Provide git_config with a callback-data parameter
[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)
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);
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
88 int newfd;
89 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
90
91 newfd = hold_locked_index(lock_file, 1);
92 read_cache();
93
94 if (source_tree)
95 read_tree_some(source_tree, pathspec);
96
97 for (pos = 0; pathspec[pos]; pos++)
98 ;
99 ps_matched = xcalloc(1, pos);
100
101 for (pos = 0; pos < active_nr; pos++) {
102 struct cache_entry *ce = active_cache[pos];
103 pathspec_match(pathspec, ps_matched, ce->name, 0);
104 }
105
106 if (report_path_error(ps_matched, pathspec, 0))
107 return 1;
108
109 memset(&state, 0, sizeof(state));
110 state.force = 1;
111 state.refresh_cache = 1;
112 for (pos = 0; pos < active_nr; pos++) {
113 struct cache_entry *ce = active_cache[pos];
114 if (pathspec_match(pathspec, NULL, ce->name, 0)) {
115 checkout_entry(ce, &state, NULL);
116 }
117 }
118
119 if (write_cache(newfd, active_cache, active_nr) ||
120 commit_locked_index(lock_file))
121 die("unable to write new index file");
122
123 resolve_ref("HEAD", rev, 0, &flag);
124 head = lookup_commit_reference_gently(rev, 1);
125
126 return post_checkout_hook(head, head, 0);
127 }
128
129 static void show_local_changes(struct object *head)
130 {
131 struct rev_info rev;
132 /* I think we want full paths, even if we're in a subdirectory. */
133 init_revisions(&rev, NULL);
134 rev.abbrev = 0;
135 rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
136 add_pending_object(&rev, head, NULL);
137 run_diff_index(&rev, 0);
138 }
139
140 static void describe_detached_head(char *msg, struct commit *commit)
141 {
142 struct strbuf sb;
143 strbuf_init(&sb, 0);
144 parse_commit(commit);
145 pretty_print_commit(CMIT_FMT_ONELINE, commit, &sb, 0, NULL, NULL, 0, 0);
146 fprintf(stderr, "%s %s... %s\n", msg,
147 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf);
148 strbuf_release(&sb);
149 }
150
151 static int reset_to_new(struct tree *tree, int quiet)
152 {
153 struct unpack_trees_options opts;
154 struct tree_desc tree_desc;
155
156 memset(&opts, 0, sizeof(opts));
157 opts.head_idx = -1;
158 opts.update = 1;
159 opts.reset = 1;
160 opts.merge = 1;
161 opts.fn = oneway_merge;
162 opts.verbose_update = !quiet;
163 opts.src_index = &the_index;
164 opts.dst_index = &the_index;
165 parse_tree(tree);
166 init_tree_desc(&tree_desc, tree->buffer, tree->size);
167 if (unpack_trees(1, &tree_desc, &opts))
168 return 128;
169 return 0;
170 }
171
172 static void reset_clean_to_new(struct tree *tree, int quiet)
173 {
174 struct unpack_trees_options opts;
175 struct tree_desc tree_desc;
176
177 memset(&opts, 0, sizeof(opts));
178 opts.head_idx = -1;
179 opts.skip_unmerged = 1;
180 opts.reset = 1;
181 opts.merge = 1;
182 opts.fn = oneway_merge;
183 opts.verbose_update = !quiet;
184 opts.src_index = &the_index;
185 opts.dst_index = &the_index;
186 parse_tree(tree);
187 init_tree_desc(&tree_desc, tree->buffer, tree->size);
188 if (unpack_trees(1, &tree_desc, &opts))
189 exit(128);
190 }
191
192 struct checkout_opts {
193 int quiet;
194 int merge;
195 int force;
196
197 char *new_branch;
198 int new_branch_log;
199 enum branch_track track;
200 };
201
202 struct branch_info {
203 const char *name; /* The short name used */
204 const char *path; /* The full name of a real branch */
205 struct commit *commit; /* The named commit */
206 };
207
208 static void setup_branch_path(struct branch_info *branch)
209 {
210 struct strbuf buf;
211 strbuf_init(&buf, 0);
212 strbuf_addstr(&buf, "refs/heads/");
213 strbuf_addstr(&buf, branch->name);
214 branch->path = strbuf_detach(&buf, NULL);
215 }
216
217 static int merge_working_tree(struct checkout_opts *opts,
218 struct branch_info *old, struct branch_info *new)
219 {
220 int ret;
221 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
222 int newfd = hold_locked_index(lock_file, 1);
223 read_cache();
224
225 if (opts->force) {
226 ret = reset_to_new(new->commit->tree, opts->quiet);
227 if (ret)
228 return ret;
229 } else {
230 struct tree_desc trees[2];
231 struct tree *tree;
232 struct unpack_trees_options topts;
233
234 memset(&topts, 0, sizeof(topts));
235 topts.head_idx = -1;
236 topts.src_index = &the_index;
237 topts.dst_index = &the_index;
238
239 refresh_cache(REFRESH_QUIET);
240
241 if (unmerged_cache()) {
242 error("you need to resolve your current index first");
243 return 1;
244 }
245
246 /* 2-way merge to the new branch */
247 topts.update = 1;
248 topts.merge = 1;
249 topts.gently = opts->merge;
250 topts.verbose_update = !opts->quiet;
251 topts.fn = twoway_merge;
252 topts.dir = xcalloc(1, sizeof(*topts.dir));
253 topts.dir->show_ignored = 1;
254 topts.dir->exclude_per_dir = ".gitignore";
255 tree = parse_tree_indirect(old->commit->object.sha1);
256 init_tree_desc(&trees[0], tree->buffer, tree->size);
257 tree = parse_tree_indirect(new->commit->object.sha1);
258 init_tree_desc(&trees[1], tree->buffer, tree->size);
259
260 if (unpack_trees(2, trees, &topts)) {
261 /*
262 * Unpack couldn't do a trivial merge; either
263 * give up or do a real merge, depending on
264 * whether the merge flag was used.
265 */
266 struct tree *result;
267 struct tree *work;
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(0, NULL, NULL);
286 work = write_tree_from_memory();
287
288 ret = reset_to_new(new->commit->tree, opts->quiet);
289 if (ret)
290 return ret;
291 merge_trees(new->commit->tree, work, old->commit->tree,
292 new->name, "local", &result);
293 reset_clean_to_new(new->commit->tree, opts->quiet);
294 }
295 }
296
297 if (write_cache(newfd, active_cache, active_nr) ||
298 commit_locked_index(lock_file))
299 die("unable to write new index file");
300
301 if (!opts->force)
302 show_local_changes(&new->commit->object);
303
304 return 0;
305 }
306
307 static void report_tracking(struct branch_info *new, struct checkout_opts *opts)
308 {
309 /*
310 * We have switched to a new branch; is it building on
311 * top of another branch, and if so does that other branch
312 * have changes we do not have yet?
313 */
314 char *base;
315 unsigned char sha1[20];
316 struct commit *ours, *theirs;
317 char symmetric[84];
318 struct rev_info revs;
319 const char *rev_argv[10];
320 int rev_argc;
321 int num_ours, num_theirs;
322 const char *remote_msg;
323 struct branch *branch = branch_get(new->name);
324
325 /*
326 * Nothing to report unless we are marked to build on top of
327 * somebody else.
328 */
329 if (!branch || !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
330 return;
331
332 /*
333 * If what we used to build on no longer exists, there is
334 * nothing to report.
335 */
336 base = branch->merge[0]->dst;
337 if (!resolve_ref(base, sha1, 1, NULL))
338 return;
339
340 theirs = lookup_commit(sha1);
341 ours = new->commit;
342 if (!hashcmp(sha1, ours->object.sha1))
343 return; /* we are the same */
344
345 /* Run "rev-list --left-right ours...theirs" internally... */
346 rev_argc = 0;
347 rev_argv[rev_argc++] = NULL;
348 rev_argv[rev_argc++] = "--left-right";
349 rev_argv[rev_argc++] = symmetric;
350 rev_argv[rev_argc++] = "--";
351 rev_argv[rev_argc] = NULL;
352
353 strcpy(symmetric, sha1_to_hex(ours->object.sha1));
354 strcpy(symmetric + 40, "...");
355 strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
356
357 init_revisions(&revs, NULL);
358 setup_revisions(rev_argc, rev_argv, &revs, NULL);
359 prepare_revision_walk(&revs);
360
361 /* ... and count the commits on each side. */
362 num_ours = 0;
363 num_theirs = 0;
364 while (1) {
365 struct commit *c = get_revision(&revs);
366 if (!c)
367 break;
368 if (c->object.flags & SYMMETRIC_LEFT)
369 num_ours++;
370 else
371 num_theirs++;
372 }
373
374 if (!prefixcmp(base, "refs/remotes/")) {
375 remote_msg = " remote";
376 base += strlen("refs/remotes/");
377 } else {
378 remote_msg = "";
379 }
380
381 if (!num_theirs)
382 printf("Your branch is ahead of the tracked%s branch '%s' "
383 "by %d commit%s.\n",
384 remote_msg, base,
385 num_ours, (num_ours == 1) ? "" : "s");
386 else if (!num_ours)
387 printf("Your branch is behind the tracked%s branch '%s' "
388 "by %d commit%s,\n"
389 "and can be fast-forwarded.\n",
390 remote_msg, base,
391 num_theirs, (num_theirs == 1) ? "" : "s");
392 else
393 printf("Your branch and the tracked%s branch '%s' "
394 "have diverged,\nand respectively "
395 "have %d and %d different commit(s) each.\n",
396 remote_msg, base,
397 num_ours, num_theirs);
398 }
399
400 static void update_refs_for_switch(struct checkout_opts *opts,
401 struct branch_info *old,
402 struct branch_info *new)
403 {
404 struct strbuf msg;
405 const char *old_desc;
406 if (opts->new_branch) {
407 create_branch(old->name, opts->new_branch, new->name, 0,
408 opts->new_branch_log, opts->track);
409 new->name = opts->new_branch;
410 setup_branch_path(new);
411 }
412
413 strbuf_init(&msg, 0);
414 old_desc = old->name;
415 if (!old_desc)
416 old_desc = sha1_to_hex(old->commit->object.sha1);
417 strbuf_addf(&msg, "checkout: moving from %s to %s",
418 old_desc, new->name);
419
420 if (new->path) {
421 create_symref("HEAD", new->path, msg.buf);
422 if (!opts->quiet) {
423 if (old->path && !strcmp(new->path, old->path))
424 fprintf(stderr, "Already on \"%s\"\n",
425 new->name);
426 else
427 fprintf(stderr, "Switched to%s branch \"%s\"\n",
428 opts->new_branch ? " a new" : "",
429 new->name);
430 }
431 } else if (strcmp(new->name, "HEAD")) {
432 update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
433 REF_NODEREF, DIE_ON_ERR);
434 if (!opts->quiet) {
435 if (old->path)
436 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);
437 describe_detached_head("HEAD is now at", new->commit);
438 }
439 }
440 remove_branch_state();
441 strbuf_release(&msg);
442 if (!opts->quiet && (new->path || !strcmp(new->name, "HEAD")))
443 report_tracking(new, opts);
444 }
445
446 static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
447 {
448 int ret = 0;
449 struct branch_info old;
450 unsigned char rev[20];
451 int flag;
452 memset(&old, 0, sizeof(old));
453 old.path = resolve_ref("HEAD", rev, 0, &flag);
454 old.commit = lookup_commit_reference_gently(rev, 1);
455 if (!(flag & REF_ISSYMREF))
456 old.path = NULL;
457
458 if (old.path && !prefixcmp(old.path, "refs/heads/"))
459 old.name = old.path + strlen("refs/heads/");
460
461 if (!new->name) {
462 new->name = "HEAD";
463 new->commit = old.commit;
464 if (!new->commit)
465 die("You are on a branch yet to be born");
466 parse_commit(new->commit);
467 }
468
469 /*
470 * If the new thing isn't a branch and isn't HEAD and we're
471 * not starting a new branch, and we want messages, and we
472 * weren't on a branch, and we're moving to a new commit,
473 * describe the old commit.
474 */
475 if (!new->path && strcmp(new->name, "HEAD") && !opts->new_branch &&
476 !opts->quiet && !old.path && new->commit != old.commit)
477 describe_detached_head("Previous HEAD position was", old.commit);
478
479 if (!old.commit) {
480 if (!opts->quiet) {
481 fprintf(stderr, "warning: You appear to be on a branch yet to be born.\n");
482 fprintf(stderr, "warning: Forcing checkout of %s.\n", new->name);
483 }
484 opts->force = 1;
485 }
486
487 ret = merge_working_tree(opts, &old, new);
488 if (ret)
489 return ret;
490
491 update_refs_for_switch(opts, &old, new);
492
493 return post_checkout_hook(old.commit, new->commit, 1);
494 }
495
496 int cmd_checkout(int argc, const char **argv, const char *prefix)
497 {
498 struct checkout_opts opts;
499 unsigned char rev[20];
500 const char *arg;
501 struct branch_info new;
502 struct tree *source_tree = NULL;
503 struct option options[] = {
504 OPT__QUIET(&opts.quiet),
505 OPT_STRING('b', NULL, &opts.new_branch, "new branch", "branch"),
506 OPT_BOOLEAN('l', NULL, &opts.new_branch_log, "log for new branch"),
507 OPT_SET_INT('t', "track", &opts.track, "track",
508 BRANCH_TRACK_EXPLICIT),
509 OPT_BOOLEAN('f', NULL, &opts.force, "force"),
510 OPT_BOOLEAN('m', NULL, &opts.merge, "merge"),
511 OPT_END(),
512 };
513
514 memset(&opts, 0, sizeof(opts));
515 memset(&new, 0, sizeof(new));
516
517 git_config(git_default_config, NULL);
518
519 opts.track = git_branch_track;
520
521 argc = parse_options(argc, argv, options, checkout_usage, 0);
522 if (argc) {
523 arg = argv[0];
524 if (get_sha1(arg, rev))
525 ;
526 else if ((new.commit = lookup_commit_reference_gently(rev, 1))) {
527 new.name = arg;
528 setup_branch_path(&new);
529 if (resolve_ref(new.path, rev, 1, NULL))
530 new.commit = lookup_commit_reference(rev);
531 else
532 new.path = NULL;
533 parse_commit(new.commit);
534 source_tree = new.commit->tree;
535 argv++;
536 argc--;
537 } else if ((source_tree = parse_tree_indirect(rev))) {
538 argv++;
539 argc--;
540 }
541 }
542
543 if (argc && !strcmp(argv[0], "--")) {
544 argv++;
545 argc--;
546 }
547
548 if (!opts.new_branch && (opts.track != git_branch_track))
549 die("git checkout: --track and --no-track require -b");
550
551 if (opts.force && opts.merge)
552 die("git checkout: -f and -m are incompatible");
553
554 if (argc) {
555 const char **pathspec = get_pathspec(prefix, argv);
556
557 if (!pathspec)
558 die("invalid path specification");
559
560 /* Checkout paths */
561 if (opts.new_branch || opts.force || opts.merge) {
562 if (argc == 1) {
563 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]);
564 } else {
565 die("git checkout: updating paths is incompatible with switching branches/forcing");
566 }
567 }
568
569 return checkout_paths(source_tree, pathspec);
570 }
571
572 if (new.name && !new.commit) {
573 die("Cannot switch branch to a non-commit.");
574 }
575
576 return switch_branches(&opts, &new);
577 }