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Documentation: convert tutorials to man pages
[git/mjg.git] / builtin-merge-recursive.c
blob46e636fdcf1cb854a486e425df05a2485d18d5d7
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"
22
23 static int subtree_merge;
24
25 static struct tree *shift_tree_object(struct tree *one, struct tree *two)
26 {
27 unsigned char shifted[20];
28
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 }
38
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 */
44
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 }
52
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 }
64
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 }
75
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 };
89
90 static struct path_list current_file_set = {NULL, 0, 0, 1};
91 static struct path_list current_directory_set = {NULL, 0, 0, 1};
92
93 static int call_depth = 0;
94 static int verbosity = 2;
95 static int diff_rename_limit = -1;
96 static int merge_rename_limit = -1;
97 static int buffer_output = 1;
98 static struct strbuf obuf = STRBUF_INIT;
99
100 static int show(int v)
101 {
102 return (!call_depth && verbosity >= v) || verbosity >= 5;
103 }
104
105 static void flush_output(void)
106 {
107 if (obuf.len) {
108 fputs(obuf.buf, stdout);
109 strbuf_reset(&obuf);
110 }
111 }
112
113 static void output(int v, const char *fmt, ...)
114 {
115 int len;
116 va_list ap;
117
118 if (!show(v))
119 return;
120
121 strbuf_grow(&obuf, call_depth * 2 + 2);
122 memset(obuf.buf + obuf.len, ' ', call_depth * 2);
123 strbuf_setlen(&obuf, obuf.len + call_depth * 2);
124
125 va_start(ap, fmt);
126 len = vsnprintf(obuf.buf + obuf.len, strbuf_avail(&obuf), fmt, ap);
127 va_end(ap);
128
129 if (len < 0)
130 len = 0;
131 if (len >= strbuf_avail(&obuf)) {
132 strbuf_grow(&obuf, len + 2);
133 va_start(ap, fmt);
134 len = vsnprintf(obuf.buf + obuf.len, strbuf_avail(&obuf), fmt, ap);
135 va_end(ap);
136 if (len >= strbuf_avail(&obuf)) {
137 die("this should not happen, your snprintf is broken");
138 }
139 }
140 strbuf_setlen(&obuf, obuf.len + len);
141 strbuf_add(&obuf, "\n", 1);
142 if (!buffer_output)
143 flush_output();
144 }
145
146 static void output_commit_title(struct commit *commit)
147 {
148 int i;
149 flush_output();
150 for (i = call_depth; i--;)
151 fputs(" ", stdout);
152 if (commit->util)
153 printf("virtual %s\n", (char *)commit->util);
154 else {
155 printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
156 if (parse_commit(commit) != 0)
157 printf("(bad commit)\n");
158 else {
159 const char *s;
160 int len;
161 for (s = commit->buffer; *s; s++)
162 if (*s == '\n' && s[1] == '\n') {
163 s += 2;
164 break;
165 }
166 for (len = 0; s[len] && '\n' != s[len]; len++)
167 ; /* do nothing */
168 printf("%.*s\n", len, s);
169 }
170 }
171 }
172
173 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
174 const char *path, int stage, int refresh, int options)
175 {
176 struct cache_entry *ce;
177 ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
178 if (!ce)
179 return error("addinfo_cache failed for path '%s'", path);
180 return add_cache_entry(ce, options);
181 }
182
183 /*
184 * This is a global variable which is used in a number of places but
185 * only written to in the 'merge' function.
186 *
187 * index_only == 1 => Don't leave any non-stage 0 entries in the cache and
188 * don't update the working directory.
189 * 0 => Leave unmerged entries in the cache and update
190 * the working directory.
191 */
192 static int index_only = 0;
193
194 static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
195 {
196 parse_tree(tree);
197 init_tree_desc(desc, tree->buffer, tree->size);
198 }
199
200 static int git_merge_trees(int index_only,
201 struct tree *common,
202 struct tree *head,
203 struct tree *merge)
204 {
205 int rc;
206 struct tree_desc t[3];
207 struct unpack_trees_options opts;
208
209 memset(&opts, 0, sizeof(opts));
210 if (index_only)
211 opts.index_only = 1;
212 else
213 opts.update = 1;
214 opts.merge = 1;
215 opts.head_idx = 2;
216 opts.fn = threeway_merge;
217 opts.src_index = &the_index;
218 opts.dst_index = &the_index;
219
220 init_tree_desc_from_tree(t+0, common);
221 init_tree_desc_from_tree(t+1, head);
222 init_tree_desc_from_tree(t+2, merge);
223
224 rc = unpack_trees(3, t, &opts);
225 cache_tree_free(&active_cache_tree);
226 return rc;
227 }
228
229 struct tree *write_tree_from_memory(void)
230 {
231 struct tree *result = NULL;
232
233 if (unmerged_cache()) {
234 int i;
235 output(0, "There are unmerged index entries:");
236 for (i = 0; i < active_nr; i++) {
237 struct cache_entry *ce = active_cache[i];
238 if (ce_stage(ce))
239 output(0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
240 }
241 return NULL;
242 }
243
244 if (!active_cache_tree)
245 active_cache_tree = cache_tree();
246
247 if (!cache_tree_fully_valid(active_cache_tree) &&
248 cache_tree_update(active_cache_tree,
249 active_cache, active_nr, 0, 0) < 0)
250 die("error building trees");
251
252 result = lookup_tree(active_cache_tree->sha1);
253
254 return result;
255 }
256
257 static int save_files_dirs(const unsigned char *sha1,
258 const char *base, int baselen, const char *path,
259 unsigned int mode, int stage)
260 {
261 int len = strlen(path);
262 char *newpath = xmalloc(baselen + len + 1);
263 memcpy(newpath, base, baselen);
264 memcpy(newpath + baselen, path, len);
265 newpath[baselen + len] = '\0';
266
267 if (S_ISDIR(mode))
268 path_list_insert(newpath, &current_directory_set);
269 else
270 path_list_insert(newpath, &current_file_set);
271 free(newpath);
272
273 return READ_TREE_RECURSIVE;
274 }
275
276 static int get_files_dirs(struct tree *tree)
277 {
278 int n;
279 if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs) != 0)
280 return 0;
281 n = current_file_set.nr + current_directory_set.nr;
282 return n;
283 }
284
285 /*
286 * Returns an index_entry instance which doesn't have to correspond to
287 * a real cache entry in Git's index.
288 */
289 static struct stage_data *insert_stage_data(const char *path,
290 struct tree *o, struct tree *a, struct tree *b,
291 struct path_list *entries)
292 {
293 struct path_list_item *item;
294 struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
295 get_tree_entry(o->object.sha1, path,
296 e->stages[1].sha, &e->stages[1].mode);
297 get_tree_entry(a->object.sha1, path,
298 e->stages[2].sha, &e->stages[2].mode);
299 get_tree_entry(b->object.sha1, path,
300 e->stages[3].sha, &e->stages[3].mode);
301 item = path_list_insert(path, entries);
302 item->util = e;
303 return e;
304 }
305
306 /*
307 * Create a dictionary mapping file names to stage_data objects. The
308 * dictionary contains one entry for every path with a non-zero stage entry.
309 */
310 static struct path_list *get_unmerged(void)
311 {
312 struct path_list *unmerged = xcalloc(1, sizeof(struct path_list));
313 int i;
314
315 unmerged->strdup_paths = 1;
316
317 for (i = 0; i < active_nr; i++) {
318 struct path_list_item *item;
319 struct stage_data *e;
320 struct cache_entry *ce = active_cache[i];
321 if (!ce_stage(ce))
322 continue;
323
324 item = path_list_lookup(ce->name, unmerged);
325 if (!item) {
326 item = path_list_insert(ce->name, unmerged);
327 item->util = xcalloc(1, sizeof(struct stage_data));
328 }
329 e = item->util;
330 e->stages[ce_stage(ce)].mode = ce->ce_mode;
331 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
332 }
333
334 return unmerged;
335 }
336
337 struct rename
338 {
339 struct diff_filepair *pair;
340 struct stage_data *src_entry;
341 struct stage_data *dst_entry;
342 unsigned processed:1;
343 };
344
345 /*
346 * Get information of all renames which occurred between 'o_tree' and
347 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
348 * 'b_tree') to be able to associate the correct cache entries with
349 * the rename information. 'tree' is always equal to either a_tree or b_tree.
350 */
351 static struct path_list *get_renames(struct tree *tree,
352 struct tree *o_tree,
353 struct tree *a_tree,
354 struct tree *b_tree,
355 struct path_list *entries)
356 {
357 int i;
358 struct path_list *renames;
359 struct diff_options opts;
360
361 renames = xcalloc(1, sizeof(struct path_list));
362 diff_setup(&opts);
363 DIFF_OPT_SET(&opts, RECURSIVE);
364 opts.detect_rename = DIFF_DETECT_RENAME;
365 opts.rename_limit = merge_rename_limit >= 0 ? merge_rename_limit :
366 diff_rename_limit >= 0 ? diff_rename_limit :
367 500;
368 opts.warn_on_too_large_rename = 1;
369 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
370 if (diff_setup_done(&opts) < 0)
371 die("diff setup failed");
372 diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
373 diffcore_std(&opts);
374 for (i = 0; i < diff_queued_diff.nr; ++i) {
375 struct path_list_item *item;
376 struct rename *re;
377 struct diff_filepair *pair = diff_queued_diff.queue[i];
378 if (pair->status != 'R') {
379 diff_free_filepair(pair);
380 continue;
381 }
382 re = xmalloc(sizeof(*re));
383 re->processed = 0;
384 re->pair = pair;
385 item = path_list_lookup(re->pair->one->path, entries);
386 if (!item)
387 re->src_entry = insert_stage_data(re->pair->one->path,
388 o_tree, a_tree, b_tree, entries);
389 else
390 re->src_entry = item->util;
391
392 item = path_list_lookup(re->pair->two->path, entries);
393 if (!item)
394 re->dst_entry = insert_stage_data(re->pair->two->path,
395 o_tree, a_tree, b_tree, entries);
396 else
397 re->dst_entry = item->util;
398 item = path_list_insert(pair->one->path, renames);
399 item->util = re;
400 }
401 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
402 diff_queued_diff.nr = 0;
403 diff_flush(&opts);
404 return renames;
405 }
406
407 static int update_stages(const char *path, struct diff_filespec *o,
408 struct diff_filespec *a, struct diff_filespec *b,
409 int clear)
410 {
411 int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
412 if (clear)
413 if (remove_file_from_cache(path))
414 return -1;
415 if (o)
416 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
417 return -1;
418 if (a)
419 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
420 return -1;
421 if (b)
422 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
423 return -1;
424 return 0;
425 }
426
427 static int remove_path(const char *name)
428 {
429 int ret;
430 char *slash, *dirs;
431
432 ret = unlink(name);
433 if (ret)
434 return ret;
435 dirs = xstrdup(name);
436 while ((slash = strrchr(name, '/'))) {
437 *slash = '\0';
438 if (rmdir(name) != 0)
439 break;
440 }
441 free(dirs);
442 return ret;
443 }
444
445 static int remove_file(int clean, const char *path, int no_wd)
446 {
447 int update_cache = index_only || clean;
448 int update_working_directory = !index_only && !no_wd;
449
450 if (update_cache) {
451 if (remove_file_from_cache(path))
452 return -1;
453 }
454 if (update_working_directory) {
455 unlink(path);
456 if (errno != ENOENT || errno != EISDIR)
457 return -1;
458 remove_path(path);
459 }
460 return 0;
461 }
462
463 static char *unique_path(const char *path, const char *branch)
464 {
465 char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
466 int suffix = 0;
467 struct stat st;
468 char *p = newpath + strlen(path);
469 strcpy(newpath, path);
470 *(p++) = '~';
471 strcpy(p, branch);
472 for (; *p; ++p)
473 if ('/' == *p)
474 *p = '_';
475 while (path_list_has_path(&current_file_set, newpath) ||
476 path_list_has_path(&current_directory_set, newpath) ||
477 lstat(newpath, &st) == 0)
478 sprintf(p, "_%d", suffix++);
479
480 path_list_insert(newpath, &current_file_set);
481 return newpath;
482 }
483
484 static int mkdir_p(const char *path, unsigned long mode)
485 {
486 /* path points to cache entries, so xstrdup before messing with it */
487 char *buf = xstrdup(path);
488 int result = safe_create_leading_directories(buf);
489 free(buf);
490 return result;
491 }
492
493 static void flush_buffer(int fd, const char *buf, unsigned long size)
494 {
495 while (size > 0) {
496 long ret = write_in_full(fd, buf, size);
497 if (ret < 0) {
498 /* Ignore epipe */
499 if (errno == EPIPE)
500 break;
501 die("merge-recursive: %s", strerror(errno));
502 } else if (!ret) {
503 die("merge-recursive: disk full?");
504 }
505 size -= ret;
506 buf += ret;
507 }
508 }
509
510 static int make_room_for_path(const char *path)
511 {
512 int status;
513 const char *msg = "failed to create path '%s'%s";
514
515 status = mkdir_p(path, 0777);
516 if (status) {
517 if (status == -3) {
518 /* something else exists */
519 error(msg, path, ": perhaps a D/F conflict?");
520 return -1;
521 }
522 die(msg, path, "");
523 }
524
525 /* Successful unlink is good.. */
526 if (!unlink(path))
527 return 0;
528 /* .. and so is no existing file */
529 if (errno == ENOENT)
530 return 0;
531 /* .. but not some other error (who really cares what?) */
532 return error(msg, path, ": perhaps a D/F conflict?");
533 }
534
535 static void update_file_flags(const unsigned char *sha,
536 unsigned mode,
537 const char *path,
538 int update_cache,
539 int update_wd)
540 {
541 if (index_only)
542 update_wd = 0;
543
544 if (update_wd) {
545 enum object_type type;
546 void *buf;
547 unsigned long size;
548
549 if (S_ISGITLINK(mode))
550 die("cannot read object %s '%s': It is a submodule!",
551 sha1_to_hex(sha), path);
552
553 buf = read_sha1_file(sha, &type, &size);
554 if (!buf)
555 die("cannot read object %s '%s'", sha1_to_hex(sha), path);
556 if (type != OBJ_BLOB)
557 die("blob expected for %s '%s'", sha1_to_hex(sha), path);
558
559 if (make_room_for_path(path) < 0) {
560 update_wd = 0;
561 goto update_index;
562 }
563 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
564 int fd;
565 if (mode & 0100)
566 mode = 0777;
567 else
568 mode = 0666;
569 fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
570 if (fd < 0)
571 die("failed to open %s: %s", path, strerror(errno));
572 flush_buffer(fd, buf, size);
573 close(fd);
574 } else if (S_ISLNK(mode)) {
575 char *lnk = xmemdupz(buf, size);
576 mkdir_p(path, 0777);
577 unlink(path);
578 symlink(lnk, path);
579 free(lnk);
580 } else
581 die("do not know what to do with %06o %s '%s'",
582 mode, sha1_to_hex(sha), path);
583 }
584 update_index:
585 if (update_cache)
586 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
587 }
588
589 static void update_file(int clean,
590 const unsigned char *sha,
591 unsigned mode,
592 const char *path)
593 {
594 update_file_flags(sha, mode, path, index_only || clean, !index_only);
595 }
596
597 /* Low level file merging, update and removal */
598
599 struct merge_file_info
600 {
601 unsigned char sha[20];
602 unsigned mode;
603 unsigned clean:1,
604 merge:1;
605 };
606
607 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
608 {
609 unsigned long size;
610 enum object_type type;
611
612 if (!hashcmp(sha1, null_sha1)) {
613 mm->ptr = xstrdup("");
614 mm->size = 0;
615 return;
616 }
617
618 mm->ptr = read_sha1_file(sha1, &type, &size);
619 if (!mm->ptr || type != OBJ_BLOB)
620 die("unable to read blob object %s", sha1_to_hex(sha1));
621 mm->size = size;
622 }
623
624 static int merge_3way(mmbuffer_t *result_buf,
625 struct diff_filespec *o,
626 struct diff_filespec *a,
627 struct diff_filespec *b,
628 const char *branch1,
629 const char *branch2)
630 {
631 mmfile_t orig, src1, src2;
632 char *name1, *name2;
633 int merge_status;
634
635 name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
636 name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
637
638 fill_mm(o->sha1, &orig);
639 fill_mm(a->sha1, &src1);
640 fill_mm(b->sha1, &src2);
641
642 merge_status = ll_merge(result_buf, a->path, &orig,
643 &src1, name1, &src2, name2,
644 index_only);
645
646 free(name1);
647 free(name2);
648 free(orig.ptr);
649 free(src1.ptr);
650 free(src2.ptr);
651 return merge_status;
652 }
653
654 static struct merge_file_info merge_file(struct diff_filespec *o,
655 struct diff_filespec *a, struct diff_filespec *b,
656 const char *branch1, const char *branch2)
657 {
658 struct merge_file_info result;
659 result.merge = 0;
660 result.clean = 1;
661
662 if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
663 result.clean = 0;
664 if (S_ISREG(a->mode)) {
665 result.mode = a->mode;
666 hashcpy(result.sha, a->sha1);
667 } else {
668 result.mode = b->mode;
669 hashcpy(result.sha, b->sha1);
670 }
671 } else {
672 if (!sha_eq(a->sha1, o->sha1) && !sha_eq(b->sha1, o->sha1))
673 result.merge = 1;
674
675 /*
676 * Merge modes
677 */
678 if (a->mode == b->mode || a->mode == o->mode)
679 result.mode = b->mode;
680 else {
681 result.mode = a->mode;
682 if (b->mode != o->mode) {
683 result.clean = 0;
684 result.merge = 1;
685 }
686 }
687
688 if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, o->sha1))
689 hashcpy(result.sha, b->sha1);
690 else if (sha_eq(b->sha1, o->sha1))
691 hashcpy(result.sha, a->sha1);
692 else if (S_ISREG(a->mode)) {
693 mmbuffer_t result_buf;
694 int merge_status;
695
696 merge_status = merge_3way(&result_buf, o, a, b,
697 branch1, branch2);
698
699 if ((merge_status < 0) || !result_buf.ptr)
700 die("Failed to execute internal merge");
701
702 if (write_sha1_file(result_buf.ptr, result_buf.size,
703 blob_type, result.sha))
704 die("Unable to add %s to database",
705 a->path);
706
707 free(result_buf.ptr);
708 result.clean = (merge_status == 0);
709 } else if (S_ISGITLINK(a->mode)) {
710 result.clean = 0;
711 hashcpy(result.sha, a->sha1);
712 } else if (S_ISLNK(a->mode)) {
713 hashcpy(result.sha, a->sha1);
714
715 if (!sha_eq(a->sha1, b->sha1))
716 result.clean = 0;
717 } else {
718 die("unsupported object type in the tree");
719 }
720 }
721
722 return result;
723 }
724
725 static void conflict_rename_rename(struct rename *ren1,
726 const char *branch1,
727 struct rename *ren2,
728 const char *branch2)
729 {
730 char *del[2];
731 int delp = 0;
732 const char *ren1_dst = ren1->pair->two->path;
733 const char *ren2_dst = ren2->pair->two->path;
734 const char *dst_name1 = ren1_dst;
735 const char *dst_name2 = ren2_dst;
736 if (path_list_has_path(&current_directory_set, ren1_dst)) {
737 dst_name1 = del[delp++] = unique_path(ren1_dst, branch1);
738 output(1, "%s is a directory in %s added as %s instead",
739 ren1_dst, branch2, dst_name1);
740 remove_file(0, ren1_dst, 0);
741 }
742 if (path_list_has_path(&current_directory_set, ren2_dst)) {
743 dst_name2 = del[delp++] = unique_path(ren2_dst, branch2);
744 output(1, "%s is a directory in %s added as %s instead",
745 ren2_dst, branch1, dst_name2);
746 remove_file(0, ren2_dst, 0);
747 }
748 if (index_only) {
749 remove_file_from_cache(dst_name1);
750 remove_file_from_cache(dst_name2);
751 /*
752 * Uncomment to leave the conflicting names in the resulting tree
753 *
754 * update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
755 * update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
756 */
757 } else {
758 update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
759 update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
760 }
761 while (delp--)
762 free(del[delp]);
763 }
764
765 static void conflict_rename_dir(struct rename *ren1,
766 const char *branch1)
767 {
768 char *new_path = unique_path(ren1->pair->two->path, branch1);
769 output(1, "Renamed %s to %s instead", ren1->pair->one->path, new_path);
770 remove_file(0, ren1->pair->two->path, 0);
771 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
772 free(new_path);
773 }
774
775 static void conflict_rename_rename_2(struct rename *ren1,
776 const char *branch1,
777 struct rename *ren2,
778 const char *branch2)
779 {
780 char *new_path1 = unique_path(ren1->pair->two->path, branch1);
781 char *new_path2 = unique_path(ren2->pair->two->path, branch2);
782 output(1, "Renamed %s to %s and %s to %s instead",
783 ren1->pair->one->path, new_path1,
784 ren2->pair->one->path, new_path2);
785 remove_file(0, ren1->pair->two->path, 0);
786 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
787 update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
788 free(new_path2);
789 free(new_path1);
790 }
791
792 static int process_renames(struct path_list *a_renames,
793 struct path_list *b_renames,
794 const char *a_branch,
795 const char *b_branch)
796 {
797 int clean_merge = 1, i, j;
798 struct path_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
799 const struct rename *sre;
800
801 for (i = 0; i < a_renames->nr; i++) {
802 sre = a_renames->items[i].util;
803 path_list_insert(sre->pair->two->path, &a_by_dst)->util
804 = sre->dst_entry;
805 }
806 for (i = 0; i < b_renames->nr; i++) {
807 sre = b_renames->items[i].util;
808 path_list_insert(sre->pair->two->path, &b_by_dst)->util
809 = sre->dst_entry;
810 }
811
812 for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
813 int compare;
814 char *src;
815 struct path_list *renames1, *renames2, *renames2Dst;
816 struct rename *ren1 = NULL, *ren2 = NULL;
817 const char *branch1, *branch2;
818 const char *ren1_src, *ren1_dst;
819
820 if (i >= a_renames->nr) {
821 compare = 1;
822 ren2 = b_renames->items[j++].util;
823 } else if (j >= b_renames->nr) {
824 compare = -1;
825 ren1 = a_renames->items[i++].util;
826 } else {
827 compare = strcmp(a_renames->items[i].path,
828 b_renames->items[j].path);
829 if (compare <= 0)
830 ren1 = a_renames->items[i++].util;
831 if (compare >= 0)
832 ren2 = b_renames->items[j++].util;
833 }
834
835 /* TODO: refactor, so that 1/2 are not needed */
836 if (ren1) {
837 renames1 = a_renames;
838 renames2 = b_renames;
839 renames2Dst = &b_by_dst;
840 branch1 = a_branch;
841 branch2 = b_branch;
842 } else {
843 struct rename *tmp;
844 renames1 = b_renames;
845 renames2 = a_renames;
846 renames2Dst = &a_by_dst;
847 branch1 = b_branch;
848 branch2 = a_branch;
849 tmp = ren2;
850 ren2 = ren1;
851 ren1 = tmp;
852 }
853 src = ren1->pair->one->path;
854
855 ren1->dst_entry->processed = 1;
856 ren1->src_entry->processed = 1;
857
858 if (ren1->processed)
859 continue;
860 ren1->processed = 1;
861
862 ren1_src = ren1->pair->one->path;
863 ren1_dst = ren1->pair->two->path;
864
865 if (ren2) {
866 const char *ren2_src = ren2->pair->one->path;
867 const char *ren2_dst = ren2->pair->two->path;
868 /* Renamed in 1 and renamed in 2 */
869 if (strcmp(ren1_src, ren2_src) != 0)
870 die("ren1.src != ren2.src");
871 ren2->dst_entry->processed = 1;
872 ren2->processed = 1;
873 if (strcmp(ren1_dst, ren2_dst) != 0) {
874 clean_merge = 0;
875 output(1, "CONFLICT (rename/rename): "
876 "Rename \"%s\"->\"%s\" in branch \"%s\" "
877 "rename \"%s\"->\"%s\" in \"%s\"%s",
878 src, ren1_dst, branch1,
879 src, ren2_dst, branch2,
880 index_only ? " (left unresolved)": "");
881 if (index_only) {
882 remove_file_from_cache(src);
883 update_file(0, ren1->pair->one->sha1,
884 ren1->pair->one->mode, src);
885 }
886 conflict_rename_rename(ren1, branch1, ren2, branch2);
887 } else {
888 struct merge_file_info mfi;
889 remove_file(1, ren1_src, 1);
890 mfi = merge_file(ren1->pair->one,
891 ren1->pair->two,
892 ren2->pair->two,
893 branch1,
894 branch2);
895 if (mfi.merge || !mfi.clean)
896 output(1, "Renamed %s->%s", src, ren1_dst);
897
898 if (mfi.merge)
899 output(2, "Auto-merged %s", ren1_dst);
900
901 if (!mfi.clean) {
902 output(1, "CONFLICT (content): merge conflict in %s",
903 ren1_dst);
904 clean_merge = 0;
905
906 if (!index_only)
907 update_stages(ren1_dst,
908 ren1->pair->one,
909 ren1->pair->two,
910 ren2->pair->two,
911 1 /* clear */);
912 }
913 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
914 }
915 } else {
916 /* Renamed in 1, maybe changed in 2 */
917 struct path_list_item *item;
918 /* we only use sha1 and mode of these */
919 struct diff_filespec src_other, dst_other;
920 int try_merge, stage = a_renames == renames1 ? 3: 2;
921
922 remove_file(1, ren1_src, index_only || stage == 3);
923
924 hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
925 src_other.mode = ren1->src_entry->stages[stage].mode;
926 hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
927 dst_other.mode = ren1->dst_entry->stages[stage].mode;
928
929 try_merge = 0;
930
931 if (path_list_has_path(&current_directory_set, ren1_dst)) {
932 clean_merge = 0;
933 output(1, "CONFLICT (rename/directory): Renamed %s->%s in %s "
934 " directory %s added in %s",
935 ren1_src, ren1_dst, branch1,
936 ren1_dst, branch2);
937 conflict_rename_dir(ren1, branch1);
938 } else if (sha_eq(src_other.sha1, null_sha1)) {
939 clean_merge = 0;
940 output(1, "CONFLICT (rename/delete): Renamed %s->%s in %s "
941 "and deleted in %s",
942 ren1_src, ren1_dst, branch1,
943 branch2);
944 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
945 } else if (!sha_eq(dst_other.sha1, null_sha1)) {
946 const char *new_path;
947 clean_merge = 0;
948 try_merge = 1;
949 output(1, "CONFLICT (rename/add): Renamed %s->%s in %s. "
950 "%s added in %s",
951 ren1_src, ren1_dst, branch1,
952 ren1_dst, branch2);
953 new_path = unique_path(ren1_dst, branch2);
954 output(1, "Added as %s instead", new_path);
955 update_file(0, dst_other.sha1, dst_other.mode, new_path);
956 } else if ((item = path_list_lookup(ren1_dst, renames2Dst))) {
957 ren2 = item->util;
958 clean_merge = 0;
959 ren2->processed = 1;
960 output(1, "CONFLICT (rename/rename): Renamed %s->%s in %s. "
961 "Renamed %s->%s in %s",
962 ren1_src, ren1_dst, branch1,
963 ren2->pair->one->path, ren2->pair->two->path, branch2);
964 conflict_rename_rename_2(ren1, branch1, ren2, branch2);
965 } else
966 try_merge = 1;
967
968 if (try_merge) {
969 struct diff_filespec *o, *a, *b;
970 struct merge_file_info mfi;
971 src_other.path = (char *)ren1_src;
972
973 o = ren1->pair->one;
974 if (a_renames == renames1) {
975 a = ren1->pair->two;
976 b = &src_other;
977 } else {
978 b = ren1->pair->two;
979 a = &src_other;
980 }
981 mfi = merge_file(o, a, b,
982 a_branch, b_branch);
983
984 if (mfi.clean &&
985 sha_eq(mfi.sha, ren1->pair->two->sha1) &&
986 mfi.mode == ren1->pair->two->mode)
987 /*
988 * This messaged is part of
989 * t6022 test. If you change
990 * it update the test too.
991 */
992 output(3, "Skipped %s (merged same as existing)", ren1_dst);
993 else {
994 if (mfi.merge || !mfi.clean)
995 output(1, "Renamed %s => %s", ren1_src, ren1_dst);
996 if (mfi.merge)
997 output(2, "Auto-merged %s", ren1_dst);
998 if (!mfi.clean) {
999 output(1, "CONFLICT (rename/modify): Merge conflict in %s",
1000 ren1_dst);
1001 clean_merge = 0;
1002
1003 if (!index_only)
1004 update_stages(ren1_dst,
1005 o, a, b, 1);
1006 }
1007 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1008 }
1009 }
1010 }
1011 }
1012 path_list_clear(&a_by_dst, 0);
1013 path_list_clear(&b_by_dst, 0);
1014
1015 return clean_merge;
1016 }
1017
1018 static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1019 {
1020 return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1021 }
1022
1023 /* Per entry merge function */
1024 static int process_entry(const char *path, struct stage_data *entry,
1025 const char *branch1,
1026 const char *branch2)
1027 {
1028 /*
1029 printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1030 print_index_entry("\tpath: ", entry);
1031 */
1032 int clean_merge = 1;
1033 unsigned o_mode = entry->stages[1].mode;
1034 unsigned a_mode = entry->stages[2].mode;
1035 unsigned b_mode = entry->stages[3].mode;
1036 unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1037 unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1038 unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1039
1040 if (o_sha && (!a_sha || !b_sha)) {
1041 /* Case A: Deleted in one */
1042 if ((!a_sha && !b_sha) ||
1043 (sha_eq(a_sha, o_sha) && !b_sha) ||
1044 (!a_sha && sha_eq(b_sha, o_sha))) {
1045 /* Deleted in both or deleted in one and
1046 * unchanged in the other */
1047 if (a_sha)
1048 output(2, "Removed %s", path);
1049 /* do not touch working file if it did not exist */
1050 remove_file(1, path, !a_sha);
1051 } else {
1052 /* Deleted in one and changed in the other */
1053 clean_merge = 0;
1054 if (!a_sha) {
1055 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1056 "and modified in %s. Version %s of %s left in tree.",
1057 path, branch1,
1058 branch2, branch2, path);
1059 update_file(0, b_sha, b_mode, path);
1060 } else {
1061 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1062 "and modified in %s. Version %s of %s left in tree.",
1063 path, branch2,
1064 branch1, branch1, path);
1065 update_file(0, a_sha, a_mode, path);
1066 }
1067 }
1068
1069 } else if ((!o_sha && a_sha && !b_sha) ||
1070 (!o_sha && !a_sha && b_sha)) {
1071 /* Case B: Added in one. */
1072 const char *add_branch;
1073 const char *other_branch;
1074 unsigned mode;
1075 const unsigned char *sha;
1076 const char *conf;
1077
1078 if (a_sha) {
1079 add_branch = branch1;
1080 other_branch = branch2;
1081 mode = a_mode;
1082 sha = a_sha;
1083 conf = "file/directory";
1084 } else {
1085 add_branch = branch2;
1086 other_branch = branch1;
1087 mode = b_mode;
1088 sha = b_sha;
1089 conf = "directory/file";
1090 }
1091 if (path_list_has_path(&current_directory_set, path)) {
1092 const char *new_path = unique_path(path, add_branch);
1093 clean_merge = 0;
1094 output(1, "CONFLICT (%s): There is a directory with name %s in %s. "
1095 "Added %s as %s",
1096 conf, path, other_branch, path, new_path);
1097 remove_file(0, path, 0);
1098 update_file(0, sha, mode, new_path);
1099 } else {
1100 output(2, "Added %s", path);
1101 update_file(1, sha, mode, path);
1102 }
1103 } else if (a_sha && b_sha) {
1104 /* Case C: Added in both (check for same permissions) and */
1105 /* case D: Modified in both, but differently. */
1106 const char *reason = "content";
1107 struct merge_file_info mfi;
1108 struct diff_filespec o, a, b;
1109
1110 if (!o_sha) {
1111 reason = "add/add";
1112 o_sha = (unsigned char *)null_sha1;
1113 }
1114 output(2, "Auto-merged %s", path);
1115 o.path = a.path = b.path = (char *)path;
1116 hashcpy(o.sha1, o_sha);
1117 o.mode = o_mode;
1118 hashcpy(a.sha1, a_sha);
1119 a.mode = a_mode;
1120 hashcpy(b.sha1, b_sha);
1121 b.mode = b_mode;
1122
1123 mfi = merge_file(&o, &a, &b,
1124 branch1, branch2);
1125
1126 clean_merge = mfi.clean;
1127 if (mfi.clean)
1128 update_file(1, mfi.sha, mfi.mode, path);
1129 else if (S_ISGITLINK(mfi.mode))
1130 output(1, "CONFLICT (submodule): Merge conflict in %s "
1131 "- needs %s", path, sha1_to_hex(b.sha1));
1132 else {
1133 output(1, "CONFLICT (%s): Merge conflict in %s",
1134 reason, path);
1135
1136 if (index_only)
1137 update_file(0, mfi.sha, mfi.mode, path);
1138 else
1139 update_file_flags(mfi.sha, mfi.mode, path,
1140 0 /* update_cache */, 1 /* update_working_directory */);
1141 }
1142 } else if (!o_sha && !a_sha && !b_sha) {
1143 /*
1144 * this entry was deleted altogether. a_mode == 0 means
1145 * we had that path and want to actively remove it.
1146 */
1147 remove_file(1, path, !a_mode);
1148 } else
1149 die("Fatal merge failure, shouldn't happen.");
1150
1151 return clean_merge;
1152 }
1153
1154 int merge_trees(struct tree *head,
1155 struct tree *merge,
1156 struct tree *common,
1157 const char *branch1,
1158 const char *branch2,
1159 struct tree **result)
1160 {
1161 int code, clean;
1162
1163 if (subtree_merge) {
1164 merge = shift_tree_object(head, merge);
1165 common = shift_tree_object(head, common);
1166 }
1167
1168 if (sha_eq(common->object.sha1, merge->object.sha1)) {
1169 output(0, "Already uptodate!");
1170 *result = head;
1171 return 1;
1172 }
1173
1174 code = git_merge_trees(index_only, common, head, merge);
1175
1176 if (code != 0)
1177 die("merging of trees %s and %s failed",
1178 sha1_to_hex(head->object.sha1),
1179 sha1_to_hex(merge->object.sha1));
1180
1181 if (unmerged_cache()) {
1182 struct path_list *entries, *re_head, *re_merge;
1183 int i;
1184 path_list_clear(&current_file_set, 1);
1185 path_list_clear(&current_directory_set, 1);
1186 get_files_dirs(head);
1187 get_files_dirs(merge);
1188
1189 entries = get_unmerged();
1190 re_head = get_renames(head, common, head, merge, entries);
1191 re_merge = get_renames(merge, common, head, merge, entries);
1192 clean = process_renames(re_head, re_merge,
1193 branch1, branch2);
1194 for (i = 0; i < entries->nr; i++) {
1195 const char *path = entries->items[i].path;
1196 struct stage_data *e = entries->items[i].util;
1197 if (!e->processed
1198 && !process_entry(path, e, branch1, branch2))
1199 clean = 0;
1200 }
1201
1202 path_list_clear(re_merge, 0);
1203 path_list_clear(re_head, 0);
1204 path_list_clear(entries, 1);
1205
1206 }
1207 else
1208 clean = 1;
1209
1210 if (index_only)
1211 *result = write_tree_from_memory();
1212
1213 return clean;
1214 }
1215
1216 static struct commit_list *reverse_commit_list(struct commit_list *list)
1217 {
1218 struct commit_list *next = NULL, *current, *backup;
1219 for (current = list; current; current = backup) {
1220 backup = current->next;
1221 current->next = next;
1222 next = current;
1223 }
1224 return next;
1225 }
1226
1227 /*
1228 * Merge the commits h1 and h2, return the resulting virtual
1229 * commit object and a flag indicating the cleanness of the merge.
1230 */
1231 int merge_recursive(struct commit *h1,
1232 struct commit *h2,
1233 const char *branch1,
1234 const char *branch2,
1235 struct commit_list *ca,
1236 struct commit **result)
1237 {
1238 struct commit_list *iter;
1239 struct commit *merged_common_ancestors;
1240 struct tree *mrtree = mrtree;
1241 int clean;
1242
1243 if (show(4)) {
1244 output(4, "Merging:");
1245 output_commit_title(h1);
1246 output_commit_title(h2);
1247 }
1248
1249 if (!ca) {
1250 ca = get_merge_bases(h1, h2, 1);
1251 ca = reverse_commit_list(ca);
1252 }
1253
1254 if (show(5)) {
1255 output(5, "found %u common ancestor(s):", commit_list_count(ca));
1256 for (iter = ca; iter; iter = iter->next)
1257 output_commit_title(iter->item);
1258 }
1259
1260 merged_common_ancestors = pop_commit(&ca);
1261 if (merged_common_ancestors == NULL) {
1262 /* if there is no common ancestor, make an empty tree */
1263 struct tree *tree = xcalloc(1, sizeof(struct tree));
1264
1265 tree->object.parsed = 1;
1266 tree->object.type = OBJ_TREE;
1267 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1268 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1269 }
1270
1271 for (iter = ca; iter; iter = iter->next) {
1272 call_depth++;
1273 /*
1274 * When the merge fails, the result contains files
1275 * with conflict markers. The cleanness flag is
1276 * ignored, it was never actually used, as result of
1277 * merge_trees has always overwritten it: the committed
1278 * "conflicts" were already resolved.
1279 */
1280 discard_cache();
1281 merge_recursive(merged_common_ancestors, iter->item,
1282 "Temporary merge branch 1",
1283 "Temporary merge branch 2",
1284 NULL,
1285 &merged_common_ancestors);
1286 call_depth--;
1287
1288 if (!merged_common_ancestors)
1289 die("merge returned no commit");
1290 }
1291
1292 discard_cache();
1293 if (!call_depth) {
1294 read_cache();
1295 index_only = 0;
1296 } else
1297 index_only = 1;
1298
1299 clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
1300 branch1, branch2, &mrtree);
1301
1302 if (index_only) {
1303 *result = make_virtual_commit(mrtree, "merged tree");
1304 commit_list_insert(h1, &(*result)->parents);
1305 commit_list_insert(h2, &(*result)->parents->next);
1306 }
1307 flush_output();
1308 return clean;
1309 }
1310
1311 static const char *better_branch_name(const char *branch)
1312 {
1313 static char githead_env[8 + 40 + 1];
1314 char *name;
1315
1316 if (strlen(branch) != 40)
1317 return branch;
1318 sprintf(githead_env, "GITHEAD_%s", branch);
1319 name = getenv(githead_env);
1320 return name ? name : branch;
1321 }
1322
1323 static struct commit *get_ref(const char *ref)
1324 {
1325 unsigned char sha1[20];
1326 struct object *object;
1327
1328 if (get_sha1(ref, sha1))
1329 die("Could not resolve ref '%s'", ref);
1330 object = deref_tag(parse_object(sha1), ref, strlen(ref));
1331 if (!object)
1332 return NULL;
1333 if (object->type == OBJ_TREE)
1334 return make_virtual_commit((struct tree*)object,
1335 better_branch_name(ref));
1336 if (object->type != OBJ_COMMIT)
1337 return NULL;
1338 if (parse_commit((struct commit *)object))
1339 die("Could not parse commit '%s'", sha1_to_hex(object->sha1));
1340 return (struct commit *)object;
1341 }
1342
1343 static int merge_config(const char *var, const char *value)
1344 {
1345 if (!strcasecmp(var, "merge.verbosity")) {
1346 verbosity = git_config_int(var, value);
1347 return 0;
1348 }
1349 if (!strcasecmp(var, "diff.renamelimit")) {
1350 diff_rename_limit = git_config_int(var, value);
1351 return 0;
1352 }
1353 if (!strcasecmp(var, "merge.renamelimit")) {
1354 merge_rename_limit = git_config_int(var, value);
1355 return 0;
1356 }
1357 return git_default_config(var, value);
1358 }
1359
1360 int cmd_merge_recursive(int argc, const char **argv, const char *prefix)
1361 {
1362 static const char *bases[20];
1363 static unsigned bases_count = 0;
1364 int i, clean;
1365 const char *branch1, *branch2;
1366 struct commit *result, *h1, *h2;
1367 struct commit_list *ca = NULL;
1368 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1369 int index_fd;
1370
1371 if (argv[0]) {
1372 int namelen = strlen(argv[0]);
1373 if (8 < namelen &&
1374 !strcmp(argv[0] + namelen - 8, "-subtree"))
1375 subtree_merge = 1;
1376 }
1377
1378 git_config(merge_config);
1379 if (getenv("GIT_MERGE_VERBOSITY"))
1380 verbosity = strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1381
1382 if (argc < 4)
1383 die("Usage: %s <base>... -- <head> <remote> ...\n", argv[0]);
1384
1385 for (i = 1; i < argc; ++i) {
1386 if (!strcmp(argv[i], "--"))
1387 break;
1388 if (bases_count < sizeof(bases)/sizeof(*bases))
1389 bases[bases_count++] = argv[i];
1390 }
1391 if (argc - i != 3) /* "--" "<head>" "<remote>" */
1392 die("Not handling anything other than two heads merge.");
1393 if (verbosity >= 5)
1394 buffer_output = 0;
1395
1396 branch1 = argv[++i];
1397 branch2 = argv[++i];
1398
1399 h1 = get_ref(branch1);
1400 h2 = get_ref(branch2);
1401
1402 branch1 = better_branch_name(branch1);
1403 branch2 = better_branch_name(branch2);
1404
1405 if (show(3))
1406 printf("Merging %s with %s\n", branch1, branch2);
1407
1408 index_fd = hold_locked_index(lock, 1);
1409
1410 for (i = 0; i < bases_count; i++) {
1411 struct commit *ancestor = get_ref(bases[i]);
1412 ca = commit_list_insert(ancestor, &ca);
1413 }
1414 clean = merge_recursive(h1, h2, branch1, branch2, ca, &result);
1415
1416 if (active_cache_changed &&
1417 (write_cache(index_fd, active_cache, active_nr) ||
1418 commit_locked_index(lock)))
1419 die ("unable to write %s", get_index_file());
1420
1421 return clean ? 0: 1;
1422 }
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