use skip_prefix to avoid repeating strings
[git.git] / builtin / checkout.c
blob463cfeea5067fe02d8eb1414018c97ff9a757176
1 #include "cache.h"
2 #include "builtin.h"
3 #include "parse-options.h"
4 #include "refs.h"
5 #include "commit.h"
6 #include "tree.h"
7 #include "tree-walk.h"
8 #include "cache-tree.h"
9 #include "unpack-trees.h"
10 #include "dir.h"
11 #include "run-command.h"
12 #include "merge-recursive.h"
13 #include "branch.h"
14 #include "diff.h"
15 #include "revision.h"
16 #include "remote.h"
17 #include "blob.h"
18 #include "xdiff-interface.h"
19 #include "ll-merge.h"
20 #include "resolve-undo.h"
21 #include "submodule.h"
22 #include "argv-array.h"
24 static const char * const checkout_usage[] = {
25 N_("git checkout [options] <branch>"),
26 N_("git checkout [options] [<branch>] -- <file>..."),
27 NULL,
30 struct checkout_opts {
31 int patch_mode;
32 int quiet;
33 int merge;
34 int force;
35 int force_detach;
36 int writeout_stage;
37 int overwrite_ignore;
38 int ignore_skipworktree;
40 const char *new_branch;
41 const char *new_branch_force;
42 const char *new_orphan_branch;
43 int new_branch_log;
44 enum branch_track track;
45 struct diff_options diff_options;
47 int branch_exists;
48 const char *prefix;
49 struct pathspec pathspec;
50 struct tree *source_tree;
53 static int post_checkout_hook(struct commit *old, struct commit *new,
54 int changed)
56 return run_hook_le(NULL, "post-checkout",
57 sha1_to_hex(old ? old->object.sha1 : null_sha1),
58 sha1_to_hex(new ? new->object.sha1 : null_sha1),
59 changed ? "1" : "0", NULL);
60 /* "new" can be NULL when checking out from the index before
61 a commit exists. */
65 static int update_some(const unsigned char *sha1, const char *base, int baselen,
66 const char *pathname, unsigned mode, int stage, void *context)
68 int len;
69 struct cache_entry *ce;
71 if (S_ISDIR(mode))
72 return READ_TREE_RECURSIVE;
74 len = baselen + strlen(pathname);
75 ce = xcalloc(1, cache_entry_size(len));
76 hashcpy(ce->sha1, sha1);
77 memcpy(ce->name, base, baselen);
78 memcpy(ce->name + baselen, pathname, len - baselen);
79 ce->ce_flags = create_ce_flags(0) | CE_UPDATE;
80 ce->ce_namelen = len;
81 ce->ce_mode = create_ce_mode(mode);
82 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
83 return 0;
86 static int read_tree_some(struct tree *tree, const struct pathspec *pathspec)
88 read_tree_recursive(tree, "", 0, 0, pathspec, update_some, NULL);
90 /* update the index with the given tree's info
91 * for all args, expanding wildcards, and exit
92 * with any non-zero return code.
94 return 0;
97 static int skip_same_name(const struct cache_entry *ce, int pos)
99 while (++pos < active_nr &&
100 !strcmp(active_cache[pos]->name, ce->name))
101 ; /* skip */
102 return pos;
105 static int check_stage(int stage, const struct cache_entry *ce, int pos)
107 while (pos < active_nr &&
108 !strcmp(active_cache[pos]->name, ce->name)) {
109 if (ce_stage(active_cache[pos]) == stage)
110 return 0;
111 pos++;
113 if (stage == 2)
114 return error(_("path '%s' does not have our version"), ce->name);
115 else
116 return error(_("path '%s' does not have their version"), ce->name);
119 static int check_stages(unsigned stages, const struct cache_entry *ce, int pos)
121 unsigned seen = 0;
122 const char *name = ce->name;
124 while (pos < active_nr) {
125 ce = active_cache[pos];
126 if (strcmp(name, ce->name))
127 break;
128 seen |= (1 << ce_stage(ce));
129 pos++;
131 if ((stages & seen) != stages)
132 return error(_("path '%s' does not have all necessary versions"),
133 name);
134 return 0;
137 static int checkout_stage(int stage, struct cache_entry *ce, int pos,
138 struct checkout *state)
140 while (pos < active_nr &&
141 !strcmp(active_cache[pos]->name, ce->name)) {
142 if (ce_stage(active_cache[pos]) == stage)
143 return checkout_entry(active_cache[pos], state, NULL);
144 pos++;
146 if (stage == 2)
147 return error(_("path '%s' does not have our version"), ce->name);
148 else
149 return error(_("path '%s' does not have their version"), ce->name);
152 static int checkout_merged(int pos, struct checkout *state)
154 struct cache_entry *ce = active_cache[pos];
155 const char *path = ce->name;
156 mmfile_t ancestor, ours, theirs;
157 int status;
158 unsigned char sha1[20];
159 mmbuffer_t result_buf;
160 unsigned char threeway[3][20];
161 unsigned mode = 0;
163 memset(threeway, 0, sizeof(threeway));
164 while (pos < active_nr) {
165 int stage;
166 stage = ce_stage(ce);
167 if (!stage || strcmp(path, ce->name))
168 break;
169 hashcpy(threeway[stage - 1], ce->sha1);
170 if (stage == 2)
171 mode = create_ce_mode(ce->ce_mode);
172 pos++;
173 ce = active_cache[pos];
175 if (is_null_sha1(threeway[1]) || is_null_sha1(threeway[2]))
176 return error(_("path '%s' does not have necessary versions"), path);
178 read_mmblob(&ancestor, threeway[0]);
179 read_mmblob(&ours, threeway[1]);
180 read_mmblob(&theirs, threeway[2]);
183 * NEEDSWORK: re-create conflicts from merges with
184 * merge.renormalize set, too
186 status = ll_merge(&result_buf, path, &ancestor, "base",
187 &ours, "ours", &theirs, "theirs", NULL);
188 free(ancestor.ptr);
189 free(ours.ptr);
190 free(theirs.ptr);
191 if (status < 0 || !result_buf.ptr) {
192 free(result_buf.ptr);
193 return error(_("path '%s': cannot merge"), path);
197 * NEEDSWORK:
198 * There is absolutely no reason to write this as a blob object
199 * and create a phony cache entry just to leak. This hack is
200 * primarily to get to the write_entry() machinery that massages
201 * the contents to work-tree format and writes out which only
202 * allows it for a cache entry. The code in write_entry() needs
203 * to be refactored to allow us to feed a <buffer, size, mode>
204 * instead of a cache entry. Such a refactoring would help
205 * merge_recursive as well (it also writes the merge result to the
206 * object database even when it may contain conflicts).
208 if (write_sha1_file(result_buf.ptr, result_buf.size,
209 blob_type, sha1))
210 die(_("Unable to add merge result for '%s'"), path);
211 ce = make_cache_entry(mode, sha1, path, 2, 0);
212 if (!ce)
213 die(_("make_cache_entry failed for path '%s'"), path);
214 status = checkout_entry(ce, state, NULL);
215 return status;
218 static int checkout_paths(const struct checkout_opts *opts,
219 const char *revision)
221 int pos;
222 struct checkout state;
223 static char *ps_matched;
224 unsigned char rev[20];
225 int flag;
226 struct commit *head;
227 int errs = 0;
228 int newfd;
229 struct lock_file *lock_file;
231 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
232 die(_("'%s' cannot be used with updating paths"), "--track");
234 if (opts->new_branch_log)
235 die(_("'%s' cannot be used with updating paths"), "-l");
237 if (opts->force && opts->patch_mode)
238 die(_("'%s' cannot be used with updating paths"), "-f");
240 if (opts->force_detach)
241 die(_("'%s' cannot be used with updating paths"), "--detach");
243 if (opts->merge && opts->patch_mode)
244 die(_("'%s' cannot be used with %s"), "--merge", "--patch");
246 if (opts->force && opts->merge)
247 die(_("'%s' cannot be used with %s"), "-f", "-m");
249 if (opts->new_branch)
250 die(_("Cannot update paths and switch to branch '%s' at the same time."),
251 opts->new_branch);
253 if (opts->patch_mode)
254 return run_add_interactive(revision, "--patch=checkout",
255 &opts->pathspec);
257 lock_file = xcalloc(1, sizeof(struct lock_file));
259 newfd = hold_locked_index(lock_file, 1);
260 if (read_cache_preload(&opts->pathspec) < 0)
261 return error(_("corrupt index file"));
263 if (opts->source_tree)
264 read_tree_some(opts->source_tree, &opts->pathspec);
266 ps_matched = xcalloc(1, opts->pathspec.nr);
269 * Make sure all pathspecs participated in locating the paths
270 * to be checked out.
272 for (pos = 0; pos < active_nr; pos++) {
273 struct cache_entry *ce = active_cache[pos];
274 ce->ce_flags &= ~CE_MATCHED;
275 if (!opts->ignore_skipworktree && ce_skip_worktree(ce))
276 continue;
277 if (opts->source_tree && !(ce->ce_flags & CE_UPDATE))
279 * "git checkout tree-ish -- path", but this entry
280 * is in the original index; it will not be checked
281 * out to the working tree and it does not matter
282 * if pathspec matched this entry. We will not do
283 * anything to this entry at all.
285 continue;
287 * Either this entry came from the tree-ish we are
288 * checking the paths out of, or we are checking out
289 * of the index.
291 * If it comes from the tree-ish, we already know it
292 * matches the pathspec and could just stamp
293 * CE_MATCHED to it from update_some(). But we still
294 * need ps_matched and read_tree_recursive (and
295 * eventually tree_entry_interesting) cannot fill
296 * ps_matched yet. Once it can, we can avoid calling
297 * match_pathspec() for _all_ entries when
298 * opts->source_tree != NULL.
300 if (ce_path_match(ce, &opts->pathspec, ps_matched))
301 ce->ce_flags |= CE_MATCHED;
304 if (report_path_error(ps_matched, &opts->pathspec, opts->prefix)) {
305 free(ps_matched);
306 return 1;
308 free(ps_matched);
310 /* "checkout -m path" to recreate conflicted state */
311 if (opts->merge)
312 unmerge_marked_index(&the_index);
314 /* Any unmerged paths? */
315 for (pos = 0; pos < active_nr; pos++) {
316 const struct cache_entry *ce = active_cache[pos];
317 if (ce->ce_flags & CE_MATCHED) {
318 if (!ce_stage(ce))
319 continue;
320 if (opts->force) {
321 warning(_("path '%s' is unmerged"), ce->name);
322 } else if (opts->writeout_stage) {
323 errs |= check_stage(opts->writeout_stage, ce, pos);
324 } else if (opts->merge) {
325 errs |= check_stages((1<<2) | (1<<3), ce, pos);
326 } else {
327 errs = 1;
328 error(_("path '%s' is unmerged"), ce->name);
330 pos = skip_same_name(ce, pos) - 1;
333 if (errs)
334 return 1;
336 /* Now we are committed to check them out */
337 memset(&state, 0, sizeof(state));
338 state.force = 1;
339 state.refresh_cache = 1;
340 for (pos = 0; pos < active_nr; pos++) {
341 struct cache_entry *ce = active_cache[pos];
342 if (ce->ce_flags & CE_MATCHED) {
343 if (!ce_stage(ce)) {
344 errs |= checkout_entry(ce, &state, NULL);
345 continue;
347 if (opts->writeout_stage)
348 errs |= checkout_stage(opts->writeout_stage, ce, pos, &state);
349 else if (opts->merge)
350 errs |= checkout_merged(pos, &state);
351 pos = skip_same_name(ce, pos) - 1;
355 if (write_cache(newfd, active_cache, active_nr) ||
356 commit_locked_index(lock_file))
357 die(_("unable to write new index file"));
359 read_ref_full("HEAD", rev, 0, &flag);
360 head = lookup_commit_reference_gently(rev, 1);
362 errs |= post_checkout_hook(head, head, 0);
363 return errs;
366 static void show_local_changes(struct object *head,
367 const struct diff_options *opts)
369 struct rev_info rev;
370 /* I think we want full paths, even if we're in a subdirectory. */
371 init_revisions(&rev, NULL);
372 rev.diffopt.flags = opts->flags;
373 rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
374 diff_setup_done(&rev.diffopt);
375 add_pending_object(&rev, head, NULL);
376 run_diff_index(&rev, 0);
379 static void describe_detached_head(const char *msg, struct commit *commit)
381 struct strbuf sb = STRBUF_INIT;
382 if (!parse_commit(commit))
383 pp_commit_easy(CMIT_FMT_ONELINE, commit, &sb);
384 fprintf(stderr, "%s %s... %s\n", msg,
385 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf);
386 strbuf_release(&sb);
389 static int reset_tree(struct tree *tree, const struct checkout_opts *o,
390 int worktree, int *writeout_error)
392 struct unpack_trees_options opts;
393 struct tree_desc tree_desc;
395 memset(&opts, 0, sizeof(opts));
396 opts.head_idx = -1;
397 opts.update = worktree;
398 opts.skip_unmerged = !worktree;
399 opts.reset = 1;
400 opts.merge = 1;
401 opts.fn = oneway_merge;
402 opts.verbose_update = !o->quiet && isatty(2);
403 opts.src_index = &the_index;
404 opts.dst_index = &the_index;
405 parse_tree(tree);
406 init_tree_desc(&tree_desc, tree->buffer, tree->size);
407 switch (unpack_trees(1, &tree_desc, &opts)) {
408 case -2:
409 *writeout_error = 1;
411 * We return 0 nevertheless, as the index is all right
412 * and more importantly we have made best efforts to
413 * update paths in the work tree, and we cannot revert
414 * them.
416 case 0:
417 return 0;
418 default:
419 return 128;
423 struct branch_info {
424 const char *name; /* The short name used */
425 const char *path; /* The full name of a real branch */
426 struct commit *commit; /* The named commit */
429 static void setup_branch_path(struct branch_info *branch)
431 struct strbuf buf = STRBUF_INIT;
433 strbuf_branchname(&buf, branch->name);
434 if (strcmp(buf.buf, branch->name))
435 branch->name = xstrdup(buf.buf);
436 strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
437 branch->path = strbuf_detach(&buf, NULL);
440 static int merge_working_tree(const struct checkout_opts *opts,
441 struct branch_info *old,
442 struct branch_info *new,
443 int *writeout_error)
445 int ret;
446 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
447 int newfd = hold_locked_index(lock_file, 1);
449 if (read_cache_preload(NULL) < 0)
450 return error(_("corrupt index file"));
452 resolve_undo_clear();
453 if (opts->force) {
454 ret = reset_tree(new->commit->tree, opts, 1, writeout_error);
455 if (ret)
456 return ret;
457 } else {
458 struct tree_desc trees[2];
459 struct tree *tree;
460 struct unpack_trees_options topts;
462 memset(&topts, 0, sizeof(topts));
463 topts.head_idx = -1;
464 topts.src_index = &the_index;
465 topts.dst_index = &the_index;
467 setup_unpack_trees_porcelain(&topts, "checkout");
469 refresh_cache(REFRESH_QUIET);
471 if (unmerged_cache()) {
472 error(_("you need to resolve your current index first"));
473 return 1;
476 /* 2-way merge to the new branch */
477 topts.initial_checkout = is_cache_unborn();
478 topts.update = 1;
479 topts.merge = 1;
480 topts.gently = opts->merge && old->commit;
481 topts.verbose_update = !opts->quiet && isatty(2);
482 topts.fn = twoway_merge;
483 if (opts->overwrite_ignore) {
484 topts.dir = xcalloc(1, sizeof(*topts.dir));
485 topts.dir->flags |= DIR_SHOW_IGNORED;
486 setup_standard_excludes(topts.dir);
488 tree = parse_tree_indirect(old->commit ?
489 old->commit->object.sha1 :
490 EMPTY_TREE_SHA1_BIN);
491 init_tree_desc(&trees[0], tree->buffer, tree->size);
492 tree = parse_tree_indirect(new->commit->object.sha1);
493 init_tree_desc(&trees[1], tree->buffer, tree->size);
495 ret = unpack_trees(2, trees, &topts);
496 if (ret == -1) {
498 * Unpack couldn't do a trivial merge; either
499 * give up or do a real merge, depending on
500 * whether the merge flag was used.
502 struct tree *result;
503 struct tree *work;
504 struct merge_options o;
505 if (!opts->merge)
506 return 1;
509 * Without old->commit, the below is the same as
510 * the two-tree unpack we already tried and failed.
512 if (!old->commit)
513 return 1;
515 /* Do more real merge */
518 * We update the index fully, then write the
519 * tree from the index, then merge the new
520 * branch with the current tree, with the old
521 * branch as the base. Then we reset the index
522 * (but not the working tree) to the new
523 * branch, leaving the working tree as the
524 * merged version, but skipping unmerged
525 * entries in the index.
528 add_files_to_cache(NULL, NULL, 0);
530 * NEEDSWORK: carrying over local changes
531 * when branches have different end-of-line
532 * normalization (or clean+smudge rules) is
533 * a pain; plumb in an option to set
534 * o.renormalize?
536 init_merge_options(&o);
537 o.verbosity = 0;
538 work = write_tree_from_memory(&o);
540 ret = reset_tree(new->commit->tree, opts, 1,
541 writeout_error);
542 if (ret)
543 return ret;
544 o.ancestor = old->name;
545 o.branch1 = new->name;
546 o.branch2 = "local";
547 merge_trees(&o, new->commit->tree, work,
548 old->commit->tree, &result);
549 ret = reset_tree(new->commit->tree, opts, 0,
550 writeout_error);
551 if (ret)
552 return ret;
556 if (write_cache(newfd, active_cache, active_nr) ||
557 commit_locked_index(lock_file))
558 die(_("unable to write new index file"));
560 if (!opts->force && !opts->quiet)
561 show_local_changes(&new->commit->object, &opts->diff_options);
563 return 0;
566 static void report_tracking(struct branch_info *new)
568 struct strbuf sb = STRBUF_INIT;
569 struct branch *branch = branch_get(new->name);
571 if (!format_tracking_info(branch, &sb))
572 return;
573 fputs(sb.buf, stdout);
574 strbuf_release(&sb);
577 static void update_refs_for_switch(const struct checkout_opts *opts,
578 struct branch_info *old,
579 struct branch_info *new)
581 struct strbuf msg = STRBUF_INIT;
582 const char *old_desc, *reflog_msg;
583 if (opts->new_branch) {
584 if (opts->new_orphan_branch) {
585 if (opts->new_branch_log && !log_all_ref_updates) {
586 int temp;
587 char log_file[PATH_MAX];
588 char *ref_name = mkpath("refs/heads/%s", opts->new_orphan_branch);
590 temp = log_all_ref_updates;
591 log_all_ref_updates = 1;
592 if (log_ref_setup(ref_name, log_file, sizeof(log_file))) {
593 fprintf(stderr, _("Can not do reflog for '%s'\n"),
594 opts->new_orphan_branch);
595 log_all_ref_updates = temp;
596 return;
598 log_all_ref_updates = temp;
601 else
602 create_branch(old->name, opts->new_branch, new->name,
603 opts->new_branch_force ? 1 : 0,
604 opts->new_branch_log,
605 opts->new_branch_force ? 1 : 0,
606 opts->quiet,
607 opts->track);
608 new->name = opts->new_branch;
609 setup_branch_path(new);
612 old_desc = old->name;
613 if (!old_desc && old->commit)
614 old_desc = sha1_to_hex(old->commit->object.sha1);
616 reflog_msg = getenv("GIT_REFLOG_ACTION");
617 if (!reflog_msg)
618 strbuf_addf(&msg, "checkout: moving from %s to %s",
619 old_desc ? old_desc : "(invalid)", new->name);
620 else
621 strbuf_insert(&msg, 0, reflog_msg, strlen(reflog_msg));
623 if (!strcmp(new->name, "HEAD") && !new->path && !opts->force_detach) {
624 /* Nothing to do. */
625 } else if (opts->force_detach || !new->path) { /* No longer on any branch. */
626 update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
627 REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
628 if (!opts->quiet) {
629 if (old->path && advice_detached_head)
630 detach_advice(new->name);
631 describe_detached_head(_("HEAD is now at"), new->commit);
633 } else if (new->path) { /* Switch branches. */
634 create_symref("HEAD", new->path, msg.buf);
635 if (!opts->quiet) {
636 if (old->path && !strcmp(new->path, old->path)) {
637 if (opts->new_branch_force)
638 fprintf(stderr, _("Reset branch '%s'\n"),
639 new->name);
640 else
641 fprintf(stderr, _("Already on '%s'\n"),
642 new->name);
643 } else if (opts->new_branch) {
644 if (opts->branch_exists)
645 fprintf(stderr, _("Switched to and reset branch '%s'\n"), new->name);
646 else
647 fprintf(stderr, _("Switched to a new branch '%s'\n"), new->name);
648 } else {
649 fprintf(stderr, _("Switched to branch '%s'\n"),
650 new->name);
653 if (old->path && old->name) {
654 if (!ref_exists(old->path) && reflog_exists(old->path))
655 delete_reflog(old->path);
658 remove_branch_state();
659 strbuf_release(&msg);
660 if (!opts->quiet &&
661 (new->path || (!opts->force_detach && !strcmp(new->name, "HEAD"))))
662 report_tracking(new);
665 static int add_pending_uninteresting_ref(const char *refname,
666 const unsigned char *sha1,
667 int flags, void *cb_data)
669 add_pending_sha1(cb_data, refname, sha1, UNINTERESTING);
670 return 0;
673 static void describe_one_orphan(struct strbuf *sb, struct commit *commit)
675 strbuf_addstr(sb, " ");
676 strbuf_addstr(sb,
677 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
678 strbuf_addch(sb, ' ');
679 if (!parse_commit(commit))
680 pp_commit_easy(CMIT_FMT_ONELINE, commit, sb);
681 strbuf_addch(sb, '\n');
684 #define ORPHAN_CUTOFF 4
685 static void suggest_reattach(struct commit *commit, struct rev_info *revs)
687 struct commit *c, *last = NULL;
688 struct strbuf sb = STRBUF_INIT;
689 int lost = 0;
690 while ((c = get_revision(revs)) != NULL) {
691 if (lost < ORPHAN_CUTOFF)
692 describe_one_orphan(&sb, c);
693 last = c;
694 lost++;
696 if (ORPHAN_CUTOFF < lost) {
697 int more = lost - ORPHAN_CUTOFF;
698 if (more == 1)
699 describe_one_orphan(&sb, last);
700 else
701 strbuf_addf(&sb, _(" ... and %d more.\n"), more);
704 fprintf(stderr,
706 /* The singular version */
707 "Warning: you are leaving %d commit behind, "
708 "not connected to\n"
709 "any of your branches:\n\n"
710 "%s\n",
711 /* The plural version */
712 "Warning: you are leaving %d commits behind, "
713 "not connected to\n"
714 "any of your branches:\n\n"
715 "%s\n",
716 /* Give ngettext() the count */
717 lost),
718 lost,
719 sb.buf);
720 strbuf_release(&sb);
722 if (advice_detached_head)
723 fprintf(stderr,
725 "If you want to keep them by creating a new branch, "
726 "this may be a good time\nto do so with:\n\n"
727 " git branch new_branch_name %s\n\n"),
728 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
732 * We are about to leave commit that was at the tip of a detached
733 * HEAD. If it is not reachable from any ref, this is the last chance
734 * for the user to do so without resorting to reflog.
736 static void orphaned_commit_warning(struct commit *old, struct commit *new)
738 struct rev_info revs;
739 struct object *object = &old->object;
740 struct object_array refs;
742 init_revisions(&revs, NULL);
743 setup_revisions(0, NULL, &revs, NULL);
745 object->flags &= ~UNINTERESTING;
746 add_pending_object(&revs, object, sha1_to_hex(object->sha1));
748 for_each_ref(add_pending_uninteresting_ref, &revs);
749 add_pending_sha1(&revs, "HEAD", new->object.sha1, UNINTERESTING);
751 refs = revs.pending;
752 revs.leak_pending = 1;
754 if (prepare_revision_walk(&revs))
755 die(_("internal error in revision walk"));
756 if (!(old->object.flags & UNINTERESTING))
757 suggest_reattach(old, &revs);
758 else
759 describe_detached_head(_("Previous HEAD position was"), old);
761 clear_commit_marks_for_object_array(&refs, ALL_REV_FLAGS);
762 free(refs.objects);
765 static int switch_branches(const struct checkout_opts *opts,
766 struct branch_info *new)
768 int ret = 0;
769 struct branch_info old;
770 void *path_to_free;
771 unsigned char rev[20];
772 int flag, writeout_error = 0;
773 memset(&old, 0, sizeof(old));
774 old.path = path_to_free = resolve_refdup("HEAD", rev, 0, &flag);
775 old.commit = lookup_commit_reference_gently(rev, 1);
776 if (!(flag & REF_ISSYMREF))
777 old.path = NULL;
779 if (old.path)
780 skip_prefix(old.path, "refs/heads/", &old.name);
782 if (!new->name) {
783 new->name = "HEAD";
784 new->commit = old.commit;
785 if (!new->commit)
786 die(_("You are on a branch yet to be born"));
787 parse_commit_or_die(new->commit);
790 ret = merge_working_tree(opts, &old, new, &writeout_error);
791 if (ret) {
792 free(path_to_free);
793 return ret;
796 if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
797 orphaned_commit_warning(old.commit, new->commit);
799 update_refs_for_switch(opts, &old, new);
801 ret = post_checkout_hook(old.commit, new->commit, 1);
802 free(path_to_free);
803 return ret || writeout_error;
806 static int git_checkout_config(const char *var, const char *value, void *cb)
808 if (!strcmp(var, "diff.ignoresubmodules")) {
809 struct checkout_opts *opts = cb;
810 handle_ignore_submodules_arg(&opts->diff_options, value);
811 return 0;
814 if (starts_with(var, "submodule."))
815 return parse_submodule_config_option(var, value);
817 return git_xmerge_config(var, value, NULL);
820 struct tracking_name_data {
821 /* const */ char *src_ref;
822 char *dst_ref;
823 unsigned char *dst_sha1;
824 int unique;
827 static int check_tracking_name(struct remote *remote, void *cb_data)
829 struct tracking_name_data *cb = cb_data;
830 struct refspec query;
831 memset(&query, 0, sizeof(struct refspec));
832 query.src = cb->src_ref;
833 if (remote_find_tracking(remote, &query) ||
834 get_sha1(query.dst, cb->dst_sha1)) {
835 free(query.dst);
836 return 0;
838 if (cb->dst_ref) {
839 free(query.dst);
840 cb->unique = 0;
841 return 0;
843 cb->dst_ref = query.dst;
844 return 0;
847 static const char *unique_tracking_name(const char *name, unsigned char *sha1)
849 struct tracking_name_data cb_data = { NULL, NULL, NULL, 1 };
850 char src_ref[PATH_MAX];
851 snprintf(src_ref, PATH_MAX, "refs/heads/%s", name);
852 cb_data.src_ref = src_ref;
853 cb_data.dst_sha1 = sha1;
854 for_each_remote(check_tracking_name, &cb_data);
855 if (cb_data.unique)
856 return cb_data.dst_ref;
857 free(cb_data.dst_ref);
858 return NULL;
861 static int parse_branchname_arg(int argc, const char **argv,
862 int dwim_new_local_branch_ok,
863 struct branch_info *new,
864 struct tree **source_tree,
865 unsigned char rev[20],
866 const char **new_branch)
868 int argcount = 0;
869 unsigned char branch_rev[20];
870 const char *arg;
871 int dash_dash_pos;
872 int has_dash_dash = 0;
873 int i;
876 * case 1: git checkout <ref> -- [<paths>]
878 * <ref> must be a valid tree, everything after the '--' must be
879 * a path.
881 * case 2: git checkout -- [<paths>]
883 * everything after the '--' must be paths.
885 * case 3: git checkout <something> [--]
887 * (a) If <something> is a commit, that is to
888 * switch to the branch or detach HEAD at it. As a special case,
889 * if <something> is A...B (missing A or B means HEAD but you can
890 * omit at most one side), and if there is a unique merge base
891 * between A and B, A...B names that merge base.
893 * (b) If <something> is _not_ a commit, either "--" is present
894 * or <something> is not a path, no -t or -b was given, and
895 * and there is a tracking branch whose name is <something>
896 * in one and only one remote, then this is a short-hand to
897 * fork local <something> from that remote-tracking branch.
899 * (c) Otherwise, if "--" is present, treat it like case (1).
901 * (d) Otherwise :
902 * - if it's a reference, treat it like case (1)
903 * - else if it's a path, treat it like case (2)
904 * - else: fail.
906 * case 4: git checkout <something> <paths>
908 * The first argument must not be ambiguous.
909 * - If it's *only* a reference, treat it like case (1).
910 * - If it's only a path, treat it like case (2).
911 * - else: fail.
914 if (!argc)
915 return 0;
917 arg = argv[0];
918 dash_dash_pos = -1;
919 for (i = 0; i < argc; i++) {
920 if (!strcmp(argv[i], "--")) {
921 dash_dash_pos = i;
922 break;
925 if (dash_dash_pos == 0)
926 return 1; /* case (2) */
927 else if (dash_dash_pos == 1)
928 has_dash_dash = 1; /* case (3) or (1) */
929 else if (dash_dash_pos >= 2)
930 die(_("only one reference expected, %d given."), dash_dash_pos);
932 if (!strcmp(arg, "-"))
933 arg = "@{-1}";
935 if (get_sha1_mb(arg, rev)) {
937 * Either case (3) or (4), with <something> not being
938 * a commit, or an attempt to use case (1) with an
939 * invalid ref.
941 * It's likely an error, but we need to find out if
942 * we should auto-create the branch, case (3).(b).
944 int recover_with_dwim = dwim_new_local_branch_ok;
946 if (check_filename(NULL, arg) && !has_dash_dash)
947 recover_with_dwim = 0;
949 * Accept "git checkout foo" and "git checkout foo --"
950 * as candidates for dwim.
952 if (!(argc == 1 && !has_dash_dash) &&
953 !(argc == 2 && has_dash_dash))
954 recover_with_dwim = 0;
956 if (recover_with_dwim) {
957 const char *remote = unique_tracking_name(arg, rev);
958 if (remote) {
959 *new_branch = arg;
960 arg = remote;
961 /* DWIMmed to create local branch, case (3).(b) */
962 } else {
963 recover_with_dwim = 0;
967 if (!recover_with_dwim) {
968 if (has_dash_dash)
969 die(_("invalid reference: %s"), arg);
970 return argcount;
974 /* we can't end up being in (2) anymore, eat the argument */
975 argcount++;
976 argv++;
977 argc--;
979 new->name = arg;
980 setup_branch_path(new);
982 if (!check_refname_format(new->path, 0) &&
983 !read_ref(new->path, branch_rev))
984 hashcpy(rev, branch_rev);
985 else
986 new->path = NULL; /* not an existing branch */
988 new->commit = lookup_commit_reference_gently(rev, 1);
989 if (!new->commit) {
990 /* not a commit */
991 *source_tree = parse_tree_indirect(rev);
992 } else {
993 parse_commit_or_die(new->commit);
994 *source_tree = new->commit->tree;
997 if (!*source_tree) /* case (1): want a tree */
998 die(_("reference is not a tree: %s"), arg);
999 if (!has_dash_dash) {/* case (3).(d) -> (1) */
1001 * Do not complain the most common case
1002 * git checkout branch
1003 * even if there happen to be a file called 'branch';
1004 * it would be extremely annoying.
1006 if (argc)
1007 verify_non_filename(NULL, arg);
1008 } else {
1009 argcount++;
1010 argv++;
1011 argc--;
1014 return argcount;
1017 static int switch_unborn_to_new_branch(const struct checkout_opts *opts)
1019 int status;
1020 struct strbuf branch_ref = STRBUF_INIT;
1022 if (!opts->new_branch)
1023 die(_("You are on a branch yet to be born"));
1024 strbuf_addf(&branch_ref, "refs/heads/%s", opts->new_branch);
1025 status = create_symref("HEAD", branch_ref.buf, "checkout -b");
1026 strbuf_release(&branch_ref);
1027 if (!opts->quiet)
1028 fprintf(stderr, _("Switched to a new branch '%s'\n"),
1029 opts->new_branch);
1030 return status;
1033 static int checkout_branch(struct checkout_opts *opts,
1034 struct branch_info *new)
1036 if (opts->pathspec.nr)
1037 die(_("paths cannot be used with switching branches"));
1039 if (opts->patch_mode)
1040 die(_("'%s' cannot be used with switching branches"),
1041 "--patch");
1043 if (opts->writeout_stage)
1044 die(_("'%s' cannot be used with switching branches"),
1045 "--ours/--theirs");
1047 if (opts->force && opts->merge)
1048 die(_("'%s' cannot be used with '%s'"), "-f", "-m");
1050 if (opts->force_detach && opts->new_branch)
1051 die(_("'%s' cannot be used with '%s'"),
1052 "--detach", "-b/-B/--orphan");
1054 if (opts->new_orphan_branch) {
1055 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1056 die(_("'%s' cannot be used with '%s'"), "--orphan", "-t");
1057 } else if (opts->force_detach) {
1058 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1059 die(_("'%s' cannot be used with '%s'"), "--detach", "-t");
1060 } else if (opts->track == BRANCH_TRACK_UNSPECIFIED)
1061 opts->track = git_branch_track;
1063 if (new->name && !new->commit)
1064 die(_("Cannot switch branch to a non-commit '%s'"),
1065 new->name);
1067 if (!new->commit && opts->new_branch) {
1068 unsigned char rev[20];
1069 int flag;
1071 if (!read_ref_full("HEAD", rev, 0, &flag) &&
1072 (flag & REF_ISSYMREF) && is_null_sha1(rev))
1073 return switch_unborn_to_new_branch(opts);
1075 return switch_branches(opts, new);
1078 int cmd_checkout(int argc, const char **argv, const char *prefix)
1080 struct checkout_opts opts;
1081 struct branch_info new;
1082 char *conflict_style = NULL;
1083 int dwim_new_local_branch = 1;
1084 struct option options[] = {
1085 OPT__QUIET(&opts.quiet, N_("suppress progress reporting")),
1086 OPT_STRING('b', NULL, &opts.new_branch, N_("branch"),
1087 N_("create and checkout a new branch")),
1088 OPT_STRING('B', NULL, &opts.new_branch_force, N_("branch"),
1089 N_("create/reset and checkout a branch")),
1090 OPT_BOOL('l', NULL, &opts.new_branch_log, N_("create reflog for new branch")),
1091 OPT_BOOL(0, "detach", &opts.force_detach, N_("detach the HEAD at named commit")),
1092 OPT_SET_INT('t', "track", &opts.track, N_("set upstream info for new branch"),
1093 BRANCH_TRACK_EXPLICIT),
1094 OPT_STRING(0, "orphan", &opts.new_orphan_branch, N_("new-branch"), N_("new unparented branch")),
1095 OPT_SET_INT('2', "ours", &opts.writeout_stage, N_("checkout our version for unmerged files"),
1097 OPT_SET_INT('3', "theirs", &opts.writeout_stage, N_("checkout their version for unmerged files"),
1099 OPT__FORCE(&opts.force, N_("force checkout (throw away local modifications)")),
1100 OPT_BOOL('m', "merge", &opts.merge, N_("perform a 3-way merge with the new branch")),
1101 OPT_BOOL(0, "overwrite-ignore", &opts.overwrite_ignore, N_("update ignored files (default)")),
1102 OPT_STRING(0, "conflict", &conflict_style, N_("style"),
1103 N_("conflict style (merge or diff3)")),
1104 OPT_BOOL('p', "patch", &opts.patch_mode, N_("select hunks interactively")),
1105 OPT_BOOL(0, "ignore-skip-worktree-bits", &opts.ignore_skipworktree,
1106 N_("do not limit pathspecs to sparse entries only")),
1107 OPT_HIDDEN_BOOL(0, "guess", &dwim_new_local_branch,
1108 N_("second guess 'git checkout no-such-branch'")),
1109 OPT_END(),
1112 memset(&opts, 0, sizeof(opts));
1113 memset(&new, 0, sizeof(new));
1114 opts.overwrite_ignore = 1;
1115 opts.prefix = prefix;
1117 gitmodules_config();
1118 git_config(git_checkout_config, &opts);
1120 opts.track = BRANCH_TRACK_UNSPECIFIED;
1122 argc = parse_options(argc, argv, prefix, options, checkout_usage,
1123 PARSE_OPT_KEEP_DASHDASH);
1125 if (conflict_style) {
1126 opts.merge = 1; /* implied */
1127 git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
1130 if ((!!opts.new_branch + !!opts.new_branch_force + !!opts.new_orphan_branch) > 1)
1131 die(_("-b, -B and --orphan are mutually exclusive"));
1134 * From here on, new_branch will contain the branch to be checked out,
1135 * and new_branch_force and new_orphan_branch will tell us which one of
1136 * -b/-B/--orphan is being used.
1138 if (opts.new_branch_force)
1139 opts.new_branch = opts.new_branch_force;
1141 if (opts.new_orphan_branch)
1142 opts.new_branch = opts.new_orphan_branch;
1144 /* --track without -b/-B/--orphan should DWIM */
1145 if (opts.track != BRANCH_TRACK_UNSPECIFIED && !opts.new_branch) {
1146 const char *argv0 = argv[0];
1147 if (!argc || !strcmp(argv0, "--"))
1148 die (_("--track needs a branch name"));
1149 if (starts_with(argv0, "refs/"))
1150 argv0 += 5;
1151 if (starts_with(argv0, "remotes/"))
1152 argv0 += 8;
1153 argv0 = strchr(argv0, '/');
1154 if (!argv0 || !argv0[1])
1155 die (_("Missing branch name; try -b"));
1156 opts.new_branch = argv0 + 1;
1160 * Extract branch name from command line arguments, so
1161 * all that is left is pathspecs.
1163 * Handle
1165 * 1) git checkout <tree> -- [<paths>]
1166 * 2) git checkout -- [<paths>]
1167 * 3) git checkout <something> [<paths>]
1169 * including "last branch" syntax and DWIM-ery for names of
1170 * remote branches, erroring out for invalid or ambiguous cases.
1172 if (argc) {
1173 unsigned char rev[20];
1174 int dwim_ok =
1175 !opts.patch_mode &&
1176 dwim_new_local_branch &&
1177 opts.track == BRANCH_TRACK_UNSPECIFIED &&
1178 !opts.new_branch;
1179 int n = parse_branchname_arg(argc, argv, dwim_ok,
1180 &new, &opts.source_tree,
1181 rev, &opts.new_branch);
1182 argv += n;
1183 argc -= n;
1186 if (argc) {
1187 parse_pathspec(&opts.pathspec, 0,
1188 opts.patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0,
1189 prefix, argv);
1191 if (!opts.pathspec.nr)
1192 die(_("invalid path specification"));
1195 * Try to give more helpful suggestion.
1196 * new_branch && argc > 1 will be caught later.
1198 if (opts.new_branch && argc == 1)
1199 die(_("Cannot update paths and switch to branch '%s' at the same time.\n"
1200 "Did you intend to checkout '%s' which can not be resolved as commit?"),
1201 opts.new_branch, argv[0]);
1203 if (opts.force_detach)
1204 die(_("git checkout: --detach does not take a path argument '%s'"),
1205 argv[0]);
1207 if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
1208 die(_("git checkout: --ours/--theirs, --force and --merge are incompatible when\n"
1209 "checking out of the index."));
1212 if (opts.new_branch) {
1213 struct strbuf buf = STRBUF_INIT;
1215 opts.branch_exists =
1216 validate_new_branchname(opts.new_branch, &buf,
1217 !!opts.new_branch_force,
1218 !!opts.new_branch_force);
1220 strbuf_release(&buf);
1223 if (opts.patch_mode || opts.pathspec.nr)
1224 return checkout_paths(&opts, new.name);
1225 else
1226 return checkout_branch(&opts, &new);