Make 'unpack_trees()' take the index to work on as an argument
[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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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);
145 pretty_print_commit(CMIT_FMT_ONELINE, commit, &sb, 0, "", "", 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
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;
bc052d7f 163 opts.index = &the_index;
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164 parse_tree(tree);
165 init_tree_desc(&tree_desc, tree->buffer, tree->size);
166 if (unpack_trees(1, &tree_desc, &opts))
167 return 128;
168 return 0;
169}
170
171static void reset_clean_to_new(struct tree *tree, int quiet)
172{
173 struct unpack_trees_options opts;
174 struct tree_desc tree_desc;
bc052d7f 175
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176 memset(&opts, 0, sizeof(opts));
177 opts.head_idx = -1;
178 opts.skip_unmerged = 1;
179 opts.reset = 1;
180 opts.merge = 1;
181 opts.fn = oneway_merge;
182 opts.verbose_update = !quiet;
bc052d7f 183 opts.index = &the_index;
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184 parse_tree(tree);
185 init_tree_desc(&tree_desc, tree->buffer, tree->size);
186 if (unpack_trees(1, &tree_desc, &opts))
187 exit(128);
188}
189
190struct checkout_opts {
191 int quiet;
192 int merge;
193 int force;
194
195 char *new_branch;
196 int new_branch_log;
9ed36cfa 197 enum branch_track track;
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198};
199
200struct branch_info {
201 const char *name; /* The short name used */
202 const char *path; /* The full name of a real branch */
203 struct commit *commit; /* The named commit */
204};
205
206static void setup_branch_path(struct branch_info *branch)
207{
208 struct strbuf buf;
209 strbuf_init(&buf, 0);
210 strbuf_addstr(&buf, "refs/heads/");
211 strbuf_addstr(&buf, branch->name);
212 branch->path = strbuf_detach(&buf, NULL);
213}
214
215static int merge_working_tree(struct checkout_opts *opts,
75ea38df 216 struct branch_info *old, struct branch_info *new)
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217{
218 int ret;
219 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
220 int newfd = hold_locked_index(lock_file, 1);
221 read_cache();
222
223 if (opts->force) {
224 ret = reset_to_new(new->commit->tree, opts->quiet);
225 if (ret)
226 return ret;
227 } else {
228 struct tree_desc trees[2];
229 struct tree *tree;
230 struct unpack_trees_options topts;
bc052d7f 231
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232 memset(&topts, 0, sizeof(topts));
233 topts.head_idx = -1;
bc052d7f 234 topts.index = &the_index;
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235
236 refresh_cache(REFRESH_QUIET);
237
238 if (unmerged_cache()) {
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239 error("you need to resolve your current index first");
240 return 1;
782c2d65 241 }
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242
243 /* 2-way merge to the new branch */
244 topts.update = 1;
245 topts.merge = 1;
246 topts.gently = opts->merge;
247 topts.verbose_update = !opts->quiet;
248 topts.fn = twoway_merge;
249 topts.dir = xcalloc(1, sizeof(*topts.dir));
250 topts.dir->show_ignored = 1;
251 topts.dir->exclude_per_dir = ".gitignore";
252 tree = parse_tree_indirect(old->commit->object.sha1);
253 init_tree_desc(&trees[0], tree->buffer, tree->size);
254 tree = parse_tree_indirect(new->commit->object.sha1);
255 init_tree_desc(&trees[1], tree->buffer, tree->size);
256
257 if (unpack_trees(2, trees, &topts)) {
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258 /*
259 * Unpack couldn't do a trivial merge; either
260 * give up or do a real merge, depending on
261 * whether the merge flag was used.
262 */
263 struct tree *result;
264 struct tree *work;
265 if (!opts->merge)
266 return 1;
267 parse_commit(old->commit);
268
269 /* Do more real merge */
270
271 /*
272 * We update the index fully, then write the
273 * tree from the index, then merge the new
274 * branch with the current tree, with the old
275 * branch as the base. Then we reset the index
276 * (but not the working tree) to the new
277 * branch, leaving the working tree as the
278 * merged version, but skipping unmerged
279 * entries in the index.
280 */
281
282 add_files_to_cache(0, NULL, NULL);
283 work = write_tree_from_memory();
284
285 ret = reset_to_new(new->commit->tree, opts->quiet);
286 if (ret)
287 return ret;
288 merge_trees(new->commit->tree, work, old->commit->tree,
289 new->name, "local", &result);
290 reset_clean_to_new(new->commit->tree, opts->quiet);
291 }
292 }
293
294 if (write_cache(newfd, active_cache, active_nr) ||
295 commit_locked_index(lock_file))
296 die("unable to write new index file");
297
298 if (!opts->force)
299 show_local_changes(&new->commit->object);
300
301 return 0;
302}
303
b56fca07 304static void report_tracking(struct branch_info *new, struct checkout_opts *opts)
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305{
306 /*
307 * We have switched to a new branch; is it building on
308 * top of another branch, and if so does that other branch
309 * have changes we do not have yet?
310 */
311 char *base;
312 unsigned char sha1[20];
313 struct commit *ours, *theirs;
79a1e6b4 314 char symmetric[84];
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315 struct rev_info revs;
316 const char *rev_argv[10];
317 int rev_argc;
318 int num_ours, num_theirs;
319 const char *remote_msg;
b56fca07 320 struct branch *branch = branch_get(new->name);
79a1e6b4 321
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322 /*
323 * Nothing to report unless we are marked to build on top of
324 * somebody else.
325 */
b56fca07 326 if (!branch || !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
79a1e6b4 327 return;
79a1e6b4 328
79a1e6b4 329 /*
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330 * If what we used to build on no longer exists, there is
331 * nothing to report.
79a1e6b4 332 */
b0030db3 333 base = branch->merge[0]->dst;
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334 if (!resolve_ref(base, sha1, 1, NULL))
335 return;
79a1e6b4 336
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337 theirs = lookup_commit(sha1);
338 ours = new->commit;
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339 if (!hashcmp(sha1, ours->object.sha1))
340 return; /* we are the same */
341
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342 /* Run "rev-list --left-right ours...theirs" internally... */
343 rev_argc = 0;
344 rev_argv[rev_argc++] = NULL;
345 rev_argv[rev_argc++] = "--left-right";
346 rev_argv[rev_argc++] = symmetric;
347 rev_argv[rev_argc++] = "--";
348 rev_argv[rev_argc] = NULL;
349
350 strcpy(symmetric, sha1_to_hex(ours->object.sha1));
351 strcpy(symmetric + 40, "...");
352 strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
353
354 init_revisions(&revs, NULL);
355 setup_revisions(rev_argc, rev_argv, &revs, NULL);
356 prepare_revision_walk(&revs);
357
358 /* ... and count the commits on each side. */
359 num_ours = 0;
360 num_theirs = 0;
361 while (1) {
362 struct commit *c = get_revision(&revs);
363 if (!c)
364 break;
365 if (c->object.flags & SYMMETRIC_LEFT)
366 num_ours++;
367 else
368 num_theirs++;
79a1e6b4 369 }
79a1e6b4 370
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371 if (!prefixcmp(base, "refs/remotes/")) {
372 remote_msg = " remote";
79a1e6b4 373 base += strlen("refs/remotes/");
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374 } else {
375 remote_msg = "";
79a1e6b4 376 }
79a1e6b4 377
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378 if (!num_theirs)
379 printf("Your branch is ahead of the tracked%s branch '%s' "
380 "by %d commit%s.\n",
381 remote_msg, base,
382 num_ours, (num_ours == 1) ? "" : "s");
383 else if (!num_ours)
b56fca07 384 printf("Your branch is behind the tracked%s branch '%s' "
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385 "by %d commit%s,\n"
386 "and can be fast-forwarded.\n",
387 remote_msg, base,
388 num_theirs, (num_theirs == 1) ? "" : "s");
389 else
390 printf("Your branch and the tracked%s branch '%s' "
391 "have diverged,\nand respectively "
392 "have %d and %d different commit(s) each.\n",
393 remote_msg, base,
394 num_ours, num_theirs);
395}
79a1e6b4 396
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397static void update_refs_for_switch(struct checkout_opts *opts,
398 struct branch_info *old,
399 struct branch_info *new)
400{
401 struct strbuf msg;
402 const char *old_desc;
403 if (opts->new_branch) {
404 create_branch(old->name, opts->new_branch, new->name, 0,
405 opts->new_branch_log, opts->track);
406 new->name = opts->new_branch;
407 setup_branch_path(new);
408 }
409
410 strbuf_init(&msg, 0);
411 old_desc = old->name;
412 if (!old_desc)
413 old_desc = sha1_to_hex(old->commit->object.sha1);
414 strbuf_addf(&msg, "checkout: moving from %s to %s",
415 old_desc, new->name);
416
417 if (new->path) {
418 create_symref("HEAD", new->path, msg.buf);
419 if (!opts->quiet) {
420 if (old->path && !strcmp(new->path, old->path))
421 fprintf(stderr, "Already on \"%s\"\n",
422 new->name);
423 else
424 fprintf(stderr, "Switched to%s branch \"%s\"\n",
425 opts->new_branch ? " a new" : "",
426 new->name);
427 }
428 } else if (strcmp(new->name, "HEAD")) {
429 update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
430 REF_NODEREF, DIE_ON_ERR);
431 if (!opts->quiet) {
432 if (old->path)
433 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);
434 describe_detached_head("HEAD is now at", new->commit);
435 }
436 }
437 remove_branch_state();
438 strbuf_release(&msg);
b0030db3 439 if (!opts->quiet && (new->path || !strcmp(new->name, "HEAD")))
b56fca07 440 report_tracking(new, opts);
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441}
442
75ea38df 443static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
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444{
445 int ret = 0;
446 struct branch_info old;
447 unsigned char rev[20];
448 int flag;
449 memset(&old, 0, sizeof(old));
450 old.path = resolve_ref("HEAD", rev, 0, &flag);
451 old.commit = lookup_commit_reference_gently(rev, 1);
452 if (!(flag & REF_ISSYMREF))
453 old.path = NULL;
454
455 if (old.path && !prefixcmp(old.path, "refs/heads/"))
456 old.name = old.path + strlen("refs/heads/");
457
458 if (!new->name) {
459 new->name = "HEAD";
460 new->commit = old.commit;
461 if (!new->commit)
462 die("You are on a branch yet to be born");
463 parse_commit(new->commit);
464 }
465
466 /*
467 * If the new thing isn't a branch and isn't HEAD and we're
468 * not starting a new branch, and we want messages, and we
469 * weren't on a branch, and we're moving to a new commit,
470 * describe the old commit.
471 */
472 if (!new->path && strcmp(new->name, "HEAD") && !opts->new_branch &&
473 !opts->quiet && !old.path && new->commit != old.commit)
474 describe_detached_head("Previous HEAD position was", old.commit);
475
476 if (!old.commit) {
477 if (!opts->quiet) {
478 fprintf(stderr, "warning: You appear to be on a branch yet to be born.\n");
479 fprintf(stderr, "warning: Forcing checkout of %s.\n", new->name);
480 }
481 opts->force = 1;
482 }
483
75ea38df 484 ret = merge_working_tree(opts, &old, new);
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DB
485 if (ret)
486 return ret;
487
488 update_refs_for_switch(opts, &old, new);
489
490 return post_checkout_hook(old.commit, new->commit, 1);
491}
492
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493int cmd_checkout(int argc, const char **argv, const char *prefix)
494{
495 struct checkout_opts opts;
496 unsigned char rev[20];
497 const char *arg;
498 struct branch_info new;
499 struct tree *source_tree = NULL;
500 struct option options[] = {
501 OPT__QUIET(&opts.quiet),
502 OPT_STRING('b', NULL, &opts.new_branch, "new branch", "branch"),
503 OPT_BOOLEAN('l', NULL, &opts.new_branch_log, "log for new branch"),
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504 OPT_SET_INT( 0 , "track", &opts.track, "track",
505 BRANCH_TRACK_EXPLICIT),
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506 OPT_BOOLEAN('f', NULL, &opts.force, "force"),
507 OPT_BOOLEAN('m', NULL, &opts.merge, "merge"),
b249b552 508 OPT_END(),
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509 };
510
511 memset(&opts, 0, sizeof(opts));
512 memset(&new, 0, sizeof(new));
513
a3647bee 514 git_config(git_default_config);
782c2d65 515
9ed36cfa 516 opts.track = git_branch_track;
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517
518 argc = parse_options(argc, argv, options, checkout_usage, 0);
519 if (argc) {
520 arg = argv[0];
521 if (get_sha1(arg, rev))
522 ;
523 else if ((new.commit = lookup_commit_reference_gently(rev, 1))) {
524 new.name = arg;
525 setup_branch_path(&new);
526 if (resolve_ref(new.path, rev, 1, NULL))
527 new.commit = lookup_commit_reference(rev);
528 else
529 new.path = NULL;
530 parse_commit(new.commit);
531 source_tree = new.commit->tree;
532 argv++;
533 argc--;
534 } else if ((source_tree = parse_tree_indirect(rev))) {
535 argv++;
536 argc--;
537 }
538 }
539
540 if (argc && !strcmp(argv[0], "--")) {
541 argv++;
542 argc--;
543 }
544
9ed36cfa 545 if (!opts.new_branch && (opts.track != git_branch_track))
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546 die("git checkout: --track and --no-track require -b");
547
548 if (opts.force && opts.merge)
549 die("git checkout: -f and -m are incompatible");
550
551 if (argc) {
552 const char **pathspec = get_pathspec(prefix, argv);
301e42ed
AR
553
554 if (!pathspec)
555 die("invalid path specification");
556
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557 /* Checkout paths */
558 if (opts.new_branch || opts.force || opts.merge) {
559 if (argc == 1) {
560 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]);
561 } else {
562 die("git checkout: updating paths is incompatible with switching branches/forcing");
563 }
564 }
565
75336878 566 return checkout_paths(source_tree, pathspec);
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567 }
568
569 if (new.name && !new.commit) {
570 die("Cannot switch branch to a non-commit.");
571 }
572
75ea38df 573 return switch_branches(&opts, &new);
782c2d65 574}