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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 "cache.h"
7 #include "cache-tree.h"
8 #include "commit.h"
9 #include "blob.h"
10 #include "builtin.h"
11 #include "tree-walk.h"
12 #include "diff.h"
13 #include "diffcore.h"
14 #include "tag.h"
15 #include "unpack-trees.h"
16 #include "path-list.h"
17 #include "xdiff-interface.h"
18 #include "ll-merge.h"
19 #include "interpolate.h"
20 #include "attr.h"
21 #include "merge-recursive.h"
23 static int subtree_merge;
25 static struct tree *shift_tree_object(struct tree *one, struct tree *two)
26 {
27 unsigned char shifted[20];
29 /*
30 * NEEDSWORK: this limits the recursion depth to hardcoded
31 * value '2' to avoid excessive overhead.
32 */
33 shift_tree(one->object.sha1, two->object.sha1, shifted, 2);
34 if (!hashcmp(two->object.sha1, shifted))
35 return two;
36 return lookup_tree(shifted);
37 }
39 /*
40 * A virtual commit has
41 * - (const char *)commit->util set to the name, and
42 * - *(int *)commit->object.sha1 set to the virtual id.
43 */
45 static unsigned commit_list_count(const struct commit_list *l)
46 {
47 unsigned c = 0;
48 for (; l; l = l->next )
49 c++;
50 return c;
51 }
53 static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
54 {
55 struct commit *commit = xcalloc(1, sizeof(struct commit));
56 static unsigned virtual_id = 1;
57 commit->tree = tree;
58 commit->util = (void*)comment;
59 *(int*)commit->object.sha1 = virtual_id++;
60 /* avoid warnings */
61 commit->object.parsed = 1;
62 return commit;
63 }
65 /*
66 * Since we use get_tree_entry(), which does not put the read object into
67 * the object pool, we cannot rely on a == b.
68 */
69 static int sha_eq(const unsigned char *a, const unsigned char *b)
70 {
71 if (!a && !b)
72 return 2;
73 return a && b && hashcmp(a, b) == 0;
74 }
76 /*
77 * Since we want to write the index eventually, we cannot reuse the index
78 * for these (temporary) data.
79 */
80 struct stage_data
81 {
82 struct
83 {
84 unsigned mode;
85 unsigned char sha[20];
86 } stages[4];
87 unsigned processed:1;
88 };
90 static struct path_list current_file_set = {NULL, 0, 0, 1};
91 static struct path_list current_directory_set = {NULL, 0, 0, 1};
93 static int call_depth = 0;
94 static int verbosity = 2;
95 static int rename_limit = -1;
96 static int buffer_output = 1;
97 static struct strbuf obuf = STRBUF_INIT;
99 static int show(int v)
100 {
101 return (!call_depth && verbosity >= v) || verbosity >= 5;
102 }
104 static void flush_output(void)
105 {
106 if (obuf.len) {
107 fputs(obuf.buf, stdout);
108 strbuf_reset(&obuf);
109 }
110 }
112 static void output(int v, const char *fmt, ...)
113 {
114 int len;
115 va_list ap;
117 if (!show(v))
118 return;
120 strbuf_grow(&obuf, call_depth * 2 + 2);
121 memset(obuf.buf + obuf.len, ' ', call_depth * 2);
122 strbuf_setlen(&obuf, obuf.len + call_depth * 2);
124 va_start(ap, fmt);
125 len = vsnprintf(obuf.buf + obuf.len, strbuf_avail(&obuf), fmt, ap);
126 va_end(ap);
128 if (len < 0)
129 len = 0;
130 if (len >= strbuf_avail(&obuf)) {
131 strbuf_grow(&obuf, len + 2);
132 va_start(ap, fmt);
133 len = vsnprintf(obuf.buf + obuf.len, strbuf_avail(&obuf), fmt, ap);
134 va_end(ap);
135 if (len >= strbuf_avail(&obuf)) {
136 die("this should not happen, your snprintf is broken");
137 }
138 }
139 strbuf_setlen(&obuf, obuf.len + len);
140 strbuf_add(&obuf, "\n", 1);
141 if (!buffer_output)
142 flush_output();
143 }
145 static void output_commit_title(struct commit *commit)
146 {
147 int i;
148 flush_output();
149 for (i = call_depth; i--;)
150 fputs(" ", stdout);
151 if (commit->util)
152 printf("virtual %s\n", (char *)commit->util);
153 else {
154 printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
155 if (parse_commit(commit) != 0)
156 printf("(bad commit)\n");
157 else {
158 const char *s;
159 int len;
160 for (s = commit->buffer; *s; s++)
161 if (*s == '\n' && s[1] == '\n') {
162 s += 2;
163 break;
164 }
165 for (len = 0; s[len] && '\n' != s[len]; len++)
166 ; /* do nothing */
167 printf("%.*s\n", len, s);
168 }
169 }
170 }
172 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
173 const char *path, int stage, int refresh, int options)
174 {
175 struct cache_entry *ce;
176 ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
177 if (!ce)
178 return error("addinfo_cache failed for path '%s'", path);
179 return add_cache_entry(ce, options);
180 }
182 /*
183 * This is a global variable which is used in a number of places but
184 * only written to in the 'merge' function.
185 *
186 * index_only == 1 => Don't leave any non-stage 0 entries in the cache and
187 * don't update the working directory.
188 * 0 => Leave unmerged entries in the cache and update
189 * the working directory.
190 */
191 static int index_only = 0;
193 static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
194 {
195 parse_tree(tree);
196 init_tree_desc(desc, tree->buffer, tree->size);
197 }
199 static int git_merge_trees(int index_only,
200 struct tree *common,
201 struct tree *head,
202 struct tree *merge)
203 {
204 int rc;
205 struct tree_desc t[3];
206 struct unpack_trees_options opts;
208 memset(&opts, 0, sizeof(opts));
209 if (index_only)
210 opts.index_only = 1;
211 else
212 opts.update = 1;
213 opts.merge = 1;
214 opts.head_idx = 2;
215 opts.fn = threeway_merge;
216 opts.src_index = &the_index;
217 opts.dst_index = &the_index;
219 init_tree_desc_from_tree(t+0, common);
220 init_tree_desc_from_tree(t+1, head);
221 init_tree_desc_from_tree(t+2, merge);
223 rc = unpack_trees(3, t, &opts);
224 cache_tree_free(&active_cache_tree);
225 return rc;
226 }
228 struct tree *write_tree_from_memory(void)
229 {
230 struct tree *result = NULL;
232 if (unmerged_cache()) {
233 int i;
234 output(0, "There are unmerged index entries:");
235 for (i = 0; i < active_nr; i++) {
236 struct cache_entry *ce = active_cache[i];
237 if (ce_stage(ce))
238 output(0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
239 }
240 return NULL;
241 }
243 if (!active_cache_tree)
244 active_cache_tree = cache_tree();
246 if (!cache_tree_fully_valid(active_cache_tree) &&
247 cache_tree_update(active_cache_tree,
248 active_cache, active_nr, 0, 0) < 0)
249 die("error building trees");
251 result = lookup_tree(active_cache_tree->sha1);
253 return result;
254 }
256 static int save_files_dirs(const unsigned char *sha1,
257 const char *base, int baselen, const char *path,
258 unsigned int mode, int stage)
259 {
260 int len = strlen(path);
261 char *newpath = xmalloc(baselen + len + 1);
262 memcpy(newpath, base, baselen);
263 memcpy(newpath + baselen, path, len);
264 newpath[baselen + len] = '\0';
266 if (S_ISDIR(mode))
267 path_list_insert(newpath, ¤t_directory_set);
268 else
269 path_list_insert(newpath, ¤t_file_set);
270 free(newpath);
272 return READ_TREE_RECURSIVE;
273 }
275 static int get_files_dirs(struct tree *tree)
276 {
277 int n;
278 if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs) != 0)
279 return 0;
280 n = current_file_set.nr + current_directory_set.nr;
281 return n;
282 }
284 /*
285 * Returns an index_entry instance which doesn't have to correspond to
286 * a real cache entry in Git's index.
287 */
288 static struct stage_data *insert_stage_data(const char *path,
289 struct tree *o, struct tree *a, struct tree *b,
290 struct path_list *entries)
291 {
292 struct path_list_item *item;
293 struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
294 get_tree_entry(o->object.sha1, path,
295 e->stages[1].sha, &e->stages[1].mode);
296 get_tree_entry(a->object.sha1, path,
297 e->stages[2].sha, &e->stages[2].mode);
298 get_tree_entry(b->object.sha1, path,
299 e->stages[3].sha, &e->stages[3].mode);
300 item = path_list_insert(path, entries);
301 item->util = e;
302 return e;
303 }
305 /*
306 * Create a dictionary mapping file names to stage_data objects. The
307 * dictionary contains one entry for every path with a non-zero stage entry.
308 */
309 static struct path_list *get_unmerged(void)
310 {
311 struct path_list *unmerged = xcalloc(1, sizeof(struct path_list));
312 int i;
314 unmerged->strdup_paths = 1;
316 for (i = 0; i < active_nr; i++) {
317 struct path_list_item *item;
318 struct stage_data *e;
319 struct cache_entry *ce = active_cache[i];
320 if (!ce_stage(ce))
321 continue;
323 item = path_list_lookup(ce->name, unmerged);
324 if (!item) {
325 item = path_list_insert(ce->name, unmerged);
326 item->util = xcalloc(1, sizeof(struct stage_data));
327 }
328 e = item->util;
329 e->stages[ce_stage(ce)].mode = ce->ce_mode;
330 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
331 }
333 return unmerged;
334 }
336 struct rename
337 {
338 struct diff_filepair *pair;
339 struct stage_data *src_entry;
340 struct stage_data *dst_entry;
341 unsigned processed:1;
342 };
344 /*
345 * Get information of all renames which occurred between 'o_tree' and
346 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
347 * 'b_tree') to be able to associate the correct cache entries with
348 * the rename information. 'tree' is always equal to either a_tree or b_tree.
349 */
350 static struct path_list *get_renames(struct tree *tree,
351 struct tree *o_tree,
352 struct tree *a_tree,
353 struct tree *b_tree,
354 struct path_list *entries)
355 {
356 int i;
357 struct path_list *renames;
358 struct diff_options opts;
360 renames = xcalloc(1, sizeof(struct path_list));
361 diff_setup(&opts);
362 DIFF_OPT_SET(&opts, RECURSIVE);
363 opts.detect_rename = DIFF_DETECT_RENAME;
364 opts.rename_limit = rename_limit;
365 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
366 if (diff_setup_done(&opts) < 0)
367 die("diff setup failed");
368 diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
369 diffcore_std(&opts);
370 for (i = 0; i < diff_queued_diff.nr; ++i) {
371 struct path_list_item *item;
372 struct rename *re;
373 struct diff_filepair *pair = diff_queued_diff.queue[i];
374 if (pair->status != 'R') {
375 diff_free_filepair(pair);
376 continue;
377 }
378 re = xmalloc(sizeof(*re));
379 re->processed = 0;
380 re->pair = pair;
381 item = path_list_lookup(re->pair->one->path, entries);
382 if (!item)
383 re->src_entry = insert_stage_data(re->pair->one->path,
384 o_tree, a_tree, b_tree, entries);
385 else
386 re->src_entry = item->util;
388 item = path_list_lookup(re->pair->two->path, entries);
389 if (!item)
390 re->dst_entry = insert_stage_data(re->pair->two->path,
391 o_tree, a_tree, b_tree, entries);
392 else
393 re->dst_entry = item->util;
394 item = path_list_insert(pair->one->path, renames);
395 item->util = re;
396 }
397 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
398 diff_queued_diff.nr = 0;
399 diff_flush(&opts);
400 return renames;
401 }
403 static int update_stages(const char *path, struct diff_filespec *o,
404 struct diff_filespec *a, struct diff_filespec *b,
405 int clear)
406 {
407 int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
408 if (clear)
409 if (remove_file_from_cache(path))
410 return -1;
411 if (o)
412 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
413 return -1;
414 if (a)
415 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
416 return -1;
417 if (b)
418 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
419 return -1;
420 return 0;
421 }
423 static int remove_path(const char *name)
424 {
425 int ret;
426 char *slash, *dirs;
428 ret = unlink(name);
429 if (ret)
430 return ret;
431 dirs = xstrdup(name);
432 while ((slash = strrchr(name, '/'))) {
433 *slash = '\0';
434 if (rmdir(name) != 0)
435 break;
436 }
437 free(dirs);
438 return ret;
439 }
441 static int remove_file(int clean, const char *path, int no_wd)
442 {
443 int update_cache = index_only || clean;
444 int update_working_directory = !index_only && !no_wd;
446 if (update_cache) {
447 if (remove_file_from_cache(path))
448 return -1;
449 }
450 if (update_working_directory) {
451 unlink(path);
452 if (errno != ENOENT || errno != EISDIR)
453 return -1;
454 remove_path(path);
455 }
456 return 0;
457 }
459 static char *unique_path(const char *path, const char *branch)
460 {
461 char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
462 int suffix = 0;
463 struct stat st;
464 char *p = newpath + strlen(path);
465 strcpy(newpath, path);
466 *(p++) = '~';
467 strcpy(p, branch);
468 for (; *p; ++p)
469 if ('/' == *p)
470 *p = '_';
471 while (path_list_has_path(¤t_file_set, newpath) ||
472 path_list_has_path(¤t_directory_set, newpath) ||
473 lstat(newpath, &st) == 0)
474 sprintf(p, "_%d", suffix++);
476 path_list_insert(newpath, ¤t_file_set);
477 return newpath;
478 }
480 static int mkdir_p(const char *path, unsigned long mode)
481 {
482 /* path points to cache entries, so xstrdup before messing with it */
483 char *buf = xstrdup(path);
484 int result = safe_create_leading_directories(buf);
485 free(buf);
486 return result;
487 }
489 static void flush_buffer(int fd, const char *buf, unsigned long size)
490 {
491 while (size > 0) {
492 long ret = write_in_full(fd, buf, size);
493 if (ret < 0) {
494 /* Ignore epipe */
495 if (errno == EPIPE)
496 break;
497 die("merge-recursive: %s", strerror(errno));
498 } else if (!ret) {
499 die("merge-recursive: disk full?");
500 }
501 size -= ret;
502 buf += ret;
503 }
504 }
506 static int make_room_for_path(const char *path)
507 {
508 int status;
509 const char *msg = "failed to create path '%s'%s";
511 status = mkdir_p(path, 0777);
512 if (status) {
513 if (status == -3) {
514 /* something else exists */
515 error(msg, path, ": perhaps a D/F conflict?");
516 return -1;
517 }
518 die(msg, path, "");
519 }
521 /* Successful unlink is good.. */
522 if (!unlink(path))
523 return 0;
524 /* .. and so is no existing file */
525 if (errno == ENOENT)
526 return 0;
527 /* .. but not some other error (who really cares what?) */
528 return error(msg, path, ": perhaps a D/F conflict?");
529 }
531 static void update_file_flags(const unsigned char *sha,
532 unsigned mode,
533 const char *path,
534 int update_cache,
535 int update_wd)
536 {
537 if (index_only)
538 update_wd = 0;
540 if (update_wd) {
541 enum object_type type;
542 void *buf;
543 unsigned long size;
545 if (S_ISGITLINK(mode))
546 die("cannot read object %s '%s': It is a submodule!",
547 sha1_to_hex(sha), path);
549 buf = read_sha1_file(sha, &type, &size);
550 if (!buf)
551 die("cannot read object %s '%s'", sha1_to_hex(sha), path);
552 if (type != OBJ_BLOB)
553 die("blob expected for %s '%s'", sha1_to_hex(sha), path);
555 if (make_room_for_path(path) < 0) {
556 update_wd = 0;
557 goto update_index;
558 }
559 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
560 int fd;
561 if (mode & 0100)
562 mode = 0777;
563 else
564 mode = 0666;
565 fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
566 if (fd < 0)
567 die("failed to open %s: %s", path, strerror(errno));
568 flush_buffer(fd, buf, size);
569 close(fd);
570 } else if (S_ISLNK(mode)) {
571 char *lnk = xmemdupz(buf, size);
572 mkdir_p(path, 0777);
573 unlink(path);
574 symlink(lnk, path);
575 free(lnk);
576 } else
577 die("do not know what to do with %06o %s '%s'",
578 mode, sha1_to_hex(sha), path);
579 }
580 update_index:
581 if (update_cache)
582 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
583 }
585 static void update_file(int clean,
586 const unsigned char *sha,
587 unsigned mode,
588 const char *path)
589 {
590 update_file_flags(sha, mode, path, index_only || clean, !index_only);
591 }
593 /* Low level file merging, update and removal */
595 struct merge_file_info
596 {
597 unsigned char sha[20];
598 unsigned mode;
599 unsigned clean:1,
600 merge:1;
601 };
603 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
604 {
605 unsigned long size;
606 enum object_type type;
608 if (!hashcmp(sha1, null_sha1)) {
609 mm->ptr = xstrdup("");
610 mm->size = 0;
611 return;
612 }
614 mm->ptr = read_sha1_file(sha1, &type, &size);
615 if (!mm->ptr || type != OBJ_BLOB)
616 die("unable to read blob object %s", sha1_to_hex(sha1));
617 mm->size = size;
618 }
620 static int merge_3way(mmbuffer_t *result_buf,
621 struct diff_filespec *o,
622 struct diff_filespec *a,
623 struct diff_filespec *b,
624 const char *branch1,
625 const char *branch2)
626 {
627 mmfile_t orig, src1, src2;
628 char *name1, *name2;
629 int merge_status;
631 name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
632 name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
634 fill_mm(o->sha1, &orig);
635 fill_mm(a->sha1, &src1);
636 fill_mm(b->sha1, &src2);
638 merge_status = ll_merge(result_buf, a->path, &orig,
639 &src1, name1, &src2, name2,
640 index_only);
642 free(name1);
643 free(name2);
644 free(orig.ptr);
645 free(src1.ptr);
646 free(src2.ptr);
647 return merge_status;
648 }
650 static struct merge_file_info merge_file(struct diff_filespec *o,
651 struct diff_filespec *a, struct diff_filespec *b,
652 const char *branch1, const char *branch2)
653 {
654 struct merge_file_info result;
655 result.merge = 0;
656 result.clean = 1;
658 if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
659 result.clean = 0;
660 if (S_ISREG(a->mode)) {
661 result.mode = a->mode;
662 hashcpy(result.sha, a->sha1);
663 } else {
664 result.mode = b->mode;
665 hashcpy(result.sha, b->sha1);
666 }
667 } else {
668 if (!sha_eq(a->sha1, o->sha1) && !sha_eq(b->sha1, o->sha1))
669 result.merge = 1;
671 result.mode = a->mode == o->mode ? b->mode: a->mode;
673 if (sha_eq(a->sha1, o->sha1))
674 hashcpy(result.sha, b->sha1);
675 else if (sha_eq(b->sha1, o->sha1))
676 hashcpy(result.sha, a->sha1);
677 else if (S_ISREG(a->mode)) {
678 mmbuffer_t result_buf;
679 int merge_status;
681 merge_status = merge_3way(&result_buf, o, a, b,
682 branch1, branch2);
684 if ((merge_status < 0) || !result_buf.ptr)
685 die("Failed to execute internal merge");
687 if (write_sha1_file(result_buf.ptr, result_buf.size,
688 blob_type, result.sha))
689 die("Unable to add %s to database",
690 a->path);
692 free(result_buf.ptr);
693 result.clean = (merge_status == 0);
694 } else if (S_ISGITLINK(a->mode)) {
695 result.clean = 0;
696 hashcpy(result.sha, a->sha1);
697 } else if (S_ISLNK(a->mode)) {
698 hashcpy(result.sha, a->sha1);
700 if (!sha_eq(a->sha1, b->sha1))
701 result.clean = 0;
702 } else {
703 die("unsupported object type in the tree");
704 }
705 }
707 return result;
708 }
710 static void conflict_rename_rename(struct rename *ren1,
711 const char *branch1,
712 struct rename *ren2,
713 const char *branch2)
714 {
715 char *del[2];
716 int delp = 0;
717 const char *ren1_dst = ren1->pair->two->path;
718 const char *ren2_dst = ren2->pair->two->path;
719 const char *dst_name1 = ren1_dst;
720 const char *dst_name2 = ren2_dst;
721 if (path_list_has_path(¤t_directory_set, ren1_dst)) {
722 dst_name1 = del[delp++] = unique_path(ren1_dst, branch1);
723 output(1, "%s is a directory in %s added as %s instead",
724 ren1_dst, branch2, dst_name1);
725 remove_file(0, ren1_dst, 0);
726 }
727 if (path_list_has_path(¤t_directory_set, ren2_dst)) {
728 dst_name2 = del[delp++] = unique_path(ren2_dst, branch2);
729 output(1, "%s is a directory in %s added as %s instead",
730 ren2_dst, branch1, dst_name2);
731 remove_file(0, ren2_dst, 0);
732 }
733 if (index_only) {
734 remove_file_from_cache(dst_name1);
735 remove_file_from_cache(dst_name2);
736 /*
737 * Uncomment to leave the conflicting names in the resulting tree
738 *
739 * update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
740 * update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
741 */
742 } else {
743 update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
744 update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
745 }
746 while (delp--)
747 free(del[delp]);
748 }
750 static void conflict_rename_dir(struct rename *ren1,
751 const char *branch1)
752 {
753 char *new_path = unique_path(ren1->pair->two->path, branch1);
754 output(1, "Renamed %s to %s instead", ren1->pair->one->path, new_path);
755 remove_file(0, ren1->pair->two->path, 0);
756 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
757 free(new_path);
758 }
760 static void conflict_rename_rename_2(struct rename *ren1,
761 const char *branch1,
762 struct rename *ren2,
763 const char *branch2)
764 {
765 char *new_path1 = unique_path(ren1->pair->two->path, branch1);
766 char *new_path2 = unique_path(ren2->pair->two->path, branch2);
767 output(1, "Renamed %s to %s and %s to %s instead",
768 ren1->pair->one->path, new_path1,
769 ren2->pair->one->path, new_path2);
770 remove_file(0, ren1->pair->two->path, 0);
771 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
772 update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
773 free(new_path2);
774 free(new_path1);
775 }
777 static int process_renames(struct path_list *a_renames,
778 struct path_list *b_renames,
779 const char *a_branch,
780 const char *b_branch)
781 {
782 int clean_merge = 1, i, j;
783 struct path_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
784 const struct rename *sre;
786 for (i = 0; i < a_renames->nr; i++) {
787 sre = a_renames->items[i].util;
788 path_list_insert(sre->pair->two->path, &a_by_dst)->util
789 = sre->dst_entry;
790 }
791 for (i = 0; i < b_renames->nr; i++) {
792 sre = b_renames->items[i].util;
793 path_list_insert(sre->pair->two->path, &b_by_dst)->util
794 = sre->dst_entry;
795 }
797 for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
798 int compare;
799 char *src;
800 struct path_list *renames1, *renames2, *renames2Dst;
801 struct rename *ren1 = NULL, *ren2 = NULL;
802 const char *branch1, *branch2;
803 const char *ren1_src, *ren1_dst;
805 if (i >= a_renames->nr) {
806 compare = 1;
807 ren2 = b_renames->items[j++].util;
808 } else if (j >= b_renames->nr) {
809 compare = -1;
810 ren1 = a_renames->items[i++].util;
811 } else {
812 compare = strcmp(a_renames->items[i].path,
813 b_renames->items[j].path);
814 if (compare <= 0)
815 ren1 = a_renames->items[i++].util;
816 if (compare >= 0)
817 ren2 = b_renames->items[j++].util;
818 }
820 /* TODO: refactor, so that 1/2 are not needed */
821 if (ren1) {
822 renames1 = a_renames;
823 renames2 = b_renames;
824 renames2Dst = &b_by_dst;
825 branch1 = a_branch;
826 branch2 = b_branch;
827 } else {
828 struct rename *tmp;
829 renames1 = b_renames;
830 renames2 = a_renames;
831 renames2Dst = &a_by_dst;
832 branch1 = b_branch;
833 branch2 = a_branch;
834 tmp = ren2;
835 ren2 = ren1;
836 ren1 = tmp;
837 }
838 src = ren1->pair->one->path;
840 ren1->dst_entry->processed = 1;
841 ren1->src_entry->processed = 1;
843 if (ren1->processed)
844 continue;
845 ren1->processed = 1;
847 ren1_src = ren1->pair->one->path;
848 ren1_dst = ren1->pair->two->path;
850 if (ren2) {
851 const char *ren2_src = ren2->pair->one->path;
852 const char *ren2_dst = ren2->pair->two->path;
853 /* Renamed in 1 and renamed in 2 */
854 if (strcmp(ren1_src, ren2_src) != 0)
855 die("ren1.src != ren2.src");
856 ren2->dst_entry->processed = 1;
857 ren2->processed = 1;
858 if (strcmp(ren1_dst, ren2_dst) != 0) {
859 clean_merge = 0;
860 output(1, "CONFLICT (rename/rename): "
861 "Rename \"%s\"->\"%s\" in branch \"%s\" "
862 "rename \"%s\"->\"%s\" in \"%s\"%s",
863 src, ren1_dst, branch1,
864 src, ren2_dst, branch2,
865 index_only ? " (left unresolved)": "");
866 if (index_only) {
867 remove_file_from_cache(src);
868 update_file(0, ren1->pair->one->sha1,
869 ren1->pair->one->mode, src);
870 }
871 conflict_rename_rename(ren1, branch1, ren2, branch2);
872 } else {
873 struct merge_file_info mfi;
874 remove_file(1, ren1_src, 1);
875 mfi = merge_file(ren1->pair->one,
876 ren1->pair->two,
877 ren2->pair->two,
878 branch1,
879 branch2);
880 if (mfi.merge || !mfi.clean)
881 output(1, "Renamed %s->%s", src, ren1_dst);
883 if (mfi.merge)
884 output(2, "Auto-merged %s", ren1_dst);
886 if (!mfi.clean) {
887 output(1, "CONFLICT (content): merge conflict in %s",
888 ren1_dst);
889 clean_merge = 0;
891 if (!index_only)
892 update_stages(ren1_dst,
893 ren1->pair->one,
894 ren1->pair->two,
895 ren2->pair->two,
896 1 /* clear */);
897 }
898 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
899 }
900 } else {
901 /* Renamed in 1, maybe changed in 2 */
902 struct path_list_item *item;
903 /* we only use sha1 and mode of these */
904 struct diff_filespec src_other, dst_other;
905 int try_merge, stage = a_renames == renames1 ? 3: 2;
907 remove_file(1, ren1_src, index_only || stage == 3);
909 hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
910 src_other.mode = ren1->src_entry->stages[stage].mode;
911 hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
912 dst_other.mode = ren1->dst_entry->stages[stage].mode;
914 try_merge = 0;
916 if (path_list_has_path(¤t_directory_set, ren1_dst)) {
917 clean_merge = 0;
918 output(1, "CONFLICT (rename/directory): Renamed %s->%s in %s "
919 " directory %s added in %s",
920 ren1_src, ren1_dst, branch1,
921 ren1_dst, branch2);
922 conflict_rename_dir(ren1, branch1);
923 } else if (sha_eq(src_other.sha1, null_sha1)) {
924 clean_merge = 0;
925 output(1, "CONFLICT (rename/delete): Renamed %s->%s in %s "
926 "and deleted in %s",
927 ren1_src, ren1_dst, branch1,
928 branch2);
929 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
930 } else if (!sha_eq(dst_other.sha1, null_sha1)) {
931 const char *new_path;
932 clean_merge = 0;
933 try_merge = 1;
934 output(1, "CONFLICT (rename/add): Renamed %s->%s in %s. "
935 "%s added in %s",
936 ren1_src, ren1_dst, branch1,
937 ren1_dst, branch2);
938 new_path = unique_path(ren1_dst, branch2);
939 output(1, "Added as %s instead", new_path);
940 update_file(0, dst_other.sha1, dst_other.mode, new_path);
941 } else if ((item = path_list_lookup(ren1_dst, renames2Dst))) {
942 ren2 = item->util;
943 clean_merge = 0;
944 ren2->processed = 1;
945 output(1, "CONFLICT (rename/rename): Renamed %s->%s in %s. "
946 "Renamed %s->%s in %s",
947 ren1_src, ren1_dst, branch1,
948 ren2->pair->one->path, ren2->pair->two->path, branch2);
949 conflict_rename_rename_2(ren1, branch1, ren2, branch2);
950 } else
951 try_merge = 1;
953 if (try_merge) {
954 struct diff_filespec *o, *a, *b;
955 struct merge_file_info mfi;
956 src_other.path = (char *)ren1_src;
958 o = ren1->pair->one;
959 if (a_renames == renames1) {
960 a = ren1->pair->two;
961 b = &src_other;
962 } else {
963 b = ren1->pair->two;
964 a = &src_other;
965 }
966 mfi = merge_file(o, a, b,
967 a_branch, b_branch);
969 if (mfi.clean &&
970 sha_eq(mfi.sha, ren1->pair->two->sha1) &&
971 mfi.mode == ren1->pair->two->mode)
972 /*
973 * This messaged is part of
974 * t6022 test. If you change
975 * it update the test too.
976 */
977 output(3, "Skipped %s (merged same as existing)", ren1_dst);
978 else {
979 if (mfi.merge || !mfi.clean)
980 output(1, "Renamed %s => %s", ren1_src, ren1_dst);
981 if (mfi.merge)
982 output(2, "Auto-merged %s", ren1_dst);
983 if (!mfi.clean) {
984 output(1, "CONFLICT (rename/modify): Merge conflict in %s",
985 ren1_dst);
986 clean_merge = 0;
988 if (!index_only)
989 update_stages(ren1_dst,
990 o, a, b, 1);
991 }
992 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
993 }
994 }
995 }
996 }
997 path_list_clear(&a_by_dst, 0);
998 path_list_clear(&b_by_dst, 0);
1000 return clean_merge;
1001 }
1003 static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1004 {
1005 return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1006 }
1008 /* Per entry merge function */
1009 static int process_entry(const char *path, struct stage_data *entry,
1010 const char *branch1,
1011 const char *branch2)
1012 {
1013 /*
1014 printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1015 print_index_entry("\tpath: ", entry);
1016 */
1017 int clean_merge = 1;
1018 unsigned o_mode = entry->stages[1].mode;
1019 unsigned a_mode = entry->stages[2].mode;
1020 unsigned b_mode = entry->stages[3].mode;
1021 unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1022 unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1023 unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1025 if (o_sha && (!a_sha || !b_sha)) {
1026 /* Case A: Deleted in one */
1027 if ((!a_sha && !b_sha) ||
1028 (sha_eq(a_sha, o_sha) && !b_sha) ||
1029 (!a_sha && sha_eq(b_sha, o_sha))) {
1030 /* Deleted in both or deleted in one and
1031 * unchanged in the other */
1032 if (a_sha)
1033 output(2, "Removed %s", path);
1034 /* do not touch working file if it did not exist */
1035 remove_file(1, path, !a_sha);
1036 } else {
1037 /* Deleted in one and changed in the other */
1038 clean_merge = 0;
1039 if (!a_sha) {
1040 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1041 "and modified in %s. Version %s of %s left in tree.",
1042 path, branch1,
1043 branch2, branch2, path);
1044 update_file(0, b_sha, b_mode, path);
1045 } else {
1046 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1047 "and modified in %s. Version %s of %s left in tree.",
1048 path, branch2,
1049 branch1, branch1, path);
1050 update_file(0, a_sha, a_mode, path);
1051 }
1052 }
1054 } else if ((!o_sha && a_sha && !b_sha) ||
1055 (!o_sha && !a_sha && b_sha)) {
1056 /* Case B: Added in one. */
1057 const char *add_branch;
1058 const char *other_branch;
1059 unsigned mode;
1060 const unsigned char *sha;
1061 const char *conf;
1063 if (a_sha) {
1064 add_branch = branch1;
1065 other_branch = branch2;
1066 mode = a_mode;
1067 sha = a_sha;
1068 conf = "file/directory";
1069 } else {
1070 add_branch = branch2;
1071 other_branch = branch1;
1072 mode = b_mode;
1073 sha = b_sha;
1074 conf = "directory/file";
1075 }
1076 if (path_list_has_path(¤t_directory_set, path)) {
1077 const char *new_path = unique_path(path, add_branch);
1078 clean_merge = 0;
1079 output(1, "CONFLICT (%s): There is a directory with name %s in %s. "
1080 "Added %s as %s",
1081 conf, path, other_branch, path, new_path);
1082 remove_file(0, path, 0);
1083 update_file(0, sha, mode, new_path);
1084 } else {
1085 output(2, "Added %s", path);
1086 update_file(1, sha, mode, path);
1087 }
1088 } else if (a_sha && b_sha) {
1089 /* Case C: Added in both (check for same permissions) and */
1090 /* case D: Modified in both, but differently. */
1091 const char *reason = "content";
1092 struct merge_file_info mfi;
1093 struct diff_filespec o, a, b;
1095 if (!o_sha) {
1096 reason = "add/add";
1097 o_sha = (unsigned char *)null_sha1;
1098 }
1099 output(2, "Auto-merged %s", path);
1100 o.path = a.path = b.path = (char *)path;
1101 hashcpy(o.sha1, o_sha);
1102 o.mode = o_mode;
1103 hashcpy(a.sha1, a_sha);
1104 a.mode = a_mode;
1105 hashcpy(b.sha1, b_sha);
1106 b.mode = b_mode;
1108 mfi = merge_file(&o, &a, &b,
1109 branch1, branch2);
1111 clean_merge = mfi.clean;
1112 if (mfi.clean)
1113 update_file(1, mfi.sha, mfi.mode, path);
1114 else if (S_ISGITLINK(mfi.mode))
1115 output(1, "CONFLICT (submodule): Merge conflict in %s "
1116 "- needs %s", path, sha1_to_hex(b.sha1));
1117 else {
1118 output(1, "CONFLICT (%s): Merge conflict in %s",
1119 reason, path);
1121 if (index_only)
1122 update_file(0, mfi.sha, mfi.mode, path);
1123 else
1124 update_file_flags(mfi.sha, mfi.mode, path,
1125 0 /* update_cache */, 1 /* update_working_directory */);
1126 }
1127 } else if (!o_sha && !a_sha && !b_sha) {
1128 /*
1129 * this entry was deleted altogether. a_mode == 0 means
1130 * we had that path and want to actively remove it.
1131 */
1132 remove_file(1, path, !a_mode);
1133 } else
1134 die("Fatal merge failure, shouldn't happen.");
1136 return clean_merge;
1137 }
1139 int merge_trees(struct tree *head,
1140 struct tree *merge,
1141 struct tree *common,
1142 const char *branch1,
1143 const char *branch2,
1144 struct tree **result)
1145 {
1146 int code, clean;
1148 if (subtree_merge) {
1149 merge = shift_tree_object(head, merge);
1150 common = shift_tree_object(head, common);
1151 }
1153 if (sha_eq(common->object.sha1, merge->object.sha1)) {
1154 output(0, "Already uptodate!");
1155 *result = head;
1156 return 1;
1157 }
1159 code = git_merge_trees(index_only, common, head, merge);
1161 if (code != 0)
1162 die("merging of trees %s and %s failed",
1163 sha1_to_hex(head->object.sha1),
1164 sha1_to_hex(merge->object.sha1));
1166 if (unmerged_cache()) {
1167 struct path_list *entries, *re_head, *re_merge;
1168 int i;
1169 path_list_clear(¤t_file_set, 1);
1170 path_list_clear(¤t_directory_set, 1);
1171 get_files_dirs(head);
1172 get_files_dirs(merge);
1174 entries = get_unmerged();
1175 re_head = get_renames(head, common, head, merge, entries);
1176 re_merge = get_renames(merge, common, head, merge, entries);
1177 clean = process_renames(re_head, re_merge,
1178 branch1, branch2);
1179 for (i = 0; i < entries->nr; i++) {
1180 const char *path = entries->items[i].path;
1181 struct stage_data *e = entries->items[i].util;
1182 if (!e->processed
1183 && !process_entry(path, e, branch1, branch2))
1184 clean = 0;
1185 }
1187 path_list_clear(re_merge, 0);
1188 path_list_clear(re_head, 0);
1189 path_list_clear(entries, 1);
1191 }
1192 else
1193 clean = 1;
1195 if (index_only)
1196 *result = write_tree_from_memory();
1198 return clean;
1199 }
1201 static struct commit_list *reverse_commit_list(struct commit_list *list)
1202 {
1203 struct commit_list *next = NULL, *current, *backup;
1204 for (current = list; current; current = backup) {
1205 backup = current->next;
1206 current->next = next;
1207 next = current;
1208 }
1209 return next;
1210 }
1212 /*
1213 * Merge the commits h1 and h2, return the resulting virtual
1214 * commit object and a flag indicating the cleanness of the merge.
1215 */
1216 int merge_recursive(struct commit *h1,
1217 struct commit *h2,
1218 const char *branch1,
1219 const char *branch2,
1220 struct commit_list *ca,
1221 struct commit **result)
1222 {
1223 struct commit_list *iter;
1224 struct commit *merged_common_ancestors;
1225 struct tree *mrtree = mrtree;
1226 int clean;
1228 if (show(4)) {
1229 output(4, "Merging:");
1230 output_commit_title(h1);
1231 output_commit_title(h2);
1232 }
1234 if (!ca) {
1235 ca = get_merge_bases(h1, h2, 1);
1236 ca = reverse_commit_list(ca);
1237 }
1239 if (show(5)) {
1240 output(5, "found %u common ancestor(s):", commit_list_count(ca));
1241 for (iter = ca; iter; iter = iter->next)
1242 output_commit_title(iter->item);
1243 }
1245 merged_common_ancestors = pop_commit(&ca);
1246 if (merged_common_ancestors == NULL) {
1247 /* if there is no common ancestor, make an empty tree */
1248 struct tree *tree = xcalloc(1, sizeof(struct tree));
1250 tree->object.parsed = 1;
1251 tree->object.type = OBJ_TREE;
1252 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1253 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1254 }
1256 for (iter = ca; iter; iter = iter->next) {
1257 call_depth++;
1258 /*
1259 * When the merge fails, the result contains files
1260 * with conflict markers. The cleanness flag is
1261 * ignored, it was never actually used, as result of
1262 * merge_trees has always overwritten it: the committed
1263 * "conflicts" were already resolved.
1264 */
1265 discard_cache();
1266 merge_recursive(merged_common_ancestors, iter->item,
1267 "Temporary merge branch 1",
1268 "Temporary merge branch 2",
1269 NULL,
1270 &merged_common_ancestors);
1271 call_depth--;
1273 if (!merged_common_ancestors)
1274 die("merge returned no commit");
1275 }
1277 discard_cache();
1278 if (!call_depth) {
1279 read_cache();
1280 index_only = 0;
1281 } else
1282 index_only = 1;
1284 clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
1285 branch1, branch2, &mrtree);
1287 if (index_only) {
1288 *result = make_virtual_commit(mrtree, "merged tree");
1289 commit_list_insert(h1, &(*result)->parents);
1290 commit_list_insert(h2, &(*result)->parents->next);
1291 }
1292 flush_output();
1293 return clean;
1294 }
1296 static const char *better_branch_name(const char *branch)
1297 {
1298 static char githead_env[8 + 40 + 1];
1299 char *name;
1301 if (strlen(branch) != 40)
1302 return branch;
1303 sprintf(githead_env, "GITHEAD_%s", branch);
1304 name = getenv(githead_env);
1305 return name ? name : branch;
1306 }
1308 static struct commit *get_ref(const char *ref)
1309 {
1310 unsigned char sha1[20];
1311 struct object *object;
1313 if (get_sha1(ref, sha1))
1314 die("Could not resolve ref '%s'", ref);
1315 object = deref_tag(parse_object(sha1), ref, strlen(ref));
1316 if (!object)
1317 return NULL;
1318 if (object->type == OBJ_TREE)
1319 return make_virtual_commit((struct tree*)object,
1320 better_branch_name(ref));
1321 if (object->type != OBJ_COMMIT)
1322 return NULL;
1323 if (parse_commit((struct commit *)object))
1324 die("Could not parse commit '%s'", sha1_to_hex(object->sha1));
1325 return (struct commit *)object;
1326 }
1328 static int merge_config(const char *var, const char *value)
1329 {
1330 if (!strcasecmp(var, "merge.verbosity")) {
1331 verbosity = git_config_int(var, value);
1332 return 0;
1333 }
1334 if (!strcasecmp(var, "diff.renamelimit")) {
1335 rename_limit = git_config_int(var, value);
1336 return 0;
1337 }
1338 return git_default_config(var, value);
1339 }
1341 int cmd_merge_recursive(int argc, const char **argv, const char *prefix)
1342 {
1343 static const char *bases[20];
1344 static unsigned bases_count = 0;
1345 int i, clean;
1346 const char *branch1, *branch2;
1347 struct commit *result, *h1, *h2;
1348 struct commit_list *ca = NULL;
1349 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1350 int index_fd;
1352 if (argv[0]) {
1353 int namelen = strlen(argv[0]);
1354 if (8 < namelen &&
1355 !strcmp(argv[0] + namelen - 8, "-subtree"))
1356 subtree_merge = 1;
1357 }
1359 git_config(merge_config);
1360 if (getenv("GIT_MERGE_VERBOSITY"))
1361 verbosity = strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1363 if (argc < 4)
1364 die("Usage: %s <base>... -- <head> <remote> ...\n", argv[0]);
1366 for (i = 1; i < argc; ++i) {
1367 if (!strcmp(argv[i], "--"))
1368 break;
1369 if (bases_count < sizeof(bases)/sizeof(*bases))
1370 bases[bases_count++] = argv[i];
1371 }
1372 if (argc - i != 3) /* "--" "<head>" "<remote>" */
1373 die("Not handling anything other than two heads merge.");
1374 if (verbosity >= 5)
1375 buffer_output = 0;
1377 branch1 = argv[++i];
1378 branch2 = argv[++i];
1380 h1 = get_ref(branch1);
1381 h2 = get_ref(branch2);
1383 branch1 = better_branch_name(branch1);
1384 branch2 = better_branch_name(branch2);
1386 if (show(3))
1387 printf("Merging %s with %s\n", branch1, branch2);
1389 index_fd = hold_locked_index(lock, 1);
1391 for (i = 0; i < bases_count; i++) {
1392 struct commit *ancestor = get_ref(bases[i]);
1393 ca = commit_list_insert(ancestor, &ca);
1394 }
1395 clean = merge_recursive(h1, h2, branch1, branch2, ca, &result);
1397 if (active_cache_changed &&
1398 (write_cache(index_fd, active_cache, active_nr) ||
1399 commit_locked_index(lock)))
1400 die ("unable to write %s", get_index_file());
1402 return clean ? 0: 1;
1403 }