1#include "cache.h"
2#include "dir.h"
3#include "tree.h"
4#include "tree-walk.h"
5#include "cache-tree.h"
6#include "unpack-trees.h"
7#define DBRT_DEBUG 1
9struct tree_entry_list {
11 struct tree_entry_list *next;
12 unsigned directory : 1;
13 unsigned executable : 1;
14 unsigned symlink : 1;
15 unsigned int mode;
16 const char *name;
17 const unsigned char *sha1;
18};
19static struct tree_entry_list *create_tree_entry_list(struct tree *tree)
21{
22 struct tree_desc desc;
23 struct name_entry one;
24 struct tree_entry_list *ret = NULL;
25 struct tree_entry_list **list_p = &ret;
26 if (!tree->object.parsed)
28 parse_tree(tree);
29 init_tree_desc(&desc, tree->buffer, tree->size);
31 while (tree_entry(&desc, &one)) {
33 struct tree_entry_list *entry;
34 entry = xmalloc(sizeof(struct tree_entry_list));
36 entry->name = one.path;
37 entry->sha1 = one.sha1;
38 entry->mode = one.mode;
39 entry->directory = S_ISDIR(one.mode) != 0;
40 entry->executable = (one.mode & S_IXUSR) != 0;
41 entry->symlink = S_ISLNK(one.mode) != 0;
42 entry->next = NULL;
43 *list_p = entry;
45 list_p = &entry->next;
46 }
47 return ret;
48}
49static int entcmp(const char *name1, int dir1, const char *name2, int dir2)
51{
52 int len1 = strlen(name1);
53 int len2 = strlen(name2);
54 int len = len1 < len2 ? len1 : len2;
55 int ret = memcmp(name1, name2, len);
56 unsigned char c1, c2;
57 if (ret)
58 return ret;
59 c1 = name1[len];
60 c2 = name2[len];
61 if (!c1 && dir1)
62 c1 = '/';
63 if (!c2 && dir2)
64 c2 = '/';
65 ret = (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
66 if (c1 && c2 && !ret)
67 ret = len1 - len2;
68 return ret;
69}
70static int unpack_trees_rec(struct tree_entry_list **posns, int len,
72 const char *base, struct unpack_trees_options *o,
73 int *indpos,
74 struct tree_entry_list *df_conflict_list)
75{
76 int baselen = strlen(base);
77 int src_size = len + 1;
78 int i_stk = i_stk;
79 int retval = 0;
80 if (o->dir)
82 i_stk = push_exclude_per_directory(o->dir, base, strlen(base));
83 do {
85 int i;
86 const char *first;
87 int firstdir = 0;
88 int pathlen;
89 unsigned ce_size;
90 struct tree_entry_list **subposns;
91 struct cache_entry **src;
92 int any_files = 0;
93 int any_dirs = 0;
94 char *cache_name;
95 int ce_stage;
96 /* Find the first name in the input. */
98 first = NULL;
100 cache_name = NULL;
101 /* Check the cache */
103 if (o->merge && *indpos < active_nr) {
104 /* This is a bit tricky: */
105 /* If the index has a subdirectory (with
106 * contents) as the first name, it'll get a
107 * filename like "foo/bar". But that's after
108 * "foo", so the entry in trees will get
109 * handled first, at which point we'll go into
110 * "foo", and deal with "bar" from the index,
111 * because the base will be "foo/". The only
112 * way we can actually have "foo/bar" first of
113 * all the things is if the trees don't
114 * contain "foo" at all, in which case we'll
115 * handle "foo/bar" without going into the
116 * directory, but that's fine (and will return
117 * an error anyway, with the added unknown
118 * file case.
119 */
120 cache_name = active_cache[*indpos]->name;
122 if (strlen(cache_name) > baselen &&
123 !memcmp(cache_name, base, baselen)) {
124 cache_name += baselen;
125 first = cache_name;
126 } else {
127 cache_name = NULL;
128 }
129 }
130#if DBRT_DEBUG > 1
132 if (first)
133 printf("index %s\n", first);
134#endif
135 for (i = 0; i < len; i++) {
136 if (!posns[i] || posns[i] == df_conflict_list)
137 continue;
138#if DBRT_DEBUG > 1
139 printf("%d %s\n", i + 1, posns[i]->name);
140#endif
141 if (!first || entcmp(first, firstdir,
142 posns[i]->name,
143 posns[i]->directory) > 0) {
144 first = posns[i]->name;
145 firstdir = posns[i]->directory;
146 }
147 }
148 /* No name means we're done */
149 if (!first)
150 goto leave_directory;
151 pathlen = strlen(first);
153 ce_size = cache_entry_size(baselen + pathlen);
154 src = xcalloc(src_size, sizeof(struct cache_entry *));
156 subposns = xcalloc(len, sizeof(struct tree_list_entry *));
158 if (cache_name && !strcmp(cache_name, first)) {
160 any_files = 1;
161 src[0] = active_cache[*indpos];
162 remove_cache_entry_at(*indpos);
163 }
164 for (i = 0; i < len; i++) {
166 struct cache_entry *ce;
167 if (!posns[i] ||
169 (posns[i] != df_conflict_list &&
170 strcmp(first, posns[i]->name))) {
171 continue;
172 }
173 if (posns[i] == df_conflict_list) {
175 src[i + o->merge] = o->df_conflict_entry;
176 continue;
177 }
178 if (posns[i]->directory) {
180 struct tree *tree = lookup_tree(posns[i]->sha1);
181 any_dirs = 1;
182 parse_tree(tree);
183 subposns[i] = create_tree_entry_list(tree);
184 posns[i] = posns[i]->next;
185 src[i + o->merge] = o->df_conflict_entry;
186 continue;
187 }
188 if (!o->merge)
190 ce_stage = 0;
191 else if (i + 1 < o->head_idx)
192 ce_stage = 1;
193 else if (i + 1 > o->head_idx)
194 ce_stage = 3;
195 else
196 ce_stage = 2;
197 ce = xcalloc(1, ce_size);
199 ce->ce_mode = create_ce_mode(posns[i]->mode);
200 ce->ce_flags = create_ce_flags(baselen + pathlen,
201 ce_stage);
202 memcpy(ce->name, base, baselen);
203 memcpy(ce->name + baselen, first, pathlen + 1);
204 any_files = 1;
206 hashcpy(ce->sha1, posns[i]->sha1);
208 src[i + o->merge] = ce;
209 subposns[i] = df_conflict_list;
210 posns[i] = posns[i]->next;
211 }
212 if (any_files) {
213 if (o->merge) {
214 int ret;
215#if DBRT_DEBUG > 1
217 printf("%s:\n", first);
218 for (i = 0; i < src_size; i++) {
219 printf(" %d ", i);
220 if (src[i])
221 printf("%s\n", sha1_to_hex(src[i]->sha1));
222 else
223 printf("\n");
224 }
225#endif
226 ret = o->fn(src, o);
227#if DBRT_DEBUG > 1
229 printf("Added %d entries\n", ret);
230#endif
231 *indpos += ret;
232 } else {
233 for (i = 0; i < src_size; i++) {
234 if (src[i]) {
235 add_cache_entry(src[i], ADD_CACHE_OK_TO_ADD|ADD_CACHE_SKIP_DFCHECK);
236 }
237 }
238 }
239 }
240 if (any_dirs) {
241 char *newbase = xmalloc(baselen + 2 + pathlen);
242 memcpy(newbase, base, baselen);
243 memcpy(newbase + baselen, first, pathlen);
244 newbase[baselen + pathlen] = '/';
245 newbase[baselen + pathlen + 1] = '\0';
246 if (unpack_trees_rec(subposns, len, newbase, o,
247 indpos, df_conflict_list)) {
248 retval = -1;
249 goto leave_directory;
250 }
251 free(newbase);
252 }
253 free(subposns);
254 free(src);
255 } while (1);
256 leave_directory:
258 if (o->dir)
259 pop_exclude_per_directory(o->dir, i_stk);
260 return retval;
261}
262/* Unlink the last component and attempt to remove leading
264 * directories, in case this unlink is the removal of the
265 * last entry in the directory -- empty directories are removed.
266 */
267static void unlink_entry(char *name)
268{
269 char *cp, *prev;
270 if (unlink(name))
272 return;
273 prev = NULL;
274 while (1) {
275 int status;
276 cp = strrchr(name, '/');
277 if (prev)
278 *prev = '/';
279 if (!cp)
280 break;
281 *cp = 0;
283 status = rmdir(name);
284 if (status) {
285 *cp = '/';
286 break;
287 }
288 prev = cp;
289 }
290}
291static volatile sig_atomic_t progress_update;
293static void progress_interval(int signum)
295{
296 progress_update = 1;
297}
298static void setup_progress_signal(void)
300{
301 struct sigaction sa;
302 struct itimerval v;
303 memset(&sa, 0, sizeof(sa));
305 sa.sa_handler = progress_interval;
306 sigemptyset(&sa.sa_mask);
307 sa.sa_flags = SA_RESTART;
308 sigaction(SIGALRM, &sa, NULL);
309 v.it_interval.tv_sec = 1;
311 v.it_interval.tv_usec = 0;
312 v.it_value = v.it_interval;
313 setitimer(ITIMER_REAL, &v, NULL);
314}
315static struct checkout state;
317static void check_updates(struct cache_entry **src, int nr,
318 struct unpack_trees_options *o)
319{
320 unsigned short mask = htons(CE_UPDATE);
321 unsigned last_percent = 200, cnt = 0, total = 0;
322 if (o->update && o->verbose_update) {
324 for (total = cnt = 0; cnt < nr; cnt++) {
325 struct cache_entry *ce = src[cnt];
326 if (!ce->ce_mode || ce->ce_flags & mask)
327 total++;
328 }
329 /* Don't bother doing this for very small updates */
331 if (total < 250)
332 total = 0;
333 if (total) {
335 fprintf(stderr, "Checking files out...\n");
336 setup_progress_signal();
337 progress_update = 1;
338 }
339 cnt = 0;
340 }
341 while (nr--) {
343 struct cache_entry *ce = *src++;
344 if (total) {
346 if (!ce->ce_mode || ce->ce_flags & mask) {
347 unsigned percent;
348 cnt++;
349 percent = (cnt * 100) / total;
350 if (percent != last_percent ||
351 progress_update) {
352 fprintf(stderr, "%4u%% (%u/%u) done\r",
353 percent, cnt, total);
354 last_percent = percent;
355 progress_update = 0;
356 }
357 }
358 }
359 if (!ce->ce_mode) {
360 if (o->update)
361 unlink_entry(ce->name);
362 continue;
363 }
364 if (ce->ce_flags & mask) {
365 ce->ce_flags &= ~mask;
366 if (o->update)
367 checkout_entry(ce, &state, NULL);
368 }
369 }
370 if (total) {
371 signal(SIGALRM, SIG_IGN);
372 fputc('\n', stderr);
373 }
374}
375int unpack_trees(struct object_list *trees, struct unpack_trees_options *o)
377{
378 int indpos = 0;
379 unsigned len = object_list_length(trees);
380 struct tree_entry_list **posns;
381 int i;
382 struct object_list *posn = trees;
383 struct tree_entry_list df_conflict_list;
384 static struct cache_entry *dfc;
385 memset(&df_conflict_list, 0, sizeof(df_conflict_list));
387 df_conflict_list.next = &df_conflict_list;
388 memset(&state, 0, sizeof(state));
389 state.base_dir = "";
390 state.force = 1;
391 state.quiet = 1;
392 state.refresh_cache = 1;
393 o->merge_size = len;
395 if (!dfc)
397 dfc = xcalloc(1, sizeof(struct cache_entry) + 1);
398 o->df_conflict_entry = dfc;
399 if (len) {
401 posns = xmalloc(len * sizeof(struct tree_entry_list *));
402 for (i = 0; i < len; i++) {
403 posns[i] = create_tree_entry_list((struct tree *) posn->item);
404 posn = posn->next;
405 }
406 if (unpack_trees_rec(posns, len, o->prefix ? o->prefix : "",
407 o, &indpos, &df_conflict_list))
408 return -1;
409 }
410 if (o->trivial_merges_only && o->nontrivial_merge)
412 die("Merge requires file-level merging");
413 check_updates(active_cache, active_nr, o);
415 return 0;
416}
417/* Here come the merge functions */
419static void reject_merge(struct cache_entry *ce)
421{
422 die("Entry '%s' would be overwritten by merge. Cannot merge.",
423 ce->name);
424}
425static int same(struct cache_entry *a, struct cache_entry *b)
427{
428 if (!!a != !!b)
429 return 0;
430 if (!a && !b)
431 return 1;
432 return a->ce_mode == b->ce_mode &&
433 !hashcmp(a->sha1, b->sha1);
434}
435/*
438 * When a CE gets turned into an unmerged entry, we
439 * want it to be up-to-date
440 */
441static void verify_uptodate(struct cache_entry *ce,
442 struct unpack_trees_options *o)
443{
444 struct stat st;
445 if (o->index_only || o->reset)
447 return;
448 if (!lstat(ce->name, &st)) {
450 unsigned changed = ce_match_stat(ce, &st, 1);
451 if (!changed)
452 return;
453 errno = 0;
454 }
455 if (errno == ENOENT)
456 return;
457 die("Entry '%s' not uptodate. Cannot merge.", ce->name);
458}
459static void invalidate_ce_path(struct cache_entry *ce)
461{
462 if (ce)
463 cache_tree_invalidate_path(active_cache_tree, ce->name);
464}
465/*
467 * We do not want to remove or overwrite a working tree file that
468 * is not tracked, unless it is ignored.
469 */
470static void verify_absent(const char *path, const char *action,
471 struct unpack_trees_options *o)
472{
473 struct stat st;
474 if (o->index_only || o->reset || !o->update)
476 return;
477 if (!lstat(path, &st) && !(o->dir && excluded(o->dir, path)))
478 die("Untracked working tree file '%s' "
479 "would be %s by merge.", path, action);
480}
481static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
483 struct unpack_trees_options *o)
484{
485 merge->ce_flags |= htons(CE_UPDATE);
486 if (old) {
487 /*
488 * See if we can re-use the old CE directly?
489 * That way we get the uptodate stat info.
490 *
491 * This also removes the UPDATE flag on
492 * a match.
493 */
494 if (same(old, merge)) {
495 *merge = *old;
496 } else {
497 verify_uptodate(old, o);
498 invalidate_ce_path(old);
499 }
500 }
501 else {
502 verify_absent(merge->name, "overwritten", o);
503 invalidate_ce_path(merge);
504 }
505 merge->ce_flags &= ~htons(CE_STAGEMASK);
507 add_cache_entry(merge, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
508 return 1;
509}
510static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
512 struct unpack_trees_options *o)
513{
514 if (old)
515 verify_uptodate(old, o);
516 else
517 verify_absent(ce->name, "removed", o);
518 ce->ce_mode = 0;
519 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
520 invalidate_ce_path(ce);
521 return 1;
522}
523static int keep_entry(struct cache_entry *ce)
525{
526 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD);
527 return 1;
528}
529#if DBRT_DEBUG
531static void show_stage_entry(FILE *o,
532 const char *label, const struct cache_entry *ce)
533{
534 if (!ce)
535 fprintf(o, "%s (missing)\n", label);
536 else
537 fprintf(o, "%s%06o %s %d\t%s\n",
538 label,
539 ntohl(ce->ce_mode),
540 sha1_to_hex(ce->sha1),
541 ce_stage(ce),
542 ce->name);
543}
544#endif
545int threeway_merge(struct cache_entry **stages,
547 struct unpack_trees_options *o)
548{
549 struct cache_entry *index;
550 struct cache_entry *head;
551 struct cache_entry *remote = stages[o->head_idx + 1];
552 int count;
553 int head_match = 0;
554 int remote_match = 0;
555 const char *path = NULL;
556 int df_conflict_head = 0;
558 int df_conflict_remote = 0;
559 int any_anc_missing = 0;
561 int no_anc_exists = 1;
562 int i;
563 for (i = 1; i < o->head_idx; i++) {
565 if (!stages[i])
566 any_anc_missing = 1;
567 else {
568 if (!path)
569 path = stages[i]->name;
570 no_anc_exists = 0;
571 }
572 }
573 index = stages[0];
575 head = stages[o->head_idx];
576 if (head == o->df_conflict_entry) {
578 df_conflict_head = 1;
579 head = NULL;
580 }
581 if (remote == o->df_conflict_entry) {
583 df_conflict_remote = 1;
584 remote = NULL;
585 }
586 if (!path && index)
588 path = index->name;
589 if (!path && head)
590 path = head->name;
591 if (!path && remote)
592 path = remote->name;
593 /* First, if there's a #16 situation, note that to prevent #13
595 * and #14.
596 */
597 if (!same(remote, head)) {
598 for (i = 1; i < o->head_idx; i++) {
599 if (same(stages[i], head)) {
600 head_match = i;
601 }
602 if (same(stages[i], remote)) {
603 remote_match = i;
604 }
605 }
606 }
607 /* We start with cases where the index is allowed to match
609 * something other than the head: #14(ALT) and #2ALT, where it
610 * is permitted to match the result instead.
611 */
612 /* #14, #14ALT, #2ALT */
613 if (remote && !df_conflict_head && head_match && !remote_match) {
614 if (index && !same(index, remote) && !same(index, head))
615 reject_merge(index);
616 return merged_entry(remote, index, o);
617 }
618 /*
619 * If we have an entry in the index cache, then we want to
620 * make sure that it matches head.
621 */
622 if (index && !same(index, head)) {
623 reject_merge(index);
624 }
625 if (head) {
627 /* #5ALT, #15 */
628 if (same(head, remote))
629 return merged_entry(head, index, o);
630 /* #13, #3ALT */
631 if (!df_conflict_remote && remote_match && !head_match)
632 return merged_entry(head, index, o);
633 }
634 /* #1 */
636 if (!head && !remote && any_anc_missing)
637 return 0;
638 /* Under the new "aggressive" rule, we resolve mostly trivial
640 * cases that we historically had git-merge-one-file resolve.
641 */
642 if (o->aggressive) {
643 int head_deleted = !head && !df_conflict_head;
644 int remote_deleted = !remote && !df_conflict_remote;
645 /*
646 * Deleted in both.
647 * Deleted in one and unchanged in the other.
648 */
649 if ((head_deleted && remote_deleted) ||
650 (head_deleted && remote && remote_match) ||
651 (remote_deleted && head && head_match)) {
652 if (index)
653 return deleted_entry(index, index, o);
654 else if (path && !head_deleted)
655 verify_absent(path, "removed", o);
656 return 0;
657 }
658 /*
659 * Added in both, identically.
660 */
661 if (no_anc_exists && head && remote && same(head, remote))
662 return merged_entry(head, index, o);
663 }
665 /* Below are "no merge" cases, which require that the index be
667 * up-to-date to avoid the files getting overwritten with
668 * conflict resolution files.
669 */
670 if (index) {
671 verify_uptodate(index, o);
672 }
673 o->nontrivial_merge = 1;
675 /* #2, #3, #4, #6, #7, #9, #11. */
677 count = 0;
678 if (!head_match || !remote_match) {
679 for (i = 1; i < o->head_idx; i++) {
680 if (stages[i]) {
681 keep_entry(stages[i]);
682 count++;
683 break;
684 }
685 }
686 }
687#if DBRT_DEBUG
688 else {
689 fprintf(stderr, "read-tree: warning #16 detected\n");
690 show_stage_entry(stderr, "head ", stages[head_match]);
691 show_stage_entry(stderr, "remote ", stages[remote_match]);
692 }
693#endif
694 if (head) { count += keep_entry(head); }
695 if (remote) { count += keep_entry(remote); }
696 return count;
697}
698/*
700 * Two-way merge.
701 *
702 * The rule is to "carry forward" what is in the index without losing
703 * information across a "fast forward", favoring a successful merge
704 * over a merge failure when it makes sense. For details of the
705 * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
706 *
707 */
708int twoway_merge(struct cache_entry **src,
709 struct unpack_trees_options *o)
710{
711 struct cache_entry *current = src[0];
712 struct cache_entry *oldtree = src[1], *newtree = src[2];
713 if (o->merge_size != 2)
715 return error("Cannot do a twoway merge of %d trees",
716 o->merge_size);
717 if (current) {
719 if ((!oldtree && !newtree) || /* 4 and 5 */
720 (!oldtree && newtree &&
721 same(current, newtree)) || /* 6 and 7 */
722 (oldtree && newtree &&
723 same(oldtree, newtree)) || /* 14 and 15 */
724 (oldtree && newtree &&
725 !same(oldtree, newtree) && /* 18 and 19*/
726 same(current, newtree))) {
727 return keep_entry(current);
728 }
729 else if (oldtree && !newtree && same(current, oldtree)) {
730 /* 10 or 11 */
731 return deleted_entry(oldtree, current, o);
732 }
733 else if (oldtree && newtree &&
734 same(current, oldtree) && !same(current, newtree)) {
735 /* 20 or 21 */
736 return merged_entry(newtree, current, o);
737 }
738 else {
739 /* all other failures */
740 if (oldtree)
741 reject_merge(oldtree);
742 if (current)
743 reject_merge(current);
744 if (newtree)
745 reject_merge(newtree);
746 return -1;
747 }
748 }
749 else if (newtree)
750 return merged_entry(newtree, current, o);
751 else
752 return deleted_entry(oldtree, current, o);
753}
754/*
756 * Bind merge.
757 *
758 * Keep the index entries at stage0, collapse stage1 but make sure
759 * stage0 does not have anything there.
760 */
761int bind_merge(struct cache_entry **src,
762 struct unpack_trees_options *o)
763{
764 struct cache_entry *old = src[0];
765 struct cache_entry *a = src[1];
766 if (o->merge_size != 1)
768 return error("Cannot do a bind merge of %d trees\n",
769 o->merge_size);
770 if (a && old)
771 die("Entry '%s' overlaps. Cannot bind.", a->name);
772 if (!a)
773 return keep_entry(old);
774 else
775 return merged_entry(a, NULL, o);
776}
777/*
779 * One-way merge.
780 *
781 * The rule is:
782 * - take the stat information from stage0, take the data from stage1
783 */
784int oneway_merge(struct cache_entry **src,
785 struct unpack_trees_options *o)
786{
787 struct cache_entry *old = src[0];
788 struct cache_entry *a = src[1];
789 if (o->merge_size != 1)
791 return error("Cannot do a oneway merge of %d trees",
792 o->merge_size);
793 if (!a)
795 return deleted_entry(old, old, o);
796 if (old && same(old, a)) {
797 if (o->reset) {
798 struct stat st;
799 if (lstat(old->name, &st) ||
800 ce_match_stat(old, &st, 1))
801 old->ce_flags |= htons(CE_UPDATE);
802 }
803 return keep_entry(old);
804 }
805 return merged_entry(a, old, o);
806}