1024 * 1024 * 1024 \
544 : 32 * 1024 * 1024)
546 #endif /* NO_MMAP */
548 #ifndef MAP_FAILED
549 #define MAP_FAILED ((void *)-1)
550 #endif
552 #ifdef NO_ST_BLOCKS_IN_STRUCT_STAT
553 #define on_disk_bytes(st) ((st).st_size)
554 #else
555 #define on_disk_bytes(st) ((st).st_blocks * 512)
556 #endif
558 #ifdef NEEDS_MODE_TRANSLATION
559 #undef S_IFMT
560 #undef S_IFREG
561 #undef S_IFDIR
562 #undef S_IFLNK
563 #undef S_IFBLK
564 #undef S_IFCHR
565 #undef S_IFIFO
566 #undef S_IFSOCK
567 #define S_IFMT 0170000
568 #define S_IFREG 0100000
569 #define S_IFDIR 0040000
570 #define S_IFLNK 0120000
571 #define S_IFBLK 0060000
572 #define S_IFCHR 0020000
573 #define S_IFIFO 0010000
574 #define S_IFSOCK 0140000
575 #ifdef stat
576 #undef stat
577 #endif
578 #define stat(path, buf) git_stat(path, buf)
579 extern int git_stat(const char *, struct stat *);
580 #ifdef fstat
581 #undef fstat
582 #endif
583 #define fstat(fd, buf) git_fstat(fd, buf)
584 extern int git_fstat(int, struct stat *);
585 #ifdef lstat
586 #undef lstat
587 #endif
588 #define lstat(path, buf) git_lstat(path, buf)
589 extern int git_lstat(const char *, struct stat *);
590 #endif
592 #define DEFAULT_PACKED_GIT_LIMIT \
593 ((1024L * 1024L) * (size_t)(sizeof(void*) >= 8 ? 8192 : 256))
595 #ifdef NO_PREAD
596 #define pread git_pread
597 extern ssize_t git_pread(int fd, void *buf, size_t count, off_t offset);
598 #endif
600 * Forward decl that will remind us if its twin in cache.h changes.
601 * This function is used in compat/pread.c. But we can't include
602 * cache.h there.
604 extern ssize_t read_in_full(int fd, void *buf, size_t count);
606 #ifdef NO_SETENV
607 #define setenv gitsetenv
608 extern int gitsetenv(const char *, const char *, int);
609 #endif
611 #ifdef NO_MKDTEMP
612 #define mkdtemp gitmkdtemp
613 extern char *gitmkdtemp(char *);
614 #endif
616 #ifdef NO_MKSTEMPS
617 #define mkstemps gitmkstemps
618 extern int gitmkstemps(char *, int);
619 #endif
621 #ifdef NO_UNSETENV
622 #define unsetenv gitunsetenv
623 extern void gitunsetenv(const char *);
624 #endif
626 #ifdef NO_STRCASESTR
627 #define strcasestr gitstrcasestr
628 extern char *gitstrcasestr(const char *haystack, const char *needle);
629 #endif
631 #ifdef NO_STRLCPY
632 #define strlcpy gitstrlcpy
633 extern size_t gitstrlcpy(char *, const char *, size_t);
634 #endif
636 #ifdef NO_STRTOUMAX
637 #define strtoumax gitstrtoumax
638 extern uintmax_t gitstrtoumax(const char *, char **, int);
639 #define strtoimax gitstrtoimax
640 extern intmax_t gitstrtoimax(const char *, char **, int);
641 #endif
643 #ifdef NO_HSTRERROR
644 #define hstrerror githstrerror
645 extern const char *githstrerror(int herror);
646 #endif
648 #ifdef NO_MEMMEM
649 #define memmem gitmemmem
650 void *gitmemmem(const void *haystack, size_t haystacklen,
651 const void *needle, size_t needlelen);
652 #endif
654 #ifdef NO_GETPAGESIZE
655 #define getpagesize() sysconf(_SC_PAGESIZE)
656 #endif
658 #ifdef FREAD_READS_DIRECTORIES
659 #ifdef fopen
660 #undef fopen
661 #endif
662 #define fopen(a,b) git_fopen(a,b)
663 extern FILE *git_fopen(const char*, const char*);
664 #endif
666 #ifdef SNPRINTF_RETURNS_BOGUS
667 #ifdef snprintf
668 #undef snprintf
669 #endif
670 #define snprintf git_snprintf
671 extern int git_snprintf(char *str, size_t maxsize,
672 const char *format, ...);
673 #ifdef vsnprintf
674 #undef vsnprintf
675 #endif
676 #define vsnprintf git_vsnprintf
677 extern int git_vsnprintf(char *str, size_t maxsize,
678 const char *format, va_list ap);
679 #endif
681 #ifdef __GLIBC_PREREQ
682 #if __GLIBC_PREREQ(2, 1)
683 #define HAVE_STRCHRNUL
684 #define HAVE_MEMPCPY
685 #endif
686 #endif
688 #ifndef HAVE_STRCHRNUL
689 #define strchrnul gitstrchrnul
690 static inline char *gitstrchrnul(const char *s, int c)
692 while (*s && *s != c)
693 s++;
694 return (char *)s;
696 #endif
698 #ifndef HAVE_MEMPCPY
699 #define mempcpy gitmempcpy
700 static inline void *gitmempcpy(void *dest, const void *src, size_t n)
702 return (char *)memcpy(dest, src, n) + n;
704 #endif
706 #ifdef NO_INET_PTON
707 int inet_pton(int af, const char *src, void *dst);
708 #endif
710 #ifdef NO_INET_NTOP
711 const char *inet_ntop(int af, const void *src, char *dst, size_t size);
712 #endif
714 #ifdef NO_PTHREADS
715 #define atexit git_atexit
716 extern int git_atexit(void (*handler)(void));
717 #endif
719 extern void release_pack_memory(size_t);
721 typedef void (*try_to_free_t)(size_t);
722 extern try_to_free_t set_try_to_free_routine(try_to_free_t);
724 static inline size_t st_add(size_t a, size_t b)
726 if (unsigned_add_overflows(a, b))
727 die("size_t overflow: %"PRIuMAX" + %"PRIuMAX,
728 (uintmax_t)a, (uintmax_t)b);
729 return a + b;
731 #define st_add3(a,b,c) st_add((a),st_add((b),(c)))
732 #define st_add4(a,b,c,d) st_add((a),st_add3((b),(c),(d)))
734 static inline size_t st_mult(size_t a, size_t b)
736 if (unsigned_mult_overflows(a, b))
737 die("size_t overflow: %"PRIuMAX" * %"PRIuMAX,
738 (uintmax_t)a, (uintmax_t)b);
739 return a * b;
742 static inline size_t st_sub(size_t a, size_t b)
744 if (a < b)
745 die("size_t underflow: %"PRIuMAX" - %"PRIuMAX,
746 (uintmax_t)a, (uintmax_t)b);
747 return a - b;
750 #ifdef HAVE_ALLOCA_H
751 # include <alloca.h>
752 # define xalloca(size) (alloca(size))
753 # define xalloca_free(p) do {} while (0)
754 #else
755 # define xalloca(size) (xmalloc(size))
756 # define xalloca_free(p) (free(p))
757 #endif
758 extern char *xstrdup(const char *str);
759 extern void *xmalloc(size_t size);
760 extern void *xmallocz(size_t size);
761 extern void *xmallocz_gently(size_t size);
762 extern void *xmemdupz(const void *data, size_t len);
763 extern char *xstrndup(const char *str, size_t len);
764 extern void *xrealloc(void *ptr, size_t size);
765 extern void *xcalloc(size_t nmemb, size_t size);
766 extern void *xmmap(void *start, size_t length, int prot, int flags, int fd, off_t offset);
767 extern void *xmmap_gently(void *start, size_t length, int prot, int flags, int fd, off_t offset);
768 extern int xopen(const char *path, int flags, ...);
769 extern ssize_t xread(int fd, void *buf, size_t len);
770 extern ssize_t xwrite(int fd, const void *buf, size_t len);
771 extern ssize_t xpread(int fd, void *buf, size_t len, off_t offset);
772 extern int xdup(int fd);
773 extern FILE *xfopen(const char *path, const char *mode);
774 extern FILE *xfdopen(int fd, const char *mode);
775 extern int xmkstemp(char *template);
776 extern int xmkstemp_mode(char *template, int mode);
777 extern int odb_mkstemp(char *template, size_t limit, const char *pattern);
778 extern int odb_pack_keep(char *name, size_t namesz, const unsigned char *sha1);
779 extern char *xgetcwd(void);
780 extern FILE *fopen_for_writing(const char *path);
782 #define ALLOC_ARRAY(x, alloc) (x) = xmalloc(st_mult(sizeof(*(x)), (alloc)))
783 #define REALLOC_ARRAY(x, alloc) (x) = xrealloc((x), st_mult(sizeof(*(x)), (alloc)))
786 * These functions help you allocate structs with flex arrays, and copy
787 * the data directly into the array. For example, if you had:
789 * struct foo {
790 * int bar;
791 * char name[FLEX_ARRAY];
792 * };
794 * you can do:
796 * struct foo *f;
797 * FLEX_ALLOC_MEM(f, name, src, len);
799 * to allocate a "foo" with the contents of "src" in the "name" field.
800 * The resulting struct is automatically zero'd, and the flex-array field
801 * is NUL-terminated (whether the incoming src buffer was or not).
803 * The FLEXPTR_* variants operate on structs that don't use flex-arrays,
804 * but do want to store a pointer to some extra data in the same allocated
805 * block. For example, if you have:
807 * struct foo {
808 * char *name;
809 * int bar;
810 * };
812 * you can do:
814 * struct foo *f;
815 * FLEX_ALLOC_STR(f, name, src);
817 * and "name" will point to a block of memory after the struct, which will be
818 * freed along with the struct (but the pointer can be repointed anywhere).
820 * The *_STR variants accept a string parameter rather than a ptr/len
821 * combination.
823 * Note that these macros will evaluate the first parameter multiple
824 * times, and it must be assignable as an lvalue.
826 #define FLEX_ALLOC_MEM(x, flexname, buf, len) do { \
827 (x) = NULL; /* silence -Wuninitialized for offset calculation */ \
828 (x) = xalloc_flex(sizeof(*(x)), (char *)(&((x)->flexname)) - (char *)(x), (buf), (len)); \
829 } while (0)
830 #define FLEXPTR_ALLOC_MEM(x, ptrname, buf, len) do { \
831 (x) = xalloc_flex(sizeof(*(x)), sizeof(*(x)), (buf), (len)); \
832 (x)->ptrname = (void *)((x)+1); \
833 } while(0)
834 #define FLEX_ALLOC_STR(x, flexname, str) \
835 FLEX_ALLOC_MEM((x), flexname, (str), strlen(str))
836 #define FLEXPTR_ALLOC_STR(x, ptrname, str) \
837 FLEXPTR_ALLOC_MEM((x), ptrname, (str), strlen(str))
839 static inline void *xalloc_flex(size_t base_len, size_t offset,
840 const void *src, size_t src_len)
842 unsigned char *ret = xcalloc(1, st_add3(base_len, src_len, 1));
843 memcpy(ret + offset, src, src_len);
844 return ret;
847 static inline char *xstrdup_or_null(const char *str)
849 return str ? xstrdup(str) : NULL;
852 static inline size_t xsize_t(off_t len)
854 if (len > (size_t) len)
855 die("Cannot handle files this big");
856 return (size_t)len;
859 __attribute__((format (printf, 3, 4)))
860 extern int xsnprintf(char *dst, size_t max, const char *fmt, ...);
862 /* in ctype.c, for kwset users */
863 extern const unsigned char tolower_trans_tbl[256];
865 /* Sane ctype - no locale, and works with signed chars */
866 #undef isascii
867 #undef isspace
868 #undef isdigit
869 #undef isalpha
870 #undef isalnum
871 #undef isprint
872 #undef islower
873 #undef isupper
874 #undef tolower
875 #undef toupper
876 #undef iscntrl
877 #undef ispunct
878 #undef isxdigit
880 extern const unsigned char sane_ctype[256];
881 #define GIT_SPACE 0x01
882 #define GIT_DIGIT 0x02
883 #define GIT_ALPHA 0x04
884 #define GIT_GLOB_SPECIAL 0x08
885 #define GIT_REGEX_SPECIAL 0x10
886 #define GIT_PATHSPEC_MAGIC 0x20
887 #define GIT_CNTRL 0x40
888 #define GIT_PUNCT 0x80
889 #define sane_istest(x,mask) ((sane_ctype[(unsigned char)(x)] & (mask)) != 0)
890 #define isascii(x) (((x) & ~0x7f) == 0)
891 #define isspace(x) sane_istest(x,GIT_SPACE)
892 #define isdigit(x) sane_istest(x,GIT_DIGIT)
893 #define isalpha(x) sane_istest(x,GIT_ALPHA)
894 #define isalnum(x) sane_istest(x,GIT_ALPHA | GIT_DIGIT)
895 #define isprint(x) ((x) >= 0x20 && (x) <= 0x7e)
896 #define islower(x) sane_iscase(x, 1)
897 #define isupper(x) sane_iscase(x, 0)
898 #define is_glob_special(x) sane_istest(x,GIT_GLOB_SPECIAL)
899 #define is_regex_special(x) sane_istest(x,GIT_GLOB_SPECIAL | GIT_REGEX_SPECIAL)
900 #define iscntrl(x) (sane_istest(x,GIT_CNTRL))
901 #define ispunct(x) sane_istest(x, GIT_PUNCT | GIT_REGEX_SPECIAL | \
902 GIT_GLOB_SPECIAL | GIT_PATHSPEC_MAGIC)
903 #define isxdigit(x) (hexval_table[(unsigned char)(x)] != -1)
904 #define tolower(x) sane_case((unsigned char)(x), 0x20)
905 #define toupper(x) sane_case((unsigned char)(x), 0)
906 #define is_pathspec_magic(x) sane_istest(x,GIT_PATHSPEC_MAGIC)
908 static inline int sane_case(int x, int high)
910 if (sane_istest(x, GIT_ALPHA))
911 x = (x & ~0x20) | high;
912 return x;
915 static inline int sane_iscase(int x, int is_lower)
917 if (!sane_istest(x, GIT_ALPHA))
918 return 0;
920 if (is_lower)
921 return (x & 0x20) != 0;
922 else
923 return (x & 0x20) == 0;
926 static inline int strtoul_ui(char const *s, int base, unsigned int *result)
928 unsigned long ul;
929 char *p;
931 errno = 0;
932 /* negative values would be accepted by strtoul */
933 if (strchr(s, '-'))
934 return -1;
935 ul = strtoul(s, &p, base);
936 if (errno || *p || p == s || (unsigned int) ul != ul)
937 return -1;
938 *result = ul;
939 return 0;
942 static inline int strtol_i(char const *s, int base, int *result)
944 long ul;
945 char *p;
947 errno = 0;
948 ul = strtol(s, &p, base);
949 if (errno || *p || p == s || (int) ul != ul)
950 return -1;
951 *result = ul;
952 return 0;
955 #ifdef INTERNAL_QSORT
956 void git_qsort(void *base, size_t nmemb, size_t size,
957 int(*compar)(const void *, const void *));
958 #define qsort git_qsort
959 #endif
961 #ifndef DIR_HAS_BSD_GROUP_SEMANTICS
962 # define FORCE_DIR_SET_GID S_ISGID
963 #else
964 # define FORCE_DIR_SET_GID 0
965 #endif
967 #ifdef NO_NSEC
968 #undef USE_NSEC
969 #define ST_CTIME_NSEC(st) 0
970 #define ST_MTIME_NSEC(st) 0
971 #else
972 #ifdef USE_ST_TIMESPEC
973 #define ST_CTIME_NSEC(st) ((unsigned int)((st).st_ctimespec.tv_nsec))
974 #define ST_MTIME_NSEC(st) ((unsigned int)((st).st_mtimespec.tv_nsec))
975 #else
976 #define ST_CTIME_NSEC(st) ((unsigned int)((st).st_ctim.tv_nsec))
977 #define ST_MTIME_NSEC(st) ((unsigned int)((st).st_mtim.tv_nsec))
978 #endif
979 #endif
981 #ifdef UNRELIABLE_FSTAT
982 #define fstat_is_reliable() 0
983 #else
984 #define fstat_is_reliable() 1
985 #endif
987 #ifndef va_copy
989 * Since an obvious implementation of va_list would be to make it a
990 * pointer into the stack frame, a simple assignment will work on
991 * many systems. But let's try to be more portable.
993 #ifdef __va_copy
994 #define va_copy(dst, src) __va_copy(dst, src)
995 #else
996 #define va_copy(dst, src) ((dst) = (src))
997 #endif
998 #endif
1000 #if defined(__GNUC__) || (_MSC_VER >= 1400) || defined(__C99_MACRO_WITH_VA_ARGS)
1001 #define HAVE_VARIADIC_MACROS 1
1002 #endif
1005 * Preserves errno, prints a message, but gives no warning for ENOENT.
1006 * Returns 0 on success, which includes trying to unlink an object that does
1007 * not exist.
1009 int unlink_or_warn(const char *path);
1011 * Tries to unlink file. Returns 0 if unlink succeeded
1012 * or the file already didn't exist. Returns -1 and
1013 * appends a message to err suitable for
1014 * 'error("%s", err->buf)' on error.
1016 int unlink_or_msg(const char *file, struct strbuf *err);
1018 * Preserves errno, prints a message, but gives no warning for ENOENT.
1019 * Returns 0 on success, which includes trying to remove a directory that does
1020 * not exist.
1022 int rmdir_or_warn(const char *path);
1024 * Calls the correct function out of {unlink,rmdir}_or_warn based on
1025 * the supplied file mode.
1027 int remove_or_warn(unsigned int mode, const char *path);
1030 * Call access(2), but warn for any error except "missing file"
1031 * (ENOENT or ENOTDIR).
1033 #define ACCESS_EACCES_OK (1U << 0)
1034 int access_or_warn(const char *path, int mode, unsigned flag);
1035 int access_or_die(const char *path, int mode, unsigned flag);
1037 /* Warn on an inaccessible file that ought to be accessible */
1038 void warn_on_inaccessible(const char *path);
1040 #ifdef GMTIME_UNRELIABLE_ERRORS
1041 struct tm *git_gmtime(const time_t *);
1042 struct tm *git_gmtime_r(const time_t *, struct tm *);
1043 #define gmtime git_gmtime
1044 #define gmtime_r git_gmtime_r
1045 #endif
1047 #if !defined(USE_PARENS_AROUND_GETTEXT_N) && defined(__GNUC__)
1048 #define USE_PARENS_AROUND_GETTEXT_N 1
1049 #endif
1051 #ifndef SHELL_PATH
1052 # define SHELL_PATH "/bin/sh"
1053 #endif
1055 #ifndef _POSIX_THREAD_SAFE_FUNCTIONS
1056 #define flockfile(fh)
1057 #define funlockfile(fh)
1058 #define getc_unlocked(fh) getc(fh)
1059 #endif
1061 #endif