Make on-disk index representation separate from in-core one
[git/git.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(e->d_name, list);
28
29 closedir(dir);
30 return 0;
31 }
32
33 static int get_mode(const char *path, int *mode)
34 {
35 struct stat st;
36
37 if (!path || !strcmp(path, "/dev/null"))
38 *mode = 0;
39 else if (!strcmp(path, "-"))
40 *mode = create_ce_mode(0666);
41 else if (stat(path, &st))
42 return error("Could not access '%s'", path);
43 else
44 *mode = st.st_mode;
45 return 0;
46 }
47
48 static int queue_diff(struct diff_options *o,
49 const char *name1, const char *name2)
50 {
51 int mode1 = 0, mode2 = 0;
52
53 if (get_mode(name1, &mode1) || get_mode(name2, &mode2))
54 return -1;
55
56 if (mode1 && mode2 && S_ISDIR(mode1) != S_ISDIR(mode2))
57 return error("file/directory conflict: %s, %s", name1, name2);
58
59 if (S_ISDIR(mode1) || S_ISDIR(mode2)) {
60 char buffer1[PATH_MAX], buffer2[PATH_MAX];
61 struct path_list p1 = {NULL, 0, 0, 1}, p2 = {NULL, 0, 0, 1};
62 int len1 = 0, len2 = 0, i1, i2, ret = 0;
63
64 if (name1 && read_directory(name1, &p1))
65 return -1;
66 if (name2 && read_directory(name2, &p2)) {
67 path_list_clear(&p1, 0);
68 return -1;
69 }
70
71 if (name1) {
72 len1 = strlen(name1);
73 if (len1 > 0 && name1[len1 - 1] == '/')
74 len1--;
75 memcpy(buffer1, name1, len1);
76 buffer1[len1++] = '/';
77 }
78
79 if (name2) {
80 len2 = strlen(name2);
81 if (len2 > 0 && name2[len2 - 1] == '/')
82 len2--;
83 memcpy(buffer2, name2, len2);
84 buffer2[len2++] = '/';
85 }
86
87 for (i1 = i2 = 0; !ret && (i1 < p1.nr || i2 < p2.nr); ) {
88 const char *n1, *n2;
89 int comp;
90
91 if (i1 == p1.nr)
92 comp = 1;
93 else if (i2 == p2.nr)
94 comp = -1;
95 else
96 comp = strcmp(p1.items[i1].path,
97 p2.items[i2].path);
98
99 if (comp > 0)
100 n1 = NULL;
101 else {
102 n1 = buffer1;
103 strncpy(buffer1 + len1, p1.items[i1++].path,
104 PATH_MAX - len1);
105 }
106
107 if (comp < 0)
108 n2 = NULL;
109 else {
110 n2 = buffer2;
111 strncpy(buffer2 + len2, p2.items[i2++].path,
112 PATH_MAX - len2);
113 }
114
115 ret = queue_diff(o, n1, n2);
116 }
117 path_list_clear(&p1, 0);
118 path_list_clear(&p2, 0);
119
120 return ret;
121 } else {
122 struct diff_filespec *d1, *d2;
123
124 if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
125 unsigned tmp;
126 const char *tmp_c;
127 tmp = mode1; mode1 = mode2; mode2 = tmp;
128 tmp_c = name1; name1 = name2; name2 = tmp_c;
129 }
130
131 if (!name1)
132 name1 = "/dev/null";
133 if (!name2)
134 name2 = "/dev/null";
135 d1 = alloc_filespec(name1);
136 d2 = alloc_filespec(name2);
137 fill_filespec(d1, null_sha1, mode1);
138 fill_filespec(d2, null_sha1, mode2);
139
140 diff_queue(&diff_queued_diff, d1, d2);
141 return 0;
142 }
143 }
144
145 /*
146 * Does the path name a blob in the working tree, or a directory
147 * in the working tree?
148 */
149 static int is_in_index(const char *path)
150 {
151 int len, pos;
152 struct cache_entry *ce;
153
154 len = strlen(path);
155 while (path[len-1] == '/')
156 len--;
157 if (!len)
158 return 1; /* "." */
159 pos = cache_name_pos(path, len);
160 if (0 <= pos)
161 return 1;
162 pos = -1 - pos;
163 while (pos < active_nr) {
164 ce = active_cache[pos++];
165 if (ce_namelen(ce) <= len ||
166 strncmp(ce->name, path, len) ||
167 (ce->name[len] > '/'))
168 break; /* path cannot be a prefix */
169 if (ce->name[len] == '/')
170 return 1;
171 }
172 return 0;
173 }
174
175 static int handle_diff_files_args(struct rev_info *revs,
176 int argc, const char **argv,
177 unsigned int *options)
178 {
179 *options = 0;
180
181 /* revs->max_count == -2 means --no-index */
182 while (1 < argc && argv[1][0] == '-') {
183 if (!strcmp(argv[1], "--base"))
184 revs->max_count = 1;
185 else if (!strcmp(argv[1], "--ours"))
186 revs->max_count = 2;
187 else if (!strcmp(argv[1], "--theirs"))
188 revs->max_count = 3;
189 else if (!strcmp(argv[1], "-n") ||
190 !strcmp(argv[1], "--no-index")) {
191 revs->max_count = -2;
192 DIFF_OPT_SET(&revs->diffopt, EXIT_WITH_STATUS);
193 DIFF_OPT_SET(&revs->diffopt, NO_INDEX);
194 }
195 else if (!strcmp(argv[1], "-q"))
196 *options |= DIFF_SILENT_ON_REMOVED;
197 else
198 return error("invalid option: %s", argv[1]);
199 argv++; argc--;
200 }
201
202 if (revs->max_count == -1 && revs->diffopt.nr_paths == 2) {
203 /*
204 * If two files are specified, and at least one is untracked,
205 * default to no-index.
206 */
207 read_cache();
208 if (!is_in_index(revs->diffopt.paths[0]) ||
209 !is_in_index(revs->diffopt.paths[1])) {
210 revs->max_count = -2;
211 DIFF_OPT_SET(&revs->diffopt, NO_INDEX);
212 }
213 }
214
215 /*
216 * Make sure there are NO revision (i.e. pending object) parameter,
217 * rev.max_count is reasonable (0 <= n <= 3),
218 * there is no other revision filtering parameters.
219 */
220 if (revs->pending.nr || revs->max_count > 3 ||
221 revs->min_age != -1 || revs->max_age != -1)
222 return error("no revision allowed with diff-files");
223
224 if (revs->max_count == -1 &&
225 (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
226 revs->combine_merges = revs->dense_combined_merges = 1;
227
228 return 0;
229 }
230
231 static int is_outside_repo(const char *path, int nongit, const char *prefix)
232 {
233 int i;
234 if (nongit || !strcmp(path, "-") || is_absolute_path(path))
235 return 1;
236 if (prefixcmp(path, "../"))
237 return 0;
238 if (!prefix)
239 return 1;
240 for (i = strlen(prefix); !prefixcmp(path, "../"); ) {
241 while (i > 0 && prefix[i - 1] != '/')
242 i--;
243 if (--i < 0)
244 return 1;
245 path += 3;
246 }
247 return 0;
248 }
249
250 int setup_diff_no_index(struct rev_info *revs,
251 int argc, const char ** argv, int nongit, const char *prefix)
252 {
253 int i;
254 for (i = 1; i < argc; i++)
255 if (argv[i][0] != '-' || argv[i][1] == '\0')
256 break;
257 else if (!strcmp(argv[i], "--")) {
258 i++;
259 break;
260 } else if (i < argc - 3 && !strcmp(argv[i], "--no-index")) {
261 i = argc - 3;
262 DIFF_OPT_SET(&revs->diffopt, EXIT_WITH_STATUS);
263 break;
264 }
265 if (argc != i + 2 || (!is_outside_repo(argv[i + 1], nongit, prefix) &&
266 !is_outside_repo(argv[i], nongit, prefix)))
267 return -1;
268
269 diff_setup(&revs->diffopt);
270 for (i = 1; i < argc - 2; )
271 if (!strcmp(argv[i], "--no-index"))
272 i++;
273 else {
274 int j = diff_opt_parse(&revs->diffopt,
275 argv + i, argc - i);
276 if (!j)
277 die("invalid diff option/value: %s", argv[i]);
278 i += j;
279 }
280
281 if (prefix) {
282 int len = strlen(prefix);
283
284 revs->diffopt.paths = xcalloc(2, sizeof(char*));
285 for (i = 0; i < 2; i++) {
286 const char *p = argv[argc - 2 + i];
287 /*
288 * stdin should be spelled as '-'; if you have
289 * path that is '-', spell it as ./-.
290 */
291 p = (strcmp(p, "-")
292 ? xstrdup(prefix_filename(prefix, len, p))
293 : p);
294 revs->diffopt.paths[i] = p;
295 }
296 }
297 else
298 revs->diffopt.paths = argv + argc - 2;
299 revs->diffopt.nr_paths = 2;
300 DIFF_OPT_SET(&revs->diffopt, NO_INDEX);
301 revs->max_count = -2;
302 if (diff_setup_done(&revs->diffopt) < 0)
303 die("diff_setup_done failed");
304 return 0;
305 }
306
307 int run_diff_files_cmd(struct rev_info *revs, int argc, const char **argv)
308 {
309 unsigned int options;
310
311 if (handle_diff_files_args(revs, argc, argv, &options))
312 return -1;
313
314 if (DIFF_OPT_TST(&revs->diffopt, NO_INDEX)) {
315 if (revs->diffopt.nr_paths != 2)
316 return error("need two files/directories with --no-index");
317 if (queue_diff(&revs->diffopt, revs->diffopt.paths[0],
318 revs->diffopt.paths[1]))
319 return -1;
320 diffcore_std(&revs->diffopt);
321 diff_flush(&revs->diffopt);
322 /*
323 * The return code for --no-index imitates diff(1):
324 * 0 = no changes, 1 = changes, else error
325 */
326 return revs->diffopt.found_changes;
327 }
328
329 if (read_cache() < 0) {
330 perror("read_cache");
331 return -1;
332 }
333 return run_diff_files(revs, options);
334 }
335
336 int run_diff_files(struct rev_info *revs, unsigned int option)
337 {
338 int entries, i;
339 int diff_unmerged_stage = revs->max_count;
340 int silent_on_removed = option & DIFF_SILENT_ON_REMOVED;
341 unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
342 ? CE_MATCH_RACY_IS_DIRTY : 0);
343
344 if (diff_unmerged_stage < 0)
345 diff_unmerged_stage = 2;
346 entries = active_nr;
347 for (i = 0; i < entries; i++) {
348 struct stat st;
349 unsigned int oldmode, newmode;
350 struct cache_entry *ce = active_cache[i];
351 int changed;
352
353 if (DIFF_OPT_TST(&revs->diffopt, QUIET) &&
354 DIFF_OPT_TST(&revs->diffopt, HAS_CHANGES))
355 break;
356
357 if (!ce_path_match(ce, revs->prune_data))
358 continue;
359
360 if (ce_stage(ce)) {
361 struct combine_diff_path *dpath;
362 int num_compare_stages = 0;
363 size_t path_len;
364
365 path_len = ce_namelen(ce);
366
367 dpath = xmalloc(combine_diff_path_size(5, path_len));
368 dpath->path = (char *) &(dpath->parent[5]);
369
370 dpath->next = NULL;
371 dpath->len = path_len;
372 memcpy(dpath->path, ce->name, path_len);
373 dpath->path[path_len] = '\0';
374 hashclr(dpath->sha1);
375 memset(&(dpath->parent[0]), 0,
376 sizeof(struct combine_diff_parent)*5);
377
378 if (lstat(ce->name, &st) < 0) {
379 if (errno != ENOENT && errno != ENOTDIR) {
380 perror(ce->name);
381 continue;
382 }
383 if (silent_on_removed)
384 continue;
385 }
386 else
387 dpath->mode = ce_mode_from_stat(ce, st.st_mode);
388
389 while (i < entries) {
390 struct cache_entry *nce = active_cache[i];
391 int stage;
392
393 if (strcmp(ce->name, nce->name))
394 break;
395
396 /* Stage #2 (ours) is the first parent,
397 * stage #3 (theirs) is the second.
398 */
399 stage = ce_stage(nce);
400 if (2 <= stage) {
401 int mode = nce->ce_mode;
402 num_compare_stages++;
403 hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
404 dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
405 dpath->parent[stage-2].status =
406 DIFF_STATUS_MODIFIED;
407 }
408
409 /* diff against the proper unmerged stage */
410 if (stage == diff_unmerged_stage)
411 ce = nce;
412 i++;
413 }
414 /*
415 * Compensate for loop update
416 */
417 i--;
418
419 if (revs->combine_merges && num_compare_stages == 2) {
420 show_combined_diff(dpath, 2,
421 revs->dense_combined_merges,
422 revs);
423 free(dpath);
424 continue;
425 }
426 free(dpath);
427 dpath = NULL;
428
429 /*
430 * Show the diff for the 'ce' if we found the one
431 * from the desired stage.
432 */
433 diff_unmerge(&revs->diffopt, ce->name, 0, null_sha1);
434 if (ce_stage(ce) != diff_unmerged_stage)
435 continue;
436 }
437
438 if (lstat(ce->name, &st) < 0) {
439 if (errno != ENOENT && errno != ENOTDIR) {
440 perror(ce->name);
441 continue;
442 }
443 if (silent_on_removed)
444 continue;
445 diff_addremove(&revs->diffopt, '-', ce->ce_mode,
446 ce->sha1, ce->name, NULL);
447 continue;
448 }
449 changed = ce_match_stat(ce, &st, ce_option);
450 if (!changed && !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
451 continue;
452 oldmode = ce->ce_mode;
453 newmode = ce_mode_from_stat(ce, st.st_mode);
454 diff_change(&revs->diffopt, oldmode, newmode,
455 ce->sha1, (changed ? null_sha1 : ce->sha1),
456 ce->name, NULL);
457
458 }
459 diffcore_std(&revs->diffopt);
460 diff_flush(&revs->diffopt);
461 return 0;
462 }
463
464 /*
465 * diff-index
466 */
467
468 /* A file entry went away or appeared */
469 static void diff_index_show_file(struct rev_info *revs,
470 const char *prefix,
471 struct cache_entry *ce,
472 unsigned char *sha1, unsigned int mode)
473 {
474 diff_addremove(&revs->diffopt, prefix[0], mode,
475 sha1, ce->name, NULL);
476 }
477
478 static int get_stat_data(struct cache_entry *ce,
479 unsigned char **sha1p,
480 unsigned int *modep,
481 int cached, int match_missing)
482 {
483 unsigned char *sha1 = ce->sha1;
484 unsigned int mode = ce->ce_mode;
485
486 if (!cached) {
487 static unsigned char no_sha1[20];
488 int changed;
489 struct stat st;
490 if (lstat(ce->name, &st) < 0) {
491 if (errno == ENOENT && match_missing) {
492 *sha1p = sha1;
493 *modep = mode;
494 return 0;
495 }
496 return -1;
497 }
498 changed = ce_match_stat(ce, &st, 0);
499 if (changed) {
500 mode = ce_mode_from_stat(ce, st.st_mode);
501 sha1 = no_sha1;
502 }
503 }
504
505 *sha1p = sha1;
506 *modep = mode;
507 return 0;
508 }
509
510 static void show_new_file(struct rev_info *revs,
511 struct cache_entry *new,
512 int cached, int match_missing)
513 {
514 unsigned char *sha1;
515 unsigned int mode;
516
517 /* New file in the index: it might actually be different in
518 * the working copy.
519 */
520 if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0)
521 return;
522
523 diff_index_show_file(revs, "+", new, sha1, mode);
524 }
525
526 static int show_modified(struct rev_info *revs,
527 struct cache_entry *old,
528 struct cache_entry *new,
529 int report_missing,
530 int cached, int match_missing)
531 {
532 unsigned int mode, oldmode;
533 unsigned char *sha1;
534
535 if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0) {
536 if (report_missing)
537 diff_index_show_file(revs, "-", old,
538 old->sha1, old->ce_mode);
539 return -1;
540 }
541
542 if (revs->combine_merges && !cached &&
543 (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
544 struct combine_diff_path *p;
545 int pathlen = ce_namelen(new);
546
547 p = xmalloc(combine_diff_path_size(2, pathlen));
548 p->path = (char *) &p->parent[2];
549 p->next = NULL;
550 p->len = pathlen;
551 memcpy(p->path, new->name, pathlen);
552 p->path[pathlen] = 0;
553 p->mode = mode;
554 hashclr(p->sha1);
555 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
556 p->parent[0].status = DIFF_STATUS_MODIFIED;
557 p->parent[0].mode = new->ce_mode;
558 hashcpy(p->parent[0].sha1, new->sha1);
559 p->parent[1].status = DIFF_STATUS_MODIFIED;
560 p->parent[1].mode = old->ce_mode;
561 hashcpy(p->parent[1].sha1, old->sha1);
562 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
563 free(p);
564 return 0;
565 }
566
567 oldmode = old->ce_mode;
568 if (mode == oldmode && !hashcmp(sha1, old->sha1) &&
569 !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
570 return 0;
571
572 diff_change(&revs->diffopt, oldmode, mode,
573 old->sha1, sha1, old->name, NULL);
574 return 0;
575 }
576
577 static int diff_cache(struct rev_info *revs,
578 struct cache_entry **ac, int entries,
579 const char **pathspec,
580 int cached, int match_missing)
581 {
582 while (entries) {
583 struct cache_entry *ce = *ac;
584 int same = (entries > 1) && ce_same_name(ce, ac[1]);
585
586 if (DIFF_OPT_TST(&revs->diffopt, QUIET) &&
587 DIFF_OPT_TST(&revs->diffopt, HAS_CHANGES))
588 break;
589
590 if (!ce_path_match(ce, pathspec))
591 goto skip_entry;
592
593 switch (ce_stage(ce)) {
594 case 0:
595 /* No stage 1 entry? That means it's a new file */
596 if (!same) {
597 show_new_file(revs, ce, cached, match_missing);
598 break;
599 }
600 /* Show difference between old and new */
601 show_modified(revs, ac[1], ce, 1,
602 cached, match_missing);
603 break;
604 case 1:
605 /* No stage 3 (merge) entry?
606 * That means it's been deleted.
607 */
608 if (!same) {
609 diff_index_show_file(revs, "-", ce,
610 ce->sha1, ce->ce_mode);
611 break;
612 }
613 /* We come here with ce pointing at stage 1
614 * (original tree) and ac[1] pointing at stage
615 * 3 (unmerged). show-modified with
616 * report-missing set to false does not say the
617 * file is deleted but reports true if work
618 * tree does not have it, in which case we
619 * fall through to report the unmerged state.
620 * Otherwise, we show the differences between
621 * the original tree and the work tree.
622 */
623 if (!cached &&
624 !show_modified(revs, ce, ac[1], 0,
625 cached, match_missing))
626 break;
627 diff_unmerge(&revs->diffopt, ce->name,
628 ce->ce_mode, ce->sha1);
629 break;
630 case 3:
631 diff_unmerge(&revs->diffopt, ce->name,
632 0, null_sha1);
633 break;
634
635 default:
636 die("impossible cache entry stage");
637 }
638
639 skip_entry:
640 /*
641 * Ignore all the different stages for this file,
642 * we've handled the relevant cases now.
643 */
644 do {
645 ac++;
646 entries--;
647 } while (entries && ce_same_name(ce, ac[0]));
648 }
649 return 0;
650 }
651
652 /*
653 * This turns all merge entries into "stage 3". That guarantees that
654 * when we read in the new tree (into "stage 1"), we won't lose sight
655 * of the fact that we had unmerged entries.
656 */
657 static void mark_merge_entries(void)
658 {
659 int i;
660 for (i = 0; i < active_nr; i++) {
661 struct cache_entry *ce = active_cache[i];
662 if (!ce_stage(ce))
663 continue;
664 ce->ce_flags |= CE_STAGEMASK;
665 }
666 }
667
668 int run_diff_index(struct rev_info *revs, int cached)
669 {
670 int ret;
671 struct object *ent;
672 struct tree *tree;
673 const char *tree_name;
674 int match_missing = 0;
675
676 /*
677 * Backward compatibility wart - "diff-index -m" does
678 * not mean "do not ignore merges", but totally different.
679 */
680 if (!revs->ignore_merges)
681 match_missing = 1;
682
683 mark_merge_entries();
684
685 ent = revs->pending.objects[0].item;
686 tree_name = revs->pending.objects[0].name;
687 tree = parse_tree_indirect(ent->sha1);
688 if (!tree)
689 return error("bad tree object %s", tree_name);
690 if (read_tree(tree, 1, revs->prune_data))
691 return error("unable to read tree object %s", tree_name);
692 ret = diff_cache(revs, active_cache, active_nr, revs->prune_data,
693 cached, match_missing);
694 diffcore_std(&revs->diffopt);
695 diff_flush(&revs->diffopt);
696 return ret;
697 }
698
699 int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
700 {
701 struct tree *tree;
702 struct rev_info revs;
703 int i;
704 struct cache_entry **dst;
705 struct cache_entry *last = NULL;
706
707 /*
708 * This is used by git-blame to run diff-cache internally;
709 * it potentially needs to repeatedly run this, so we will
710 * start by removing the higher order entries the last round
711 * left behind.
712 */
713 dst = active_cache;
714 for (i = 0; i < active_nr; i++) {
715 struct cache_entry *ce = active_cache[i];
716 if (ce_stage(ce)) {
717 if (last && !strcmp(ce->name, last->name))
718 continue;
719 cache_tree_invalidate_path(active_cache_tree,
720 ce->name);
721 last = ce;
722 ce->ce_flags |= CE_REMOVE;
723 }
724 *dst++ = ce;
725 }
726 active_nr = dst - active_cache;
727
728 init_revisions(&revs, NULL);
729 revs.prune_data = opt->paths;
730 tree = parse_tree_indirect(tree_sha1);
731 if (!tree)
732 die("bad tree object %s", sha1_to_hex(tree_sha1));
733 if (read_tree(tree, 1, opt->paths))
734 return error("unable to read tree %s", sha1_to_hex(tree_sha1));
735 return diff_cache(&revs, active_cache, active_nr, revs.prune_data,
736 1, 0);
737 }