Bug Summary

File:wrapper.c
Location:line 505, column 43
Description:Value stored to 'v' is never read

Annotated Source Code

1/*
2 * Various trivial helper wrappers around standard functions
3 */
4#include "cache.h"
5
6static void do_nothing(size_t size)
7{
8}
9
10static void (*try_to_free_routine)(size_t size) = do_nothing;
11
12static int memory_limit_check(size_t size, int gentle)
13{
14 static size_t limit = 0;
15 if (!limit) {
16 limit = git_env_ulong("GIT_ALLOC_LIMIT", 0);
17 if (!limit)
18 limit = SIZE_MAX18446744073709551615ULL;
19 }
20 if (size > limit) {
21 if (gentle) {
22 error("attempting to allocate %"PRIuMAX" over limit %"PRIuMAX,(error("attempting to allocate %""j" "u"" over limit %""j" "u"
, (uintmax_t)size, (uintmax_t)limit), const_error())
23 (uintmax_t)size, (uintmax_t)limit)(error("attempting to allocate %""j" "u"" over limit %""j" "u"
, (uintmax_t)size, (uintmax_t)limit), const_error());
24 return -1;
25 } else
26 die("attempting to allocate %"PRIuMAX"j" "u"" over limit %"PRIuMAX"j" "u",
27 (uintmax_t)size, (uintmax_t)limit);
28 }
29 return 0;
30}
31
32try_to_free_t set_try_to_free_routine(try_to_free_t routine)
33{
34 try_to_free_t old = try_to_free_routine;
35 if (!routine)
36 routine = do_nothing;
37 try_to_free_routine = routine;
38 return old;
39}
40
41char *xstrdup(const char *str)
42{
43 char *ret = strdup(str);
44 if (!ret) {
45 try_to_free_routine(strlen(str) + 1);
46 ret = strdup(str);
47 if (!ret)
48 die("Out of memory, strdup failed");
49 }
50 return ret;
51}
52
53static void *do_xmalloc(size_t size, int gentle)
54{
55 void *ret;
56
57 if (memory_limit_check(size, gentle))
58 return NULL((void*)0);
59 ret = malloc(size);
60 if (!ret && !size)
61 ret = malloc(1);
62 if (!ret) {
63 try_to_free_routine(size);
64 ret = malloc(size);
65 if (!ret && !size)
66 ret = malloc(1);
67 if (!ret) {
68 if (!gentle)
69 die("Out of memory, malloc failed (tried to allocate %lu bytes)",
70 (unsigned long)size);
71 else {
72 error("Out of memory, malloc failed (tried to allocate %lu bytes)",(error("Out of memory, malloc failed (tried to allocate %lu bytes)"
, (unsigned long)size), const_error())
73 (unsigned long)size)(error("Out of memory, malloc failed (tried to allocate %lu bytes)"
, (unsigned long)size), const_error());
74 return NULL((void*)0);
75 }
76 }
77 }
78#ifdef XMALLOC_POISON
79 memset(ret, 0xA5, size)__builtin___memset_chk (ret, 0xA5, size, __builtin_object_size
(ret, 0));
80#endif
81 return ret;
82}
83
84void *xmalloc(size_t size)
85{
86 return do_xmalloc(size, 0);
87}
88
89static void *do_xmallocz(size_t size, int gentle)
90{
91 void *ret;
92 if (unsigned_add_overflows(size, 1)((1) > (18446744073709551615ULL >> ((8 * sizeof(uintmax_t
)) - (8 * sizeof(size)))) - (size))) {
93 if (gentle) {
94 error("Data too large to fit into virtual memory space.")(error("Data too large to fit into virtual memory space."), const_error
());
95 return NULL((void*)0);
96 } else
97 die("Data too large to fit into virtual memory space.");
98 }
99 ret = do_xmalloc(size + 1, gentle);
100 if (ret)
101 ((char*)ret)[size] = 0;
102 return ret;
103}
104
105void *xmallocz(size_t size)
106{
107 return do_xmallocz(size, 0);
108}
109
110void *xmallocz_gently(size_t size)
111{
112 return do_xmallocz(size, 1);
113}
114
115/*
116 * xmemdupz() allocates (len + 1) bytes of memory, duplicates "len" bytes of
117 * "data" to the allocated memory, zero terminates the allocated memory,
118 * and returns a pointer to the allocated memory. If the allocation fails,
119 * the program dies.
120 */
121void *xmemdupz(const void *data, size_t len)
122{
123 return memcpy(xmallocz(len), data, len)__builtin___memcpy_chk (xmallocz(len), data, len, __builtin_object_size
(xmallocz(len), 0));
124}
125
126char *xstrndup(const char *str, size_t len)
127{
128 char *p = memchr(str, '\0', len);
129 return xmemdupz(str, p ? p - str : len);
130}
131
132void *xrealloc(void *ptr, size_t size)
133{
134 void *ret;
135
136 memory_limit_check(size, 0);
137 ret = realloc(ptr, size);
138 if (!ret && !size)
139 ret = realloc(ptr, 1);
140 if (!ret) {
141 try_to_free_routine(size);
142 ret = realloc(ptr, size);
143 if (!ret && !size)
144 ret = realloc(ptr, 1);
145 if (!ret)
146 die("Out of memory, realloc failed");
147 }
148 return ret;
149}
150
151void *xcalloc(size_t nmemb, size_t size)
152{
153 void *ret;
154
155 if (unsigned_mult_overflows(nmemb, size)((nmemb) && (size) > (18446744073709551615ULL >>
((8 * sizeof(uintmax_t)) - (8 * sizeof(nmemb)))) / (nmemb)))
156 die("data too large to fit into virtual memory space");
157
158 memory_limit_check(size * nmemb, 0);
159 ret = calloc(nmemb, size);
160 if (!ret && (!nmemb || !size))
161 ret = calloc(1, 1);
162 if (!ret) {
163 try_to_free_routine(nmemb * size);
164 ret = calloc(nmemb, size);
165 if (!ret && (!nmemb || !size))
166 ret = calloc(1, 1);
167 if (!ret)
168 die("Out of memory, calloc failed");
169 }
170 return ret;
171}
172
173/*
174 * Limit size of IO chunks, because huge chunks only cause pain. OS X
175 * 64-bit is buggy, returning EINVAL if len >= INT_MAX; and even in
176 * the absence of bugs, large chunks can result in bad latencies when
177 * you decide to kill the process.
178 *
179 * We pick 8 MiB as our default, but if the platform defines SSIZE_MAX
180 * that is smaller than that, clip it to SSIZE_MAX, as a call to
181 * read(2) or write(2) larger than that is allowed to fail. As the last
182 * resort, we allow a port to pass via CFLAGS e.g. "-DMAX_IO_SIZE=value"
183 * to override this, if the definition of SSIZE_MAX given by the platform
184 * is broken.
185 */
186#ifndef MAX_IO_SIZE(8*1024*1024)
187# define MAX_IO_SIZE_DEFAULT(8*1024*1024) (8*1024*1024)
188# if defined(SSIZE_MAX9223372036854775807L) && (SSIZE_MAX9223372036854775807L < MAX_IO_SIZE_DEFAULT(8*1024*1024))
189# define MAX_IO_SIZE(8*1024*1024) SSIZE_MAX9223372036854775807L
190# else
191# define MAX_IO_SIZE(8*1024*1024) MAX_IO_SIZE_DEFAULT(8*1024*1024)
192# endif
193#endif
194
195/**
196 * xopen() is the same as open(), but it die()s if the open() fails.
197 */
198int xopen(const char *path, int oflag, ...)
199{
200 mode_t mode = 0;
201 va_list ap;
202
203 /*
204 * va_arg() will have undefined behavior if the specified type is not
205 * compatible with the argument type. Since integers are promoted to
206 * ints, we fetch the next argument as an int, and then cast it to a
207 * mode_t to avoid undefined behavior.
208 */
209 va_start(ap, oflag)__builtin_va_start(ap, oflag);
210 if (oflag & O_CREAT0x0200)
211 mode = va_arg(ap, int)__builtin_va_arg(ap, int);
212 va_end(ap)__builtin_va_end(ap);
213
214 for (;;) {
215 int fd = open(path, oflag, mode);
216 if (fd >= 0)
217 return fd;
218 if (errno(*__error()) == EINTR4)
219 continue;
220
221 if ((oflag & O_RDWR0x0002) == O_RDWR0x0002)
222 die_errno(_("could not open '%s' for reading and writing"), path);
223 else if ((oflag & O_WRONLY0x0001) == O_WRONLY0x0001)
224 die_errno(_("could not open '%s' for writing"), path);
225 else
226 die_errno(_("could not open '%s' for reading"), path);
227 }
228}
229
230static int handle_nonblock(int fd, short poll_events, int err)
231{
232 struct pollfd pfd;
233
234 if (err != EAGAIN35 && err != EWOULDBLOCK35)
235 return 0;
236
237 pfd.fd = fd;
238 pfd.events = poll_events;
239
240 /*
241 * no need to check for errors, here;
242 * a subsequent read/write will detect unrecoverable errors
243 */
244 poll(&pfd, 1, -1);
245 return 1;
246}
247
248/*
249 * xread() is the same a read(), but it automatically restarts read()
250 * operations with a recoverable error (EAGAIN and EINTR). xread()
251 * DOES NOT GUARANTEE that "len" bytes is read even if the data is available.
252 */
253ssize_t xread(int fd, void *buf, size_t len)
254{
255 ssize_t nr;
256 if (len > MAX_IO_SIZE(8*1024*1024))
257 len = MAX_IO_SIZE(8*1024*1024);
258 while (1) {
259 nr = read(fd, buf, len);
260 if (nr < 0) {
261 if (errno(*__error()) == EINTR4)
262 continue;
263 if (handle_nonblock(fd, POLLIN0x0001, errno(*__error())))
264 continue;
265 }
266 return nr;
267 }
268}
269
270/*
271 * xwrite() is the same a write(), but it automatically restarts write()
272 * operations with a recoverable error (EAGAIN and EINTR). xwrite() DOES NOT
273 * GUARANTEE that "len" bytes is written even if the operation is successful.
274 */
275ssize_t xwrite(int fd, const void *buf, size_t len)
276{
277 ssize_t nr;
278 if (len > MAX_IO_SIZE(8*1024*1024))
279 len = MAX_IO_SIZE(8*1024*1024);
280 while (1) {
281 nr = write(fd, buf, len);
282 if (nr < 0) {
283 if (errno(*__error()) == EINTR4)
284 continue;
285 if (handle_nonblock(fd, POLLOUT0x0004, errno(*__error())))
286 continue;
287 }
288
289 return nr;
290 }
291}
292
293/*
294 * xpread() is the same as pread(), but it automatically restarts pread()
295 * operations with a recoverable error (EAGAIN and EINTR). xpread() DOES
296 * NOT GUARANTEE that "len" bytes is read even if the data is available.
297 */
298ssize_t xpread(int fd, void *buf, size_t len, off_t offset)
299{
300 ssize_t nr;
301 if (len > MAX_IO_SIZE(8*1024*1024))
302 len = MAX_IO_SIZE(8*1024*1024);
303 while (1) {
304 nr = pread(fd, buf, len, offset);
305 if ((nr < 0) && (errno(*__error()) == EAGAIN35 || errno(*__error()) == EINTR4))
306 continue;
307 return nr;
308 }
309}
310
311ssize_t read_in_full(int fd, void *buf, size_t count)
312{
313 char *p = buf;
314 ssize_t total = 0;
315
316 while (count > 0) {
317 ssize_t loaded = xread(fd, p, count);
318 if (loaded < 0)
319 return -1;
320 if (loaded == 0)
321 return total;
322 count -= loaded;
323 p += loaded;
324 total += loaded;
325 }
326
327 return total;
328}
329
330ssize_t write_in_full(int fd, const void *buf, size_t count)
331{
332 const char *p = buf;
333 ssize_t total = 0;
334
335 while (count > 0) {
336 ssize_t written = xwrite(fd, p, count);
337 if (written < 0)
338 return -1;
339 if (!written) {
340 errno(*__error()) = ENOSPC28;
341 return -1;
342 }
343 count -= written;
344 p += written;
345 total += written;
346 }
347
348 return total;
349}
350
351ssize_t pread_in_full(int fd, void *buf, size_t count, off_t offset)
352{
353 char *p = buf;
354 ssize_t total = 0;
355
356 while (count > 0) {
357 ssize_t loaded = xpread(fd, p, count, offset);
358 if (loaded < 0)
359 return -1;
360 if (loaded == 0)
361 return total;
362 count -= loaded;
363 p += loaded;
364 total += loaded;
365 offset += loaded;
366 }
367
368 return total;
369}
370
371int xdup(int fd)
372{
373 int ret = dup(fd);
374 if (ret < 0)
375 die_errno("dup failed");
376 return ret;
377}
378
379/**
380 * xfopen() is the same as fopen(), but it die()s if the fopen() fails.
381 */
382FILE *xfopen(const char *path, const char *mode)
383{
384 for (;;) {
385 FILE *fp = fopen(path, mode);
386 if (fp)
387 return fp;
388 if (errno(*__error()) == EINTR4)
389 continue;
390
391 if (*mode && mode[1] == '+')
392 die_errno(_("could not open '%s' for reading and writing"), path);
393 else if (*mode == 'w' || *mode == 'a')
394 die_errno(_("could not open '%s' for writing"), path);
395 else
396 die_errno(_("could not open '%s' for reading"), path);
397 }
398}
399
400FILE *xfdopen(int fd, const char *mode)
401{
402 FILE *stream = fdopen(fd, mode);
403 if (stream == NULL((void*)0))
404 die_errno("Out of memory? fdopen failed");
405 return stream;
406}
407
408FILE *fopen_for_writing(const char *path)
409{
410 FILE *ret = fopen(path, "w");
411
412 if (!ret && errno(*__error()) == EPERM1) {
413 if (!unlink(path))
414 ret = fopen(path, "w");
415 else
416 errno(*__error()) = EPERM1;
417 }
418 return ret;
419}
420
421int xmkstemp(char *template)
422{
423 int fd;
424 char origtemplate[PATH_MAX1024];
425 strlcpy(origtemplate, template, sizeof(origtemplate))__builtin___strlcpy_chk (origtemplate, template, sizeof(origtemplate
), __builtin_object_size (origtemplate, 2 > 1 ? 1 : 0));
426
427 fd = mkstemp(template);
428 if (fd < 0) {
429 int saved_errno = errno(*__error());
430 const char *nonrelative_template;
431
432 if (strlen(template) != strlen(origtemplate))
433 template = origtemplate;
434
435 nonrelative_template = absolute_path(template);
436 errno(*__error()) = saved_errno;
437 die_errno("Unable to create temporary file '%s'",
438 nonrelative_template);
439 }
440 return fd;
441}
442
443/* git_mkstemp() - create tmp file honoring TMPDIR variable */
444int git_mkstemp(char *path, size_t len, const char *template)
445{
446 const char *tmp;
447 size_t n;
448
449 tmp = getenv("TMPDIR");
450 if (!tmp)
451 tmp = "/tmp";
452 n = snprintf(path, len, "%s/%s", tmp, template)__builtin___snprintf_chk (path, len, 0, __builtin_object_size
(path, 2 > 1 ? 1 : 0), "%s/%s", tmp, template);
453 if (len <= n) {
454 errno(*__error()) = ENAMETOOLONG63;
455 return -1;
456 }
457 return mkstemp(path);
458}
459
460/* Adapted from libiberty's mkstemp.c. */
461
462#undef TMP_MAX16384
463#define TMP_MAX16384 16384
464
465int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
466{
467 static const char letters[] =
468 "abcdefghijklmnopqrstuvwxyz"
469 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
470 "0123456789";
471 static const int num_letters = 62;
472 uint64_t value;
473 struct timeval tv;
474 char *template;
475 size_t len;
476 int fd, count;
477
478 len = strlen(pattern);
479
480 if (len < 6 + suffix_len) {
481 errno(*__error()) = EINVAL22;
482 return -1;
483 }
484
485 if (strncmp(&pattern[len - 6 - suffix_len], "XXXXXX", 6)) {
486 errno(*__error()) = EINVAL22;
487 return -1;
488 }
489
490 /*
491 * Replace pattern's XXXXXX characters with randomness.
492 * Try TMP_MAX different filenames.
493 */
494 gettimeofday(&tv, NULL((void*)0));
495 value = ((size_t)(tv.tv_usec << 16)) ^ tv.tv_sec ^ getpid();
496 template = &pattern[len - 6 - suffix_len];
497 for (count = 0; count < TMP_MAX16384; ++count) {
498 uint64_t v = value;
499 /* Fill in the random bits. */
500 template[0] = letters[v % num_letters]; v /= num_letters;
501 template[1] = letters[v % num_letters]; v /= num_letters;
502 template[2] = letters[v % num_letters]; v /= num_letters;
503 template[3] = letters[v % num_letters]; v /= num_letters;
504 template[4] = letters[v % num_letters]; v /= num_letters;
505 template[5] = letters[v % num_letters]; v /= num_letters;
Value stored to 'v' is never read
506
507 fd = open(pattern, O_CREAT0x0200 | O_EXCL0x0800 | O_RDWR0x0002, mode);
508 if (fd >= 0)
509 return fd;
510 /*
511 * Fatal error (EPERM, ENOSPC etc).
512 * It doesn't make sense to loop.
513 */
514 if (errno(*__error()) != EEXIST17)
515 break;
516 /*
517 * This is a random value. It is only necessary that
518 * the next TMP_MAX values generated by adding 7777 to
519 * VALUE are different with (module 2^32).
520 */
521 value += 7777;
522 }
523 /* We return the null string if we can't find a unique file name. */
524 pattern[0] = '\0';
525 return -1;
526}
527
528int git_mkstemp_mode(char *pattern, int mode)
529{
530 /* mkstemp is just mkstemps with no suffix */
531 return git_mkstemps_mode(pattern, 0, mode);
532}
533
534#ifdef NO_MKSTEMPS
535int gitmkstemps(char *pattern, int suffix_len)
536{
537 return git_mkstemps_mode(pattern, suffix_len, 0600);
538}
539#endif
540
541int xmkstemp_mode(char *template, int mode)
542{
543 int fd;
544 char origtemplate[PATH_MAX1024];
545 strlcpy(origtemplate, template, sizeof(origtemplate))__builtin___strlcpy_chk (origtemplate, template, sizeof(origtemplate
), __builtin_object_size (origtemplate, 2 > 1 ? 1 : 0));
546
547 fd = git_mkstemp_mode(template, mode);
548 if (fd < 0) {
549 int saved_errno = errno(*__error());
550 const char *nonrelative_template;
551
552 if (!template[0])
553 template = origtemplate;
554
555 nonrelative_template = absolute_path(template);
556 errno(*__error()) = saved_errno;
557 die_errno("Unable to create temporary file '%s'",
558 nonrelative_template);
559 }
560 return fd;
561}
562
563static int warn_if_unremovable(const char *op, const char *file, int rc)
564{
565 int err;
566 if (!rc || errno(*__error()) == ENOENT2)
567 return 0;
568 err = errno(*__error());
569 warning_errno("unable to %s %s", op, file);
570 errno(*__error()) = err;
571 return rc;
572}
573
574int unlink_or_msg(const char *file, struct strbuf *err)
575{
576 int rc = unlink(file);
577
578 assert(err)(__builtin_expect(!(err), 0) ? __assert_rtn(__func__, "wrapper.c"
, 578, "err") : (void)0);
579
580 if (!rc || errno(*__error()) == ENOENT2)
581 return 0;
582
583 strbuf_addf(err, "unable to unlink %s: %s",
584 file, strerror(errno(*__error())));
585 return -1;
586}
587
588int unlink_or_warn(const char *file)
589{
590 return warn_if_unremovable("unlink", file, unlink(file));
591}
592
593int rmdir_or_warn(const char *file)
594{
595 return warn_if_unremovable("rmdir", file, rmdir(file));
596}
597
598int remove_or_warn(unsigned int mode, const char *file)
599{
600 return S_ISGITLINK(mode)(((mode) & 0170000) == 0160000) ? rmdir_or_warn(file) : unlink_or_warn(file);
601}
602
603void warn_on_inaccessible(const char *path)
604{
605 warning_errno(_("unable to access '%s'"), path);
606}
607
608static int access_error_is_ok(int err, unsigned flag)
609{
610 return err == ENOENT2 || err == ENOTDIR20 ||
611 ((flag & ACCESS_EACCES_OK(1U << 0)) && err == EACCES13);
612}
613
614int access_or_warn(const char *path, int mode, unsigned flag)
615{
616 int ret = access(path, mode);
617 if (ret && !access_error_is_ok(errno(*__error()), flag))
618 warn_on_inaccessible(path);
619 return ret;
620}
621
622int access_or_die(const char *path, int mode, unsigned flag)
623{
624 int ret = access(path, mode);
625 if (ret && !access_error_is_ok(errno(*__error()), flag))
626 die_errno(_("unable to access '%s'"), path);
627 return ret;
628}
629
630char *xgetcwd(void)
631{
632 struct strbuf sb = STRBUF_INIT{ 0, 0, strbuf_slopbuf };
633 if (strbuf_getcwd(&sb))
634 die_errno(_("unable to get current working directory"));
635 return strbuf_detach(&sb, NULL((void*)0));
636}
637
638int xsnprintf(char *dst, size_t max, const char *fmt, ...)
639{
640 va_list ap;
641 int len;
642
643 va_start(ap, fmt)__builtin_va_start(ap, fmt);
644 len = vsnprintf(dst, max, fmt, ap)__builtin___vsnprintf_chk (dst, max, 0, __builtin_object_size
(dst, 2 > 1 ? 1 : 0), fmt, ap);
645 va_end(ap)__builtin_va_end(ap);
646
647 if (len < 0)
648 die("BUG: your snprintf is broken");
649 if (len >= max)
650 die("BUG: attempt to snprintf into too-small buffer");
651 return len;
652}
653
654void write_file_buf(const char *path, const char *buf, size_t len)
655{
656 int fd = xopen(path, O_WRONLY0x0001 | O_CREAT0x0200 | O_TRUNC0x0400, 0666);
657 if (write_in_full(fd, buf, len) != len)
658 die_errno(_("could not write to %s"), path);
659 if (close(fd))
660 die_errno(_("could not close %s"), path);
661}
662
663void write_file(const char *path, const char *fmt, ...)
664{
665 va_list params;
666 struct strbuf sb = STRBUF_INIT{ 0, 0, strbuf_slopbuf };
667
668 va_start(params, fmt)__builtin_va_start(params, fmt);
669 strbuf_vaddf(&sb, fmt, params);
670 va_end(params)__builtin_va_end(params);
671
672 strbuf_complete_line(&sb);
673
674 write_file_buf(path, sb.buf, sb.len);
675 strbuf_release(&sb);
676}
677
678void sleep_millisec(int millisec)
679{
680 poll(NULL((void*)0), 0, millisec);
681}