userdiff: add built-in pattern for golang
[git/git.git] / builtin / checkout.c
1 #include "builtin.h"
2 #include "config.h"
3 #include "checkout.h"
4 #include "lockfile.h"
5 #include "parse-options.h"
6 #include "refs.h"
7 #include "commit.h"
8 #include "tree.h"
9 #include "tree-walk.h"
10 #include "cache-tree.h"
11 #include "unpack-trees.h"
12 #include "dir.h"
13 #include "run-command.h"
14 #include "merge-recursive.h"
15 #include "branch.h"
16 #include "diff.h"
17 #include "revision.h"
18 #include "remote.h"
19 #include "blob.h"
20 #include "xdiff-interface.h"
21 #include "ll-merge.h"
22 #include "resolve-undo.h"
23 #include "submodule-config.h"
24 #include "submodule.h"
25
26 static const char * const checkout_usage[] = {
27 N_("git checkout [<options>] <branch>"),
28 N_("git checkout [<options>] [<branch>] -- <file>..."),
29 NULL,
30 };
31
32 struct checkout_opts {
33 int patch_mode;
34 int quiet;
35 int merge;
36 int force;
37 int force_detach;
38 int writeout_stage;
39 int overwrite_ignore;
40 int ignore_skipworktree;
41 int ignore_other_worktrees;
42 int show_progress;
43
44 const char *new_branch;
45 const char *new_branch_force;
46 const char *new_orphan_branch;
47 int new_branch_log;
48 enum branch_track track;
49 struct diff_options diff_options;
50
51 int branch_exists;
52 const char *prefix;
53 struct pathspec pathspec;
54 struct tree *source_tree;
55 };
56
57 static int post_checkout_hook(struct commit *old, struct commit *new,
58 int changed)
59 {
60 return run_hook_le(NULL, "post-checkout",
61 oid_to_hex(old ? &old->object.oid : &null_oid),
62 oid_to_hex(new ? &new->object.oid : &null_oid),
63 changed ? "1" : "0", NULL);
64 /* "new" can be NULL when checking out from the index before
65 a commit exists. */
66
67 }
68
69 static int update_some(const unsigned char *sha1, struct strbuf *base,
70 const char *pathname, unsigned mode, int stage, void *context)
71 {
72 int len;
73 struct cache_entry *ce;
74 int pos;
75
76 if (S_ISDIR(mode))
77 return READ_TREE_RECURSIVE;
78
79 len = base->len + strlen(pathname);
80 ce = xcalloc(1, cache_entry_size(len));
81 hashcpy(ce->oid.hash, sha1);
82 memcpy(ce->name, base->buf, base->len);
83 memcpy(ce->name + base->len, pathname, len - base->len);
84 ce->ce_flags = create_ce_flags(0) | CE_UPDATE;
85 ce->ce_namelen = len;
86 ce->ce_mode = create_ce_mode(mode);
87
88 /*
89 * If the entry is the same as the current index, we can leave the old
90 * entry in place. Whether it is UPTODATE or not, checkout_entry will
91 * do the right thing.
92 */
93 pos = cache_name_pos(ce->name, ce->ce_namelen);
94 if (pos >= 0) {
95 struct cache_entry *old = active_cache[pos];
96 if (ce->ce_mode == old->ce_mode &&
97 !oidcmp(&ce->oid, &old->oid)) {
98 old->ce_flags |= CE_UPDATE;
99 free(ce);
100 return 0;
101 }
102 }
103
104 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
105 return 0;
106 }
107
108 static int read_tree_some(struct tree *tree, const struct pathspec *pathspec)
109 {
110 read_tree_recursive(tree, "", 0, 0, pathspec, update_some, NULL);
111
112 /* update the index with the given tree's info
113 * for all args, expanding wildcards, and exit
114 * with any non-zero return code.
115 */
116 return 0;
117 }
118
119 static int skip_same_name(const struct cache_entry *ce, int pos)
120 {
121 while (++pos < active_nr &&
122 !strcmp(active_cache[pos]->name, ce->name))
123 ; /* skip */
124 return pos;
125 }
126
127 static int check_stage(int stage, const struct cache_entry *ce, int pos)
128 {
129 while (pos < active_nr &&
130 !strcmp(active_cache[pos]->name, ce->name)) {
131 if (ce_stage(active_cache[pos]) == stage)
132 return 0;
133 pos++;
134 }
135 if (stage == 2)
136 return error(_("path '%s' does not have our version"), ce->name);
137 else
138 return error(_("path '%s' does not have their version"), ce->name);
139 }
140
141 static int check_stages(unsigned stages, const struct cache_entry *ce, int pos)
142 {
143 unsigned seen = 0;
144 const char *name = ce->name;
145
146 while (pos < active_nr) {
147 ce = active_cache[pos];
148 if (strcmp(name, ce->name))
149 break;
150 seen |= (1 << ce_stage(ce));
151 pos++;
152 }
153 if ((stages & seen) != stages)
154 return error(_("path '%s' does not have all necessary versions"),
155 name);
156 return 0;
157 }
158
159 static int checkout_stage(int stage, const struct cache_entry *ce, int pos,
160 const struct checkout *state)
161 {
162 while (pos < active_nr &&
163 !strcmp(active_cache[pos]->name, ce->name)) {
164 if (ce_stage(active_cache[pos]) == stage)
165 return checkout_entry(active_cache[pos], state, NULL);
166 pos++;
167 }
168 if (stage == 2)
169 return error(_("path '%s' does not have our version"), ce->name);
170 else
171 return error(_("path '%s' does not have their version"), ce->name);
172 }
173
174 static int checkout_merged(int pos, const struct checkout *state)
175 {
176 struct cache_entry *ce = active_cache[pos];
177 const char *path = ce->name;
178 mmfile_t ancestor, ours, theirs;
179 int status;
180 struct object_id oid;
181 mmbuffer_t result_buf;
182 struct object_id threeway[3];
183 unsigned mode = 0;
184
185 memset(threeway, 0, sizeof(threeway));
186 while (pos < active_nr) {
187 int stage;
188 stage = ce_stage(ce);
189 if (!stage || strcmp(path, ce->name))
190 break;
191 oidcpy(&threeway[stage - 1], &ce->oid);
192 if (stage == 2)
193 mode = create_ce_mode(ce->ce_mode);
194 pos++;
195 ce = active_cache[pos];
196 }
197 if (is_null_oid(&threeway[1]) || is_null_oid(&threeway[2]))
198 return error(_("path '%s' does not have necessary versions"), path);
199
200 read_mmblob(&ancestor, &threeway[0]);
201 read_mmblob(&ours, &threeway[1]);
202 read_mmblob(&theirs, &threeway[2]);
203
204 /*
205 * NEEDSWORK: re-create conflicts from merges with
206 * merge.renormalize set, too
207 */
208 status = ll_merge(&result_buf, path, &ancestor, "base",
209 &ours, "ours", &theirs, "theirs", NULL);
210 free(ancestor.ptr);
211 free(ours.ptr);
212 free(theirs.ptr);
213 if (status < 0 || !result_buf.ptr) {
214 free(result_buf.ptr);
215 return error(_("path '%s': cannot merge"), path);
216 }
217
218 /*
219 * NEEDSWORK:
220 * There is absolutely no reason to write this as a blob object
221 * and create a phony cache entry. This hack is primarily to get
222 * to the write_entry() machinery that massages the contents to
223 * work-tree format and writes out which only allows it for a
224 * cache entry. The code in write_entry() needs to be refactored
225 * to allow us to feed a <buffer, size, mode> instead of a cache
226 * entry. Such a refactoring would help merge_recursive as well
227 * (it also writes the merge result to the object database even
228 * when it may contain conflicts).
229 */
230 if (write_object_file(result_buf.ptr, result_buf.size, blob_type, &oid))
231 die(_("Unable to add merge result for '%s'"), path);
232 free(result_buf.ptr);
233 ce = make_cache_entry(mode, oid.hash, path, 2, 0);
234 if (!ce)
235 die(_("make_cache_entry failed for path '%s'"), path);
236 status = checkout_entry(ce, state, NULL);
237 free(ce);
238 return status;
239 }
240
241 static int checkout_paths(const struct checkout_opts *opts,
242 const char *revision)
243 {
244 int pos;
245 struct checkout state = CHECKOUT_INIT;
246 static char *ps_matched;
247 struct object_id rev;
248 struct commit *head;
249 int errs = 0;
250 struct lock_file lock_file = LOCK_INIT;
251
252 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
253 die(_("'%s' cannot be used with updating paths"), "--track");
254
255 if (opts->new_branch_log)
256 die(_("'%s' cannot be used with updating paths"), "-l");
257
258 if (opts->force && opts->patch_mode)
259 die(_("'%s' cannot be used with updating paths"), "-f");
260
261 if (opts->force_detach)
262 die(_("'%s' cannot be used with updating paths"), "--detach");
263
264 if (opts->merge && opts->patch_mode)
265 die(_("'%s' cannot be used with %s"), "--merge", "--patch");
266
267 if (opts->force && opts->merge)
268 die(_("'%s' cannot be used with %s"), "-f", "-m");
269
270 if (opts->new_branch)
271 die(_("Cannot update paths and switch to branch '%s' at the same time."),
272 opts->new_branch);
273
274 if (opts->patch_mode)
275 return run_add_interactive(revision, "--patch=checkout",
276 &opts->pathspec);
277
278 hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
279 if (read_cache_preload(&opts->pathspec) < 0)
280 return error(_("index file corrupt"));
281
282 if (opts->source_tree)
283 read_tree_some(opts->source_tree, &opts->pathspec);
284
285 ps_matched = xcalloc(opts->pathspec.nr, 1);
286
287 /*
288 * Make sure all pathspecs participated in locating the paths
289 * to be checked out.
290 */
291 for (pos = 0; pos < active_nr; pos++) {
292 struct cache_entry *ce = active_cache[pos];
293 ce->ce_flags &= ~CE_MATCHED;
294 if (!opts->ignore_skipworktree && ce_skip_worktree(ce))
295 continue;
296 if (opts->source_tree && !(ce->ce_flags & CE_UPDATE))
297 /*
298 * "git checkout tree-ish -- path", but this entry
299 * is in the original index; it will not be checked
300 * out to the working tree and it does not matter
301 * if pathspec matched this entry. We will not do
302 * anything to this entry at all.
303 */
304 continue;
305 /*
306 * Either this entry came from the tree-ish we are
307 * checking the paths out of, or we are checking out
308 * of the index.
309 *
310 * If it comes from the tree-ish, we already know it
311 * matches the pathspec and could just stamp
312 * CE_MATCHED to it from update_some(). But we still
313 * need ps_matched and read_tree_recursive (and
314 * eventually tree_entry_interesting) cannot fill
315 * ps_matched yet. Once it can, we can avoid calling
316 * match_pathspec() for _all_ entries when
317 * opts->source_tree != NULL.
318 */
319 if (ce_path_match(ce, &opts->pathspec, ps_matched))
320 ce->ce_flags |= CE_MATCHED;
321 }
322
323 if (report_path_error(ps_matched, &opts->pathspec, opts->prefix)) {
324 free(ps_matched);
325 return 1;
326 }
327 free(ps_matched);
328
329 /* "checkout -m path" to recreate conflicted state */
330 if (opts->merge)
331 unmerge_marked_index(&the_index);
332
333 /* Any unmerged paths? */
334 for (pos = 0; pos < active_nr; pos++) {
335 const struct cache_entry *ce = active_cache[pos];
336 if (ce->ce_flags & CE_MATCHED) {
337 if (!ce_stage(ce))
338 continue;
339 if (opts->force) {
340 warning(_("path '%s' is unmerged"), ce->name);
341 } else if (opts->writeout_stage) {
342 errs |= check_stage(opts->writeout_stage, ce, pos);
343 } else if (opts->merge) {
344 errs |= check_stages((1<<2) | (1<<3), ce, pos);
345 } else {
346 errs = 1;
347 error(_("path '%s' is unmerged"), ce->name);
348 }
349 pos = skip_same_name(ce, pos) - 1;
350 }
351 }
352 if (errs)
353 return 1;
354
355 /* Now we are committed to check them out */
356 state.force = 1;
357 state.refresh_cache = 1;
358 state.istate = &the_index;
359
360 enable_delayed_checkout(&state);
361 for (pos = 0; pos < active_nr; pos++) {
362 struct cache_entry *ce = active_cache[pos];
363 if (ce->ce_flags & CE_MATCHED) {
364 if (!ce_stage(ce)) {
365 errs |= checkout_entry(ce, &state, NULL);
366 continue;
367 }
368 if (opts->writeout_stage)
369 errs |= checkout_stage(opts->writeout_stage, ce, pos, &state);
370 else if (opts->merge)
371 errs |= checkout_merged(pos, &state);
372 pos = skip_same_name(ce, pos) - 1;
373 }
374 }
375 errs |= finish_delayed_checkout(&state);
376
377 if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
378 die(_("unable to write new index file"));
379
380 read_ref_full("HEAD", 0, &rev, NULL);
381 head = lookup_commit_reference_gently(&rev, 1);
382
383 errs |= post_checkout_hook(head, head, 0);
384 return errs;
385 }
386
387 static void show_local_changes(struct object *head,
388 const struct diff_options *opts)
389 {
390 struct rev_info rev;
391 /* I think we want full paths, even if we're in a subdirectory. */
392 init_revisions(&rev, NULL);
393 rev.diffopt.flags = opts->flags;
394 rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
395 diff_setup_done(&rev.diffopt);
396 add_pending_object(&rev, head, NULL);
397 run_diff_index(&rev, 0);
398 }
399
400 static void describe_detached_head(const char *msg, struct commit *commit)
401 {
402 struct strbuf sb = STRBUF_INIT;
403
404 if (!parse_commit(commit))
405 pp_commit_easy(CMIT_FMT_ONELINE, commit, &sb);
406 if (print_sha1_ellipsis()) {
407 fprintf(stderr, "%s %s... %s\n", msg,
408 find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV), sb.buf);
409 } else {
410 fprintf(stderr, "%s %s %s\n", msg,
411 find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV), sb.buf);
412 }
413 strbuf_release(&sb);
414 }
415
416 static int reset_tree(struct tree *tree, const struct checkout_opts *o,
417 int worktree, int *writeout_error)
418 {
419 struct unpack_trees_options opts;
420 struct tree_desc tree_desc;
421
422 memset(&opts, 0, sizeof(opts));
423 opts.head_idx = -1;
424 opts.update = worktree;
425 opts.skip_unmerged = !worktree;
426 opts.reset = 1;
427 opts.merge = 1;
428 opts.fn = oneway_merge;
429 opts.verbose_update = o->show_progress;
430 opts.src_index = &the_index;
431 opts.dst_index = &the_index;
432 parse_tree(tree);
433 init_tree_desc(&tree_desc, tree->buffer, tree->size);
434 switch (unpack_trees(1, &tree_desc, &opts)) {
435 case -2:
436 *writeout_error = 1;
437 /*
438 * We return 0 nevertheless, as the index is all right
439 * and more importantly we have made best efforts to
440 * update paths in the work tree, and we cannot revert
441 * them.
442 */
443 /* fallthrough */
444 case 0:
445 return 0;
446 default:
447 return 128;
448 }
449 }
450
451 struct branch_info {
452 const char *name; /* The short name used */
453 const char *path; /* The full name of a real branch */
454 struct commit *commit; /* The named commit */
455 /*
456 * if not null the branch is detached because it's already
457 * checked out in this checkout
458 */
459 char *checkout;
460 };
461
462 static void setup_branch_path(struct branch_info *branch)
463 {
464 struct strbuf buf = STRBUF_INIT;
465
466 strbuf_branchname(&buf, branch->name, INTERPRET_BRANCH_LOCAL);
467 if (strcmp(buf.buf, branch->name))
468 branch->name = xstrdup(buf.buf);
469 strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
470 branch->path = strbuf_detach(&buf, NULL);
471 }
472
473 static int merge_working_tree(const struct checkout_opts *opts,
474 struct branch_info *old,
475 struct branch_info *new,
476 int *writeout_error)
477 {
478 int ret;
479 struct lock_file lock_file = LOCK_INIT;
480
481 hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
482 if (read_cache_preload(NULL) < 0)
483 return error(_("index file corrupt"));
484
485 resolve_undo_clear();
486 if (opts->force) {
487 ret = reset_tree(new->commit->tree, opts, 1, writeout_error);
488 if (ret)
489 return ret;
490 } else {
491 struct tree_desc trees[2];
492 struct tree *tree;
493 struct unpack_trees_options topts;
494
495 memset(&topts, 0, sizeof(topts));
496 topts.head_idx = -1;
497 topts.src_index = &the_index;
498 topts.dst_index = &the_index;
499
500 setup_unpack_trees_porcelain(&topts, "checkout");
501
502 refresh_cache(REFRESH_QUIET);
503
504 if (unmerged_cache()) {
505 error(_("you need to resolve your current index first"));
506 return 1;
507 }
508
509 /* 2-way merge to the new branch */
510 topts.initial_checkout = is_cache_unborn();
511 topts.update = 1;
512 topts.merge = 1;
513 topts.gently = opts->merge && old->commit;
514 topts.verbose_update = opts->show_progress;
515 topts.fn = twoway_merge;
516 if (opts->overwrite_ignore) {
517 topts.dir = xcalloc(1, sizeof(*topts.dir));
518 topts.dir->flags |= DIR_SHOW_IGNORED;
519 setup_standard_excludes(topts.dir);
520 }
521 tree = parse_tree_indirect(old->commit ?
522 &old->commit->object.oid :
523 the_hash_algo->empty_tree);
524 init_tree_desc(&trees[0], tree->buffer, tree->size);
525 tree = parse_tree_indirect(&new->commit->object.oid);
526 init_tree_desc(&trees[1], tree->buffer, tree->size);
527
528 ret = unpack_trees(2, trees, &topts);
529 if (ret == -1) {
530 /*
531 * Unpack couldn't do a trivial merge; either
532 * give up or do a real merge, depending on
533 * whether the merge flag was used.
534 */
535 struct tree *result;
536 struct tree *work;
537 struct merge_options o;
538 if (!opts->merge)
539 return 1;
540
541 /*
542 * Without old->commit, the below is the same as
543 * the two-tree unpack we already tried and failed.
544 */
545 if (!old->commit)
546 return 1;
547
548 /* Do more real merge */
549
550 /*
551 * We update the index fully, then write the
552 * tree from the index, then merge the new
553 * branch with the current tree, with the old
554 * branch as the base. Then we reset the index
555 * (but not the working tree) to the new
556 * branch, leaving the working tree as the
557 * merged version, but skipping unmerged
558 * entries in the index.
559 */
560
561 add_files_to_cache(NULL, NULL, 0);
562 /*
563 * NEEDSWORK: carrying over local changes
564 * when branches have different end-of-line
565 * normalization (or clean+smudge rules) is
566 * a pain; plumb in an option to set
567 * o.renormalize?
568 */
569 init_merge_options(&o);
570 o.verbosity = 0;
571 work = write_tree_from_memory(&o);
572
573 ret = reset_tree(new->commit->tree, opts, 1,
574 writeout_error);
575 if (ret)
576 return ret;
577 o.ancestor = old->name;
578 o.branch1 = new->name;
579 o.branch2 = "local";
580 ret = merge_trees(&o, new->commit->tree, work,
581 old->commit->tree, &result);
582 if (ret < 0)
583 exit(128);
584 ret = reset_tree(new->commit->tree, opts, 0,
585 writeout_error);
586 strbuf_release(&o.obuf);
587 if (ret)
588 return ret;
589 }
590 }
591
592 if (!active_cache_tree)
593 active_cache_tree = cache_tree();
594
595 if (!cache_tree_fully_valid(active_cache_tree))
596 cache_tree_update(&the_index, WRITE_TREE_SILENT | WRITE_TREE_REPAIR);
597
598 if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
599 die(_("unable to write new index file"));
600
601 if (!opts->force && !opts->quiet)
602 show_local_changes(&new->commit->object, &opts->diff_options);
603
604 return 0;
605 }
606
607 static void report_tracking(struct branch_info *new)
608 {
609 struct strbuf sb = STRBUF_INIT;
610 struct branch *branch = branch_get(new->name);
611
612 if (!format_tracking_info(branch, &sb))
613 return;
614 fputs(sb.buf, stdout);
615 strbuf_release(&sb);
616 }
617
618 static void update_refs_for_switch(const struct checkout_opts *opts,
619 struct branch_info *old,
620 struct branch_info *new)
621 {
622 struct strbuf msg = STRBUF_INIT;
623 const char *old_desc, *reflog_msg;
624 if (opts->new_branch) {
625 if (opts->new_orphan_branch) {
626 char *refname;
627
628 refname = mkpathdup("refs/heads/%s", opts->new_orphan_branch);
629 if (opts->new_branch_log &&
630 !should_autocreate_reflog(refname)) {
631 int ret;
632 struct strbuf err = STRBUF_INIT;
633
634 ret = safe_create_reflog(refname, 1, &err);
635 if (ret) {
636 fprintf(stderr, _("Can not do reflog for '%s': %s\n"),
637 opts->new_orphan_branch, err.buf);
638 strbuf_release(&err);
639 free(refname);
640 return;
641 }
642 strbuf_release(&err);
643 }
644 free(refname);
645 }
646 else
647 create_branch(opts->new_branch, new->name,
648 opts->new_branch_force ? 1 : 0,
649 opts->new_branch_force ? 1 : 0,
650 opts->new_branch_log,
651 opts->quiet,
652 opts->track);
653 new->name = opts->new_branch;
654 setup_branch_path(new);
655 }
656
657 old_desc = old->name;
658 if (!old_desc && old->commit)
659 old_desc = oid_to_hex(&old->commit->object.oid);
660
661 reflog_msg = getenv("GIT_REFLOG_ACTION");
662 if (!reflog_msg)
663 strbuf_addf(&msg, "checkout: moving from %s to %s",
664 old_desc ? old_desc : "(invalid)", new->name);
665 else
666 strbuf_insert(&msg, 0, reflog_msg, strlen(reflog_msg));
667
668 if (!strcmp(new->name, "HEAD") && !new->path && !opts->force_detach) {
669 /* Nothing to do. */
670 } else if (opts->force_detach || !new->path) { /* No longer on any branch. */
671 update_ref(msg.buf, "HEAD", &new->commit->object.oid, NULL,
672 REF_NO_DEREF, UPDATE_REFS_DIE_ON_ERR);
673 if (!opts->quiet) {
674 if (old->path &&
675 advice_detached_head && !opts->force_detach)
676 detach_advice(new->name);
677 describe_detached_head(_("HEAD is now at"), new->commit);
678 }
679 } else if (new->path) { /* Switch branches. */
680 if (create_symref("HEAD", new->path, msg.buf) < 0)
681 die(_("unable to update HEAD"));
682 if (!opts->quiet) {
683 if (old->path && !strcmp(new->path, old->path)) {
684 if (opts->new_branch_force)
685 fprintf(stderr, _("Reset branch '%s'\n"),
686 new->name);
687 else
688 fprintf(stderr, _("Already on '%s'\n"),
689 new->name);
690 } else if (opts->new_branch) {
691 if (opts->branch_exists)
692 fprintf(stderr, _("Switched to and reset branch '%s'\n"), new->name);
693 else
694 fprintf(stderr, _("Switched to a new branch '%s'\n"), new->name);
695 } else {
696 fprintf(stderr, _("Switched to branch '%s'\n"),
697 new->name);
698 }
699 }
700 if (old->path && old->name) {
701 if (!ref_exists(old->path) && reflog_exists(old->path))
702 delete_reflog(old->path);
703 }
704 }
705 remove_branch_state();
706 strbuf_release(&msg);
707 if (!opts->quiet &&
708 (new->path || (!opts->force_detach && !strcmp(new->name, "HEAD"))))
709 report_tracking(new);
710 }
711
712 static int add_pending_uninteresting_ref(const char *refname,
713 const struct object_id *oid,
714 int flags, void *cb_data)
715 {
716 add_pending_oid(cb_data, refname, oid, UNINTERESTING);
717 return 0;
718 }
719
720 static void describe_one_orphan(struct strbuf *sb, struct commit *commit)
721 {
722 strbuf_addstr(sb, " ");
723 strbuf_add_unique_abbrev(sb, commit->object.oid.hash, DEFAULT_ABBREV);
724 strbuf_addch(sb, ' ');
725 if (!parse_commit(commit))
726 pp_commit_easy(CMIT_FMT_ONELINE, commit, sb);
727 strbuf_addch(sb, '\n');
728 }
729
730 #define ORPHAN_CUTOFF 4
731 static void suggest_reattach(struct commit *commit, struct rev_info *revs)
732 {
733 struct commit *c, *last = NULL;
734 struct strbuf sb = STRBUF_INIT;
735 int lost = 0;
736 while ((c = get_revision(revs)) != NULL) {
737 if (lost < ORPHAN_CUTOFF)
738 describe_one_orphan(&sb, c);
739 last = c;
740 lost++;
741 }
742 if (ORPHAN_CUTOFF < lost) {
743 int more = lost - ORPHAN_CUTOFF;
744 if (more == 1)
745 describe_one_orphan(&sb, last);
746 else
747 strbuf_addf(&sb, _(" ... and %d more.\n"), more);
748 }
749
750 fprintf(stderr,
751 Q_(
752 /* The singular version */
753 "Warning: you are leaving %d commit behind, "
754 "not connected to\n"
755 "any of your branches:\n\n"
756 "%s\n",
757 /* The plural version */
758 "Warning: you are leaving %d commits behind, "
759 "not connected to\n"
760 "any of your branches:\n\n"
761 "%s\n",
762 /* Give ngettext() the count */
763 lost),
764 lost,
765 sb.buf);
766 strbuf_release(&sb);
767
768 if (advice_detached_head)
769 fprintf(stderr,
770 Q_(
771 /* The singular version */
772 "If you want to keep it by creating a new branch, "
773 "this may be a good time\nto do so with:\n\n"
774 " git branch <new-branch-name> %s\n\n",
775 /* The plural version */
776 "If you want to keep them by creating a new branch, "
777 "this may be a good time\nto do so with:\n\n"
778 " git branch <new-branch-name> %s\n\n",
779 /* Give ngettext() the count */
780 lost),
781 find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV));
782 }
783
784 /*
785 * We are about to leave commit that was at the tip of a detached
786 * HEAD. If it is not reachable from any ref, this is the last chance
787 * for the user to do so without resorting to reflog.
788 */
789 static void orphaned_commit_warning(struct commit *old, struct commit *new)
790 {
791 struct rev_info revs;
792 struct object *object = &old->object;
793
794 init_revisions(&revs, NULL);
795 setup_revisions(0, NULL, &revs, NULL);
796
797 object->flags &= ~UNINTERESTING;
798 add_pending_object(&revs, object, oid_to_hex(&object->oid));
799
800 for_each_ref(add_pending_uninteresting_ref, &revs);
801 add_pending_oid(&revs, "HEAD", &new->object.oid, UNINTERESTING);
802
803 if (prepare_revision_walk(&revs))
804 die(_("internal error in revision walk"));
805 if (!(old->object.flags & UNINTERESTING))
806 suggest_reattach(old, &revs);
807 else
808 describe_detached_head(_("Previous HEAD position was"), old);
809
810 /* Clean up objects used, as they will be reused. */
811 clear_commit_marks_all(ALL_REV_FLAGS);
812 }
813
814 static int switch_branches(const struct checkout_opts *opts,
815 struct branch_info *new)
816 {
817 int ret = 0;
818 struct branch_info old;
819 void *path_to_free;
820 struct object_id rev;
821 int flag, writeout_error = 0;
822 memset(&old, 0, sizeof(old));
823 old.path = path_to_free = resolve_refdup("HEAD", 0, &rev, &flag);
824 if (old.path)
825 old.commit = lookup_commit_reference_gently(&rev, 1);
826 if (!(flag & REF_ISSYMREF))
827 old.path = NULL;
828
829 if (old.path)
830 skip_prefix(old.path, "refs/heads/", &old.name);
831
832 if (!new->name) {
833 new->name = "HEAD";
834 new->commit = old.commit;
835 if (!new->commit)
836 die(_("You are on a branch yet to be born"));
837 parse_commit_or_die(new->commit);
838 }
839
840 ret = merge_working_tree(opts, &old, new, &writeout_error);
841 if (ret) {
842 free(path_to_free);
843 return ret;
844 }
845
846 if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
847 orphaned_commit_warning(old.commit, new->commit);
848
849 update_refs_for_switch(opts, &old, new);
850
851 ret = post_checkout_hook(old.commit, new->commit, 1);
852 free(path_to_free);
853 return ret || writeout_error;
854 }
855
856 static int git_checkout_config(const char *var, const char *value, void *cb)
857 {
858 if (!strcmp(var, "diff.ignoresubmodules")) {
859 struct checkout_opts *opts = cb;
860 handle_ignore_submodules_arg(&opts->diff_options, value);
861 return 0;
862 }
863
864 if (starts_with(var, "submodule."))
865 return git_default_submodule_config(var, value, NULL);
866
867 return git_xmerge_config(var, value, NULL);
868 }
869
870 static int parse_branchname_arg(int argc, const char **argv,
871 int dwim_new_local_branch_ok,
872 struct branch_info *new,
873 struct checkout_opts *opts,
874 struct object_id *rev)
875 {
876 struct tree **source_tree = &opts->source_tree;
877 const char **new_branch = &opts->new_branch;
878 int argcount = 0;
879 struct object_id branch_rev;
880 const char *arg;
881 int dash_dash_pos;
882 int has_dash_dash = 0;
883 int i;
884
885 /*
886 * case 1: git checkout <ref> -- [<paths>]
887 *
888 * <ref> must be a valid tree, everything after the '--' must be
889 * a path.
890 *
891 * case 2: git checkout -- [<paths>]
892 *
893 * everything after the '--' must be paths.
894 *
895 * case 3: git checkout <something> [--]
896 *
897 * (a) If <something> is a commit, that is to
898 * switch to the branch or detach HEAD at it. As a special case,
899 * if <something> is A...B (missing A or B means HEAD but you can
900 * omit at most one side), and if there is a unique merge base
901 * between A and B, A...B names that merge base.
902 *
903 * (b) If <something> is _not_ a commit, either "--" is present
904 * or <something> is not a path, no -t or -b was given, and
905 * and there is a tracking branch whose name is <something>
906 * in one and only one remote, then this is a short-hand to
907 * fork local <something> from that remote-tracking branch.
908 *
909 * (c) Otherwise, if "--" is present, treat it like case (1).
910 *
911 * (d) Otherwise :
912 * - if it's a reference, treat it like case (1)
913 * - else if it's a path, treat it like case (2)
914 * - else: fail.
915 *
916 * case 4: git checkout <something> <paths>
917 *
918 * The first argument must not be ambiguous.
919 * - If it's *only* a reference, treat it like case (1).
920 * - If it's only a path, treat it like case (2).
921 * - else: fail.
922 *
923 */
924 if (!argc)
925 return 0;
926
927 arg = argv[0];
928 dash_dash_pos = -1;
929 for (i = 0; i < argc; i++) {
930 if (!strcmp(argv[i], "--")) {
931 dash_dash_pos = i;
932 break;
933 }
934 }
935 if (dash_dash_pos == 0)
936 return 1; /* case (2) */
937 else if (dash_dash_pos == 1)
938 has_dash_dash = 1; /* case (3) or (1) */
939 else if (dash_dash_pos >= 2)
940 die(_("only one reference expected, %d given."), dash_dash_pos);
941
942 if (!strcmp(arg, "-"))
943 arg = "@{-1}";
944
945 if (get_oid_mb(arg, rev)) {
946 /*
947 * Either case (3) or (4), with <something> not being
948 * a commit, or an attempt to use case (1) with an
949 * invalid ref.
950 *
951 * It's likely an error, but we need to find out if
952 * we should auto-create the branch, case (3).(b).
953 */
954 int recover_with_dwim = dwim_new_local_branch_ok;
955
956 if (!has_dash_dash &&
957 (check_filename(opts->prefix, arg) || !no_wildcard(arg)))
958 recover_with_dwim = 0;
959 /*
960 * Accept "git checkout foo" and "git checkout foo --"
961 * as candidates for dwim.
962 */
963 if (!(argc == 1 && !has_dash_dash) &&
964 !(argc == 2 && has_dash_dash))
965 recover_with_dwim = 0;
966
967 if (recover_with_dwim) {
968 const char *remote = unique_tracking_name(arg, rev);
969 if (remote) {
970 *new_branch = arg;
971 arg = remote;
972 /* DWIMmed to create local branch, case (3).(b) */
973 } else {
974 recover_with_dwim = 0;
975 }
976 }
977
978 if (!recover_with_dwim) {
979 if (has_dash_dash)
980 die(_("invalid reference: %s"), arg);
981 return argcount;
982 }
983 }
984
985 /* we can't end up being in (2) anymore, eat the argument */
986 argcount++;
987 argv++;
988 argc--;
989
990 new->name = arg;
991 setup_branch_path(new);
992
993 if (!check_refname_format(new->path, 0) &&
994 !read_ref(new->path, &branch_rev))
995 oidcpy(rev, &branch_rev);
996 else
997 new->path = NULL; /* not an existing branch */
998
999 new->commit = lookup_commit_reference_gently(rev, 1);
1000 if (!new->commit) {
1001 /* not a commit */
1002 *source_tree = parse_tree_indirect(rev);
1003 } else {
1004 parse_commit_or_die(new->commit);
1005 *source_tree = new->commit->tree;
1006 }
1007
1008 if (!*source_tree) /* case (1): want a tree */
1009 die(_("reference is not a tree: %s"), arg);
1010 if (!has_dash_dash) { /* case (3).(d) -> (1) */
1011 /*
1012 * Do not complain the most common case
1013 * git checkout branch
1014 * even if there happen to be a file called 'branch';
1015 * it would be extremely annoying.
1016 */
1017 if (argc)
1018 verify_non_filename(opts->prefix, arg);
1019 } else {
1020 argcount++;
1021 argv++;
1022 argc--;
1023 }
1024
1025 return argcount;
1026 }
1027
1028 static int switch_unborn_to_new_branch(const struct checkout_opts *opts)
1029 {
1030 int status;
1031 struct strbuf branch_ref = STRBUF_INIT;
1032
1033 if (!opts->new_branch)
1034 die(_("You are on a branch yet to be born"));
1035 strbuf_addf(&branch_ref, "refs/heads/%s", opts->new_branch);
1036 status = create_symref("HEAD", branch_ref.buf, "checkout -b");
1037 strbuf_release(&branch_ref);
1038 if (!opts->quiet)
1039 fprintf(stderr, _("Switched to a new branch '%s'\n"),
1040 opts->new_branch);
1041 return status;
1042 }
1043
1044 static int checkout_branch(struct checkout_opts *opts,
1045 struct branch_info *new)
1046 {
1047 if (opts->pathspec.nr)
1048 die(_("paths cannot be used with switching branches"));
1049
1050 if (opts->patch_mode)
1051 die(_("'%s' cannot be used with switching branches"),
1052 "--patch");
1053
1054 if (opts->writeout_stage)
1055 die(_("'%s' cannot be used with switching branches"),
1056 "--ours/--theirs");
1057
1058 if (opts->force && opts->merge)
1059 die(_("'%s' cannot be used with '%s'"), "-f", "-m");
1060
1061 if (opts->force_detach && opts->new_branch)
1062 die(_("'%s' cannot be used with '%s'"),
1063 "--detach", "-b/-B/--orphan");
1064
1065 if (opts->new_orphan_branch) {
1066 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1067 die(_("'%s' cannot be used with '%s'"), "--orphan", "-t");
1068 } else if (opts->force_detach) {
1069 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1070 die(_("'%s' cannot be used with '%s'"), "--detach", "-t");
1071 } else if (opts->track == BRANCH_TRACK_UNSPECIFIED)
1072 opts->track = git_branch_track;
1073
1074 if (new->name && !new->commit)
1075 die(_("Cannot switch branch to a non-commit '%s'"),
1076 new->name);
1077
1078 if (new->path && !opts->force_detach && !opts->new_branch &&
1079 !opts->ignore_other_worktrees) {
1080 int flag;
1081 char *head_ref = resolve_refdup("HEAD", 0, NULL, &flag);
1082 if (head_ref &&
1083 (!(flag & REF_ISSYMREF) || strcmp(head_ref, new->path)))
1084 die_if_checked_out(new->path, 1);
1085 free(head_ref);
1086 }
1087
1088 if (!new->commit && opts->new_branch) {
1089 struct object_id rev;
1090 int flag;
1091
1092 if (!read_ref_full("HEAD", 0, &rev, &flag) &&
1093 (flag & REF_ISSYMREF) && is_null_oid(&rev))
1094 return switch_unborn_to_new_branch(opts);
1095 }
1096 return switch_branches(opts, new);
1097 }
1098
1099 int cmd_checkout(int argc, const char **argv, const char *prefix)
1100 {
1101 struct checkout_opts opts;
1102 struct branch_info new;
1103 char *conflict_style = NULL;
1104 int dwim_new_local_branch = 1;
1105 struct option options[] = {
1106 OPT__QUIET(&opts.quiet, N_("suppress progress reporting")),
1107 OPT_STRING('b', NULL, &opts.new_branch, N_("branch"),
1108 N_("create and checkout a new branch")),
1109 OPT_STRING('B', NULL, &opts.new_branch_force, N_("branch"),
1110 N_("create/reset and checkout a branch")),
1111 OPT_BOOL('l', NULL, &opts.new_branch_log, N_("create reflog for new branch")),
1112 OPT_BOOL(0, "detach", &opts.force_detach, N_("detach HEAD at named commit")),
1113 OPT_SET_INT('t', "track", &opts.track, N_("set upstream info for new branch"),
1114 BRANCH_TRACK_EXPLICIT),
1115 OPT_STRING(0, "orphan", &opts.new_orphan_branch, N_("new-branch"), N_("new unparented branch")),
1116 OPT_SET_INT('2', "ours", &opts.writeout_stage, N_("checkout our version for unmerged files"),
1117 2),
1118 OPT_SET_INT('3', "theirs", &opts.writeout_stage, N_("checkout their version for unmerged files"),
1119 3),
1120 OPT__FORCE(&opts.force, N_("force checkout (throw away local modifications)")),
1121 OPT_BOOL('m', "merge", &opts.merge, N_("perform a 3-way merge with the new branch")),
1122 OPT_BOOL(0, "overwrite-ignore", &opts.overwrite_ignore, N_("update ignored files (default)")),
1123 OPT_STRING(0, "conflict", &conflict_style, N_("style"),
1124 N_("conflict style (merge or diff3)")),
1125 OPT_BOOL('p', "patch", &opts.patch_mode, N_("select hunks interactively")),
1126 OPT_BOOL(0, "ignore-skip-worktree-bits", &opts.ignore_skipworktree,
1127 N_("do not limit pathspecs to sparse entries only")),
1128 OPT_HIDDEN_BOOL(0, "guess", &dwim_new_local_branch,
1129 N_("second guess 'git checkout <no-such-branch>'")),
1130 OPT_BOOL(0, "ignore-other-worktrees", &opts.ignore_other_worktrees,
1131 N_("do not check if another worktree is holding the given ref")),
1132 { OPTION_CALLBACK, 0, "recurse-submodules", NULL,
1133 "checkout", "control recursive updating of submodules",
1134 PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater },
1135 OPT_BOOL(0, "progress", &opts.show_progress, N_("force progress reporting")),
1136 OPT_END(),
1137 };
1138
1139 memset(&opts, 0, sizeof(opts));
1140 memset(&new, 0, sizeof(new));
1141 opts.overwrite_ignore = 1;
1142 opts.prefix = prefix;
1143 opts.show_progress = -1;
1144
1145 git_config(git_checkout_config, &opts);
1146
1147 opts.track = BRANCH_TRACK_UNSPECIFIED;
1148
1149 argc = parse_options(argc, argv, prefix, options, checkout_usage,
1150 PARSE_OPT_KEEP_DASHDASH);
1151
1152 if (opts.show_progress < 0) {
1153 if (opts.quiet)
1154 opts.show_progress = 0;
1155 else
1156 opts.show_progress = isatty(2);
1157 }
1158
1159 if (conflict_style) {
1160 opts.merge = 1; /* implied */
1161 git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
1162 }
1163
1164 if ((!!opts.new_branch + !!opts.new_branch_force + !!opts.new_orphan_branch) > 1)
1165 die(_("-b, -B and --orphan are mutually exclusive"));
1166
1167 /*
1168 * From here on, new_branch will contain the branch to be checked out,
1169 * and new_branch_force and new_orphan_branch will tell us which one of
1170 * -b/-B/--orphan is being used.
1171 */
1172 if (opts.new_branch_force)
1173 opts.new_branch = opts.new_branch_force;
1174
1175 if (opts.new_orphan_branch)
1176 opts.new_branch = opts.new_orphan_branch;
1177
1178 /* --track without -b/-B/--orphan should DWIM */
1179 if (opts.track != BRANCH_TRACK_UNSPECIFIED && !opts.new_branch) {
1180 const char *argv0 = argv[0];
1181 if (!argc || !strcmp(argv0, "--"))
1182 die (_("--track needs a branch name"));
1183 skip_prefix(argv0, "refs/", &argv0);
1184 skip_prefix(argv0, "remotes/", &argv0);
1185 argv0 = strchr(argv0, '/');
1186 if (!argv0 || !argv0[1])
1187 die (_("Missing branch name; try -b"));
1188 opts.new_branch = argv0 + 1;
1189 }
1190
1191 /*
1192 * Extract branch name from command line arguments, so
1193 * all that is left is pathspecs.
1194 *
1195 * Handle
1196 *
1197 * 1) git checkout <tree> -- [<paths>]
1198 * 2) git checkout -- [<paths>]
1199 * 3) git checkout <something> [<paths>]
1200 *
1201 * including "last branch" syntax and DWIM-ery for names of
1202 * remote branches, erroring out for invalid or ambiguous cases.
1203 */
1204 if (argc) {
1205 struct object_id rev;
1206 int dwim_ok =
1207 !opts.patch_mode &&
1208 dwim_new_local_branch &&
1209 opts.track == BRANCH_TRACK_UNSPECIFIED &&
1210 !opts.new_branch;
1211 int n = parse_branchname_arg(argc, argv, dwim_ok,
1212 &new, &opts, &rev);
1213 argv += n;
1214 argc -= n;
1215 }
1216
1217 if (argc) {
1218 parse_pathspec(&opts.pathspec, 0,
1219 opts.patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0,
1220 prefix, argv);
1221
1222 if (!opts.pathspec.nr)
1223 die(_("invalid path specification"));
1224
1225 /*
1226 * Try to give more helpful suggestion.
1227 * new_branch && argc > 1 will be caught later.
1228 */
1229 if (opts.new_branch && argc == 1)
1230 die(_("'%s' is not a commit and a branch '%s' cannot be created from it"),
1231 argv[0], opts.new_branch);
1232
1233 if (opts.force_detach)
1234 die(_("git checkout: --detach does not take a path argument '%s'"),
1235 argv[0]);
1236
1237 if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
1238 die(_("git checkout: --ours/--theirs, --force and --merge are incompatible when\n"
1239 "checking out of the index."));
1240 }
1241
1242 if (opts.new_branch) {
1243 struct strbuf buf = STRBUF_INIT;
1244
1245 if (opts.new_branch_force)
1246 opts.branch_exists = validate_branchname(opts.new_branch, &buf);
1247 else
1248 opts.branch_exists =
1249 validate_new_branchname(opts.new_branch, &buf, 0);
1250 strbuf_release(&buf);
1251 }
1252
1253 UNLEAK(opts);
1254 if (opts.patch_mode || opts.pathspec.nr)
1255 return checkout_paths(&opts, new.name);
1256 else
1257 return checkout_branch(&opts, &new);
1258 }