gitweb: Add git_merge sub
[git/gsoc2010-gitweb.git] / merge-recursive.c
blob206c1036359ce7b1fc5a1f5734b2d0bc2a760d90
1 /*
2 * Recursive Merge algorithm stolen from git-merge-recursive.py by
3 * Fredrik Kuivinen.
4 * The thieves were Alex Riesen and Johannes Schindelin, in June/July 2006
5 */
6 #include "advice.h"
7 #include "cache.h"
8 #include "cache-tree.h"
9 #include "commit.h"
10 #include "blob.h"
11 #include "builtin.h"
12 #include "tree-walk.h"
13 #include "diff.h"
14 #include "diffcore.h"
15 #include "tag.h"
16 #include "unpack-trees.h"
17 #include "string-list.h"
18 #include "xdiff-interface.h"
19 #include "ll-merge.h"
20 #include "attr.h"
21 #include "merge-recursive.h"
22 #include "dir.h"
24 static struct tree *shift_tree_object(struct tree *one, struct tree *two,
25 const char *subtree_shift)
27 unsigned char shifted[20];
29 if (!*subtree_shift) {
30 shift_tree(one->object.sha1, two->object.sha1, shifted, 0);
31 } else {
32 shift_tree_by(one->object.sha1, two->object.sha1, shifted,
33 subtree_shift);
35 if (!hashcmp(two->object.sha1, shifted))
36 return two;
37 return lookup_tree(shifted);
41 * A virtual commit has (const char *)commit->util set to the name.
44 static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
46 struct commit *commit = xcalloc(1, sizeof(struct commit));
47 commit->tree = tree;
48 commit->util = (void*)comment;
49 /* avoid warnings */
50 commit->object.parsed = 1;
51 return commit;
55 * Since we use get_tree_entry(), which does not put the read object into
56 * the object pool, we cannot rely on a == b.
58 static int sha_eq(const unsigned char *a, const unsigned char *b)
60 if (!a && !b)
61 return 2;
62 return a && b && hashcmp(a, b) == 0;
66 * Since we want to write the index eventually, we cannot reuse the index
67 * for these (temporary) data.
69 struct stage_data
71 struct
73 unsigned mode;
74 unsigned char sha[20];
75 } stages[4];
76 unsigned processed:1;
79 static int show(struct merge_options *o, int v)
81 return (!o->call_depth && o->verbosity >= v) || o->verbosity >= 5;
84 static void flush_output(struct merge_options *o)
86 if (o->obuf.len) {
87 fputs(o->obuf.buf, stdout);
88 strbuf_reset(&o->obuf);
92 __attribute__((format (printf, 3, 4)))
93 static void output(struct merge_options *o, int v, const char *fmt, ...)
95 int len;
96 va_list ap;
98 if (!show(o, v))
99 return;
101 strbuf_grow(&o->obuf, o->call_depth * 2 + 2);
102 memset(o->obuf.buf + o->obuf.len, ' ', o->call_depth * 2);
103 strbuf_setlen(&o->obuf, o->obuf.len + o->call_depth * 2);
105 va_start(ap, fmt);
106 len = vsnprintf(o->obuf.buf + o->obuf.len, strbuf_avail(&o->obuf), fmt, ap);
107 va_end(ap);
109 if (len < 0)
110 len = 0;
111 if (len >= strbuf_avail(&o->obuf)) {
112 strbuf_grow(&o->obuf, len + 2);
113 va_start(ap, fmt);
114 len = vsnprintf(o->obuf.buf + o->obuf.len, strbuf_avail(&o->obuf), fmt, ap);
115 va_end(ap);
116 if (len >= strbuf_avail(&o->obuf)) {
117 die("this should not happen, your snprintf is broken");
120 strbuf_setlen(&o->obuf, o->obuf.len + len);
121 strbuf_add(&o->obuf, "\n", 1);
122 if (!o->buffer_output)
123 flush_output(o);
126 static void output_commit_title(struct merge_options *o, struct commit *commit)
128 int i;
129 flush_output(o);
130 for (i = o->call_depth; i--;)
131 fputs(" ", stdout);
132 if (commit->util)
133 printf("virtual %s\n", (char *)commit->util);
134 else {
135 printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
136 if (parse_commit(commit) != 0)
137 printf("(bad commit)\n");
138 else {
139 const char *s;
140 int len;
141 for (s = commit->buffer; *s; s++)
142 if (*s == '\n' && s[1] == '\n') {
143 s += 2;
144 break;
146 for (len = 0; s[len] && '\n' != s[len]; len++)
147 ; /* do nothing */
148 printf("%.*s\n", len, s);
153 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
154 const char *path, int stage, int refresh, int options)
156 struct cache_entry *ce;
157 ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
158 if (!ce)
159 return error("addinfo_cache failed for path '%s'", path);
160 return add_cache_entry(ce, options);
163 static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
165 parse_tree(tree);
166 init_tree_desc(desc, tree->buffer, tree->size);
169 static int git_merge_trees(int index_only,
170 struct tree *common,
171 struct tree *head,
172 struct tree *merge)
174 int rc;
175 struct tree_desc t[3];
176 struct unpack_trees_options opts;
178 memset(&opts, 0, sizeof(opts));
179 if (index_only)
180 opts.index_only = 1;
181 else
182 opts.update = 1;
183 opts.merge = 1;
184 opts.head_idx = 2;
185 opts.fn = threeway_merge;
186 opts.src_index = &the_index;
187 opts.dst_index = &the_index;
188 opts.msgs = get_porcelain_error_msgs();
190 init_tree_desc_from_tree(t+0, common);
191 init_tree_desc_from_tree(t+1, head);
192 init_tree_desc_from_tree(t+2, merge);
194 rc = unpack_trees(3, t, &opts);
195 cache_tree_free(&active_cache_tree);
196 return rc;
199 struct tree *write_tree_from_memory(struct merge_options *o)
201 struct tree *result = NULL;
203 if (unmerged_cache()) {
204 int i;
205 fprintf(stderr, "BUG: There are unmerged index entries:\n");
206 for (i = 0; i < active_nr; i++) {
207 struct cache_entry *ce = active_cache[i];
208 if (ce_stage(ce))
209 fprintf(stderr, "BUG: %d %.*s", ce_stage(ce),
210 (int)ce_namelen(ce), ce->name);
212 die("Bug in merge-recursive.c");
215 if (!active_cache_tree)
216 active_cache_tree = cache_tree();
218 if (!cache_tree_fully_valid(active_cache_tree) &&
219 cache_tree_update(active_cache_tree,
220 active_cache, active_nr, 0, 0) < 0)
221 die("error building trees");
223 result = lookup_tree(active_cache_tree->sha1);
225 return result;
228 static int save_files_dirs(const unsigned char *sha1,
229 const char *base, int baselen, const char *path,
230 unsigned int mode, int stage, void *context)
232 int len = strlen(path);
233 char *newpath = xmalloc(baselen + len + 1);
234 struct merge_options *o = context;
236 memcpy(newpath, base, baselen);
237 memcpy(newpath + baselen, path, len);
238 newpath[baselen + len] = '\0';
240 if (S_ISDIR(mode))
241 string_list_insert(newpath, &o->current_directory_set);
242 else
243 string_list_insert(newpath, &o->current_file_set);
244 free(newpath);
246 return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
249 static int get_files_dirs(struct merge_options *o, struct tree *tree)
251 int n;
252 if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs, o))
253 return 0;
254 n = o->current_file_set.nr + o->current_directory_set.nr;
255 return n;
259 * Returns an index_entry instance which doesn't have to correspond to
260 * a real cache entry in Git's index.
262 static struct stage_data *insert_stage_data(const char *path,
263 struct tree *o, struct tree *a, struct tree *b,
264 struct string_list *entries)
266 struct string_list_item *item;
267 struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
268 get_tree_entry(o->object.sha1, path,
269 e->stages[1].sha, &e->stages[1].mode);
270 get_tree_entry(a->object.sha1, path,
271 e->stages[2].sha, &e->stages[2].mode);
272 get_tree_entry(b->object.sha1, path,
273 e->stages[3].sha, &e->stages[3].mode);
274 item = string_list_insert(path, entries);
275 item->util = e;
276 return e;
280 * Create a dictionary mapping file names to stage_data objects. The
281 * dictionary contains one entry for every path with a non-zero stage entry.
283 static struct string_list *get_unmerged(void)
285 struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
286 int i;
288 unmerged->strdup_strings = 1;
290 for (i = 0; i < active_nr; i++) {
291 struct string_list_item *item;
292 struct stage_data *e;
293 struct cache_entry *ce = active_cache[i];
294 if (!ce_stage(ce))
295 continue;
297 item = string_list_lookup(ce->name, unmerged);
298 if (!item) {
299 item = string_list_insert(ce->name, unmerged);
300 item->util = xcalloc(1, sizeof(struct stage_data));
302 e = item->util;
303 e->stages[ce_stage(ce)].mode = ce->ce_mode;
304 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
307 return unmerged;
310 struct rename
312 struct diff_filepair *pair;
313 struct stage_data *src_entry;
314 struct stage_data *dst_entry;
315 unsigned processed:1;
319 * Get information of all renames which occurred between 'o_tree' and
320 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
321 * 'b_tree') to be able to associate the correct cache entries with
322 * the rename information. 'tree' is always equal to either a_tree or b_tree.
324 static struct string_list *get_renames(struct merge_options *o,
325 struct tree *tree,
326 struct tree *o_tree,
327 struct tree *a_tree,
328 struct tree *b_tree,
329 struct string_list *entries)
331 int i;
332 struct string_list *renames;
333 struct diff_options opts;
335 renames = xcalloc(1, sizeof(struct string_list));
336 diff_setup(&opts);
337 DIFF_OPT_SET(&opts, RECURSIVE);
338 opts.detect_rename = DIFF_DETECT_RENAME;
339 opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
340 o->diff_rename_limit >= 0 ? o->diff_rename_limit :
341 500;
342 opts.warn_on_too_large_rename = 1;
343 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
344 if (diff_setup_done(&opts) < 0)
345 die("diff setup failed");
346 diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
347 diffcore_std(&opts);
348 for (i = 0; i < diff_queued_diff.nr; ++i) {
349 struct string_list_item *item;
350 struct rename *re;
351 struct diff_filepair *pair = diff_queued_diff.queue[i];
352 if (pair->status != 'R') {
353 diff_free_filepair(pair);
354 continue;
356 re = xmalloc(sizeof(*re));
357 re->processed = 0;
358 re->pair = pair;
359 item = string_list_lookup(re->pair->one->path, entries);
360 if (!item)
361 re->src_entry = insert_stage_data(re->pair->one->path,
362 o_tree, a_tree, b_tree, entries);
363 else
364 re->src_entry = item->util;
366 item = string_list_lookup(re->pair->two->path, entries);
367 if (!item)
368 re->dst_entry = insert_stage_data(re->pair->two->path,
369 o_tree, a_tree, b_tree, entries);
370 else
371 re->dst_entry = item->util;
372 item = string_list_insert(pair->one->path, renames);
373 item->util = re;
375 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
376 diff_queued_diff.nr = 0;
377 diff_flush(&opts);
378 return renames;
381 static int update_stages(const char *path, struct diff_filespec *o,
382 struct diff_filespec *a, struct diff_filespec *b,
383 int clear)
385 int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
386 if (clear)
387 if (remove_file_from_cache(path))
388 return -1;
389 if (o)
390 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
391 return -1;
392 if (a)
393 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
394 return -1;
395 if (b)
396 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
397 return -1;
398 return 0;
401 static int remove_file(struct merge_options *o, int clean,
402 const char *path, int no_wd)
404 int update_cache = o->call_depth || clean;
405 int update_working_directory = !o->call_depth && !no_wd;
407 if (update_cache) {
408 if (remove_file_from_cache(path))
409 return -1;
411 if (update_working_directory) {
412 if (remove_path(path))
413 return -1;
415 return 0;
418 static char *unique_path(struct merge_options *o, const char *path, const char *branch)
420 char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
421 int suffix = 0;
422 struct stat st;
423 char *p = newpath + strlen(path);
424 strcpy(newpath, path);
425 *(p++) = '~';
426 strcpy(p, branch);
427 for (; *p; ++p)
428 if ('/' == *p)
429 *p = '_';
430 while (string_list_has_string(&o->current_file_set, newpath) ||
431 string_list_has_string(&o->current_directory_set, newpath) ||
432 lstat(newpath, &st) == 0)
433 sprintf(p, "_%d", suffix++);
435 string_list_insert(newpath, &o->current_file_set);
436 return newpath;
439 static void flush_buffer(int fd, const char *buf, unsigned long size)
441 while (size > 0) {
442 long ret = write_in_full(fd, buf, size);
443 if (ret < 0) {
444 /* Ignore epipe */
445 if (errno == EPIPE)
446 break;
447 die_errno("merge-recursive");
448 } else if (!ret) {
449 die("merge-recursive: disk full?");
451 size -= ret;
452 buf += ret;
456 static int would_lose_untracked(const char *path)
458 int pos = cache_name_pos(path, strlen(path));
460 if (pos < 0)
461 pos = -1 - pos;
462 while (pos < active_nr &&
463 !strcmp(path, active_cache[pos]->name)) {
465 * If stage #0, it is definitely tracked.
466 * If it has stage #2 then it was tracked
467 * before this merge started. All other
468 * cases the path was not tracked.
470 switch (ce_stage(active_cache[pos])) {
471 case 0:
472 case 2:
473 return 0;
475 pos++;
477 return file_exists(path);
480 static int make_room_for_path(const char *path)
482 int status;
483 const char *msg = "failed to create path '%s'%s";
485 status = safe_create_leading_directories_const(path);
486 if (status) {
487 if (status == -3) {
488 /* something else exists */
489 error(msg, path, ": perhaps a D/F conflict?");
490 return -1;
492 die(msg, path, "");
496 * Do not unlink a file in the work tree if we are not
497 * tracking it.
499 if (would_lose_untracked(path))
500 return error("refusing to lose untracked file at '%s'",
501 path);
503 /* Successful unlink is good.. */
504 if (!unlink(path))
505 return 0;
506 /* .. and so is no existing file */
507 if (errno == ENOENT)
508 return 0;
509 /* .. but not some other error (who really cares what?) */
510 return error(msg, path, ": perhaps a D/F conflict?");
513 static void update_file_flags(struct merge_options *o,
514 const unsigned char *sha,
515 unsigned mode,
516 const char *path,
517 int update_cache,
518 int update_wd)
520 if (o->call_depth)
521 update_wd = 0;
523 if (update_wd) {
524 enum object_type type;
525 void *buf;
526 unsigned long size;
528 if (S_ISGITLINK(mode))
530 * We may later decide to recursively descend into
531 * the submodule directory and update its index
532 * and/or work tree, but we do not do that now.
534 goto update_index;
536 buf = read_sha1_file(sha, &type, &size);
537 if (!buf)
538 die("cannot read object %s '%s'", sha1_to_hex(sha), path);
539 if (type != OBJ_BLOB)
540 die("blob expected for %s '%s'", sha1_to_hex(sha), path);
541 if (S_ISREG(mode)) {
542 struct strbuf strbuf = STRBUF_INIT;
543 if (convert_to_working_tree(path, buf, size, &strbuf)) {
544 free(buf);
545 size = strbuf.len;
546 buf = strbuf_detach(&strbuf, NULL);
550 if (make_room_for_path(path) < 0) {
551 update_wd = 0;
552 free(buf);
553 goto update_index;
555 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
556 int fd;
557 if (mode & 0100)
558 mode = 0777;
559 else
560 mode = 0666;
561 fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
562 if (fd < 0)
563 die_errno("failed to open '%s'", path);
564 flush_buffer(fd, buf, size);
565 close(fd);
566 } else if (S_ISLNK(mode)) {
567 char *lnk = xmemdupz(buf, size);
568 safe_create_leading_directories_const(path);
569 unlink(path);
570 if (symlink(lnk, path))
571 die_errno("failed to symlink '%s'", path);
572 free(lnk);
573 } else
574 die("do not know what to do with %06o %s '%s'",
575 mode, sha1_to_hex(sha), path);
576 free(buf);
578 update_index:
579 if (update_cache)
580 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
583 static void update_file(struct merge_options *o,
584 int clean,
585 const unsigned char *sha,
586 unsigned mode,
587 const char *path)
589 update_file_flags(o, sha, mode, path, o->call_depth || clean, !o->call_depth);
592 /* Low level file merging, update and removal */
594 struct merge_file_info
596 unsigned char sha[20];
597 unsigned mode;
598 unsigned clean:1,
599 merge:1;
602 static int merge_3way(struct merge_options *o,
603 mmbuffer_t *result_buf,
604 struct diff_filespec *one,
605 struct diff_filespec *a,
606 struct diff_filespec *b,
607 const char *branch1,
608 const char *branch2)
610 mmfile_t orig, src1, src2;
611 char *base_name, *name1, *name2;
612 int merge_status;
613 int favor;
615 if (o->call_depth)
616 favor = 0;
617 else {
618 switch (o->recursive_variant) {
619 case MERGE_RECURSIVE_OURS:
620 favor = XDL_MERGE_FAVOR_OURS;
621 break;
622 case MERGE_RECURSIVE_THEIRS:
623 favor = XDL_MERGE_FAVOR_THEIRS;
624 break;
625 default:
626 favor = 0;
627 break;
631 if (strcmp(a->path, b->path) ||
632 (o->ancestor != NULL && strcmp(a->path, one->path) != 0)) {
633 base_name = o->ancestor == NULL ? NULL :
634 xstrdup(mkpath("%s:%s", o->ancestor, one->path));
635 name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
636 name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
637 } else {
638 base_name = o->ancestor == NULL ? NULL :
639 xstrdup(mkpath("%s", o->ancestor));
640 name1 = xstrdup(mkpath("%s", branch1));
641 name2 = xstrdup(mkpath("%s", branch2));
644 read_mmblob(&orig, one->sha1);
645 read_mmblob(&src1, a->sha1);
646 read_mmblob(&src2, b->sha1);
648 merge_status = ll_merge(result_buf, a->path, &orig, base_name,
649 &src1, name1, &src2, name2,
650 (!!o->call_depth) | (favor << 1));
652 free(name1);
653 free(name2);
654 free(orig.ptr);
655 free(src1.ptr);
656 free(src2.ptr);
657 return merge_status;
660 static struct merge_file_info merge_file(struct merge_options *o,
661 struct diff_filespec *one,
662 struct diff_filespec *a,
663 struct diff_filespec *b,
664 const char *branch1,
665 const char *branch2)
667 struct merge_file_info result;
668 result.merge = 0;
669 result.clean = 1;
671 if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
672 result.clean = 0;
673 if (S_ISREG(a->mode)) {
674 result.mode = a->mode;
675 hashcpy(result.sha, a->sha1);
676 } else {
677 result.mode = b->mode;
678 hashcpy(result.sha, b->sha1);
680 } else {
681 if (!sha_eq(a->sha1, one->sha1) && !sha_eq(b->sha1, one->sha1))
682 result.merge = 1;
685 * Merge modes
687 if (a->mode == b->mode || a->mode == one->mode)
688 result.mode = b->mode;
689 else {
690 result.mode = a->mode;
691 if (b->mode != one->mode) {
692 result.clean = 0;
693 result.merge = 1;
697 if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, one->sha1))
698 hashcpy(result.sha, b->sha1);
699 else if (sha_eq(b->sha1, one->sha1))
700 hashcpy(result.sha, a->sha1);
701 else if (S_ISREG(a->mode)) {
702 mmbuffer_t result_buf;
703 int merge_status;
705 merge_status = merge_3way(o, &result_buf, one, a, b,
706 branch1, branch2);
708 if ((merge_status < 0) || !result_buf.ptr)
709 die("Failed to execute internal merge");
711 if (write_sha1_file(result_buf.ptr, result_buf.size,
712 blob_type, result.sha))
713 die("Unable to add %s to database",
714 a->path);
716 free(result_buf.ptr);
717 result.clean = (merge_status == 0);
718 } else if (S_ISGITLINK(a->mode)) {
719 result.clean = 0;
720 hashcpy(result.sha, a->sha1);
721 } else if (S_ISLNK(a->mode)) {
722 hashcpy(result.sha, a->sha1);
724 if (!sha_eq(a->sha1, b->sha1))
725 result.clean = 0;
726 } else {
727 die("unsupported object type in the tree");
731 return result;
734 static void conflict_rename_rename(struct merge_options *o,
735 struct rename *ren1,
736 const char *branch1,
737 struct rename *ren2,
738 const char *branch2)
740 char *del[2];
741 int delp = 0;
742 const char *ren1_dst = ren1->pair->two->path;
743 const char *ren2_dst = ren2->pair->two->path;
744 const char *dst_name1 = ren1_dst;
745 const char *dst_name2 = ren2_dst;
746 if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
747 dst_name1 = del[delp++] = unique_path(o, ren1_dst, branch1);
748 output(o, 1, "%s is a directory in %s adding as %s instead",
749 ren1_dst, branch2, dst_name1);
750 remove_file(o, 0, ren1_dst, 0);
752 if (string_list_has_string(&o->current_directory_set, ren2_dst)) {
753 dst_name2 = del[delp++] = unique_path(o, ren2_dst, branch2);
754 output(o, 1, "%s is a directory in %s adding as %s instead",
755 ren2_dst, branch1, dst_name2);
756 remove_file(o, 0, ren2_dst, 0);
758 if (o->call_depth) {
759 remove_file_from_cache(dst_name1);
760 remove_file_from_cache(dst_name2);
762 * Uncomment to leave the conflicting names in the resulting tree
764 * update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
765 * update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
767 } else {
768 update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
769 update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
771 while (delp--)
772 free(del[delp]);
775 static void conflict_rename_dir(struct merge_options *o,
776 struct rename *ren1,
777 const char *branch1)
779 char *new_path = unique_path(o, ren1->pair->two->path, branch1);
780 output(o, 1, "Renaming %s to %s instead", ren1->pair->one->path, new_path);
781 remove_file(o, 0, ren1->pair->two->path, 0);
782 update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
783 free(new_path);
786 static void conflict_rename_rename_2(struct merge_options *o,
787 struct rename *ren1,
788 const char *branch1,
789 struct rename *ren2,
790 const char *branch2)
792 char *new_path1 = unique_path(o, ren1->pair->two->path, branch1);
793 char *new_path2 = unique_path(o, ren2->pair->two->path, branch2);
794 output(o, 1, "Renaming %s to %s and %s to %s instead",
795 ren1->pair->one->path, new_path1,
796 ren2->pair->one->path, new_path2);
797 remove_file(o, 0, ren1->pair->two->path, 0);
798 update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
799 update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
800 free(new_path2);
801 free(new_path1);
804 static int process_renames(struct merge_options *o,
805 struct string_list *a_renames,
806 struct string_list *b_renames)
808 int clean_merge = 1, i, j;
809 struct string_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
810 const struct rename *sre;
812 for (i = 0; i < a_renames->nr; i++) {
813 sre = a_renames->items[i].util;
814 string_list_insert(sre->pair->two->path, &a_by_dst)->util
815 = sre->dst_entry;
817 for (i = 0; i < b_renames->nr; i++) {
818 sre = b_renames->items[i].util;
819 string_list_insert(sre->pair->two->path, &b_by_dst)->util
820 = sre->dst_entry;
823 for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
824 char *src;
825 struct string_list *renames1, *renames2Dst;
826 struct rename *ren1 = NULL, *ren2 = NULL;
827 const char *branch1, *branch2;
828 const char *ren1_src, *ren1_dst;
830 if (i >= a_renames->nr) {
831 ren2 = b_renames->items[j++].util;
832 } else if (j >= b_renames->nr) {
833 ren1 = a_renames->items[i++].util;
834 } else {
835 int compare = strcmp(a_renames->items[i].string,
836 b_renames->items[j].string);
837 if (compare <= 0)
838 ren1 = a_renames->items[i++].util;
839 if (compare >= 0)
840 ren2 = b_renames->items[j++].util;
843 /* TODO: refactor, so that 1/2 are not needed */
844 if (ren1) {
845 renames1 = a_renames;
846 renames2Dst = &b_by_dst;
847 branch1 = o->branch1;
848 branch2 = o->branch2;
849 } else {
850 struct rename *tmp;
851 renames1 = b_renames;
852 renames2Dst = &a_by_dst;
853 branch1 = o->branch2;
854 branch2 = o->branch1;
855 tmp = ren2;
856 ren2 = ren1;
857 ren1 = tmp;
859 src = ren1->pair->one->path;
861 ren1->dst_entry->processed = 1;
862 ren1->src_entry->processed = 1;
864 if (ren1->processed)
865 continue;
866 ren1->processed = 1;
868 ren1_src = ren1->pair->one->path;
869 ren1_dst = ren1->pair->two->path;
871 if (ren2) {
872 const char *ren2_src = ren2->pair->one->path;
873 const char *ren2_dst = ren2->pair->two->path;
874 /* Renamed in 1 and renamed in 2 */
875 if (strcmp(ren1_src, ren2_src) != 0)
876 die("ren1.src != ren2.src");
877 ren2->dst_entry->processed = 1;
878 ren2->processed = 1;
879 if (strcmp(ren1_dst, ren2_dst) != 0) {
880 clean_merge = 0;
881 output(o, 1, "CONFLICT (rename/rename): "
882 "Rename \"%s\"->\"%s\" in branch \"%s\" "
883 "rename \"%s\"->\"%s\" in \"%s\"%s",
884 src, ren1_dst, branch1,
885 src, ren2_dst, branch2,
886 o->call_depth ? " (left unresolved)": "");
887 if (o->call_depth) {
888 remove_file_from_cache(src);
889 update_file(o, 0, ren1->pair->one->sha1,
890 ren1->pair->one->mode, src);
892 conflict_rename_rename(o, ren1, branch1, ren2, branch2);
893 } else {
894 struct merge_file_info mfi;
895 remove_file(o, 1, ren1_src, 1);
896 mfi = merge_file(o,
897 ren1->pair->one,
898 ren1->pair->two,
899 ren2->pair->two,
900 branch1,
901 branch2);
902 if (mfi.merge || !mfi.clean)
903 output(o, 1, "Renaming %s->%s", src, ren1_dst);
905 if (mfi.merge)
906 output(o, 2, "Auto-merging %s", ren1_dst);
908 if (!mfi.clean) {
909 output(o, 1, "CONFLICT (content): merge conflict in %s",
910 ren1_dst);
911 clean_merge = 0;
913 if (!o->call_depth)
914 update_stages(ren1_dst,
915 ren1->pair->one,
916 ren1->pair->two,
917 ren2->pair->two,
918 1 /* clear */);
920 update_file(o, mfi.clean, mfi.sha, mfi.mode, ren1_dst);
922 } else {
923 /* Renamed in 1, maybe changed in 2 */
924 struct string_list_item *item;
925 /* we only use sha1 and mode of these */
926 struct diff_filespec src_other, dst_other;
927 int try_merge, stage = a_renames == renames1 ? 3: 2;
929 remove_file(o, 1, ren1_src, o->call_depth || stage == 3);
931 hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
932 src_other.mode = ren1->src_entry->stages[stage].mode;
933 hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
934 dst_other.mode = ren1->dst_entry->stages[stage].mode;
936 try_merge = 0;
938 if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
939 clean_merge = 0;
940 output(o, 1, "CONFLICT (rename/directory): Rename %s->%s in %s "
941 " directory %s added in %s",
942 ren1_src, ren1_dst, branch1,
943 ren1_dst, branch2);
944 conflict_rename_dir(o, ren1, branch1);
945 } else if (sha_eq(src_other.sha1, null_sha1)) {
946 clean_merge = 0;
947 output(o, 1, "CONFLICT (rename/delete): Rename %s->%s in %s "
948 "and deleted in %s",
949 ren1_src, ren1_dst, branch1,
950 branch2);
951 update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
952 if (!o->call_depth)
953 update_stages(ren1_dst, NULL,
954 branch1 == o->branch1 ?
955 ren1->pair->two : NULL,
956 branch1 == o->branch1 ?
957 NULL : ren1->pair->two, 1);
958 } else if (!sha_eq(dst_other.sha1, null_sha1)) {
959 const char *new_path;
960 clean_merge = 0;
961 try_merge = 1;
962 output(o, 1, "CONFLICT (rename/add): Rename %s->%s in %s. "
963 "%s added in %s",
964 ren1_src, ren1_dst, branch1,
965 ren1_dst, branch2);
966 if (o->call_depth) {
967 struct merge_file_info mfi;
968 struct diff_filespec one, a, b;
970 one.path = a.path = b.path =
971 (char *)ren1_dst;
972 hashcpy(one.sha1, null_sha1);
973 one.mode = 0;
974 hashcpy(a.sha1, ren1->pair->two->sha1);
975 a.mode = ren1->pair->two->mode;
976 hashcpy(b.sha1, dst_other.sha1);
977 b.mode = dst_other.mode;
978 mfi = merge_file(o, &one, &a, &b,
979 branch1,
980 branch2);
981 output(o, 1, "Adding merged %s", ren1_dst);
982 update_file(o, 0,
983 mfi.sha,
984 mfi.mode,
985 ren1_dst);
986 } else {
987 new_path = unique_path(o, ren1_dst, branch2);
988 output(o, 1, "Adding as %s instead", new_path);
989 update_file(o, 0, dst_other.sha1, dst_other.mode, new_path);
991 } else if ((item = string_list_lookup(ren1_dst, renames2Dst))) {
992 ren2 = item->util;
993 clean_merge = 0;
994 ren2->processed = 1;
995 output(o, 1, "CONFLICT (rename/rename): "
996 "Rename %s->%s in %s. "
997 "Rename %s->%s in %s",
998 ren1_src, ren1_dst, branch1,
999 ren2->pair->one->path, ren2->pair->two->path, branch2);
1000 conflict_rename_rename_2(o, ren1, branch1, ren2, branch2);
1001 } else
1002 try_merge = 1;
1004 if (try_merge) {
1005 struct diff_filespec *one, *a, *b;
1006 struct merge_file_info mfi;
1007 src_other.path = (char *)ren1_src;
1009 one = ren1->pair->one;
1010 if (a_renames == renames1) {
1011 a = ren1->pair->two;
1012 b = &src_other;
1013 } else {
1014 b = ren1->pair->two;
1015 a = &src_other;
1017 mfi = merge_file(o, one, a, b,
1018 o->branch1, o->branch2);
1020 if (mfi.clean &&
1021 sha_eq(mfi.sha, ren1->pair->two->sha1) &&
1022 mfi.mode == ren1->pair->two->mode)
1024 * This messaged is part of
1025 * t6022 test. If you change
1026 * it update the test too.
1028 output(o, 3, "Skipped %s (merged same as existing)", ren1_dst);
1029 else {
1030 if (mfi.merge || !mfi.clean)
1031 output(o, 1, "Renaming %s => %s", ren1_src, ren1_dst);
1032 if (mfi.merge)
1033 output(o, 2, "Auto-merging %s", ren1_dst);
1034 if (!mfi.clean) {
1035 output(o, 1, "CONFLICT (rename/modify): Merge conflict in %s",
1036 ren1_dst);
1037 clean_merge = 0;
1039 if (!o->call_depth)
1040 update_stages(ren1_dst,
1041 one, a, b, 1);
1043 update_file(o, mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1048 string_list_clear(&a_by_dst, 0);
1049 string_list_clear(&b_by_dst, 0);
1051 return clean_merge;
1054 static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1056 return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1059 /* Per entry merge function */
1060 static int process_entry(struct merge_options *o,
1061 const char *path, struct stage_data *entry)
1064 printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1065 print_index_entry("\tpath: ", entry);
1067 int clean_merge = 1;
1068 unsigned o_mode = entry->stages[1].mode;
1069 unsigned a_mode = entry->stages[2].mode;
1070 unsigned b_mode = entry->stages[3].mode;
1071 unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1072 unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1073 unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1075 if (o_sha && (!a_sha || !b_sha)) {
1076 /* Case A: Deleted in one */
1077 if ((!a_sha && !b_sha) ||
1078 (sha_eq(a_sha, o_sha) && !b_sha) ||
1079 (!a_sha && sha_eq(b_sha, o_sha))) {
1080 /* Deleted in both or deleted in one and
1081 * unchanged in the other */
1082 if (a_sha)
1083 output(o, 2, "Removing %s", path);
1084 /* do not touch working file if it did not exist */
1085 remove_file(o, 1, path, !a_sha);
1086 } else {
1087 /* Deleted in one and changed in the other */
1088 clean_merge = 0;
1089 if (!a_sha) {
1090 output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1091 "and modified in %s. Version %s of %s left in tree.",
1092 path, o->branch1,
1093 o->branch2, o->branch2, path);
1094 update_file(o, 0, b_sha, b_mode, path);
1095 } else {
1096 output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1097 "and modified in %s. Version %s of %s left in tree.",
1098 path, o->branch2,
1099 o->branch1, o->branch1, path);
1100 update_file(o, 0, a_sha, a_mode, path);
1104 } else if ((!o_sha && a_sha && !b_sha) ||
1105 (!o_sha && !a_sha && b_sha)) {
1106 /* Case B: Added in one. */
1107 const char *add_branch;
1108 const char *other_branch;
1109 unsigned mode;
1110 const unsigned char *sha;
1111 const char *conf;
1113 if (a_sha) {
1114 add_branch = o->branch1;
1115 other_branch = o->branch2;
1116 mode = a_mode;
1117 sha = a_sha;
1118 conf = "file/directory";
1119 } else {
1120 add_branch = o->branch2;
1121 other_branch = o->branch1;
1122 mode = b_mode;
1123 sha = b_sha;
1124 conf = "directory/file";
1126 if (string_list_has_string(&o->current_directory_set, path)) {
1127 const char *new_path = unique_path(o, path, add_branch);
1128 clean_merge = 0;
1129 output(o, 1, "CONFLICT (%s): There is a directory with name %s in %s. "
1130 "Adding %s as %s",
1131 conf, path, other_branch, path, new_path);
1132 remove_file(o, 0, path, 0);
1133 update_file(o, 0, sha, mode, new_path);
1134 } else {
1135 output(o, 2, "Adding %s", path);
1136 update_file(o, 1, sha, mode, path);
1138 } else if (a_sha && b_sha) {
1139 /* Case C: Added in both (check for same permissions) and */
1140 /* case D: Modified in both, but differently. */
1141 const char *reason = "content";
1142 struct merge_file_info mfi;
1143 struct diff_filespec one, a, b;
1145 if (!o_sha) {
1146 reason = "add/add";
1147 o_sha = (unsigned char *)null_sha1;
1149 output(o, 2, "Auto-merging %s", path);
1150 one.path = a.path = b.path = (char *)path;
1151 hashcpy(one.sha1, o_sha);
1152 one.mode = o_mode;
1153 hashcpy(a.sha1, a_sha);
1154 a.mode = a_mode;
1155 hashcpy(b.sha1, b_sha);
1156 b.mode = b_mode;
1158 mfi = merge_file(o, &one, &a, &b,
1159 o->branch1, o->branch2);
1161 clean_merge = mfi.clean;
1162 if (!mfi.clean) {
1163 if (S_ISGITLINK(mfi.mode))
1164 reason = "submodule";
1165 output(o, 1, "CONFLICT (%s): Merge conflict in %s",
1166 reason, path);
1168 update_file(o, mfi.clean, mfi.sha, mfi.mode, path);
1169 } else if (!o_sha && !a_sha && !b_sha) {
1171 * this entry was deleted altogether. a_mode == 0 means
1172 * we had that path and want to actively remove it.
1174 remove_file(o, 1, path, !a_mode);
1175 } else
1176 die("Fatal merge failure, shouldn't happen.");
1178 return clean_merge;
1181 struct unpack_trees_error_msgs get_porcelain_error_msgs(void)
1183 struct unpack_trees_error_msgs msgs = {
1184 /* would_overwrite */
1185 "Your local changes to '%s' would be overwritten by merge. Aborting.",
1186 /* not_uptodate_file */
1187 "Your local changes to '%s' would be overwritten by merge. Aborting.",
1188 /* not_uptodate_dir */
1189 "Updating '%s' would lose untracked files in it. Aborting.",
1190 /* would_lose_untracked */
1191 "Untracked working tree file '%s' would be %s by merge. Aborting",
1192 /* bind_overlap -- will not happen here */
1193 NULL,
1195 if (advice_commit_before_merge) {
1196 msgs.would_overwrite = msgs.not_uptodate_file =
1197 "Your local changes to '%s' would be overwritten by merge. Aborting.\n"
1198 "Please, commit your changes or stash them before you can merge.";
1200 return msgs;
1203 int merge_trees(struct merge_options *o,
1204 struct tree *head,
1205 struct tree *merge,
1206 struct tree *common,
1207 struct tree **result)
1209 int code, clean;
1211 if (o->subtree_shift) {
1212 merge = shift_tree_object(head, merge, o->subtree_shift);
1213 common = shift_tree_object(head, common, o->subtree_shift);
1216 if (sha_eq(common->object.sha1, merge->object.sha1)) {
1217 output(o, 0, "Already uptodate!");
1218 *result = head;
1219 return 1;
1222 code = git_merge_trees(o->call_depth, common, head, merge);
1224 if (code != 0) {
1225 if (show(o, 4) || o->call_depth)
1226 die("merging of trees %s and %s failed",
1227 sha1_to_hex(head->object.sha1),
1228 sha1_to_hex(merge->object.sha1));
1229 else
1230 exit(128);
1233 if (unmerged_cache()) {
1234 struct string_list *entries, *re_head, *re_merge;
1235 int i;
1236 string_list_clear(&o->current_file_set, 1);
1237 string_list_clear(&o->current_directory_set, 1);
1238 get_files_dirs(o, head);
1239 get_files_dirs(o, merge);
1241 entries = get_unmerged();
1242 re_head = get_renames(o, head, common, head, merge, entries);
1243 re_merge = get_renames(o, merge, common, head, merge, entries);
1244 clean = process_renames(o, re_head, re_merge);
1245 for (i = 0; i < entries->nr; i++) {
1246 const char *path = entries->items[i].string;
1247 struct stage_data *e = entries->items[i].util;
1248 if (!e->processed
1249 && !process_entry(o, path, e))
1250 clean = 0;
1253 string_list_clear(re_merge, 0);
1254 string_list_clear(re_head, 0);
1255 string_list_clear(entries, 1);
1258 else
1259 clean = 1;
1261 if (o->call_depth)
1262 *result = write_tree_from_memory(o);
1264 return clean;
1267 static struct commit_list *reverse_commit_list(struct commit_list *list)
1269 struct commit_list *next = NULL, *current, *backup;
1270 for (current = list; current; current = backup) {
1271 backup = current->next;
1272 current->next = next;
1273 next = current;
1275 return next;
1279 * Merge the commits h1 and h2, return the resulting virtual
1280 * commit object and a flag indicating the cleanness of the merge.
1282 int merge_recursive(struct merge_options *o,
1283 struct commit *h1,
1284 struct commit *h2,
1285 struct commit_list *ca,
1286 struct commit **result)
1288 struct commit_list *iter;
1289 struct commit *merged_common_ancestors;
1290 struct tree *mrtree = mrtree;
1291 int clean;
1293 if (show(o, 4)) {
1294 output(o, 4, "Merging:");
1295 output_commit_title(o, h1);
1296 output_commit_title(o, h2);
1299 if (!ca) {
1300 ca = get_merge_bases(h1, h2, 1);
1301 ca = reverse_commit_list(ca);
1304 if (show(o, 5)) {
1305 output(o, 5, "found %u common ancestor(s):", commit_list_count(ca));
1306 for (iter = ca; iter; iter = iter->next)
1307 output_commit_title(o, iter->item);
1310 merged_common_ancestors = pop_commit(&ca);
1311 if (merged_common_ancestors == NULL) {
1312 /* if there is no common ancestor, make an empty tree */
1313 struct tree *tree = xcalloc(1, sizeof(struct tree));
1315 tree->object.parsed = 1;
1316 tree->object.type = OBJ_TREE;
1317 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1318 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1321 for (iter = ca; iter; iter = iter->next) {
1322 const char *saved_b1, *saved_b2;
1323 o->call_depth++;
1325 * When the merge fails, the result contains files
1326 * with conflict markers. The cleanness flag is
1327 * ignored, it was never actually used, as result of
1328 * merge_trees has always overwritten it: the committed
1329 * "conflicts" were already resolved.
1331 discard_cache();
1332 saved_b1 = o->branch1;
1333 saved_b2 = o->branch2;
1334 o->branch1 = "Temporary merge branch 1";
1335 o->branch2 = "Temporary merge branch 2";
1336 merge_recursive(o, merged_common_ancestors, iter->item,
1337 NULL, &merged_common_ancestors);
1338 o->branch1 = saved_b1;
1339 o->branch2 = saved_b2;
1340 o->call_depth--;
1342 if (!merged_common_ancestors)
1343 die("merge returned no commit");
1346 discard_cache();
1347 if (!o->call_depth)
1348 read_cache();
1350 o->ancestor = "merged common ancestors";
1351 clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
1352 &mrtree);
1354 if (o->call_depth) {
1355 *result = make_virtual_commit(mrtree, "merged tree");
1356 commit_list_insert(h1, &(*result)->parents);
1357 commit_list_insert(h2, &(*result)->parents->next);
1359 flush_output(o);
1360 return clean;
1363 static struct commit *get_ref(const unsigned char *sha1, const char *name)
1365 struct object *object;
1367 object = deref_tag(parse_object(sha1), name, strlen(name));
1368 if (!object)
1369 return NULL;
1370 if (object->type == OBJ_TREE)
1371 return make_virtual_commit((struct tree*)object, name);
1372 if (object->type != OBJ_COMMIT)
1373 return NULL;
1374 if (parse_commit((struct commit *)object))
1375 return NULL;
1376 return (struct commit *)object;
1379 int merge_recursive_generic(struct merge_options *o,
1380 const unsigned char *head,
1381 const unsigned char *merge,
1382 int num_base_list,
1383 const unsigned char **base_list,
1384 struct commit **result)
1386 int clean, index_fd;
1387 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1388 struct commit *head_commit = get_ref(head, o->branch1);
1389 struct commit *next_commit = get_ref(merge, o->branch2);
1390 struct commit_list *ca = NULL;
1392 if (base_list) {
1393 int i;
1394 for (i = 0; i < num_base_list; ++i) {
1395 struct commit *base;
1396 if (!(base = get_ref(base_list[i], sha1_to_hex(base_list[i]))))
1397 return error("Could not parse object '%s'",
1398 sha1_to_hex(base_list[i]));
1399 commit_list_insert(base, &ca);
1403 index_fd = hold_locked_index(lock, 1);
1404 clean = merge_recursive(o, head_commit, next_commit, ca,
1405 result);
1406 if (active_cache_changed &&
1407 (write_cache(index_fd, active_cache, active_nr) ||
1408 commit_locked_index(lock)))
1409 return error("Unable to write index.");
1411 return clean ? 0 : 1;
1414 static int merge_recursive_config(const char *var, const char *value, void *cb)
1416 struct merge_options *o = cb;
1417 if (!strcasecmp(var, "merge.verbosity")) {
1418 o->verbosity = git_config_int(var, value);
1419 return 0;
1421 if (!strcasecmp(var, "diff.renamelimit")) {
1422 o->diff_rename_limit = git_config_int(var, value);
1423 return 0;
1425 if (!strcasecmp(var, "merge.renamelimit")) {
1426 o->merge_rename_limit = git_config_int(var, value);
1427 return 0;
1429 return git_xmerge_config(var, value, cb);
1432 void init_merge_options(struct merge_options *o)
1434 memset(o, 0, sizeof(struct merge_options));
1435 o->verbosity = 2;
1436 o->buffer_output = 1;
1437 o->diff_rename_limit = -1;
1438 o->merge_rename_limit = -1;
1439 git_config(merge_recursive_config, o);
1440 if (getenv("GIT_MERGE_VERBOSITY"))
1441 o->verbosity =
1442 strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1443 if (o->verbosity >= 5)
1444 o->buffer_output = 0;
1445 strbuf_init(&o->obuf, 0);
1446 memset(&o->current_file_set, 0, sizeof(struct string_list));
1447 o->current_file_set.strdup_strings = 1;
1448 memset(&o->current_directory_set, 0, sizeof(struct string_list));
1449 o->current_directory_set.strdup_strings = 1;