gitweb: Add git_merge sub
[git/gsoc2010-gitweb.git] / unpack-trees.c
blob85045fd03fd7ab2a2ad8daf5ec584e010372673b
1 #define NO_THE_INDEX_COMPATIBILITY_MACROS
2 #include "cache.h"
3 #include "dir.h"
4 #include "tree.h"
5 #include "tree-walk.h"
6 #include "cache-tree.h"
7 #include "unpack-trees.h"
8 #include "progress.h"
9 #include "refs.h"
10 #include "attr.h"
13 * Error messages expected by scripts out of plumbing commands such as
14 * read-tree. Non-scripted Porcelain is not required to use these messages
15 * and in fact are encouraged to reword them to better suit their particular
16 * situation better. See how "git checkout" replaces not_uptodate_file to
17 * explain why it does not allow switching between branches when you have
18 * local changes, for example.
20 static struct unpack_trees_error_msgs unpack_plumbing_errors = {
21 /* would_overwrite */
22 "Entry '%s' would be overwritten by merge. Cannot merge.",
24 /* not_uptodate_file */
25 "Entry '%s' not uptodate. Cannot merge.",
27 /* not_uptodate_dir */
28 "Updating '%s' would lose untracked files in it",
30 /* would_lose_untracked */
31 "Untracked working tree file '%s' would be %s by merge.",
33 /* bind_overlap */
34 "Entry '%s' overlaps with '%s'. Cannot bind.",
36 /* sparse_not_uptodate_file */
37 "Entry '%s' not uptodate. Cannot update sparse checkout.",
39 /* would_lose_orphaned */
40 "Working tree file '%s' would be %s by sparse checkout update.",
43 #define ERRORMSG(o,fld) \
44 ( ((o) && (o)->msgs.fld) \
45 ? ((o)->msgs.fld) \
46 : (unpack_plumbing_errors.fld) )
48 static void add_entry(struct unpack_trees_options *o, struct cache_entry *ce,
49 unsigned int set, unsigned int clear)
51 unsigned int size = ce_size(ce);
52 struct cache_entry *new = xmalloc(size);
54 clear |= CE_HASHED | CE_UNHASHED;
56 memcpy(new, ce, size);
57 new->next = NULL;
58 new->ce_flags = (new->ce_flags & ~clear) | set;
59 add_index_entry(&o->result, new, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
63 * Unlink the last component and schedule the leading directories for
64 * removal, such that empty directories get removed.
66 static void unlink_entry(struct cache_entry *ce)
68 if (has_symlink_or_noent_leading_path(ce->name, ce_namelen(ce)))
69 return;
70 if (remove_or_warn(ce->ce_mode, ce->name))
71 return;
72 schedule_dir_for_removal(ce->name, ce_namelen(ce));
75 static struct checkout state;
76 static int check_updates(struct unpack_trees_options *o)
78 unsigned cnt = 0, total = 0;
79 struct progress *progress = NULL;
80 struct index_state *index = &o->result;
81 int i;
82 int errs = 0;
84 if (o->update && o->verbose_update) {
85 for (total = cnt = 0; cnt < index->cache_nr; cnt++) {
86 struct cache_entry *ce = index->cache[cnt];
87 if (ce->ce_flags & (CE_UPDATE | CE_REMOVE | CE_WT_REMOVE))
88 total++;
91 progress = start_progress_delay("Checking out files",
92 total, 50, 1);
93 cnt = 0;
96 if (o->update)
97 git_attr_set_direction(GIT_ATTR_CHECKOUT, &o->result);
98 for (i = 0; i < index->cache_nr; i++) {
99 struct cache_entry *ce = index->cache[i];
101 if (ce->ce_flags & CE_WT_REMOVE) {
102 display_progress(progress, ++cnt);
103 if (o->update)
104 unlink_entry(ce);
105 continue;
108 if (ce->ce_flags & CE_REMOVE) {
109 display_progress(progress, ++cnt);
110 if (o->update)
111 unlink_entry(ce);
114 remove_marked_cache_entries(&o->result);
115 remove_scheduled_dirs();
117 for (i = 0; i < index->cache_nr; i++) {
118 struct cache_entry *ce = index->cache[i];
120 if (ce->ce_flags & CE_UPDATE) {
121 display_progress(progress, ++cnt);
122 ce->ce_flags &= ~CE_UPDATE;
123 if (o->update) {
124 errs |= checkout_entry(ce, &state, NULL);
128 stop_progress(&progress);
129 if (o->update)
130 git_attr_set_direction(GIT_ATTR_CHECKIN, NULL);
131 return errs != 0;
134 static int verify_uptodate_sparse(struct cache_entry *ce, struct unpack_trees_options *o);
135 static int verify_absent_sparse(struct cache_entry *ce, const char *action, struct unpack_trees_options *o);
137 static int will_have_skip_worktree(const struct cache_entry *ce, struct unpack_trees_options *o)
139 const char *basename;
141 if (ce_stage(ce))
142 return 0;
144 basename = strrchr(ce->name, '/');
145 basename = basename ? basename+1 : ce->name;
146 return excluded_from_list(ce->name, ce_namelen(ce), basename, NULL, o->el) <= 0;
149 static int apply_sparse_checkout(struct cache_entry *ce, struct unpack_trees_options *o)
151 int was_skip_worktree = ce_skip_worktree(ce);
153 if (will_have_skip_worktree(ce, o))
154 ce->ce_flags |= CE_SKIP_WORKTREE;
155 else
156 ce->ce_flags &= ~CE_SKIP_WORKTREE;
159 * We only care about files getting into the checkout area
160 * If merge strategies want to remove some, go ahead, this
161 * flag will be removed eventually in unpack_trees() if it's
162 * outside checkout area.
164 if (ce->ce_flags & CE_REMOVE)
165 return 0;
167 if (!was_skip_worktree && ce_skip_worktree(ce)) {
169 * If CE_UPDATE is set, verify_uptodate() must be called already
170 * also stat info may have lost after merged_entry() so calling
171 * verify_uptodate() again may fail
173 if (!(ce->ce_flags & CE_UPDATE) && verify_uptodate_sparse(ce, o))
174 return -1;
175 ce->ce_flags |= CE_WT_REMOVE;
177 if (was_skip_worktree && !ce_skip_worktree(ce)) {
178 if (verify_absent_sparse(ce, "overwritten", o))
179 return -1;
180 ce->ce_flags |= CE_UPDATE;
182 return 0;
185 static inline int call_unpack_fn(struct cache_entry **src, struct unpack_trees_options *o)
187 int ret = o->fn(src, o);
188 if (ret > 0)
189 ret = 0;
190 return ret;
193 static void mark_ce_used(struct cache_entry *ce, struct unpack_trees_options *o)
195 ce->ce_flags |= CE_UNPACKED;
197 if (o->cache_bottom < o->src_index->cache_nr &&
198 o->src_index->cache[o->cache_bottom] == ce) {
199 int bottom = o->cache_bottom;
200 while (bottom < o->src_index->cache_nr &&
201 o->src_index->cache[bottom]->ce_flags & CE_UNPACKED)
202 bottom++;
203 o->cache_bottom = bottom;
207 static void mark_all_ce_unused(struct index_state *index)
209 int i;
210 for (i = 0; i < index->cache_nr; i++)
211 index->cache[i]->ce_flags &= ~CE_UNPACKED;
214 static int locate_in_src_index(struct cache_entry *ce,
215 struct unpack_trees_options *o)
217 struct index_state *index = o->src_index;
218 int len = ce_namelen(ce);
219 int pos = index_name_pos(index, ce->name, len);
220 if (pos < 0)
221 pos = -1 - pos;
222 return pos;
226 * We call unpack_index_entry() with an unmerged cache entry
227 * only in diff-index, and it wants a single callback. Skip
228 * the other unmerged entry with the same name.
230 static void mark_ce_used_same_name(struct cache_entry *ce,
231 struct unpack_trees_options *o)
233 struct index_state *index = o->src_index;
234 int len = ce_namelen(ce);
235 int pos;
237 for (pos = locate_in_src_index(ce, o); pos < index->cache_nr; pos++) {
238 struct cache_entry *next = index->cache[pos];
239 if (len != ce_namelen(next) ||
240 memcmp(ce->name, next->name, len))
241 break;
242 mark_ce_used(next, o);
246 static struct cache_entry *next_cache_entry(struct unpack_trees_options *o)
248 const struct index_state *index = o->src_index;
249 int pos = o->cache_bottom;
251 while (pos < index->cache_nr) {
252 struct cache_entry *ce = index->cache[pos];
253 if (!(ce->ce_flags & CE_UNPACKED))
254 return ce;
255 pos++;
257 return NULL;
260 static void add_same_unmerged(struct cache_entry *ce,
261 struct unpack_trees_options *o)
263 struct index_state *index = o->src_index;
264 int len = ce_namelen(ce);
265 int pos = index_name_pos(index, ce->name, len);
267 if (0 <= pos)
268 die("programming error in a caller of mark_ce_used_same_name");
269 for (pos = -pos - 1; pos < index->cache_nr; pos++) {
270 struct cache_entry *next = index->cache[pos];
271 if (len != ce_namelen(next) ||
272 memcmp(ce->name, next->name, len))
273 break;
274 add_entry(o, next, 0, 0);
275 mark_ce_used(next, o);
279 static int unpack_index_entry(struct cache_entry *ce,
280 struct unpack_trees_options *o)
282 struct cache_entry *src[5] = { NULL };
283 int ret;
285 src[0] = ce;
287 mark_ce_used(ce, o);
288 if (ce_stage(ce)) {
289 if (o->skip_unmerged) {
290 add_entry(o, ce, 0, 0);
291 return 0;
294 ret = call_unpack_fn(src, o);
295 if (ce_stage(ce))
296 mark_ce_used_same_name(ce, o);
297 return ret;
300 static int find_cache_pos(struct traverse_info *, const struct name_entry *);
302 static void restore_cache_bottom(struct traverse_info *info, int bottom)
304 struct unpack_trees_options *o = info->data;
306 if (o->diff_index_cached)
307 return;
308 o->cache_bottom = bottom;
311 static int switch_cache_bottom(struct traverse_info *info)
313 struct unpack_trees_options *o = info->data;
314 int ret, pos;
316 if (o->diff_index_cached)
317 return 0;
318 ret = o->cache_bottom;
319 pos = find_cache_pos(info->prev, &info->name);
321 if (pos < -1)
322 o->cache_bottom = -2 - pos;
323 else if (pos < 0)
324 o->cache_bottom = o->src_index->cache_nr;
325 return ret;
328 static int traverse_trees_recursive(int n, unsigned long dirmask, unsigned long df_conflicts, struct name_entry *names, struct traverse_info *info)
330 int i, ret, bottom;
331 struct tree_desc t[MAX_UNPACK_TREES];
332 struct traverse_info newinfo;
333 struct name_entry *p;
335 p = names;
336 while (!p->mode)
337 p++;
339 newinfo = *info;
340 newinfo.prev = info;
341 newinfo.name = *p;
342 newinfo.pathlen += tree_entry_len(p->path, p->sha1) + 1;
343 newinfo.conflicts |= df_conflicts;
345 for (i = 0; i < n; i++, dirmask >>= 1) {
346 const unsigned char *sha1 = NULL;
347 if (dirmask & 1)
348 sha1 = names[i].sha1;
349 fill_tree_descriptor(t+i, sha1);
352 bottom = switch_cache_bottom(&newinfo);
353 ret = traverse_trees(n, t, &newinfo);
354 restore_cache_bottom(&newinfo, bottom);
355 return ret;
359 * Compare the traverse-path to the cache entry without actually
360 * having to generate the textual representation of the traverse
361 * path.
363 * NOTE! This *only* compares up to the size of the traverse path
364 * itself - the caller needs to do the final check for the cache
365 * entry having more data at the end!
367 static int do_compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
369 int len, pathlen, ce_len;
370 const char *ce_name;
372 if (info->prev) {
373 int cmp = do_compare_entry(ce, info->prev, &info->name);
374 if (cmp)
375 return cmp;
377 pathlen = info->pathlen;
378 ce_len = ce_namelen(ce);
380 /* If ce_len < pathlen then we must have previously hit "name == directory" entry */
381 if (ce_len < pathlen)
382 return -1;
384 ce_len -= pathlen;
385 ce_name = ce->name + pathlen;
387 len = tree_entry_len(n->path, n->sha1);
388 return df_name_compare(ce_name, ce_len, S_IFREG, n->path, len, n->mode);
391 static int compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
393 int cmp = do_compare_entry(ce, info, n);
394 if (cmp)
395 return cmp;
398 * Even if the beginning compared identically, the ce should
399 * compare as bigger than a directory leading up to it!
401 return ce_namelen(ce) > traverse_path_len(info, n);
404 static int ce_in_traverse_path(const struct cache_entry *ce,
405 const struct traverse_info *info)
407 if (!info->prev)
408 return 1;
409 if (do_compare_entry(ce, info->prev, &info->name))
410 return 0;
412 * If ce (blob) is the same name as the path (which is a tree
413 * we will be descending into), it won't be inside it.
415 return (info->pathlen < ce_namelen(ce));
418 static struct cache_entry *create_ce_entry(const struct traverse_info *info, const struct name_entry *n, int stage)
420 int len = traverse_path_len(info, n);
421 struct cache_entry *ce = xcalloc(1, cache_entry_size(len));
423 ce->ce_mode = create_ce_mode(n->mode);
424 ce->ce_flags = create_ce_flags(len, stage);
425 hashcpy(ce->sha1, n->sha1);
426 make_traverse_path(ce->name, info, n);
428 return ce;
431 static int unpack_nondirectories(int n, unsigned long mask,
432 unsigned long dirmask,
433 struct cache_entry **src,
434 const struct name_entry *names,
435 const struct traverse_info *info)
437 int i;
438 struct unpack_trees_options *o = info->data;
439 unsigned long conflicts;
441 /* Do we have *only* directories? Nothing to do */
442 if (mask == dirmask && !src[0])
443 return 0;
445 conflicts = info->conflicts;
446 if (o->merge)
447 conflicts >>= 1;
448 conflicts |= dirmask;
451 * Ok, we've filled in up to any potential index entry in src[0],
452 * now do the rest.
454 for (i = 0; i < n; i++) {
455 int stage;
456 unsigned int bit = 1ul << i;
457 if (conflicts & bit) {
458 src[i + o->merge] = o->df_conflict_entry;
459 continue;
461 if (!(mask & bit))
462 continue;
463 if (!o->merge)
464 stage = 0;
465 else if (i + 1 < o->head_idx)
466 stage = 1;
467 else if (i + 1 > o->head_idx)
468 stage = 3;
469 else
470 stage = 2;
471 src[i + o->merge] = create_ce_entry(info, names + i, stage);
474 if (o->merge)
475 return call_unpack_fn(src, o);
477 for (i = 0; i < n; i++)
478 if (src[i] && src[i] != o->df_conflict_entry)
479 add_entry(o, src[i], 0, 0);
480 return 0;
483 static int unpack_failed(struct unpack_trees_options *o, const char *message)
485 discard_index(&o->result);
486 if (!o->gently) {
487 if (message)
488 return error("%s", message);
489 return -1;
491 return -1;
494 /* NEEDSWORK: give this a better name and share with tree-walk.c */
495 static int name_compare(const char *a, int a_len,
496 const char *b, int b_len)
498 int len = (a_len < b_len) ? a_len : b_len;
499 int cmp = memcmp(a, b, len);
500 if (cmp)
501 return cmp;
502 return (a_len - b_len);
506 * The tree traversal is looking at name p. If we have a matching entry,
507 * return it. If name p is a directory in the index, do not return
508 * anything, as we will want to match it when the traversal descends into
509 * the directory.
511 static int find_cache_pos(struct traverse_info *info,
512 const struct name_entry *p)
514 int pos;
515 struct unpack_trees_options *o = info->data;
516 struct index_state *index = o->src_index;
517 int pfxlen = info->pathlen;
518 int p_len = tree_entry_len(p->path, p->sha1);
520 for (pos = o->cache_bottom; pos < index->cache_nr; pos++) {
521 struct cache_entry *ce = index->cache[pos];
522 const char *ce_name, *ce_slash;
523 int cmp, ce_len;
525 if (!ce_in_traverse_path(ce, info))
526 continue;
527 if (ce->ce_flags & CE_UNPACKED)
528 continue;
529 ce_name = ce->name + pfxlen;
530 ce_slash = strchr(ce_name, '/');
531 if (ce_slash)
532 ce_len = ce_slash - ce_name;
533 else
534 ce_len = ce_namelen(ce) - pfxlen;
535 cmp = name_compare(p->path, p_len, ce_name, ce_len);
537 * Exact match; if we have a directory we need to
538 * delay returning it.
540 if (!cmp)
541 return ce_slash ? -2 - pos : pos;
542 if (0 < cmp)
543 continue; /* keep looking */
545 * ce_name sorts after p->path; could it be that we
546 * have files under p->path directory in the index?
547 * E.g. ce_name == "t-i", and p->path == "t"; we may
548 * have "t/a" in the index.
550 if (p_len < ce_len && !memcmp(ce_name, p->path, p_len) &&
551 ce_name[p_len] < '/')
552 continue; /* keep looking */
553 break;
555 return -1;
558 static struct cache_entry *find_cache_entry(struct traverse_info *info,
559 const struct name_entry *p)
561 int pos = find_cache_pos(info, p);
562 struct unpack_trees_options *o = info->data;
564 if (0 <= pos)
565 return o->src_index->cache[pos];
566 else
567 return NULL;
570 static void debug_path(struct traverse_info *info)
572 if (info->prev) {
573 debug_path(info->prev);
574 if (*info->prev->name.path)
575 putchar('/');
577 printf("%s", info->name.path);
580 static void debug_name_entry(int i, struct name_entry *n)
582 printf("ent#%d %06o %s\n", i,
583 n->path ? n->mode : 0,
584 n->path ? n->path : "(missing)");
587 static void debug_unpack_callback(int n,
588 unsigned long mask,
589 unsigned long dirmask,
590 struct name_entry *names,
591 struct traverse_info *info)
593 int i;
594 printf("* unpack mask %lu, dirmask %lu, cnt %d ",
595 mask, dirmask, n);
596 debug_path(info);
597 putchar('\n');
598 for (i = 0; i < n; i++)
599 debug_name_entry(i, names + i);
602 static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *names, struct traverse_info *info)
604 struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
605 struct unpack_trees_options *o = info->data;
606 const struct name_entry *p = names;
608 /* Find first entry with a real name (we could use "mask" too) */
609 while (!p->mode)
610 p++;
612 if (o->debug_unpack)
613 debug_unpack_callback(n, mask, dirmask, names, info);
615 /* Are we supposed to look at the index too? */
616 if (o->merge) {
617 while (1) {
618 int cmp;
619 struct cache_entry *ce;
621 if (o->diff_index_cached)
622 ce = next_cache_entry(o);
623 else
624 ce = find_cache_entry(info, p);
626 if (!ce)
627 break;
628 cmp = compare_entry(ce, info, p);
629 if (cmp < 0) {
630 if (unpack_index_entry(ce, o) < 0)
631 return unpack_failed(o, NULL);
632 continue;
634 if (!cmp) {
635 if (ce_stage(ce)) {
637 * If we skip unmerged index
638 * entries, we'll skip this
639 * entry *and* the tree
640 * entries associated with it!
642 if (o->skip_unmerged) {
643 add_same_unmerged(ce, o);
644 return mask;
647 src[0] = ce;
649 break;
653 if (unpack_nondirectories(n, mask, dirmask, src, names, info) < 0)
654 return -1;
656 if (src[0]) {
657 if (ce_stage(src[0]))
658 mark_ce_used_same_name(src[0], o);
659 else
660 mark_ce_used(src[0], o);
663 /* Now handle any directories.. */
664 if (dirmask) {
665 unsigned long conflicts = mask & ~dirmask;
666 if (o->merge) {
667 conflicts <<= 1;
668 if (src[0])
669 conflicts |= 1;
672 /* special case: "diff-index --cached" looking at a tree */
673 if (o->diff_index_cached &&
674 n == 1 && dirmask == 1 && S_ISDIR(names->mode)) {
675 int matches;
676 matches = cache_tree_matches_traversal(o->src_index->cache_tree,
677 names, info);
679 * Everything under the name matches; skip the
680 * entire hierarchy. diff_index_cached codepath
681 * special cases D/F conflicts in such a way that
682 * it does not do any look-ahead, so this is safe.
684 if (matches) {
685 o->cache_bottom += matches;
686 return mask;
690 if (traverse_trees_recursive(n, dirmask, conflicts,
691 names, info) < 0)
692 return -1;
693 return mask;
696 return mask;
700 * N-way merge "len" trees. Returns 0 on success, -1 on failure to manipulate the
701 * resulting index, -2 on failure to reflect the changes to the work tree.
703 int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o)
705 int i, ret;
706 static struct cache_entry *dfc;
707 struct exclude_list el;
709 if (len > MAX_UNPACK_TREES)
710 die("unpack_trees takes at most %d trees", MAX_UNPACK_TREES);
711 memset(&state, 0, sizeof(state));
712 state.base_dir = "";
713 state.force = 1;
714 state.quiet = 1;
715 state.refresh_cache = 1;
717 memset(&el, 0, sizeof(el));
718 if (!core_apply_sparse_checkout || !o->update)
719 o->skip_sparse_checkout = 1;
720 if (!o->skip_sparse_checkout) {
721 if (add_excludes_from_file_to_list(git_path("info/sparse-checkout"), "", 0, NULL, &el, 0) < 0)
722 o->skip_sparse_checkout = 1;
723 else
724 o->el = &el;
727 memset(&o->result, 0, sizeof(o->result));
728 o->result.initialized = 1;
729 o->result.timestamp.sec = o->src_index->timestamp.sec;
730 o->result.timestamp.nsec = o->src_index->timestamp.nsec;
731 o->merge_size = len;
732 mark_all_ce_unused(o->src_index);
734 if (!dfc)
735 dfc = xcalloc(1, cache_entry_size(0));
736 o->df_conflict_entry = dfc;
738 if (len) {
739 const char *prefix = o->prefix ? o->prefix : "";
740 struct traverse_info info;
742 setup_traverse_info(&info, prefix);
743 info.fn = unpack_callback;
744 info.data = o;
746 if (o->prefix) {
748 * Unpack existing index entries that sort before the
749 * prefix the tree is spliced into. Note that o->merge
750 * is always true in this case.
752 while (1) {
753 struct cache_entry *ce = next_cache_entry(o);
754 if (!ce)
755 break;
756 if (ce_in_traverse_path(ce, &info))
757 break;
758 if (unpack_index_entry(ce, o) < 0)
759 goto return_failed;
763 if (traverse_trees(len, t, &info) < 0)
764 goto return_failed;
767 /* Any left-over entries in the index? */
768 if (o->merge) {
769 while (1) {
770 struct cache_entry *ce = next_cache_entry(o);
771 if (!ce)
772 break;
773 if (unpack_index_entry(ce, o) < 0)
774 goto return_failed;
777 mark_all_ce_unused(o->src_index);
779 if (o->trivial_merges_only && o->nontrivial_merge) {
780 ret = unpack_failed(o, "Merge requires file-level merging");
781 goto done;
784 if (!o->skip_sparse_checkout) {
785 int empty_worktree = 1;
786 for (i = 0;i < o->result.cache_nr;i++) {
787 struct cache_entry *ce = o->result.cache[i];
789 if (apply_sparse_checkout(ce, o)) {
790 ret = -1;
791 goto done;
794 * Merge strategies may set CE_UPDATE|CE_REMOVE outside checkout
795 * area as a result of ce_skip_worktree() shortcuts in
796 * verify_absent() and verify_uptodate(). Clear them.
798 if (ce_skip_worktree(ce))
799 ce->ce_flags &= ~(CE_UPDATE | CE_REMOVE);
800 else
801 empty_worktree = 0;
804 if (o->result.cache_nr && empty_worktree) {
805 ret = unpack_failed(o, "Sparse checkout leaves no entry on working directory");
806 goto done;
810 o->src_index = NULL;
811 ret = check_updates(o) ? (-2) : 0;
812 if (o->dst_index)
813 *o->dst_index = o->result;
815 done:
816 for (i = 0;i < el.nr;i++)
817 free(el.excludes[i]);
818 if (el.excludes)
819 free(el.excludes);
821 return ret;
823 return_failed:
824 mark_all_ce_unused(o->src_index);
825 ret = unpack_failed(o, NULL);
826 goto done;
829 /* Here come the merge functions */
831 static int reject_merge(struct cache_entry *ce, struct unpack_trees_options *o)
833 return error(ERRORMSG(o, would_overwrite), ce->name);
836 static int same(struct cache_entry *a, struct cache_entry *b)
838 if (!!a != !!b)
839 return 0;
840 if (!a && !b)
841 return 1;
842 if ((a->ce_flags | b->ce_flags) & CE_CONFLICTED)
843 return 0;
844 return a->ce_mode == b->ce_mode &&
845 !hashcmp(a->sha1, b->sha1);
850 * When a CE gets turned into an unmerged entry, we
851 * want it to be up-to-date
853 static int verify_uptodate_1(struct cache_entry *ce,
854 struct unpack_trees_options *o,
855 const char *error_msg)
857 struct stat st;
859 if (o->index_only || (!((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce)) && (o->reset || ce_uptodate(ce))))
860 return 0;
862 if (!lstat(ce->name, &st)) {
863 unsigned changed = ie_match_stat(o->src_index, ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
864 if (!changed)
865 return 0;
867 * NEEDSWORK: the current default policy is to allow
868 * submodule to be out of sync wrt the supermodule
869 * index. This needs to be tightened later for
870 * submodules that are marked to be automatically
871 * checked out.
873 if (S_ISGITLINK(ce->ce_mode))
874 return 0;
875 errno = 0;
877 if (errno == ENOENT)
878 return 0;
879 return o->gently ? -1 :
880 error(error_msg, ce->name);
883 static int verify_uptodate(struct cache_entry *ce,
884 struct unpack_trees_options *o)
886 if (!o->skip_sparse_checkout && will_have_skip_worktree(ce, o))
887 return 0;
888 return verify_uptodate_1(ce, o, ERRORMSG(o, not_uptodate_file));
891 static int verify_uptodate_sparse(struct cache_entry *ce,
892 struct unpack_trees_options *o)
894 return verify_uptodate_1(ce, o, ERRORMSG(o, sparse_not_uptodate_file));
897 static void invalidate_ce_path(struct cache_entry *ce, struct unpack_trees_options *o)
899 if (ce)
900 cache_tree_invalidate_path(o->src_index->cache_tree, ce->name);
904 * Check that checking out ce->sha1 in subdir ce->name is not
905 * going to overwrite any working files.
907 * Currently, git does not checkout subprojects during a superproject
908 * checkout, so it is not going to overwrite anything.
910 static int verify_clean_submodule(struct cache_entry *ce, const char *action,
911 struct unpack_trees_options *o)
913 return 0;
916 static int verify_clean_subdirectory(struct cache_entry *ce, const char *action,
917 struct unpack_trees_options *o)
920 * we are about to extract "ce->name"; we would not want to lose
921 * anything in the existing directory there.
923 int namelen;
924 int i;
925 struct dir_struct d;
926 char *pathbuf;
927 int cnt = 0;
928 unsigned char sha1[20];
930 if (S_ISGITLINK(ce->ce_mode) &&
931 resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) {
932 /* If we are not going to update the submodule, then
933 * we don't care.
935 if (!hashcmp(sha1, ce->sha1))
936 return 0;
937 return verify_clean_submodule(ce, action, o);
941 * First let's make sure we do not have a local modification
942 * in that directory.
944 namelen = strlen(ce->name);
945 for (i = locate_in_src_index(ce, o);
946 i < o->src_index->cache_nr;
947 i++) {
948 struct cache_entry *ce2 = o->src_index->cache[i];
949 int len = ce_namelen(ce2);
950 if (len < namelen ||
951 strncmp(ce->name, ce2->name, namelen) ||
952 ce2->name[namelen] != '/')
953 break;
955 * ce2->name is an entry in the subdirectory to be
956 * removed.
958 if (!ce_stage(ce2)) {
959 if (verify_uptodate(ce2, o))
960 return -1;
961 add_entry(o, ce2, CE_REMOVE, 0);
962 mark_ce_used(ce2, o);
964 cnt++;
968 * Then we need to make sure that we do not lose a locally
969 * present file that is not ignored.
971 pathbuf = xmalloc(namelen + 2);
972 memcpy(pathbuf, ce->name, namelen);
973 strcpy(pathbuf+namelen, "/");
975 memset(&d, 0, sizeof(d));
976 if (o->dir)
977 d.exclude_per_dir = o->dir->exclude_per_dir;
978 i = read_directory(&d, pathbuf, namelen+1, NULL);
979 if (i)
980 return o->gently ? -1 :
981 error(ERRORMSG(o, not_uptodate_dir), ce->name);
982 free(pathbuf);
983 return cnt;
987 * This gets called when there was no index entry for the tree entry 'dst',
988 * but we found a file in the working tree that 'lstat()' said was fine,
989 * and we're on a case-insensitive filesystem.
991 * See if we can find a case-insensitive match in the index that also
992 * matches the stat information, and assume it's that other file!
994 static int icase_exists(struct unpack_trees_options *o, struct cache_entry *dst, struct stat *st)
996 struct cache_entry *src;
998 src = index_name_exists(o->src_index, dst->name, ce_namelen(dst), 1);
999 return src && !ie_match_stat(o->src_index, src, st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
1003 * We do not want to remove or overwrite a working tree file that
1004 * is not tracked, unless it is ignored.
1006 static int verify_absent_1(struct cache_entry *ce, const char *action,
1007 struct unpack_trees_options *o,
1008 const char *error_msg)
1010 struct stat st;
1012 if (o->index_only || o->reset || !o->update)
1013 return 0;
1015 if (has_symlink_or_noent_leading_path(ce->name, ce_namelen(ce)))
1016 return 0;
1018 if (!lstat(ce->name, &st)) {
1019 int dtype = ce_to_dtype(ce);
1020 struct cache_entry *result;
1023 * It may be that the 'lstat()' succeeded even though
1024 * target 'ce' was absent, because there is an old
1025 * entry that is different only in case..
1027 * Ignore that lstat() if it matches.
1029 if (ignore_case && icase_exists(o, ce, &st))
1030 return 0;
1032 if (o->dir && excluded(o->dir, ce->name, &dtype))
1034 * ce->name is explicitly excluded, so it is Ok to
1035 * overwrite it.
1037 return 0;
1038 if (S_ISDIR(st.st_mode)) {
1040 * We are checking out path "foo" and
1041 * found "foo/." in the working tree.
1042 * This is tricky -- if we have modified
1043 * files that are in "foo/" we would lose
1044 * them.
1046 if (verify_clean_subdirectory(ce, action, o) < 0)
1047 return -1;
1048 return 0;
1052 * The previous round may already have decided to
1053 * delete this path, which is in a subdirectory that
1054 * is being replaced with a blob.
1056 result = index_name_exists(&o->result, ce->name, ce_namelen(ce), 0);
1057 if (result) {
1058 if (result->ce_flags & CE_REMOVE)
1059 return 0;
1062 return o->gently ? -1 :
1063 error(ERRORMSG(o, would_lose_untracked), ce->name, action);
1065 return 0;
1067 static int verify_absent(struct cache_entry *ce, const char *action,
1068 struct unpack_trees_options *o)
1070 if (!o->skip_sparse_checkout && will_have_skip_worktree(ce, o))
1071 return 0;
1072 return verify_absent_1(ce, action, o, ERRORMSG(o, would_lose_untracked));
1075 static int verify_absent_sparse(struct cache_entry *ce, const char *action,
1076 struct unpack_trees_options *o)
1078 return verify_absent_1(ce, action, o, ERRORMSG(o, would_lose_orphaned));
1081 static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
1082 struct unpack_trees_options *o)
1084 int update = CE_UPDATE;
1086 if (!old) {
1087 if (verify_absent(merge, "overwritten", o))
1088 return -1;
1089 invalidate_ce_path(merge, o);
1090 } else if (!(old->ce_flags & CE_CONFLICTED)) {
1092 * See if we can re-use the old CE directly?
1093 * That way we get the uptodate stat info.
1095 * This also removes the UPDATE flag on a match; otherwise
1096 * we will end up overwriting local changes in the work tree.
1098 if (same(old, merge)) {
1099 copy_cache_entry(merge, old);
1100 update = 0;
1101 } else {
1102 if (verify_uptodate(old, o))
1103 return -1;
1104 if (ce_skip_worktree(old))
1105 update |= CE_SKIP_WORKTREE;
1106 invalidate_ce_path(old, o);
1108 } else {
1110 * Previously unmerged entry left as an existence
1111 * marker by read_index_unmerged();
1113 invalidate_ce_path(old, o);
1116 add_entry(o, merge, update, CE_STAGEMASK);
1117 return 1;
1120 static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
1121 struct unpack_trees_options *o)
1123 /* Did it exist in the index? */
1124 if (!old) {
1125 if (verify_absent(ce, "removed", o))
1126 return -1;
1127 return 0;
1129 if (!(old->ce_flags & CE_CONFLICTED) && verify_uptodate(old, o))
1130 return -1;
1131 add_entry(o, ce, CE_REMOVE, 0);
1132 invalidate_ce_path(ce, o);
1133 return 1;
1136 static int keep_entry(struct cache_entry *ce, struct unpack_trees_options *o)
1138 add_entry(o, ce, 0, 0);
1139 return 1;
1142 #if DBRT_DEBUG
1143 static void show_stage_entry(FILE *o,
1144 const char *label, const struct cache_entry *ce)
1146 if (!ce)
1147 fprintf(o, "%s (missing)\n", label);
1148 else
1149 fprintf(o, "%s%06o %s %d\t%s\n",
1150 label,
1151 ce->ce_mode,
1152 sha1_to_hex(ce->sha1),
1153 ce_stage(ce),
1154 ce->name);
1156 #endif
1158 int threeway_merge(struct cache_entry **stages, struct unpack_trees_options *o)
1160 struct cache_entry *index;
1161 struct cache_entry *head;
1162 struct cache_entry *remote = stages[o->head_idx + 1];
1163 int count;
1164 int head_match = 0;
1165 int remote_match = 0;
1167 int df_conflict_head = 0;
1168 int df_conflict_remote = 0;
1170 int any_anc_missing = 0;
1171 int no_anc_exists = 1;
1172 int i;
1174 for (i = 1; i < o->head_idx; i++) {
1175 if (!stages[i] || stages[i] == o->df_conflict_entry)
1176 any_anc_missing = 1;
1177 else
1178 no_anc_exists = 0;
1181 index = stages[0];
1182 head = stages[o->head_idx];
1184 if (head == o->df_conflict_entry) {
1185 df_conflict_head = 1;
1186 head = NULL;
1189 if (remote == o->df_conflict_entry) {
1190 df_conflict_remote = 1;
1191 remote = NULL;
1195 * First, if there's a #16 situation, note that to prevent #13
1196 * and #14.
1198 if (!same(remote, head)) {
1199 for (i = 1; i < o->head_idx; i++) {
1200 if (same(stages[i], head)) {
1201 head_match = i;
1203 if (same(stages[i], remote)) {
1204 remote_match = i;
1210 * We start with cases where the index is allowed to match
1211 * something other than the head: #14(ALT) and #2ALT, where it
1212 * is permitted to match the result instead.
1214 /* #14, #14ALT, #2ALT */
1215 if (remote && !df_conflict_head && head_match && !remote_match) {
1216 if (index && !same(index, remote) && !same(index, head))
1217 return o->gently ? -1 : reject_merge(index, o);
1218 return merged_entry(remote, index, o);
1221 * If we have an entry in the index cache, then we want to
1222 * make sure that it matches head.
1224 if (index && !same(index, head))
1225 return o->gently ? -1 : reject_merge(index, o);
1227 if (head) {
1228 /* #5ALT, #15 */
1229 if (same(head, remote))
1230 return merged_entry(head, index, o);
1231 /* #13, #3ALT */
1232 if (!df_conflict_remote && remote_match && !head_match)
1233 return merged_entry(head, index, o);
1236 /* #1 */
1237 if (!head && !remote && any_anc_missing)
1238 return 0;
1241 * Under the "aggressive" rule, we resolve mostly trivial
1242 * cases that we historically had git-merge-one-file resolve.
1244 if (o->aggressive) {
1245 int head_deleted = !head;
1246 int remote_deleted = !remote;
1247 struct cache_entry *ce = NULL;
1249 if (index)
1250 ce = index;
1251 else if (head)
1252 ce = head;
1253 else if (remote)
1254 ce = remote;
1255 else {
1256 for (i = 1; i < o->head_idx; i++) {
1257 if (stages[i] && stages[i] != o->df_conflict_entry) {
1258 ce = stages[i];
1259 break;
1265 * Deleted in both.
1266 * Deleted in one and unchanged in the other.
1268 if ((head_deleted && remote_deleted) ||
1269 (head_deleted && remote && remote_match) ||
1270 (remote_deleted && head && head_match)) {
1271 if (index)
1272 return deleted_entry(index, index, o);
1273 if (ce && !head_deleted) {
1274 if (verify_absent(ce, "removed", o))
1275 return -1;
1277 return 0;
1280 * Added in both, identically.
1282 if (no_anc_exists && head && remote && same(head, remote))
1283 return merged_entry(head, index, o);
1287 /* Below are "no merge" cases, which require that the index be
1288 * up-to-date to avoid the files getting overwritten with
1289 * conflict resolution files.
1291 if (index) {
1292 if (verify_uptodate(index, o))
1293 return -1;
1296 o->nontrivial_merge = 1;
1298 /* #2, #3, #4, #6, #7, #9, #10, #11. */
1299 count = 0;
1300 if (!head_match || !remote_match) {
1301 for (i = 1; i < o->head_idx; i++) {
1302 if (stages[i] && stages[i] != o->df_conflict_entry) {
1303 keep_entry(stages[i], o);
1304 count++;
1305 break;
1309 #if DBRT_DEBUG
1310 else {
1311 fprintf(stderr, "read-tree: warning #16 detected\n");
1312 show_stage_entry(stderr, "head ", stages[head_match]);
1313 show_stage_entry(stderr, "remote ", stages[remote_match]);
1315 #endif
1316 if (head) { count += keep_entry(head, o); }
1317 if (remote) { count += keep_entry(remote, o); }
1318 return count;
1322 * Two-way merge.
1324 * The rule is to "carry forward" what is in the index without losing
1325 * information across a "fast-forward", favoring a successful merge
1326 * over a merge failure when it makes sense. For details of the
1327 * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
1330 int twoway_merge(struct cache_entry **src, struct unpack_trees_options *o)
1332 struct cache_entry *current = src[0];
1333 struct cache_entry *oldtree = src[1];
1334 struct cache_entry *newtree = src[2];
1336 if (o->merge_size != 2)
1337 return error("Cannot do a twoway merge of %d trees",
1338 o->merge_size);
1340 if (oldtree == o->df_conflict_entry)
1341 oldtree = NULL;
1342 if (newtree == o->df_conflict_entry)
1343 newtree = NULL;
1345 if (current) {
1346 if ((!oldtree && !newtree) || /* 4 and 5 */
1347 (!oldtree && newtree &&
1348 same(current, newtree)) || /* 6 and 7 */
1349 (oldtree && newtree &&
1350 same(oldtree, newtree)) || /* 14 and 15 */
1351 (oldtree && newtree &&
1352 !same(oldtree, newtree) && /* 18 and 19 */
1353 same(current, newtree))) {
1354 return keep_entry(current, o);
1356 else if (oldtree && !newtree && same(current, oldtree)) {
1357 /* 10 or 11 */
1358 return deleted_entry(oldtree, current, o);
1360 else if (oldtree && newtree &&
1361 same(current, oldtree) && !same(current, newtree)) {
1362 /* 20 or 21 */
1363 return merged_entry(newtree, current, o);
1365 else {
1366 /* all other failures */
1367 if (oldtree)
1368 return o->gently ? -1 : reject_merge(oldtree, o);
1369 if (current)
1370 return o->gently ? -1 : reject_merge(current, o);
1371 if (newtree)
1372 return o->gently ? -1 : reject_merge(newtree, o);
1373 return -1;
1376 else if (newtree) {
1377 if (oldtree && !o->initial_checkout) {
1379 * deletion of the path was staged;
1381 if (same(oldtree, newtree))
1382 return 1;
1383 return reject_merge(oldtree, o);
1385 return merged_entry(newtree, current, o);
1387 return deleted_entry(oldtree, current, o);
1391 * Bind merge.
1393 * Keep the index entries at stage0, collapse stage1 but make sure
1394 * stage0 does not have anything there.
1396 int bind_merge(struct cache_entry **src,
1397 struct unpack_trees_options *o)
1399 struct cache_entry *old = src[0];
1400 struct cache_entry *a = src[1];
1402 if (o->merge_size != 1)
1403 return error("Cannot do a bind merge of %d trees\n",
1404 o->merge_size);
1405 if (a && old)
1406 return o->gently ? -1 :
1407 error(ERRORMSG(o, bind_overlap), a->name, old->name);
1408 if (!a)
1409 return keep_entry(old, o);
1410 else
1411 return merged_entry(a, NULL, o);
1415 * One-way merge.
1417 * The rule is:
1418 * - take the stat information from stage0, take the data from stage1
1420 int oneway_merge(struct cache_entry **src, struct unpack_trees_options *o)
1422 struct cache_entry *old = src[0];
1423 struct cache_entry *a = src[1];
1425 if (o->merge_size != 1)
1426 return error("Cannot do a oneway merge of %d trees",
1427 o->merge_size);
1429 if (!a || a == o->df_conflict_entry)
1430 return deleted_entry(old, old, o);
1432 if (old && same(old, a)) {
1433 int update = 0;
1434 if (o->reset && !ce_uptodate(old) && !ce_skip_worktree(old)) {
1435 struct stat st;
1436 if (lstat(old->name, &st) ||
1437 ie_match_stat(o->src_index, old, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE))
1438 update |= CE_UPDATE;
1440 add_entry(o, old, update, 0);
1441 return 0;
1443 return merged_entry(a, old, o);