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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 "run-command.h"
15 #include "tag.h"
16 #include "unpack-trees.h"
17 #include "path-list.h"
18 #include "xdiff-interface.h"
19 #include "interpolate.h"
20 #include "attr.h"
21 #include "merge-recursive.h"
23 static int subtree_merge;
25 static struct tree *shift_tree_object(struct tree *one, struct tree *two)
26 {
27 unsigned char shifted[20];
29 /*
30 * NEEDSWORK: this limits the recursion depth to hardcoded
31 * value '2' to avoid excessive overhead.
32 */
33 shift_tree(one->object.sha1, two->object.sha1, shifted, 2);
34 if (!hashcmp(two->object.sha1, shifted))
35 return two;
36 return lookup_tree(shifted);
37 }
39 /*
40 * A virtual commit has
41 * - (const char *)commit->util set to the name, and
42 * - *(int *)commit->object.sha1 set to the virtual id.
43 */
45 static unsigned commit_list_count(const struct commit_list *l)
46 {
47 unsigned c = 0;
48 for (; l; l = l->next )
49 c++;
50 return c;
51 }
53 static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
54 {
55 struct commit *commit = xcalloc(1, sizeof(struct commit));
56 static unsigned virtual_id = 1;
57 commit->tree = tree;
58 commit->util = (void*)comment;
59 *(int*)commit->object.sha1 = virtual_id++;
60 /* avoid warnings */
61 commit->object.parsed = 1;
62 return commit;
63 }
65 /*
66 * Since we use get_tree_entry(), which does not put the read object into
67 * the object pool, we cannot rely on a == b.
68 */
69 static int sha_eq(const unsigned char *a, const unsigned char *b)
70 {
71 if (!a && !b)
72 return 2;
73 return a && b && hashcmp(a, b) == 0;
74 }
76 /*
77 * Since we want to write the index eventually, we cannot reuse the index
78 * for these (temporary) data.
79 */
80 struct stage_data
81 {
82 struct
83 {
84 unsigned mode;
85 unsigned char sha[20];
86 } stages[4];
87 unsigned processed:1;
88 };
90 static struct path_list current_file_set = {NULL, 0, 0, 1};
91 static struct path_list current_directory_set = {NULL, 0, 0, 1};
93 static int call_depth = 0;
94 static int verbosity = 2;
95 static int rename_limit = -1;
96 static int buffer_output = 1;
97 static struct strbuf obuf = STRBUF_INIT;
99 static int show(int v)
100 {
101 return (!call_depth && verbosity >= v) || verbosity >= 5;
102 }
104 static void flush_output(void)
105 {
106 if (obuf.len) {
107 fputs(obuf.buf, stdout);
108 strbuf_reset(&obuf);
109 }
110 }
112 static void output(int v, const char *fmt, ...)
113 {
114 int len;
115 va_list ap;
117 if (!show(v))
118 return;
120 strbuf_grow(&obuf, call_depth * 2 + 2);
121 memset(obuf.buf + obuf.len, ' ', call_depth * 2);
122 strbuf_setlen(&obuf, obuf.len + call_depth * 2);
124 va_start(ap, fmt);
125 len = vsnprintf(obuf.buf + obuf.len, strbuf_avail(&obuf), fmt, ap);
126 va_end(ap);
128 if (len < 0)
129 len = 0;
130 if (len >= strbuf_avail(&obuf)) {
131 strbuf_grow(&obuf, len + 2);
132 va_start(ap, fmt);
133 len = vsnprintf(obuf.buf + obuf.len, strbuf_avail(&obuf), fmt, ap);
134 va_end(ap);
135 if (len >= strbuf_avail(&obuf)) {
136 die("this should not happen, your snprintf is broken");
137 }
138 }
139 strbuf_setlen(&obuf, obuf.len + len);
140 strbuf_add(&obuf, "\n", 1);
141 if (!buffer_output)
142 flush_output();
143 }
145 static void output_commit_title(struct commit *commit)
146 {
147 int i;
148 flush_output();
149 for (i = call_depth; i--;)
150 fputs(" ", stdout);
151 if (commit->util)
152 printf("virtual %s\n", (char *)commit->util);
153 else {
154 printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
155 if (parse_commit(commit) != 0)
156 printf("(bad commit)\n");
157 else {
158 const char *s;
159 int len;
160 for (s = commit->buffer; *s; s++)
161 if (*s == '\n' && s[1] == '\n') {
162 s += 2;
163 break;
164 }
165 for (len = 0; s[len] && '\n' != s[len]; len++)
166 ; /* do nothing */
167 printf("%.*s\n", len, s);
168 }
169 }
170 }
172 static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
173 const char *path, int stage, int refresh, int options)
174 {
175 struct cache_entry *ce;
176 ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
177 if (!ce)
178 return error("addinfo_cache failed for path '%s'", path);
179 return add_cache_entry(ce, options);
180 }
182 /*
183 * This is a global variable which is used in a number of places but
184 * only written to in the 'merge' function.
185 *
186 * index_only == 1 => Don't leave any non-stage 0 entries in the cache and
187 * don't update the working directory.
188 * 0 => Leave unmerged entries in the cache and update
189 * the working directory.
190 */
191 static int index_only = 0;
193 static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
194 {
195 parse_tree(tree);
196 init_tree_desc(desc, tree->buffer, tree->size);
197 }
199 static int git_merge_trees(int index_only,
200 struct tree *common,
201 struct tree *head,
202 struct tree *merge)
203 {
204 int rc;
205 struct tree_desc t[3];
206 struct unpack_trees_options opts;
208 memset(&opts, 0, sizeof(opts));
209 if (index_only)
210 opts.index_only = 1;
211 else
212 opts.update = 1;
213 opts.merge = 1;
214 opts.head_idx = 2;
215 opts.fn = threeway_merge;
216 opts.index = &the_index;
218 init_tree_desc_from_tree(t+0, common);
219 init_tree_desc_from_tree(t+1, head);
220 init_tree_desc_from_tree(t+2, merge);
222 rc = unpack_trees(3, t, &opts);
223 cache_tree_free(&active_cache_tree);
224 return rc;
225 }
227 struct tree *write_tree_from_memory(void)
228 {
229 struct tree *result = NULL;
231 if (unmerged_cache()) {
232 int i;
233 output(0, "There are unmerged index entries:");
234 for (i = 0; i < active_nr; i++) {
235 struct cache_entry *ce = active_cache[i];
236 if (ce_stage(ce))
237 output(0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
238 }
239 return NULL;
240 }
242 if (!active_cache_tree)
243 active_cache_tree = cache_tree();
245 if (!cache_tree_fully_valid(active_cache_tree) &&
246 cache_tree_update(active_cache_tree,
247 active_cache, active_nr, 0, 0) < 0)
248 die("error building trees");
250 result = lookup_tree(active_cache_tree->sha1);
252 return result;
253 }
255 static int save_files_dirs(const unsigned char *sha1,
256 const char *base, int baselen, const char *path,
257 unsigned int mode, int stage)
258 {
259 int len = strlen(path);
260 char *newpath = xmalloc(baselen + len + 1);
261 memcpy(newpath, base, baselen);
262 memcpy(newpath + baselen, path, len);
263 newpath[baselen + len] = '\0';
265 if (S_ISDIR(mode))
266 path_list_insert(newpath, ¤t_directory_set);
267 else
268 path_list_insert(newpath, ¤t_file_set);
269 free(newpath);
271 return READ_TREE_RECURSIVE;
272 }
274 static int get_files_dirs(struct tree *tree)
275 {
276 int n;
277 if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs) != 0)
278 return 0;
279 n = current_file_set.nr + current_directory_set.nr;
280 return n;
281 }
283 /*
284 * Returns an index_entry instance which doesn't have to correspond to
285 * a real cache entry in Git's index.
286 */
287 static struct stage_data *insert_stage_data(const char *path,
288 struct tree *o, struct tree *a, struct tree *b,
289 struct path_list *entries)
290 {
291 struct path_list_item *item;
292 struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
293 get_tree_entry(o->object.sha1, path,
294 e->stages[1].sha, &e->stages[1].mode);
295 get_tree_entry(a->object.sha1, path,
296 e->stages[2].sha, &e->stages[2].mode);
297 get_tree_entry(b->object.sha1, path,
298 e->stages[3].sha, &e->stages[3].mode);
299 item = path_list_insert(path, entries);
300 item->util = e;
301 return e;
302 }
304 /*
305 * Create a dictionary mapping file names to stage_data objects. The
306 * dictionary contains one entry for every path with a non-zero stage entry.
307 */
308 static struct path_list *get_unmerged(void)
309 {
310 struct path_list *unmerged = xcalloc(1, sizeof(struct path_list));
311 int i;
313 unmerged->strdup_paths = 1;
315 for (i = 0; i < active_nr; i++) {
316 struct path_list_item *item;
317 struct stage_data *e;
318 struct cache_entry *ce = active_cache[i];
319 if (!ce_stage(ce))
320 continue;
322 item = path_list_lookup(ce->name, unmerged);
323 if (!item) {
324 item = path_list_insert(ce->name, unmerged);
325 item->util = xcalloc(1, sizeof(struct stage_data));
326 }
327 e = item->util;
328 e->stages[ce_stage(ce)].mode = ce->ce_mode;
329 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
330 }
332 return unmerged;
333 }
335 struct rename
336 {
337 struct diff_filepair *pair;
338 struct stage_data *src_entry;
339 struct stage_data *dst_entry;
340 unsigned processed:1;
341 };
343 /*
344 * Get information of all renames which occurred between 'o_tree' and
345 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
346 * 'b_tree') to be able to associate the correct cache entries with
347 * the rename information. 'tree' is always equal to either a_tree or b_tree.
348 */
349 static struct path_list *get_renames(struct tree *tree,
350 struct tree *o_tree,
351 struct tree *a_tree,
352 struct tree *b_tree,
353 struct path_list *entries)
354 {
355 int i;
356 struct path_list *renames;
357 struct diff_options opts;
359 renames = xcalloc(1, sizeof(struct path_list));
360 diff_setup(&opts);
361 DIFF_OPT_SET(&opts, RECURSIVE);
362 opts.detect_rename = DIFF_DETECT_RENAME;
363 opts.rename_limit = rename_limit;
364 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
365 if (diff_setup_done(&opts) < 0)
366 die("diff setup failed");
367 diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
368 diffcore_std(&opts);
369 for (i = 0; i < diff_queued_diff.nr; ++i) {
370 struct path_list_item *item;
371 struct rename *re;
372 struct diff_filepair *pair = diff_queued_diff.queue[i];
373 if (pair->status != 'R') {
374 diff_free_filepair(pair);
375 continue;
376 }
377 re = xmalloc(sizeof(*re));
378 re->processed = 0;
379 re->pair = pair;
380 item = path_list_lookup(re->pair->one->path, entries);
381 if (!item)
382 re->src_entry = insert_stage_data(re->pair->one->path,
383 o_tree, a_tree, b_tree, entries);
384 else
385 re->src_entry = item->util;
387 item = path_list_lookup(re->pair->two->path, entries);
388 if (!item)
389 re->dst_entry = insert_stage_data(re->pair->two->path,
390 o_tree, a_tree, b_tree, entries);
391 else
392 re->dst_entry = item->util;
393 item = path_list_insert(pair->one->path, renames);
394 item->util = re;
395 }
396 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
397 diff_queued_diff.nr = 0;
398 diff_flush(&opts);
399 return renames;
400 }
402 static int update_stages(const char *path, struct diff_filespec *o,
403 struct diff_filespec *a, struct diff_filespec *b,
404 int clear)
405 {
406 int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
407 if (clear)
408 if (remove_file_from_cache(path))
409 return -1;
410 if (o)
411 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
412 return -1;
413 if (a)
414 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
415 return -1;
416 if (b)
417 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
418 return -1;
419 return 0;
420 }
422 static int remove_path(const char *name)
423 {
424 int ret;
425 char *slash, *dirs;
427 ret = unlink(name);
428 if (ret)
429 return ret;
430 dirs = xstrdup(name);
431 while ((slash = strrchr(name, '/'))) {
432 *slash = '\0';
433 if (rmdir(name) != 0)
434 break;
435 }
436 free(dirs);
437 return ret;
438 }
440 static int remove_file(int clean, const char *path, int no_wd)
441 {
442 int update_cache = index_only || clean;
443 int update_working_directory = !index_only && !no_wd;
445 if (update_cache) {
446 if (remove_file_from_cache(path))
447 return -1;
448 }
449 if (update_working_directory) {
450 unlink(path);
451 if (errno != ENOENT || errno != EISDIR)
452 return -1;
453 remove_path(path);
454 }
455 return 0;
456 }
458 static char *unique_path(const char *path, const char *branch)
459 {
460 char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
461 int suffix = 0;
462 struct stat st;
463 char *p = newpath + strlen(path);
464 strcpy(newpath, path);
465 *(p++) = '~';
466 strcpy(p, branch);
467 for (; *p; ++p)
468 if ('/' == *p)
469 *p = '_';
470 while (path_list_has_path(¤t_file_set, newpath) ||
471 path_list_has_path(¤t_directory_set, newpath) ||
472 lstat(newpath, &st) == 0)
473 sprintf(p, "_%d", suffix++);
475 path_list_insert(newpath, ¤t_file_set);
476 return newpath;
477 }
479 static int mkdir_p(const char *path, unsigned long mode)
480 {
481 /* path points to cache entries, so xstrdup before messing with it */
482 char *buf = xstrdup(path);
483 int result = safe_create_leading_directories(buf);
484 free(buf);
485 return result;
486 }
488 static void flush_buffer(int fd, const char *buf, unsigned long size)
489 {
490 while (size > 0) {
491 long ret = write_in_full(fd, buf, size);
492 if (ret < 0) {
493 /* Ignore epipe */
494 if (errno == EPIPE)
495 break;
496 die("merge-recursive: %s", strerror(errno));
497 } else if (!ret) {
498 die("merge-recursive: disk full?");
499 }
500 size -= ret;
501 buf += ret;
502 }
503 }
505 static int make_room_for_path(const char *path)
506 {
507 int status;
508 const char *msg = "failed to create path '%s'%s";
510 status = mkdir_p(path, 0777);
511 if (status) {
512 if (status == -3) {
513 /* something else exists */
514 error(msg, path, ": perhaps a D/F conflict?");
515 return -1;
516 }
517 die(msg, path, "");
518 }
520 /* Successful unlink is good.. */
521 if (!unlink(path))
522 return 0;
523 /* .. and so is no existing file */
524 if (errno == ENOENT)
525 return 0;
526 /* .. but not some other error (who really cares what?) */
527 return error(msg, path, ": perhaps a D/F conflict?");
528 }
530 static void update_file_flags(const unsigned char *sha,
531 unsigned mode,
532 const char *path,
533 int update_cache,
534 int update_wd)
535 {
536 if (index_only)
537 update_wd = 0;
539 if (update_wd) {
540 enum object_type type;
541 void *buf;
542 unsigned long size;
544 if (S_ISGITLINK(mode))
545 die("cannot read object %s '%s': It is a submodule!",
546 sha1_to_hex(sha), path);
548 buf = read_sha1_file(sha, &type, &size);
549 if (!buf)
550 die("cannot read object %s '%s'", sha1_to_hex(sha), path);
551 if (type != OBJ_BLOB)
552 die("blob expected for %s '%s'", sha1_to_hex(sha), path);
554 if (make_room_for_path(path) < 0) {
555 update_wd = 0;
556 goto update_index;
557 }
558 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
559 int fd;
560 if (mode & 0100)
561 mode = 0777;
562 else
563 mode = 0666;
564 fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
565 if (fd < 0)
566 die("failed to open %s: %s", path, strerror(errno));
567 flush_buffer(fd, buf, size);
568 close(fd);
569 } else if (S_ISLNK(mode)) {
570 char *lnk = xmemdupz(buf, size);
571 mkdir_p(path, 0777);
572 unlink(path);
573 symlink(lnk, path);
574 free(lnk);
575 } else
576 die("do not know what to do with %06o %s '%s'",
577 mode, sha1_to_hex(sha), path);
578 }
579 update_index:
580 if (update_cache)
581 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
582 }
584 static void update_file(int clean,
585 const unsigned char *sha,
586 unsigned mode,
587 const char *path)
588 {
589 update_file_flags(sha, mode, path, index_only || clean, !index_only);
590 }
592 /* Low level file merging, update and removal */
594 struct merge_file_info
595 {
596 unsigned char sha[20];
597 unsigned mode;
598 unsigned clean:1,
599 merge:1;
600 };
602 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
603 {
604 unsigned long size;
605 enum object_type type;
607 if (!hashcmp(sha1, null_sha1)) {
608 mm->ptr = xstrdup("");
609 mm->size = 0;
610 return;
611 }
613 mm->ptr = read_sha1_file(sha1, &type, &size);
614 if (!mm->ptr || type != OBJ_BLOB)
615 die("unable to read blob object %s", sha1_to_hex(sha1));
616 mm->size = size;
617 }
619 /*
620 * Customizable low-level merge drivers support.
621 */
623 struct ll_merge_driver;
624 typedef int (*ll_merge_fn)(const struct ll_merge_driver *,
625 const char *path,
626 mmfile_t *orig,
627 mmfile_t *src1, const char *name1,
628 mmfile_t *src2, const char *name2,
629 mmbuffer_t *result);
631 struct ll_merge_driver {
632 const char *name;
633 const char *description;
634 ll_merge_fn fn;
635 const char *recursive;
636 struct ll_merge_driver *next;
637 char *cmdline;
638 };
640 /*
641 * Built-in low-levels
642 */
643 static int ll_binary_merge(const struct ll_merge_driver *drv_unused,
644 const char *path_unused,
645 mmfile_t *orig,
646 mmfile_t *src1, const char *name1,
647 mmfile_t *src2, const char *name2,
648 mmbuffer_t *result)
649 {
650 /*
651 * The tentative merge result is "ours" for the final round,
652 * or common ancestor for an internal merge. Still return
653 * "conflicted merge" status.
654 */
655 mmfile_t *stolen = index_only ? orig : src1;
657 result->ptr = stolen->ptr;
658 result->size = stolen->size;
659 stolen->ptr = NULL;
660 return 1;
661 }
663 static int ll_xdl_merge(const struct ll_merge_driver *drv_unused,
664 const char *path_unused,
665 mmfile_t *orig,
666 mmfile_t *src1, const char *name1,
667 mmfile_t *src2, const char *name2,
668 mmbuffer_t *result)
669 {
670 xpparam_t xpp;
672 if (buffer_is_binary(orig->ptr, orig->size) ||
673 buffer_is_binary(src1->ptr, src1->size) ||
674 buffer_is_binary(src2->ptr, src2->size)) {
675 warning("Cannot merge binary files: %s vs. %s\n",
676 name1, name2);
677 return ll_binary_merge(drv_unused, path_unused,
678 orig, src1, name1,
679 src2, name2,
680 result);
681 }
683 memset(&xpp, 0, sizeof(xpp));
684 return xdl_merge(orig,
685 src1, name1,
686 src2, name2,
687 &xpp, XDL_MERGE_ZEALOUS,
688 result);
689 }
691 static int ll_union_merge(const struct ll_merge_driver *drv_unused,
692 const char *path_unused,
693 mmfile_t *orig,
694 mmfile_t *src1, const char *name1,
695 mmfile_t *src2, const char *name2,
696 mmbuffer_t *result)
697 {
698 char *src, *dst;
699 long size;
700 const int marker_size = 7;
702 int status = ll_xdl_merge(drv_unused, path_unused,
703 orig, src1, NULL, src2, NULL, result);
704 if (status <= 0)
705 return status;
706 size = result->size;
707 src = dst = result->ptr;
708 while (size) {
709 char ch;
710 if ((marker_size < size) &&
711 (*src == '<' || *src == '=' || *src == '>')) {
712 int i;
713 ch = *src;
714 for (i = 0; i < marker_size; i++)
715 if (src[i] != ch)
716 goto not_a_marker;
717 if (src[marker_size] != '\n')
718 goto not_a_marker;
719 src += marker_size + 1;
720 size -= marker_size + 1;
721 continue;
722 }
723 not_a_marker:
724 do {
725 ch = *src++;
726 *dst++ = ch;
727 size--;
728 } while (ch != '\n' && size);
729 }
730 result->size = dst - result->ptr;
731 return 0;
732 }
734 #define LL_BINARY_MERGE 0
735 #define LL_TEXT_MERGE 1
736 #define LL_UNION_MERGE 2
737 static struct ll_merge_driver ll_merge_drv[] = {
738 { "binary", "built-in binary merge", ll_binary_merge },
739 { "text", "built-in 3-way text merge", ll_xdl_merge },
740 { "union", "built-in union merge", ll_union_merge },
741 };
743 static void create_temp(mmfile_t *src, char *path)
744 {
745 int fd;
747 strcpy(path, ".merge_file_XXXXXX");
748 fd = xmkstemp(path);
749 if (write_in_full(fd, src->ptr, src->size) != src->size)
750 die("unable to write temp-file");
751 close(fd);
752 }
754 /*
755 * User defined low-level merge driver support.
756 */
757 static int ll_ext_merge(const struct ll_merge_driver *fn,
758 const char *path,
759 mmfile_t *orig,
760 mmfile_t *src1, const char *name1,
761 mmfile_t *src2, const char *name2,
762 mmbuffer_t *result)
763 {
764 char temp[3][50];
765 char cmdbuf[2048];
766 struct interp table[] = {
767 { "%O" },
768 { "%A" },
769 { "%B" },
770 };
771 struct child_process child;
772 const char *args[20];
773 int status, fd, i;
774 struct stat st;
776 if (fn->cmdline == NULL)
777 die("custom merge driver %s lacks command line.", fn->name);
779 result->ptr = NULL;
780 result->size = 0;
781 create_temp(orig, temp[0]);
782 create_temp(src1, temp[1]);
783 create_temp(src2, temp[2]);
785 interp_set_entry(table, 0, temp[0]);
786 interp_set_entry(table, 1, temp[1]);
787 interp_set_entry(table, 2, temp[2]);
789 output(1, "merging %s using %s", path,
790 fn->description ? fn->description : fn->name);
792 interpolate(cmdbuf, sizeof(cmdbuf), fn->cmdline, table, 3);
794 memset(&child, 0, sizeof(child));
795 child.argv = args;
796 args[0] = "sh";
797 args[1] = "-c";
798 args[2] = cmdbuf;
799 args[3] = NULL;
801 status = run_command(&child);
802 if (status < -ERR_RUN_COMMAND_FORK)
803 ; /* failure in run-command */
804 else
805 status = -status;
806 fd = open(temp[1], O_RDONLY);
807 if (fd < 0)
808 goto bad;
809 if (fstat(fd, &st))
810 goto close_bad;
811 result->size = st.st_size;
812 result->ptr = xmalloc(result->size + 1);
813 if (read_in_full(fd, result->ptr, result->size) != result->size) {
814 free(result->ptr);
815 result->ptr = NULL;
816 result->size = 0;
817 }
818 close_bad:
819 close(fd);
820 bad:
821 for (i = 0; i < 3; i++)
822 unlink(temp[i]);
823 return status;
824 }
826 /*
827 * merge.default and merge.driver configuration items
828 */
829 static struct ll_merge_driver *ll_user_merge, **ll_user_merge_tail;
830 static const char *default_ll_merge;
832 static int read_merge_config(const char *var, const char *value)
833 {
834 struct ll_merge_driver *fn;
835 const char *ep, *name;
836 int namelen;
838 if (!strcmp(var, "merge.default")) {
839 if (!value)
840 return config_error_nonbool(var);
841 default_ll_merge = strdup(value);
842 return 0;
843 }
845 /*
846 * We are not interested in anything but "merge.<name>.variable";
847 * especially, we do not want to look at variables such as
848 * "merge.summary", "merge.tool", and "merge.verbosity".
849 */
850 if (prefixcmp(var, "merge.") || (ep = strrchr(var, '.')) == var + 5)
851 return 0;
853 /*
854 * Find existing one as we might be processing merge.<name>.var2
855 * after seeing merge.<name>.var1.
856 */
857 name = var + 6;
858 namelen = ep - name;
859 for (fn = ll_user_merge; fn; fn = fn->next)
860 if (!strncmp(fn->name, name, namelen) && !fn->name[namelen])
861 break;
862 if (!fn) {
863 fn = xcalloc(1, sizeof(struct ll_merge_driver));
864 fn->name = xmemdupz(name, namelen);
865 fn->fn = ll_ext_merge;
866 *ll_user_merge_tail = fn;
867 ll_user_merge_tail = &(fn->next);
868 }
870 ep++;
872 if (!strcmp("name", ep)) {
873 if (!value)
874 return config_error_nonbool(var);
875 fn->description = strdup(value);
876 return 0;
877 }
879 if (!strcmp("driver", ep)) {
880 if (!value)
881 return config_error_nonbool(var);
882 /*
883 * merge.<name>.driver specifies the command line:
884 *
885 * command-line
886 *
887 * The command-line will be interpolated with the following
888 * tokens and is given to the shell:
889 *
890 * %O - temporary file name for the merge base.
891 * %A - temporary file name for our version.
892 * %B - temporary file name for the other branches' version.
893 *
894 * The external merge driver should write the results in the
895 * file named by %A, and signal that it has done with zero exit
896 * status.
897 */
898 fn->cmdline = strdup(value);
899 return 0;
900 }
902 if (!strcmp("recursive", ep)) {
903 if (!value)
904 return config_error_nonbool(var);
905 fn->recursive = strdup(value);
906 return 0;
907 }
909 return 0;
910 }
912 static void initialize_ll_merge(void)
913 {
914 if (ll_user_merge_tail)
915 return;
916 ll_user_merge_tail = &ll_user_merge;
917 git_config(read_merge_config);
918 }
920 static const struct ll_merge_driver *find_ll_merge_driver(const char *merge_attr)
921 {
922 struct ll_merge_driver *fn;
923 const char *name;
924 int i;
926 initialize_ll_merge();
928 if (ATTR_TRUE(merge_attr))
929 return &ll_merge_drv[LL_TEXT_MERGE];
930 else if (ATTR_FALSE(merge_attr))
931 return &ll_merge_drv[LL_BINARY_MERGE];
932 else if (ATTR_UNSET(merge_attr)) {
933 if (!default_ll_merge)
934 return &ll_merge_drv[LL_TEXT_MERGE];
935 else
936 name = default_ll_merge;
937 }
938 else
939 name = merge_attr;
941 for (fn = ll_user_merge; fn; fn = fn->next)
942 if (!strcmp(fn->name, name))
943 return fn;
945 for (i = 0; i < ARRAY_SIZE(ll_merge_drv); i++)
946 if (!strcmp(ll_merge_drv[i].name, name))
947 return &ll_merge_drv[i];
949 /* default to the 3-way */
950 return &ll_merge_drv[LL_TEXT_MERGE];
951 }
953 static const char *git_path_check_merge(const char *path)
954 {
955 static struct git_attr_check attr_merge_check;
957 if (!attr_merge_check.attr)
958 attr_merge_check.attr = git_attr("merge", 5);
960 if (git_checkattr(path, 1, &attr_merge_check))
961 return NULL;
962 return attr_merge_check.value;
963 }
965 static int ll_merge(mmbuffer_t *result_buf,
966 struct diff_filespec *o,
967 struct diff_filespec *a,
968 struct diff_filespec *b,
969 const char *branch1,
970 const char *branch2)
971 {
972 mmfile_t orig, src1, src2;
973 char *name1, *name2;
974 int merge_status;
975 const char *ll_driver_name;
976 const struct ll_merge_driver *driver;
978 name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
979 name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
981 fill_mm(o->sha1, &orig);
982 fill_mm(a->sha1, &src1);
983 fill_mm(b->sha1, &src2);
985 ll_driver_name = git_path_check_merge(a->path);
986 driver = find_ll_merge_driver(ll_driver_name);
988 if (index_only && driver->recursive)
989 driver = find_ll_merge_driver(driver->recursive);
990 merge_status = driver->fn(driver, a->path,
991 &orig, &src1, name1, &src2, name2,
992 result_buf);
994 free(name1);
995 free(name2);
996 free(orig.ptr);
997 free(src1.ptr);
998 free(src2.ptr);
999 return merge_status;
1000 }
1002 static struct merge_file_info merge_file(struct diff_filespec *o,
1003 struct diff_filespec *a, struct diff_filespec *b,
1004 const char *branch1, const char *branch2)
1005 {
1006 struct merge_file_info result;
1007 result.merge = 0;
1008 result.clean = 1;
1010 if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
1011 result.clean = 0;
1012 if (S_ISREG(a->mode)) {
1013 result.mode = a->mode;
1014 hashcpy(result.sha, a->sha1);
1015 } else {
1016 result.mode = b->mode;
1017 hashcpy(result.sha, b->sha1);
1018 }
1019 } else {
1020 if (!sha_eq(a->sha1, o->sha1) && !sha_eq(b->sha1, o->sha1))
1021 result.merge = 1;
1023 result.mode = a->mode == o->mode ? b->mode: a->mode;
1025 if (sha_eq(a->sha1, o->sha1))
1026 hashcpy(result.sha, b->sha1);
1027 else if (sha_eq(b->sha1, o->sha1))
1028 hashcpy(result.sha, a->sha1);
1029 else if (S_ISREG(a->mode)) {
1030 mmbuffer_t result_buf;
1031 int merge_status;
1033 merge_status = ll_merge(&result_buf, o, a, b,
1034 branch1, branch2);
1036 if ((merge_status < 0) || !result_buf.ptr)
1037 die("Failed to execute internal merge");
1039 if (write_sha1_file(result_buf.ptr, result_buf.size,
1040 blob_type, result.sha))
1041 die("Unable to add %s to database",
1042 a->path);
1044 free(result_buf.ptr);
1045 result.clean = (merge_status == 0);
1046 } else if (S_ISGITLINK(a->mode)) {
1047 result.clean = 0;
1048 hashcpy(result.sha, a->sha1);
1049 } else if (S_ISLNK(a->mode)) {
1050 hashcpy(result.sha, a->sha1);
1052 if (!sha_eq(a->sha1, b->sha1))
1053 result.clean = 0;
1054 } else {
1055 die("unsupported object type in the tree");
1056 }
1057 }
1059 return result;
1060 }
1062 static void conflict_rename_rename(struct rename *ren1,
1063 const char *branch1,
1064 struct rename *ren2,
1065 const char *branch2)
1066 {
1067 char *del[2];
1068 int delp = 0;
1069 const char *ren1_dst = ren1->pair->two->path;
1070 const char *ren2_dst = ren2->pair->two->path;
1071 const char *dst_name1 = ren1_dst;
1072 const char *dst_name2 = ren2_dst;
1073 if (path_list_has_path(¤t_directory_set, ren1_dst)) {
1074 dst_name1 = del[delp++] = unique_path(ren1_dst, branch1);
1075 output(1, "%s is a directory in %s added as %s instead",
1076 ren1_dst, branch2, dst_name1);
1077 remove_file(0, ren1_dst, 0);
1078 }
1079 if (path_list_has_path(¤t_directory_set, ren2_dst)) {
1080 dst_name2 = del[delp++] = unique_path(ren2_dst, branch2);
1081 output(1, "%s is a directory in %s added as %s instead",
1082 ren2_dst, branch1, dst_name2);
1083 remove_file(0, ren2_dst, 0);
1084 }
1085 if (index_only) {
1086 remove_file_from_cache(dst_name1);
1087 remove_file_from_cache(dst_name2);
1088 /*
1089 * Uncomment to leave the conflicting names in the resulting tree
1090 *
1091 * update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
1092 * update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
1093 */
1094 } else {
1095 update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
1096 update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
1097 }
1098 while (delp--)
1099 free(del[delp]);
1100 }
1102 static void conflict_rename_dir(struct rename *ren1,
1103 const char *branch1)
1104 {
1105 char *new_path = unique_path(ren1->pair->two->path, branch1);
1106 output(1, "Renamed %s to %s instead", ren1->pair->one->path, new_path);
1107 remove_file(0, ren1->pair->two->path, 0);
1108 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
1109 free(new_path);
1110 }
1112 static void conflict_rename_rename_2(struct rename *ren1,
1113 const char *branch1,
1114 struct rename *ren2,
1115 const char *branch2)
1116 {
1117 char *new_path1 = unique_path(ren1->pair->two->path, branch1);
1118 char *new_path2 = unique_path(ren2->pair->two->path, branch2);
1119 output(1, "Renamed %s to %s and %s to %s instead",
1120 ren1->pair->one->path, new_path1,
1121 ren2->pair->one->path, new_path2);
1122 remove_file(0, ren1->pair->two->path, 0);
1123 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
1124 update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
1125 free(new_path2);
1126 free(new_path1);
1127 }
1129 static int process_renames(struct path_list *a_renames,
1130 struct path_list *b_renames,
1131 const char *a_branch,
1132 const char *b_branch)
1133 {
1134 int clean_merge = 1, i, j;
1135 struct path_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
1136 const struct rename *sre;
1138 for (i = 0; i < a_renames->nr; i++) {
1139 sre = a_renames->items[i].util;
1140 path_list_insert(sre->pair->two->path, &a_by_dst)->util
1141 = sre->dst_entry;
1142 }
1143 for (i = 0; i < b_renames->nr; i++) {
1144 sre = b_renames->items[i].util;
1145 path_list_insert(sre->pair->two->path, &b_by_dst)->util
1146 = sre->dst_entry;
1147 }
1149 for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
1150 int compare;
1151 char *src;
1152 struct path_list *renames1, *renames2, *renames2Dst;
1153 struct rename *ren1 = NULL, *ren2 = NULL;
1154 const char *branch1, *branch2;
1155 const char *ren1_src, *ren1_dst;
1157 if (i >= a_renames->nr) {
1158 compare = 1;
1159 ren2 = b_renames->items[j++].util;
1160 } else if (j >= b_renames->nr) {
1161 compare = -1;
1162 ren1 = a_renames->items[i++].util;
1163 } else {
1164 compare = strcmp(a_renames->items[i].path,
1165 b_renames->items[j].path);
1166 if (compare <= 0)
1167 ren1 = a_renames->items[i++].util;
1168 if (compare >= 0)
1169 ren2 = b_renames->items[j++].util;
1170 }
1172 /* TODO: refactor, so that 1/2 are not needed */
1173 if (ren1) {
1174 renames1 = a_renames;
1175 renames2 = b_renames;
1176 renames2Dst = &b_by_dst;
1177 branch1 = a_branch;
1178 branch2 = b_branch;
1179 } else {
1180 struct rename *tmp;
1181 renames1 = b_renames;
1182 renames2 = a_renames;
1183 renames2Dst = &a_by_dst;
1184 branch1 = b_branch;
1185 branch2 = a_branch;
1186 tmp = ren2;
1187 ren2 = ren1;
1188 ren1 = tmp;
1189 }
1190 src = ren1->pair->one->path;
1192 ren1->dst_entry->processed = 1;
1193 ren1->src_entry->processed = 1;
1195 if (ren1->processed)
1196 continue;
1197 ren1->processed = 1;
1199 ren1_src = ren1->pair->one->path;
1200 ren1_dst = ren1->pair->two->path;
1202 if (ren2) {
1203 const char *ren2_src = ren2->pair->one->path;
1204 const char *ren2_dst = ren2->pair->two->path;
1205 /* Renamed in 1 and renamed in 2 */
1206 if (strcmp(ren1_src, ren2_src) != 0)
1207 die("ren1.src != ren2.src");
1208 ren2->dst_entry->processed = 1;
1209 ren2->processed = 1;
1210 if (strcmp(ren1_dst, ren2_dst) != 0) {
1211 clean_merge = 0;
1212 output(1, "CONFLICT (rename/rename): "
1213 "Rename \"%s\"->\"%s\" in branch \"%s\" "
1214 "rename \"%s\"->\"%s\" in \"%s\"%s",
1215 src, ren1_dst, branch1,
1216 src, ren2_dst, branch2,
1217 index_only ? " (left unresolved)": "");
1218 if (index_only) {
1219 remove_file_from_cache(src);
1220 update_file(0, ren1->pair->one->sha1,
1221 ren1->pair->one->mode, src);
1222 }
1223 conflict_rename_rename(ren1, branch1, ren2, branch2);
1224 } else {
1225 struct merge_file_info mfi;
1226 remove_file(1, ren1_src, 1);
1227 mfi = merge_file(ren1->pair->one,
1228 ren1->pair->two,
1229 ren2->pair->two,
1230 branch1,
1231 branch2);
1232 if (mfi.merge || !mfi.clean)
1233 output(1, "Renamed %s->%s", src, ren1_dst);
1235 if (mfi.merge)
1236 output(2, "Auto-merged %s", ren1_dst);
1238 if (!mfi.clean) {
1239 output(1, "CONFLICT (content): merge conflict in %s",
1240 ren1_dst);
1241 clean_merge = 0;
1243 if (!index_only)
1244 update_stages(ren1_dst,
1245 ren1->pair->one,
1246 ren1->pair->two,
1247 ren2->pair->two,
1248 1 /* clear */);
1249 }
1250 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1251 }
1252 } else {
1253 /* Renamed in 1, maybe changed in 2 */
1254 struct path_list_item *item;
1255 /* we only use sha1 and mode of these */
1256 struct diff_filespec src_other, dst_other;
1257 int try_merge, stage = a_renames == renames1 ? 3: 2;
1259 remove_file(1, ren1_src, index_only || stage == 3);
1261 hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
1262 src_other.mode = ren1->src_entry->stages[stage].mode;
1263 hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
1264 dst_other.mode = ren1->dst_entry->stages[stage].mode;
1266 try_merge = 0;
1268 if (path_list_has_path(¤t_directory_set, ren1_dst)) {
1269 clean_merge = 0;
1270 output(1, "CONFLICT (rename/directory): Renamed %s->%s in %s "
1271 " directory %s added in %s",
1272 ren1_src, ren1_dst, branch1,
1273 ren1_dst, branch2);
1274 conflict_rename_dir(ren1, branch1);
1275 } else if (sha_eq(src_other.sha1, null_sha1)) {
1276 clean_merge = 0;
1277 output(1, "CONFLICT (rename/delete): Renamed %s->%s in %s "
1278 "and deleted in %s",
1279 ren1_src, ren1_dst, branch1,
1280 branch2);
1281 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
1282 } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1283 const char *new_path;
1284 clean_merge = 0;
1285 try_merge = 1;
1286 output(1, "CONFLICT (rename/add): Renamed %s->%s in %s. "
1287 "%s added in %s",
1288 ren1_src, ren1_dst, branch1,
1289 ren1_dst, branch2);
1290 new_path = unique_path(ren1_dst, branch2);
1291 output(1, "Added as %s instead", new_path);
1292 update_file(0, dst_other.sha1, dst_other.mode, new_path);
1293 } else if ((item = path_list_lookup(ren1_dst, renames2Dst))) {
1294 ren2 = item->util;
1295 clean_merge = 0;
1296 ren2->processed = 1;
1297 output(1, "CONFLICT (rename/rename): Renamed %s->%s in %s. "
1298 "Renamed %s->%s in %s",
1299 ren1_src, ren1_dst, branch1,
1300 ren2->pair->one->path, ren2->pair->two->path, branch2);
1301 conflict_rename_rename_2(ren1, branch1, ren2, branch2);
1302 } else
1303 try_merge = 1;
1305 if (try_merge) {
1306 struct diff_filespec *o, *a, *b;
1307 struct merge_file_info mfi;
1308 src_other.path = (char *)ren1_src;
1310 o = ren1->pair->one;
1311 if (a_renames == renames1) {
1312 a = ren1->pair->two;
1313 b = &src_other;
1314 } else {
1315 b = ren1->pair->two;
1316 a = &src_other;
1317 }
1318 mfi = merge_file(o, a, b,
1319 a_branch, b_branch);
1321 if (mfi.clean &&
1322 sha_eq(mfi.sha, ren1->pair->two->sha1) &&
1323 mfi.mode == ren1->pair->two->mode)
1324 /*
1325 * This messaged is part of
1326 * t6022 test. If you change
1327 * it update the test too.
1328 */
1329 output(3, "Skipped %s (merged same as existing)", ren1_dst);
1330 else {
1331 if (mfi.merge || !mfi.clean)
1332 output(1, "Renamed %s => %s", ren1_src, ren1_dst);
1333 if (mfi.merge)
1334 output(2, "Auto-merged %s", ren1_dst);
1335 if (!mfi.clean) {
1336 output(1, "CONFLICT (rename/modify): Merge conflict in %s",
1337 ren1_dst);
1338 clean_merge = 0;
1340 if (!index_only)
1341 update_stages(ren1_dst,
1342 o, a, b, 1);
1343 }
1344 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1345 }
1346 }
1347 }
1348 }
1349 path_list_clear(&a_by_dst, 0);
1350 path_list_clear(&b_by_dst, 0);
1352 return clean_merge;
1353 }
1355 static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1356 {
1357 return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1358 }
1360 /* Per entry merge function */
1361 static int process_entry(const char *path, struct stage_data *entry,
1362 const char *branch1,
1363 const char *branch2)
1364 {
1365 /*
1366 printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1367 print_index_entry("\tpath: ", entry);
1368 */
1369 int clean_merge = 1;
1370 unsigned o_mode = entry->stages[1].mode;
1371 unsigned a_mode = entry->stages[2].mode;
1372 unsigned b_mode = entry->stages[3].mode;
1373 unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1374 unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1375 unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1377 if (o_sha && (!a_sha || !b_sha)) {
1378 /* Case A: Deleted in one */
1379 if ((!a_sha && !b_sha) ||
1380 (sha_eq(a_sha, o_sha) && !b_sha) ||
1381 (!a_sha && sha_eq(b_sha, o_sha))) {
1382 /* Deleted in both or deleted in one and
1383 * unchanged in the other */
1384 if (a_sha)
1385 output(2, "Removed %s", path);
1386 /* do not touch working file if it did not exist */
1387 remove_file(1, path, !a_sha);
1388 } else {
1389 /* Deleted in one and changed in the other */
1390 clean_merge = 0;
1391 if (!a_sha) {
1392 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1393 "and modified in %s. Version %s of %s left in tree.",
1394 path, branch1,
1395 branch2, branch2, path);
1396 update_file(0, b_sha, b_mode, path);
1397 } else {
1398 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1399 "and modified in %s. Version %s of %s left in tree.",
1400 path, branch2,
1401 branch1, branch1, path);
1402 update_file(0, a_sha, a_mode, path);
1403 }
1404 }
1406 } else if ((!o_sha && a_sha && !b_sha) ||
1407 (!o_sha && !a_sha && b_sha)) {
1408 /* Case B: Added in one. */
1409 const char *add_branch;
1410 const char *other_branch;
1411 unsigned mode;
1412 const unsigned char *sha;
1413 const char *conf;
1415 if (a_sha) {
1416 add_branch = branch1;
1417 other_branch = branch2;
1418 mode = a_mode;
1419 sha = a_sha;
1420 conf = "file/directory";
1421 } else {
1422 add_branch = branch2;
1423 other_branch = branch1;
1424 mode = b_mode;
1425 sha = b_sha;
1426 conf = "directory/file";
1427 }
1428 if (path_list_has_path(¤t_directory_set, path)) {
1429 const char *new_path = unique_path(path, add_branch);
1430 clean_merge = 0;
1431 output(1, "CONFLICT (%s): There is a directory with name %s in %s. "
1432 "Added %s as %s",
1433 conf, path, other_branch, path, new_path);
1434 remove_file(0, path, 0);
1435 update_file(0, sha, mode, new_path);
1436 } else {
1437 output(2, "Added %s", path);
1438 update_file(1, sha, mode, path);
1439 }
1440 } else if (a_sha && b_sha) {
1441 /* Case C: Added in both (check for same permissions) and */
1442 /* case D: Modified in both, but differently. */
1443 const char *reason = "content";
1444 struct merge_file_info mfi;
1445 struct diff_filespec o, a, b;
1447 if (!o_sha) {
1448 reason = "add/add";
1449 o_sha = (unsigned char *)null_sha1;
1450 }
1451 output(2, "Auto-merged %s", path);
1452 o.path = a.path = b.path = (char *)path;
1453 hashcpy(o.sha1, o_sha);
1454 o.mode = o_mode;
1455 hashcpy(a.sha1, a_sha);
1456 a.mode = a_mode;
1457 hashcpy(b.sha1, b_sha);
1458 b.mode = b_mode;
1460 mfi = merge_file(&o, &a, &b,
1461 branch1, branch2);
1463 clean_merge = mfi.clean;
1464 if (mfi.clean)
1465 update_file(1, mfi.sha, mfi.mode, path);
1466 else if (S_ISGITLINK(mfi.mode))
1467 output(1, "CONFLICT (submodule): Merge conflict in %s "
1468 "- needs %s", path, sha1_to_hex(b.sha1));
1469 else {
1470 output(1, "CONFLICT (%s): Merge conflict in %s",
1471 reason, path);
1473 if (index_only)
1474 update_file(0, mfi.sha, mfi.mode, path);
1475 else
1476 update_file_flags(mfi.sha, mfi.mode, path,
1477 0 /* update_cache */, 1 /* update_working_directory */);
1478 }
1479 } else if (!o_sha && !a_sha && !b_sha) {
1480 /*
1481 * this entry was deleted altogether. a_mode == 0 means
1482 * we had that path and want to actively remove it.
1483 */
1484 remove_file(1, path, !a_mode);
1485 } else
1486 die("Fatal merge failure, shouldn't happen.");
1488 return clean_merge;
1489 }
1491 int merge_trees(struct tree *head,
1492 struct tree *merge,
1493 struct tree *common,
1494 const char *branch1,
1495 const char *branch2,
1496 struct tree **result)
1497 {
1498 int code, clean;
1500 if (subtree_merge) {
1501 merge = shift_tree_object(head, merge);
1502 common = shift_tree_object(head, common);
1503 }
1505 if (sha_eq(common->object.sha1, merge->object.sha1)) {
1506 output(0, "Already uptodate!");
1507 *result = head;
1508 return 1;
1509 }
1511 code = git_merge_trees(index_only, common, head, merge);
1513 if (code != 0)
1514 die("merging of trees %s and %s failed",
1515 sha1_to_hex(head->object.sha1),
1516 sha1_to_hex(merge->object.sha1));
1518 if (unmerged_cache()) {
1519 struct path_list *entries, *re_head, *re_merge;
1520 int i;
1521 path_list_clear(¤t_file_set, 1);
1522 path_list_clear(¤t_directory_set, 1);
1523 get_files_dirs(head);
1524 get_files_dirs(merge);
1526 entries = get_unmerged();
1527 re_head = get_renames(head, common, head, merge, entries);
1528 re_merge = get_renames(merge, common, head, merge, entries);
1529 clean = process_renames(re_head, re_merge,
1530 branch1, branch2);
1531 for (i = 0; i < entries->nr; i++) {
1532 const char *path = entries->items[i].path;
1533 struct stage_data *e = entries->items[i].util;
1534 if (!e->processed
1535 && !process_entry(path, e, branch1, branch2))
1536 clean = 0;
1537 }
1539 path_list_clear(re_merge, 0);
1540 path_list_clear(re_head, 0);
1541 path_list_clear(entries, 1);
1543 }
1544 else
1545 clean = 1;
1547 if (index_only)
1548 *result = write_tree_from_memory();
1550 return clean;
1551 }
1553 static struct commit_list *reverse_commit_list(struct commit_list *list)
1554 {
1555 struct commit_list *next = NULL, *current, *backup;
1556 for (current = list; current; current = backup) {
1557 backup = current->next;
1558 current->next = next;
1559 next = current;
1560 }
1561 return next;
1562 }
1564 /*
1565 * Merge the commits h1 and h2, return the resulting virtual
1566 * commit object and a flag indicating the cleanness of the merge.
1567 */
1568 int merge_recursive(struct commit *h1,
1569 struct commit *h2,
1570 const char *branch1,
1571 const char *branch2,
1572 struct commit_list *ca,
1573 struct commit **result)
1574 {
1575 struct commit_list *iter;
1576 struct commit *merged_common_ancestors;
1577 struct tree *mrtree = mrtree;
1578 int clean;
1580 if (show(4)) {
1581 output(4, "Merging:");
1582 output_commit_title(h1);
1583 output_commit_title(h2);
1584 }
1586 if (!ca) {
1587 ca = get_merge_bases(h1, h2, 1);
1588 ca = reverse_commit_list(ca);
1589 }
1591 if (show(5)) {
1592 output(5, "found %u common ancestor(s):", commit_list_count(ca));
1593 for (iter = ca; iter; iter = iter->next)
1594 output_commit_title(iter->item);
1595 }
1597 merged_common_ancestors = pop_commit(&ca);
1598 if (merged_common_ancestors == NULL) {
1599 /* if there is no common ancestor, make an empty tree */
1600 struct tree *tree = xcalloc(1, sizeof(struct tree));
1602 tree->object.parsed = 1;
1603 tree->object.type = OBJ_TREE;
1604 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1605 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1606 }
1608 for (iter = ca; iter; iter = iter->next) {
1609 call_depth++;
1610 /*
1611 * When the merge fails, the result contains files
1612 * with conflict markers. The cleanness flag is
1613 * ignored, it was never actually used, as result of
1614 * merge_trees has always overwritten it: the committed
1615 * "conflicts" were already resolved.
1616 */
1617 discard_cache();
1618 merge_recursive(merged_common_ancestors, iter->item,
1619 "Temporary merge branch 1",
1620 "Temporary merge branch 2",
1621 NULL,
1622 &merged_common_ancestors);
1623 call_depth--;
1625 if (!merged_common_ancestors)
1626 die("merge returned no commit");
1627 }
1629 discard_cache();
1630 if (!call_depth) {
1631 read_cache();
1632 index_only = 0;
1633 } else
1634 index_only = 1;
1636 clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
1637 branch1, branch2, &mrtree);
1639 if (index_only) {
1640 *result = make_virtual_commit(mrtree, "merged tree");
1641 commit_list_insert(h1, &(*result)->parents);
1642 commit_list_insert(h2, &(*result)->parents->next);
1643 }
1644 flush_output();
1645 return clean;
1646 }
1648 static const char *better_branch_name(const char *branch)
1649 {
1650 static char githead_env[8 + 40 + 1];
1651 char *name;
1653 if (strlen(branch) != 40)
1654 return branch;
1655 sprintf(githead_env, "GITHEAD_%s", branch);
1656 name = getenv(githead_env);
1657 return name ? name : branch;
1658 }
1660 static struct commit *get_ref(const char *ref)
1661 {
1662 unsigned char sha1[20];
1663 struct object *object;
1665 if (get_sha1(ref, sha1))
1666 die("Could not resolve ref '%s'", ref);
1667 object = deref_tag(parse_object(sha1), ref, strlen(ref));
1668 if (!object)
1669 return NULL;
1670 if (object->type == OBJ_TREE)
1671 return make_virtual_commit((struct tree*)object,
1672 better_branch_name(ref));
1673 if (object->type != OBJ_COMMIT)
1674 return NULL;
1675 if (parse_commit((struct commit *)object))
1676 die("Could not parse commit '%s'", sha1_to_hex(object->sha1));
1677 return (struct commit *)object;
1678 }
1680 static int merge_config(const char *var, const char *value)
1681 {
1682 if (!strcasecmp(var, "merge.verbosity")) {
1683 verbosity = git_config_int(var, value);
1684 return 0;
1685 }
1686 if (!strcasecmp(var, "diff.renamelimit")) {
1687 rename_limit = git_config_int(var, value);
1688 return 0;
1689 }
1690 return git_default_config(var, value);
1691 }
1693 int cmd_merge_recursive(int argc, const char **argv, const char *prefix)
1694 {
1695 static const char *bases[20];
1696 static unsigned bases_count = 0;
1697 int i, clean;
1698 const char *branch1, *branch2;
1699 struct commit *result, *h1, *h2;
1700 struct commit_list *ca = NULL;
1701 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1702 int index_fd;
1704 if (argv[0]) {
1705 int namelen = strlen(argv[0]);
1706 if (8 < namelen &&
1707 !strcmp(argv[0] + namelen - 8, "-subtree"))
1708 subtree_merge = 1;
1709 }
1711 git_config(merge_config);
1712 if (getenv("GIT_MERGE_VERBOSITY"))
1713 verbosity = strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1715 if (argc < 4)
1716 die("Usage: %s <base>... -- <head> <remote> ...\n", argv[0]);
1718 for (i = 1; i < argc; ++i) {
1719 if (!strcmp(argv[i], "--"))
1720 break;
1721 if (bases_count < sizeof(bases)/sizeof(*bases))
1722 bases[bases_count++] = argv[i];
1723 }
1724 if (argc - i != 3) /* "--" "<head>" "<remote>" */
1725 die("Not handling anything other than two heads merge.");
1726 if (verbosity >= 5)
1727 buffer_output = 0;
1729 branch1 = argv[++i];
1730 branch2 = argv[++i];
1732 h1 = get_ref(branch1);
1733 h2 = get_ref(branch2);
1735 branch1 = better_branch_name(branch1);
1736 branch2 = better_branch_name(branch2);
1738 if (show(3))
1739 printf("Merging %s with %s\n", branch1, branch2);
1741 index_fd = hold_locked_index(lock, 1);
1743 for (i = 0; i < bases_count; i++) {
1744 struct commit *ancestor = get_ref(bases[i]);
1745 ca = commit_list_insert(ancestor, &ca);
1746 }
1747 clean = merge_recursive(h1, h2, branch1, branch2, ca, &result);
1749 if (active_cache_changed &&
1750 (write_cache(index_fd, active_cache, active_nr) ||
1751 commit_locked_index(lock)))
1752 die ("unable to write %s", get_index_file());
1754 return clean ? 0: 1;
1755 }