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ec8438b463a5b096ceeca916126e440198ff4740
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 "tree-walk.h"
11 #include "diff.h"
12 #include "diffcore.h"
13 #include "run-command.h"
14 #include "tag.h"
15 #include "unpack-trees.h"
16 #include "path-list.h"
17 #include "xdiff-interface.h"
18 #include "interpolate.h"
19 #include "attr.h"
21 static int subtree_merge;
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
39 * - (const char *)commit->util set to the name, and
40 * - *(int *)commit->object.sha1 set to the virtual id.
41 */
43 static unsigned commit_list_count(const struct commit_list *l)
44 {
45 unsigned c = 0;
46 for (; l; l = l->next )
47 c++;
48 return c;
49 }
51 static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
52 {
53 struct commit *commit = xcalloc(1, sizeof(struct commit));
54 static unsigned virtual_id = 1;
55 commit->tree = tree;
56 commit->util = (void*)comment;
57 *(int*)commit->object.sha1 = virtual_id++;
58 /* avoid warnings */
59 commit->object.parsed = 1;
60 return commit;
61 }
63 /*
64 * Since we use get_tree_entry(), which does not put the read object into
65 * the object pool, we cannot rely on a == b.
66 */
67 static int sha_eq(const unsigned char *a, const unsigned char *b)
68 {
69 if (!a && !b)
70 return 2;
71 return a && b && hashcmp(a, b) == 0;
72 }
74 /*
75 * Since we want to write the index eventually, we cannot reuse the index
76 * for these (temporary) data.
77 */
78 struct stage_data
79 {
80 struct
81 {
82 unsigned mode;
83 unsigned char sha[20];
84 } stages[4];
85 unsigned processed:1;
86 };
88 struct output_buffer
89 {
90 struct output_buffer *next;
91 char *str;
92 };
94 static struct path_list current_file_set = {NULL, 0, 0, 1};
95 static struct path_list current_directory_set = {NULL, 0, 0, 1};
97 static int call_depth = 0;
98 static int verbosity = 2;
99 static int buffer_output = 1;
100 static int do_progress = 1;
101 static unsigned last_percent;
102 static unsigned merged_cnt;
103 static unsigned total_cnt;
104 static volatile sig_atomic_t progress_update;
105 static struct output_buffer *output_list, *output_end;
107 static int show (int v)
108 {
109 return (!call_depth && verbosity >= v) || verbosity >= 5;
110 }
112 static void output(int v, const char *fmt, ...)
113 {
114 va_list args;
115 va_start(args, fmt);
116 if (buffer_output && show(v)) {
117 struct output_buffer *b = xmalloc(sizeof(*b));
118 nfvasprintf(&b->str, fmt, args);
119 b->next = NULL;
120 if (output_end)
121 output_end->next = b;
122 else
123 output_list = b;
124 output_end = b;
125 } else if (show(v)) {
126 int i;
127 for (i = call_depth; i--;)
128 fputs(" ", stdout);
129 vfprintf(stdout, fmt, args);
130 fputc('\n', stdout);
131 }
132 va_end(args);
133 }
135 static void flush_output()
136 {
137 struct output_buffer *b, *n;
138 for (b = output_list; b; b = n) {
139 int i;
140 for (i = call_depth; i--;)
141 fputs(" ", stdout);
142 fputs(b->str, stdout);
143 fputc('\n', stdout);
144 n = b->next;
145 free(b->str);
146 free(b);
147 }
148 output_list = NULL;
149 output_end = NULL;
150 }
152 static void output_commit_title(struct commit *commit)
153 {
154 int i;
155 flush_output();
156 for (i = call_depth; i--;)
157 fputs(" ", stdout);
158 if (commit->util)
159 printf("virtual %s\n", (char *)commit->util);
160 else {
161 printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
162 if (parse_commit(commit) != 0)
163 printf("(bad commit)\n");
164 else {
165 const char *s;
166 int len;
167 for (s = commit->buffer; *s; s++)
168 if (*s == '\n' && s[1] == '\n') {
169 s += 2;
170 break;
171 }
172 for (len = 0; s[len] && '\n' != s[len]; len++)
173 ; /* do nothing */
174 printf("%.*s\n", len, s);
175 }
176 }
177 }
179 static void progress_interval(int signum)
180 {
181 progress_update = 1;
182 }
184 static void setup_progress_signal(void)
185 {
186 struct sigaction sa;
187 struct itimerval v;
189 memset(&sa, 0, sizeof(sa));
190 sa.sa_handler = progress_interval;
191 sigemptyset(&sa.sa_mask);
192 sa.sa_flags = SA_RESTART;
193 sigaction(SIGALRM, &sa, NULL);
195 v.it_interval.tv_sec = 1;
196 v.it_interval.tv_usec = 0;
197 v.it_value = v.it_interval;
198 setitimer(ITIMER_REAL, &v, NULL);
199 }
201 static void display_progress()
202 {
203 unsigned percent = total_cnt ? merged_cnt * 100 / total_cnt : 0;
204 if (progress_update || percent != last_percent) {
205 fprintf(stderr, "%4u%% (%u/%u) done\r",
206 percent, merged_cnt, total_cnt);
207 progress_update = 0;
208 last_percent = percent;
209 }
210 }
212 static struct cache_entry *make_cache_entry(unsigned int mode,
213 const unsigned char *sha1, const char *path, int stage, int refresh)
214 {
215 int size, len;
216 struct cache_entry *ce;
218 if (!verify_path(path))
219 return NULL;
221 len = strlen(path);
222 size = cache_entry_size(len);
223 ce = xcalloc(1, size);
225 hashcpy(ce->sha1, sha1);
226 memcpy(ce->name, path, len);
227 ce->ce_flags = create_ce_flags(len, stage);
228 ce->ce_mode = create_ce_mode(mode);
230 if (refresh)
231 return refresh_cache_entry(ce, 0);
233 return ce;
234 }
236 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
237 const char *path, int stage, int refresh, int options)
238 {
239 struct cache_entry *ce;
240 ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
241 if (!ce)
242 return error("addinfo_cache failed for path '%s'", path);
243 return add_cache_entry(ce, options);
244 }
246 /*
247 * This is a global variable which is used in a number of places but
248 * only written to in the 'merge' function.
249 *
250 * index_only == 1 => Don't leave any non-stage 0 entries in the cache and
251 * don't update the working directory.
252 * 0 => Leave unmerged entries in the cache and update
253 * the working directory.
254 */
255 static int index_only = 0;
257 static int git_merge_trees(int index_only,
258 struct tree *common,
259 struct tree *head,
260 struct tree *merge)
261 {
262 int rc;
263 struct object_list *trees = NULL;
264 struct unpack_trees_options opts;
266 memset(&opts, 0, sizeof(opts));
267 if (index_only)
268 opts.index_only = 1;
269 else
270 opts.update = 1;
271 opts.merge = 1;
272 opts.head_idx = 2;
273 opts.fn = threeway_merge;
275 object_list_append(&common->object, &trees);
276 object_list_append(&head->object, &trees);
277 object_list_append(&merge->object, &trees);
279 rc = unpack_trees(trees, &opts);
280 cache_tree_free(&active_cache_tree);
281 return rc;
282 }
284 static int unmerged_index(void)
285 {
286 int i;
287 for (i = 0; i < active_nr; i++) {
288 struct cache_entry *ce = active_cache[i];
289 if (ce_stage(ce))
290 return 1;
291 }
292 return 0;
293 }
295 static struct tree *git_write_tree(void)
296 {
297 struct tree *result = NULL;
299 if (unmerged_index()) {
300 int i;
301 output(0, "There are unmerged index entries:");
302 for (i = 0; i < active_nr; i++) {
303 struct cache_entry *ce = active_cache[i];
304 if (ce_stage(ce))
305 output(0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
306 }
307 return NULL;
308 }
310 if (!active_cache_tree)
311 active_cache_tree = cache_tree();
313 if (!cache_tree_fully_valid(active_cache_tree) &&
314 cache_tree_update(active_cache_tree,
315 active_cache, active_nr, 0, 0) < 0)
316 die("error building trees");
318 result = lookup_tree(active_cache_tree->sha1);
320 return result;
321 }
323 static int save_files_dirs(const unsigned char *sha1,
324 const char *base, int baselen, const char *path,
325 unsigned int mode, int stage)
326 {
327 int len = strlen(path);
328 char *newpath = xmalloc(baselen + len + 1);
329 memcpy(newpath, base, baselen);
330 memcpy(newpath + baselen, path, len);
331 newpath[baselen + len] = '\0';
333 if (S_ISDIR(mode))
334 path_list_insert(newpath, ¤t_directory_set);
335 else
336 path_list_insert(newpath, ¤t_file_set);
337 free(newpath);
339 return READ_TREE_RECURSIVE;
340 }
342 static int get_files_dirs(struct tree *tree)
343 {
344 int n;
345 if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs) != 0)
346 return 0;
347 n = current_file_set.nr + current_directory_set.nr;
348 return n;
349 }
351 /*
352 * Returns a index_entry instance which doesn't have to correspond to
353 * a real cache entry in Git's index.
354 */
355 static struct stage_data *insert_stage_data(const char *path,
356 struct tree *o, struct tree *a, struct tree *b,
357 struct path_list *entries)
358 {
359 struct path_list_item *item;
360 struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
361 get_tree_entry(o->object.sha1, path,
362 e->stages[1].sha, &e->stages[1].mode);
363 get_tree_entry(a->object.sha1, path,
364 e->stages[2].sha, &e->stages[2].mode);
365 get_tree_entry(b->object.sha1, path,
366 e->stages[3].sha, &e->stages[3].mode);
367 item = path_list_insert(path, entries);
368 item->util = e;
369 return e;
370 }
372 /*
373 * Create a dictionary mapping file names to stage_data objects. The
374 * dictionary contains one entry for every path with a non-zero stage entry.
375 */
376 static struct path_list *get_unmerged(void)
377 {
378 struct path_list *unmerged = xcalloc(1, sizeof(struct path_list));
379 int i;
381 unmerged->strdup_paths = 1;
382 total_cnt += active_nr;
384 for (i = 0; i < active_nr; i++, merged_cnt++) {
385 struct path_list_item *item;
386 struct stage_data *e;
387 struct cache_entry *ce = active_cache[i];
388 if (do_progress)
389 display_progress();
390 if (!ce_stage(ce))
391 continue;
393 item = path_list_lookup(ce->name, unmerged);
394 if (!item) {
395 item = path_list_insert(ce->name, unmerged);
396 item->util = xcalloc(1, sizeof(struct stage_data));
397 }
398 e = item->util;
399 e->stages[ce_stage(ce)].mode = ntohl(ce->ce_mode);
400 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
401 }
403 return unmerged;
404 }
406 struct rename
407 {
408 struct diff_filepair *pair;
409 struct stage_data *src_entry;
410 struct stage_data *dst_entry;
411 unsigned processed:1;
412 };
414 /*
415 * Get information of all renames which occurred between 'o_tree' and
416 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
417 * 'b_tree') to be able to associate the correct cache entries with
418 * the rename information. 'tree' is always equal to either a_tree or b_tree.
419 */
420 static struct path_list *get_renames(struct tree *tree,
421 struct tree *o_tree,
422 struct tree *a_tree,
423 struct tree *b_tree,
424 struct path_list *entries)
425 {
426 int i;
427 struct path_list *renames;
428 struct diff_options opts;
430 renames = xcalloc(1, sizeof(struct path_list));
431 diff_setup(&opts);
432 opts.recursive = 1;
433 opts.detect_rename = DIFF_DETECT_RENAME;
434 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
435 if (diff_setup_done(&opts) < 0)
436 die("diff setup failed");
437 diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
438 diffcore_std(&opts);
439 for (i = 0; i < diff_queued_diff.nr; ++i) {
440 struct path_list_item *item;
441 struct rename *re;
442 struct diff_filepair *pair = diff_queued_diff.queue[i];
443 if (pair->status != 'R') {
444 diff_free_filepair(pair);
445 continue;
446 }
447 re = xmalloc(sizeof(*re));
448 re->processed = 0;
449 re->pair = pair;
450 item = path_list_lookup(re->pair->one->path, entries);
451 if (!item)
452 re->src_entry = insert_stage_data(re->pair->one->path,
453 o_tree, a_tree, b_tree, entries);
454 else
455 re->src_entry = item->util;
457 item = path_list_lookup(re->pair->two->path, entries);
458 if (!item)
459 re->dst_entry = insert_stage_data(re->pair->two->path,
460 o_tree, a_tree, b_tree, entries);
461 else
462 re->dst_entry = item->util;
463 item = path_list_insert(pair->one->path, renames);
464 item->util = re;
465 }
466 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
467 diff_queued_diff.nr = 0;
468 diff_flush(&opts);
469 return renames;
470 }
472 static int update_stages(const char *path, struct diff_filespec *o,
473 struct diff_filespec *a, struct diff_filespec *b,
474 int clear)
475 {
476 int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
477 if (clear)
478 if (remove_file_from_cache(path))
479 return -1;
480 if (o)
481 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
482 return -1;
483 if (a)
484 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
485 return -1;
486 if (b)
487 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
488 return -1;
489 return 0;
490 }
492 static int remove_path(const char *name)
493 {
494 int ret, len;
495 char *slash, *dirs;
497 ret = unlink(name);
498 if (ret)
499 return ret;
500 len = strlen(name);
501 dirs = xmalloc(len+1);
502 memcpy(dirs, name, len);
503 dirs[len] = '\0';
504 while ((slash = strrchr(name, '/'))) {
505 *slash = '\0';
506 len = slash - name;
507 if (rmdir(name) != 0)
508 break;
509 }
510 free(dirs);
511 return ret;
512 }
514 static int remove_file(int clean, const char *path, int no_wd)
515 {
516 int update_cache = index_only || clean;
517 int update_working_directory = !index_only && !no_wd;
519 if (update_cache) {
520 if (remove_file_from_cache(path))
521 return -1;
522 }
523 if (update_working_directory) {
524 unlink(path);
525 if (errno != ENOENT || errno != EISDIR)
526 return -1;
527 remove_path(path);
528 }
529 return 0;
530 }
532 static char *unique_path(const char *path, const char *branch)
533 {
534 char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
535 int suffix = 0;
536 struct stat st;
537 char *p = newpath + strlen(path);
538 strcpy(newpath, path);
539 *(p++) = '~';
540 strcpy(p, branch);
541 for (; *p; ++p)
542 if ('/' == *p)
543 *p = '_';
544 while (path_list_has_path(¤t_file_set, newpath) ||
545 path_list_has_path(¤t_directory_set, newpath) ||
546 lstat(newpath, &st) == 0)
547 sprintf(p, "_%d", suffix++);
549 path_list_insert(newpath, ¤t_file_set);
550 return newpath;
551 }
553 static int mkdir_p(const char *path, unsigned long mode)
554 {
555 /* path points to cache entries, so xstrdup before messing with it */
556 char *buf = xstrdup(path);
557 int result = safe_create_leading_directories(buf);
558 free(buf);
559 return result;
560 }
562 static void flush_buffer(int fd, const char *buf, unsigned long size)
563 {
564 while (size > 0) {
565 long ret = write_in_full(fd, buf, size);
566 if (ret < 0) {
567 /* Ignore epipe */
568 if (errno == EPIPE)
569 break;
570 die("merge-recursive: %s", strerror(errno));
571 } else if (!ret) {
572 die("merge-recursive: disk full?");
573 }
574 size -= ret;
575 buf += ret;
576 }
577 }
579 static void update_file_flags(const unsigned char *sha,
580 unsigned mode,
581 const char *path,
582 int update_cache,
583 int update_wd)
584 {
585 if (index_only)
586 update_wd = 0;
588 if (update_wd) {
589 enum object_type type;
590 void *buf;
591 unsigned long size;
593 buf = read_sha1_file(sha, &type, &size);
594 if (!buf)
595 die("cannot read object %s '%s'", sha1_to_hex(sha), path);
596 if (type != OBJ_BLOB)
597 die("blob expected for %s '%s'", sha1_to_hex(sha), path);
599 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
600 int fd;
601 if (mkdir_p(path, 0777))
602 die("failed to create path %s: %s", path, strerror(errno));
603 unlink(path);
604 if (mode & 0100)
605 mode = 0777;
606 else
607 mode = 0666;
608 fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
609 if (fd < 0)
610 die("failed to open %s: %s", path, strerror(errno));
611 flush_buffer(fd, buf, size);
612 close(fd);
613 } else if (S_ISLNK(mode)) {
614 char *lnk = xmalloc(size + 1);
615 memcpy(lnk, buf, size);
616 lnk[size] = '\0';
617 mkdir_p(path, 0777);
618 unlink(path);
619 symlink(lnk, path);
620 free(lnk);
621 } else
622 die("do not know what to do with %06o %s '%s'",
623 mode, sha1_to_hex(sha), path);
624 }
625 if (update_cache)
626 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
627 }
629 static void update_file(int clean,
630 const unsigned char *sha,
631 unsigned mode,
632 const char *path)
633 {
634 update_file_flags(sha, mode, path, index_only || clean, !index_only);
635 }
637 /* Low level file merging, update and removal */
639 struct merge_file_info
640 {
641 unsigned char sha[20];
642 unsigned mode;
643 unsigned clean:1,
644 merge:1;
645 };
647 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
648 {
649 unsigned long size;
650 enum object_type type;
652 if (!hashcmp(sha1, null_sha1)) {
653 mm->ptr = xstrdup("");
654 mm->size = 0;
655 return;
656 }
658 mm->ptr = read_sha1_file(sha1, &type, &size);
659 if (!mm->ptr || type != OBJ_BLOB)
660 die("unable to read blob object %s", sha1_to_hex(sha1));
661 mm->size = size;
662 }
664 /*
665 * Customizable low-level merge drivers support.
666 */
668 struct ll_merge_driver;
669 typedef int (*ll_merge_fn)(const struct ll_merge_driver *,
670 const char *path,
671 mmfile_t *orig,
672 mmfile_t *src1, const char *name1,
673 mmfile_t *src2, const char *name2,
674 mmbuffer_t *result);
676 struct ll_merge_driver {
677 const char *name;
678 const char *description;
679 ll_merge_fn fn;
680 const char *recursive;
681 struct ll_merge_driver *next;
682 char *cmdline;
683 };
685 /*
686 * Built-in low-levels
687 */
688 static int ll_xdl_merge(const struct ll_merge_driver *drv_unused,
689 const char *path_unused,
690 mmfile_t *orig,
691 mmfile_t *src1, const char *name1,
692 mmfile_t *src2, const char *name2,
693 mmbuffer_t *result)
694 {
695 xpparam_t xpp;
697 memset(&xpp, 0, sizeof(xpp));
698 return xdl_merge(orig,
699 src1, name1,
700 src2, name2,
701 &xpp, XDL_MERGE_ZEALOUS,
702 result);
703 }
705 static int ll_union_merge(const struct ll_merge_driver *drv_unused,
706 const char *path_unused,
707 mmfile_t *orig,
708 mmfile_t *src1, const char *name1,
709 mmfile_t *src2, const char *name2,
710 mmbuffer_t *result)
711 {
712 char *src, *dst;
713 long size;
714 const int marker_size = 7;
716 int status = ll_xdl_merge(drv_unused, path_unused,
717 orig, src1, NULL, src2, NULL, result);
718 if (status <= 0)
719 return status;
720 size = result->size;
721 src = dst = result->ptr;
722 while (size) {
723 char ch;
724 if ((marker_size < size) &&
725 (*src == '<' || *src == '=' || *src == '>')) {
726 int i;
727 ch = *src;
728 for (i = 0; i < marker_size; i++)
729 if (src[i] != ch)
730 goto not_a_marker;
731 if (src[marker_size] != '\n')
732 goto not_a_marker;
733 src += marker_size + 1;
734 size -= marker_size + 1;
735 continue;
736 }
737 not_a_marker:
738 do {
739 ch = *src++;
740 *dst++ = ch;
741 size--;
742 } while (ch != '\n' && size);
743 }
744 result->size = dst - result->ptr;
745 return 0;
746 }
748 static int ll_binary_merge(const struct ll_merge_driver *drv_unused,
749 const char *path_unused,
750 mmfile_t *orig,
751 mmfile_t *src1, const char *name1,
752 mmfile_t *src2, const char *name2,
753 mmbuffer_t *result)
754 {
755 /*
756 * The tentative merge result is "ours" for the final round,
757 * or common ancestor for an internal merge. Still return
758 * "conflicted merge" status.
759 */
760 mmfile_t *stolen = index_only ? orig : src1;
762 result->ptr = stolen->ptr;
763 result->size = stolen->size;
764 stolen->ptr = NULL;
765 return 1;
766 }
768 #define LL_BINARY_MERGE 0
769 #define LL_TEXT_MERGE 1
770 #define LL_UNION_MERGE 2
771 static struct ll_merge_driver ll_merge_drv[] = {
772 { "binary", "built-in binary merge", ll_binary_merge },
773 { "text", "built-in 3-way text merge", ll_xdl_merge },
774 { "union", "built-in union merge", ll_union_merge },
775 };
777 static void create_temp(mmfile_t *src, char *path)
778 {
779 int fd;
781 strcpy(path, ".merge_file_XXXXXX");
782 fd = mkstemp(path);
783 if (fd < 0)
784 die("unable to create temp-file");
785 if (write_in_full(fd, src->ptr, src->size) != src->size)
786 die("unable to write temp-file");
787 close(fd);
788 }
790 /*
791 * User defined low-level merge driver support.
792 */
793 static int ll_ext_merge(const struct ll_merge_driver *fn,
794 const char *path,
795 mmfile_t *orig,
796 mmfile_t *src1, const char *name1,
797 mmfile_t *src2, const char *name2,
798 mmbuffer_t *result)
799 {
800 char temp[3][50];
801 char cmdbuf[2048];
802 struct interp table[] = {
803 { "%O" },
804 { "%A" },
805 { "%B" },
806 };
807 struct child_process child;
808 const char *args[20];
809 int status, fd, i;
810 struct stat st;
812 result->ptr = NULL;
813 result->size = 0;
814 create_temp(orig, temp[0]);
815 create_temp(src1, temp[1]);
816 create_temp(src2, temp[2]);
818 interp_set_entry(table, 0, temp[0]);
819 interp_set_entry(table, 1, temp[1]);
820 interp_set_entry(table, 2, temp[2]);
822 output(1, "merging %s using %s", path,
823 fn->description ? fn->description : fn->name);
825 interpolate(cmdbuf, sizeof(cmdbuf), fn->cmdline, table, 3);
827 memset(&child, 0, sizeof(child));
828 child.argv = args;
829 args[0] = "sh";
830 args[1] = "-c";
831 args[2] = cmdbuf;
832 args[3] = NULL;
834 status = run_command(&child);
835 if (status < -ERR_RUN_COMMAND_FORK)
836 ; /* failure in run-command */
837 else
838 status = -status;
839 fd = open(temp[1], O_RDONLY);
840 if (fd < 0)
841 goto bad;
842 if (fstat(fd, &st))
843 goto close_bad;
844 result->size = st.st_size;
845 result->ptr = xmalloc(result->size + 1);
846 if (read_in_full(fd, result->ptr, result->size) != result->size) {
847 free(result->ptr);
848 result->ptr = NULL;
849 result->size = 0;
850 }
851 close_bad:
852 close(fd);
853 bad:
854 for (i = 0; i < 3; i++)
855 unlink(temp[i]);
856 return status;
857 }
859 /*
860 * merge.default and merge.driver configuration items
861 */
862 static struct ll_merge_driver *ll_user_merge, **ll_user_merge_tail;
863 static const char *default_ll_merge;
865 static int read_merge_config(const char *var, const char *value)
866 {
867 struct ll_merge_driver *fn;
868 const char *ep, *name;
869 int namelen;
871 if (!strcmp(var, "merge.default")) {
872 if (value)
873 default_ll_merge = strdup(value);
874 return 0;
875 }
877 /*
878 * We are not interested in anything but "merge.<name>.variable";
879 * especially, we do not want to look at variables such as
880 * "merge.summary", "merge.tool", and "merge.verbosity".
881 */
882 if (prefixcmp(var, "merge.") || (ep = strrchr(var, '.')) == var + 6)
883 return 0;
885 /*
886 * Find existing one as we might be processing merge.<name>.var2
887 * after seeing merge.<name>.var1.
888 */
889 name = var + 6;
890 namelen = ep - name;
891 for (fn = ll_user_merge; fn; fn = fn->next)
892 if (!strncmp(fn->name, name, namelen) && !fn->name[namelen])
893 break;
894 if (!fn) {
895 char *namebuf;
896 fn = xcalloc(1, sizeof(struct ll_merge_driver));
897 namebuf = xmalloc(namelen + 1);
898 memcpy(namebuf, name, namelen);
899 namebuf[namelen] = 0;
900 fn->name = namebuf;
901 fn->fn = ll_ext_merge;
902 fn->next = *ll_user_merge_tail;
903 *ll_user_merge_tail = fn;
904 }
906 ep++;
908 if (!strcmp("name", ep)) {
909 if (!value)
910 return error("%s: lacks value", var);
911 fn->description = strdup(value);
912 return 0;
913 }
915 if (!strcmp("driver", ep)) {
916 if (!value)
917 return error("%s: lacks value", var);
918 /*
919 * merge.<name>.driver specifies the command line:
920 *
921 * command-line
922 *
923 * The command-line will be interpolated with the following
924 * tokens and is given to the shell:
925 *
926 * %O - temporary file name for the merge base.
927 * %A - temporary file name for our version.
928 * %B - temporary file name for the other branches' version.
929 *
930 * The external merge driver should write the results in the
931 * file named by %A, and signal that it has done with zero exit
932 * status.
933 */
934 fn->cmdline = strdup(value);
935 return 0;
936 }
938 if (!strcmp("recursive", ep)) {
939 if (!value)
940 return error("%s: lacks value", var);
941 fn->recursive = strdup(value);
942 return 0;
943 }
945 return 0;
946 }
948 static void initialize_ll_merge(void)
949 {
950 if (ll_user_merge_tail)
951 return;
952 ll_user_merge_tail = &ll_user_merge;
953 git_config(read_merge_config);
954 }
956 static const struct ll_merge_driver *find_ll_merge_driver(const char *merge_attr)
957 {
958 struct ll_merge_driver *fn;
959 const char *name;
960 int i;
962 initialize_ll_merge();
964 if (ATTR_TRUE(merge_attr))
965 return &ll_merge_drv[LL_TEXT_MERGE];
966 else if (ATTR_FALSE(merge_attr))
967 return &ll_merge_drv[LL_BINARY_MERGE];
968 else if (ATTR_UNSET(merge_attr)) {
969 if (!default_ll_merge)
970 return &ll_merge_drv[LL_TEXT_MERGE];
971 else
972 name = default_ll_merge;
973 }
974 else
975 name = merge_attr;
977 for (fn = ll_user_merge; fn; fn = fn->next)
978 if (!strcmp(fn->name, name))
979 return fn;
981 for (i = 0; i < ARRAY_SIZE(ll_merge_drv); i++)
982 if (!strcmp(ll_merge_drv[i].name, name))
983 return &ll_merge_drv[i];
985 /* default to the 3-way */
986 return &ll_merge_drv[LL_TEXT_MERGE];
987 }
989 static const char *git_path_check_merge(const char *path)
990 {
991 static struct git_attr_check attr_merge_check;
993 if (!attr_merge_check.attr)
994 attr_merge_check.attr = git_attr("merge", 5);
996 if (git_checkattr(path, 1, &attr_merge_check))
997 return NULL;
998 return attr_merge_check.value;
999 }
1001 static int ll_merge(mmbuffer_t *result_buf,
1002 struct diff_filespec *o,
1003 struct diff_filespec *a,
1004 struct diff_filespec *b,
1005 const char *branch1,
1006 const char *branch2)
1007 {
1008 mmfile_t orig, src1, src2;
1009 char *name1, *name2;
1010 int merge_status;
1011 const char *ll_driver_name;
1012 const struct ll_merge_driver *driver;
1014 name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
1015 name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
1017 fill_mm(o->sha1, &orig);
1018 fill_mm(a->sha1, &src1);
1019 fill_mm(b->sha1, &src2);
1021 ll_driver_name = git_path_check_merge(a->path);
1022 driver = find_ll_merge_driver(ll_driver_name);
1024 if (index_only && driver->recursive) {
1025 void *merge_attr;
1027 ll_driver_name = driver->recursive;
1028 merge_attr = git_attr(ll_driver_name, strlen(ll_driver_name));
1029 driver = find_ll_merge_driver(merge_attr);
1030 }
1031 merge_status = driver->fn(driver, a->path,
1032 &orig, &src1, name1, &src2, name2,
1033 result_buf);
1035 free(name1);
1036 free(name2);
1037 free(orig.ptr);
1038 free(src1.ptr);
1039 free(src2.ptr);
1040 return merge_status;
1041 }
1043 static struct merge_file_info merge_file(struct diff_filespec *o,
1044 struct diff_filespec *a, struct diff_filespec *b,
1045 const char *branch1, const char *branch2)
1046 {
1047 struct merge_file_info result;
1048 result.merge = 0;
1049 result.clean = 1;
1051 if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
1052 result.clean = 0;
1053 if (S_ISREG(a->mode)) {
1054 result.mode = a->mode;
1055 hashcpy(result.sha, a->sha1);
1056 } else {
1057 result.mode = b->mode;
1058 hashcpy(result.sha, b->sha1);
1059 }
1060 } else {
1061 if (!sha_eq(a->sha1, o->sha1) && !sha_eq(b->sha1, o->sha1))
1062 result.merge = 1;
1064 result.mode = a->mode == o->mode ? b->mode: a->mode;
1066 if (sha_eq(a->sha1, o->sha1))
1067 hashcpy(result.sha, b->sha1);
1068 else if (sha_eq(b->sha1, o->sha1))
1069 hashcpy(result.sha, a->sha1);
1070 else if (S_ISREG(a->mode)) {
1071 mmbuffer_t result_buf;
1072 int merge_status;
1074 merge_status = ll_merge(&result_buf, o, a, b,
1075 branch1, branch2);
1077 if ((merge_status < 0) || !result_buf.ptr)
1078 die("Failed to execute internal merge");
1080 if (write_sha1_file(result_buf.ptr, result_buf.size,
1081 blob_type, result.sha))
1082 die("Unable to add %s to database",
1083 a->path);
1085 free(result_buf.ptr);
1086 result.clean = (merge_status == 0);
1087 } else {
1088 if (!(S_ISLNK(a->mode) || S_ISLNK(b->mode)))
1089 die("cannot merge modes?");
1091 hashcpy(result.sha, a->sha1);
1093 if (!sha_eq(a->sha1, b->sha1))
1094 result.clean = 0;
1095 }
1096 }
1098 return result;
1099 }
1101 static void conflict_rename_rename(struct rename *ren1,
1102 const char *branch1,
1103 struct rename *ren2,
1104 const char *branch2)
1105 {
1106 char *del[2];
1107 int delp = 0;
1108 const char *ren1_dst = ren1->pair->two->path;
1109 const char *ren2_dst = ren2->pair->two->path;
1110 const char *dst_name1 = ren1_dst;
1111 const char *dst_name2 = ren2_dst;
1112 if (path_list_has_path(¤t_directory_set, ren1_dst)) {
1113 dst_name1 = del[delp++] = unique_path(ren1_dst, branch1);
1114 output(1, "%s is a directory in %s added as %s instead",
1115 ren1_dst, branch2, dst_name1);
1116 remove_file(0, ren1_dst, 0);
1117 }
1118 if (path_list_has_path(¤t_directory_set, ren2_dst)) {
1119 dst_name2 = del[delp++] = unique_path(ren2_dst, branch2);
1120 output(1, "%s is a directory in %s added as %s instead",
1121 ren2_dst, branch1, dst_name2);
1122 remove_file(0, ren2_dst, 0);
1123 }
1124 if (index_only) {
1125 remove_file_from_cache(dst_name1);
1126 remove_file_from_cache(dst_name2);
1127 /*
1128 * Uncomment to leave the conflicting names in the resulting tree
1129 *
1130 * update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
1131 * update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
1132 */
1133 } else {
1134 update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
1135 update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
1136 }
1137 while (delp--)
1138 free(del[delp]);
1139 }
1141 static void conflict_rename_dir(struct rename *ren1,
1142 const char *branch1)
1143 {
1144 char *new_path = unique_path(ren1->pair->two->path, branch1);
1145 output(1, "Renamed %s to %s instead", ren1->pair->one->path, new_path);
1146 remove_file(0, ren1->pair->two->path, 0);
1147 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
1148 free(new_path);
1149 }
1151 static void conflict_rename_rename_2(struct rename *ren1,
1152 const char *branch1,
1153 struct rename *ren2,
1154 const char *branch2)
1155 {
1156 char *new_path1 = unique_path(ren1->pair->two->path, branch1);
1157 char *new_path2 = unique_path(ren2->pair->two->path, branch2);
1158 output(1, "Renamed %s to %s and %s to %s instead",
1159 ren1->pair->one->path, new_path1,
1160 ren2->pair->one->path, new_path2);
1161 remove_file(0, ren1->pair->two->path, 0);
1162 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
1163 update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
1164 free(new_path2);
1165 free(new_path1);
1166 }
1168 static int process_renames(struct path_list *a_renames,
1169 struct path_list *b_renames,
1170 const char *a_branch,
1171 const char *b_branch)
1172 {
1173 int clean_merge = 1, i, j;
1174 struct path_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
1175 const struct rename *sre;
1177 for (i = 0; i < a_renames->nr; i++) {
1178 sre = a_renames->items[i].util;
1179 path_list_insert(sre->pair->two->path, &a_by_dst)->util
1180 = sre->dst_entry;
1181 }
1182 for (i = 0; i < b_renames->nr; i++) {
1183 sre = b_renames->items[i].util;
1184 path_list_insert(sre->pair->two->path, &b_by_dst)->util
1185 = sre->dst_entry;
1186 }
1188 for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
1189 int compare;
1190 char *src;
1191 struct path_list *renames1, *renames2, *renames2Dst;
1192 struct rename *ren1 = NULL, *ren2 = NULL;
1193 const char *branch1, *branch2;
1194 const char *ren1_src, *ren1_dst;
1196 if (i >= a_renames->nr) {
1197 compare = 1;
1198 ren2 = b_renames->items[j++].util;
1199 } else if (j >= b_renames->nr) {
1200 compare = -1;
1201 ren1 = a_renames->items[i++].util;
1202 } else {
1203 compare = strcmp(a_renames->items[i].path,
1204 b_renames->items[j].path);
1205 if (compare <= 0)
1206 ren1 = a_renames->items[i++].util;
1207 if (compare >= 0)
1208 ren2 = b_renames->items[j++].util;
1209 }
1211 /* TODO: refactor, so that 1/2 are not needed */
1212 if (ren1) {
1213 renames1 = a_renames;
1214 renames2 = b_renames;
1215 renames2Dst = &b_by_dst;
1216 branch1 = a_branch;
1217 branch2 = b_branch;
1218 } else {
1219 struct rename *tmp;
1220 renames1 = b_renames;
1221 renames2 = a_renames;
1222 renames2Dst = &a_by_dst;
1223 branch1 = b_branch;
1224 branch2 = a_branch;
1225 tmp = ren2;
1226 ren2 = ren1;
1227 ren1 = tmp;
1228 }
1229 src = ren1->pair->one->path;
1231 ren1->dst_entry->processed = 1;
1232 ren1->src_entry->processed = 1;
1234 if (ren1->processed)
1235 continue;
1236 ren1->processed = 1;
1238 ren1_src = ren1->pair->one->path;
1239 ren1_dst = ren1->pair->two->path;
1241 if (ren2) {
1242 const char *ren2_src = ren2->pair->one->path;
1243 const char *ren2_dst = ren2->pair->two->path;
1244 /* Renamed in 1 and renamed in 2 */
1245 if (strcmp(ren1_src, ren2_src) != 0)
1246 die("ren1.src != ren2.src");
1247 ren2->dst_entry->processed = 1;
1248 ren2->processed = 1;
1249 if (strcmp(ren1_dst, ren2_dst) != 0) {
1250 clean_merge = 0;
1251 output(1, "CONFLICT (rename/rename): "
1252 "Rename \"%s\"->\"%s\" in branch \"%s\" "
1253 "rename \"%s\"->\"%s\" in \"%s\"%s",
1254 src, ren1_dst, branch1,
1255 src, ren2_dst, branch2,
1256 index_only ? " (left unresolved)": "");
1257 if (index_only) {
1258 remove_file_from_cache(src);
1259 update_file(0, ren1->pair->one->sha1,
1260 ren1->pair->one->mode, src);
1261 }
1262 conflict_rename_rename(ren1, branch1, ren2, branch2);
1263 } else {
1264 struct merge_file_info mfi;
1265 remove_file(1, ren1_src, 1);
1266 mfi = merge_file(ren1->pair->one,
1267 ren1->pair->two,
1268 ren2->pair->two,
1269 branch1,
1270 branch2);
1271 if (mfi.merge || !mfi.clean)
1272 output(1, "Renamed %s->%s", src, ren1_dst);
1274 if (mfi.merge)
1275 output(2, "Auto-merged %s", ren1_dst);
1277 if (!mfi.clean) {
1278 output(1, "CONFLICT (content): merge conflict in %s",
1279 ren1_dst);
1280 clean_merge = 0;
1282 if (!index_only)
1283 update_stages(ren1_dst,
1284 ren1->pair->one,
1285 ren1->pair->two,
1286 ren2->pair->two,
1287 1 /* clear */);
1288 }
1289 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1290 }
1291 } else {
1292 /* Renamed in 1, maybe changed in 2 */
1293 struct path_list_item *item;
1294 /* we only use sha1 and mode of these */
1295 struct diff_filespec src_other, dst_other;
1296 int try_merge, stage = a_renames == renames1 ? 3: 2;
1298 remove_file(1, ren1_src, index_only || stage == 3);
1300 hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
1301 src_other.mode = ren1->src_entry->stages[stage].mode;
1302 hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
1303 dst_other.mode = ren1->dst_entry->stages[stage].mode;
1305 try_merge = 0;
1307 if (path_list_has_path(¤t_directory_set, ren1_dst)) {
1308 clean_merge = 0;
1309 output(1, "CONFLICT (rename/directory): Renamed %s->%s in %s "
1310 " directory %s added in %s",
1311 ren1_src, ren1_dst, branch1,
1312 ren1_dst, branch2);
1313 conflict_rename_dir(ren1, branch1);
1314 } else if (sha_eq(src_other.sha1, null_sha1)) {
1315 clean_merge = 0;
1316 output(1, "CONFLICT (rename/delete): Renamed %s->%s in %s "
1317 "and deleted in %s",
1318 ren1_src, ren1_dst, branch1,
1319 branch2);
1320 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
1321 } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1322 const char *new_path;
1323 clean_merge = 0;
1324 try_merge = 1;
1325 output(1, "CONFLICT (rename/add): Renamed %s->%s in %s. "
1326 "%s added in %s",
1327 ren1_src, ren1_dst, branch1,
1328 ren1_dst, branch2);
1329 new_path = unique_path(ren1_dst, branch2);
1330 output(1, "Added as %s instead", new_path);
1331 update_file(0, dst_other.sha1, dst_other.mode, new_path);
1332 } else if ((item = path_list_lookup(ren1_dst, renames2Dst))) {
1333 ren2 = item->util;
1334 clean_merge = 0;
1335 ren2->processed = 1;
1336 output(1, "CONFLICT (rename/rename): Renamed %s->%s in %s. "
1337 "Renamed %s->%s in %s",
1338 ren1_src, ren1_dst, branch1,
1339 ren2->pair->one->path, ren2->pair->two->path, branch2);
1340 conflict_rename_rename_2(ren1, branch1, ren2, branch2);
1341 } else
1342 try_merge = 1;
1344 if (try_merge) {
1345 struct diff_filespec *o, *a, *b;
1346 struct merge_file_info mfi;
1347 src_other.path = (char *)ren1_src;
1349 o = ren1->pair->one;
1350 if (a_renames == renames1) {
1351 a = ren1->pair->two;
1352 b = &src_other;
1353 } else {
1354 b = ren1->pair->two;
1355 a = &src_other;
1356 }
1357 mfi = merge_file(o, a, b,
1358 a_branch, b_branch);
1360 if (mfi.merge || !mfi.clean)
1361 output(1, "Renamed %s => %s", ren1_src, ren1_dst);
1362 if (mfi.merge)
1363 output(2, "Auto-merged %s", ren1_dst);
1364 if (!mfi.clean) {
1365 output(1, "CONFLICT (rename/modify): Merge conflict in %s",
1366 ren1_dst);
1367 clean_merge = 0;
1369 if (!index_only)
1370 update_stages(ren1_dst,
1371 o, a, b, 1);
1372 }
1373 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1374 }
1375 }
1376 }
1377 path_list_clear(&a_by_dst, 0);
1378 path_list_clear(&b_by_dst, 0);
1380 return clean_merge;
1381 }
1383 static unsigned char *has_sha(const unsigned char *sha)
1384 {
1385 return is_null_sha1(sha) ? NULL: (unsigned char *)sha;
1386 }
1388 /* Per entry merge function */
1389 static int process_entry(const char *path, struct stage_data *entry,
1390 const char *branch1,
1391 const char *branch2)
1392 {
1393 /*
1394 printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1395 print_index_entry("\tpath: ", entry);
1396 */
1397 int clean_merge = 1;
1398 unsigned char *o_sha = has_sha(entry->stages[1].sha);
1399 unsigned char *a_sha = has_sha(entry->stages[2].sha);
1400 unsigned char *b_sha = has_sha(entry->stages[3].sha);
1401 unsigned o_mode = entry->stages[1].mode;
1402 unsigned a_mode = entry->stages[2].mode;
1403 unsigned b_mode = entry->stages[3].mode;
1405 if (o_sha && (!a_sha || !b_sha)) {
1406 /* Case A: Deleted in one */
1407 if ((!a_sha && !b_sha) ||
1408 (sha_eq(a_sha, o_sha) && !b_sha) ||
1409 (!a_sha && sha_eq(b_sha, o_sha))) {
1410 /* Deleted in both or deleted in one and
1411 * unchanged in the other */
1412 if (a_sha)
1413 output(2, "Removed %s", path);
1414 /* do not touch working file if it did not exist */
1415 remove_file(1, path, !a_sha);
1416 } else {
1417 /* Deleted in one and changed in the other */
1418 clean_merge = 0;
1419 if (!a_sha) {
1420 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1421 "and modified in %s. Version %s of %s left in tree.",
1422 path, branch1,
1423 branch2, branch2, path);
1424 update_file(0, b_sha, b_mode, path);
1425 } else {
1426 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1427 "and modified in %s. Version %s of %s left in tree.",
1428 path, branch2,
1429 branch1, branch1, path);
1430 update_file(0, a_sha, a_mode, path);
1431 }
1432 }
1434 } else if ((!o_sha && a_sha && !b_sha) ||
1435 (!o_sha && !a_sha && b_sha)) {
1436 /* Case B: Added in one. */
1437 const char *add_branch;
1438 const char *other_branch;
1439 unsigned mode;
1440 const unsigned char *sha;
1441 const char *conf;
1443 if (a_sha) {
1444 add_branch = branch1;
1445 other_branch = branch2;
1446 mode = a_mode;
1447 sha = a_sha;
1448 conf = "file/directory";
1449 } else {
1450 add_branch = branch2;
1451 other_branch = branch1;
1452 mode = b_mode;
1453 sha = b_sha;
1454 conf = "directory/file";
1455 }
1456 if (path_list_has_path(¤t_directory_set, path)) {
1457 const char *new_path = unique_path(path, add_branch);
1458 clean_merge = 0;
1459 output(1, "CONFLICT (%s): There is a directory with name %s in %s. "
1460 "Added %s as %s",
1461 conf, path, other_branch, path, new_path);
1462 remove_file(0, path, 0);
1463 update_file(0, sha, mode, new_path);
1464 } else {
1465 output(2, "Added %s", path);
1466 update_file(1, sha, mode, path);
1467 }
1468 } else if (a_sha && b_sha) {
1469 /* Case C: Added in both (check for same permissions) and */
1470 /* case D: Modified in both, but differently. */
1471 const char *reason = "content";
1472 struct merge_file_info mfi;
1473 struct diff_filespec o, a, b;
1475 if (!o_sha) {
1476 reason = "add/add";
1477 o_sha = (unsigned char *)null_sha1;
1478 }
1479 output(2, "Auto-merged %s", path);
1480 o.path = a.path = b.path = (char *)path;
1481 hashcpy(o.sha1, o_sha);
1482 o.mode = o_mode;
1483 hashcpy(a.sha1, a_sha);
1484 a.mode = a_mode;
1485 hashcpy(b.sha1, b_sha);
1486 b.mode = b_mode;
1488 mfi = merge_file(&o, &a, &b,
1489 branch1, branch2);
1491 if (mfi.clean)
1492 update_file(1, mfi.sha, mfi.mode, path);
1493 else {
1494 clean_merge = 0;
1495 output(1, "CONFLICT (%s): Merge conflict in %s",
1496 reason, path);
1498 if (index_only)
1499 update_file(0, mfi.sha, mfi.mode, path);
1500 else
1501 update_file_flags(mfi.sha, mfi.mode, path,
1502 0 /* update_cache */, 1 /* update_working_directory */);
1503 }
1504 } else
1505 die("Fatal merge failure, shouldn't happen.");
1507 return clean_merge;
1508 }
1510 static int merge_trees(struct tree *head,
1511 struct tree *merge,
1512 struct tree *common,
1513 const char *branch1,
1514 const char *branch2,
1515 struct tree **result)
1516 {
1517 int code, clean;
1519 if (subtree_merge) {
1520 merge = shift_tree_object(head, merge);
1521 common = shift_tree_object(head, common);
1522 }
1524 if (sha_eq(common->object.sha1, merge->object.sha1)) {
1525 output(0, "Already uptodate!");
1526 *result = head;
1527 return 1;
1528 }
1530 code = git_merge_trees(index_only, common, head, merge);
1532 if (code != 0)
1533 die("merging of trees %s and %s failed",
1534 sha1_to_hex(head->object.sha1),
1535 sha1_to_hex(merge->object.sha1));
1537 if (unmerged_index()) {
1538 struct path_list *entries, *re_head, *re_merge;
1539 int i;
1540 path_list_clear(¤t_file_set, 1);
1541 path_list_clear(¤t_directory_set, 1);
1542 get_files_dirs(head);
1543 get_files_dirs(merge);
1545 entries = get_unmerged();
1546 re_head = get_renames(head, common, head, merge, entries);
1547 re_merge = get_renames(merge, common, head, merge, entries);
1548 clean = process_renames(re_head, re_merge,
1549 branch1, branch2);
1550 total_cnt += entries->nr;
1551 for (i = 0; i < entries->nr; i++, merged_cnt++) {
1552 const char *path = entries->items[i].path;
1553 struct stage_data *e = entries->items[i].util;
1554 if (!e->processed
1555 && !process_entry(path, e, branch1, branch2))
1556 clean = 0;
1557 if (do_progress)
1558 display_progress();
1559 }
1561 path_list_clear(re_merge, 0);
1562 path_list_clear(re_head, 0);
1563 path_list_clear(entries, 1);
1565 }
1566 else
1567 clean = 1;
1569 if (index_only)
1570 *result = git_write_tree();
1572 return clean;
1573 }
1575 static struct commit_list *reverse_commit_list(struct commit_list *list)
1576 {
1577 struct commit_list *next = NULL, *current, *backup;
1578 for (current = list; current; current = backup) {
1579 backup = current->next;
1580 current->next = next;
1581 next = current;
1582 }
1583 return next;
1584 }
1586 /*
1587 * Merge the commits h1 and h2, return the resulting virtual
1588 * commit object and a flag indicating the cleanness of the merge.
1589 */
1590 static int merge(struct commit *h1,
1591 struct commit *h2,
1592 const char *branch1,
1593 const char *branch2,
1594 struct commit_list *ca,
1595 struct commit **result)
1596 {
1597 struct commit_list *iter;
1598 struct commit *merged_common_ancestors;
1599 struct tree *mrtree;
1600 int clean;
1602 if (show(4)) {
1603 output(4, "Merging:");
1604 output_commit_title(h1);
1605 output_commit_title(h2);
1606 }
1608 if (!ca) {
1609 ca = get_merge_bases(h1, h2, 1);
1610 ca = reverse_commit_list(ca);
1611 }
1613 if (show(5)) {
1614 output(5, "found %u common ancestor(s):", commit_list_count(ca));
1615 for (iter = ca; iter; iter = iter->next)
1616 output_commit_title(iter->item);
1617 }
1619 merged_common_ancestors = pop_commit(&ca);
1620 if (merged_common_ancestors == NULL) {
1621 /* if there is no common ancestor, make an empty tree */
1622 struct tree *tree = xcalloc(1, sizeof(struct tree));
1624 tree->object.parsed = 1;
1625 tree->object.type = OBJ_TREE;
1626 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1627 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1628 }
1630 for (iter = ca; iter; iter = iter->next) {
1631 call_depth++;
1632 /*
1633 * When the merge fails, the result contains files
1634 * with conflict markers. The cleanness flag is
1635 * ignored, it was never actually used, as result of
1636 * merge_trees has always overwritten it: the committed
1637 * "conflicts" were already resolved.
1638 */
1639 discard_cache();
1640 merge(merged_common_ancestors, iter->item,
1641 "Temporary merge branch 1",
1642 "Temporary merge branch 2",
1643 NULL,
1644 &merged_common_ancestors);
1645 call_depth--;
1647 if (!merged_common_ancestors)
1648 die("merge returned no commit");
1649 }
1651 discard_cache();
1652 if (!call_depth) {
1653 read_cache();
1654 index_only = 0;
1655 } else
1656 index_only = 1;
1658 clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
1659 branch1, branch2, &mrtree);
1661 if (index_only) {
1662 *result = make_virtual_commit(mrtree, "merged tree");
1663 commit_list_insert(h1, &(*result)->parents);
1664 commit_list_insert(h2, &(*result)->parents->next);
1665 }
1666 if (!call_depth && do_progress) {
1667 /* Make sure we end at 100% */
1668 if (!total_cnt)
1669 total_cnt = 1;
1670 merged_cnt = total_cnt;
1671 progress_update = 1;
1672 display_progress();
1673 fputc('\n', stderr);
1674 }
1675 flush_output();
1676 return clean;
1677 }
1679 static const char *better_branch_name(const char *branch)
1680 {
1681 static char githead_env[8 + 40 + 1];
1682 char *name;
1684 if (strlen(branch) != 40)
1685 return branch;
1686 sprintf(githead_env, "GITHEAD_%s", branch);
1687 name = getenv(githead_env);
1688 return name ? name : branch;
1689 }
1691 static struct commit *get_ref(const char *ref)
1692 {
1693 unsigned char sha1[20];
1694 struct object *object;
1696 if (get_sha1(ref, sha1))
1697 die("Could not resolve ref '%s'", ref);
1698 object = deref_tag(parse_object(sha1), ref, strlen(ref));
1699 if (object->type == OBJ_TREE)
1700 return make_virtual_commit((struct tree*)object,
1701 better_branch_name(ref));
1702 if (object->type != OBJ_COMMIT)
1703 return NULL;
1704 if (parse_commit((struct commit *)object))
1705 die("Could not parse commit '%s'", sha1_to_hex(object->sha1));
1706 return (struct commit *)object;
1707 }
1709 static int merge_config(const char *var, const char *value)
1710 {
1711 if (!strcasecmp(var, "merge.verbosity")) {
1712 verbosity = git_config_int(var, value);
1713 return 0;
1714 }
1715 return git_default_config(var, value);
1716 }
1718 int main(int argc, char *argv[])
1719 {
1720 static const char *bases[20];
1721 static unsigned bases_count = 0;
1722 int i, clean;
1723 const char *branch1, *branch2;
1724 struct commit *result, *h1, *h2;
1725 struct commit_list *ca = NULL;
1726 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1727 int index_fd;
1729 if (argv[0]) {
1730 int namelen = strlen(argv[0]);
1731 if (8 < namelen &&
1732 !strcmp(argv[0] + namelen - 8, "-subtree"))
1733 subtree_merge = 1;
1734 }
1736 git_config(merge_config);
1737 if (getenv("GIT_MERGE_VERBOSITY"))
1738 verbosity = strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1740 if (argc < 4)
1741 die("Usage: %s <base>... -- <head> <remote> ...\n", argv[0]);
1743 for (i = 1; i < argc; ++i) {
1744 if (!strcmp(argv[i], "--"))
1745 break;
1746 if (bases_count < sizeof(bases)/sizeof(*bases))
1747 bases[bases_count++] = argv[i];
1748 }
1749 if (argc - i != 3) /* "--" "<head>" "<remote>" */
1750 die("Not handling anything other than two heads merge.");
1751 if (verbosity >= 5) {
1752 buffer_output = 0;
1753 do_progress = 0;
1754 }
1755 else
1756 do_progress = isatty(1);
1758 branch1 = argv[++i];
1759 branch2 = argv[++i];
1761 h1 = get_ref(branch1);
1762 h2 = get_ref(branch2);
1764 branch1 = better_branch_name(branch1);
1765 branch2 = better_branch_name(branch2);
1767 if (do_progress)
1768 setup_progress_signal();
1769 if (show(3))
1770 printf("Merging %s with %s\n", branch1, branch2);
1772 index_fd = hold_locked_index(lock, 1);
1774 for (i = 0; i < bases_count; i++) {
1775 struct commit *ancestor = get_ref(bases[i]);
1776 ca = commit_list_insert(ancestor, &ca);
1777 }
1778 clean = merge(h1, h2, branch1, branch2, ca, &result);
1780 if (active_cache_changed &&
1781 (write_cache(index_fd, active_cache, active_nr) ||
1782 close(index_fd) || commit_locked_index(lock)))
1783 die ("unable to write %s", get_index_file());
1785 return clean ? 0: 1;
1786 }