Merge branch 'jn/document-rebase-i-p-limitation' into maint
[git/jrn.git] / unpack-trees.c
blob490cd5f6f4779cbff68405722b98e522cbeb3cde
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] = { ce, NULL, };
283 int ret;
285 mark_ce_used(ce, o);
286 if (ce_stage(ce)) {
287 if (o->skip_unmerged) {
288 add_entry(o, ce, 0, 0);
289 return 0;
292 ret = call_unpack_fn(src, o);
293 if (ce_stage(ce))
294 mark_ce_used_same_name(ce, o);
295 return ret;
298 static int find_cache_pos(struct traverse_info *, const struct name_entry *);
300 static void restore_cache_bottom(struct traverse_info *info, int bottom)
302 struct unpack_trees_options *o = info->data;
304 if (o->diff_index_cached)
305 return;
306 o->cache_bottom = bottom;
309 static int switch_cache_bottom(struct traverse_info *info)
311 struct unpack_trees_options *o = info->data;
312 int ret, pos;
314 if (o->diff_index_cached)
315 return 0;
316 ret = o->cache_bottom;
317 pos = find_cache_pos(info->prev, &info->name);
319 if (pos < -1)
320 o->cache_bottom = -2 - pos;
321 else if (pos < 0)
322 o->cache_bottom = o->src_index->cache_nr;
323 return ret;
326 static int traverse_trees_recursive(int n, unsigned long dirmask, unsigned long df_conflicts, struct name_entry *names, struct traverse_info *info)
328 int i, ret, bottom;
329 struct tree_desc t[MAX_UNPACK_TREES];
330 struct traverse_info newinfo;
331 struct name_entry *p;
333 p = names;
334 while (!p->mode)
335 p++;
337 newinfo = *info;
338 newinfo.prev = info;
339 newinfo.name = *p;
340 newinfo.pathlen += tree_entry_len(p->path, p->sha1) + 1;
341 newinfo.conflicts |= df_conflicts;
343 for (i = 0; i < n; i++, dirmask >>= 1) {
344 const unsigned char *sha1 = NULL;
345 if (dirmask & 1)
346 sha1 = names[i].sha1;
347 fill_tree_descriptor(t+i, sha1);
350 bottom = switch_cache_bottom(&newinfo);
351 ret = traverse_trees(n, t, &newinfo);
352 restore_cache_bottom(&newinfo, bottom);
353 return ret;
357 * Compare the traverse-path to the cache entry without actually
358 * having to generate the textual representation of the traverse
359 * path.
361 * NOTE! This *only* compares up to the size of the traverse path
362 * itself - the caller needs to do the final check for the cache
363 * entry having more data at the end!
365 static int do_compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
367 int len, pathlen, ce_len;
368 const char *ce_name;
370 if (info->prev) {
371 int cmp = do_compare_entry(ce, info->prev, &info->name);
372 if (cmp)
373 return cmp;
375 pathlen = info->pathlen;
376 ce_len = ce_namelen(ce);
378 /* If ce_len < pathlen then we must have previously hit "name == directory" entry */
379 if (ce_len < pathlen)
380 return -1;
382 ce_len -= pathlen;
383 ce_name = ce->name + pathlen;
385 len = tree_entry_len(n->path, n->sha1);
386 return df_name_compare(ce_name, ce_len, S_IFREG, n->path, len, n->mode);
389 static int compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
391 int cmp = do_compare_entry(ce, info, n);
392 if (cmp)
393 return cmp;
396 * Even if the beginning compared identically, the ce should
397 * compare as bigger than a directory leading up to it!
399 return ce_namelen(ce) > traverse_path_len(info, n);
402 static int ce_in_traverse_path(const struct cache_entry *ce,
403 const struct traverse_info *info)
405 if (!info->prev)
406 return 1;
407 if (do_compare_entry(ce, info->prev, &info->name))
408 return 0;
410 * If ce (blob) is the same name as the path (which is a tree
411 * we will be descending into), it won't be inside it.
413 return (info->pathlen < ce_namelen(ce));
416 static struct cache_entry *create_ce_entry(const struct traverse_info *info, const struct name_entry *n, int stage)
418 int len = traverse_path_len(info, n);
419 struct cache_entry *ce = xcalloc(1, cache_entry_size(len));
421 ce->ce_mode = create_ce_mode(n->mode);
422 ce->ce_flags = create_ce_flags(len, stage);
423 hashcpy(ce->sha1, n->sha1);
424 make_traverse_path(ce->name, info, n);
426 return ce;
429 static int unpack_nondirectories(int n, unsigned long mask,
430 unsigned long dirmask,
431 struct cache_entry **src,
432 const struct name_entry *names,
433 const struct traverse_info *info)
435 int i;
436 struct unpack_trees_options *o = info->data;
437 unsigned long conflicts;
439 /* Do we have *only* directories? Nothing to do */
440 if (mask == dirmask && !src[0])
441 return 0;
443 conflicts = info->conflicts;
444 if (o->merge)
445 conflicts >>= 1;
446 conflicts |= dirmask;
449 * Ok, we've filled in up to any potential index entry in src[0],
450 * now do the rest.
452 for (i = 0; i < n; i++) {
453 int stage;
454 unsigned int bit = 1ul << i;
455 if (conflicts & bit) {
456 src[i + o->merge] = o->df_conflict_entry;
457 continue;
459 if (!(mask & bit))
460 continue;
461 if (!o->merge)
462 stage = 0;
463 else if (i + 1 < o->head_idx)
464 stage = 1;
465 else if (i + 1 > o->head_idx)
466 stage = 3;
467 else
468 stage = 2;
469 src[i + o->merge] = create_ce_entry(info, names + i, stage);
472 if (o->merge)
473 return call_unpack_fn(src, o);
475 for (i = 0; i < n; i++)
476 if (src[i] && src[i] != o->df_conflict_entry)
477 add_entry(o, src[i], 0, 0);
478 return 0;
481 static int unpack_failed(struct unpack_trees_options *o, const char *message)
483 discard_index(&o->result);
484 if (!o->gently) {
485 if (message)
486 return error("%s", message);
487 return -1;
489 return -1;
492 /* NEEDSWORK: give this a better name and share with tree-walk.c */
493 static int name_compare(const char *a, int a_len,
494 const char *b, int b_len)
496 int len = (a_len < b_len) ? a_len : b_len;
497 int cmp = memcmp(a, b, len);
498 if (cmp)
499 return cmp;
500 return (a_len - b_len);
504 * The tree traversal is looking at name p. If we have a matching entry,
505 * return it. If name p is a directory in the index, do not return
506 * anything, as we will want to match it when the traversal descends into
507 * the directory.
509 static int find_cache_pos(struct traverse_info *info,
510 const struct name_entry *p)
512 int pos;
513 struct unpack_trees_options *o = info->data;
514 struct index_state *index = o->src_index;
515 int pfxlen = info->pathlen;
516 int p_len = tree_entry_len(p->path, p->sha1);
518 for (pos = o->cache_bottom; pos < index->cache_nr; pos++) {
519 struct cache_entry *ce = index->cache[pos];
520 const char *ce_name, *ce_slash;
521 int cmp, ce_len;
523 if (!ce_in_traverse_path(ce, info))
524 continue;
525 if (ce->ce_flags & CE_UNPACKED)
526 continue;
527 ce_name = ce->name + pfxlen;
528 ce_slash = strchr(ce_name, '/');
529 if (ce_slash)
530 ce_len = ce_slash - ce_name;
531 else
532 ce_len = ce_namelen(ce) - pfxlen;
533 cmp = name_compare(p->path, p_len, ce_name, ce_len);
535 * Exact match; if we have a directory we need to
536 * delay returning it.
538 if (!cmp)
539 return ce_slash ? -2 - pos : pos;
540 if (0 < cmp)
541 continue; /* keep looking */
543 * ce_name sorts after p->path; could it be that we
544 * have files under p->path directory in the index?
545 * E.g. ce_name == "t-i", and p->path == "t"; we may
546 * have "t/a" in the index.
548 if (p_len < ce_len && !memcmp(ce_name, p->path, p_len) &&
549 ce_name[p_len] < '/')
550 continue; /* keep looking */
551 break;
553 return -1;
556 static struct cache_entry *find_cache_entry(struct traverse_info *info,
557 const struct name_entry *p)
559 int pos = find_cache_pos(info, p);
560 struct unpack_trees_options *o = info->data;
562 if (0 <= pos)
563 return o->src_index->cache[pos];
564 else
565 return NULL;
568 static void debug_path(struct traverse_info *info)
570 if (info->prev) {
571 debug_path(info->prev);
572 if (*info->prev->name.path)
573 putchar('/');
575 printf("%s", info->name.path);
578 static void debug_name_entry(int i, struct name_entry *n)
580 printf("ent#%d %06o %s\n", i,
581 n->path ? n->mode : 0,
582 n->path ? n->path : "(missing)");
585 static void debug_unpack_callback(int n,
586 unsigned long mask,
587 unsigned long dirmask,
588 struct name_entry *names,
589 struct traverse_info *info)
591 int i;
592 printf("* unpack mask %lu, dirmask %lu, cnt %d ",
593 mask, dirmask, n);
594 debug_path(info);
595 putchar('\n');
596 for (i = 0; i < n; i++)
597 debug_name_entry(i, names + i);
600 static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *names, struct traverse_info *info)
602 struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
603 struct unpack_trees_options *o = info->data;
604 const struct name_entry *p = names;
606 /* Find first entry with a real name (we could use "mask" too) */
607 while (!p->mode)
608 p++;
610 if (o->debug_unpack)
611 debug_unpack_callback(n, mask, dirmask, names, info);
613 /* Are we supposed to look at the index too? */
614 if (o->merge) {
615 while (1) {
616 int cmp;
617 struct cache_entry *ce;
619 if (o->diff_index_cached)
620 ce = next_cache_entry(o);
621 else
622 ce = find_cache_entry(info, p);
624 if (!ce)
625 break;
626 cmp = compare_entry(ce, info, p);
627 if (cmp < 0) {
628 if (unpack_index_entry(ce, o) < 0)
629 return unpack_failed(o, NULL);
630 continue;
632 if (!cmp) {
633 if (ce_stage(ce)) {
635 * If we skip unmerged index
636 * entries, we'll skip this
637 * entry *and* the tree
638 * entries associated with it!
640 if (o->skip_unmerged) {
641 add_same_unmerged(ce, o);
642 return mask;
645 src[0] = ce;
647 break;
651 if (unpack_nondirectories(n, mask, dirmask, src, names, info) < 0)
652 return -1;
654 if (src[0]) {
655 if (ce_stage(src[0]))
656 mark_ce_used_same_name(src[0], o);
657 else
658 mark_ce_used(src[0], o);
661 /* Now handle any directories.. */
662 if (dirmask) {
663 unsigned long conflicts = mask & ~dirmask;
664 if (o->merge) {
665 conflicts <<= 1;
666 if (src[0])
667 conflicts |= 1;
670 /* special case: "diff-index --cached" looking at a tree */
671 if (o->diff_index_cached &&
672 n == 1 && dirmask == 1 && S_ISDIR(names->mode)) {
673 int matches;
674 matches = cache_tree_matches_traversal(o->src_index->cache_tree,
675 names, info);
677 * Everything under the name matches; skip the
678 * entire hierarchy. diff_index_cached codepath
679 * special cases D/F conflicts in such a way that
680 * it does not do any look-ahead, so this is safe.
682 if (matches) {
683 o->cache_bottom += matches;
684 return mask;
688 if (traverse_trees_recursive(n, dirmask, conflicts,
689 names, info) < 0)
690 return -1;
691 return mask;
694 return mask;
698 * N-way merge "len" trees. Returns 0 on success, -1 on failure to manipulate the
699 * resulting index, -2 on failure to reflect the changes to the work tree.
701 int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o)
703 int i, ret;
704 static struct cache_entry *dfc;
705 struct exclude_list el;
707 if (len > MAX_UNPACK_TREES)
708 die("unpack_trees takes at most %d trees", MAX_UNPACK_TREES);
709 memset(&state, 0, sizeof(state));
710 state.base_dir = "";
711 state.force = 1;
712 state.quiet = 1;
713 state.refresh_cache = 1;
715 memset(&el, 0, sizeof(el));
716 if (!core_apply_sparse_checkout || !o->update)
717 o->skip_sparse_checkout = 1;
718 if (!o->skip_sparse_checkout) {
719 if (add_excludes_from_file_to_list(git_path("info/sparse-checkout"), "", 0, NULL, &el, 0) < 0)
720 o->skip_sparse_checkout = 1;
721 else
722 o->el = &el;
725 memset(&o->result, 0, sizeof(o->result));
726 o->result.initialized = 1;
727 o->result.timestamp.sec = o->src_index->timestamp.sec;
728 o->result.timestamp.nsec = o->src_index->timestamp.nsec;
729 o->merge_size = len;
730 mark_all_ce_unused(o->src_index);
732 if (!dfc)
733 dfc = xcalloc(1, cache_entry_size(0));
734 o->df_conflict_entry = dfc;
736 if (len) {
737 const char *prefix = o->prefix ? o->prefix : "";
738 struct traverse_info info;
740 setup_traverse_info(&info, prefix);
741 info.fn = unpack_callback;
742 info.data = o;
744 if (o->prefix) {
746 * Unpack existing index entries that sort before the
747 * prefix the tree is spliced into. Note that o->merge
748 * is always true in this case.
750 while (1) {
751 struct cache_entry *ce = next_cache_entry(o);
752 if (!ce)
753 break;
754 if (ce_in_traverse_path(ce, &info))
755 break;
756 if (unpack_index_entry(ce, o) < 0)
757 goto return_failed;
761 if (traverse_trees(len, t, &info) < 0)
762 goto return_failed;
765 /* Any left-over entries in the index? */
766 if (o->merge) {
767 while (1) {
768 struct cache_entry *ce = next_cache_entry(o);
769 if (!ce)
770 break;
771 if (unpack_index_entry(ce, o) < 0)
772 goto return_failed;
775 mark_all_ce_unused(o->src_index);
777 if (o->trivial_merges_only && o->nontrivial_merge) {
778 ret = unpack_failed(o, "Merge requires file-level merging");
779 goto done;
782 if (!o->skip_sparse_checkout) {
783 int empty_worktree = 1;
784 for (i = 0;i < o->result.cache_nr;i++) {
785 struct cache_entry *ce = o->result.cache[i];
787 if (apply_sparse_checkout(ce, o)) {
788 ret = -1;
789 goto done;
792 * Merge strategies may set CE_UPDATE|CE_REMOVE outside checkout
793 * area as a result of ce_skip_worktree() shortcuts in
794 * verify_absent() and verify_uptodate(). Clear them.
796 if (ce_skip_worktree(ce))
797 ce->ce_flags &= ~(CE_UPDATE | CE_REMOVE);
798 else
799 empty_worktree = 0;
802 if (o->result.cache_nr && empty_worktree) {
803 ret = unpack_failed(o, "Sparse checkout leaves no entry on working directory");
804 goto done;
808 o->src_index = NULL;
809 ret = check_updates(o) ? (-2) : 0;
810 if (o->dst_index)
811 *o->dst_index = o->result;
813 done:
814 for (i = 0;i < el.nr;i++)
815 free(el.excludes[i]);
816 if (el.excludes)
817 free(el.excludes);
819 return ret;
821 return_failed:
822 mark_all_ce_unused(o->src_index);
823 ret = unpack_failed(o, NULL);
824 goto done;
827 /* Here come the merge functions */
829 static int reject_merge(struct cache_entry *ce, struct unpack_trees_options *o)
831 return error(ERRORMSG(o, would_overwrite), ce->name);
834 static int same(struct cache_entry *a, struct cache_entry *b)
836 if (!!a != !!b)
837 return 0;
838 if (!a && !b)
839 return 1;
840 if ((a->ce_flags | b->ce_flags) & CE_CONFLICTED)
841 return 0;
842 return a->ce_mode == b->ce_mode &&
843 !hashcmp(a->sha1, b->sha1);
848 * When a CE gets turned into an unmerged entry, we
849 * want it to be up-to-date
851 static int verify_uptodate_1(struct cache_entry *ce,
852 struct unpack_trees_options *o,
853 const char *error_msg)
855 struct stat st;
857 if (o->index_only || (!((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce)) && (o->reset || ce_uptodate(ce))))
858 return 0;
860 if (!lstat(ce->name, &st)) {
861 unsigned changed = ie_match_stat(o->src_index, ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
862 if (!changed)
863 return 0;
865 * NEEDSWORK: the current default policy is to allow
866 * submodule to be out of sync wrt the supermodule
867 * index. This needs to be tightened later for
868 * submodules that are marked to be automatically
869 * checked out.
871 if (S_ISGITLINK(ce->ce_mode))
872 return 0;
873 errno = 0;
875 if (errno == ENOENT)
876 return 0;
877 return o->gently ? -1 :
878 error(error_msg, ce->name);
881 static int verify_uptodate(struct cache_entry *ce,
882 struct unpack_trees_options *o)
884 if (!o->skip_sparse_checkout && will_have_skip_worktree(ce, o))
885 return 0;
886 return verify_uptodate_1(ce, o, ERRORMSG(o, not_uptodate_file));
889 static int verify_uptodate_sparse(struct cache_entry *ce,
890 struct unpack_trees_options *o)
892 return verify_uptodate_1(ce, o, ERRORMSG(o, sparse_not_uptodate_file));
895 static void invalidate_ce_path(struct cache_entry *ce, struct unpack_trees_options *o)
897 if (ce)
898 cache_tree_invalidate_path(o->src_index->cache_tree, ce->name);
902 * Check that checking out ce->sha1 in subdir ce->name is not
903 * going to overwrite any working files.
905 * Currently, git does not checkout subprojects during a superproject
906 * checkout, so it is not going to overwrite anything.
908 static int verify_clean_submodule(struct cache_entry *ce, const char *action,
909 struct unpack_trees_options *o)
911 return 0;
914 static int verify_clean_subdirectory(struct cache_entry *ce, const char *action,
915 struct unpack_trees_options *o)
918 * we are about to extract "ce->name"; we would not want to lose
919 * anything in the existing directory there.
921 int namelen;
922 int i;
923 struct dir_struct d;
924 char *pathbuf;
925 int cnt = 0;
926 unsigned char sha1[20];
928 if (S_ISGITLINK(ce->ce_mode) &&
929 resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) {
930 /* If we are not going to update the submodule, then
931 * we don't care.
933 if (!hashcmp(sha1, ce->sha1))
934 return 0;
935 return verify_clean_submodule(ce, action, o);
939 * First let's make sure we do not have a local modification
940 * in that directory.
942 namelen = strlen(ce->name);
943 for (i = locate_in_src_index(ce, o);
944 i < o->src_index->cache_nr;
945 i++) {
946 struct cache_entry *ce2 = o->src_index->cache[i];
947 int len = ce_namelen(ce2);
948 if (len < namelen ||
949 strncmp(ce->name, ce2->name, namelen) ||
950 ce2->name[namelen] != '/')
951 break;
953 * ce2->name is an entry in the subdirectory to be
954 * removed.
956 if (!ce_stage(ce2)) {
957 if (verify_uptodate(ce2, o))
958 return -1;
959 add_entry(o, ce2, CE_REMOVE, 0);
960 mark_ce_used(ce2, o);
962 cnt++;
966 * Then we need to make sure that we do not lose a locally
967 * present file that is not ignored.
969 pathbuf = xmalloc(namelen + 2);
970 memcpy(pathbuf, ce->name, namelen);
971 strcpy(pathbuf+namelen, "/");
973 memset(&d, 0, sizeof(d));
974 if (o->dir)
975 d.exclude_per_dir = o->dir->exclude_per_dir;
976 i = read_directory(&d, pathbuf, namelen+1, NULL);
977 if (i)
978 return o->gently ? -1 :
979 error(ERRORMSG(o, not_uptodate_dir), ce->name);
980 free(pathbuf);
981 return cnt;
985 * This gets called when there was no index entry for the tree entry 'dst',
986 * but we found a file in the working tree that 'lstat()' said was fine,
987 * and we're on a case-insensitive filesystem.
989 * See if we can find a case-insensitive match in the index that also
990 * matches the stat information, and assume it's that other file!
992 static int icase_exists(struct unpack_trees_options *o, struct cache_entry *dst, struct stat *st)
994 struct cache_entry *src;
996 src = index_name_exists(o->src_index, dst->name, ce_namelen(dst), 1);
997 return src && !ie_match_stat(o->src_index, src, st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
1001 * We do not want to remove or overwrite a working tree file that
1002 * is not tracked, unless it is ignored.
1004 static int verify_absent_1(struct cache_entry *ce, const char *action,
1005 struct unpack_trees_options *o,
1006 const char *error_msg)
1008 struct stat st;
1010 if (o->index_only || o->reset || !o->update)
1011 return 0;
1013 if (has_symlink_or_noent_leading_path(ce->name, ce_namelen(ce)))
1014 return 0;
1016 if (!lstat(ce->name, &st)) {
1017 int dtype = ce_to_dtype(ce);
1018 struct cache_entry *result;
1021 * It may be that the 'lstat()' succeeded even though
1022 * target 'ce' was absent, because there is an old
1023 * entry that is different only in case..
1025 * Ignore that lstat() if it matches.
1027 if (ignore_case && icase_exists(o, ce, &st))
1028 return 0;
1030 if (o->dir && excluded(o->dir, ce->name, &dtype))
1032 * ce->name is explicitly excluded, so it is Ok to
1033 * overwrite it.
1035 return 0;
1036 if (S_ISDIR(st.st_mode)) {
1038 * We are checking out path "foo" and
1039 * found "foo/." in the working tree.
1040 * This is tricky -- if we have modified
1041 * files that are in "foo/" we would lose
1042 * them.
1044 if (verify_clean_subdirectory(ce, action, o) < 0)
1045 return -1;
1046 return 0;
1050 * The previous round may already have decided to
1051 * delete this path, which is in a subdirectory that
1052 * is being replaced with a blob.
1054 result = index_name_exists(&o->result, ce->name, ce_namelen(ce), 0);
1055 if (result) {
1056 if (result->ce_flags & CE_REMOVE)
1057 return 0;
1060 return o->gently ? -1 :
1061 error(ERRORMSG(o, would_lose_untracked), ce->name, action);
1063 return 0;
1065 static int verify_absent(struct cache_entry *ce, const char *action,
1066 struct unpack_trees_options *o)
1068 if (!o->skip_sparse_checkout && will_have_skip_worktree(ce, o))
1069 return 0;
1070 return verify_absent_1(ce, action, o, ERRORMSG(o, would_lose_untracked));
1073 static int verify_absent_sparse(struct cache_entry *ce, const char *action,
1074 struct unpack_trees_options *o)
1076 return verify_absent_1(ce, action, o, ERRORMSG(o, would_lose_orphaned));
1079 static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
1080 struct unpack_trees_options *o)
1082 int update = CE_UPDATE;
1084 if (!old) {
1085 if (verify_absent(merge, "overwritten", o))
1086 return -1;
1087 invalidate_ce_path(merge, o);
1088 } else if (!(old->ce_flags & CE_CONFLICTED)) {
1090 * See if we can re-use the old CE directly?
1091 * That way we get the uptodate stat info.
1093 * This also removes the UPDATE flag on a match; otherwise
1094 * we will end up overwriting local changes in the work tree.
1096 if (same(old, merge)) {
1097 copy_cache_entry(merge, old);
1098 update = 0;
1099 } else {
1100 if (verify_uptodate(old, o))
1101 return -1;
1102 if (ce_skip_worktree(old))
1103 update |= CE_SKIP_WORKTREE;
1104 invalidate_ce_path(old, o);
1106 } else {
1108 * Previously unmerged entry left as an existence
1109 * marker by read_index_unmerged();
1111 invalidate_ce_path(old, o);
1114 add_entry(o, merge, update, CE_STAGEMASK);
1115 return 1;
1118 static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
1119 struct unpack_trees_options *o)
1121 /* Did it exist in the index? */
1122 if (!old) {
1123 if (verify_absent(ce, "removed", o))
1124 return -1;
1125 return 0;
1127 if (!(old->ce_flags & CE_CONFLICTED) && verify_uptodate(old, o))
1128 return -1;
1129 add_entry(o, ce, CE_REMOVE, 0);
1130 invalidate_ce_path(ce, o);
1131 return 1;
1134 static int keep_entry(struct cache_entry *ce, struct unpack_trees_options *o)
1136 add_entry(o, ce, 0, 0);
1137 return 1;
1140 #if DBRT_DEBUG
1141 static void show_stage_entry(FILE *o,
1142 const char *label, const struct cache_entry *ce)
1144 if (!ce)
1145 fprintf(o, "%s (missing)\n", label);
1146 else
1147 fprintf(o, "%s%06o %s %d\t%s\n",
1148 label,
1149 ce->ce_mode,
1150 sha1_to_hex(ce->sha1),
1151 ce_stage(ce),
1152 ce->name);
1154 #endif
1156 int threeway_merge(struct cache_entry **stages, struct unpack_trees_options *o)
1158 struct cache_entry *index;
1159 struct cache_entry *head;
1160 struct cache_entry *remote = stages[o->head_idx + 1];
1161 int count;
1162 int head_match = 0;
1163 int remote_match = 0;
1165 int df_conflict_head = 0;
1166 int df_conflict_remote = 0;
1168 int any_anc_missing = 0;
1169 int no_anc_exists = 1;
1170 int i;
1172 for (i = 1; i < o->head_idx; i++) {
1173 if (!stages[i] || stages[i] == o->df_conflict_entry)
1174 any_anc_missing = 1;
1175 else
1176 no_anc_exists = 0;
1179 index = stages[0];
1180 head = stages[o->head_idx];
1182 if (head == o->df_conflict_entry) {
1183 df_conflict_head = 1;
1184 head = NULL;
1187 if (remote == o->df_conflict_entry) {
1188 df_conflict_remote = 1;
1189 remote = NULL;
1193 * First, if there's a #16 situation, note that to prevent #13
1194 * and #14.
1196 if (!same(remote, head)) {
1197 for (i = 1; i < o->head_idx; i++) {
1198 if (same(stages[i], head)) {
1199 head_match = i;
1201 if (same(stages[i], remote)) {
1202 remote_match = i;
1208 * We start with cases where the index is allowed to match
1209 * something other than the head: #14(ALT) and #2ALT, where it
1210 * is permitted to match the result instead.
1212 /* #14, #14ALT, #2ALT */
1213 if (remote && !df_conflict_head && head_match && !remote_match) {
1214 if (index && !same(index, remote) && !same(index, head))
1215 return o->gently ? -1 : reject_merge(index, o);
1216 return merged_entry(remote, index, o);
1219 * If we have an entry in the index cache, then we want to
1220 * make sure that it matches head.
1222 if (index && !same(index, head))
1223 return o->gently ? -1 : reject_merge(index, o);
1225 if (head) {
1226 /* #5ALT, #15 */
1227 if (same(head, remote))
1228 return merged_entry(head, index, o);
1229 /* #13, #3ALT */
1230 if (!df_conflict_remote && remote_match && !head_match)
1231 return merged_entry(head, index, o);
1234 /* #1 */
1235 if (!head && !remote && any_anc_missing)
1236 return 0;
1239 * Under the "aggressive" rule, we resolve mostly trivial
1240 * cases that we historically had git-merge-one-file resolve.
1242 if (o->aggressive) {
1243 int head_deleted = !head;
1244 int remote_deleted = !remote;
1245 struct cache_entry *ce = NULL;
1247 if (index)
1248 ce = index;
1249 else if (head)
1250 ce = head;
1251 else if (remote)
1252 ce = remote;
1253 else {
1254 for (i = 1; i < o->head_idx; i++) {
1255 if (stages[i] && stages[i] != o->df_conflict_entry) {
1256 ce = stages[i];
1257 break;
1263 * Deleted in both.
1264 * Deleted in one and unchanged in the other.
1266 if ((head_deleted && remote_deleted) ||
1267 (head_deleted && remote && remote_match) ||
1268 (remote_deleted && head && head_match)) {
1269 if (index)
1270 return deleted_entry(index, index, o);
1271 if (ce && !head_deleted) {
1272 if (verify_absent(ce, "removed", o))
1273 return -1;
1275 return 0;
1278 * Added in both, identically.
1280 if (no_anc_exists && head && remote && same(head, remote))
1281 return merged_entry(head, index, o);
1285 /* Below are "no merge" cases, which require that the index be
1286 * up-to-date to avoid the files getting overwritten with
1287 * conflict resolution files.
1289 if (index) {
1290 if (verify_uptodate(index, o))
1291 return -1;
1294 o->nontrivial_merge = 1;
1296 /* #2, #3, #4, #6, #7, #9, #10, #11. */
1297 count = 0;
1298 if (!head_match || !remote_match) {
1299 for (i = 1; i < o->head_idx; i++) {
1300 if (stages[i] && stages[i] != o->df_conflict_entry) {
1301 keep_entry(stages[i], o);
1302 count++;
1303 break;
1307 #if DBRT_DEBUG
1308 else {
1309 fprintf(stderr, "read-tree: warning #16 detected\n");
1310 show_stage_entry(stderr, "head ", stages[head_match]);
1311 show_stage_entry(stderr, "remote ", stages[remote_match]);
1313 #endif
1314 if (head) { count += keep_entry(head, o); }
1315 if (remote) { count += keep_entry(remote, o); }
1316 return count;
1320 * Two-way merge.
1322 * The rule is to "carry forward" what is in the index without losing
1323 * information across a "fast-forward", favoring a successful merge
1324 * over a merge failure when it makes sense. For details of the
1325 * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
1328 int twoway_merge(struct cache_entry **src, struct unpack_trees_options *o)
1330 struct cache_entry *current = src[0];
1331 struct cache_entry *oldtree = src[1];
1332 struct cache_entry *newtree = src[2];
1334 if (o->merge_size != 2)
1335 return error("Cannot do a twoway merge of %d trees",
1336 o->merge_size);
1338 if (oldtree == o->df_conflict_entry)
1339 oldtree = NULL;
1340 if (newtree == o->df_conflict_entry)
1341 newtree = NULL;
1343 if (current) {
1344 if ((!oldtree && !newtree) || /* 4 and 5 */
1345 (!oldtree && newtree &&
1346 same(current, newtree)) || /* 6 and 7 */
1347 (oldtree && newtree &&
1348 same(oldtree, newtree)) || /* 14 and 15 */
1349 (oldtree && newtree &&
1350 !same(oldtree, newtree) && /* 18 and 19 */
1351 same(current, newtree))) {
1352 return keep_entry(current, o);
1354 else if (oldtree && !newtree && same(current, oldtree)) {
1355 /* 10 or 11 */
1356 return deleted_entry(oldtree, current, o);
1358 else if (oldtree && newtree &&
1359 same(current, oldtree) && !same(current, newtree)) {
1360 /* 20 or 21 */
1361 return merged_entry(newtree, current, o);
1363 else {
1364 /* all other failures */
1365 if (oldtree)
1366 return o->gently ? -1 : reject_merge(oldtree, o);
1367 if (current)
1368 return o->gently ? -1 : reject_merge(current, o);
1369 if (newtree)
1370 return o->gently ? -1 : reject_merge(newtree, o);
1371 return -1;
1374 else if (newtree) {
1375 if (oldtree && !o->initial_checkout) {
1377 * deletion of the path was staged;
1379 if (same(oldtree, newtree))
1380 return 1;
1381 return reject_merge(oldtree, o);
1383 return merged_entry(newtree, current, o);
1385 return deleted_entry(oldtree, current, o);
1389 * Bind merge.
1391 * Keep the index entries at stage0, collapse stage1 but make sure
1392 * stage0 does not have anything there.
1394 int bind_merge(struct cache_entry **src,
1395 struct unpack_trees_options *o)
1397 struct cache_entry *old = src[0];
1398 struct cache_entry *a = src[1];
1400 if (o->merge_size != 1)
1401 return error("Cannot do a bind merge of %d trees\n",
1402 o->merge_size);
1403 if (a && old)
1404 return o->gently ? -1 :
1405 error(ERRORMSG(o, bind_overlap), a->name, old->name);
1406 if (!a)
1407 return keep_entry(old, o);
1408 else
1409 return merged_entry(a, NULL, o);
1413 * One-way merge.
1415 * The rule is:
1416 * - take the stat information from stage0, take the data from stage1
1418 int oneway_merge(struct cache_entry **src, struct unpack_trees_options *o)
1420 struct cache_entry *old = src[0];
1421 struct cache_entry *a = src[1];
1423 if (o->merge_size != 1)
1424 return error("Cannot do a oneway merge of %d trees",
1425 o->merge_size);
1427 if (!a || a == o->df_conflict_entry)
1428 return deleted_entry(old, old, o);
1430 if (old && same(old, a)) {
1431 int update = 0;
1432 if (o->reset && !ce_uptodate(old) && !ce_skip_worktree(old)) {
1433 struct stat st;
1434 if (lstat(old->name, &st) ||
1435 ie_match_stat(o->src_index, old, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE))
1436 update |= CE_UPDATE;
1438 add_entry(o, old, update, 0);
1439 return 0;
1441 return merged_entry(a, old, o);