Merge branch 'maint'
[git] / diff-lib.c
1 /*
2  * Copyright (C) 2005 Junio C Hamano
3  */
4 #include "cache.h"
5 #include "quote.h"
6 #include "commit.h"
7 #include "diff.h"
8 #include "diffcore.h"
9 #include "revision.h"
10 #include "cache-tree.h"
11 #include "path-list.h"
12
13 /*
14  * diff-files
15  */
16
17 static int read_directory(const char *path, struct path_list *list)
18 {
19         DIR *dir;
20         struct dirent *e;
21
22         if (!(dir = opendir(path)))
23                 return error("Could not open directory %s", path);
24
25         while ((e = readdir(dir)))
26                 if (strcmp(".", e->d_name) && strcmp("..", e->d_name))
27                         path_list_insert(xstrdup(e->d_name), list);
28
29         closedir(dir);
30         return 0;
31 }
32
33 static int queue_diff(struct diff_options *o,
34                 const char *name1, const char *name2)
35 {
36         struct stat st;
37         int mode1 = 0, mode2 = 0;
38
39         if (name1) {
40                 if (stat(name1, &st))
41                         return error("Could not access '%s'", name1);
42                 mode1 = st.st_mode;
43         }
44         if (name2) {
45                 if (stat(name2, &st))
46                         return error("Could not access '%s'", name2);
47                 mode2 = st.st_mode;
48         }
49
50         if (mode1 && mode2 && S_ISDIR(mode1) != S_ISDIR(mode2))
51                 return error("file/directory conflict: %s, %s", name1, name2);
52
53         if (S_ISDIR(mode1) || S_ISDIR(mode2)) {
54                 char buffer1[PATH_MAX], buffer2[PATH_MAX];
55                 struct path_list p1 = {NULL, 0, 0, 1}, p2 = {NULL, 0, 0, 1};
56                 int len1 = 0, len2 = 0, i1, i2, ret = 0;
57
58                 if (name1 && read_directory(name1, &p1))
59                         return -1;
60                 if (name2 && read_directory(name2, &p2)) {
61                         path_list_clear(&p1, 0);
62                         return -1;
63                 }
64
65                 if (name1) {
66                         len1 = strlen(name1);
67                         if (len1 > 0 && name1[len1 - 1] == '/')
68                                 len1--;
69                         memcpy(buffer1, name1, len1);
70                         buffer1[len1++] = '/';
71                 }
72
73                 if (name2) {
74                         len2 = strlen(name2);
75                         if (len2 > 0 && name2[len2 - 1] == '/')
76                                 len2--;
77                         memcpy(buffer2, name2, len2);
78                         buffer2[len2++] = '/';
79                 }
80
81                 for (i1 = i2 = 0; !ret && (i1 < p1.nr || i2 < p2.nr); ) {
82                         const char *n1, *n2;
83                         int comp;
84
85                         if (i1 == p1.nr)
86                                 comp = 1;
87                         else if (i2 == p2.nr)
88                                 comp = -1;
89                         else
90                                 comp = strcmp(p1.items[i1].path,
91                                         p2.items[i2].path);
92
93                         if (comp > 0)
94                                 n1 = NULL;
95                         else {
96                                 n1 = buffer1;
97                                 strncpy(buffer1 + len1, p1.items[i1++].path,
98                                                 PATH_MAX - len1);
99                         }
100
101                         if (comp < 0)
102                                 n2 = NULL;
103                         else {
104                                 n2 = buffer2;
105                                 strncpy(buffer2 + len2, p2.items[i2++].path,
106                                                 PATH_MAX - len2);
107                         }
108
109                         ret = queue_diff(o, n1, n2);
110                 }
111                 path_list_clear(&p1, 0);
112                 path_list_clear(&p2, 0);
113
114                 return ret;
115         } else {
116                 struct diff_filespec *d1, *d2;
117
118                 if (o->reverse_diff) {
119                         unsigned tmp;
120                         const char *tmp_c;
121                         tmp = mode1; mode1 = mode2; mode2 = tmp;
122                         tmp_c = name1; name1 = name2; name2 = tmp_c;
123                 }
124
125                 if (!name1)
126                         name1 = "/dev/null";
127                 if (!name2)
128                         name2 = "/dev/null";
129                 d1 = alloc_filespec(name1);
130                 d2 = alloc_filespec(name2);
131                 fill_filespec(d1, null_sha1, mode1);
132                 fill_filespec(d2, null_sha1, mode2);
133
134                 diff_queue(&diff_queued_diff, d1, d2);
135                 return 0;
136         }
137 }
138
139 static int is_in_index(const char *path)
140 {
141         int len = strlen(path);
142         int pos = cache_name_pos(path, len);
143         char c;
144
145         if (pos < 0)
146                 return 0;
147         if (strncmp(active_cache[pos]->name, path, len))
148                 return 0;
149         c = active_cache[pos]->name[len];
150         return c == '\0' || c == '/';
151 }
152
153 static int handle_diff_files_args(struct rev_info *revs,
154                 int argc, const char **argv, int *silent)
155 {
156         *silent = 0;
157
158         /* revs->max_count == -2 means --no-index */
159         while (1 < argc && argv[1][0] == '-') {
160                 if (!strcmp(argv[1], "--base"))
161                         revs->max_count = 1;
162                 else if (!strcmp(argv[1], "--ours"))
163                         revs->max_count = 2;
164                 else if (!strcmp(argv[1], "--theirs"))
165                         revs->max_count = 3;
166                 else if (!strcmp(argv[1], "-n") ||
167                                 !strcmp(argv[1], "--no-index"))
168                         revs->max_count = -2;
169                 else if (!strcmp(argv[1], "-q"))
170                         *silent = 1;
171                 else
172                         return error("invalid option: %s", argv[1]);
173                 argv++; argc--;
174         }
175
176         if (revs->max_count == -1 && revs->diffopt.nr_paths == 2) {
177                 /*
178                  * If two files are specified, and at least one is untracked,
179                  * default to no-index.
180                  */
181                 read_cache();
182                 if (!is_in_index(revs->diffopt.paths[0]) ||
183                                         !is_in_index(revs->diffopt.paths[1]))
184                         revs->max_count = -2;
185         }
186
187         /*
188          * Make sure there are NO revision (i.e. pending object) parameter,
189          * rev.max_count is reasonable (0 <= n <= 3),
190          * there is no other revision filtering parameters.
191          */
192         if (revs->pending.nr || revs->max_count > 3 ||
193             revs->min_age != -1 || revs->max_age != -1)
194                 return error("no revision allowed with diff-files");
195
196         if (revs->max_count == -1 &&
197             (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
198                 revs->combine_merges = revs->dense_combined_merges = 1;
199
200         return 0;
201 }
202
203 static int is_outside_repo(const char *path, int nongit, const char *prefix)
204 {
205         int i;
206         if (nongit || !strcmp(path, "-") || path[0] == '/')
207                 return 1;
208         if (prefixcmp(path, "../"))
209                 return 0;
210         if (!prefix)
211                 return 1;
212         for (i = strlen(prefix); !prefixcmp(path, "../"); ) {
213                 while (i > 0 && prefix[i - 1] != '/')
214                         i--;
215                 if (--i < 0)
216                         return 1;
217                 path += 3;
218         }
219         return 0;
220 }
221
222 int setup_diff_no_index(struct rev_info *revs,
223                 int argc, const char ** argv, int nongit, const char *prefix)
224 {
225         int i;
226         for (i = 1; i < argc; i++)
227                 if (argv[i][0] != '-')
228                         break;
229                 else if (!strcmp(argv[i], "--")) {
230                         i++;
231                         break;
232                 } else if (i < argc - 3 && !strcmp(argv[i], "--no-index")) {
233                         i = argc - 3;
234                         break;
235                 }
236         if (argc != i + 2 || (!is_outside_repo(argv[i + 1], nongit, prefix) &&
237                                 !is_outside_repo(argv[i], nongit, prefix)))
238                 return -1;
239
240         diff_setup(&revs->diffopt);
241         for (i = 1; i < argc - 2; )
242                 if (!strcmp(argv[i], "--no-index"))
243                         i++;
244                 else {
245                         int j = diff_opt_parse(&revs->diffopt,
246                                         argv + i, argc - i);
247                         if (!j)
248                                 die("invalid diff option/value: %s", argv[i]);
249                         i += j;
250                 }
251
252         if (prefix) {
253                 int len = strlen(prefix);
254
255                 revs->diffopt.paths = xcalloc(2, sizeof(char*));
256                 for (i = 0; i < 2; i++) {
257                         const char *p;
258                         p = prefix_filename(prefix, len, argv[argc - 2 + i]);
259                         revs->diffopt.paths[i] = xstrdup(p);
260                 }
261         }
262         else
263                 revs->diffopt.paths = argv + argc - 2;
264         revs->diffopt.nr_paths = 2;
265         revs->max_count = -2;
266         return 0;
267 }
268
269 int run_diff_files_cmd(struct rev_info *revs, int argc, const char **argv)
270 {
271         int silent_on_removed;
272
273         if (handle_diff_files_args(revs, argc, argv, &silent_on_removed))
274                 return -1;
275
276         if (revs->max_count == -2) {
277                 if (revs->diffopt.nr_paths != 2)
278                         return error("need two files/directories with --no-index");
279                 if (queue_diff(&revs->diffopt, revs->diffopt.paths[0],
280                                 revs->diffopt.paths[1]))
281                         return -1;
282                 diffcore_std(&revs->diffopt);
283                 diff_flush(&revs->diffopt);
284                 /*
285                  * The return code for --no-index imitates diff(1):
286                  * 0 = no changes, 1 = changes, else error
287                  */
288                 return revs->diffopt.found_changes;
289         }
290
291         if (read_cache() < 0) {
292                 perror("read_cache");
293                 return -1;
294         }
295         return run_diff_files(revs, silent_on_removed);
296 }
297
298 int run_diff_files(struct rev_info *revs, int silent_on_removed)
299 {
300         int entries, i;
301         int diff_unmerged_stage = revs->max_count;
302
303         if (diff_unmerged_stage < 0)
304                 diff_unmerged_stage = 2;
305         entries = active_nr;
306         for (i = 0; i < entries; i++) {
307                 struct stat st;
308                 unsigned int oldmode, newmode;
309                 struct cache_entry *ce = active_cache[i];
310                 int changed;
311
312                 if (!ce_path_match(ce, revs->prune_data))
313                         continue;
314
315                 if (ce_stage(ce)) {
316                         struct combine_diff_path *dpath;
317                         int num_compare_stages = 0;
318                         size_t path_len;
319
320                         path_len = ce_namelen(ce);
321
322                         dpath = xmalloc(combine_diff_path_size(5, path_len));
323                         dpath->path = (char *) &(dpath->parent[5]);
324
325                         dpath->next = NULL;
326                         dpath->len = path_len;
327                         memcpy(dpath->path, ce->name, path_len);
328                         dpath->path[path_len] = '\0';
329                         hashclr(dpath->sha1);
330                         memset(&(dpath->parent[0]), 0,
331                                sizeof(struct combine_diff_parent)*5);
332
333                         if (lstat(ce->name, &st) < 0) {
334                                 if (errno != ENOENT && errno != ENOTDIR) {
335                                         perror(ce->name);
336                                         continue;
337                                 }
338                                 if (silent_on_removed)
339                                         continue;
340                         }
341                         else
342                                 dpath->mode = canon_mode(st.st_mode);
343
344                         while (i < entries) {
345                                 struct cache_entry *nce = active_cache[i];
346                                 int stage;
347
348                                 if (strcmp(ce->name, nce->name))
349                                         break;
350
351                                 /* Stage #2 (ours) is the first parent,
352                                  * stage #3 (theirs) is the second.
353                                  */
354                                 stage = ce_stage(nce);
355                                 if (2 <= stage) {
356                                         int mode = ntohl(nce->ce_mode);
357                                         num_compare_stages++;
358                                         hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
359                                         dpath->parent[stage-2].mode =
360                                                 canon_mode(mode);
361                                         dpath->parent[stage-2].status =
362                                                 DIFF_STATUS_MODIFIED;
363                                 }
364
365                                 /* diff against the proper unmerged stage */
366                                 if (stage == diff_unmerged_stage)
367                                         ce = nce;
368                                 i++;
369                         }
370                         /*
371                          * Compensate for loop update
372                          */
373                         i--;
374
375                         if (revs->combine_merges && num_compare_stages == 2) {
376                                 show_combined_diff(dpath, 2,
377                                                    revs->dense_combined_merges,
378                                                    revs);
379                                 free(dpath);
380                                 continue;
381                         }
382                         free(dpath);
383                         dpath = NULL;
384
385                         /*
386                          * Show the diff for the 'ce' if we found the one
387                          * from the desired stage.
388                          */
389                         diff_unmerge(&revs->diffopt, ce->name, 0, null_sha1);
390                         if (ce_stage(ce) != diff_unmerged_stage)
391                                 continue;
392                 }
393
394                 if (lstat(ce->name, &st) < 0) {
395                         if (errno != ENOENT && errno != ENOTDIR) {
396                                 perror(ce->name);
397                                 continue;
398                         }
399                         if (silent_on_removed)
400                                 continue;
401                         diff_addremove(&revs->diffopt, '-', ntohl(ce->ce_mode),
402                                        ce->sha1, ce->name, NULL);
403                         continue;
404                 }
405                 changed = ce_match_stat(ce, &st, 0);
406                 if (!changed && !revs->diffopt.find_copies_harder)
407                         continue;
408                 oldmode = ntohl(ce->ce_mode);
409
410                 newmode = canon_mode(st.st_mode);
411                 if (!trust_executable_bit &&
412                     S_ISREG(newmode) && S_ISREG(oldmode) &&
413                     ((newmode ^ oldmode) == 0111))
414                         newmode = oldmode;
415                 else if (!has_symlinks &&
416                     S_ISREG(newmode) && S_ISLNK(oldmode))
417                         newmode = oldmode;
418                 diff_change(&revs->diffopt, oldmode, newmode,
419                             ce->sha1, (changed ? null_sha1 : ce->sha1),
420                             ce->name, NULL);
421
422         }
423         diffcore_std(&revs->diffopt);
424         diff_flush(&revs->diffopt);
425         return 0;
426 }
427
428 /*
429  * diff-index
430  */
431
432 /* A file entry went away or appeared */
433 static void diff_index_show_file(struct rev_info *revs,
434                                  const char *prefix,
435                                  struct cache_entry *ce,
436                                  unsigned char *sha1, unsigned int mode)
437 {
438         diff_addremove(&revs->diffopt, prefix[0], ntohl(mode),
439                        sha1, ce->name, NULL);
440 }
441
442 static int get_stat_data(struct cache_entry *ce,
443                          unsigned char **sha1p,
444                          unsigned int *modep,
445                          int cached, int match_missing)
446 {
447         unsigned char *sha1 = ce->sha1;
448         unsigned int mode = ce->ce_mode;
449
450         if (!cached) {
451                 static unsigned char no_sha1[20];
452                 int changed;
453                 struct stat st;
454                 if (lstat(ce->name, &st) < 0) {
455                         if (errno == ENOENT && match_missing) {
456                                 *sha1p = sha1;
457                                 *modep = mode;
458                                 return 0;
459                         }
460                         return -1;
461                 }
462                 changed = ce_match_stat(ce, &st, 0);
463                 if (changed) {
464                         mode = ce_mode_from_stat(ce, st.st_mode);
465                         sha1 = no_sha1;
466                 }
467         }
468
469         *sha1p = sha1;
470         *modep = mode;
471         return 0;
472 }
473
474 static void show_new_file(struct rev_info *revs,
475                           struct cache_entry *new,
476                           int cached, int match_missing)
477 {
478         unsigned char *sha1;
479         unsigned int mode;
480
481         /* New file in the index: it might actually be different in
482          * the working copy.
483          */
484         if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0)
485                 return;
486
487         diff_index_show_file(revs, "+", new, sha1, mode);
488 }
489
490 static int show_modified(struct rev_info *revs,
491                          struct cache_entry *old,
492                          struct cache_entry *new,
493                          int report_missing,
494                          int cached, int match_missing)
495 {
496         unsigned int mode, oldmode;
497         unsigned char *sha1;
498
499         if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0) {
500                 if (report_missing)
501                         diff_index_show_file(revs, "-", old,
502                                              old->sha1, old->ce_mode);
503                 return -1;
504         }
505
506         if (revs->combine_merges && !cached &&
507             (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
508                 struct combine_diff_path *p;
509                 int pathlen = ce_namelen(new);
510
511                 p = xmalloc(combine_diff_path_size(2, pathlen));
512                 p->path = (char *) &p->parent[2];
513                 p->next = NULL;
514                 p->len = pathlen;
515                 memcpy(p->path, new->name, pathlen);
516                 p->path[pathlen] = 0;
517                 p->mode = ntohl(mode);
518                 hashclr(p->sha1);
519                 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
520                 p->parent[0].status = DIFF_STATUS_MODIFIED;
521                 p->parent[0].mode = ntohl(new->ce_mode);
522                 hashcpy(p->parent[0].sha1, new->sha1);
523                 p->parent[1].status = DIFF_STATUS_MODIFIED;
524                 p->parent[1].mode = ntohl(old->ce_mode);
525                 hashcpy(p->parent[1].sha1, old->sha1);
526                 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
527                 free(p);
528                 return 0;
529         }
530
531         oldmode = old->ce_mode;
532         if (mode == oldmode && !hashcmp(sha1, old->sha1) &&
533             !revs->diffopt.find_copies_harder)
534                 return 0;
535
536         mode = ntohl(mode);
537         oldmode = ntohl(oldmode);
538
539         diff_change(&revs->diffopt, oldmode, mode,
540                     old->sha1, sha1, old->name, NULL);
541         return 0;
542 }
543
544 static int diff_cache(struct rev_info *revs,
545                       struct cache_entry **ac, int entries,
546                       const char **pathspec,
547                       int cached, int match_missing)
548 {
549         while (entries) {
550                 struct cache_entry *ce = *ac;
551                 int same = (entries > 1) && ce_same_name(ce, ac[1]);
552
553                 if (!ce_path_match(ce, pathspec))
554                         goto skip_entry;
555
556                 switch (ce_stage(ce)) {
557                 case 0:
558                         /* No stage 1 entry? That means it's a new file */
559                         if (!same) {
560                                 show_new_file(revs, ce, cached, match_missing);
561                                 break;
562                         }
563                         /* Show difference between old and new */
564                         show_modified(revs, ac[1], ce, 1,
565                                       cached, match_missing);
566                         break;
567                 case 1:
568                         /* No stage 3 (merge) entry?
569                          * That means it's been deleted.
570                          */
571                         if (!same) {
572                                 diff_index_show_file(revs, "-", ce,
573                                                      ce->sha1, ce->ce_mode);
574                                 break;
575                         }
576                         /* We come here with ce pointing at stage 1
577                          * (original tree) and ac[1] pointing at stage
578                          * 3 (unmerged).  show-modified with
579                          * report-missing set to false does not say the
580                          * file is deleted but reports true if work
581                          * tree does not have it, in which case we
582                          * fall through to report the unmerged state.
583                          * Otherwise, we show the differences between
584                          * the original tree and the work tree.
585                          */
586                         if (!cached &&
587                             !show_modified(revs, ce, ac[1], 0,
588                                            cached, match_missing))
589                                 break;
590                         diff_unmerge(&revs->diffopt, ce->name,
591                                      ntohl(ce->ce_mode), ce->sha1);
592                         break;
593                 case 3:
594                         diff_unmerge(&revs->diffopt, ce->name,
595                                      0, null_sha1);
596                         break;
597
598                 default:
599                         die("impossible cache entry stage");
600                 }
601
602 skip_entry:
603                 /*
604                  * Ignore all the different stages for this file,
605                  * we've handled the relevant cases now.
606                  */
607                 do {
608                         ac++;
609                         entries--;
610                 } while (entries && ce_same_name(ce, ac[0]));
611         }
612         return 0;
613 }
614
615 /*
616  * This turns all merge entries into "stage 3". That guarantees that
617  * when we read in the new tree (into "stage 1"), we won't lose sight
618  * of the fact that we had unmerged entries.
619  */
620 static void mark_merge_entries(void)
621 {
622         int i;
623         for (i = 0; i < active_nr; i++) {
624                 struct cache_entry *ce = active_cache[i];
625                 if (!ce_stage(ce))
626                         continue;
627                 ce->ce_flags |= htons(CE_STAGEMASK);
628         }
629 }
630
631 int run_diff_index(struct rev_info *revs, int cached)
632 {
633         int ret;
634         struct object *ent;
635         struct tree *tree;
636         const char *tree_name;
637         int match_missing = 0;
638
639         /* 
640          * Backward compatibility wart - "diff-index -m" does
641          * not mean "do not ignore merges", but totally different.
642          */
643         if (!revs->ignore_merges)
644                 match_missing = 1;
645
646         mark_merge_entries();
647
648         ent = revs->pending.objects[0].item;
649         tree_name = revs->pending.objects[0].name;
650         tree = parse_tree_indirect(ent->sha1);
651         if (!tree)
652                 return error("bad tree object %s", tree_name);
653         if (read_tree(tree, 1, revs->prune_data))
654                 return error("unable to read tree object %s", tree_name);
655         ret = diff_cache(revs, active_cache, active_nr, revs->prune_data,
656                          cached, match_missing);
657         diffcore_std(&revs->diffopt);
658         diff_flush(&revs->diffopt);
659         return ret;
660 }
661
662 int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
663 {
664         struct tree *tree;
665         struct rev_info revs;
666         int i;
667         struct cache_entry **dst;
668         struct cache_entry *last = NULL;
669
670         /*
671          * This is used by git-blame to run diff-cache internally;
672          * it potentially needs to repeatedly run this, so we will
673          * start by removing the higher order entries the last round
674          * left behind.
675          */
676         dst = active_cache;
677         for (i = 0; i < active_nr; i++) {
678                 struct cache_entry *ce = active_cache[i];
679                 if (ce_stage(ce)) {
680                         if (last && !strcmp(ce->name, last->name))
681                                 continue;
682                         cache_tree_invalidate_path(active_cache_tree,
683                                                    ce->name);
684                         last = ce;
685                         ce->ce_mode = 0;
686                         ce->ce_flags &= ~htons(CE_STAGEMASK);
687                 }
688                 *dst++ = ce;
689         }
690         active_nr = dst - active_cache;
691
692         init_revisions(&revs, NULL);
693         revs.prune_data = opt->paths;
694         tree = parse_tree_indirect(tree_sha1);
695         if (!tree)
696                 die("bad tree object %s", sha1_to_hex(tree_sha1));
697         if (read_tree(tree, 1, opt->paths))
698                 return error("unable to read tree %s", sha1_to_hex(tree_sha1));
699         return diff_cache(&revs, active_cache, active_nr, revs.prune_data,
700                           1, 0);
701 }