merge-recursive: introduce merge_options
[git/git.git] / builtin-checkout.c
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 "unpack-trees.h"
9 #include "dir.h"
10 #include "run-command.h"
11 #include "merge-recursive.h"
12 #include "branch.h"
13 #include "diff.h"
14 #include "revision.h"
15 #include "remote.h"
16
17 static const char * const checkout_usage[] = {
18 "git checkout [options] <branch>",
19 "git checkout [options] [<branch>] -- <file>...",
20 NULL,
21 };
22
23 static int post_checkout_hook(struct commit *old, struct commit *new,
24 int changed)
25 {
26 struct child_process proc;
27 const char *name = git_path("hooks/post-checkout");
28 const char *argv[5];
29
30 if (access(name, X_OK) < 0)
31 return 0;
32
33 memset(&proc, 0, sizeof(proc));
34 argv[0] = name;
35 argv[1] = xstrdup(sha1_to_hex(old->object.sha1));
36 argv[2] = xstrdup(sha1_to_hex(new->object.sha1));
37 argv[3] = changed ? "1" : "0";
38 argv[4] = NULL;
39 proc.argv = argv;
40 proc.no_stdin = 1;
41 proc.stdout_to_stderr = 1;
42 return run_command(&proc);
43 }
44
45 static int update_some(const unsigned char *sha1, const char *base, int baselen,
46 const char *pathname, unsigned mode, int stage, void *context)
47 {
48 int len;
49 struct cache_entry *ce;
50
51 if (S_ISGITLINK(mode))
52 return 0;
53
54 if (S_ISDIR(mode))
55 return READ_TREE_RECURSIVE;
56
57 len = baselen + strlen(pathname);
58 ce = xcalloc(1, cache_entry_size(len));
59 hashcpy(ce->sha1, sha1);
60 memcpy(ce->name, base, baselen);
61 memcpy(ce->name + baselen, pathname, len - baselen);
62 ce->ce_flags = create_ce_flags(len, 0);
63 ce->ce_mode = create_ce_mode(mode);
64 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
65 return 0;
66 }
67
68 static int read_tree_some(struct tree *tree, const char **pathspec)
69 {
70 read_tree_recursive(tree, "", 0, 0, pathspec, update_some, NULL);
71
72 /* update the index with the given tree's info
73 * for all args, expanding wildcards, and exit
74 * with any non-zero return code.
75 */
76 return 0;
77 }
78
79 static int checkout_paths(struct tree *source_tree, const char **pathspec)
80 {
81 int pos;
82 struct checkout state;
83 static char *ps_matched;
84 unsigned char rev[20];
85 int flag;
86 struct commit *head;
87 int errs = 0;
88
89 int newfd;
90 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
91
92 newfd = hold_locked_index(lock_file, 1);
93 read_cache();
94
95 if (source_tree)
96 read_tree_some(source_tree, pathspec);
97
98 for (pos = 0; pathspec[pos]; pos++)
99 ;
100 ps_matched = xcalloc(1, pos);
101
102 for (pos = 0; pos < active_nr; pos++) {
103 struct cache_entry *ce = active_cache[pos];
104 pathspec_match(pathspec, ps_matched, ce->name, 0);
105 }
106
107 if (report_path_error(ps_matched, pathspec, 0))
108 return 1;
109
110 /* Now we are committed to check them out */
111 memset(&state, 0, sizeof(state));
112 state.force = 1;
113 state.refresh_cache = 1;
114 for (pos = 0; pos < active_nr; pos++) {
115 struct cache_entry *ce = active_cache[pos];
116 if (pathspec_match(pathspec, NULL, ce->name, 0)) {
117 errs |= checkout_entry(ce, &state, NULL);
118 }
119 }
120
121 if (write_cache(newfd, active_cache, active_nr) ||
122 commit_locked_index(lock_file))
123 die("unable to write new index file");
124
125 resolve_ref("HEAD", rev, 0, &flag);
126 head = lookup_commit_reference_gently(rev, 1);
127
128 errs |= post_checkout_hook(head, head, 0);
129 return errs;
130 }
131
132 static void show_local_changes(struct object *head)
133 {
134 struct rev_info rev;
135 /* I think we want full paths, even if we're in a subdirectory. */
136 init_revisions(&rev, NULL);
137 rev.abbrev = 0;
138 rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
139 add_pending_object(&rev, head, NULL);
140 run_diff_index(&rev, 0);
141 }
142
143 static void describe_detached_head(char *msg, struct commit *commit)
144 {
145 struct strbuf sb;
146 strbuf_init(&sb, 0);
147 parse_commit(commit);
148 pretty_print_commit(CMIT_FMT_ONELINE, commit, &sb, 0, NULL, NULL, 0, 0);
149 fprintf(stderr, "%s %s... %s\n", msg,
150 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf);
151 strbuf_release(&sb);
152 }
153
154 struct checkout_opts {
155 int quiet;
156 int merge;
157 int force;
158 int writeout_error;
159
160 const char *new_branch;
161 int new_branch_log;
162 enum branch_track track;
163 };
164
165 static int reset_tree(struct tree *tree, struct checkout_opts *o, int worktree)
166 {
167 struct unpack_trees_options opts;
168 struct tree_desc tree_desc;
169
170 memset(&opts, 0, sizeof(opts));
171 opts.head_idx = -1;
172 opts.update = worktree;
173 opts.skip_unmerged = !worktree;
174 opts.reset = 1;
175 opts.merge = 1;
176 opts.fn = oneway_merge;
177 opts.verbose_update = !o->quiet;
178 opts.src_index = &the_index;
179 opts.dst_index = &the_index;
180 parse_tree(tree);
181 init_tree_desc(&tree_desc, tree->buffer, tree->size);
182 switch (unpack_trees(1, &tree_desc, &opts)) {
183 case -2:
184 o->writeout_error = 1;
185 /*
186 * We return 0 nevertheless, as the index is all right
187 * and more importantly we have made best efforts to
188 * update paths in the work tree, and we cannot revert
189 * them.
190 */
191 case 0:
192 return 0;
193 default:
194 return 128;
195 }
196 }
197
198 struct branch_info {
199 const char *name; /* The short name used */
200 const char *path; /* The full name of a real branch */
201 struct commit *commit; /* The named commit */
202 };
203
204 static void setup_branch_path(struct branch_info *branch)
205 {
206 struct strbuf buf;
207 strbuf_init(&buf, 0);
208 strbuf_addstr(&buf, "refs/heads/");
209 strbuf_addstr(&buf, branch->name);
210 branch->path = strbuf_detach(&buf, NULL);
211 }
212
213 static int merge_working_tree(struct checkout_opts *opts,
214 struct branch_info *old, struct branch_info *new)
215 {
216 int ret;
217 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
218 int newfd = hold_locked_index(lock_file, 1);
219 read_cache();
220
221 if (opts->force) {
222 ret = reset_tree(new->commit->tree, opts, 1);
223 if (ret)
224 return ret;
225 } else {
226 struct tree_desc trees[2];
227 struct tree *tree;
228 struct unpack_trees_options topts;
229
230 memset(&topts, 0, sizeof(topts));
231 topts.head_idx = -1;
232 topts.src_index = &the_index;
233 topts.dst_index = &the_index;
234
235 topts.msgs.not_uptodate_file = "You have local changes to '%s'; cannot switch branches.";
236
237 refresh_cache(REFRESH_QUIET);
238
239 if (unmerged_cache()) {
240 error("you need to resolve your current index first");
241 return 1;
242 }
243
244 /* 2-way merge to the new branch */
245 topts.update = 1;
246 topts.merge = 1;
247 topts.gently = opts->merge;
248 topts.verbose_update = !opts->quiet;
249 topts.fn = twoway_merge;
250 topts.dir = xcalloc(1, sizeof(*topts.dir));
251 topts.dir->show_ignored = 1;
252 topts.dir->exclude_per_dir = ".gitignore";
253 tree = parse_tree_indirect(old->commit->object.sha1);
254 init_tree_desc(&trees[0], tree->buffer, tree->size);
255 tree = parse_tree_indirect(new->commit->object.sha1);
256 init_tree_desc(&trees[1], tree->buffer, tree->size);
257
258 ret = unpack_trees(2, trees, &topts);
259 if (ret == -1) {
260 /*
261 * Unpack couldn't do a trivial merge; either
262 * give up or do a real merge, depending on
263 * whether the merge flag was used.
264 */
265 struct tree *result;
266 struct tree *work;
267 struct merge_options o;
268 if (!opts->merge)
269 return 1;
270 parse_commit(old->commit);
271
272 /* Do more real merge */
273
274 /*
275 * We update the index fully, then write the
276 * tree from the index, then merge the new
277 * branch with the current tree, with the old
278 * branch as the base. Then we reset the index
279 * (but not the working tree) to the new
280 * branch, leaving the working tree as the
281 * merged version, but skipping unmerged
282 * entries in the index.
283 */
284
285 add_files_to_cache(NULL, NULL, 0);
286 init_merge_options(&o);
287 o.verbosity = 0;
288 work = write_tree_from_memory(&o);
289
290 ret = reset_tree(new->commit->tree, opts, 1);
291 if (ret)
292 return ret;
293 o.branch1 = new->name;
294 o.branch2 = "local";
295 merge_trees(&o, new->commit->tree, work,
296 old->commit->tree, &result);
297 ret = reset_tree(new->commit->tree, opts, 0);
298 if (ret)
299 return ret;
300 }
301 }
302
303 if (write_cache(newfd, active_cache, active_nr) ||
304 commit_locked_index(lock_file))
305 die("unable to write new index file");
306
307 if (!opts->force)
308 show_local_changes(&new->commit->object);
309
310 return 0;
311 }
312
313 static void report_tracking(struct branch_info *new)
314 {
315 struct strbuf sb = STRBUF_INIT;
316 struct branch *branch = branch_get(new->name);
317
318 if (!format_tracking_info(branch, &sb))
319 return;
320 fputs(sb.buf, stdout);
321 strbuf_release(&sb);
322 }
323
324 static void update_refs_for_switch(struct checkout_opts *opts,
325 struct branch_info *old,
326 struct branch_info *new)
327 {
328 struct strbuf msg;
329 const char *old_desc;
330 if (opts->new_branch) {
331 create_branch(old->name, opts->new_branch, new->name, 0,
332 opts->new_branch_log, opts->track);
333 new->name = opts->new_branch;
334 setup_branch_path(new);
335 }
336
337 strbuf_init(&msg, 0);
338 old_desc = old->name;
339 if (!old_desc)
340 old_desc = sha1_to_hex(old->commit->object.sha1);
341 strbuf_addf(&msg, "checkout: moving from %s to %s",
342 old_desc, new->name);
343
344 if (new->path) {
345 create_symref("HEAD", new->path, msg.buf);
346 if (!opts->quiet) {
347 if (old->path && !strcmp(new->path, old->path))
348 fprintf(stderr, "Already on \"%s\"\n",
349 new->name);
350 else
351 fprintf(stderr, "Switched to%s branch \"%s\"\n",
352 opts->new_branch ? " a new" : "",
353 new->name);
354 }
355 } else if (strcmp(new->name, "HEAD")) {
356 update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
357 REF_NODEREF, DIE_ON_ERR);
358 if (!opts->quiet) {
359 if (old->path)
360 fprintf(stderr, "Note: moving to \"%s\" which isn't a local branch\nIf you want to create a new branch from this checkout, you may do so\n(now or later) by using -b with the checkout command again. Example:\n git checkout -b <new_branch_name>\n", new->name);
361 describe_detached_head("HEAD is now at", new->commit);
362 }
363 }
364 remove_branch_state();
365 strbuf_release(&msg);
366 if (!opts->quiet && (new->path || !strcmp(new->name, "HEAD")))
367 report_tracking(new);
368 }
369
370 static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
371 {
372 int ret = 0;
373 struct branch_info old;
374 unsigned char rev[20];
375 int flag;
376 memset(&old, 0, sizeof(old));
377 old.path = resolve_ref("HEAD", rev, 0, &flag);
378 old.commit = lookup_commit_reference_gently(rev, 1);
379 if (!(flag & REF_ISSYMREF))
380 old.path = NULL;
381
382 if (old.path && !prefixcmp(old.path, "refs/heads/"))
383 old.name = old.path + strlen("refs/heads/");
384
385 if (!new->name) {
386 new->name = "HEAD";
387 new->commit = old.commit;
388 if (!new->commit)
389 die("You are on a branch yet to be born");
390 parse_commit(new->commit);
391 }
392
393 /*
394 * If the new thing isn't a branch and isn't HEAD and we're
395 * not starting a new branch, and we want messages, and we
396 * weren't on a branch, and we're moving to a new commit,
397 * describe the old commit.
398 */
399 if (!new->path && strcmp(new->name, "HEAD") && !opts->new_branch &&
400 !opts->quiet && !old.path && new->commit != old.commit)
401 describe_detached_head("Previous HEAD position was", old.commit);
402
403 if (!old.commit) {
404 if (!opts->quiet) {
405 fprintf(stderr, "warning: You appear to be on a branch yet to be born.\n");
406 fprintf(stderr, "warning: Forcing checkout of %s.\n", new->name);
407 }
408 opts->force = 1;
409 }
410
411 ret = merge_working_tree(opts, &old, new);
412 if (ret)
413 return ret;
414
415 update_refs_for_switch(opts, &old, new);
416
417 ret = post_checkout_hook(old.commit, new->commit, 1);
418 return ret || opts->writeout_error;
419 }
420
421 int cmd_checkout(int argc, const char **argv, const char *prefix)
422 {
423 struct checkout_opts opts;
424 unsigned char rev[20];
425 const char *arg;
426 struct branch_info new;
427 struct tree *source_tree = NULL;
428 struct option options[] = {
429 OPT__QUIET(&opts.quiet),
430 OPT_STRING('b', NULL, &opts.new_branch, "new branch", "branch"),
431 OPT_BOOLEAN('l', NULL, &opts.new_branch_log, "log for new branch"),
432 OPT_SET_INT('t', "track", &opts.track, "track",
433 BRANCH_TRACK_EXPLICIT),
434 OPT_BOOLEAN('f', NULL, &opts.force, "force"),
435 OPT_BOOLEAN('m', NULL, &opts.merge, "merge"),
436 OPT_END(),
437 };
438 int has_dash_dash;
439
440 memset(&opts, 0, sizeof(opts));
441 memset(&new, 0, sizeof(new));
442
443 git_config(git_default_config, NULL);
444
445 opts.track = BRANCH_TRACK_UNSPECIFIED;
446
447 argc = parse_options(argc, argv, options, checkout_usage,
448 PARSE_OPT_KEEP_DASHDASH);
449
450 /* --track without -b should DWIM */
451 if (0 < opts.track && !opts.new_branch) {
452 const char *argv0 = argv[0];
453 if (!argc || !strcmp(argv0, "--"))
454 die ("--track needs a branch name");
455 if (!prefixcmp(argv0, "refs/"))
456 argv0 += 5;
457 if (!prefixcmp(argv0, "remotes/"))
458 argv0 += 8;
459 argv0 = strchr(argv0, '/');
460 if (!argv0 || !argv0[1])
461 die ("Missing branch name; try -b");
462 opts.new_branch = argv0 + 1;
463 }
464
465 if (opts.track == BRANCH_TRACK_UNSPECIFIED)
466 opts.track = git_branch_track;
467
468 if (opts.force && opts.merge)
469 die("git checkout: -f and -m are incompatible");
470
471 /*
472 * case 1: git checkout <ref> -- [<paths>]
473 *
474 * <ref> must be a valid tree, everything after the '--' must be
475 * a path.
476 *
477 * case 2: git checkout -- [<paths>]
478 *
479 * everything after the '--' must be paths.
480 *
481 * case 3: git checkout <something> [<paths>]
482 *
483 * With no paths, if <something> is a commit, that is to
484 * switch to the branch or detach HEAD at it.
485 *
486 * Otherwise <something> shall not be ambiguous.
487 * - If it's *only* a reference, treat it like case (1).
488 * - If it's only a path, treat it like case (2).
489 * - else: fail.
490 *
491 */
492 if (argc) {
493 if (!strcmp(argv[0], "--")) { /* case (2) */
494 argv++;
495 argc--;
496 goto no_reference;
497 }
498
499 arg = argv[0];
500 has_dash_dash = (argc > 1) && !strcmp(argv[1], "--");
501
502 if (get_sha1(arg, rev)) {
503 if (has_dash_dash) /* case (1) */
504 die("invalid reference: %s", arg);
505 goto no_reference; /* case (3 -> 2) */
506 }
507
508 /* we can't end up being in (2) anymore, eat the argument */
509 argv++;
510 argc--;
511
512 if ((new.commit = lookup_commit_reference_gently(rev, 1))) {
513 new.name = arg;
514 setup_branch_path(&new);
515 if (resolve_ref(new.path, rev, 1, NULL))
516 new.commit = lookup_commit_reference(rev);
517 else
518 new.path = NULL;
519 parse_commit(new.commit);
520 source_tree = new.commit->tree;
521 } else
522 source_tree = parse_tree_indirect(rev);
523
524 if (!source_tree) /* case (1): want a tree */
525 die("reference is not a tree: %s", arg);
526 if (!has_dash_dash) {/* case (3 -> 1) */
527 /*
528 * Do not complain the most common case
529 * git checkout branch
530 * even if there happen to be a file called 'branch';
531 * it would be extremely annoying.
532 */
533 if (argc)
534 verify_non_filename(NULL, arg);
535 }
536 else {
537 argv++;
538 argc--;
539 }
540 }
541
542 no_reference:
543 if (argc) {
544 const char **pathspec = get_pathspec(prefix, argv);
545
546 if (!pathspec)
547 die("invalid path specification");
548
549 /* Checkout paths */
550 if (opts.new_branch || opts.force || opts.merge) {
551 if (argc == 1) {
552 die("git checkout: updating paths is incompatible with switching branches/forcing\nDid you intend to checkout '%s' which can not be resolved as commit?", argv[0]);
553 } else {
554 die("git checkout: updating paths is incompatible with switching branches/forcing");
555 }
556 }
557
558 return checkout_paths(source_tree, pathspec);
559 }
560
561 if (new.name && !new.commit) {
562 die("Cannot switch branch to a non-commit.");
563 }
564
565 return switch_branches(&opts, &new);
566 }