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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;
217 init_tree_desc_from_tree(t+0, common);
218 init_tree_desc_from_tree(t+1, head);
219 init_tree_desc_from_tree(t+2, merge);
221 rc = unpack_trees(3, t, &opts);
222 cache_tree_free(&active_cache_tree);
223 return rc;
224 }
226 struct tree *write_tree_from_memory(void)
227 {
228 struct tree *result = NULL;
230 if (unmerged_cache()) {
231 int i;
232 output(0, "There are unmerged index entries:");
233 for (i = 0; i < active_nr; i++) {
234 struct cache_entry *ce = active_cache[i];
235 if (ce_stage(ce))
236 output(0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
237 }
238 return NULL;
239 }
241 if (!active_cache_tree)
242 active_cache_tree = cache_tree();
244 if (!cache_tree_fully_valid(active_cache_tree) &&
245 cache_tree_update(active_cache_tree,
246 active_cache, active_nr, 0, 0) < 0)
247 die("error building trees");
249 result = lookup_tree(active_cache_tree->sha1);
251 return result;
252 }
254 static int save_files_dirs(const unsigned char *sha1,
255 const char *base, int baselen, const char *path,
256 unsigned int mode, int stage)
257 {
258 int len = strlen(path);
259 char *newpath = xmalloc(baselen + len + 1);
260 memcpy(newpath, base, baselen);
261 memcpy(newpath + baselen, path, len);
262 newpath[baselen + len] = '\0';
264 if (S_ISDIR(mode))
265 path_list_insert(newpath, ¤t_directory_set);
266 else
267 path_list_insert(newpath, ¤t_file_set);
268 free(newpath);
270 return READ_TREE_RECURSIVE;
271 }
273 static int get_files_dirs(struct tree *tree)
274 {
275 int n;
276 if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs) != 0)
277 return 0;
278 n = current_file_set.nr + current_directory_set.nr;
279 return n;
280 }
282 /*
283 * Returns an index_entry instance which doesn't have to correspond to
284 * a real cache entry in Git's index.
285 */
286 static struct stage_data *insert_stage_data(const char *path,
287 struct tree *o, struct tree *a, struct tree *b,
288 struct path_list *entries)
289 {
290 struct path_list_item *item;
291 struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
292 get_tree_entry(o->object.sha1, path,
293 e->stages[1].sha, &e->stages[1].mode);
294 get_tree_entry(a->object.sha1, path,
295 e->stages[2].sha, &e->stages[2].mode);
296 get_tree_entry(b->object.sha1, path,
297 e->stages[3].sha, &e->stages[3].mode);
298 item = path_list_insert(path, entries);
299 item->util = e;
300 return e;
301 }
303 /*
304 * Create a dictionary mapping file names to stage_data objects. The
305 * dictionary contains one entry for every path with a non-zero stage entry.
306 */
307 static struct path_list *get_unmerged(void)
308 {
309 struct path_list *unmerged = xcalloc(1, sizeof(struct path_list));
310 int i;
312 unmerged->strdup_paths = 1;
314 for (i = 0; i < active_nr; i++) {
315 struct path_list_item *item;
316 struct stage_data *e;
317 struct cache_entry *ce = active_cache[i];
318 if (!ce_stage(ce))
319 continue;
321 item = path_list_lookup(ce->name, unmerged);
322 if (!item) {
323 item = path_list_insert(ce->name, unmerged);
324 item->util = xcalloc(1, sizeof(struct stage_data));
325 }
326 e = item->util;
327 e->stages[ce_stage(ce)].mode = ce->ce_mode;
328 hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
329 }
331 return unmerged;
332 }
334 struct rename
335 {
336 struct diff_filepair *pair;
337 struct stage_data *src_entry;
338 struct stage_data *dst_entry;
339 unsigned processed:1;
340 };
342 /*
343 * Get information of all renames which occurred between 'o_tree' and
344 * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
345 * 'b_tree') to be able to associate the correct cache entries with
346 * the rename information. 'tree' is always equal to either a_tree or b_tree.
347 */
348 static struct path_list *get_renames(struct tree *tree,
349 struct tree *o_tree,
350 struct tree *a_tree,
351 struct tree *b_tree,
352 struct path_list *entries)
353 {
354 int i;
355 struct path_list *renames;
356 struct diff_options opts;
358 renames = xcalloc(1, sizeof(struct path_list));
359 diff_setup(&opts);
360 DIFF_OPT_SET(&opts, RECURSIVE);
361 opts.detect_rename = DIFF_DETECT_RENAME;
362 opts.rename_limit = rename_limit;
363 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
364 if (diff_setup_done(&opts) < 0)
365 die("diff setup failed");
366 diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
367 diffcore_std(&opts);
368 for (i = 0; i < diff_queued_diff.nr; ++i) {
369 struct path_list_item *item;
370 struct rename *re;
371 struct diff_filepair *pair = diff_queued_diff.queue[i];
372 if (pair->status != 'R') {
373 diff_free_filepair(pair);
374 continue;
375 }
376 re = xmalloc(sizeof(*re));
377 re->processed = 0;
378 re->pair = pair;
379 item = path_list_lookup(re->pair->one->path, entries);
380 if (!item)
381 re->src_entry = insert_stage_data(re->pair->one->path,
382 o_tree, a_tree, b_tree, entries);
383 else
384 re->src_entry = item->util;
386 item = path_list_lookup(re->pair->two->path, entries);
387 if (!item)
388 re->dst_entry = insert_stage_data(re->pair->two->path,
389 o_tree, a_tree, b_tree, entries);
390 else
391 re->dst_entry = item->util;
392 item = path_list_insert(pair->one->path, renames);
393 item->util = re;
394 }
395 opts.output_format = DIFF_FORMAT_NO_OUTPUT;
396 diff_queued_diff.nr = 0;
397 diff_flush(&opts);
398 return renames;
399 }
401 static int update_stages(const char *path, struct diff_filespec *o,
402 struct diff_filespec *a, struct diff_filespec *b,
403 int clear)
404 {
405 int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
406 if (clear)
407 if (remove_file_from_cache(path))
408 return -1;
409 if (o)
410 if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
411 return -1;
412 if (a)
413 if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
414 return -1;
415 if (b)
416 if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
417 return -1;
418 return 0;
419 }
421 static int remove_path(const char *name)
422 {
423 int ret;
424 char *slash, *dirs;
426 ret = unlink(name);
427 if (ret)
428 return ret;
429 dirs = xstrdup(name);
430 while ((slash = strrchr(name, '/'))) {
431 *slash = '\0';
432 if (rmdir(name) != 0)
433 break;
434 }
435 free(dirs);
436 return ret;
437 }
439 static int remove_file(int clean, const char *path, int no_wd)
440 {
441 int update_cache = index_only || clean;
442 int update_working_directory = !index_only && !no_wd;
444 if (update_cache) {
445 if (remove_file_from_cache(path))
446 return -1;
447 }
448 if (update_working_directory) {
449 unlink(path);
450 if (errno != ENOENT || errno != EISDIR)
451 return -1;
452 remove_path(path);
453 }
454 return 0;
455 }
457 static char *unique_path(const char *path, const char *branch)
458 {
459 char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
460 int suffix = 0;
461 struct stat st;
462 char *p = newpath + strlen(path);
463 strcpy(newpath, path);
464 *(p++) = '~';
465 strcpy(p, branch);
466 for (; *p; ++p)
467 if ('/' == *p)
468 *p = '_';
469 while (path_list_has_path(¤t_file_set, newpath) ||
470 path_list_has_path(¤t_directory_set, newpath) ||
471 lstat(newpath, &st) == 0)
472 sprintf(p, "_%d", suffix++);
474 path_list_insert(newpath, ¤t_file_set);
475 return newpath;
476 }
478 static int mkdir_p(const char *path, unsigned long mode)
479 {
480 /* path points to cache entries, so xstrdup before messing with it */
481 char *buf = xstrdup(path);
482 int result = safe_create_leading_directories(buf);
483 free(buf);
484 return result;
485 }
487 static void flush_buffer(int fd, const char *buf, unsigned long size)
488 {
489 while (size > 0) {
490 long ret = write_in_full(fd, buf, size);
491 if (ret < 0) {
492 /* Ignore epipe */
493 if (errno == EPIPE)
494 break;
495 die("merge-recursive: %s", strerror(errno));
496 } else if (!ret) {
497 die("merge-recursive: disk full?");
498 }
499 size -= ret;
500 buf += ret;
501 }
502 }
504 static int make_room_for_path(const char *path)
505 {
506 int status;
507 const char *msg = "failed to create path '%s'%s";
509 status = mkdir_p(path, 0777);
510 if (status) {
511 if (status == -3) {
512 /* something else exists */
513 error(msg, path, ": perhaps a D/F conflict?");
514 return -1;
515 }
516 die(msg, path, "");
517 }
519 /* Successful unlink is good.. */
520 if (!unlink(path))
521 return 0;
522 /* .. and so is no existing file */
523 if (errno == ENOENT)
524 return 0;
525 /* .. but not some other error (who really cares what?) */
526 return error(msg, path, ": perhaps a D/F conflict?");
527 }
529 static void update_file_flags(const unsigned char *sha,
530 unsigned mode,
531 const char *path,
532 int update_cache,
533 int update_wd)
534 {
535 if (index_only)
536 update_wd = 0;
538 if (update_wd) {
539 enum object_type type;
540 void *buf;
541 unsigned long size;
543 if (S_ISGITLINK(mode))
544 die("cannot read object %s '%s': It is a submodule!",
545 sha1_to_hex(sha), path);
547 buf = read_sha1_file(sha, &type, &size);
548 if (!buf)
549 die("cannot read object %s '%s'", sha1_to_hex(sha), path);
550 if (type != OBJ_BLOB)
551 die("blob expected for %s '%s'", sha1_to_hex(sha), path);
553 if (make_room_for_path(path) < 0) {
554 update_wd = 0;
555 goto update_index;
556 }
557 if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
558 int fd;
559 if (mode & 0100)
560 mode = 0777;
561 else
562 mode = 0666;
563 fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
564 if (fd < 0)
565 die("failed to open %s: %s", path, strerror(errno));
566 flush_buffer(fd, buf, size);
567 close(fd);
568 } else if (S_ISLNK(mode)) {
569 char *lnk = xmemdupz(buf, size);
570 mkdir_p(path, 0777);
571 unlink(path);
572 symlink(lnk, path);
573 free(lnk);
574 } else
575 die("do not know what to do with %06o %s '%s'",
576 mode, sha1_to_hex(sha), path);
577 }
578 update_index:
579 if (update_cache)
580 add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
581 }
583 static void update_file(int clean,
584 const unsigned char *sha,
585 unsigned mode,
586 const char *path)
587 {
588 update_file_flags(sha, mode, path, index_only || clean, !index_only);
589 }
591 /* Low level file merging, update and removal */
593 struct merge_file_info
594 {
595 unsigned char sha[20];
596 unsigned mode;
597 unsigned clean:1,
598 merge:1;
599 };
601 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
602 {
603 unsigned long size;
604 enum object_type type;
606 if (!hashcmp(sha1, null_sha1)) {
607 mm->ptr = xstrdup("");
608 mm->size = 0;
609 return;
610 }
612 mm->ptr = read_sha1_file(sha1, &type, &size);
613 if (!mm->ptr || type != OBJ_BLOB)
614 die("unable to read blob object %s", sha1_to_hex(sha1));
615 mm->size = size;
616 }
618 /*
619 * Customizable low-level merge drivers support.
620 */
622 struct ll_merge_driver;
623 typedef int (*ll_merge_fn)(const struct ll_merge_driver *,
624 const char *path,
625 mmfile_t *orig,
626 mmfile_t *src1, const char *name1,
627 mmfile_t *src2, const char *name2,
628 mmbuffer_t *result);
630 struct ll_merge_driver {
631 const char *name;
632 const char *description;
633 ll_merge_fn fn;
634 const char *recursive;
635 struct ll_merge_driver *next;
636 char *cmdline;
637 };
639 /*
640 * Built-in low-levels
641 */
642 static int ll_binary_merge(const struct ll_merge_driver *drv_unused,
643 const char *path_unused,
644 mmfile_t *orig,
645 mmfile_t *src1, const char *name1,
646 mmfile_t *src2, const char *name2,
647 mmbuffer_t *result)
648 {
649 /*
650 * The tentative merge result is "ours" for the final round,
651 * or common ancestor for an internal merge. Still return
652 * "conflicted merge" status.
653 */
654 mmfile_t *stolen = index_only ? orig : src1;
656 result->ptr = stolen->ptr;
657 result->size = stolen->size;
658 stolen->ptr = NULL;
659 return 1;
660 }
662 static int ll_xdl_merge(const struct ll_merge_driver *drv_unused,
663 const char *path_unused,
664 mmfile_t *orig,
665 mmfile_t *src1, const char *name1,
666 mmfile_t *src2, const char *name2,
667 mmbuffer_t *result)
668 {
669 xpparam_t xpp;
671 if (buffer_is_binary(orig->ptr, orig->size) ||
672 buffer_is_binary(src1->ptr, src1->size) ||
673 buffer_is_binary(src2->ptr, src2->size)) {
674 warning("Cannot merge binary files: %s vs. %s\n",
675 name1, name2);
676 return ll_binary_merge(drv_unused, path_unused,
677 orig, src1, name1,
678 src2, name2,
679 result);
680 }
682 memset(&xpp, 0, sizeof(xpp));
683 return xdl_merge(orig,
684 src1, name1,
685 src2, name2,
686 &xpp, XDL_MERGE_ZEALOUS,
687 result);
688 }
690 static int ll_union_merge(const struct ll_merge_driver *drv_unused,
691 const char *path_unused,
692 mmfile_t *orig,
693 mmfile_t *src1, const char *name1,
694 mmfile_t *src2, const char *name2,
695 mmbuffer_t *result)
696 {
697 char *src, *dst;
698 long size;
699 const int marker_size = 7;
701 int status = ll_xdl_merge(drv_unused, path_unused,
702 orig, src1, NULL, src2, NULL, result);
703 if (status <= 0)
704 return status;
705 size = result->size;
706 src = dst = result->ptr;
707 while (size) {
708 char ch;
709 if ((marker_size < size) &&
710 (*src == '<' || *src == '=' || *src == '>')) {
711 int i;
712 ch = *src;
713 for (i = 0; i < marker_size; i++)
714 if (src[i] != ch)
715 goto not_a_marker;
716 if (src[marker_size] != '\n')
717 goto not_a_marker;
718 src += marker_size + 1;
719 size -= marker_size + 1;
720 continue;
721 }
722 not_a_marker:
723 do {
724 ch = *src++;
725 *dst++ = ch;
726 size--;
727 } while (ch != '\n' && size);
728 }
729 result->size = dst - result->ptr;
730 return 0;
731 }
733 #define LL_BINARY_MERGE 0
734 #define LL_TEXT_MERGE 1
735 #define LL_UNION_MERGE 2
736 static struct ll_merge_driver ll_merge_drv[] = {
737 { "binary", "built-in binary merge", ll_binary_merge },
738 { "text", "built-in 3-way text merge", ll_xdl_merge },
739 { "union", "built-in union merge", ll_union_merge },
740 };
742 static void create_temp(mmfile_t *src, char *path)
743 {
744 int fd;
746 strcpy(path, ".merge_file_XXXXXX");
747 fd = xmkstemp(path);
748 if (write_in_full(fd, src->ptr, src->size) != src->size)
749 die("unable to write temp-file");
750 close(fd);
751 }
753 /*
754 * User defined low-level merge driver support.
755 */
756 static int ll_ext_merge(const struct ll_merge_driver *fn,
757 const char *path,
758 mmfile_t *orig,
759 mmfile_t *src1, const char *name1,
760 mmfile_t *src2, const char *name2,
761 mmbuffer_t *result)
762 {
763 char temp[3][50];
764 char cmdbuf[2048];
765 struct interp table[] = {
766 { "%O" },
767 { "%A" },
768 { "%B" },
769 };
770 struct child_process child;
771 const char *args[20];
772 int status, fd, i;
773 struct stat st;
775 if (fn->cmdline == NULL)
776 die("custom merge driver %s lacks command line.", fn->name);
778 result->ptr = NULL;
779 result->size = 0;
780 create_temp(orig, temp[0]);
781 create_temp(src1, temp[1]);
782 create_temp(src2, temp[2]);
784 interp_set_entry(table, 0, temp[0]);
785 interp_set_entry(table, 1, temp[1]);
786 interp_set_entry(table, 2, temp[2]);
788 output(1, "merging %s using %s", path,
789 fn->description ? fn->description : fn->name);
791 interpolate(cmdbuf, sizeof(cmdbuf), fn->cmdline, table, 3);
793 memset(&child, 0, sizeof(child));
794 child.argv = args;
795 args[0] = "sh";
796 args[1] = "-c";
797 args[2] = cmdbuf;
798 args[3] = NULL;
800 status = run_command(&child);
801 if (status < -ERR_RUN_COMMAND_FORK)
802 ; /* failure in run-command */
803 else
804 status = -status;
805 fd = open(temp[1], O_RDONLY);
806 if (fd < 0)
807 goto bad;
808 if (fstat(fd, &st))
809 goto close_bad;
810 result->size = st.st_size;
811 result->ptr = xmalloc(result->size + 1);
812 if (read_in_full(fd, result->ptr, result->size) != result->size) {
813 free(result->ptr);
814 result->ptr = NULL;
815 result->size = 0;
816 }
817 close_bad:
818 close(fd);
819 bad:
820 for (i = 0; i < 3; i++)
821 unlink(temp[i]);
822 return status;
823 }
825 /*
826 * merge.default and merge.driver configuration items
827 */
828 static struct ll_merge_driver *ll_user_merge, **ll_user_merge_tail;
829 static const char *default_ll_merge;
831 static int read_merge_config(const char *var, const char *value)
832 {
833 struct ll_merge_driver *fn;
834 const char *ep, *name;
835 int namelen;
837 if (!strcmp(var, "merge.default")) {
838 if (!value)
839 return config_error_nonbool(var);
840 default_ll_merge = strdup(value);
841 return 0;
842 }
844 /*
845 * We are not interested in anything but "merge.<name>.variable";
846 * especially, we do not want to look at variables such as
847 * "merge.summary", "merge.tool", and "merge.verbosity".
848 */
849 if (prefixcmp(var, "merge.") || (ep = strrchr(var, '.')) == var + 5)
850 return 0;
852 /*
853 * Find existing one as we might be processing merge.<name>.var2
854 * after seeing merge.<name>.var1.
855 */
856 name = var + 6;
857 namelen = ep - name;
858 for (fn = ll_user_merge; fn; fn = fn->next)
859 if (!strncmp(fn->name, name, namelen) && !fn->name[namelen])
860 break;
861 if (!fn) {
862 fn = xcalloc(1, sizeof(struct ll_merge_driver));
863 fn->name = xmemdupz(name, namelen);
864 fn->fn = ll_ext_merge;
865 *ll_user_merge_tail = fn;
866 ll_user_merge_tail = &(fn->next);
867 }
869 ep++;
871 if (!strcmp("name", ep)) {
872 if (!value)
873 return config_error_nonbool(var);
874 fn->description = strdup(value);
875 return 0;
876 }
878 if (!strcmp("driver", ep)) {
879 if (!value)
880 return config_error_nonbool(var);
881 /*
882 * merge.<name>.driver specifies the command line:
883 *
884 * command-line
885 *
886 * The command-line will be interpolated with the following
887 * tokens and is given to the shell:
888 *
889 * %O - temporary file name for the merge base.
890 * %A - temporary file name for our version.
891 * %B - temporary file name for the other branches' version.
892 *
893 * The external merge driver should write the results in the
894 * file named by %A, and signal that it has done with zero exit
895 * status.
896 */
897 fn->cmdline = strdup(value);
898 return 0;
899 }
901 if (!strcmp("recursive", ep)) {
902 if (!value)
903 return config_error_nonbool(var);
904 fn->recursive = strdup(value);
905 return 0;
906 }
908 return 0;
909 }
911 static void initialize_ll_merge(void)
912 {
913 if (ll_user_merge_tail)
914 return;
915 ll_user_merge_tail = &ll_user_merge;
916 git_config(read_merge_config);
917 }
919 static const struct ll_merge_driver *find_ll_merge_driver(const char *merge_attr)
920 {
921 struct ll_merge_driver *fn;
922 const char *name;
923 int i;
925 initialize_ll_merge();
927 if (ATTR_TRUE(merge_attr))
928 return &ll_merge_drv[LL_TEXT_MERGE];
929 else if (ATTR_FALSE(merge_attr))
930 return &ll_merge_drv[LL_BINARY_MERGE];
931 else if (ATTR_UNSET(merge_attr)) {
932 if (!default_ll_merge)
933 return &ll_merge_drv[LL_TEXT_MERGE];
934 else
935 name = default_ll_merge;
936 }
937 else
938 name = merge_attr;
940 for (fn = ll_user_merge; fn; fn = fn->next)
941 if (!strcmp(fn->name, name))
942 return fn;
944 for (i = 0; i < ARRAY_SIZE(ll_merge_drv); i++)
945 if (!strcmp(ll_merge_drv[i].name, name))
946 return &ll_merge_drv[i];
948 /* default to the 3-way */
949 return &ll_merge_drv[LL_TEXT_MERGE];
950 }
952 static const char *git_path_check_merge(const char *path)
953 {
954 static struct git_attr_check attr_merge_check;
956 if (!attr_merge_check.attr)
957 attr_merge_check.attr = git_attr("merge", 5);
959 if (git_checkattr(path, 1, &attr_merge_check))
960 return NULL;
961 return attr_merge_check.value;
962 }
964 static int ll_merge(mmbuffer_t *result_buf,
965 struct diff_filespec *o,
966 struct diff_filespec *a,
967 struct diff_filespec *b,
968 const char *branch1,
969 const char *branch2)
970 {
971 mmfile_t orig, src1, src2;
972 char *name1, *name2;
973 int merge_status;
974 const char *ll_driver_name;
975 const struct ll_merge_driver *driver;
977 name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
978 name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
980 fill_mm(o->sha1, &orig);
981 fill_mm(a->sha1, &src1);
982 fill_mm(b->sha1, &src2);
984 ll_driver_name = git_path_check_merge(a->path);
985 driver = find_ll_merge_driver(ll_driver_name);
987 if (index_only && driver->recursive)
988 driver = find_ll_merge_driver(driver->recursive);
989 merge_status = driver->fn(driver, a->path,
990 &orig, &src1, name1, &src2, name2,
991 result_buf);
993 free(name1);
994 free(name2);
995 free(orig.ptr);
996 free(src1.ptr);
997 free(src2.ptr);
998 return merge_status;
999 }
1001 static struct merge_file_info merge_file(struct diff_filespec *o,
1002 struct diff_filespec *a, struct diff_filespec *b,
1003 const char *branch1, const char *branch2)
1004 {
1005 struct merge_file_info result;
1006 result.merge = 0;
1007 result.clean = 1;
1009 if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
1010 result.clean = 0;
1011 if (S_ISREG(a->mode)) {
1012 result.mode = a->mode;
1013 hashcpy(result.sha, a->sha1);
1014 } else {
1015 result.mode = b->mode;
1016 hashcpy(result.sha, b->sha1);
1017 }
1018 } else {
1019 if (!sha_eq(a->sha1, o->sha1) && !sha_eq(b->sha1, o->sha1))
1020 result.merge = 1;
1022 result.mode = a->mode == o->mode ? b->mode: a->mode;
1024 if (sha_eq(a->sha1, o->sha1))
1025 hashcpy(result.sha, b->sha1);
1026 else if (sha_eq(b->sha1, o->sha1))
1027 hashcpy(result.sha, a->sha1);
1028 else if (S_ISREG(a->mode)) {
1029 mmbuffer_t result_buf;
1030 int merge_status;
1032 merge_status = ll_merge(&result_buf, o, a, b,
1033 branch1, branch2);
1035 if ((merge_status < 0) || !result_buf.ptr)
1036 die("Failed to execute internal merge");
1038 if (write_sha1_file(result_buf.ptr, result_buf.size,
1039 blob_type, result.sha))
1040 die("Unable to add %s to database",
1041 a->path);
1043 free(result_buf.ptr);
1044 result.clean = (merge_status == 0);
1045 } else if (S_ISGITLINK(a->mode)) {
1046 result.clean = 0;
1047 hashcpy(result.sha, a->sha1);
1048 } else if (S_ISLNK(a->mode)) {
1049 hashcpy(result.sha, a->sha1);
1051 if (!sha_eq(a->sha1, b->sha1))
1052 result.clean = 0;
1053 } else {
1054 die("unsupported object type in the tree");
1055 }
1056 }
1058 return result;
1059 }
1061 static void conflict_rename_rename(struct rename *ren1,
1062 const char *branch1,
1063 struct rename *ren2,
1064 const char *branch2)
1065 {
1066 char *del[2];
1067 int delp = 0;
1068 const char *ren1_dst = ren1->pair->two->path;
1069 const char *ren2_dst = ren2->pair->two->path;
1070 const char *dst_name1 = ren1_dst;
1071 const char *dst_name2 = ren2_dst;
1072 if (path_list_has_path(¤t_directory_set, ren1_dst)) {
1073 dst_name1 = del[delp++] = unique_path(ren1_dst, branch1);
1074 output(1, "%s is a directory in %s added as %s instead",
1075 ren1_dst, branch2, dst_name1);
1076 remove_file(0, ren1_dst, 0);
1077 }
1078 if (path_list_has_path(¤t_directory_set, ren2_dst)) {
1079 dst_name2 = del[delp++] = unique_path(ren2_dst, branch2);
1080 output(1, "%s is a directory in %s added as %s instead",
1081 ren2_dst, branch1, dst_name2);
1082 remove_file(0, ren2_dst, 0);
1083 }
1084 if (index_only) {
1085 remove_file_from_cache(dst_name1);
1086 remove_file_from_cache(dst_name2);
1087 /*
1088 * Uncomment to leave the conflicting names in the resulting tree
1089 *
1090 * update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
1091 * update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
1092 */
1093 } else {
1094 update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
1095 update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
1096 }
1097 while (delp--)
1098 free(del[delp]);
1099 }
1101 static void conflict_rename_dir(struct rename *ren1,
1102 const char *branch1)
1103 {
1104 char *new_path = unique_path(ren1->pair->two->path, branch1);
1105 output(1, "Renamed %s to %s instead", ren1->pair->one->path, new_path);
1106 remove_file(0, ren1->pair->two->path, 0);
1107 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
1108 free(new_path);
1109 }
1111 static void conflict_rename_rename_2(struct rename *ren1,
1112 const char *branch1,
1113 struct rename *ren2,
1114 const char *branch2)
1115 {
1116 char *new_path1 = unique_path(ren1->pair->two->path, branch1);
1117 char *new_path2 = unique_path(ren2->pair->two->path, branch2);
1118 output(1, "Renamed %s to %s and %s to %s instead",
1119 ren1->pair->one->path, new_path1,
1120 ren2->pair->one->path, new_path2);
1121 remove_file(0, ren1->pair->two->path, 0);
1122 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
1123 update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
1124 free(new_path2);
1125 free(new_path1);
1126 }
1128 static int process_renames(struct path_list *a_renames,
1129 struct path_list *b_renames,
1130 const char *a_branch,
1131 const char *b_branch)
1132 {
1133 int clean_merge = 1, i, j;
1134 struct path_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
1135 const struct rename *sre;
1137 for (i = 0; i < a_renames->nr; i++) {
1138 sre = a_renames->items[i].util;
1139 path_list_insert(sre->pair->two->path, &a_by_dst)->util
1140 = sre->dst_entry;
1141 }
1142 for (i = 0; i < b_renames->nr; i++) {
1143 sre = b_renames->items[i].util;
1144 path_list_insert(sre->pair->two->path, &b_by_dst)->util
1145 = sre->dst_entry;
1146 }
1148 for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
1149 int compare;
1150 char *src;
1151 struct path_list *renames1, *renames2, *renames2Dst;
1152 struct rename *ren1 = NULL, *ren2 = NULL;
1153 const char *branch1, *branch2;
1154 const char *ren1_src, *ren1_dst;
1156 if (i >= a_renames->nr) {
1157 compare = 1;
1158 ren2 = b_renames->items[j++].util;
1159 } else if (j >= b_renames->nr) {
1160 compare = -1;
1161 ren1 = a_renames->items[i++].util;
1162 } else {
1163 compare = strcmp(a_renames->items[i].path,
1164 b_renames->items[j].path);
1165 if (compare <= 0)
1166 ren1 = a_renames->items[i++].util;
1167 if (compare >= 0)
1168 ren2 = b_renames->items[j++].util;
1169 }
1171 /* TODO: refactor, so that 1/2 are not needed */
1172 if (ren1) {
1173 renames1 = a_renames;
1174 renames2 = b_renames;
1175 renames2Dst = &b_by_dst;
1176 branch1 = a_branch;
1177 branch2 = b_branch;
1178 } else {
1179 struct rename *tmp;
1180 renames1 = b_renames;
1181 renames2 = a_renames;
1182 renames2Dst = &a_by_dst;
1183 branch1 = b_branch;
1184 branch2 = a_branch;
1185 tmp = ren2;
1186 ren2 = ren1;
1187 ren1 = tmp;
1188 }
1189 src = ren1->pair->one->path;
1191 ren1->dst_entry->processed = 1;
1192 ren1->src_entry->processed = 1;
1194 if (ren1->processed)
1195 continue;
1196 ren1->processed = 1;
1198 ren1_src = ren1->pair->one->path;
1199 ren1_dst = ren1->pair->two->path;
1201 if (ren2) {
1202 const char *ren2_src = ren2->pair->one->path;
1203 const char *ren2_dst = ren2->pair->two->path;
1204 /* Renamed in 1 and renamed in 2 */
1205 if (strcmp(ren1_src, ren2_src) != 0)
1206 die("ren1.src != ren2.src");
1207 ren2->dst_entry->processed = 1;
1208 ren2->processed = 1;
1209 if (strcmp(ren1_dst, ren2_dst) != 0) {
1210 clean_merge = 0;
1211 output(1, "CONFLICT (rename/rename): "
1212 "Rename \"%s\"->\"%s\" in branch \"%s\" "
1213 "rename \"%s\"->\"%s\" in \"%s\"%s",
1214 src, ren1_dst, branch1,
1215 src, ren2_dst, branch2,
1216 index_only ? " (left unresolved)": "");
1217 if (index_only) {
1218 remove_file_from_cache(src);
1219 update_file(0, ren1->pair->one->sha1,
1220 ren1->pair->one->mode, src);
1221 }
1222 conflict_rename_rename(ren1, branch1, ren2, branch2);
1223 } else {
1224 struct merge_file_info mfi;
1225 remove_file(1, ren1_src, 1);
1226 mfi = merge_file(ren1->pair->one,
1227 ren1->pair->two,
1228 ren2->pair->two,
1229 branch1,
1230 branch2);
1231 if (mfi.merge || !mfi.clean)
1232 output(1, "Renamed %s->%s", src, ren1_dst);
1234 if (mfi.merge)
1235 output(2, "Auto-merged %s", ren1_dst);
1237 if (!mfi.clean) {
1238 output(1, "CONFLICT (content): merge conflict in %s",
1239 ren1_dst);
1240 clean_merge = 0;
1242 if (!index_only)
1243 update_stages(ren1_dst,
1244 ren1->pair->one,
1245 ren1->pair->two,
1246 ren2->pair->two,
1247 1 /* clear */);
1248 }
1249 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1250 }
1251 } else {
1252 /* Renamed in 1, maybe changed in 2 */
1253 struct path_list_item *item;
1254 /* we only use sha1 and mode of these */
1255 struct diff_filespec src_other, dst_other;
1256 int try_merge, stage = a_renames == renames1 ? 3: 2;
1258 remove_file(1, ren1_src, index_only || stage == 3);
1260 hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
1261 src_other.mode = ren1->src_entry->stages[stage].mode;
1262 hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
1263 dst_other.mode = ren1->dst_entry->stages[stage].mode;
1265 try_merge = 0;
1267 if (path_list_has_path(¤t_directory_set, ren1_dst)) {
1268 clean_merge = 0;
1269 output(1, "CONFLICT (rename/directory): Renamed %s->%s in %s "
1270 " directory %s added in %s",
1271 ren1_src, ren1_dst, branch1,
1272 ren1_dst, branch2);
1273 conflict_rename_dir(ren1, branch1);
1274 } else if (sha_eq(src_other.sha1, null_sha1)) {
1275 clean_merge = 0;
1276 output(1, "CONFLICT (rename/delete): Renamed %s->%s in %s "
1277 "and deleted in %s",
1278 ren1_src, ren1_dst, branch1,
1279 branch2);
1280 update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
1281 } else if (!sha_eq(dst_other.sha1, null_sha1)) {
1282 const char *new_path;
1283 clean_merge = 0;
1284 try_merge = 1;
1285 output(1, "CONFLICT (rename/add): Renamed %s->%s in %s. "
1286 "%s added in %s",
1287 ren1_src, ren1_dst, branch1,
1288 ren1_dst, branch2);
1289 new_path = unique_path(ren1_dst, branch2);
1290 output(1, "Added as %s instead", new_path);
1291 update_file(0, dst_other.sha1, dst_other.mode, new_path);
1292 } else if ((item = path_list_lookup(ren1_dst, renames2Dst))) {
1293 ren2 = item->util;
1294 clean_merge = 0;
1295 ren2->processed = 1;
1296 output(1, "CONFLICT (rename/rename): Renamed %s->%s in %s. "
1297 "Renamed %s->%s in %s",
1298 ren1_src, ren1_dst, branch1,
1299 ren2->pair->one->path, ren2->pair->two->path, branch2);
1300 conflict_rename_rename_2(ren1, branch1, ren2, branch2);
1301 } else
1302 try_merge = 1;
1304 if (try_merge) {
1305 struct diff_filespec *o, *a, *b;
1306 struct merge_file_info mfi;
1307 src_other.path = (char *)ren1_src;
1309 o = ren1->pair->one;
1310 if (a_renames == renames1) {
1311 a = ren1->pair->two;
1312 b = &src_other;
1313 } else {
1314 b = ren1->pair->two;
1315 a = &src_other;
1316 }
1317 mfi = merge_file(o, a, b,
1318 a_branch, b_branch);
1320 if (mfi.clean &&
1321 sha_eq(mfi.sha, ren1->pair->two->sha1) &&
1322 mfi.mode == ren1->pair->two->mode)
1323 /*
1324 * This messaged is part of
1325 * t6022 test. If you change
1326 * it update the test too.
1327 */
1328 output(3, "Skipped %s (merged same as existing)", ren1_dst);
1329 else {
1330 if (mfi.merge || !mfi.clean)
1331 output(1, "Renamed %s => %s", ren1_src, ren1_dst);
1332 if (mfi.merge)
1333 output(2, "Auto-merged %s", ren1_dst);
1334 if (!mfi.clean) {
1335 output(1, "CONFLICT (rename/modify): Merge conflict in %s",
1336 ren1_dst);
1337 clean_merge = 0;
1339 if (!index_only)
1340 update_stages(ren1_dst,
1341 o, a, b, 1);
1342 }
1343 update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
1344 }
1345 }
1346 }
1347 }
1348 path_list_clear(&a_by_dst, 0);
1349 path_list_clear(&b_by_dst, 0);
1351 return clean_merge;
1352 }
1354 static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
1355 {
1356 return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
1357 }
1359 /* Per entry merge function */
1360 static int process_entry(const char *path, struct stage_data *entry,
1361 const char *branch1,
1362 const char *branch2)
1363 {
1364 /*
1365 printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
1366 print_index_entry("\tpath: ", entry);
1367 */
1368 int clean_merge = 1;
1369 unsigned o_mode = entry->stages[1].mode;
1370 unsigned a_mode = entry->stages[2].mode;
1371 unsigned b_mode = entry->stages[3].mode;
1372 unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
1373 unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
1374 unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
1376 if (o_sha && (!a_sha || !b_sha)) {
1377 /* Case A: Deleted in one */
1378 if ((!a_sha && !b_sha) ||
1379 (sha_eq(a_sha, o_sha) && !b_sha) ||
1380 (!a_sha && sha_eq(b_sha, o_sha))) {
1381 /* Deleted in both or deleted in one and
1382 * unchanged in the other */
1383 if (a_sha)
1384 output(2, "Removed %s", path);
1385 /* do not touch working file if it did not exist */
1386 remove_file(1, path, !a_sha);
1387 } else {
1388 /* Deleted in one and changed in the other */
1389 clean_merge = 0;
1390 if (!a_sha) {
1391 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1392 "and modified in %s. Version %s of %s left in tree.",
1393 path, branch1,
1394 branch2, branch2, path);
1395 update_file(0, b_sha, b_mode, path);
1396 } else {
1397 output(1, "CONFLICT (delete/modify): %s deleted in %s "
1398 "and modified in %s. Version %s of %s left in tree.",
1399 path, branch2,
1400 branch1, branch1, path);
1401 update_file(0, a_sha, a_mode, path);
1402 }
1403 }
1405 } else if ((!o_sha && a_sha && !b_sha) ||
1406 (!o_sha && !a_sha && b_sha)) {
1407 /* Case B: Added in one. */
1408 const char *add_branch;
1409 const char *other_branch;
1410 unsigned mode;
1411 const unsigned char *sha;
1412 const char *conf;
1414 if (a_sha) {
1415 add_branch = branch1;
1416 other_branch = branch2;
1417 mode = a_mode;
1418 sha = a_sha;
1419 conf = "file/directory";
1420 } else {
1421 add_branch = branch2;
1422 other_branch = branch1;
1423 mode = b_mode;
1424 sha = b_sha;
1425 conf = "directory/file";
1426 }
1427 if (path_list_has_path(¤t_directory_set, path)) {
1428 const char *new_path = unique_path(path, add_branch);
1429 clean_merge = 0;
1430 output(1, "CONFLICT (%s): There is a directory with name %s in %s. "
1431 "Added %s as %s",
1432 conf, path, other_branch, path, new_path);
1433 remove_file(0, path, 0);
1434 update_file(0, sha, mode, new_path);
1435 } else {
1436 output(2, "Added %s", path);
1437 update_file(1, sha, mode, path);
1438 }
1439 } else if (a_sha && b_sha) {
1440 /* Case C: Added in both (check for same permissions) and */
1441 /* case D: Modified in both, but differently. */
1442 const char *reason = "content";
1443 struct merge_file_info mfi;
1444 struct diff_filespec o, a, b;
1446 if (!o_sha) {
1447 reason = "add/add";
1448 o_sha = (unsigned char *)null_sha1;
1449 }
1450 output(2, "Auto-merged %s", path);
1451 o.path = a.path = b.path = (char *)path;
1452 hashcpy(o.sha1, o_sha);
1453 o.mode = o_mode;
1454 hashcpy(a.sha1, a_sha);
1455 a.mode = a_mode;
1456 hashcpy(b.sha1, b_sha);
1457 b.mode = b_mode;
1459 mfi = merge_file(&o, &a, &b,
1460 branch1, branch2);
1462 clean_merge = mfi.clean;
1463 if (mfi.clean)
1464 update_file(1, mfi.sha, mfi.mode, path);
1465 else if (S_ISGITLINK(mfi.mode))
1466 output(1, "CONFLICT (submodule): Merge conflict in %s "
1467 "- needs %s", path, sha1_to_hex(b.sha1));
1468 else {
1469 output(1, "CONFLICT (%s): Merge conflict in %s",
1470 reason, path);
1472 if (index_only)
1473 update_file(0, mfi.sha, mfi.mode, path);
1474 else
1475 update_file_flags(mfi.sha, mfi.mode, path,
1476 0 /* update_cache */, 1 /* update_working_directory */);
1477 }
1478 } else if (!o_sha && !a_sha && !b_sha) {
1479 /*
1480 * this entry was deleted altogether. a_mode == 0 means
1481 * we had that path and want to actively remove it.
1482 */
1483 remove_file(1, path, !a_mode);
1484 } else
1485 die("Fatal merge failure, shouldn't happen.");
1487 return clean_merge;
1488 }
1490 int merge_trees(struct tree *head,
1491 struct tree *merge,
1492 struct tree *common,
1493 const char *branch1,
1494 const char *branch2,
1495 struct tree **result)
1496 {
1497 int code, clean;
1499 if (subtree_merge) {
1500 merge = shift_tree_object(head, merge);
1501 common = shift_tree_object(head, common);
1502 }
1504 if (sha_eq(common->object.sha1, merge->object.sha1)) {
1505 output(0, "Already uptodate!");
1506 *result = head;
1507 return 1;
1508 }
1510 code = git_merge_trees(index_only, common, head, merge);
1512 if (code != 0)
1513 die("merging of trees %s and %s failed",
1514 sha1_to_hex(head->object.sha1),
1515 sha1_to_hex(merge->object.sha1));
1517 if (unmerged_cache()) {
1518 struct path_list *entries, *re_head, *re_merge;
1519 int i;
1520 path_list_clear(¤t_file_set, 1);
1521 path_list_clear(¤t_directory_set, 1);
1522 get_files_dirs(head);
1523 get_files_dirs(merge);
1525 entries = get_unmerged();
1526 re_head = get_renames(head, common, head, merge, entries);
1527 re_merge = get_renames(merge, common, head, merge, entries);
1528 clean = process_renames(re_head, re_merge,
1529 branch1, branch2);
1530 for (i = 0; i < entries->nr; i++) {
1531 const char *path = entries->items[i].path;
1532 struct stage_data *e = entries->items[i].util;
1533 if (!e->processed
1534 && !process_entry(path, e, branch1, branch2))
1535 clean = 0;
1536 }
1538 path_list_clear(re_merge, 0);
1539 path_list_clear(re_head, 0);
1540 path_list_clear(entries, 1);
1542 }
1543 else
1544 clean = 1;
1546 if (index_only)
1547 *result = write_tree_from_memory();
1549 return clean;
1550 }
1552 static struct commit_list *reverse_commit_list(struct commit_list *list)
1553 {
1554 struct commit_list *next = NULL, *current, *backup;
1555 for (current = list; current; current = backup) {
1556 backup = current->next;
1557 current->next = next;
1558 next = current;
1559 }
1560 return next;
1561 }
1563 /*
1564 * Merge the commits h1 and h2, return the resulting virtual
1565 * commit object and a flag indicating the cleanness of the merge.
1566 */
1567 int merge_recursive(struct commit *h1,
1568 struct commit *h2,
1569 const char *branch1,
1570 const char *branch2,
1571 struct commit_list *ca,
1572 struct commit **result)
1573 {
1574 struct commit_list *iter;
1575 struct commit *merged_common_ancestors;
1576 struct tree *mrtree = mrtree;
1577 int clean;
1579 if (show(4)) {
1580 output(4, "Merging:");
1581 output_commit_title(h1);
1582 output_commit_title(h2);
1583 }
1585 if (!ca) {
1586 ca = get_merge_bases(h1, h2, 1);
1587 ca = reverse_commit_list(ca);
1588 }
1590 if (show(5)) {
1591 output(5, "found %u common ancestor(s):", commit_list_count(ca));
1592 for (iter = ca; iter; iter = iter->next)
1593 output_commit_title(iter->item);
1594 }
1596 merged_common_ancestors = pop_commit(&ca);
1597 if (merged_common_ancestors == NULL) {
1598 /* if there is no common ancestor, make an empty tree */
1599 struct tree *tree = xcalloc(1, sizeof(struct tree));
1601 tree->object.parsed = 1;
1602 tree->object.type = OBJ_TREE;
1603 pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
1604 merged_common_ancestors = make_virtual_commit(tree, "ancestor");
1605 }
1607 for (iter = ca; iter; iter = iter->next) {
1608 call_depth++;
1609 /*
1610 * When the merge fails, the result contains files
1611 * with conflict markers. The cleanness flag is
1612 * ignored, it was never actually used, as result of
1613 * merge_trees has always overwritten it: the committed
1614 * "conflicts" were already resolved.
1615 */
1616 discard_cache();
1617 merge_recursive(merged_common_ancestors, iter->item,
1618 "Temporary merge branch 1",
1619 "Temporary merge branch 2",
1620 NULL,
1621 &merged_common_ancestors);
1622 call_depth--;
1624 if (!merged_common_ancestors)
1625 die("merge returned no commit");
1626 }
1628 discard_cache();
1629 if (!call_depth) {
1630 read_cache();
1631 index_only = 0;
1632 } else
1633 index_only = 1;
1635 clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
1636 branch1, branch2, &mrtree);
1638 if (index_only) {
1639 *result = make_virtual_commit(mrtree, "merged tree");
1640 commit_list_insert(h1, &(*result)->parents);
1641 commit_list_insert(h2, &(*result)->parents->next);
1642 }
1643 flush_output();
1644 return clean;
1645 }
1647 static const char *better_branch_name(const char *branch)
1648 {
1649 static char githead_env[8 + 40 + 1];
1650 char *name;
1652 if (strlen(branch) != 40)
1653 return branch;
1654 sprintf(githead_env, "GITHEAD_%s", branch);
1655 name = getenv(githead_env);
1656 return name ? name : branch;
1657 }
1659 static struct commit *get_ref(const char *ref)
1660 {
1661 unsigned char sha1[20];
1662 struct object *object;
1664 if (get_sha1(ref, sha1))
1665 die("Could not resolve ref '%s'", ref);
1666 object = deref_tag(parse_object(sha1), ref, strlen(ref));
1667 if (!object)
1668 return NULL;
1669 if (object->type == OBJ_TREE)
1670 return make_virtual_commit((struct tree*)object,
1671 better_branch_name(ref));
1672 if (object->type != OBJ_COMMIT)
1673 return NULL;
1674 if (parse_commit((struct commit *)object))
1675 die("Could not parse commit '%s'", sha1_to_hex(object->sha1));
1676 return (struct commit *)object;
1677 }
1679 static int merge_config(const char *var, const char *value)
1680 {
1681 if (!strcasecmp(var, "merge.verbosity")) {
1682 verbosity = git_config_int(var, value);
1683 return 0;
1684 }
1685 if (!strcasecmp(var, "diff.renamelimit")) {
1686 rename_limit = git_config_int(var, value);
1687 return 0;
1688 }
1689 return git_default_config(var, value);
1690 }
1692 int cmd_merge_recursive(int argc, const char **argv, const char *prefix)
1693 {
1694 static const char *bases[20];
1695 static unsigned bases_count = 0;
1696 int i, clean;
1697 const char *branch1, *branch2;
1698 struct commit *result, *h1, *h2;
1699 struct commit_list *ca = NULL;
1700 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
1701 int index_fd;
1703 if (argv[0]) {
1704 int namelen = strlen(argv[0]);
1705 if (8 < namelen &&
1706 !strcmp(argv[0] + namelen - 8, "-subtree"))
1707 subtree_merge = 1;
1708 }
1710 git_config(merge_config);
1711 if (getenv("GIT_MERGE_VERBOSITY"))
1712 verbosity = strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
1714 if (argc < 4)
1715 die("Usage: %s <base>... -- <head> <remote> ...\n", argv[0]);
1717 for (i = 1; i < argc; ++i) {
1718 if (!strcmp(argv[i], "--"))
1719 break;
1720 if (bases_count < sizeof(bases)/sizeof(*bases))
1721 bases[bases_count++] = argv[i];
1722 }
1723 if (argc - i != 3) /* "--" "<head>" "<remote>" */
1724 die("Not handling anything other than two heads merge.");
1725 if (verbosity >= 5)
1726 buffer_output = 0;
1728 branch1 = argv[++i];
1729 branch2 = argv[++i];
1731 h1 = get_ref(branch1);
1732 h2 = get_ref(branch2);
1734 branch1 = better_branch_name(branch1);
1735 branch2 = better_branch_name(branch2);
1737 if (show(3))
1738 printf("Merging %s with %s\n", branch1, branch2);
1740 index_fd = hold_locked_index(lock, 1);
1742 for (i = 0; i < bases_count; i++) {
1743 struct commit *ancestor = get_ref(bases[i]);
1744 ca = commit_list_insert(ancestor, &ca);
1745 }
1746 clean = merge_recursive(h1, h2, branch1, branch2, ca, &result);
1748 if (active_cache_changed &&
1749 (write_cache(index_fd, active_cache, active_nr) ||
1750 commit_locked_index(lock)))
1751 die ("unable to write %s", get_index_file());
1753 return clean ? 0: 1;
1754 }