Documentation: git-cherry uses git-patch-id
[git/git.git] / builtin-checkout.c
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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"
79a1e6b4 15#include "remote.h"
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16
17static const char * const checkout_usage[] = {
18 "git checkout [options] <branch>",
19 "git checkout [options] [<branch>] -- <file>...",
20 NULL,
21};
22
23static 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
45static 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
68static int read_tree_some(struct tree *tree, const char **pathspec)
69{
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70 read_tree_recursive(tree, "", 0, 0, pathspec, update_some);
71
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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
75336878 79static int checkout_paths(struct tree *source_tree, const char **pathspec)
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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
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DB
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
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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
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119 if (write_cache(newfd, active_cache, active_nr) ||
120 commit_locked_index(lock_file))
121 die("unable to write new index file");
122
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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
129static 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
140static void describe_detached_head(char *msg, struct commit *commit)
141{
142 struct strbuf sb;
143 strbuf_init(&sb, 0);
144 parse_commit(commit);
27886318 145 pretty_print_commit(CMIT_FMT_ONELINE, commit, &sb, 0, NULL, NULL, 0, 0);
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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
151static int reset_to_new(struct tree *tree, int quiet)
152{
153 struct unpack_trees_options opts;
154 struct tree_desc tree_desc;
bc052d7f 155
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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;
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163 opts.src_index = &the_index;
164 opts.dst_index = &the_index;
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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
172static void reset_clean_to_new(struct tree *tree, int quiet)
173{
174 struct unpack_trees_options opts;
175 struct tree_desc tree_desc;
bc052d7f 176
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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;
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LT
184 opts.src_index = &the_index;
185 opts.dst_index = &the_index;
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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
192struct checkout_opts {
193 int quiet;
194 int merge;
195 int force;
196
197 char *new_branch;
198 int new_branch_log;
9ed36cfa 199 enum branch_track track;
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200};
201
202struct 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
208static 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
217static int merge_working_tree(struct checkout_opts *opts,
75ea38df 218 struct branch_info *old, struct branch_info *new)
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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;
bc052d7f 233
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234 memset(&topts, 0, sizeof(topts));
235 topts.head_idx = -1;
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LT
236 topts.src_index = &the_index;
237 topts.dst_index = &the_index;
782c2d65 238
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JH
239 topts.msgs.not_uptodate_file = "You have local changes to '%s'; cannot switch branches.";
240
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241 refresh_cache(REFRESH_QUIET);
242
243 if (unmerged_cache()) {
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244 error("you need to resolve your current index first");
245 return 1;
782c2d65 246 }
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247
248 /* 2-way merge to the new branch */
249 topts.update = 1;
250 topts.merge = 1;
251 topts.gently = opts->merge;
252 topts.verbose_update = !opts->quiet;
253 topts.fn = twoway_merge;
254 topts.dir = xcalloc(1, sizeof(*topts.dir));
255 topts.dir->show_ignored = 1;
256 topts.dir->exclude_per_dir = ".gitignore";
257 tree = parse_tree_indirect(old->commit->object.sha1);
258 init_tree_desc(&trees[0], tree->buffer, tree->size);
259 tree = parse_tree_indirect(new->commit->object.sha1);
260 init_tree_desc(&trees[1], tree->buffer, tree->size);
261
262 if (unpack_trees(2, trees, &topts)) {
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263 /*
264 * Unpack couldn't do a trivial merge; either
265 * give up or do a real merge, depending on
266 * whether the merge flag was used.
267 */
268 struct tree *result;
269 struct tree *work;
270 if (!opts->merge)
271 return 1;
272 parse_commit(old->commit);
273
274 /* Do more real merge */
275
276 /*
277 * We update the index fully, then write the
278 * tree from the index, then merge the new
279 * branch with the current tree, with the old
280 * branch as the base. Then we reset the index
281 * (but not the working tree) to the new
282 * branch, leaving the working tree as the
283 * merged version, but skipping unmerged
284 * entries in the index.
285 */
286
7ae02a30 287 add_files_to_cache(NULL, NULL, 0);
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288 work = write_tree_from_memory();
289
290 ret = reset_to_new(new->commit->tree, opts->quiet);
291 if (ret)
292 return ret;
293 merge_trees(new->commit->tree, work, old->commit->tree,
294 new->name, "local", &result);
295 reset_clean_to_new(new->commit->tree, opts->quiet);
296 }
297 }
298
299 if (write_cache(newfd, active_cache, active_nr) ||
300 commit_locked_index(lock_file))
301 die("unable to write new index file");
302
303 if (!opts->force)
304 show_local_changes(&new->commit->object);
305
306 return 0;
307}
308
b56fca07 309static void report_tracking(struct branch_info *new, struct checkout_opts *opts)
79a1e6b4
JH
310{
311 /*
312 * We have switched to a new branch; is it building on
313 * top of another branch, and if so does that other branch
314 * have changes we do not have yet?
315 */
316 char *base;
317 unsigned char sha1[20];
318 struct commit *ours, *theirs;
79a1e6b4 319 char symmetric[84];
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JH
320 struct rev_info revs;
321 const char *rev_argv[10];
322 int rev_argc;
323 int num_ours, num_theirs;
324 const char *remote_msg;
b56fca07 325 struct branch *branch = branch_get(new->name);
79a1e6b4 326
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JH
327 /*
328 * Nothing to report unless we are marked to build on top of
329 * somebody else.
330 */
b56fca07 331 if (!branch || !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
79a1e6b4 332 return;
79a1e6b4 333
79a1e6b4 334 /*
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JH
335 * If what we used to build on no longer exists, there is
336 * nothing to report.
79a1e6b4 337 */
b0030db3 338 base = branch->merge[0]->dst;
79a1e6b4
JH
339 if (!resolve_ref(base, sha1, 1, NULL))
340 return;
79a1e6b4 341
b0030db3
JH
342 theirs = lookup_commit(sha1);
343 ours = new->commit;
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JH
344 if (!hashcmp(sha1, ours->object.sha1))
345 return; /* we are the same */
346
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JH
347 /* Run "rev-list --left-right ours...theirs" internally... */
348 rev_argc = 0;
349 rev_argv[rev_argc++] = NULL;
350 rev_argv[rev_argc++] = "--left-right";
351 rev_argv[rev_argc++] = symmetric;
352 rev_argv[rev_argc++] = "--";
353 rev_argv[rev_argc] = NULL;
354
355 strcpy(symmetric, sha1_to_hex(ours->object.sha1));
356 strcpy(symmetric + 40, "...");
357 strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
358
359 init_revisions(&revs, NULL);
360 setup_revisions(rev_argc, rev_argv, &revs, NULL);
361 prepare_revision_walk(&revs);
362
363 /* ... and count the commits on each side. */
364 num_ours = 0;
365 num_theirs = 0;
366 while (1) {
367 struct commit *c = get_revision(&revs);
368 if (!c)
369 break;
370 if (c->object.flags & SYMMETRIC_LEFT)
371 num_ours++;
372 else
373 num_theirs++;
79a1e6b4 374 }
79a1e6b4 375
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JH
376 if (!prefixcmp(base, "refs/remotes/")) {
377 remote_msg = " remote";
79a1e6b4 378 base += strlen("refs/remotes/");
b0030db3
JH
379 } else {
380 remote_msg = "";
79a1e6b4 381 }
79a1e6b4 382
b0030db3
JH
383 if (!num_theirs)
384 printf("Your branch is ahead of the tracked%s branch '%s' "
385 "by %d commit%s.\n",
386 remote_msg, base,
387 num_ours, (num_ours == 1) ? "" : "s");
388 else if (!num_ours)
b56fca07 389 printf("Your branch is behind the tracked%s branch '%s' "
b0030db3
JH
390 "by %d commit%s,\n"
391 "and can be fast-forwarded.\n",
392 remote_msg, base,
393 num_theirs, (num_theirs == 1) ? "" : "s");
394 else
395 printf("Your branch and the tracked%s branch '%s' "
396 "have diverged,\nand respectively "
397 "have %d and %d different commit(s) each.\n",
398 remote_msg, base,
399 num_ours, num_theirs);
400}
79a1e6b4 401
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402static void update_refs_for_switch(struct checkout_opts *opts,
403 struct branch_info *old,
404 struct branch_info *new)
405{
406 struct strbuf msg;
407 const char *old_desc;
408 if (opts->new_branch) {
409 create_branch(old->name, opts->new_branch, new->name, 0,
410 opts->new_branch_log, opts->track);
411 new->name = opts->new_branch;
412 setup_branch_path(new);
413 }
414
415 strbuf_init(&msg, 0);
416 old_desc = old->name;
417 if (!old_desc)
418 old_desc = sha1_to_hex(old->commit->object.sha1);
419 strbuf_addf(&msg, "checkout: moving from %s to %s",
420 old_desc, new->name);
421
422 if (new->path) {
423 create_symref("HEAD", new->path, msg.buf);
424 if (!opts->quiet) {
425 if (old->path && !strcmp(new->path, old->path))
426 fprintf(stderr, "Already on \"%s\"\n",
427 new->name);
428 else
429 fprintf(stderr, "Switched to%s branch \"%s\"\n",
430 opts->new_branch ? " a new" : "",
431 new->name);
432 }
433 } else if (strcmp(new->name, "HEAD")) {
434 update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
435 REF_NODEREF, DIE_ON_ERR);
436 if (!opts->quiet) {
437 if (old->path)
438 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);
439 describe_detached_head("HEAD is now at", new->commit);
440 }
441 }
442 remove_branch_state();
443 strbuf_release(&msg);
b0030db3 444 if (!opts->quiet && (new->path || !strcmp(new->name, "HEAD")))
b56fca07 445 report_tracking(new, opts);
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DB
446}
447
75ea38df 448static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
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DB
449{
450 int ret = 0;
451 struct branch_info old;
452 unsigned char rev[20];
453 int flag;
454 memset(&old, 0, sizeof(old));
455 old.path = resolve_ref("HEAD", rev, 0, &flag);
456 old.commit = lookup_commit_reference_gently(rev, 1);
457 if (!(flag & REF_ISSYMREF))
458 old.path = NULL;
459
460 if (old.path && !prefixcmp(old.path, "refs/heads/"))
461 old.name = old.path + strlen("refs/heads/");
462
463 if (!new->name) {
464 new->name = "HEAD";
465 new->commit = old.commit;
466 if (!new->commit)
467 die("You are on a branch yet to be born");
468 parse_commit(new->commit);
469 }
470
471 /*
472 * If the new thing isn't a branch and isn't HEAD and we're
473 * not starting a new branch, and we want messages, and we
474 * weren't on a branch, and we're moving to a new commit,
475 * describe the old commit.
476 */
477 if (!new->path && strcmp(new->name, "HEAD") && !opts->new_branch &&
478 !opts->quiet && !old.path && new->commit != old.commit)
479 describe_detached_head("Previous HEAD position was", old.commit);
480
481 if (!old.commit) {
482 if (!opts->quiet) {
483 fprintf(stderr, "warning: You appear to be on a branch yet to be born.\n");
484 fprintf(stderr, "warning: Forcing checkout of %s.\n", new->name);
485 }
486 opts->force = 1;
487 }
488
75ea38df 489 ret = merge_working_tree(opts, &old, new);
782c2d65
DB
490 if (ret)
491 return ret;
492
493 update_refs_for_switch(opts, &old, new);
494
495 return post_checkout_hook(old.commit, new->commit, 1);
496}
497
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DB
498int cmd_checkout(int argc, const char **argv, const char *prefix)
499{
500 struct checkout_opts opts;
501 unsigned char rev[20];
502 const char *arg;
503 struct branch_info new;
504 struct tree *source_tree = NULL;
505 struct option options[] = {
506 OPT__QUIET(&opts.quiet),
507 OPT_STRING('b', NULL, &opts.new_branch, "new branch", "branch"),
508 OPT_BOOLEAN('l', NULL, &opts.new_branch_log, "log for new branch"),
498a6e7e 509 OPT_SET_INT('t', "track", &opts.track, "track",
9ed36cfa 510 BRANCH_TRACK_EXPLICIT),
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DB
511 OPT_BOOLEAN('f', NULL, &opts.force, "force"),
512 OPT_BOOLEAN('m', NULL, &opts.merge, "merge"),
b249b552 513 OPT_END(),
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DB
514 };
515
516 memset(&opts, 0, sizeof(opts));
517 memset(&new, 0, sizeof(new));
518
ef90d6d4 519 git_config(git_default_config, NULL);
782c2d65 520
9ed36cfa 521 opts.track = git_branch_track;
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DB
522
523 argc = parse_options(argc, argv, options, checkout_usage, 0);
524 if (argc) {
525 arg = argv[0];
526 if (get_sha1(arg, rev))
527 ;
528 else if ((new.commit = lookup_commit_reference_gently(rev, 1))) {
529 new.name = arg;
530 setup_branch_path(&new);
531 if (resolve_ref(new.path, rev, 1, NULL))
532 new.commit = lookup_commit_reference(rev);
533 else
534 new.path = NULL;
535 parse_commit(new.commit);
536 source_tree = new.commit->tree;
537 argv++;
538 argc--;
539 } else if ((source_tree = parse_tree_indirect(rev))) {
540 argv++;
541 argc--;
542 }
543 }
544
545 if (argc && !strcmp(argv[0], "--")) {
546 argv++;
547 argc--;
548 }
549
9ed36cfa 550 if (!opts.new_branch && (opts.track != git_branch_track))
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DB
551 die("git checkout: --track and --no-track require -b");
552
553 if (opts.force && opts.merge)
554 die("git checkout: -f and -m are incompatible");
555
556 if (argc) {
557 const char **pathspec = get_pathspec(prefix, argv);
301e42ed
AR
558
559 if (!pathspec)
560 die("invalid path specification");
561
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DB
562 /* Checkout paths */
563 if (opts.new_branch || opts.force || opts.merge) {
564 if (argc == 1) {
565 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]);
566 } else {
567 die("git checkout: updating paths is incompatible with switching branches/forcing");
568 }
569 }
570
75336878 571 return checkout_paths(source_tree, pathspec);
782c2d65
DB
572 }
573
574 if (new.name && !new.commit) {
575 die("Cannot switch branch to a non-commit.");
576 }
577
75ea38df 578 return switch_branches(&opts, &new);
782c2d65 579}