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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 "string-list.h"
17 #include "xdiff-interface.h"
18 #include "ll-merge.h"
19 #include "attr.h"
20 #include "merge-recursive.h"
21 #include "dir.h"
23 static struct tree *shift_tree_object(struct tree *one, struct tree *two)
24 {
25 unsigned char shifted[20];
27 /*
28 * NEEDSWORK: this limits the recursion depth to hardcoded
29 * value '2' to avoid excessive overhead.
30 */
31 shift_tree(one->object.sha1, two->object.sha1, shifted, 2);
32 if (!hashcmp(two->object.sha1, shifted))
33 return two;
34 return lookup_tree(shifted);
35 }
37 /*
38 * A virtual commit has (const char *)commit->util set to the name.
39 */
41 struct commit *make_virtual_commit(struct tree *tree, const char *comment)
42 {
43 struct commit *commit = xcalloc(1, sizeof(struct commit));
44 commit->tree = tree;
45 commit->util = (void*)comment;
46 /* avoid warnings */
47 commit->object.parsed = 1;
48 return commit;
49 }
51 /*
52 * Since we use get_tree_entry(), which does not put the read object into
53 * the object pool, we cannot rely on a == b.
54 */
55 static int sha_eq(const unsigned char *a, const unsigned char *b)
56 {
57 if (!a && !b)
58 return 2;
59 return a && b && hashcmp(a, b) == 0;
60 }
62 /*
63 * Since we want to write the index eventually, we cannot reuse the index
64 * for these (temporary) data.
65 */
66 struct stage_data
67 {
68 struct
69 {
70 unsigned mode;
71 unsigned char sha[20];
72 } stages[4];
73 unsigned processed:1;
74 };
76 static int show(struct merge_options *o, int v)
77 {
78 return (!o->call_depth && o->verbosity >= v) || o->verbosity >= 5;
79 }
81 static void flush_output(struct merge_options *o)
82 {
83 if (o->obuf.len) {
84 fputs(o->obuf.buf, stdout);
85 strbuf_reset(&o->obuf);
86 }
87 }
89 static void output(struct merge_options *o, int v, const char *fmt, ...)
90 {
91 int len;
92 va_list ap;
94 if (!show(o, v))
95 return;
97 strbuf_grow(&o->obuf, o->call_depth * 2 + 2);
98 memset(o->obuf.buf + o->obuf.len, ' ', o->call_depth * 2);
99 strbuf_setlen(&o->obuf, o->obuf.len + o->call_depth * 2);
101 va_start(ap, fmt);
102 len = vsnprintf(o->obuf.buf + o->obuf.len, strbuf_avail(&o->obuf), fmt, ap);
103 va_end(ap);
105 if (len < 0)
106 len = 0;
107 if (len >= strbuf_avail(&o->obuf)) {
108 strbuf_grow(&o->obuf, len + 2);
109 va_start(ap, fmt);
110 len = vsnprintf(o->obuf.buf + o->obuf.len, strbuf_avail(&o->obuf), fmt, ap);
111 va_end(ap);
112 if (len >= strbuf_avail(&o->obuf)) {
113 die("this should not happen, your snprintf is broken");
114 }
115 }
116 strbuf_setlen(&o->obuf, o->obuf.len + len);
117 strbuf_add(&o->obuf, "\n", 1);
118 if (!o->buffer_output)
119 flush_output(o);
120 }
122 static void output_commit_title(struct merge_options *o, struct commit *commit)
123 {
124 int i;
125 flush_output(o);
126 for (i = o->call_depth; i--;)
127 fputs(" ", stdout);
128 if (commit->util)
129 printf("virtual %s\n", (char *)commit->util);
130 else {
131 printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
132 if (parse_commit(commit) != 0)
133 printf("(bad commit)\n");
134 else {
135 const char *s;
136 int len;
137 for (s = commit->buffer; *s; s++)
138 if (*s == '\n' && s[1] == '\n') {
139 s += 2;
140 break;
141 }
142 for (len = 0; s[len] && '\n' != s[len]; len++)
143 ; /* do nothing */
144 printf("%.*s\n", len, s);
145 }
146 }
147 }
149 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
150 const char *path, int stage, int refresh, int options)
151 {
152 struct cache_entry *ce;
153 ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
154 if (!ce)
155 return error("addinfo_cache failed for path '%s'", path);
156 return add_cache_entry(ce, options);
157 }
159 static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
160 {
161 parse_tree(tree);
162 init_tree_desc(desc, tree->buffer, tree->size);
163 }
165 static int git_merge_trees(int index_only,
166 struct tree *common,
167 struct tree *head,
168 struct tree *merge)
169 {
170 int rc;
171 struct tree_desc t[3];
172 struct unpack_trees_options opts;
174 memset(&opts, 0, sizeof(opts));
175 if (index_only)
176 opts.index_only = 1;
177 else
178 opts.update = 1;
179 opts.merge = 1;
180 opts.head_idx = 2;
181 opts.fn = threeway_merge;
182 opts.src_index = &the_index;
183 opts.dst_index = &the_index;
185 init_tree_desc_from_tree(t+0, common);
186 init_tree_desc_from_tree(t+1, head);
187 init_tree_desc_from_tree(t+2, merge);
189 rc = unpack_trees(3, t, &opts);
190 cache_tree_free(&active_cache_tree);
191 return rc;
192 }
194 struct tree *write_tree_from_memory(struct merge_options *o)
195 {
196 struct tree *result = NULL;
198 if (unmerged_cache()) {
199 int i;
200 output(o, 0, "There are unmerged index entries:");
201 for (i = 0; i < active_nr; i++) {
202 struct cache_entry *ce = active_cache[i];
203 if (ce_stage(ce))
204 output(o, 0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
205 }
206 return NULL;
207 }
209 if (!active_cache_tree)
210 active_cache_tree = cache_tree();
212 if (!cache_tree_fully_valid(active_cache_tree) &&
213 cache_tree_update(active_cache_tree,
214 active_cache, active_nr, 0, 0) < 0)
215 die("error building trees");
217 result = lookup_tree(active_cache_tree->sha1);
219 return result;
220 }
222 static int save_files_dirs(const unsigned char *sha1,
223 const char *base, int baselen, const char *path,
224 unsigned int mode, int stage, void *context)
225 {
226 int len = strlen(path);
227 char *newpath = xmalloc(baselen + len + 1);
228 struct merge_options *o = context;
230 memcpy(newpath, base, baselen);
231 memcpy(newpath + baselen, path, len);
232 newpath[baselen + len] = '\0';
234 if (S_ISDIR(mode))
235 string_list_insert(newpath, &o->current_directory_set);
236 else
237 string_list_insert(newpath, &o->current_file_set);
238 free(newpath);
240 return READ_TREE_RECURSIVE;
241 }
243 static int get_files_dirs(struct merge_options *o, struct tree *tree)
244 {
245 int n;
246 if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs, o))
247 return 0;
248 n = o->current_file_set.nr + o->current_directory_set.nr;
249 return n;
250 }
252 /*
253 * Returns an index_entry instance which doesn't have to correspond to
254 * a real cache entry in Git's index.
255 */
256 static struct stage_data *insert_stage_data(const char *path,
257 struct tree *o, struct tree *a, struct tree *b,
258 struct string_list *entries)
259 {
260 struct string_list_item *item;
261 struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
262 get_tree_entry(o->object.sha1, path,
263 e->stages[1].sha, &e->stages[1].mode);
264 get_tree_entry(a->object.sha1, path,
265 e->stages[2].sha, &e->stages[2].mode);
266 get_tree_entry(b->object.sha1, path,
267 e->stages[3].sha, &e->stages[3].mode);
268 item = string_list_insert(path, entries);
269 item->util = e;
270 return e;
271 }
273 /*
274 * Create a dictionary mapping file names to stage_data objects. The
275 * dictionary contains one entry for every path with a non-zero stage entry.
276 */
277 static struct string_list *get_unmerged(void)
278 {
279 struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
280 int i;
282 unmerged->strdup_strings = 1;
284 for (i = 0; i < active_nr; i++) {
285 struct string_list_item *item;
286 struct stage_data *e;
287 struct cache_entry *ce = active_cache[i];
288 if (!ce_stage(ce))
289 continue;
291 item = string_list_lookup(ce->name, unmerged);
292 if (!item) {
293 item = string_list_insert(ce->name, unmerged);
294 item->util = xcalloc(1, sizeof(struct stage_data));
295 }
296 e = item->util;
297 e->stages[ce_stage(ce)].mode = ce->ce_mode;
298 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
299 }
301 return unmerged;
302 }
304 struct rename
305 {
306 struct diff_filepair *pair;
307 struct stage_data *src_entry;
308 struct stage_data *dst_entry;
309 unsigned processed:1;
310 };
312 /*
313 * Get information of all renames which occurred between 'o_tree' and
314 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
315 * 'b_tree') to be able to associate the correct cache entries with
316 * the rename information. 'tree' is always equal to either a_tree or b_tree.
317 */
318 static struct string_list *get_renames(struct merge_options *o,
319 struct tree *tree,
320 struct tree *o_tree,
321 struct tree *a_tree,
322 struct tree *b_tree,
323 struct string_list *entries)
324 {
325 int i;
326 struct string_list *renames;
327 struct diff_options opts;
329 renames = xcalloc(1, sizeof(struct string_list));
330 diff_setup(&opts);
331 DIFF_OPT_SET(&opts, RECURSIVE);
332 opts.detect_rename = DIFF_DETECT_RENAME;
333 opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
334 o->diff_rename_limit >= 0 ? o->diff_rename_limit :
335 500;
336 opts.warn_on_too_large_rename = 1;
337 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
338 if (diff_setup_done(&opts) < 0)
339 die("diff setup failed");
340 diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
341 diffcore_std(&opts);
342 for (i = 0; i < diff_queued_diff.nr; ++i) {
343 struct string_list_item *item;
344 struct rename *re;
345 struct diff_filepair *pair = diff_queued_diff.queue[i];
346 if (pair->status != 'R') {
347 diff_free_filepair(pair);
348 continue;
349 }
350 re = xmalloc(sizeof(*re));
351 re->processed = 0;
352 re->pair = pair;
353 item = string_list_lookup(re->pair->one->path, entries);
354 if (!item)
355 re->src_entry = insert_stage_data(re->pair->one->path,
356 o_tree, a_tree, b_tree, entries);
357 else
358 re->src_entry = item->util;
360 item = string_list_lookup(re->pair->two->path, entries);
361 if (!item)
362 re->dst_entry = insert_stage_data(re->pair->two->path,
363 o_tree, a_tree, b_tree, entries);
364 else
365 re->dst_entry = item->util;
366 item = string_list_insert(pair->one->path, renames);
367 item->util = re;
368 }
369 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
370 diff_queued_diff.nr = 0;
371 diff_flush(&opts);
372 return renames;
373 }
375 static int update_stages(const char *path, struct diff_filespec *o,
376 struct diff_filespec *a, struct diff_filespec *b,
377 int clear)
378 {
379 int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
380 if (clear)
381 if (remove_file_from_cache(path))
382 return -1;
383 if (o)
384 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
385 return -1;
386 if (a)
387 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
388 return -1;
389 if (b)
390 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
391 return -1;
392 return 0;
393 }
395 static int remove_file(struct merge_options *o, int clean,
396 const char *path, int no_wd)
397 {
398 int update_cache = o->call_depth || clean;
399 int update_working_directory = !o->call_depth && !no_wd;
401 if (update_cache) {
402 if (remove_file_from_cache(path))
403 return -1;
404 }
405 if (update_working_directory) {
406 if (remove_path(path) && errno != ENOENT)
407 return -1;
408 }
409 return 0;
410 }
412 static char *unique_path(struct merge_options *o, const char *path, const char *branch)
413 {
414 char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
415 int suffix = 0;
416 struct stat st;
417 char *p = newpath + strlen(path);
418 strcpy(newpath, path);
419 *(p++) = '~';
420 strcpy(p, branch);
421 for (; *p; ++p)
422 if ('/' == *p)
423 *p = '_';
424 while (string_list_has_string(&o->current_file_set, newpath) ||
425 string_list_has_string(&o->current_directory_set, newpath) ||
426 lstat(newpath, &st) == 0)
427 sprintf(p, "_%d", suffix++);
429 string_list_insert(newpath, &o->current_file_set);
430 return newpath;
431 }
433 static void flush_buffer(int fd, const char *buf, unsigned long size)
434 {
435 while (size > 0) {
436 long ret = write_in_full(fd, buf, size);
437 if (ret < 0) {
438 /* Ignore epipe */
439 if (errno == EPIPE)
440 break;
441 die("merge-recursive: %s", strerror(errno));
442 } else if (!ret) {
443 die("merge-recursive: disk full?");
444 }
445 size -= ret;
446 buf += ret;
447 }
448 }
450 static int make_room_for_path(const char *path)
451 {
452 int status;
453 const char *msg = "failed to create path '%s'%s";
455 status = safe_create_leading_directories_const(path);
456 if (status) {
457 if (status == -3) {
458 /* something else exists */
459 error(msg, path, ": perhaps a D/F conflict?");
460 return -1;
461 }
462 die(msg, path, "");
463 }
465 /* Successful unlink is good.. */
466 if (!unlink(path))
467 return 0;
468 /* .. and so is no existing file */
469 if (errno == ENOENT)
470 return 0;
471 /* .. but not some other error (who really cares what?) */
472 return error(msg, path, ": perhaps a D/F conflict?");
473 }
475 static void update_file_flags(struct merge_options *o,
476 const unsigned char *sha,
477 unsigned mode,
478 const char *path,
479 int update_cache,
480 int update_wd)
481 {
482 if (o->call_depth)
483 update_wd = 0;
485 if (update_wd) {
486 enum object_type type;
487 void *buf;
488 unsigned long size;
490 if (S_ISGITLINK(mode))
491 die("cannot read object %s '%s': It is a submodule!",
492 sha1_to_hex(sha), path);
494 buf = read_sha1_file(sha, &type, &size);
495 if (!buf)
496 die("cannot read object %s '%s'", sha1_to_hex(sha), path);
497 if (type != OBJ_BLOB)
498 die("blob expected for %s '%s'", sha1_to_hex(sha), path);
499 if (S_ISREG(mode)) {
500 struct strbuf strbuf = STRBUF_INIT;
501 if (convert_to_working_tree(path, buf, size, &strbuf)) {
502 free(buf);
503 size = strbuf.len;
504 buf = strbuf_detach(&strbuf, NULL);
505 }
506 }
508 if (make_room_for_path(path) < 0) {
509 update_wd = 0;
510 free(buf);
511 goto update_index;
512 }
513 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
514 int fd;
515 if (mode & 0100)
516 mode = 0777;
517 else
518 mode = 0666;
519 fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
520 if (fd < 0)
521 die("failed to open %s: %s", path, strerror(errno));
522 flush_buffer(fd, buf, size);
523 close(fd);
524 } else if (S_ISLNK(mode)) {
525 char *lnk = xmemdupz(buf, size);
526 safe_create_leading_directories_const(path);
527 unlink(path);
528 if (symlink(lnk, path))
529 die("failed to symlink %s: %s", path, strerror(errno));
530 free(lnk);
531 } else
532 die("do not know what to do with %06o %s '%s'",
533 mode, sha1_to_hex(sha), path);
534 free(buf);
535 }
536 update_index:
537 if (update_cache)
538 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
539 }
541 static void update_file(struct merge_options *o,
542 int clean,
543 const unsigned char *sha,
544 unsigned mode,
545 const char *path)
546 {
547 update_file_flags(o, sha, mode, path, o->call_depth || clean, !o->call_depth);
548 }
550 /* Low level file merging, update and removal */
552 struct merge_file_info
553 {
554 unsigned char sha[20];
555 unsigned mode;
556 unsigned clean:1,
557 merge:1;
558 };
560 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
561 {
562 unsigned long size;
563 enum object_type type;
565 if (!hashcmp(sha1, null_sha1)) {
566 mm->ptr = xstrdup("");
567 mm->size = 0;
568 return;
569 }
571 mm->ptr = read_sha1_file(sha1, &type, &size);
572 if (!mm->ptr || type != OBJ_BLOB)
573 die("unable to read blob object %s", sha1_to_hex(sha1));
574 mm->size = size;
575 }
577 static int merge_3way(struct merge_options *o,
578 mmbuffer_t *result_buf,
579 struct diff_filespec *one,
580 struct diff_filespec *a,
581 struct diff_filespec *b,
582 const char *branch1,
583 const char *branch2)
584 {
585 mmfile_t orig, src1, src2;
586 char *name1, *name2;
587 int merge_status;
589 name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
590 name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
592 fill_mm(one->sha1, &orig);
593 fill_mm(a->sha1, &src1);
594 fill_mm(b->sha1, &src2);
596 merge_status = ll_merge(result_buf, a->path, &orig,
597 &src1, name1, &src2, name2,
598 o->call_depth);
600 free(name1);
601 free(name2);
602 free(orig.ptr);
603 free(src1.ptr);
604 free(src2.ptr);
605 return merge_status;
606 }
608 static struct merge_file_info merge_file(struct merge_options *o,
609 struct diff_filespec *one,
610 struct diff_filespec *a,
611 struct diff_filespec *b,
612 const char *branch1,
613 const char *branch2)
614 {
615 struct merge_file_info result;
616 result.merge = 0;
617 result.clean = 1;
619 if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
620 result.clean = 0;
621 if (S_ISREG(a->mode)) {
622 result.mode = a->mode;
623 hashcpy(result.sha, a->sha1);
624 } else {
625 result.mode = b->mode;
626 hashcpy(result.sha, b->sha1);
627 }
628 } else {
629 if (!sha_eq(a->sha1, one->sha1) && !sha_eq(b->sha1, one->sha1))
630 result.merge = 1;
632 /*
633 * Merge modes
634 */
635 if (a->mode == b->mode || a->mode == one->mode)
636 result.mode = b->mode;
637 else {
638 result.mode = a->mode;
639 if (b->mode != one->mode) {
640 result.clean = 0;
641 result.merge = 1;
642 }
643 }
645 if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, one->sha1))
646 hashcpy(result.sha, b->sha1);
647 else if (sha_eq(b->sha1, one->sha1))
648 hashcpy(result.sha, a->sha1);
649 else if (S_ISREG(a->mode)) {
650 mmbuffer_t result_buf;
651 int merge_status;
653 merge_status = merge_3way(o, &result_buf, one, a, b,
654 branch1, branch2);
656 if ((merge_status < 0) || !result_buf.ptr)
657 die("Failed to execute internal merge");
659 if (write_sha1_file(result_buf.ptr, result_buf.size,
660 blob_type, result.sha))
661 die("Unable to add %s to database",
662 a->path);
664 free(result_buf.ptr);
665 result.clean = (merge_status == 0);
666 } else if (S_ISGITLINK(a->mode)) {
667 result.clean = 0;
668 hashcpy(result.sha, a->sha1);
669 } else if (S_ISLNK(a->mode)) {
670 hashcpy(result.sha, a->sha1);
672 if (!sha_eq(a->sha1, b->sha1))
673 result.clean = 0;
674 } else {
675 die("unsupported object type in the tree");
676 }
677 }
679 return result;
680 }
682 static void conflict_rename_rename(struct merge_options *o,
683 struct rename *ren1,
684 const char *branch1,
685 struct rename *ren2,
686 const char *branch2)
687 {
688 char *del[2];
689 int delp = 0;
690 const char *ren1_dst = ren1->pair->two->path;
691 const char *ren2_dst = ren2->pair->two->path;
692 const char *dst_name1 = ren1_dst;
693 const char *dst_name2 = ren2_dst;
694 if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
695 dst_name1 = del[delp++] = unique_path(o, ren1_dst, branch1);
696 output(o, 1, "%s is a directory in %s adding as %s instead",
697 ren1_dst, branch2, dst_name1);
698 remove_file(o, 0, ren1_dst, 0);
699 }
700 if (string_list_has_string(&o->current_directory_set, ren2_dst)) {
701 dst_name2 = del[delp++] = unique_path(o, ren2_dst, branch2);
702 output(o, 1, "%s is a directory in %s adding as %s instead",
703 ren2_dst, branch1, dst_name2);
704 remove_file(o, 0, ren2_dst, 0);
705 }
706 if (o->call_depth) {
707 remove_file_from_cache(dst_name1);
708 remove_file_from_cache(dst_name2);
709 /*
710 * Uncomment to leave the conflicting names in the resulting tree
711 *
712 * update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
713 * update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
714 */
715 } else {
716 update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
717 update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
718 }
719 while (delp--)
720 free(del[delp]);
721 }
723 static void conflict_rename_dir(struct merge_options *o,
724 struct rename *ren1,
725 const char *branch1)
726 {
727 char *new_path = unique_path(o, ren1->pair->two->path, branch1);
728 output(o, 1, "Renaming %s to %s instead", ren1->pair->one->path, new_path);
729 remove_file(o, 0, ren1->pair->two->path, 0);
730 update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
731 free(new_path);
732 }
734 static void conflict_rename_rename_2(struct merge_options *o,
735 struct rename *ren1,
736 const char *branch1,
737 struct rename *ren2,
738 const char *branch2)
739 {
740 char *new_path1 = unique_path(o, ren1->pair->two->path, branch1);
741 char *new_path2 = unique_path(o, ren2->pair->two->path, branch2);
742 output(o, 1, "Renaming %s to %s and %s to %s instead",
743 ren1->pair->one->path, new_path1,
744 ren2->pair->one->path, new_path2);
745 remove_file(o, 0, ren1->pair->two->path, 0);
746 update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
747 update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
748 free(new_path2);
749 free(new_path1);
750 }
752 static int process_renames(struct merge_options *o,
753 struct string_list *a_renames,
754 struct string_list *b_renames)
755 {
756 int clean_merge = 1, i, j;
757 struct string_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
758 const struct rename *sre;
760 for (i = 0; i < a_renames->nr; i++) {
761 sre = a_renames->items[i].util;
762 string_list_insert(sre->pair->two->path, &a_by_dst)->util
763 = sre->dst_entry;
764 }
765 for (i = 0; i < b_renames->nr; i++) {
766 sre = b_renames->items[i].util;
767 string_list_insert(sre->pair->two->path, &b_by_dst)->util
768 = sre->dst_entry;
769 }
771 for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
772 int compare;
773 char *src;
774 struct string_list *renames1, *renames2, *renames2Dst;
775 struct rename *ren1 = NULL, *ren2 = NULL;
776 const char *branch1, *branch2;
777 const char *ren1_src, *ren1_dst;
779 if (i >= a_renames->nr) {
780 compare = 1;
781 ren2 = b_renames->items[j++].util;
782 } else if (j >= b_renames->nr) {
783 compare = -1;
784 ren1 = a_renames->items[i++].util;
785 } else {
786 compare = strcmp(a_renames->items[i].string,
787 b_renames->items[j].string);
788 if (compare <= 0)
789 ren1 = a_renames->items[i++].util;
790 if (compare >= 0)
791 ren2 = b_renames->items[j++].util;
792 }
794 /* TODO: refactor, so that 1/2 are not needed */
795 if (ren1) {
796 renames1 = a_renames;
797 renames2 = b_renames;
798 renames2Dst = &b_by_dst;
799 branch1 = o->branch1;
800 branch2 = o->branch2;
801 } else {
802 struct rename *tmp;
803 renames1 = b_renames;
804 renames2 = a_renames;
805 renames2Dst = &a_by_dst;
806 branch1 = o->branch2;
807 branch2 = o->branch1;
808 tmp = ren2;
809 ren2 = ren1;
810 ren1 = tmp;
811 }
812 src = ren1->pair->one->path;
814 ren1->dst_entry->processed = 1;
815 ren1->src_entry->processed = 1;
817 if (ren1->processed)
818 continue;
819 ren1->processed = 1;
821 ren1_src = ren1->pair->one->path;
822 ren1_dst = ren1->pair->two->path;
824 if (ren2) {
825 const char *ren2_src = ren2->pair->one->path;
826 const char *ren2_dst = ren2->pair->two->path;
827 /* Renamed in 1 and renamed in 2 */
828 if (strcmp(ren1_src, ren2_src) != 0)
829 die("ren1.src != ren2.src");
830 ren2->dst_entry->processed = 1;
831 ren2->processed = 1;
832 if (strcmp(ren1_dst, ren2_dst) != 0) {
833 clean_merge = 0;
834 output(o, 1, "CONFLICT (rename/rename): "
835 "Rename \"%s\"->\"%s\" in branch \"%s\" "
836 "rename \"%s\"->\"%s\" in \"%s\"%s",
837 src, ren1_dst, branch1,
838 src, ren2_dst, branch2,
839 o->call_depth ? " (left unresolved)": "");
840 if (o->call_depth) {
841 remove_file_from_cache(src);
842 update_file(o, 0, ren1->pair->one->sha1,
843 ren1->pair->one->mode, src);
844 }
845 conflict_rename_rename(o, ren1, branch1, ren2, branch2);
846 } else {
847 struct merge_file_info mfi;
848 remove_file(o, 1, ren1_src, 1);
849 mfi = merge_file(o,
850 ren1->pair->one,
851 ren1->pair->two,
852 ren2->pair->two,
853 branch1,
854 branch2);
855 if (mfi.merge || !mfi.clean)
856 output(o, 1, "Renaming %s->%s", src, ren1_dst);
858 if (mfi.merge)
859 output(o, 2, "Auto-merging %s", ren1_dst);
861 if (!mfi.clean) {
862 output(o, 1, "CONFLICT (content): merge conflict in %s",
863 ren1_dst);
864 clean_merge = 0;
866 if (!o->call_depth)
867 update_stages(ren1_dst,
868 ren1->pair->one,
869 ren1->pair->two,
870 ren2->pair->two,
871 1 /* clear */);
872 }
873 update_file(o, mfi.clean, mfi.sha, mfi.mode, ren1_dst);
874 }
875 } else {
876 /* Renamed in 1, maybe changed in 2 */
877 struct string_list_item *item;
878 /* we only use sha1 and mode of these */
879 struct diff_filespec src_other, dst_other;
880 int try_merge, stage = a_renames == renames1 ? 3: 2;
882 remove_file(o, 1, ren1_src, o->call_depth || stage == 3);
884 hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
885 src_other.mode = ren1->src_entry->stages[stage].mode;
886 hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
887 dst_other.mode = ren1->dst_entry->stages[stage].mode;
889 try_merge = 0;
891 if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
892 clean_merge = 0;
893 output(o, 1, "CONFLICT (rename/directory): Rename %s->%s in %s "
894 " directory %s added in %s",
895 ren1_src, ren1_dst, branch1,
896 ren1_dst, branch2);
897 conflict_rename_dir(o, ren1, branch1);
898 } else if (sha_eq(src_other.sha1, null_sha1)) {
899 clean_merge = 0;
900 output(o, 1, "CONFLICT (rename/delete): Rename %s->%s in %s "
901 "and deleted in %s",
902 ren1_src, ren1_dst, branch1,
903 branch2);
904 update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
905 } else if (!sha_eq(dst_other.sha1, null_sha1)) {
906 const char *new_path;
907 clean_merge = 0;
908 try_merge = 1;
909 output(o, 1, "CONFLICT (rename/add): Rename %s->%s in %s. "
910 "%s added in %s",
911 ren1_src, ren1_dst, branch1,
912 ren1_dst, branch2);
913 new_path = unique_path(o, ren1_dst, branch2);
914 output(o, 1, "Adding as %s instead", new_path);
915 update_file(o, 0, dst_other.sha1, dst_other.mode, new_path);
916 } else if ((item = string_list_lookup(ren1_dst, renames2Dst))) {
917 ren2 = item->util;
918 clean_merge = 0;
919 ren2->processed = 1;
920 output(o, 1, "CONFLICT (rename/rename): "
921 "Rename %s->%s in %s. "
922 "Rename %s->%s in %s",
923 ren1_src, ren1_dst, branch1,
924 ren2->pair->one->path, ren2->pair->two->path, branch2);
925 conflict_rename_rename_2(o, ren1, branch1, ren2, branch2);
926 } else
927 try_merge = 1;
929 if (try_merge) {
930 struct diff_filespec *one, *a, *b;
931 struct merge_file_info mfi;
932 src_other.path = (char *)ren1_src;
934 one = ren1->pair->one;
935 if (a_renames == renames1) {
936 a = ren1->pair->two;
937 b = &src_other;
938 } else {
939 b = ren1->pair->two;
940 a = &src_other;
941 }
942 mfi = merge_file(o, one, a, b,
943 o->branch1, o->branch2);
945 if (mfi.clean &&
946 sha_eq(mfi.sha, ren1->pair->two->sha1) &&
947 mfi.mode == ren1->pair->two->mode)
948 /*
949 * This messaged is part of
950 * t6022 test. If you change
951 * it update the test too.
952 */
953 output(o, 3, "Skipped %s (merged same as existing)", ren1_dst);
954 else {
955 if (mfi.merge || !mfi.clean)
956 output(o, 1, "Renaming %s => %s", ren1_src, ren1_dst);
957 if (mfi.merge)
958 output(o, 2, "Auto-merging %s", ren1_dst);
959 if (!mfi.clean) {
960 output(o, 1, "CONFLICT (rename/modify): Merge conflict in %s",
961 ren1_dst);
962 clean_merge = 0;
964 if (!o->call_depth)
965 update_stages(ren1_dst,
966 one, a, b, 1);
967 }
968 update_file(o, mfi.clean, mfi.sha, mfi.mode, ren1_dst);
969 }
970 }
971 }
972 }
973 string_list_clear(&a_by_dst, 0);
974 string_list_clear(&b_by_dst, 0);
976 return clean_merge;
977 }
979 static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
980 {
981 return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
982 }
984 /* Per entry merge function */
985 static int process_entry(struct merge_options *o,
986 const char *path, struct stage_data *entry)
987 {
988 /*
989 printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
990 print_index_entry("\tpath: ", entry);
991 */
992 int clean_merge = 1;
993 unsigned o_mode = entry->stages[1].mode;
994 unsigned a_mode = entry->stages[2].mode;
995 unsigned b_mode = entry->stages[3].mode;
996 unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
997 unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
998 unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1000 if (o_sha && (!a_sha || !b_sha)) {
1001 /* Case A: Deleted in one */
1002 if ((!a_sha && !b_sha) ||
1003 (sha_eq(a_sha, o_sha) && !b_sha) ||
1004 (!a_sha && sha_eq(b_sha, o_sha))) {
1005 /* Deleted in both or deleted in one and
1006 * unchanged in the other */
1007 if (a_sha)
1008 output(o, 2, "Removing %s", path);
1009 /* do not touch working file if it did not exist */
1010 remove_file(o, 1, path, !a_sha);
1011 } else {
1012 /* Deleted in one and changed in the other */
1013 clean_merge = 0;
1014 if (!a_sha) {
1015 output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1016 "and modified in %s. Version %s of %s left in tree.",
1017 path, o->branch1,
1018 o->branch2, o->branch2, path);
1019 update_file(o, 0, b_sha, b_mode, path);
1020 } else {
1021 output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
1022 "and modified in %s. Version %s of %s left in tree.",
1023 path, o->branch2,
1024 o->branch1, o->branch1, path);
1025 update_file(o, 0, a_sha, a_mode, path);
1026 }
1027 }
1029 } else if ((!o_sha && a_sha && !b_sha) ||
1030 (!o_sha && !a_sha && b_sha)) {
1031 /* Case B: Added in one. */
1032 const char *add_branch;
1033 const char *other_branch;
1034 unsigned mode;
1035 const unsigned char *sha;
1036 const char *conf;
1038 if (a_sha) {
1039 add_branch = o->branch1;
1040 other_branch = o->branch2;
1041 mode = a_mode;
1042 sha = a_sha;
1043 conf = "file/directory";
1044 } else {
1045 add_branch = o->branch2;
1046 other_branch = o->branch1;
1047 mode = b_mode;
1048 sha = b_sha;
1049 conf = "directory/file";
1050 }
1051 if (string_list_has_string(&o->current_directory_set, path)) {
1052 const char *new_path = unique_path(o, path, add_branch);
1053 clean_merge = 0;
1054 output(o, 1, "CONFLICT (%s): There is a directory with name %s in %s. "
1055 "Adding %s as %s",
1056 conf, path, other_branch, path, new_path);
1057 remove_file(o, 0, path, 0);
1058 update_file(o, 0, sha, mode, new_path);
1059 } else {
1060 output(o, 2, "Adding %s", path);
1061 update_file(o, 1, sha, mode, path);
1062 }
1063 } else if (a_sha && b_sha) {
1064 /* Case C: Added in both (check for same permissions) and */
1065 /* case D: Modified in both, but differently. */
1066 const char *reason = "content";
1067 struct merge_file_info mfi;
1068 struct diff_filespec one, a, b;
1070 if (!o_sha) {
1071 reason = "add/add";
1072 o_sha = (unsigned char *)null_sha1;
1073 }
1074 output(o, 2, "Auto-merging %s", path);
1075 one.path = a.path = b.path = (char *)path;
1076 hashcpy(one.sha1, o_sha);
1077 one.mode = o_mode;
1078 hashcpy(a.sha1, a_sha);
1079 a.mode = a_mode;
1080 hashcpy(b.sha1, b_sha);
1081 b.mode = b_mode;
1083 mfi = merge_file(o, &one, &a, &b,
1084 o->branch1, o->branch2);
1086 clean_merge = mfi.clean;
1087 if (mfi.clean)
1088 update_file(o, 1, mfi.sha, mfi.mode, path);
1089 else if (S_ISGITLINK(mfi.mode))
1090 output(o, 1, "CONFLICT (submodule): Merge conflict in %s "
1091 "- needs %s", path, sha1_to_hex(b.sha1));
1092 else {
1093 output(o, 1, "CONFLICT (%s): Merge conflict in %s",
1094 reason, path);
1096 if (o->call_depth)
1097 update_file(o, 0, mfi.sha, mfi.mode, path);
1098 else
1099 update_file_flags(o, mfi.sha, mfi.mode, path,
1100 0 /* update_cache */, 1 /* update_working_directory */);
1101 }
1102 } else if (!o_sha && !a_sha && !b_sha) {
1103 /*
1104 * this entry was deleted altogether. a_mode == 0 means
1105 * we had that path and want to actively remove it.
1106 */
1107 remove_file(o, 1, path, !a_mode);
1108 } else
1109 die("Fatal merge failure, shouldn't happen.");
1111 return clean_merge;
1112 }
1114 int merge_trees(struct merge_options *o,
1115 struct tree *head,
1116 struct tree *merge,
1117 struct tree *common,
1118 struct tree **result)
1119 {
1120 int code, clean;
1122 if (o->subtree_merge) {
1123 merge = shift_tree_object(head, merge);
1124 common = shift_tree_object(head, common);
1125 }
1127 if (sha_eq(common->object.sha1, merge->object.sha1)) {
1128 output(o, 0, "Already uptodate!");
1129 *result = head;
1130 return 1;
1131 }
1133 code = git_merge_trees(o->call_depth, common, head, merge);
1135 if (code != 0)
1136 die("merging of trees %s and %s failed",
1137 sha1_to_hex(head->object.sha1),
1138 sha1_to_hex(merge->object.sha1));
1140 if (unmerged_cache()) {
1141 struct string_list *entries, *re_head, *re_merge;
1142 int i;
1143 string_list_clear(&o->current_file_set, 1);
1144 string_list_clear(&o->current_directory_set, 1);
1145 get_files_dirs(o, head);
1146 get_files_dirs(o, merge);
1148 entries = get_unmerged();
1149 re_head = get_renames(o, head, common, head, merge, entries);
1150 re_merge = get_renames(o, merge, common, head, merge, entries);
1151 clean = process_renames(o, re_head, re_merge);
1152 for (i = 0; i < entries->nr; i++) {
1153 const char *path = entries->items[i].string;
1154 struct stage_data *e = entries->items[i].util;
1155 if (!e->processed
1156 && !process_entry(o, path, e))
1157 clean = 0;
1158 }
1160 string_list_clear(re_merge, 0);
1161 string_list_clear(re_head, 0);
1162 string_list_clear(entries, 1);
1164 }
1165 else
1166 clean = 1;
1168 if (o->call_depth)
1169 *result = write_tree_from_memory(o);
1171 return clean;
1172 }
1174 static struct commit_list *reverse_commit_list(struct commit_list *list)
1175 {
1176 struct commit_list *next = NULL, *current, *backup;
1177 for (current = list; current; current = backup) {
1178 backup = current->next;
1179 current->next = next;
1180 next = current;
1181 }
1182 return next;
1183 }
1185 /*
1186 * Merge the commits h1 and h2, return the resulting virtual
1187 * commit object and a flag indicating the cleanness of the merge.
1188 */
1189 int merge_recursive(struct merge_options *o,
1190 struct commit *h1,
1191 struct commit *h2,
1192 struct commit_list *ca,
1193 struct commit **result)
1194 {
1195 struct commit_list *iter;
1196 struct commit *merged_common_ancestors;
1197 struct tree *mrtree = mrtree;
1198 int clean;
1200 if (show(o, 4)) {
1201 output(o, 4, "Merging:");
1202 output_commit_title(o, h1);
1203 output_commit_title(o, h2);
1204 }
1206 if (!ca) {
1207 ca = get_merge_bases(h1, h2, 1);
1208 ca = reverse_commit_list(ca);
1209 }
1211 if (show(o, 5)) {
1212 output(o, 5, "found %u common ancestor(s):", commit_list_count(ca));
1213 for (iter = ca; iter; iter = iter->next)
1214 output_commit_title(o, iter->item);
1215 }
1217 merged_common_ancestors = pop_commit(&ca);
1218 if (merged_common_ancestors == NULL) {
1219 /* if there is no common ancestor, make an empty tree */
1220 struct tree *tree = xcalloc(1, sizeof(struct tree));
1222 tree->object.parsed = 1;
1223 tree->object.type = OBJ_TREE;
1224 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1225 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1226 }
1228 for (iter = ca; iter; iter = iter->next) {
1229 const char *saved_b1, *saved_b2;
1230 o->call_depth++;
1231 /*
1232 * When the merge fails, the result contains files
1233 * with conflict markers. The cleanness flag is
1234 * ignored, it was never actually used, as result of
1235 * merge_trees has always overwritten it: the committed
1236 * "conflicts" were already resolved.
1237 */
1238 discard_cache();
1239 saved_b1 = o->branch1;
1240 saved_b2 = o->branch2;
1241 o->branch1 = "Temporary merge branch 1";
1242 o->branch2 = "Temporary merge branch 2";
1243 merge_recursive(o, merged_common_ancestors, iter->item,
1244 NULL, &merged_common_ancestors);
1245 o->branch1 = saved_b1;
1246 o->branch2 = saved_b2;
1247 o->call_depth--;
1249 if (!merged_common_ancestors)
1250 die("merge returned no commit");
1251 }
1253 discard_cache();
1254 if (!o->call_depth)
1255 read_cache();
1257 clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
1258 &mrtree);
1260 if (o->call_depth) {
1261 *result = make_virtual_commit(mrtree, "merged tree");
1262 commit_list_insert(h1, &(*result)->parents);
1263 commit_list_insert(h2, &(*result)->parents->next);
1264 }
1265 flush_output(o);
1266 return clean;
1267 }
1269 static struct commit *get_ref(const unsigned char *sha1, const char *name)
1270 {
1271 struct object *object;
1273 object = deref_tag(parse_object(sha1), name, strlen(name));
1274 if (!object)
1275 return NULL;
1276 if (object->type == OBJ_TREE)
1277 return make_virtual_commit((struct tree*)object, name);
1278 if (object->type != OBJ_COMMIT)
1279 return NULL;
1280 if (parse_commit((struct commit *)object))
1281 return NULL;
1282 return (struct commit *)object;
1283 }
1285 int merge_recursive_generic(struct merge_options *o,
1286 const unsigned char *head,
1287 const unsigned char *merge,
1288 int num_base_list,
1289 const unsigned char **base_list,
1290 struct commit **result)
1291 {
1292 int clean, index_fd;
1293 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1294 struct commit *head_commit = get_ref(head, o->branch1);
1295 struct commit *next_commit = get_ref(merge, o->branch2);
1296 struct commit_list *ca = NULL;
1298 if (base_list) {
1299 int i;
1300 for (i = 0; i < num_base_list; ++i) {
1301 struct commit *base;
1302 if (!(base = get_ref(base_list[i], sha1_to_hex(base_list[i]))))
1303 return error("Could not parse object '%s'",
1304 sha1_to_hex(base_list[i]));
1305 commit_list_insert(base, &ca);
1306 }
1307 }
1309 index_fd = hold_locked_index(lock, 1);
1310 clean = merge_recursive(o, head_commit, next_commit, ca,
1311 result);
1312 if (active_cache_changed &&
1313 (write_cache(index_fd, active_cache, active_nr) ||
1314 commit_locked_index(lock)))
1315 return error("Unable to write index.");
1317 return clean ? 0 : 1;
1318 }
1320 static int merge_recursive_config(const char *var, const char *value, void *cb)
1321 {
1322 struct merge_options *o = cb;
1323 if (!strcasecmp(var, "merge.verbosity")) {
1324 o->verbosity = git_config_int(var, value);
1325 return 0;
1326 }
1327 if (!strcasecmp(var, "diff.renamelimit")) {
1328 o->diff_rename_limit = git_config_int(var, value);
1329 return 0;
1330 }
1331 if (!strcasecmp(var, "merge.renamelimit")) {
1332 o->merge_rename_limit = git_config_int(var, value);
1333 return 0;
1334 }
1335 return git_xmerge_config(var, value, cb);
1336 }
1338 void init_merge_options(struct merge_options *o)
1339 {
1340 memset(o, 0, sizeof(struct merge_options));
1341 o->verbosity = 2;
1342 o->buffer_output = 1;
1343 o->diff_rename_limit = -1;
1344 o->merge_rename_limit = -1;
1345 git_config(merge_recursive_config, o);
1346 if (getenv("GIT_MERGE_VERBOSITY"))
1347 o->verbosity =
1348 strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1349 if (o->verbosity >= 5)
1350 o->buffer_output = 0;
1351 strbuf_init(&o->obuf, 0);
1352 memset(&o->current_file_set, 0, sizeof(struct string_list));
1353 o->current_file_set.strdup_strings = 1;
1354 memset(&o->current_directory_set, 0, sizeof(struct string_list));
1355 o->current_directory_set.strdup_strings = 1;
1356 }