checkout: pass "struct checkout_opts *" as const pointer
[git/jnareb-git.git] / builtin / checkout.c
blob3e3f0865903f85cff7dc6ef7b691746570b47a6e
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 "git checkout [options] <branch>",
26 "git checkout [options] [<branch>] -- <file>...",
27 NULL,
30 struct checkout_opts {
31 int quiet;
32 int merge;
33 int force;
34 int force_detach;
35 int writeout_stage;
36 int overwrite_ignore;
38 /* not set by parse_options */
39 int branch_exists;
41 const char *new_branch;
42 const char *new_branch_force;
43 const char *new_orphan_branch;
44 int new_branch_log;
45 enum branch_track track;
46 struct diff_options diff_options;
49 static int post_checkout_hook(struct commit *old, struct commit *new,
50 int changed)
52 return run_hook(NULL, "post-checkout",
53 sha1_to_hex(old ? old->object.sha1 : null_sha1),
54 sha1_to_hex(new ? new->object.sha1 : null_sha1),
55 changed ? "1" : "0", NULL);
56 /* "new" can be NULL when checking out from the index before
57 a commit exists. */
61 static int update_some(const unsigned char *sha1, const char *base, int baselen,
62 const char *pathname, unsigned mode, int stage, void *context)
64 int len;
65 struct cache_entry *ce;
67 if (S_ISDIR(mode))
68 return READ_TREE_RECURSIVE;
70 len = baselen + strlen(pathname);
71 ce = xcalloc(1, cache_entry_size(len));
72 hashcpy(ce->sha1, sha1);
73 memcpy(ce->name, base, baselen);
74 memcpy(ce->name + baselen, pathname, len - baselen);
75 ce->ce_flags = create_ce_flags(0) | CE_UPDATE;
76 ce->ce_namelen = len;
77 ce->ce_mode = create_ce_mode(mode);
78 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
79 return 0;
82 static int read_tree_some(struct tree *tree, const char **pathspec)
84 struct pathspec ps;
85 init_pathspec(&ps, pathspec);
86 read_tree_recursive(tree, "", 0, 0, &ps, update_some, NULL);
87 free_pathspec(&ps);
89 /* update the index with the given tree's info
90 * for all args, expanding wildcards, and exit
91 * with any non-zero return code.
93 return 0;
96 static int skip_same_name(struct cache_entry *ce, int pos)
98 while (++pos < active_nr &&
99 !strcmp(active_cache[pos]->name, ce->name))
100 ; /* skip */
101 return pos;
104 static int check_stage(int stage, struct cache_entry *ce, int pos)
106 while (pos < active_nr &&
107 !strcmp(active_cache[pos]->name, ce->name)) {
108 if (ce_stage(active_cache[pos]) == stage)
109 return 0;
110 pos++;
112 if (stage == 2)
113 return error(_("path '%s' does not have our version"), ce->name);
114 else
115 return error(_("path '%s' does not have their version"), ce->name);
118 static int check_stages(unsigned stages, struct cache_entry *ce, int pos)
120 unsigned seen = 0;
121 const char *name = ce->name;
123 while (pos < active_nr) {
124 ce = active_cache[pos];
125 if (strcmp(name, ce->name))
126 break;
127 seen |= (1 << ce_stage(ce));
128 pos++;
130 if ((stages & seen) != stages)
131 return error(_("path '%s' does not have all necessary versions"),
132 name);
133 return 0;
136 static int checkout_stage(int stage, struct cache_entry *ce, int pos,
137 struct checkout *state)
139 while (pos < active_nr &&
140 !strcmp(active_cache[pos]->name, ce->name)) {
141 if (ce_stage(active_cache[pos]) == stage)
142 return checkout_entry(active_cache[pos], state, NULL);
143 pos++;
145 if (stage == 2)
146 return error(_("path '%s' does not have our version"), ce->name);
147 else
148 return error(_("path '%s' does not have their version"), ce->name);
151 static int checkout_merged(int pos, struct checkout *state)
153 struct cache_entry *ce = active_cache[pos];
154 const char *path = ce->name;
155 mmfile_t ancestor, ours, theirs;
156 int status;
157 unsigned char sha1[20];
158 mmbuffer_t result_buf;
159 unsigned char threeway[3][20];
160 unsigned mode = 0;
162 memset(threeway, 0, sizeof(threeway));
163 while (pos < active_nr) {
164 int stage;
165 stage = ce_stage(ce);
166 if (!stage || strcmp(path, ce->name))
167 break;
168 hashcpy(threeway[stage - 1], ce->sha1);
169 if (stage == 2)
170 mode = create_ce_mode(ce->ce_mode);
171 pos++;
172 ce = active_cache[pos];
174 if (is_null_sha1(threeway[1]) || is_null_sha1(threeway[2]))
175 return error(_("path '%s' does not have necessary versions"), path);
177 read_mmblob(&ancestor, threeway[0]);
178 read_mmblob(&ours, threeway[1]);
179 read_mmblob(&theirs, threeway[2]);
182 * NEEDSWORK: re-create conflicts from merges with
183 * merge.renormalize set, too
185 status = ll_merge(&result_buf, path, &ancestor, "base",
186 &ours, "ours", &theirs, "theirs", NULL);
187 free(ancestor.ptr);
188 free(ours.ptr);
189 free(theirs.ptr);
190 if (status < 0 || !result_buf.ptr) {
191 free(result_buf.ptr);
192 return error(_("path '%s': cannot merge"), path);
196 * NEEDSWORK:
197 * There is absolutely no reason to write this as a blob object
198 * and create a phony cache entry just to leak. This hack is
199 * primarily to get to the write_entry() machinery that massages
200 * the contents to work-tree format and writes out which only
201 * allows it for a cache entry. The code in write_entry() needs
202 * to be refactored to allow us to feed a <buffer, size, mode>
203 * instead of a cache entry. Such a refactoring would help
204 * merge_recursive as well (it also writes the merge result to the
205 * object database even when it may contain conflicts).
207 if (write_sha1_file(result_buf.ptr, result_buf.size,
208 blob_type, sha1))
209 die(_("Unable to add merge result for '%s'"), path);
210 ce = make_cache_entry(mode, sha1, path, 2, 0);
211 if (!ce)
212 die(_("make_cache_entry failed for path '%s'"), path);
213 status = checkout_entry(ce, state, NULL);
214 return status;
217 static int checkout_paths(struct tree *source_tree, const char **pathspec,
218 const char *prefix, const struct checkout_opts *opts)
220 int pos;
221 struct checkout state;
222 static char *ps_matched;
223 unsigned char rev[20];
224 int flag;
225 struct commit *head;
226 int errs = 0;
227 int stage = opts->writeout_stage;
228 int merge = opts->merge;
229 int newfd;
230 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
232 newfd = hold_locked_index(lock_file, 1);
233 if (read_cache_preload(pathspec) < 0)
234 return error(_("corrupt index file"));
236 if (source_tree)
237 read_tree_some(source_tree, pathspec);
239 for (pos = 0; pathspec[pos]; pos++)
241 ps_matched = xcalloc(1, pos);
243 for (pos = 0; pos < active_nr; pos++) {
244 struct cache_entry *ce = active_cache[pos];
245 if (source_tree && !(ce->ce_flags & CE_UPDATE))
246 continue;
247 match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, ps_matched);
250 if (report_path_error(ps_matched, pathspec, prefix))
251 return 1;
253 /* "checkout -m path" to recreate conflicted state */
254 if (opts->merge)
255 unmerge_cache(pathspec);
257 /* Any unmerged paths? */
258 for (pos = 0; pos < active_nr; pos++) {
259 struct cache_entry *ce = active_cache[pos];
260 if (match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, NULL)) {
261 if (!ce_stage(ce))
262 continue;
263 if (opts->force) {
264 warning(_("path '%s' is unmerged"), ce->name);
265 } else if (stage) {
266 errs |= check_stage(stage, ce, pos);
267 } else if (opts->merge) {
268 errs |= check_stages((1<<2) | (1<<3), ce, pos);
269 } else {
270 errs = 1;
271 error(_("path '%s' is unmerged"), ce->name);
273 pos = skip_same_name(ce, pos) - 1;
276 if (errs)
277 return 1;
279 /* Now we are committed to check them out */
280 memset(&state, 0, sizeof(state));
281 state.force = 1;
282 state.refresh_cache = 1;
283 for (pos = 0; pos < active_nr; pos++) {
284 struct cache_entry *ce = active_cache[pos];
285 if (source_tree && !(ce->ce_flags & CE_UPDATE))
286 continue;
287 if (match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, NULL)) {
288 if (!ce_stage(ce)) {
289 errs |= checkout_entry(ce, &state, NULL);
290 continue;
292 if (stage)
293 errs |= checkout_stage(stage, ce, pos, &state);
294 else if (merge)
295 errs |= checkout_merged(pos, &state);
296 pos = skip_same_name(ce, pos) - 1;
300 if (write_cache(newfd, active_cache, active_nr) ||
301 commit_locked_index(lock_file))
302 die(_("unable to write new index file"));
304 read_ref_full("HEAD", rev, 0, &flag);
305 head = lookup_commit_reference_gently(rev, 1);
307 errs |= post_checkout_hook(head, head, 0);
308 return errs;
311 static void show_local_changes(struct object *head,
312 const struct diff_options *opts)
314 struct rev_info rev;
315 /* I think we want full paths, even if we're in a subdirectory. */
316 init_revisions(&rev, NULL);
317 rev.diffopt.flags = opts->flags;
318 rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
319 diff_setup_done(&rev.diffopt);
320 add_pending_object(&rev, head, NULL);
321 run_diff_index(&rev, 0);
324 static void describe_detached_head(const char *msg, struct commit *commit)
326 struct strbuf sb = STRBUF_INIT;
327 parse_commit(commit);
328 pp_commit_easy(CMIT_FMT_ONELINE, commit, &sb);
329 fprintf(stderr, "%s %s... %s\n", msg,
330 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf);
331 strbuf_release(&sb);
334 static int reset_tree(struct tree *tree, const struct checkout_opts *o,
335 int worktree, int *writeout_error)
337 struct unpack_trees_options opts;
338 struct tree_desc tree_desc;
340 memset(&opts, 0, sizeof(opts));
341 opts.head_idx = -1;
342 opts.update = worktree;
343 opts.skip_unmerged = !worktree;
344 opts.reset = 1;
345 opts.merge = 1;
346 opts.fn = oneway_merge;
347 opts.verbose_update = !o->quiet && isatty(2);
348 opts.src_index = &the_index;
349 opts.dst_index = &the_index;
350 parse_tree(tree);
351 init_tree_desc(&tree_desc, tree->buffer, tree->size);
352 switch (unpack_trees(1, &tree_desc, &opts)) {
353 case -2:
354 *writeout_error = 1;
356 * We return 0 nevertheless, as the index is all right
357 * and more importantly we have made best efforts to
358 * update paths in the work tree, and we cannot revert
359 * them.
361 case 0:
362 return 0;
363 default:
364 return 128;
368 struct branch_info {
369 const char *name; /* The short name used */
370 const char *path; /* The full name of a real branch */
371 struct commit *commit; /* The named commit */
374 static void setup_branch_path(struct branch_info *branch)
376 struct strbuf buf = STRBUF_INIT;
378 strbuf_branchname(&buf, branch->name);
379 if (strcmp(buf.buf, branch->name))
380 branch->name = xstrdup(buf.buf);
381 strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
382 branch->path = strbuf_detach(&buf, NULL);
385 static int merge_working_tree(const struct checkout_opts *opts,
386 struct branch_info *old,
387 struct branch_info *new,
388 int *writeout_error)
390 int ret;
391 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
392 int newfd = hold_locked_index(lock_file, 1);
394 if (read_cache_preload(NULL) < 0)
395 return error(_("corrupt index file"));
397 resolve_undo_clear();
398 if (opts->force) {
399 ret = reset_tree(new->commit->tree, opts, 1, writeout_error);
400 if (ret)
401 return ret;
402 } else {
403 struct tree_desc trees[2];
404 struct tree *tree;
405 struct unpack_trees_options topts;
407 memset(&topts, 0, sizeof(topts));
408 topts.head_idx = -1;
409 topts.src_index = &the_index;
410 topts.dst_index = &the_index;
412 setup_unpack_trees_porcelain(&topts, "checkout");
414 refresh_cache(REFRESH_QUIET);
416 if (unmerged_cache()) {
417 error(_("you need to resolve your current index first"));
418 return 1;
421 /* 2-way merge to the new branch */
422 topts.initial_checkout = is_cache_unborn();
423 topts.update = 1;
424 topts.merge = 1;
425 topts.gently = opts->merge && old->commit;
426 topts.verbose_update = !opts->quiet && isatty(2);
427 topts.fn = twoway_merge;
428 if (opts->overwrite_ignore) {
429 topts.dir = xcalloc(1, sizeof(*topts.dir));
430 topts.dir->flags |= DIR_SHOW_IGNORED;
431 setup_standard_excludes(topts.dir);
433 tree = parse_tree_indirect(old->commit ?
434 old->commit->object.sha1 :
435 EMPTY_TREE_SHA1_BIN);
436 init_tree_desc(&trees[0], tree->buffer, tree->size);
437 tree = parse_tree_indirect(new->commit->object.sha1);
438 init_tree_desc(&trees[1], tree->buffer, tree->size);
440 ret = unpack_trees(2, trees, &topts);
441 if (ret == -1) {
443 * Unpack couldn't do a trivial merge; either
444 * give up or do a real merge, depending on
445 * whether the merge flag was used.
447 struct tree *result;
448 struct tree *work;
449 struct merge_options o;
450 if (!opts->merge)
451 return 1;
454 * Without old->commit, the below is the same as
455 * the two-tree unpack we already tried and failed.
457 if (!old->commit)
458 return 1;
460 /* Do more real merge */
463 * We update the index fully, then write the
464 * tree from the index, then merge the new
465 * branch with the current tree, with the old
466 * branch as the base. Then we reset the index
467 * (but not the working tree) to the new
468 * branch, leaving the working tree as the
469 * merged version, but skipping unmerged
470 * entries in the index.
473 add_files_to_cache(NULL, NULL, 0);
475 * NEEDSWORK: carrying over local changes
476 * when branches have different end-of-line
477 * normalization (or clean+smudge rules) is
478 * a pain; plumb in an option to set
479 * o.renormalize?
481 init_merge_options(&o);
482 o.verbosity = 0;
483 work = write_tree_from_memory(&o);
485 ret = reset_tree(new->commit->tree, opts, 1,
486 writeout_error);
487 if (ret)
488 return ret;
489 o.ancestor = old->name;
490 o.branch1 = new->name;
491 o.branch2 = "local";
492 merge_trees(&o, new->commit->tree, work,
493 old->commit->tree, &result);
494 ret = reset_tree(new->commit->tree, opts, 0,
495 writeout_error);
496 if (ret)
497 return ret;
501 if (write_cache(newfd, active_cache, active_nr) ||
502 commit_locked_index(lock_file))
503 die(_("unable to write new index file"));
505 if (!opts->force && !opts->quiet)
506 show_local_changes(&new->commit->object, &opts->diff_options);
508 return 0;
511 static void report_tracking(struct branch_info *new)
513 struct strbuf sb = STRBUF_INIT;
514 struct branch *branch = branch_get(new->name);
516 if (!format_tracking_info(branch, &sb))
517 return;
518 fputs(sb.buf, stdout);
519 strbuf_release(&sb);
522 static void update_refs_for_switch(const struct checkout_opts *opts,
523 struct branch_info *old,
524 struct branch_info *new)
526 struct strbuf msg = STRBUF_INIT;
527 const char *old_desc;
528 if (opts->new_branch) {
529 if (opts->new_orphan_branch) {
530 if (opts->new_branch_log && !log_all_ref_updates) {
531 int temp;
532 char log_file[PATH_MAX];
533 char *ref_name = mkpath("refs/heads/%s", opts->new_orphan_branch);
535 temp = log_all_ref_updates;
536 log_all_ref_updates = 1;
537 if (log_ref_setup(ref_name, log_file, sizeof(log_file))) {
538 fprintf(stderr, _("Can not do reflog for '%s'\n"),
539 opts->new_orphan_branch);
540 log_all_ref_updates = temp;
541 return;
543 log_all_ref_updates = temp;
546 else
547 create_branch(old->name, opts->new_branch, new->name,
548 opts->new_branch_force ? 1 : 0,
549 opts->new_branch_log,
550 opts->new_branch_force ? 1 : 0,
551 opts->quiet,
552 opts->track);
553 new->name = opts->new_branch;
554 setup_branch_path(new);
557 old_desc = old->name;
558 if (!old_desc && old->commit)
559 old_desc = sha1_to_hex(old->commit->object.sha1);
560 strbuf_addf(&msg, "checkout: moving from %s to %s",
561 old_desc ? old_desc : "(invalid)", new->name);
563 if (!strcmp(new->name, "HEAD") && !new->path && !opts->force_detach) {
564 /* Nothing to do. */
565 } else if (opts->force_detach || !new->path) { /* No longer on any branch. */
566 update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
567 REF_NODEREF, DIE_ON_ERR);
568 if (!opts->quiet) {
569 if (old->path && advice_detached_head)
570 detach_advice(new->name);
571 describe_detached_head(_("HEAD is now at"), new->commit);
573 } else if (new->path) { /* Switch branches. */
574 create_symref("HEAD", new->path, msg.buf);
575 if (!opts->quiet) {
576 if (old->path && !strcmp(new->path, old->path)) {
577 if (opts->new_branch_force)
578 fprintf(stderr, _("Reset branch '%s'\n"),
579 new->name);
580 else
581 fprintf(stderr, _("Already on '%s'\n"),
582 new->name);
583 } else if (opts->new_branch) {
584 if (opts->branch_exists)
585 fprintf(stderr, _("Switched to and reset branch '%s'\n"), new->name);
586 else
587 fprintf(stderr, _("Switched to a new branch '%s'\n"), new->name);
588 } else {
589 fprintf(stderr, _("Switched to branch '%s'\n"),
590 new->name);
593 if (old->path && old->name) {
594 char log_file[PATH_MAX], ref_file[PATH_MAX];
596 git_snpath(log_file, sizeof(log_file), "logs/%s", old->path);
597 git_snpath(ref_file, sizeof(ref_file), "%s", old->path);
598 if (!file_exists(ref_file) && file_exists(log_file))
599 remove_path(log_file);
602 remove_branch_state();
603 strbuf_release(&msg);
604 if (!opts->quiet &&
605 (new->path || (!opts->force_detach && !strcmp(new->name, "HEAD"))))
606 report_tracking(new);
609 static int add_pending_uninteresting_ref(const char *refname,
610 const unsigned char *sha1,
611 int flags, void *cb_data)
613 add_pending_sha1(cb_data, refname, sha1, UNINTERESTING);
614 return 0;
617 static void describe_one_orphan(struct strbuf *sb, struct commit *commit)
619 parse_commit(commit);
620 strbuf_addstr(sb, " ");
621 strbuf_addstr(sb,
622 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
623 strbuf_addch(sb, ' ');
624 pp_commit_easy(CMIT_FMT_ONELINE, commit, sb);
625 strbuf_addch(sb, '\n');
628 #define ORPHAN_CUTOFF 4
629 static void suggest_reattach(struct commit *commit, struct rev_info *revs)
631 struct commit *c, *last = NULL;
632 struct strbuf sb = STRBUF_INIT;
633 int lost = 0;
634 while ((c = get_revision(revs)) != NULL) {
635 if (lost < ORPHAN_CUTOFF)
636 describe_one_orphan(&sb, c);
637 last = c;
638 lost++;
640 if (ORPHAN_CUTOFF < lost) {
641 int more = lost - ORPHAN_CUTOFF;
642 if (more == 1)
643 describe_one_orphan(&sb, last);
644 else
645 strbuf_addf(&sb, _(" ... and %d more.\n"), more);
648 fprintf(stderr,
650 /* The singular version */
651 "Warning: you are leaving %d commit behind, "
652 "not connected to\n"
653 "any of your branches:\n\n"
654 "%s\n",
655 /* The plural version */
656 "Warning: you are leaving %d commits behind, "
657 "not connected to\n"
658 "any of your branches:\n\n"
659 "%s\n",
660 /* Give ngettext() the count */
661 lost),
662 lost,
663 sb.buf);
664 strbuf_release(&sb);
666 if (advice_detached_head)
667 fprintf(stderr,
669 "If you want to keep them by creating a new branch, "
670 "this may be a good time\nto do so with:\n\n"
671 " git branch new_branch_name %s\n\n"),
672 sha1_to_hex(commit->object.sha1));
676 * We are about to leave commit that was at the tip of a detached
677 * HEAD. If it is not reachable from any ref, this is the last chance
678 * for the user to do so without resorting to reflog.
680 static void orphaned_commit_warning(struct commit *old, struct commit *new)
682 struct rev_info revs;
683 struct object *object = &old->object;
684 struct object_array refs;
686 init_revisions(&revs, NULL);
687 setup_revisions(0, NULL, &revs, NULL);
689 object->flags &= ~UNINTERESTING;
690 add_pending_object(&revs, object, sha1_to_hex(object->sha1));
692 for_each_ref(add_pending_uninteresting_ref, &revs);
693 add_pending_sha1(&revs, "HEAD", new->object.sha1, UNINTERESTING);
695 refs = revs.pending;
696 revs.leak_pending = 1;
698 if (prepare_revision_walk(&revs))
699 die(_("internal error in revision walk"));
700 if (!(old->object.flags & UNINTERESTING))
701 suggest_reattach(old, &revs);
702 else
703 describe_detached_head(_("Previous HEAD position was"), old);
705 clear_commit_marks_for_object_array(&refs, ALL_REV_FLAGS);
706 free(refs.objects);
709 static int switch_branches(const struct checkout_opts *opts, struct branch_info *new)
711 int ret = 0;
712 struct branch_info old;
713 void *path_to_free;
714 unsigned char rev[20];
715 int flag, writeout_error = 0;
716 memset(&old, 0, sizeof(old));
717 old.path = path_to_free = resolve_refdup("HEAD", rev, 0, &flag);
718 old.commit = lookup_commit_reference_gently(rev, 1);
719 if (!(flag & REF_ISSYMREF))
720 old.path = NULL;
722 if (old.path && !prefixcmp(old.path, "refs/heads/"))
723 old.name = old.path + strlen("refs/heads/");
725 if (!new->name) {
726 new->name = "HEAD";
727 new->commit = old.commit;
728 if (!new->commit)
729 die(_("You are on a branch yet to be born"));
730 parse_commit(new->commit);
733 ret = merge_working_tree(opts, &old, new, &writeout_error);
734 if (ret) {
735 free(path_to_free);
736 return ret;
739 if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
740 orphaned_commit_warning(old.commit, new->commit);
742 update_refs_for_switch(opts, &old, new);
744 ret = post_checkout_hook(old.commit, new->commit, 1);
745 free(path_to_free);
746 return ret || writeout_error;
749 static int git_checkout_config(const char *var, const char *value, void *cb)
751 if (!strcmp(var, "diff.ignoresubmodules")) {
752 struct checkout_opts *opts = cb;
753 handle_ignore_submodules_arg(&opts->diff_options, value);
754 return 0;
757 if (!prefixcmp(var, "submodule."))
758 return parse_submodule_config_option(var, value);
760 return git_xmerge_config(var, value, NULL);
763 static int interactive_checkout(const char *revision, const char **pathspec,
764 struct checkout_opts *opts)
766 return run_add_interactive(revision, "--patch=checkout", pathspec);
769 struct tracking_name_data {
770 const char *name;
771 char *remote;
772 int unique;
775 static int check_tracking_name(const char *refname, const unsigned char *sha1,
776 int flags, void *cb_data)
778 struct tracking_name_data *cb = cb_data;
779 const char *slash;
781 if (prefixcmp(refname, "refs/remotes/"))
782 return 0;
783 slash = strchr(refname + 13, '/');
784 if (!slash || strcmp(slash + 1, cb->name))
785 return 0;
786 if (cb->remote) {
787 cb->unique = 0;
788 return 0;
790 cb->remote = xstrdup(refname);
791 return 0;
794 static const char *unique_tracking_name(const char *name)
796 struct tracking_name_data cb_data = { NULL, NULL, 1 };
797 cb_data.name = name;
798 for_each_ref(check_tracking_name, &cb_data);
799 if (cb_data.unique)
800 return cb_data.remote;
801 free(cb_data.remote);
802 return NULL;
805 static int parse_branchname_arg(int argc, const char **argv,
806 int dwim_new_local_branch_ok,
807 struct branch_info *new,
808 struct tree **source_tree,
809 unsigned char rev[20],
810 const char **new_branch)
812 int argcount = 0;
813 unsigned char branch_rev[20];
814 const char *arg;
815 int has_dash_dash;
818 * case 1: git checkout <ref> -- [<paths>]
820 * <ref> must be a valid tree, everything after the '--' must be
821 * a path.
823 * case 2: git checkout -- [<paths>]
825 * everything after the '--' must be paths.
827 * case 3: git checkout <something> [<paths>]
829 * With no paths, if <something> is a commit, that is to
830 * switch to the branch or detach HEAD at it. As a special case,
831 * if <something> is A...B (missing A or B means HEAD but you can
832 * omit at most one side), and if there is a unique merge base
833 * between A and B, A...B names that merge base.
835 * With no paths, if <something> is _not_ a commit, no -t nor -b
836 * was given, and there is a tracking branch whose name is
837 * <something> in one and only one remote, then this is a short-hand
838 * to fork local <something> from that remote-tracking branch.
840 * Otherwise <something> shall not be ambiguous.
841 * - If it's *only* a reference, treat it like case (1).
842 * - If it's only a path, treat it like case (2).
843 * - else: fail.
846 if (!argc)
847 return 0;
849 if (!strcmp(argv[0], "--")) /* case (2) */
850 return 1;
852 arg = argv[0];
853 has_dash_dash = (argc > 1) && !strcmp(argv[1], "--");
855 if (!strcmp(arg, "-"))
856 arg = "@{-1}";
858 if (get_sha1_mb(arg, rev)) {
859 if (has_dash_dash) /* case (1) */
860 die(_("invalid reference: %s"), arg);
861 if (dwim_new_local_branch_ok &&
862 !check_filename(NULL, arg) &&
863 argc == 1) {
864 const char *remote = unique_tracking_name(arg);
865 if (!remote || get_sha1(remote, rev))
866 return argcount;
867 *new_branch = arg;
868 arg = remote;
869 /* DWIMmed to create local branch */
870 } else {
871 return argcount;
875 /* we can't end up being in (2) anymore, eat the argument */
876 argcount++;
877 argv++;
878 argc--;
880 new->name = arg;
881 setup_branch_path(new);
883 if (!check_refname_format(new->path, 0) &&
884 !read_ref(new->path, branch_rev))
885 hashcpy(rev, branch_rev);
886 else
887 new->path = NULL; /* not an existing branch */
889 new->commit = lookup_commit_reference_gently(rev, 1);
890 if (!new->commit) {
891 /* not a commit */
892 *source_tree = parse_tree_indirect(rev);
893 } else {
894 parse_commit(new->commit);
895 *source_tree = new->commit->tree;
898 if (!*source_tree) /* case (1): want a tree */
899 die(_("reference is not a tree: %s"), arg);
900 if (!has_dash_dash) {/* case (3 -> 1) */
902 * Do not complain the most common case
903 * git checkout branch
904 * even if there happen to be a file called 'branch';
905 * it would be extremely annoying.
907 if (argc)
908 verify_non_filename(NULL, arg);
909 } else {
910 argcount++;
911 argv++;
912 argc--;
915 return argcount;
918 static int switch_unborn_to_new_branch(const struct checkout_opts *opts)
920 int status;
921 struct strbuf branch_ref = STRBUF_INIT;
923 if (!opts->new_branch)
924 die(_("You are on a branch yet to be born"));
925 strbuf_addf(&branch_ref, "refs/heads/%s", opts->new_branch);
926 status = create_symref("HEAD", branch_ref.buf, "checkout -b");
927 strbuf_release(&branch_ref);
928 return status;
931 int cmd_checkout(int argc, const char **argv, const char *prefix)
933 struct checkout_opts opts;
934 unsigned char rev[20];
935 struct branch_info new;
936 struct tree *source_tree = NULL;
937 char *conflict_style = NULL;
938 int patch_mode = 0;
939 int dwim_new_local_branch = 1;
940 struct option options[] = {
941 OPT__QUIET(&opts.quiet, "suppress progress reporting"),
942 OPT_STRING('b', NULL, &opts.new_branch, "branch",
943 "create and checkout a new branch"),
944 OPT_STRING('B', NULL, &opts.new_branch_force, "branch",
945 "create/reset and checkout a branch"),
946 OPT_BOOLEAN('l', NULL, &opts.new_branch_log, "create reflog for new branch"),
947 OPT_BOOLEAN(0, "detach", &opts.force_detach, "detach the HEAD at named commit"),
948 OPT_SET_INT('t', "track", &opts.track, "set upstream info for new branch",
949 BRANCH_TRACK_EXPLICIT),
950 OPT_STRING(0, "orphan", &opts.new_orphan_branch, "new branch", "new unparented branch"),
951 OPT_SET_INT('2', "ours", &opts.writeout_stage, "checkout our version for unmerged files",
953 OPT_SET_INT('3', "theirs", &opts.writeout_stage, "checkout their version for unmerged files",
955 OPT__FORCE(&opts.force, "force checkout (throw away local modifications)"),
956 OPT_BOOLEAN('m', "merge", &opts.merge, "perform a 3-way merge with the new branch"),
957 OPT_BOOLEAN(0, "overwrite-ignore", &opts.overwrite_ignore, "update ignored files (default)"),
958 OPT_STRING(0, "conflict", &conflict_style, "style",
959 "conflict style (merge or diff3)"),
960 OPT_BOOLEAN('p', "patch", &patch_mode, "select hunks interactively"),
961 { OPTION_BOOLEAN, 0, "guess", &dwim_new_local_branch, NULL,
962 "second guess 'git checkout no-such-branch'",
963 PARSE_OPT_NOARG | PARSE_OPT_HIDDEN },
964 OPT_END(),
967 memset(&opts, 0, sizeof(opts));
968 memset(&new, 0, sizeof(new));
969 opts.overwrite_ignore = 1;
971 gitmodules_config();
972 git_config(git_checkout_config, &opts);
974 opts.track = BRANCH_TRACK_UNSPECIFIED;
976 argc = parse_options(argc, argv, prefix, options, checkout_usage,
977 PARSE_OPT_KEEP_DASHDASH);
979 /* we can assume from now on new_branch = !new_branch_force */
980 if (opts.new_branch && opts.new_branch_force)
981 die(_("-B cannot be used with -b"));
983 /* copy -B over to -b, so that we can just check the latter */
984 if (opts.new_branch_force)
985 opts.new_branch = opts.new_branch_force;
987 if (patch_mode && (opts.track > 0 || opts.new_branch
988 || opts.new_branch_log || opts.merge || opts.force
989 || opts.force_detach))
990 die (_("--patch is incompatible with all other options"));
992 if (opts.force_detach && (opts.new_branch || opts.new_orphan_branch))
993 die(_("--detach cannot be used with -b/-B/--orphan"));
994 if (opts.force_detach && 0 < opts.track)
995 die(_("--detach cannot be used with -t"));
997 /* --track without -b should DWIM */
998 if (0 < opts.track && !opts.new_branch) {
999 const char *argv0 = argv[0];
1000 if (!argc || !strcmp(argv0, "--"))
1001 die (_("--track needs a branch name"));
1002 if (!prefixcmp(argv0, "refs/"))
1003 argv0 += 5;
1004 if (!prefixcmp(argv0, "remotes/"))
1005 argv0 += 8;
1006 argv0 = strchr(argv0, '/');
1007 if (!argv0 || !argv0[1])
1008 die (_("Missing branch name; try -b"));
1009 opts.new_branch = argv0 + 1;
1012 if (opts.new_orphan_branch) {
1013 if (opts.new_branch)
1014 die(_("--orphan and -b|-B are mutually exclusive"));
1015 if (opts.track > 0)
1016 die(_("--orphan cannot be used with -t"));
1017 opts.new_branch = opts.new_orphan_branch;
1020 if (conflict_style) {
1021 opts.merge = 1; /* implied */
1022 git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
1025 if (opts.force && opts.merge)
1026 die(_("git checkout: -f and -m are incompatible"));
1029 * Extract branch name from command line arguments, so
1030 * all that is left is pathspecs.
1032 * Handle
1034 * 1) git checkout <tree> -- [<paths>]
1035 * 2) git checkout -- [<paths>]
1036 * 3) git checkout <something> [<paths>]
1038 * including "last branch" syntax and DWIM-ery for names of
1039 * remote branches, erroring out for invalid or ambiguous cases.
1041 if (argc) {
1042 int dwim_ok =
1043 !patch_mode &&
1044 dwim_new_local_branch &&
1045 opts.track == BRANCH_TRACK_UNSPECIFIED &&
1046 !opts.new_branch;
1047 int n = parse_branchname_arg(argc, argv, dwim_ok,
1048 &new, &source_tree, rev, &opts.new_branch);
1049 argv += n;
1050 argc -= n;
1053 if (opts.track == BRANCH_TRACK_UNSPECIFIED)
1054 opts.track = git_branch_track;
1056 if (argc) {
1057 const char **pathspec = get_pathspec(prefix, argv);
1059 if (!pathspec)
1060 die(_("invalid path specification"));
1062 if (patch_mode)
1063 return interactive_checkout(new.name, pathspec, &opts);
1065 /* Checkout paths */
1066 if (opts.new_branch) {
1067 if (argc == 1) {
1068 die(_("git checkout: updating paths is incompatible with switching branches.\nDid you intend to checkout '%s' which can not be resolved as commit?"), argv[0]);
1069 } else {
1070 die(_("git checkout: updating paths is incompatible with switching branches."));
1074 if (opts.force_detach)
1075 die(_("git checkout: --detach does not take a path argument"));
1077 if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
1078 die(_("git checkout: --ours/--theirs, --force and --merge are incompatible when\nchecking out of the index."));
1080 return checkout_paths(source_tree, pathspec, prefix, &opts);
1083 if (patch_mode)
1084 return interactive_checkout(new.name, NULL, &opts);
1086 if (opts.new_branch) {
1087 struct strbuf buf = STRBUF_INIT;
1089 opts.branch_exists = validate_new_branchname(opts.new_branch, &buf,
1090 !!opts.new_branch_force,
1091 !!opts.new_branch_force);
1093 strbuf_release(&buf);
1096 if (new.name && !new.commit) {
1097 die(_("Cannot switch branch to a non-commit."));
1099 if (opts.writeout_stage)
1100 die(_("--ours/--theirs is incompatible with switching branches."));
1102 if (!new.commit && opts.new_branch) {
1103 unsigned char rev[20];
1104 int flag;
1106 if (!read_ref_full("HEAD", rev, 0, &flag) &&
1107 (flag & REF_ISSYMREF) && is_null_sha1(rev))
1108 return switch_unborn_to_new_branch(&opts);
1110 return switch_branches(&opts, &new);