checkout: allow detaching to HEAD even when switching to the tip of a branch
[git/dscho.git] / diff-lib.c
blob5c5b05bfe32bc90484b5bd6a9c171e0f9b04fbd6
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"
14 * diff-files
17 static int read_directory(const char *path, struct path_list *list)
19 DIR *dir;
20 struct dirent *e;
22 if (!(dir = opendir(path)))
23 return error("Could not open directory %s", path);
25 while ((e = readdir(dir)))
26 if (strcmp(".", e->d_name) && strcmp("..", e->d_name))
27 path_list_insert(xstrdup(e->d_name), list);
29 closedir(dir);
30 return 0;
33 static int get_mode(const char *path, int *mode)
35 struct stat st;
37 if (!path || !strcmp(path, "/dev/null"))
38 *mode = 0;
39 else if (!strcmp(path, "-"))
40 *mode = ntohl(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;
48 static int queue_diff(struct diff_options *o,
49 const char *name1, const char *name2)
51 int mode1 = 0, mode2 = 0;
53 if (get_mode(name1, &mode1) || get_mode(name2, &mode2))
54 return -1;
56 if (mode1 && mode2 && S_ISDIR(mode1) != S_ISDIR(mode2))
57 return error("file/directory conflict: %s, %s", name1, name2);
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;
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;
71 if (name1) {
72 len1 = strlen(name1);
73 if (len1 > 0 && name1[len1 - 1] == '/')
74 len1--;
75 memcpy(buffer1, name1, len1);
76 buffer1[len1++] = '/';
79 if (name2) {
80 len2 = strlen(name2);
81 if (len2 > 0 && name2[len2 - 1] == '/')
82 len2--;
83 memcpy(buffer2, name2, len2);
84 buffer2[len2++] = '/';
87 for (i1 = i2 = 0; !ret && (i1 < p1.nr || i2 < p2.nr); ) {
88 const char *n1, *n2;
89 int comp;
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);
99 if (comp > 0)
100 n1 = NULL;
101 else {
102 n1 = buffer1;
103 strncpy(buffer1 + len1, p1.items[i1++].path,
104 PATH_MAX - len1);
107 if (comp < 0)
108 n2 = NULL;
109 else {
110 n2 = buffer2;
111 strncpy(buffer2 + len2, p2.items[i2++].path,
112 PATH_MAX - len2);
115 ret = queue_diff(o, n1, n2);
117 path_list_clear(&p1, 0);
118 path_list_clear(&p2, 0);
120 return ret;
121 } else {
122 struct diff_filespec *d1, *d2;
124 if (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;
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);
140 diff_queue(&diff_queued_diff, d1, d2);
141 return 0;
145 static int is_in_index(const char *path)
147 int len = strlen(path);
148 int pos = cache_name_pos(path, len);
149 char c;
151 if (pos < 0)
152 return 0;
153 if (strncmp(active_cache[pos]->name, path, len))
154 return 0;
155 c = active_cache[pos]->name[len];
156 return c == '\0' || c == '/';
159 static int handle_diff_files_args(struct rev_info *revs,
160 int argc, const char **argv, int *silent)
162 *silent = 0;
164 /* revs->max_count == -2 means --no-index */
165 while (1 < argc && argv[1][0] == '-') {
166 if (!strcmp(argv[1], "--base"))
167 revs->max_count = 1;
168 else if (!strcmp(argv[1], "--ours"))
169 revs->max_count = 2;
170 else if (!strcmp(argv[1], "--theirs"))
171 revs->max_count = 3;
172 else if (!strcmp(argv[1], "-n") ||
173 !strcmp(argv[1], "--no-index")) {
174 revs->max_count = -2;
175 revs->diffopt.exit_with_status = 1;
177 else if (!strcmp(argv[1], "-q"))
178 *silent = 1;
179 else
180 return error("invalid option: %s", argv[1]);
181 argv++; argc--;
184 if (revs->max_count == -1 && revs->diffopt.nr_paths == 2) {
186 * If two files are specified, and at least one is untracked,
187 * default to no-index.
189 read_cache();
190 if (!is_in_index(revs->diffopt.paths[0]) ||
191 !is_in_index(revs->diffopt.paths[1]))
192 revs->max_count = -2;
196 * Make sure there are NO revision (i.e. pending object) parameter,
197 * rev.max_count is reasonable (0 <= n <= 3),
198 * there is no other revision filtering parameters.
200 if (revs->pending.nr || revs->max_count > 3 ||
201 revs->min_age != -1 || revs->max_age != -1)
202 return error("no revision allowed with diff-files");
204 if (revs->max_count == -1 &&
205 (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
206 revs->combine_merges = revs->dense_combined_merges = 1;
208 return 0;
211 static int is_outside_repo(const char *path, int nongit, const char *prefix)
213 int i;
214 if (nongit || !strcmp(path, "-") || path[0] == '/')
215 return 1;
216 if (prefixcmp(path, "../"))
217 return 0;
218 if (!prefix)
219 return 1;
220 for (i = strlen(prefix); !prefixcmp(path, "../"); ) {
221 while (i > 0 && prefix[i - 1] != '/')
222 i--;
223 if (--i < 0)
224 return 1;
225 path += 3;
227 return 0;
230 int setup_diff_no_index(struct rev_info *revs,
231 int argc, const char ** argv, int nongit, const char *prefix)
233 int i;
234 for (i = 1; i < argc; i++)
235 if (argv[i][0] != '-' || argv[i][1] == '\0')
236 break;
237 else if (!strcmp(argv[i], "--")) {
238 i++;
239 break;
240 } else if (i < argc - 3 && !strcmp(argv[i], "--no-index")) {
241 i = argc - 3;
242 revs->diffopt.exit_with_status = 1;
243 break;
245 if (argc != i + 2 || (!is_outside_repo(argv[i + 1], nongit, prefix) &&
246 !is_outside_repo(argv[i], nongit, prefix)))
247 return -1;
249 diff_setup(&revs->diffopt);
250 for (i = 1; i < argc - 2; )
251 if (!strcmp(argv[i], "--no-index"))
252 i++;
253 else {
254 int j = diff_opt_parse(&revs->diffopt,
255 argv + i, argc - i);
256 if (!j)
257 die("invalid diff option/value: %s", argv[i]);
258 i += j;
261 if (prefix) {
262 int len = strlen(prefix);
264 revs->diffopt.paths = xcalloc(2, sizeof(char*));
265 for (i = 0; i < 2; i++) {
266 const char *p = argv[argc - 2 + i];
268 * stdin should be spelled as '-'; if you have
269 * path that is '-', spell it as ./-.
271 p = (strcmp(p, "-")
272 ? xstrdup(prefix_filename(prefix, len, p))
273 : p);
274 revs->diffopt.paths[i] = p;
277 else
278 revs->diffopt.paths = argv + argc - 2;
279 revs->diffopt.nr_paths = 2;
280 revs->max_count = -2;
281 return 0;
284 int run_diff_files_cmd(struct rev_info *revs, int argc, const char **argv)
286 int silent_on_removed;
288 if (handle_diff_files_args(revs, argc, argv, &silent_on_removed))
289 return -1;
291 if (revs->max_count == -2) {
292 if (revs->diffopt.nr_paths != 2)
293 return error("need two files/directories with --no-index");
294 if (queue_diff(&revs->diffopt, revs->diffopt.paths[0],
295 revs->diffopt.paths[1]))
296 return -1;
297 diffcore_std(&revs->diffopt);
298 diff_flush(&revs->diffopt);
300 * The return code for --no-index imitates diff(1):
301 * 0 = no changes, 1 = changes, else error
303 return revs->diffopt.found_changes;
306 if (read_cache() < 0) {
307 perror("read_cache");
308 return -1;
310 return run_diff_files(revs, silent_on_removed);
313 int run_diff_files(struct rev_info *revs, int silent_on_removed)
315 int entries, i;
316 int diff_unmerged_stage = revs->max_count;
318 if (diff_unmerged_stage < 0)
319 diff_unmerged_stage = 2;
320 entries = active_nr;
321 for (i = 0; i < entries; i++) {
322 struct stat st;
323 unsigned int oldmode, newmode;
324 struct cache_entry *ce = active_cache[i];
325 int changed;
327 if (revs->diffopt.quiet && revs->diffopt.has_changes)
328 break;
330 if (!ce_path_match(ce, revs->prune_data))
331 continue;
333 if (ce_stage(ce)) {
334 struct combine_diff_path *dpath;
335 int num_compare_stages = 0;
336 size_t path_len;
338 path_len = ce_namelen(ce);
340 dpath = xmalloc(combine_diff_path_size(5, path_len));
341 dpath->path = (char *) &(dpath->parent[5]);
343 dpath->next = NULL;
344 dpath->len = path_len;
345 memcpy(dpath->path, ce->name, path_len);
346 dpath->path[path_len] = '\0';
347 hashclr(dpath->sha1);
348 memset(&(dpath->parent[0]), 0,
349 sizeof(struct combine_diff_parent)*5);
351 if (lstat(ce->name, &st) < 0) {
352 if (errno != ENOENT && errno != ENOTDIR) {
353 perror(ce->name);
354 continue;
356 if (silent_on_removed)
357 continue;
359 else
360 dpath->mode = canon_mode(st.st_mode);
362 while (i < entries) {
363 struct cache_entry *nce = active_cache[i];
364 int stage;
366 if (strcmp(ce->name, nce->name))
367 break;
369 /* Stage #2 (ours) is the first parent,
370 * stage #3 (theirs) is the second.
372 stage = ce_stage(nce);
373 if (2 <= stage) {
374 int mode = ntohl(nce->ce_mode);
375 num_compare_stages++;
376 hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
377 dpath->parent[stage-2].mode =
378 canon_mode(mode);
379 dpath->parent[stage-2].status =
380 DIFF_STATUS_MODIFIED;
383 /* diff against the proper unmerged stage */
384 if (stage == diff_unmerged_stage)
385 ce = nce;
386 i++;
389 * Compensate for loop update
391 i--;
393 if (revs->combine_merges && num_compare_stages == 2) {
394 show_combined_diff(dpath, 2,
395 revs->dense_combined_merges,
396 revs);
397 free(dpath);
398 continue;
400 free(dpath);
401 dpath = NULL;
404 * Show the diff for the 'ce' if we found the one
405 * from the desired stage.
407 diff_unmerge(&revs->diffopt, ce->name, 0, null_sha1);
408 if (ce_stage(ce) != diff_unmerged_stage)
409 continue;
412 if (lstat(ce->name, &st) < 0) {
413 if (errno != ENOENT && errno != ENOTDIR) {
414 perror(ce->name);
415 continue;
417 if (silent_on_removed)
418 continue;
419 diff_addremove(&revs->diffopt, '-', ntohl(ce->ce_mode),
420 ce->sha1, ce->name, NULL);
421 continue;
423 changed = ce_match_stat(ce, &st, 0);
424 if (!changed && !revs->diffopt.find_copies_harder)
425 continue;
426 oldmode = ntohl(ce->ce_mode);
428 newmode = canon_mode(st.st_mode);
429 if (!trust_executable_bit &&
430 S_ISREG(newmode) && S_ISREG(oldmode) &&
431 ((newmode ^ oldmode) == 0111))
432 newmode = oldmode;
433 else if (!has_symlinks &&
434 S_ISREG(newmode) && S_ISLNK(oldmode))
435 newmode = oldmode;
436 diff_change(&revs->diffopt, oldmode, newmode,
437 ce->sha1, (changed ? null_sha1 : ce->sha1),
438 ce->name, NULL);
441 diffcore_std(&revs->diffopt);
442 diff_flush(&revs->diffopt);
443 return 0;
447 * diff-index
450 /* A file entry went away or appeared */
451 static void diff_index_show_file(struct rev_info *revs,
452 const char *prefix,
453 struct cache_entry *ce,
454 unsigned char *sha1, unsigned int mode)
456 diff_addremove(&revs->diffopt, prefix[0], ntohl(mode),
457 sha1, ce->name, NULL);
460 static int get_stat_data(struct cache_entry *ce,
461 unsigned char **sha1p,
462 unsigned int *modep,
463 int cached, int match_missing)
465 unsigned char *sha1 = ce->sha1;
466 unsigned int mode = ce->ce_mode;
468 if (!cached) {
469 static unsigned char no_sha1[20];
470 int changed;
471 struct stat st;
472 if (lstat(ce->name, &st) < 0) {
473 if (errno == ENOENT && match_missing) {
474 *sha1p = sha1;
475 *modep = mode;
476 return 0;
478 return -1;
480 changed = ce_match_stat(ce, &st, 0);
481 if (changed) {
482 mode = ce_mode_from_stat(ce, st.st_mode);
483 sha1 = no_sha1;
487 *sha1p = sha1;
488 *modep = mode;
489 return 0;
492 static void show_new_file(struct rev_info *revs,
493 struct cache_entry *new,
494 int cached, int match_missing)
496 unsigned char *sha1;
497 unsigned int mode;
499 /* New file in the index: it might actually be different in
500 * the working copy.
502 if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0)
503 return;
505 diff_index_show_file(revs, "+", new, sha1, mode);
508 static int show_modified(struct rev_info *revs,
509 struct cache_entry *old,
510 struct cache_entry *new,
511 int report_missing,
512 int cached, int match_missing)
514 unsigned int mode, oldmode;
515 unsigned char *sha1;
517 if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0) {
518 if (report_missing)
519 diff_index_show_file(revs, "-", old,
520 old->sha1, old->ce_mode);
521 return -1;
524 if (revs->combine_merges && !cached &&
525 (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
526 struct combine_diff_path *p;
527 int pathlen = ce_namelen(new);
529 p = xmalloc(combine_diff_path_size(2, pathlen));
530 p->path = (char *) &p->parent[2];
531 p->next = NULL;
532 p->len = pathlen;
533 memcpy(p->path, new->name, pathlen);
534 p->path[pathlen] = 0;
535 p->mode = ntohl(mode);
536 hashclr(p->sha1);
537 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
538 p->parent[0].status = DIFF_STATUS_MODIFIED;
539 p->parent[0].mode = ntohl(new->ce_mode);
540 hashcpy(p->parent[0].sha1, new->sha1);
541 p->parent[1].status = DIFF_STATUS_MODIFIED;
542 p->parent[1].mode = ntohl(old->ce_mode);
543 hashcpy(p->parent[1].sha1, old->sha1);
544 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
545 free(p);
546 return 0;
549 oldmode = old->ce_mode;
550 if (mode == oldmode && !hashcmp(sha1, old->sha1) &&
551 !revs->diffopt.find_copies_harder)
552 return 0;
554 mode = ntohl(mode);
555 oldmode = ntohl(oldmode);
557 diff_change(&revs->diffopt, oldmode, mode,
558 old->sha1, sha1, old->name, NULL);
559 return 0;
562 static int diff_cache(struct rev_info *revs,
563 struct cache_entry **ac, int entries,
564 const char **pathspec,
565 int cached, int match_missing)
567 while (entries) {
568 struct cache_entry *ce = *ac;
569 int same = (entries > 1) && ce_same_name(ce, ac[1]);
571 if (revs->diffopt.quiet && revs->diffopt.has_changes)
572 break;
574 if (!ce_path_match(ce, pathspec))
575 goto skip_entry;
577 switch (ce_stage(ce)) {
578 case 0:
579 /* No stage 1 entry? That means it's a new file */
580 if (!same) {
581 show_new_file(revs, ce, cached, match_missing);
582 break;
584 /* Show difference between old and new */
585 show_modified(revs, ac[1], ce, 1,
586 cached, match_missing);
587 break;
588 case 1:
589 /* No stage 3 (merge) entry?
590 * That means it's been deleted.
592 if (!same) {
593 diff_index_show_file(revs, "-", ce,
594 ce->sha1, ce->ce_mode);
595 break;
597 /* We come here with ce pointing at stage 1
598 * (original tree) and ac[1] pointing at stage
599 * 3 (unmerged). show-modified with
600 * report-missing set to false does not say the
601 * file is deleted but reports true if work
602 * tree does not have it, in which case we
603 * fall through to report the unmerged state.
604 * Otherwise, we show the differences between
605 * the original tree and the work tree.
607 if (!cached &&
608 !show_modified(revs, ce, ac[1], 0,
609 cached, match_missing))
610 break;
611 diff_unmerge(&revs->diffopt, ce->name,
612 ntohl(ce->ce_mode), ce->sha1);
613 break;
614 case 3:
615 diff_unmerge(&revs->diffopt, ce->name,
616 0, null_sha1);
617 break;
619 default:
620 die("impossible cache entry stage");
623 skip_entry:
625 * Ignore all the different stages for this file,
626 * we've handled the relevant cases now.
628 do {
629 ac++;
630 entries--;
631 } while (entries && ce_same_name(ce, ac[0]));
633 return 0;
637 * This turns all merge entries into "stage 3". That guarantees that
638 * when we read in the new tree (into "stage 1"), we won't lose sight
639 * of the fact that we had unmerged entries.
641 static void mark_merge_entries(void)
643 int i;
644 for (i = 0; i < active_nr; i++) {
645 struct cache_entry *ce = active_cache[i];
646 if (!ce_stage(ce))
647 continue;
648 ce->ce_flags |= htons(CE_STAGEMASK);
652 int run_diff_index(struct rev_info *revs, int cached)
654 int ret;
655 struct object *ent;
656 struct tree *tree;
657 const char *tree_name;
658 int match_missing = 0;
661 * Backward compatibility wart - "diff-index -m" does
662 * not mean "do not ignore merges", but totally different.
664 if (!revs->ignore_merges)
665 match_missing = 1;
667 mark_merge_entries();
669 ent = revs->pending.objects[0].item;
670 tree_name = revs->pending.objects[0].name;
671 tree = parse_tree_indirect(ent->sha1);
672 if (!tree)
673 return error("bad tree object %s", tree_name);
674 if (read_tree(tree, 1, revs->prune_data))
675 return error("unable to read tree object %s", tree_name);
676 ret = diff_cache(revs, active_cache, active_nr, revs->prune_data,
677 cached, match_missing);
678 diffcore_std(&revs->diffopt);
679 diff_flush(&revs->diffopt);
680 return ret;
683 int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
685 struct tree *tree;
686 struct rev_info revs;
687 int i;
688 struct cache_entry **dst;
689 struct cache_entry *last = NULL;
692 * This is used by git-blame to run diff-cache internally;
693 * it potentially needs to repeatedly run this, so we will
694 * start by removing the higher order entries the last round
695 * left behind.
697 dst = active_cache;
698 for (i = 0; i < active_nr; i++) {
699 struct cache_entry *ce = active_cache[i];
700 if (ce_stage(ce)) {
701 if (last && !strcmp(ce->name, last->name))
702 continue;
703 cache_tree_invalidate_path(active_cache_tree,
704 ce->name);
705 last = ce;
706 ce->ce_mode = 0;
707 ce->ce_flags &= ~htons(CE_STAGEMASK);
709 *dst++ = ce;
711 active_nr = dst - active_cache;
713 init_revisions(&revs, NULL);
714 revs.prune_data = opt->paths;
715 tree = parse_tree_indirect(tree_sha1);
716 if (!tree)
717 die("bad tree object %s", sha1_to_hex(tree_sha1));
718 if (read_tree(tree, 1, opt->paths))
719 return error("unable to read tree %s", sha1_to_hex(tree_sha1));
720 return diff_cache(&revs, active_cache, active_nr, revs.prune_data,
721 1, 0);