Documentation: clarify signature verification
[git/git-svn.git] / git-compat-util.h
blob474395471f623d6a02de9814a5490f3b1df3a0f1
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 has_dos_drive_prefix
337 static inline int git_has_dos_drive_prefix(const char *path)
339 return 0;
341 #define has_dos_drive_prefix git_has_dos_drive_prefix
342 #endif
344 #ifndef skip_dos_drive_prefix
345 static inline int git_skip_dos_drive_prefix(char **path)
347 return 0;
349 #define skip_dos_drive_prefix git_skip_dos_drive_prefix
350 #endif
352 #ifndef is_dir_sep
353 static inline int git_is_dir_sep(int c)
355 return c == '/';
357 #define is_dir_sep git_is_dir_sep
358 #endif
360 #ifndef offset_1st_component
361 static inline int git_offset_1st_component(const char *path)
363 return is_dir_sep(path[0]);
365 #define offset_1st_component git_offset_1st_component
366 #endif
368 #ifndef find_last_dir_sep
369 static inline char *git_find_last_dir_sep(const char *path)
371 return strrchr(path, '/');
373 #define find_last_dir_sep git_find_last_dir_sep
374 #endif
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
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
402 #include "compat/bswap.h"
404 #include "wildmatch.h"
406 struct strbuf;
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 void warning(const char *err, ...) __attribute__((format (printf, 1, 2)));
417 #ifndef NO_OPENSSL
418 #ifdef APPLE_COMMON_CRYPTO
419 #include "compat/apple-common-crypto.h"
420 #else
421 #include <openssl/evp.h>
422 #include <openssl/hmac.h>
423 #endif /* APPLE_COMMON_CRYPTO */
424 #include <openssl/x509v3.h>
425 #endif /* NO_OPENSSL */
428 * Let callers be aware of the constant return value; this can help
429 * gcc with -Wuninitialized analysis. We restrict this trick to gcc, though,
430 * because some compilers may not support variadic macros. Since we're only
431 * trying to help gcc, anyway, it's OK; other compilers will fall back to
432 * using the function as usual.
434 #if defined(__GNUC__)
435 static inline int const_error(void)
437 return -1;
439 #define error(...) (error(__VA_ARGS__), const_error())
440 #endif
442 extern void set_die_routine(NORETURN_PTR void (*routine)(const char *err, va_list params));
443 extern void set_error_routine(void (*routine)(const char *err, va_list params));
444 extern void set_die_is_recursing_routine(int (*routine)(void));
445 extern void set_error_handle(FILE *);
447 extern int starts_with(const char *str, const char *prefix);
450 * If the string "str" begins with the string found in "prefix", return 1.
451 * The "out" parameter is set to "str + strlen(prefix)" (i.e., to the point in
452 * the string right after the prefix).
454 * Otherwise, return 0 and leave "out" untouched.
456 * Examples:
458 * [extract branch name, fail if not a branch]
459 * if (!skip_prefix(ref, "refs/heads/", &branch)
460 * return -1;
462 * [skip prefix if present, otherwise use whole string]
463 * skip_prefix(name, "refs/heads/", &name);
465 static inline int skip_prefix(const char *str, const char *prefix,
466 const char **out)
468 do {
469 if (!*prefix) {
470 *out = str;
471 return 1;
473 } while (*str++ == *prefix++);
474 return 0;
478 * If buf ends with suffix, return 1 and subtract the length of the suffix
479 * from *len. Otherwise, return 0 and leave *len untouched.
481 static inline int strip_suffix_mem(const char *buf, size_t *len,
482 const char *suffix)
484 size_t suflen = strlen(suffix);
485 if (*len < suflen || memcmp(buf + (*len - suflen), suffix, suflen))
486 return 0;
487 *len -= suflen;
488 return 1;
492 * If str ends with suffix, return 1 and set *len to the size of the string
493 * without the suffix. Otherwise, return 0 and set *len to the size of the
494 * string.
496 * Note that we do _not_ NUL-terminate str to the new length.
498 static inline int strip_suffix(const char *str, const char *suffix, size_t *len)
500 *len = strlen(str);
501 return strip_suffix_mem(str, len, suffix);
504 static inline int ends_with(const char *str, const char *suffix)
506 size_t len;
507 return strip_suffix(str, suffix, &len);
510 #if defined(NO_MMAP) || defined(USE_WIN32_MMAP)
512 #ifndef PROT_READ
513 #define PROT_READ 1
514 #define PROT_WRITE 2
515 #define MAP_PRIVATE 1
516 #endif
518 #define mmap git_mmap
519 #define munmap git_munmap
520 extern void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset);
521 extern int git_munmap(void *start, size_t length);
523 #else /* NO_MMAP || USE_WIN32_MMAP */
525 #include <sys/mman.h>
527 #endif /* NO_MMAP || USE_WIN32_MMAP */
529 #ifdef NO_MMAP
531 /* This value must be multiple of (pagesize * 2) */
532 #define DEFAULT_PACKED_GIT_WINDOW_SIZE (1 * 1024 * 1024)
534 #else /* NO_MMAP */
536 /* This value must be multiple of (pagesize * 2) */
537 #define DEFAULT_PACKED_GIT_WINDOW_SIZE \
538 (sizeof(void*) >= 8 \
539 ? 1 * 1024 * 1024 * 1024 \
540 : 32 * 1024 * 1024)
542 #endif /* NO_MMAP */
544 #ifndef MAP_FAILED
545 #define MAP_FAILED ((void *)-1)
546 #endif
548 #ifdef NO_ST_BLOCKS_IN_STRUCT_STAT
549 #define on_disk_bytes(st) ((st).st_size)
550 #else
551 #define on_disk_bytes(st) ((st).st_blocks * 512)
552 #endif
554 #ifdef NEEDS_MODE_TRANSLATION
555 #undef S_IFMT
556 #undef S_IFREG
557 #undef S_IFDIR
558 #undef S_IFLNK
559 #undef S_IFBLK
560 #undef S_IFCHR
561 #undef S_IFIFO
562 #undef S_IFSOCK
563 #define S_IFMT 0170000
564 #define S_IFREG 0100000
565 #define S_IFDIR 0040000
566 #define S_IFLNK 0120000
567 #define S_IFBLK 0060000
568 #define S_IFCHR 0020000
569 #define S_IFIFO 0010000
570 #define S_IFSOCK 0140000
571 #ifdef stat
572 #undef stat
573 #endif
574 #define stat(path, buf) git_stat(path, buf)
575 extern int git_stat(const char *, struct stat *);
576 #ifdef fstat
577 #undef fstat
578 #endif
579 #define fstat(fd, buf) git_fstat(fd, buf)
580 extern int git_fstat(int, struct stat *);
581 #ifdef lstat
582 #undef lstat
583 #endif
584 #define lstat(path, buf) git_lstat(path, buf)
585 extern int git_lstat(const char *, struct stat *);
586 #endif
588 #define DEFAULT_PACKED_GIT_LIMIT \
589 ((1024L * 1024L) * (size_t)(sizeof(void*) >= 8 ? 8192 : 256))
591 #ifdef NO_PREAD
592 #define pread git_pread
593 extern ssize_t git_pread(int fd, void *buf, size_t count, off_t offset);
594 #endif
596 * Forward decl that will remind us if its twin in cache.h changes.
597 * This function is used in compat/pread.c. But we can't include
598 * cache.h there.
600 extern ssize_t read_in_full(int fd, void *buf, size_t count);
602 #ifdef NO_SETENV
603 #define setenv gitsetenv
604 extern int gitsetenv(const char *, const char *, int);
605 #endif
607 #ifdef NO_MKDTEMP
608 #define mkdtemp gitmkdtemp
609 extern char *gitmkdtemp(char *);
610 #endif
612 #ifdef NO_MKSTEMPS
613 #define mkstemps gitmkstemps
614 extern int gitmkstemps(char *, int);
615 #endif
617 #ifdef NO_UNSETENV
618 #define unsetenv gitunsetenv
619 extern void gitunsetenv(const char *);
620 #endif
622 #ifdef NO_STRCASESTR
623 #define strcasestr gitstrcasestr
624 extern char *gitstrcasestr(const char *haystack, const char *needle);
625 #endif
627 #ifdef NO_STRLCPY
628 #define strlcpy gitstrlcpy
629 extern size_t gitstrlcpy(char *, const char *, size_t);
630 #endif
632 #ifdef NO_STRTOUMAX
633 #define strtoumax gitstrtoumax
634 extern uintmax_t gitstrtoumax(const char *, char **, int);
635 #define strtoimax gitstrtoimax
636 extern intmax_t gitstrtoimax(const char *, char **, int);
637 #endif
639 #ifdef NO_HSTRERROR
640 #define hstrerror githstrerror
641 extern const char *githstrerror(int herror);
642 #endif
644 #ifdef NO_MEMMEM
645 #define memmem gitmemmem
646 void *gitmemmem(const void *haystack, size_t haystacklen,
647 const void *needle, size_t needlelen);
648 #endif
650 #ifdef NO_GETPAGESIZE
651 #define getpagesize() sysconf(_SC_PAGESIZE)
652 #endif
654 #ifdef FREAD_READS_DIRECTORIES
655 #ifdef fopen
656 #undef fopen
657 #endif
658 #define fopen(a,b) git_fopen(a,b)
659 extern FILE *git_fopen(const char*, const char*);
660 #endif
662 #ifdef SNPRINTF_RETURNS_BOGUS
663 #ifdef snprintf
664 #undef snprintf
665 #endif
666 #define snprintf git_snprintf
667 extern int git_snprintf(char *str, size_t maxsize,
668 const char *format, ...);
669 #ifdef vsnprintf
670 #undef vsnprintf
671 #endif
672 #define vsnprintf git_vsnprintf
673 extern int git_vsnprintf(char *str, size_t maxsize,
674 const char *format, va_list ap);
675 #endif
677 #ifdef __GLIBC_PREREQ
678 #if __GLIBC_PREREQ(2, 1)
679 #define HAVE_STRCHRNUL
680 #endif
681 #endif
683 #ifndef HAVE_STRCHRNUL
684 #define strchrnul gitstrchrnul
685 static inline char *gitstrchrnul(const char *s, int c)
687 while (*s && *s != c)
688 s++;
689 return (char *)s;
691 #endif
693 #ifdef NO_INET_PTON
694 int inet_pton(int af, const char *src, void *dst);
695 #endif
697 #ifdef NO_INET_NTOP
698 const char *inet_ntop(int af, const void *src, char *dst, size_t size);
699 #endif
701 #ifdef NO_PTHREADS
702 #define atexit git_atexit
703 extern int git_atexit(void (*handler)(void));
704 #endif
706 extern void release_pack_memory(size_t);
708 typedef void (*try_to_free_t)(size_t);
709 extern try_to_free_t set_try_to_free_routine(try_to_free_t);
711 static inline size_t st_add(size_t a, size_t b)
713 if (unsigned_add_overflows(a, b))
714 die("size_t overflow: %"PRIuMAX" + %"PRIuMAX,
715 (uintmax_t)a, (uintmax_t)b);
716 return a + b;
718 #define st_add3(a,b,c) st_add(st_add((a),(b)),(c))
719 #define st_add4(a,b,c,d) st_add(st_add3((a),(b),(c)),(d))
721 static inline size_t st_mult(size_t a, size_t b)
723 if (unsigned_mult_overflows(a, b))
724 die("size_t overflow: %"PRIuMAX" * %"PRIuMAX,
725 (uintmax_t)a, (uintmax_t)b);
726 return a * b;
729 static inline size_t st_sub(size_t a, size_t b)
731 if (a < b)
732 die("size_t underflow: %"PRIuMAX" - %"PRIuMAX,
733 (uintmax_t)a, (uintmax_t)b);
734 return a - b;
737 #ifdef HAVE_ALLOCA_H
738 # include <alloca.h>
739 # define xalloca(size) (alloca(size))
740 # define xalloca_free(p) do {} while (0)
741 #else
742 # define xalloca(size) (xmalloc(size))
743 # define xalloca_free(p) (free(p))
744 #endif
745 extern char *xstrdup(const char *str);
746 extern void *xmalloc(size_t size);
747 extern void *xmallocz(size_t size);
748 extern void *xmallocz_gently(size_t size);
749 extern void *xmemdupz(const void *data, size_t len);
750 extern char *xstrndup(const char *str, size_t len);
751 extern void *xrealloc(void *ptr, size_t size);
752 extern void *xcalloc(size_t nmemb, size_t size);
753 extern void *xmmap(void *start, size_t length, int prot, int flags, int fd, off_t offset);
754 extern void *xmmap_gently(void *start, size_t length, int prot, int flags, int fd, off_t offset);
755 extern int xopen(const char *path, int flags, ...);
756 extern ssize_t xread(int fd, void *buf, size_t len);
757 extern ssize_t xwrite(int fd, const void *buf, size_t len);
758 extern ssize_t xpread(int fd, void *buf, size_t len, off_t offset);
759 extern int xdup(int fd);
760 extern FILE *xfopen(const char *path, const char *mode);
761 extern FILE *xfdopen(int fd, const char *mode);
762 extern int xmkstemp(char *template);
763 extern int xmkstemp_mode(char *template, int mode);
764 extern int odb_mkstemp(char *template, size_t limit, const char *pattern);
765 extern int odb_pack_keep(char *name, size_t namesz, const unsigned char *sha1);
766 extern char *xgetcwd(void);
767 extern FILE *fopen_for_writing(const char *path);
769 #define ALLOC_ARRAY(x, alloc) (x) = xmalloc(st_mult(sizeof(*(x)), (alloc)))
770 #define REALLOC_ARRAY(x, alloc) (x) = xrealloc((x), st_mult(sizeof(*(x)), (alloc)))
773 * These functions help you allocate structs with flex arrays, and copy
774 * the data directly into the array. For example, if you had:
776 * struct foo {
777 * int bar;
778 * char name[FLEX_ARRAY];
779 * };
781 * you can do:
783 * struct foo *f;
784 * FLEX_ALLOC_MEM(f, name, src, len);
786 * to allocate a "foo" with the contents of "src" in the "name" field.
787 * The resulting struct is automatically zero'd, and the flex-array field
788 * is NUL-terminated (whether the incoming src buffer was or not).
790 * The FLEXPTR_* variants operate on structs that don't use flex-arrays,
791 * but do want to store a pointer to some extra data in the same allocated
792 * block. For example, if you have:
794 * struct foo {
795 * char *name;
796 * int bar;
797 * };
799 * you can do:
801 * struct foo *f;
802 * FLEX_ALLOC_STR(f, name, src);
804 * and "name" will point to a block of memory after the struct, which will be
805 * freed along with the struct (but the pointer can be repointed anywhere).
807 * The *_STR variants accept a string parameter rather than a ptr/len
808 * combination.
810 * Note that these macros will evaluate the first parameter multiple
811 * times, and it must be assignable as an lvalue.
813 #define FLEX_ALLOC_MEM(x, flexname, buf, len) do { \
814 (x) = NULL; /* silence -Wuninitialized for offset calculation */ \
815 (x) = xalloc_flex(sizeof(*(x)), (char *)(&((x)->flexname)) - (char *)(x), (buf), (len)); \
816 } while (0)
817 #define FLEXPTR_ALLOC_MEM(x, ptrname, buf, len) do { \
818 (x) = xalloc_flex(sizeof(*(x)), sizeof(*(x)), (buf), (len)); \
819 (x)->ptrname = (void *)((x)+1); \
820 } while(0)
821 #define FLEX_ALLOC_STR(x, flexname, str) \
822 FLEX_ALLOC_MEM((x), flexname, (str), strlen(str))
823 #define FLEXPTR_ALLOC_STR(x, ptrname, str) \
824 FLEXPTR_ALLOC_MEM((x), ptrname, (str), strlen(str))
826 static inline void *xalloc_flex(size_t base_len, size_t offset,
827 const void *src, size_t src_len)
829 unsigned char *ret = xcalloc(1, st_add3(base_len, src_len, 1));
830 memcpy(ret + offset, src, src_len);
831 return ret;
834 static inline char *xstrdup_or_null(const char *str)
836 return str ? xstrdup(str) : NULL;
839 static inline size_t xsize_t(off_t len)
841 if (len > (size_t) len)
842 die("Cannot handle files this big");
843 return (size_t)len;
846 __attribute__((format (printf, 3, 4)))
847 extern int xsnprintf(char *dst, size_t max, const char *fmt, ...);
849 /* in ctype.c, for kwset users */
850 extern const unsigned char tolower_trans_tbl[256];
852 /* Sane ctype - no locale, and works with signed chars */
853 #undef isascii
854 #undef isspace
855 #undef isdigit
856 #undef isalpha
857 #undef isalnum
858 #undef isprint
859 #undef islower
860 #undef isupper
861 #undef tolower
862 #undef toupper
863 #undef iscntrl
864 #undef ispunct
865 #undef isxdigit
867 extern const unsigned char sane_ctype[256];
868 #define GIT_SPACE 0x01
869 #define GIT_DIGIT 0x02
870 #define GIT_ALPHA 0x04
871 #define GIT_GLOB_SPECIAL 0x08
872 #define GIT_REGEX_SPECIAL 0x10
873 #define GIT_PATHSPEC_MAGIC 0x20
874 #define GIT_CNTRL 0x40
875 #define GIT_PUNCT 0x80
876 #define sane_istest(x,mask) ((sane_ctype[(unsigned char)(x)] & (mask)) != 0)
877 #define isascii(x) (((x) & ~0x7f) == 0)
878 #define isspace(x) sane_istest(x,GIT_SPACE)
879 #define isdigit(x) sane_istest(x,GIT_DIGIT)
880 #define isalpha(x) sane_istest(x,GIT_ALPHA)
881 #define isalnum(x) sane_istest(x,GIT_ALPHA | GIT_DIGIT)
882 #define isprint(x) ((x) >= 0x20 && (x) <= 0x7e)
883 #define islower(x) sane_iscase(x, 1)
884 #define isupper(x) sane_iscase(x, 0)
885 #define is_glob_special(x) sane_istest(x,GIT_GLOB_SPECIAL)
886 #define is_regex_special(x) sane_istest(x,GIT_GLOB_SPECIAL | GIT_REGEX_SPECIAL)
887 #define iscntrl(x) (sane_istest(x,GIT_CNTRL))
888 #define ispunct(x) sane_istest(x, GIT_PUNCT | GIT_REGEX_SPECIAL | \
889 GIT_GLOB_SPECIAL | GIT_PATHSPEC_MAGIC)
890 #define isxdigit(x) (hexval_table[(unsigned char)(x)] != -1)
891 #define tolower(x) sane_case((unsigned char)(x), 0x20)
892 #define toupper(x) sane_case((unsigned char)(x), 0)
893 #define is_pathspec_magic(x) sane_istest(x,GIT_PATHSPEC_MAGIC)
895 static inline int sane_case(int x, int high)
897 if (sane_istest(x, GIT_ALPHA))
898 x = (x & ~0x20) | high;
899 return x;
902 static inline int sane_iscase(int x, int is_lower)
904 if (!sane_istest(x, GIT_ALPHA))
905 return 0;
907 if (is_lower)
908 return (x & 0x20) != 0;
909 else
910 return (x & 0x20) == 0;
913 static inline int strtoul_ui(char const *s, int base, unsigned int *result)
915 unsigned long ul;
916 char *p;
918 errno = 0;
919 /* negative values would be accepted by strtoul */
920 if (strchr(s, '-'))
921 return -1;
922 ul = strtoul(s, &p, base);
923 if (errno || *p || p == s || (unsigned int) ul != ul)
924 return -1;
925 *result = ul;
926 return 0;
929 static inline int strtol_i(char const *s, int base, int *result)
931 long ul;
932 char *p;
934 errno = 0;
935 ul = strtol(s, &p, base);
936 if (errno || *p || p == s || (int) ul != ul)
937 return -1;
938 *result = ul;
939 return 0;
942 #ifdef INTERNAL_QSORT
943 void git_qsort(void *base, size_t nmemb, size_t size,
944 int(*compar)(const void *, const void *));
945 #define qsort git_qsort
946 #endif
948 #ifndef DIR_HAS_BSD_GROUP_SEMANTICS
949 # define FORCE_DIR_SET_GID S_ISGID
950 #else
951 # define FORCE_DIR_SET_GID 0
952 #endif
954 #ifdef NO_NSEC
955 #undef USE_NSEC
956 #define ST_CTIME_NSEC(st) 0
957 #define ST_MTIME_NSEC(st) 0
958 #else
959 #ifdef USE_ST_TIMESPEC
960 #define ST_CTIME_NSEC(st) ((unsigned int)((st).st_ctimespec.tv_nsec))
961 #define ST_MTIME_NSEC(st) ((unsigned int)((st).st_mtimespec.tv_nsec))
962 #else
963 #define ST_CTIME_NSEC(st) ((unsigned int)((st).st_ctim.tv_nsec))
964 #define ST_MTIME_NSEC(st) ((unsigned int)((st).st_mtim.tv_nsec))
965 #endif
966 #endif
968 #ifdef UNRELIABLE_FSTAT
969 #define fstat_is_reliable() 0
970 #else
971 #define fstat_is_reliable() 1
972 #endif
974 #ifndef va_copy
976 * Since an obvious implementation of va_list would be to make it a
977 * pointer into the stack frame, a simple assignment will work on
978 * many systems. But let's try to be more portable.
980 #ifdef __va_copy
981 #define va_copy(dst, src) __va_copy(dst, src)
982 #else
983 #define va_copy(dst, src) ((dst) = (src))
984 #endif
985 #endif
987 #if defined(__GNUC__) || (_MSC_VER >= 1400) || defined(__C99_MACRO_WITH_VA_ARGS)
988 #define HAVE_VARIADIC_MACROS 1
989 #endif
992 * Preserves errno, prints a message, but gives no warning for ENOENT.
993 * Returns 0 on success, which includes trying to unlink an object that does
994 * not exist.
996 int unlink_or_warn(const char *path);
998 * Tries to unlink file. Returns 0 if unlink succeeded
999 * or the file already didn't exist. Returns -1 and
1000 * appends a message to err suitable for
1001 * 'error("%s", err->buf)' on error.
1003 int unlink_or_msg(const char *file, struct strbuf *err);
1005 * Preserves errno, prints a message, but gives no warning for ENOENT.
1006 * Returns 0 on success, which includes trying to remove a directory that does
1007 * not exist.
1009 int rmdir_or_warn(const char *path);
1011 * Calls the correct function out of {unlink,rmdir}_or_warn based on
1012 * the supplied file mode.
1014 int remove_or_warn(unsigned int mode, const char *path);
1017 * Call access(2), but warn for any error except "missing file"
1018 * (ENOENT or ENOTDIR).
1020 #define ACCESS_EACCES_OK (1U << 0)
1021 int access_or_warn(const char *path, int mode, unsigned flag);
1022 int access_or_die(const char *path, int mode, unsigned flag);
1024 /* Warn on an inaccessible file that ought to be accessible */
1025 void warn_on_inaccessible(const char *path);
1027 #ifdef GMTIME_UNRELIABLE_ERRORS
1028 struct tm *git_gmtime(const time_t *);
1029 struct tm *git_gmtime_r(const time_t *, struct tm *);
1030 #define gmtime git_gmtime
1031 #define gmtime_r git_gmtime_r
1032 #endif
1034 #if !defined(USE_PARENS_AROUND_GETTEXT_N) && defined(__GNUC__)
1035 #define USE_PARENS_AROUND_GETTEXT_N 1
1036 #endif
1038 #ifndef SHELL_PATH
1039 # define SHELL_PATH "/bin/sh"
1040 #endif
1042 #ifndef _POSIX_THREAD_SAFE_FUNCTIONS
1043 #define flockfile(fh)
1044 #define funlockfile(fh)
1045 #define getc_unlocked(fh) getc(fh)
1046 #endif
1048 #endif