git-describe: use find_unique_abbrev()
[git.git] / update-index.c
1 /*
2  * GIT - The information manager from hell
3  *
4  * Copyright (C) Linus Torvalds, 2005
5  */
6 #include "cache.h"
7 #include "strbuf.h"
8 #include "quote.h"
9
10 /*
11  * Default to not allowing changes to the list of files. The
12  * tool doesn't actually care, but this makes it harder to add
13  * files to the revision control by mistake by doing something
14  * like "git-update-index *" and suddenly having all the object
15  * files be revision controlled.
16  */
17 static int allow_add;
18 static int allow_remove;
19 static int allow_replace;
20 static int allow_unmerged; /* --refresh needing merge is not error */
21 static int not_new; /* --refresh not having working tree files is not error */
22 static int quiet; /* --refresh needing update is not error */
23 static int info_only;
24 static int force_remove;
25 static int verbose;
26
27 /* Three functions to allow overloaded pointer return; see linux/err.h */
28 static inline void *ERR_PTR(long error)
29 {
30         return (void *) error;
31 }
32
33 static inline long PTR_ERR(const void *ptr)
34 {
35         return (long) ptr;
36 }
37
38 static inline long IS_ERR(const void *ptr)
39 {
40         return (unsigned long)ptr > (unsigned long)-1000L;
41 }
42
43 static void report(const char *fmt, ...)
44 {
45         va_list vp;
46
47         if (!verbose)
48                 return;
49
50         va_start(vp, fmt);
51         vprintf(fmt, vp);
52         putchar('\n');
53         va_end(vp);
54 }
55
56 static int add_file_to_cache(const char *path)
57 {
58         int size, namelen, option, status;
59         struct cache_entry *ce;
60         struct stat st;
61
62         status = lstat(path, &st);
63         if (status < 0 || S_ISDIR(st.st_mode)) {
64                 /* When we used to have "path" and now we want to add
65                  * "path/file", we need a way to remove "path" before
66                  * being able to add "path/file".  However,
67                  * "git-update-index --remove path" would not work.
68                  * --force-remove can be used but this is more user
69                  * friendly, especially since we can do the opposite
70                  * case just fine without --force-remove.
71                  */
72                 if (status == 0 || (errno == ENOENT || errno == ENOTDIR)) {
73                         if (allow_remove) {
74                                 if (remove_file_from_cache(path))
75                                         return error("%s: cannot remove from the index",
76                                                      path);
77                                 else
78                                         return 0;
79                         } else if (status < 0) {
80                                 return error("%s: does not exist and --remove not passed",
81                                              path);
82                         }
83                 }
84                 if (0 == status)
85                         return error("%s: is a directory - add files inside instead",
86                                      path);
87                 else
88                         return error("lstat(\"%s\"): %s", path,
89                                      strerror(errno));
90         }
91
92         namelen = strlen(path);
93         size = cache_entry_size(namelen);
94         ce = xmalloc(size);
95         memset(ce, 0, size);
96         memcpy(ce->name, path, namelen);
97         fill_stat_cache_info(ce, &st);
98
99         ce->ce_mode = create_ce_mode(st.st_mode);
100         if (!trust_executable_bit) {
101                 /* If there is an existing entry, pick the mode bits
102                  * from it.
103                  */
104                 int pos = cache_name_pos(path, namelen);
105                 if (0 <= pos)
106                         ce->ce_mode = active_cache[pos]->ce_mode;
107         }
108         ce->ce_flags = htons(namelen);
109
110         if (index_path(ce->sha1, path, &st, !info_only))
111                 return -1;
112         option = allow_add ? ADD_CACHE_OK_TO_ADD : 0;
113         option |= allow_replace ? ADD_CACHE_OK_TO_REPLACE : 0;
114         if (add_cache_entry(ce, option))
115                 return error("%s: cannot add to the index - missing --add option?",
116                              path);
117         return 0;
118 }
119
120 /*
121  * "refresh" does not calculate a new sha1 file or bring the
122  * cache up-to-date for mode/content changes. But what it
123  * _does_ do is to "re-match" the stat information of a file
124  * with the cache, so that you can refresh the cache for a
125  * file that hasn't been changed but where the stat entry is
126  * out of date.
127  *
128  * For example, you'd want to do this after doing a "git-read-tree",
129  * to link up the stat cache details with the proper files.
130  */
131 static struct cache_entry *refresh_entry(struct cache_entry *ce)
132 {
133         struct stat st;
134         struct cache_entry *updated;
135         int changed, size;
136
137         if (lstat(ce->name, &st) < 0)
138                 return ERR_PTR(-errno);
139
140         changed = ce_match_stat(ce, &st);
141         if (!changed)
142                 return NULL;
143
144         if (ce_modified(ce, &st))
145                 return ERR_PTR(-EINVAL);
146
147         size = ce_size(ce);
148         updated = xmalloc(size);
149         memcpy(updated, ce, size);
150         fill_stat_cache_info(updated, &st);
151         return updated;
152 }
153
154 static int refresh_cache(void)
155 {
156         int i;
157         int has_errors = 0;
158
159         for (i = 0; i < active_nr; i++) {
160                 struct cache_entry *ce, *new;
161                 ce = active_cache[i];
162                 if (ce_stage(ce)) {
163                         while ((i < active_nr) &&
164                                ! strcmp(active_cache[i]->name, ce->name))
165                                 i++;
166                         i--;
167                         if (allow_unmerged)
168                                 continue;
169                         printf("%s: needs merge\n", ce->name);
170                         has_errors = 1;
171                         continue;
172                 }
173
174                 new = refresh_entry(ce);
175                 if (!new)
176                         continue;
177                 if (IS_ERR(new)) {
178                         if (not_new && PTR_ERR(new) == -ENOENT)
179                                 continue;
180                         if (quiet)
181                                 continue;
182                         printf("%s: needs update\n", ce->name);
183                         has_errors = 1;
184                         continue;
185                 }
186                 active_cache_changed = 1;
187                 /* You can NOT just free active_cache[i] here, since it
188                  * might not be necessarily malloc()ed but can also come
189                  * from mmap(). */
190                 active_cache[i] = new;
191         }
192         return has_errors;
193 }
194
195 /*
196  * We fundamentally don't like some paths: we don't want
197  * dot or dot-dot anywhere, and for obvious reasons don't
198  * want to recurse into ".git" either.
199  *
200  * Also, we don't want double slashes or slashes at the
201  * end that can make pathnames ambiguous.
202  */
203 static int verify_dotfile(const char *rest)
204 {
205         /*
206          * The first character was '.', but that
207          * has already been discarded, we now test
208          * the rest.
209          */
210         switch (*rest) {
211         /* "." is not allowed */
212         case '\0': case '/':
213                 return 0;
214
215         /*
216          * ".git" followed by  NUL or slash is bad. This
217          * shares the path end test with the ".." case.
218          */
219         case 'g':
220                 if (rest[1] != 'i')
221                         break;
222                 if (rest[2] != 't')
223                         break;
224                 rest += 2;
225         /* fallthrough */
226         case '.':
227                 if (rest[1] == '\0' || rest[1] == '/')
228                         return 0;
229         }
230         return 1;
231 }
232
233 static int verify_path(const char *path)
234 {
235         char c;
236
237         goto inside;
238         for (;;) {
239                 if (!c)
240                         return 1;
241                 if (c == '/') {
242 inside:
243                         c = *path++;
244                         switch (c) {
245                         default:
246                                 continue;
247                         case '/': case '\0':
248                                 break;
249                         case '.':
250                                 if (verify_dotfile(path))
251                                         continue;
252                         }
253                         return 0;
254                 }
255                 c = *path++;
256         }
257 }
258
259 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
260                          const char *path, int stage)
261 {
262         int size, len, option;
263         struct cache_entry *ce;
264
265         if (!verify_path(path))
266                 return -1;
267
268         len = strlen(path);
269         size = cache_entry_size(len);
270         ce = xmalloc(size);
271         memset(ce, 0, size);
272
273         memcpy(ce->sha1, sha1, 20);
274         memcpy(ce->name, path, len);
275         ce->ce_flags = create_ce_flags(len, stage);
276         ce->ce_mode = create_ce_mode(mode);
277         option = allow_add ? ADD_CACHE_OK_TO_ADD : 0;
278         option |= allow_replace ? ADD_CACHE_OK_TO_REPLACE : 0;
279         if (add_cache_entry(ce, option))
280                 return error("%s: cannot add to the index - missing --add option?",
281                              path);
282         report("add '%s'", path);
283         return 0;
284 }
285
286 static int chmod_path(int flip, const char *path)
287 {
288         int pos;
289         struct cache_entry *ce;
290         unsigned int mode;
291
292         pos = cache_name_pos(path, strlen(path));
293         if (pos < 0)
294                 return -1;
295         ce = active_cache[pos];
296         mode = ntohl(ce->ce_mode);
297         if (!S_ISREG(mode))
298                 return -1;
299         switch (flip) {
300         case '+':
301                 ce->ce_mode |= htonl(0111); break;
302         case '-':
303                 ce->ce_mode &= htonl(~0111); break;
304         default:
305                 return -1;
306         }
307         active_cache_changed = 1;
308         return 0;
309 }
310
311 static struct cache_file cache_file;
312
313 static void update_one(const char *path, const char *prefix, int prefix_length)
314 {
315         const char *p = prefix_path(prefix, prefix_length, path);
316         if (!verify_path(p)) {
317                 fprintf(stderr, "Ignoring path %s\n", path);
318                 return;
319         }
320         if (force_remove) {
321                 if (remove_file_from_cache(p))
322                         die("git-update-index: unable to remove %s", path);
323                 report("remove '%s'", path);
324                 return;
325         }
326         if (add_file_to_cache(p))
327                 die("Unable to process file %s", path);
328         report("add '%s'", path);
329 }
330
331 static void read_index_info(int line_termination)
332 {
333         struct strbuf buf;
334         strbuf_init(&buf);
335         while (1) {
336                 char *ptr, *tab;
337                 char *path_name;
338                 unsigned char sha1[20];
339                 unsigned int mode;
340                 int stage;
341
342                 /* This reads lines formatted in one of three formats:
343                  *
344                  * (1) mode         SP sha1          TAB path
345                  * The first format is what "git-apply --index-info"
346                  * reports, and used to reconstruct a partial tree
347                  * that is used for phony merge base tree when falling
348                  * back on 3-way merge.
349                  *
350                  * (2) mode SP type SP sha1          TAB path
351                  * The second format is to stuff git-ls-tree output
352                  * into the index file.
353                  * 
354                  * (3) mode         SP sha1 SP stage TAB path
355                  * This format is to put higher order stages into the
356                  * index file and matches git-ls-files --stage output.
357                  */
358                 read_line(&buf, stdin, line_termination);
359                 if (buf.eof)
360                         break;
361
362                 mode = strtoul(buf.buf, &ptr, 8);
363                 if (ptr == buf.buf || *ptr != ' ')
364                         goto bad_line;
365
366                 tab = strchr(ptr, '\t');
367                 if (!tab || tab - ptr < 41)
368                         goto bad_line;
369
370                 if (tab[-2] == ' ' && '1' <= tab[-1] && tab[-1] <= '3') {
371                         stage = tab[-1] - '0';
372                         ptr = tab + 1; /* point at the head of path */
373                         tab = tab - 2; /* point at tail of sha1 */
374                 }
375                 else {
376                         stage = 0;
377                         ptr = tab + 1; /* point at the head of path */
378                 }
379
380                 if (get_sha1_hex(tab - 40, sha1) || tab[-41] != ' ')
381                         goto bad_line;
382
383                 if (line_termination && ptr[0] == '"')
384                         path_name = unquote_c_style(ptr, NULL);
385                 else
386                         path_name = ptr;
387
388                 if (!verify_path(path_name)) {
389                         fprintf(stderr, "Ignoring path %s\n", path_name);
390                         if (path_name != ptr)
391                                 free(path_name);
392                         continue;
393                 }
394
395                 if (!mode) {
396                         /* mode == 0 means there is no such path -- remove */
397                         if (remove_file_from_cache(path_name))
398                                 die("git-update-index: unable to remove %s",
399                                     ptr);
400                 }
401                 else {
402                         /* mode ' ' sha1 '\t' name
403                          * ptr[-1] points at tab,
404                          * ptr[-41] is at the beginning of sha1
405                          */
406                         ptr[-42] = ptr[-1] = 0;
407                         if (add_cacheinfo(mode, sha1, path_name, stage))
408                                 die("git-update-index: unable to update %s",
409                                     path_name);
410                 }
411                 if (path_name != ptr)
412                         free(path_name);
413                 continue;
414
415         bad_line:
416                 die("malformed index info %s", buf.buf);
417         }
418 }
419
420 static const char update_index_usage[] =
421 "git-update-index [-q] [--add] [--replace] [--remove] [--unmerged] [--refresh] [--cacheinfo] [--chmod=(+|-)x] [--info-only] [--force-remove] [--stdin] [--index-info] [--ignore-missing] [-z] [--verbose] [--] <file>...";
422
423 int main(int argc, const char **argv)
424 {
425         int i, newfd, entries, has_errors = 0, line_termination = '\n';
426         int allow_options = 1;
427         int read_from_stdin = 0;
428         const char *prefix = setup_git_directory();
429         int prefix_length = prefix ? strlen(prefix) : 0;
430
431         git_config(git_default_config);
432
433         newfd = hold_index_file_for_update(&cache_file, get_index_file());
434         if (newfd < 0)
435                 die("unable to create new cachefile");
436
437         entries = read_cache();
438         if (entries < 0)
439                 die("cache corrupted");
440
441         for (i = 1 ; i < argc; i++) {
442                 const char *path = argv[i];
443
444                 if (allow_options && *path == '-') {
445                         if (!strcmp(path, "--")) {
446                                 allow_options = 0;
447                                 continue;
448                         }
449                         if (!strcmp(path, "-q")) {
450                                 quiet = 1;
451                                 continue;
452                         }
453                         if (!strcmp(path, "--add")) {
454                                 allow_add = 1;
455                                 continue;
456                         }
457                         if (!strcmp(path, "--replace")) {
458                                 allow_replace = 1;
459                                 continue;
460                         }
461                         if (!strcmp(path, "--remove")) {
462                                 allow_remove = 1;
463                                 continue;
464                         }
465                         if (!strcmp(path, "--unmerged")) {
466                                 allow_unmerged = 1;
467                                 continue;
468                         }
469                         if (!strcmp(path, "--refresh")) {
470                                 has_errors |= refresh_cache();
471                                 continue;
472                         }
473                         if (!strcmp(path, "--cacheinfo")) {
474                                 unsigned char sha1[20];
475                                 unsigned int mode;
476
477                                 if (i+3 >= argc)
478                                         die("git-update-index: --cacheinfo <mode> <sha1> <path>");
479
480                                 if ((sscanf(argv[i+1], "%o", &mode) != 1) ||
481                                     get_sha1_hex(argv[i+2], sha1) ||
482                                     add_cacheinfo(mode, sha1, argv[i+3], 0))
483                                         die("git-update-index: --cacheinfo"
484                                             " cannot add %s", argv[i+3]);
485                                 i += 3;
486                                 continue;
487                         }
488                         if (!strcmp(path, "--chmod=-x") ||
489                             !strcmp(path, "--chmod=+x")) {
490                                 if (argc <= i+1)
491                                         die("git-update-index: %s <path>", path);
492                                 if (chmod_path(path[8], argv[++i]))
493                                         die("git-update-index: %s cannot chmod %s", path, argv[i]);
494                                 continue;
495                         }
496                         if (!strcmp(path, "--info-only")) {
497                                 info_only = 1;
498                                 continue;
499                         }
500                         if (!strcmp(path, "--force-remove")) {
501                                 force_remove = 1;
502                                 continue;
503                         }
504                         if (!strcmp(path, "-z")) {
505                                 line_termination = 0;
506                                 continue;
507                         }
508                         if (!strcmp(path, "--stdin")) {
509                                 if (i != argc - 1)
510                                         die("--stdin must be at the end");
511                                 read_from_stdin = 1;
512                                 break;
513                         }
514                         if (!strcmp(path, "--index-info")) {
515                                 allow_add = allow_replace = allow_remove = 1;
516                                 read_index_info(line_termination);
517                                 continue;
518                         }
519                         if (!strcmp(path, "--ignore-missing")) {
520                                 not_new = 1;
521                                 continue;
522                         }
523                         if (!strcmp(path, "--verbose")) {
524                                 verbose = 1;
525                                 continue;
526                         }
527                         if (!strcmp(path, "-h") || !strcmp(path, "--help"))
528                                 usage(update_index_usage);
529                         die("unknown option %s", path);
530                 }
531                 update_one(path, prefix, prefix_length);
532         }
533         if (read_from_stdin) {
534                 struct strbuf buf;
535                 strbuf_init(&buf);
536                 while (1) {
537                         read_line(&buf, stdin, line_termination);
538                         if (buf.eof)
539                                 break;
540                         update_one(buf.buf, prefix, prefix_length);
541                 }
542         }
543         if (active_cache_changed) {
544                 if (write_cache(newfd, active_cache, active_nr) ||
545                     commit_index_file(&cache_file))
546                         die("Unable to write new cachefile");
547         }
548
549         return has_errors ? 1 : 0;
550 }