Make the MSVC projects use PDB/IDB files named after the project
[git/dscho.git] / builtin-merge.c
blobb6b84286b26a4317dfd5185ae83fd861c6f9fa7d
1 /*
2 * Builtin "git merge"
4 * Copyright (c) 2008 Miklos Vajna <vmiklos@frugalware.org>
6 * Based on git-merge.sh by Junio C Hamano.
7 */
9 #include "cache.h"
10 #include "parse-options.h"
11 #include "builtin.h"
12 #include "run-command.h"
13 #include "diff.h"
14 #include "refs.h"
15 #include "commit.h"
16 #include "diffcore.h"
17 #include "revision.h"
18 #include "unpack-trees.h"
19 #include "cache-tree.h"
20 #include "dir.h"
21 #include "utf8.h"
22 #include "log-tree.h"
23 #include "color.h"
24 #include "rerere.h"
25 #include "help.h"
26 #include "merge-recursive.h"
28 #define DEFAULT_TWOHEAD (1<<0)
29 #define DEFAULT_OCTOPUS (1<<1)
30 #define NO_FAST_FORWARD (1<<2)
31 #define NO_TRIVIAL (1<<3)
33 struct strategy {
34 const char *name;
35 unsigned attr;
38 static const char * const builtin_merge_usage[] = {
39 "git merge [options] <remote>...",
40 "git merge [options] <msg> HEAD <remote>",
41 NULL
44 static int show_diffstat = 1, option_log, squash;
45 static int option_commit = 1, allow_fast_forward = 1;
46 static int allow_trivial = 1, have_message;
47 static struct strbuf merge_msg;
48 static struct commit_list *remoteheads;
49 static unsigned char head[20], stash[20];
50 static struct strategy **use_strategies;
51 static size_t use_strategies_nr, use_strategies_alloc;
52 static const char *branch;
53 static int verbosity;
55 static struct strategy all_strategy[] = {
56 { "recursive", DEFAULT_TWOHEAD | NO_TRIVIAL },
57 { "octopus", DEFAULT_OCTOPUS },
58 { "resolve", 0 },
59 { "ours", NO_FAST_FORWARD | NO_TRIVIAL },
60 { "subtree", NO_FAST_FORWARD | NO_TRIVIAL },
63 static const char *pull_twohead, *pull_octopus;
65 static int option_parse_message(const struct option *opt,
66 const char *arg, int unset)
68 struct strbuf *buf = opt->value;
70 if (unset)
71 strbuf_setlen(buf, 0);
72 else if (arg) {
73 strbuf_addf(buf, "%s\n\n", arg);
74 have_message = 1;
75 } else
76 return error("switch `m' requires a value");
77 return 0;
80 static struct strategy *get_strategy(const char *name)
82 int i;
83 struct strategy *ret;
84 static struct cmdnames main_cmds, other_cmds;
85 static int loaded;
87 if (!name)
88 return NULL;
90 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
91 if (!strcmp(name, all_strategy[i].name))
92 return &all_strategy[i];
94 if (!loaded) {
95 struct cmdnames not_strategies;
96 loaded = 1;
98 memset(&not_strategies, 0, sizeof(struct cmdnames));
99 load_command_list("git-merge-", &main_cmds, &other_cmds);
100 for (i = 0; i < main_cmds.cnt; i++) {
101 int j, found = 0;
102 struct cmdname *ent = main_cmds.names[i];
103 for (j = 0; j < ARRAY_SIZE(all_strategy); j++)
104 if (!strncmp(ent->name, all_strategy[j].name, ent->len)
105 && !all_strategy[j].name[ent->len])
106 found = 1;
107 if (!found)
108 add_cmdname(&not_strategies, ent->name, ent->len);
109 exclude_cmds(&main_cmds, &not_strategies);
112 if (!is_in_cmdlist(&main_cmds, name) && !is_in_cmdlist(&other_cmds, name)) {
113 fprintf(stderr, "Could not find merge strategy '%s'.\n", name);
114 fprintf(stderr, "Available strategies are:");
115 for (i = 0; i < main_cmds.cnt; i++)
116 fprintf(stderr, " %s", main_cmds.names[i]->name);
117 fprintf(stderr, ".\n");
118 if (other_cmds.cnt) {
119 fprintf(stderr, "Available custom strategies are:");
120 for (i = 0; i < other_cmds.cnt; i++)
121 fprintf(stderr, " %s", other_cmds.names[i]->name);
122 fprintf(stderr, ".\n");
124 exit(1);
127 ret = xcalloc(1, sizeof(struct strategy));
128 ret->name = xstrdup(name);
129 return ret;
132 static void append_strategy(struct strategy *s)
134 ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
135 use_strategies[use_strategies_nr++] = s;
138 static int option_parse_strategy(const struct option *opt,
139 const char *name, int unset)
141 if (unset)
142 return 0;
144 append_strategy(get_strategy(name));
145 return 0;
148 static int option_parse_n(const struct option *opt,
149 const char *arg, int unset)
151 show_diffstat = unset;
152 return 0;
155 static struct option builtin_merge_options[] = {
156 { OPTION_CALLBACK, 'n', NULL, NULL, NULL,
157 "do not show a diffstat at the end of the merge",
158 PARSE_OPT_NOARG, option_parse_n },
159 OPT_BOOLEAN(0, "stat", &show_diffstat,
160 "show a diffstat at the end of the merge"),
161 OPT_BOOLEAN(0, "summary", &show_diffstat, "(synonym to --stat)"),
162 OPT_BOOLEAN(0, "log", &option_log,
163 "add list of one-line log to merge commit message"),
164 OPT_BOOLEAN(0, "squash", &squash,
165 "create a single commit instead of doing a merge"),
166 OPT_BOOLEAN(0, "commit", &option_commit,
167 "perform a commit if the merge succeeds (default)"),
168 OPT_BOOLEAN(0, "ff", &allow_fast_forward,
169 "allow fast forward (default)"),
170 OPT_CALLBACK('s', "strategy", &use_strategies, "strategy",
171 "merge strategy to use", option_parse_strategy),
172 OPT_CALLBACK('m', "message", &merge_msg, "message",
173 "message to be used for the merge commit (if any)",
174 option_parse_message),
175 OPT__VERBOSITY(&verbosity),
176 OPT_END()
179 /* Cleans up metadata that is uninteresting after a succeeded merge. */
180 static void drop_save(void)
182 unlink(git_path("MERGE_HEAD"));
183 unlink(git_path("MERGE_MSG"));
184 unlink(git_path("MERGE_MODE"));
187 static void save_state(void)
189 int len;
190 struct child_process cp;
191 struct strbuf buffer = STRBUF_INIT;
192 const char *argv[] = {"stash", "create", NULL};
194 memset(&cp, 0, sizeof(cp));
195 cp.argv = argv;
196 cp.out = -1;
197 cp.git_cmd = 1;
199 if (start_command(&cp))
200 die("could not run stash.");
201 len = strbuf_read(&buffer, cp.out, 1024);
202 close(cp.out);
204 if (finish_command(&cp) || len < 0)
205 die("stash failed");
206 else if (!len)
207 return;
208 strbuf_setlen(&buffer, buffer.len-1);
209 if (get_sha1(buffer.buf, stash))
210 die("not a valid object: %s", buffer.buf);
213 static void reset_hard(unsigned const char *sha1, int verbose)
215 int i = 0;
216 const char *args[6];
218 args[i++] = "read-tree";
219 if (verbose)
220 args[i++] = "-v";
221 args[i++] = "--reset";
222 args[i++] = "-u";
223 args[i++] = sha1_to_hex(sha1);
224 args[i] = NULL;
226 if (run_command_v_opt(args, RUN_GIT_CMD))
227 die("read-tree failed");
230 static void restore_state(void)
232 struct strbuf sb = STRBUF_INIT;
233 const char *args[] = { "stash", "apply", NULL, NULL };
235 if (is_null_sha1(stash))
236 return;
238 reset_hard(head, 1);
240 args[2] = sha1_to_hex(stash);
243 * It is OK to ignore error here, for example when there was
244 * nothing to restore.
246 run_command_v_opt(args, RUN_GIT_CMD);
248 strbuf_release(&sb);
249 refresh_cache(REFRESH_QUIET);
252 /* This is called when no merge was necessary. */
253 static void finish_up_to_date(const char *msg)
255 if (verbosity >= 0)
256 printf("%s%s\n", squash ? " (nothing to squash)" : "", msg);
257 drop_save();
260 static void squash_message(void)
262 struct rev_info rev;
263 struct commit *commit;
264 struct strbuf out = STRBUF_INIT;
265 struct commit_list *j;
266 int fd;
268 printf("Squash commit -- not updating HEAD\n");
269 fd = open(git_path("SQUASH_MSG"), O_WRONLY | O_CREAT, 0666);
270 if (fd < 0)
271 die_errno("Could not write to '%s'", git_path("SQUASH_MSG"));
273 init_revisions(&rev, NULL);
274 rev.ignore_merges = 1;
275 rev.commit_format = CMIT_FMT_MEDIUM;
277 commit = lookup_commit(head);
278 commit->object.flags |= UNINTERESTING;
279 add_pending_object(&rev, &commit->object, NULL);
281 for (j = remoteheads; j; j = j->next)
282 add_pending_object(&rev, &j->item->object, NULL);
284 setup_revisions(0, NULL, &rev, NULL);
285 if (prepare_revision_walk(&rev))
286 die("revision walk setup failed");
288 strbuf_addstr(&out, "Squashed commit of the following:\n");
289 while ((commit = get_revision(&rev)) != NULL) {
290 strbuf_addch(&out, '\n');
291 strbuf_addf(&out, "commit %s\n",
292 sha1_to_hex(commit->object.sha1));
293 pretty_print_commit(rev.commit_format, commit, &out, rev.abbrev,
294 NULL, NULL, rev.date_mode, 0);
296 if (write(fd, out.buf, out.len) < 0)
297 die_errno("Writing SQUASH_MSG");
298 if (close(fd))
299 die_errno("Finishing SQUASH_MSG");
300 strbuf_release(&out);
303 static void finish(const unsigned char *new_head, const char *msg)
305 struct strbuf reflog_message = STRBUF_INIT;
307 if (!msg)
308 strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
309 else {
310 if (verbosity >= 0)
311 printf("%s\n", msg);
312 strbuf_addf(&reflog_message, "%s: %s",
313 getenv("GIT_REFLOG_ACTION"), msg);
315 if (squash) {
316 squash_message();
317 } else {
318 if (verbosity >= 0 && !merge_msg.len)
319 printf("No merge message -- not updating HEAD\n");
320 else {
321 const char *argv_gc_auto[] = { "gc", "--auto", NULL };
322 update_ref(reflog_message.buf, "HEAD",
323 new_head, head, 0,
324 DIE_ON_ERR);
326 * We ignore errors in 'gc --auto', since the
327 * user should see them.
329 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
332 if (new_head && show_diffstat) {
333 struct diff_options opts;
334 diff_setup(&opts);
335 opts.output_format |=
336 DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
337 opts.detect_rename = DIFF_DETECT_RENAME;
338 if (diff_use_color_default > 0)
339 DIFF_OPT_SET(&opts, COLOR_DIFF);
340 if (diff_setup_done(&opts) < 0)
341 die("diff_setup_done failed");
342 diff_tree_sha1(head, new_head, "", &opts);
343 diffcore_std(&opts);
344 diff_flush(&opts);
347 /* Run a post-merge hook */
348 run_hook(NULL, "post-merge", squash ? "1" : "0", NULL);
350 strbuf_release(&reflog_message);
353 /* Get the name for the merge commit's message. */
354 static void merge_name(const char *remote, struct strbuf *msg)
356 struct object *remote_head;
357 unsigned char branch_head[20], buf_sha[20];
358 struct strbuf buf = STRBUF_INIT;
359 struct strbuf bname = STRBUF_INIT;
360 const char *ptr;
361 char *found_ref;
362 int len, early;
364 strbuf_branchname(&bname, remote);
365 remote = bname.buf;
367 memset(branch_head, 0, sizeof(branch_head));
368 remote_head = peel_to_type(remote, 0, NULL, OBJ_COMMIT);
369 if (!remote_head)
370 die("'%s' does not point to a commit", remote);
372 if (dwim_ref(remote, strlen(remote), branch_head, &found_ref) > 0) {
373 if (!prefixcmp(found_ref, "refs/heads/")) {
374 strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
375 sha1_to_hex(branch_head), remote);
376 goto cleanup;
378 if (!prefixcmp(found_ref, "refs/remotes/")) {
379 strbuf_addf(msg, "%s\t\tremote branch '%s' of .\n",
380 sha1_to_hex(branch_head), remote);
381 goto cleanup;
385 /* See if remote matches <name>^^^.. or <name>~<number> */
386 for (len = 0, ptr = remote + strlen(remote);
387 remote < ptr && ptr[-1] == '^';
388 ptr--)
389 len++;
390 if (len)
391 early = 1;
392 else {
393 early = 0;
394 ptr = strrchr(remote, '~');
395 if (ptr) {
396 int seen_nonzero = 0;
398 len++; /* count ~ */
399 while (*++ptr && isdigit(*ptr)) {
400 seen_nonzero |= (*ptr != '0');
401 len++;
403 if (*ptr)
404 len = 0; /* not ...~<number> */
405 else if (seen_nonzero)
406 early = 1;
407 else if (len == 1)
408 early = 1; /* "name~" is "name~1"! */
411 if (len) {
412 struct strbuf truname = STRBUF_INIT;
413 strbuf_addstr(&truname, "refs/heads/");
414 strbuf_addstr(&truname, remote);
415 strbuf_setlen(&truname, truname.len - len);
416 if (resolve_ref(truname.buf, buf_sha, 0, NULL)) {
417 strbuf_addf(msg,
418 "%s\t\tbranch '%s'%s of .\n",
419 sha1_to_hex(remote_head->sha1),
420 truname.buf + 11,
421 (early ? " (early part)" : ""));
422 strbuf_release(&truname);
423 goto cleanup;
427 if (!strcmp(remote, "FETCH_HEAD") &&
428 !access(git_path("FETCH_HEAD"), R_OK)) {
429 FILE *fp;
430 struct strbuf line = STRBUF_INIT;
431 char *ptr;
433 fp = fopen(git_path("FETCH_HEAD"), "r");
434 if (!fp)
435 die_errno("could not open '%s' for reading",
436 git_path("FETCH_HEAD"));
437 strbuf_getline(&line, fp, '\n');
438 fclose(fp);
439 ptr = strstr(line.buf, "\tnot-for-merge\t");
440 if (ptr)
441 strbuf_remove(&line, ptr-line.buf+1, 13);
442 strbuf_addbuf(msg, &line);
443 strbuf_release(&line);
444 goto cleanup;
446 strbuf_addf(msg, "%s\t\tcommit '%s'\n",
447 sha1_to_hex(remote_head->sha1), remote);
448 cleanup:
449 strbuf_release(&buf);
450 strbuf_release(&bname);
453 static int git_merge_config(const char *k, const char *v, void *cb)
455 if (branch && !prefixcmp(k, "branch.") &&
456 !prefixcmp(k + 7, branch) &&
457 !strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
458 const char **argv;
459 int argc;
460 char *buf;
462 buf = xstrdup(v);
463 argc = split_cmdline(buf, &argv);
464 if (argc < 0)
465 die("Bad branch.%s.mergeoptions string", branch);
466 argv = xrealloc(argv, sizeof(*argv) * (argc + 2));
467 memmove(argv + 1, argv, sizeof(*argv) * (argc + 1));
468 argc++;
469 parse_options(argc, argv, NULL, builtin_merge_options,
470 builtin_merge_usage, 0);
471 free(buf);
474 if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
475 show_diffstat = git_config_bool(k, v);
476 else if (!strcmp(k, "pull.twohead"))
477 return git_config_string(&pull_twohead, k, v);
478 else if (!strcmp(k, "pull.octopus"))
479 return git_config_string(&pull_octopus, k, v);
480 else if (!strcmp(k, "merge.log") || !strcmp(k, "merge.summary"))
481 option_log = git_config_bool(k, v);
482 return git_diff_ui_config(k, v, cb);
485 static int read_tree_trivial(unsigned char *common, unsigned char *head,
486 unsigned char *one)
488 int i, nr_trees = 0;
489 struct tree *trees[MAX_UNPACK_TREES];
490 struct tree_desc t[MAX_UNPACK_TREES];
491 struct unpack_trees_options opts;
493 memset(&opts, 0, sizeof(opts));
494 opts.head_idx = 2;
495 opts.src_index = &the_index;
496 opts.dst_index = &the_index;
497 opts.update = 1;
498 opts.verbose_update = 1;
499 opts.trivial_merges_only = 1;
500 opts.merge = 1;
501 trees[nr_trees] = parse_tree_indirect(common);
502 if (!trees[nr_trees++])
503 return -1;
504 trees[nr_trees] = parse_tree_indirect(head);
505 if (!trees[nr_trees++])
506 return -1;
507 trees[nr_trees] = parse_tree_indirect(one);
508 if (!trees[nr_trees++])
509 return -1;
510 opts.fn = threeway_merge;
511 cache_tree_free(&active_cache_tree);
512 for (i = 0; i < nr_trees; i++) {
513 parse_tree(trees[i]);
514 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
516 if (unpack_trees(nr_trees, t, &opts))
517 return -1;
518 return 0;
521 static void write_tree_trivial(unsigned char *sha1)
523 if (write_cache_as_tree(sha1, 0, NULL))
524 die("git write-tree failed to write a tree");
527 static int try_merge_strategy(const char *strategy, struct commit_list *common,
528 const char *head_arg)
530 const char **args;
531 int i = 0, ret;
532 struct commit_list *j;
533 struct strbuf buf = STRBUF_INIT;
534 int index_fd;
535 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
537 index_fd = hold_locked_index(lock, 1);
538 refresh_cache(REFRESH_QUIET);
539 if (active_cache_changed &&
540 (write_cache(index_fd, active_cache, active_nr) ||
541 commit_locked_index(lock)))
542 return error("Unable to write index.");
543 rollback_lock_file(lock);
545 if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
546 int clean;
547 struct commit *result;
548 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
549 int index_fd;
550 struct commit_list *reversed = NULL;
551 struct merge_options o;
553 if (remoteheads->next) {
554 error("Not handling anything other than two heads merge.");
555 return 2;
558 init_merge_options(&o);
559 if (!strcmp(strategy, "subtree"))
560 o.subtree_merge = 1;
562 o.branch1 = head_arg;
563 o.branch2 = remoteheads->item->util;
565 for (j = common; j; j = j->next)
566 commit_list_insert(j->item, &reversed);
568 index_fd = hold_locked_index(lock, 1);
569 clean = merge_recursive(&o, lookup_commit(head),
570 remoteheads->item, reversed, &result);
571 if (active_cache_changed &&
572 (write_cache(index_fd, active_cache, active_nr) ||
573 commit_locked_index(lock)))
574 die ("unable to write %s", get_index_file());
575 rollback_lock_file(lock);
576 return clean ? 0 : 1;
577 } else {
578 args = xmalloc((4 + commit_list_count(common) +
579 commit_list_count(remoteheads)) * sizeof(char *));
580 strbuf_addf(&buf, "merge-%s", strategy);
581 args[i++] = buf.buf;
582 for (j = common; j; j = j->next)
583 args[i++] = xstrdup(sha1_to_hex(j->item->object.sha1));
584 args[i++] = "--";
585 args[i++] = head_arg;
586 for (j = remoteheads; j; j = j->next)
587 args[i++] = xstrdup(sha1_to_hex(j->item->object.sha1));
588 args[i] = NULL;
589 ret = run_command_v_opt(args, RUN_GIT_CMD);
590 strbuf_release(&buf);
591 i = 1;
592 for (j = common; j; j = j->next)
593 free((void *)args[i++]);
594 i += 2;
595 for (j = remoteheads; j; j = j->next)
596 free((void *)args[i++]);
597 free(args);
598 discard_cache();
599 if (read_cache() < 0)
600 die("failed to read the cache");
601 return ret;
605 static void count_diff_files(struct diff_queue_struct *q,
606 struct diff_options *opt, void *data)
608 int *count = data;
610 (*count) += q->nr;
613 static int count_unmerged_entries(void)
615 const struct index_state *state = &the_index;
616 int i, ret = 0;
618 for (i = 0; i < state->cache_nr; i++)
619 if (ce_stage(state->cache[i]))
620 ret++;
622 return ret;
625 static int checkout_fast_forward(unsigned char *head, unsigned char *remote)
627 struct tree *trees[MAX_UNPACK_TREES];
628 struct unpack_trees_options opts;
629 struct tree_desc t[MAX_UNPACK_TREES];
630 int i, fd, nr_trees = 0;
631 struct dir_struct dir;
632 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
634 refresh_cache(REFRESH_QUIET);
636 fd = hold_locked_index(lock_file, 1);
638 memset(&trees, 0, sizeof(trees));
639 memset(&opts, 0, sizeof(opts));
640 memset(&t, 0, sizeof(t));
641 memset(&dir, 0, sizeof(dir));
642 dir.flags |= DIR_SHOW_IGNORED;
643 dir.exclude_per_dir = ".gitignore";
644 opts.dir = &dir;
646 opts.head_idx = 1;
647 opts.src_index = &the_index;
648 opts.dst_index = &the_index;
649 opts.update = 1;
650 opts.verbose_update = 1;
651 opts.merge = 1;
652 opts.fn = twoway_merge;
654 trees[nr_trees] = parse_tree_indirect(head);
655 if (!trees[nr_trees++])
656 return -1;
657 trees[nr_trees] = parse_tree_indirect(remote);
658 if (!trees[nr_trees++])
659 return -1;
660 for (i = 0; i < nr_trees; i++) {
661 parse_tree(trees[i]);
662 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
664 if (unpack_trees(nr_trees, t, &opts))
665 return -1;
666 if (write_cache(fd, active_cache, active_nr) ||
667 commit_locked_index(lock_file))
668 die("unable to write new index file");
669 return 0;
672 static void split_merge_strategies(const char *string, struct strategy **list,
673 int *nr, int *alloc)
675 char *p, *q, *buf;
677 if (!string)
678 return;
680 buf = xstrdup(string);
681 q = buf;
682 for (;;) {
683 p = strchr(q, ' ');
684 if (!p) {
685 ALLOC_GROW(*list, *nr + 1, *alloc);
686 (*list)[(*nr)++].name = xstrdup(q);
687 free(buf);
688 return;
689 } else {
690 *p = '\0';
691 ALLOC_GROW(*list, *nr + 1, *alloc);
692 (*list)[(*nr)++].name = xstrdup(q);
693 q = ++p;
698 static void add_strategies(const char *string, unsigned attr)
700 struct strategy *list = NULL;
701 int list_alloc = 0, list_nr = 0, i;
703 memset(&list, 0, sizeof(list));
704 split_merge_strategies(string, &list, &list_nr, &list_alloc);
705 if (list) {
706 for (i = 0; i < list_nr; i++)
707 append_strategy(get_strategy(list[i].name));
708 return;
710 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
711 if (all_strategy[i].attr & attr)
712 append_strategy(&all_strategy[i]);
716 static int merge_trivial(void)
718 unsigned char result_tree[20], result_commit[20];
719 struct commit_list *parent = xmalloc(sizeof(*parent));
721 write_tree_trivial(result_tree);
722 printf("Wonderful.\n");
723 parent->item = lookup_commit(head);
724 parent->next = xmalloc(sizeof(*parent->next));
725 parent->next->item = remoteheads->item;
726 parent->next->next = NULL;
727 commit_tree(merge_msg.buf, result_tree, parent, result_commit, NULL);
728 finish(result_commit, "In-index merge");
729 drop_save();
730 return 0;
733 static int finish_automerge(struct commit_list *common,
734 unsigned char *result_tree,
735 const char *wt_strategy)
737 struct commit_list *parents = NULL, *j;
738 struct strbuf buf = STRBUF_INIT;
739 unsigned char result_commit[20];
741 free_commit_list(common);
742 if (allow_fast_forward) {
743 parents = remoteheads;
744 commit_list_insert(lookup_commit(head), &parents);
745 parents = reduce_heads(parents);
746 } else {
747 struct commit_list **pptr = &parents;
749 pptr = &commit_list_insert(lookup_commit(head),
750 pptr)->next;
751 for (j = remoteheads; j; j = j->next)
752 pptr = &commit_list_insert(j->item, pptr)->next;
754 free_commit_list(remoteheads);
755 strbuf_addch(&merge_msg, '\n');
756 commit_tree(merge_msg.buf, result_tree, parents, result_commit, NULL);
757 strbuf_addf(&buf, "Merge made by %s.", wt_strategy);
758 finish(result_commit, buf.buf);
759 strbuf_release(&buf);
760 drop_save();
761 return 0;
764 static int suggest_conflicts(void)
766 FILE *fp;
767 int pos;
769 fp = fopen(git_path("MERGE_MSG"), "a");
770 if (!fp)
771 die_errno("Could not open '%s' for writing",
772 git_path("MERGE_MSG"));
773 fprintf(fp, "\nConflicts:\n");
774 for (pos = 0; pos < active_nr; pos++) {
775 struct cache_entry *ce = active_cache[pos];
777 if (ce_stage(ce)) {
778 fprintf(fp, "\t%s\n", ce->name);
779 while (pos + 1 < active_nr &&
780 !strcmp(ce->name,
781 active_cache[pos + 1]->name))
782 pos++;
785 fclose(fp);
786 rerere();
787 printf("Automatic merge failed; "
788 "fix conflicts and then commit the result.\n");
789 return 1;
792 static struct commit *is_old_style_invocation(int argc, const char **argv)
794 struct commit *second_token = NULL;
795 if (argc > 1) {
796 unsigned char second_sha1[20];
798 if (get_sha1(argv[1], second_sha1))
799 return NULL;
800 second_token = lookup_commit_reference_gently(second_sha1, 0);
801 if (!second_token)
802 die("'%s' is not a commit", argv[1]);
803 if (hashcmp(second_token->object.sha1, head))
804 return NULL;
806 return second_token;
809 static int evaluate_result(void)
811 int cnt = 0;
812 struct rev_info rev;
814 /* Check how many files differ. */
815 init_revisions(&rev, "");
816 setup_revisions(0, NULL, &rev, NULL);
817 rev.diffopt.output_format |=
818 DIFF_FORMAT_CALLBACK;
819 rev.diffopt.format_callback = count_diff_files;
820 rev.diffopt.format_callback_data = &cnt;
821 run_diff_files(&rev, 0);
824 * Check how many unmerged entries are
825 * there.
827 cnt += count_unmerged_entries();
829 return cnt;
832 int cmd_merge(int argc, const char **argv, const char *prefix)
834 unsigned char result_tree[20];
835 struct strbuf buf = STRBUF_INIT;
836 const char *head_arg;
837 int flag, head_invalid = 0, i;
838 int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
839 struct commit_list *common = NULL;
840 const char *best_strategy = NULL, *wt_strategy = NULL;
841 struct commit_list **remotes = &remoteheads;
843 setup_work_tree();
844 if (file_exists(git_path("MERGE_HEAD")))
845 die("You have not concluded your merge. (MERGE_HEAD exists)");
846 if (read_cache_unmerged())
847 die("You are in the middle of a conflicted merge."
848 " (index unmerged)");
851 * Check if we are _not_ on a detached HEAD, i.e. if there is a
852 * current branch.
854 branch = resolve_ref("HEAD", head, 0, &flag);
855 if (branch && !prefixcmp(branch, "refs/heads/"))
856 branch += 11;
857 if (is_null_sha1(head))
858 head_invalid = 1;
860 git_config(git_merge_config, NULL);
862 /* for color.ui */
863 if (diff_use_color_default == -1)
864 diff_use_color_default = git_use_color_default;
866 argc = parse_options(argc, argv, prefix, builtin_merge_options,
867 builtin_merge_usage, 0);
868 if (verbosity < 0)
869 show_diffstat = 0;
871 if (squash) {
872 if (!allow_fast_forward)
873 die("You cannot combine --squash with --no-ff.");
874 option_commit = 0;
877 if (!argc)
878 usage_with_options(builtin_merge_usage,
879 builtin_merge_options);
882 * This could be traditional "merge <msg> HEAD <commit>..." and
883 * the way we can tell it is to see if the second token is HEAD,
884 * but some people might have misused the interface and used a
885 * committish that is the same as HEAD there instead.
886 * Traditional format never would have "-m" so it is an
887 * additional safety measure to check for it.
890 if (!have_message && is_old_style_invocation(argc, argv)) {
891 strbuf_addstr(&merge_msg, argv[0]);
892 head_arg = argv[1];
893 argv += 2;
894 argc -= 2;
895 } else if (head_invalid) {
896 struct object *remote_head;
898 * If the merged head is a valid one there is no reason
899 * to forbid "git merge" into a branch yet to be born.
900 * We do the same for "git pull".
902 if (argc != 1)
903 die("Can merge only exactly one commit into "
904 "empty head");
905 if (squash)
906 die("Squash commit into empty head not supported yet");
907 if (!allow_fast_forward)
908 die("Non-fast-forward commit does not make sense into "
909 "an empty head");
910 remote_head = peel_to_type(argv[0], 0, NULL, OBJ_COMMIT);
911 if (!remote_head)
912 die("%s - not something we can merge", argv[0]);
913 update_ref("initial pull", "HEAD", remote_head->sha1, NULL, 0,
914 DIE_ON_ERR);
915 reset_hard(remote_head->sha1, 0);
916 return 0;
917 } else {
918 struct strbuf msg = STRBUF_INIT;
920 /* We are invoked directly as the first-class UI. */
921 head_arg = "HEAD";
924 * All the rest are the commits being merged;
925 * prepare the standard merge summary message to
926 * be appended to the given message. If remote
927 * is invalid we will die later in the common
928 * codepath so we discard the error in this
929 * loop.
931 for (i = 0; i < argc; i++)
932 merge_name(argv[i], &msg);
933 fmt_merge_msg(option_log, &msg, &merge_msg);
934 if (merge_msg.len)
935 strbuf_setlen(&merge_msg, merge_msg.len-1);
938 if (head_invalid || !argc)
939 usage_with_options(builtin_merge_usage,
940 builtin_merge_options);
942 strbuf_addstr(&buf, "merge");
943 for (i = 0; i < argc; i++)
944 strbuf_addf(&buf, " %s", argv[i]);
945 setenv("GIT_REFLOG_ACTION", buf.buf, 0);
946 strbuf_reset(&buf);
948 for (i = 0; i < argc; i++) {
949 struct object *o;
950 struct commit *commit;
952 o = peel_to_type(argv[i], 0, NULL, OBJ_COMMIT);
953 if (!o)
954 die("%s - not something we can merge", argv[i]);
955 commit = lookup_commit(o->sha1);
956 commit->util = (void *)argv[i];
957 remotes = &commit_list_insert(commit, remotes)->next;
959 strbuf_addf(&buf, "GITHEAD_%s", sha1_to_hex(o->sha1));
960 setenv(buf.buf, argv[i], 1);
961 strbuf_reset(&buf);
964 if (!use_strategies) {
965 if (!remoteheads->next)
966 add_strategies(pull_twohead, DEFAULT_TWOHEAD);
967 else
968 add_strategies(pull_octopus, DEFAULT_OCTOPUS);
971 for (i = 0; i < use_strategies_nr; i++) {
972 if (use_strategies[i]->attr & NO_FAST_FORWARD)
973 allow_fast_forward = 0;
974 if (use_strategies[i]->attr & NO_TRIVIAL)
975 allow_trivial = 0;
978 if (!remoteheads->next)
979 common = get_merge_bases(lookup_commit(head),
980 remoteheads->item, 1);
981 else {
982 struct commit_list *list = remoteheads;
983 commit_list_insert(lookup_commit(head), &list);
984 common = get_octopus_merge_bases(list);
985 free(list);
988 update_ref("updating ORIG_HEAD", "ORIG_HEAD", head, NULL, 0,
989 DIE_ON_ERR);
991 if (!common)
992 ; /* No common ancestors found. We need a real merge. */
993 else if (!remoteheads->next && !common->next &&
994 common->item == remoteheads->item) {
996 * If head can reach all the merge then we are up to date.
997 * but first the most common case of merging one remote.
999 finish_up_to_date("Already up-to-date.");
1000 return 0;
1001 } else if (allow_fast_forward && !remoteheads->next &&
1002 !common->next &&
1003 !hashcmp(common->item->object.sha1, head)) {
1004 /* Again the most common case of merging one remote. */
1005 struct strbuf msg = STRBUF_INIT;
1006 struct object *o;
1007 char hex[41];
1009 strcpy(hex, find_unique_abbrev(head, DEFAULT_ABBREV));
1011 if (verbosity >= 0)
1012 printf("Updating %s..%s\n",
1013 hex,
1014 find_unique_abbrev(remoteheads->item->object.sha1,
1015 DEFAULT_ABBREV));
1016 strbuf_addstr(&msg, "Fast forward");
1017 if (have_message)
1018 strbuf_addstr(&msg,
1019 " (no commit created; -m option ignored)");
1020 o = peel_to_type(sha1_to_hex(remoteheads->item->object.sha1),
1021 0, NULL, OBJ_COMMIT);
1022 if (!o)
1023 return 1;
1025 if (checkout_fast_forward(head, remoteheads->item->object.sha1))
1026 return 1;
1028 finish(o->sha1, msg.buf);
1029 drop_save();
1030 return 0;
1031 } else if (!remoteheads->next && common->next)
1034 * We are not doing octopus and not fast forward. Need
1035 * a real merge.
1037 else if (!remoteheads->next && !common->next && option_commit) {
1039 * We are not doing octopus, not fast forward, and have
1040 * only one common.
1042 refresh_cache(REFRESH_QUIET);
1043 if (allow_trivial) {
1044 /* See if it is really trivial. */
1045 git_committer_info(IDENT_ERROR_ON_NO_NAME);
1046 printf("Trying really trivial in-index merge...\n");
1047 if (!read_tree_trivial(common->item->object.sha1,
1048 head, remoteheads->item->object.sha1))
1049 return merge_trivial();
1050 printf("Nope.\n");
1052 } else {
1054 * An octopus. If we can reach all the remote we are up
1055 * to date.
1057 int up_to_date = 1;
1058 struct commit_list *j;
1060 for (j = remoteheads; j; j = j->next) {
1061 struct commit_list *common_one;
1064 * Here we *have* to calculate the individual
1065 * merge_bases again, otherwise "git merge HEAD^
1066 * HEAD^^" would be missed.
1068 common_one = get_merge_bases(lookup_commit(head),
1069 j->item, 1);
1070 if (hashcmp(common_one->item->object.sha1,
1071 j->item->object.sha1)) {
1072 up_to_date = 0;
1073 break;
1076 if (up_to_date) {
1077 finish_up_to_date("Already up-to-date. Yeeah!");
1078 return 0;
1082 /* We are going to make a new commit. */
1083 git_committer_info(IDENT_ERROR_ON_NO_NAME);
1086 * At this point, we need a real merge. No matter what strategy
1087 * we use, it would operate on the index, possibly affecting the
1088 * working tree, and when resolved cleanly, have the desired
1089 * tree in the index -- this means that the index must be in
1090 * sync with the head commit. The strategies are responsible
1091 * to ensure this.
1093 if (use_strategies_nr != 1) {
1095 * Stash away the local changes so that we can try more
1096 * than one.
1098 save_state();
1099 } else {
1100 memcpy(stash, null_sha1, 20);
1103 for (i = 0; i < use_strategies_nr; i++) {
1104 int ret;
1105 if (i) {
1106 printf("Rewinding the tree to pristine...\n");
1107 restore_state();
1109 if (use_strategies_nr != 1)
1110 printf("Trying merge strategy %s...\n",
1111 use_strategies[i]->name);
1113 * Remember which strategy left the state in the working
1114 * tree.
1116 wt_strategy = use_strategies[i]->name;
1118 ret = try_merge_strategy(use_strategies[i]->name,
1119 common, head_arg);
1120 if (!option_commit && !ret) {
1121 merge_was_ok = 1;
1123 * This is necessary here just to avoid writing
1124 * the tree, but later we will *not* exit with
1125 * status code 1 because merge_was_ok is set.
1127 ret = 1;
1130 if (ret) {
1132 * The backend exits with 1 when conflicts are
1133 * left to be resolved, with 2 when it does not
1134 * handle the given merge at all.
1136 if (ret == 1) {
1137 int cnt = evaluate_result();
1139 if (best_cnt <= 0 || cnt <= best_cnt) {
1140 best_strategy = use_strategies[i]->name;
1141 best_cnt = cnt;
1144 if (merge_was_ok)
1145 break;
1146 else
1147 continue;
1150 /* Automerge succeeded. */
1151 write_tree_trivial(result_tree);
1152 automerge_was_ok = 1;
1153 break;
1157 * If we have a resulting tree, that means the strategy module
1158 * auto resolved the merge cleanly.
1160 if (automerge_was_ok)
1161 return finish_automerge(common, result_tree, wt_strategy);
1164 * Pick the result from the best strategy and have the user fix
1165 * it up.
1167 if (!best_strategy) {
1168 restore_state();
1169 if (use_strategies_nr > 1)
1170 fprintf(stderr,
1171 "No merge strategy handled the merge.\n");
1172 else
1173 fprintf(stderr, "Merge with strategy %s failed.\n",
1174 use_strategies[0]->name);
1175 return 2;
1176 } else if (best_strategy == wt_strategy)
1177 ; /* We already have its result in the working tree. */
1178 else {
1179 printf("Rewinding the tree to pristine...\n");
1180 restore_state();
1181 printf("Using the %s to prepare resolving by hand.\n",
1182 best_strategy);
1183 try_merge_strategy(best_strategy, common, head_arg);
1186 if (squash)
1187 finish(NULL, NULL);
1188 else {
1189 int fd;
1190 struct commit_list *j;
1192 for (j = remoteheads; j; j = j->next)
1193 strbuf_addf(&buf, "%s\n",
1194 sha1_to_hex(j->item->object.sha1));
1195 fd = open(git_path("MERGE_HEAD"), O_WRONLY | O_CREAT, 0666);
1196 if (fd < 0)
1197 die_errno("Could not open '%s' for writing",
1198 git_path("MERGE_HEAD"));
1199 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
1200 die_errno("Could not write to '%s'", git_path("MERGE_HEAD"));
1201 close(fd);
1202 strbuf_addch(&merge_msg, '\n');
1203 fd = open(git_path("MERGE_MSG"), O_WRONLY | O_CREAT, 0666);
1204 if (fd < 0)
1205 die_errno("Could not open '%s' for writing",
1206 git_path("MERGE_MSG"));
1207 if (write_in_full(fd, merge_msg.buf, merge_msg.len) !=
1208 merge_msg.len)
1209 die_errno("Could not write to '%s'", git_path("MERGE_MSG"));
1210 close(fd);
1211 fd = open(git_path("MERGE_MODE"), O_WRONLY | O_CREAT | O_TRUNC, 0666);
1212 if (fd < 0)
1213 die_errno("Could not open '%s' for writing",
1214 git_path("MERGE_MODE"));
1215 strbuf_reset(&buf);
1216 if (!allow_fast_forward)
1217 strbuf_addf(&buf, "no-ff");
1218 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
1219 die_errno("Could not write to '%s'", git_path("MERGE_MODE"));
1220 close(fd);
1223 if (merge_was_ok) {
1224 fprintf(stderr, "Automatic merge went well; "
1225 "stopped before committing as requested\n");
1226 return 0;
1227 } else
1228 return suggest_conflicts();