Build in checkout
[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"
15
16static const char * const checkout_usage[] = {
17 "git checkout [options] <branch>",
18 "git checkout [options] [<branch>] -- <file>...",
19 NULL,
20};
21
22static int post_checkout_hook(struct commit *old, struct commit *new,
23 int changed)
24{
25 struct child_process proc;
26 const char *name = git_path("hooks/post-checkout");
27 const char *argv[5];
28
29 if (access(name, X_OK) < 0)
30 return 0;
31
32 memset(&proc, 0, sizeof(proc));
33 argv[0] = name;
34 argv[1] = xstrdup(sha1_to_hex(old->object.sha1));
35 argv[2] = xstrdup(sha1_to_hex(new->object.sha1));
36 argv[3] = changed ? "1" : "0";
37 argv[4] = NULL;
38 proc.argv = argv;
39 proc.no_stdin = 1;
40 proc.stdout_to_stderr = 1;
41 return run_command(&proc);
42}
43
44static int update_some(const unsigned char *sha1, const char *base, int baselen,
45 const char *pathname, unsigned mode, int stage)
46{
47 int len;
48 struct cache_entry *ce;
49
50 if (S_ISGITLINK(mode))
51 return 0;
52
53 if (S_ISDIR(mode))
54 return READ_TREE_RECURSIVE;
55
56 len = baselen + strlen(pathname);
57 ce = xcalloc(1, cache_entry_size(len));
58 hashcpy(ce->sha1, sha1);
59 memcpy(ce->name, base, baselen);
60 memcpy(ce->name + baselen, pathname, len - baselen);
61 ce->ce_flags = create_ce_flags(len, 0);
62 ce->ce_mode = create_ce_mode(mode);
63 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
64 return 0;
65}
66
67static int read_tree_some(struct tree *tree, const char **pathspec)
68{
69 int newfd;
70 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
71 newfd = hold_locked_index(lock_file, 1);
72 read_cache();
73
74 read_tree_recursive(tree, "", 0, 0, pathspec, update_some);
75
76 if (write_cache(newfd, active_cache, active_nr) ||
77 commit_locked_index(lock_file))
78 die("unable to write new index file");
79
80 /* update the index with the given tree's info
81 * for all args, expanding wildcards, and exit
82 * with any non-zero return code.
83 */
84 return 0;
85}
86
87static int checkout_paths(const char **pathspec)
88{
89 int pos;
90 struct checkout state;
91 static char *ps_matched;
92 unsigned char rev[20];
93 int flag;
94 struct commit *head;
95
96 for (pos = 0; pathspec[pos]; pos++)
97 ;
98 ps_matched = xcalloc(1, pos);
99
100 for (pos = 0; pos < active_nr; pos++) {
101 struct cache_entry *ce = active_cache[pos];
102 pathspec_match(pathspec, ps_matched, ce->name, 0);
103 }
104
105 if (report_path_error(ps_matched, pathspec, 0))
106 return 1;
107
108 memset(&state, 0, sizeof(state));
109 state.force = 1;
110 state.refresh_cache = 1;
111 for (pos = 0; pos < active_nr; pos++) {
112 struct cache_entry *ce = active_cache[pos];
113 if (pathspec_match(pathspec, NULL, ce->name, 0)) {
114 checkout_entry(ce, &state, NULL);
115 }
116 }
117
118 resolve_ref("HEAD", rev, 0, &flag);
119 head = lookup_commit_reference_gently(rev, 1);
120
121 return post_checkout_hook(head, head, 0);
122}
123
124static void show_local_changes(struct object *head)
125{
126 struct rev_info rev;
127 /* I think we want full paths, even if we're in a subdirectory. */
128 init_revisions(&rev, NULL);
129 rev.abbrev = 0;
130 rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
131 add_pending_object(&rev, head, NULL);
132 run_diff_index(&rev, 0);
133}
134
135static void describe_detached_head(char *msg, struct commit *commit)
136{
137 struct strbuf sb;
138 strbuf_init(&sb, 0);
139 parse_commit(commit);
140 pretty_print_commit(CMIT_FMT_ONELINE, commit, &sb, 0, "", "", 0, 0);
141 fprintf(stderr, "%s %s... %s\n", msg,
142 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf);
143 strbuf_release(&sb);
144}
145
146static int reset_to_new(struct tree *tree, int quiet)
147{
148 struct unpack_trees_options opts;
149 struct tree_desc tree_desc;
150 memset(&opts, 0, sizeof(opts));
151 opts.head_idx = -1;
152 opts.update = 1;
153 opts.reset = 1;
154 opts.merge = 1;
155 opts.fn = oneway_merge;
156 opts.verbose_update = !quiet;
157 parse_tree(tree);
158 init_tree_desc(&tree_desc, tree->buffer, tree->size);
159 if (unpack_trees(1, &tree_desc, &opts))
160 return 128;
161 return 0;
162}
163
164static void reset_clean_to_new(struct tree *tree, int quiet)
165{
166 struct unpack_trees_options opts;
167 struct tree_desc tree_desc;
168 memset(&opts, 0, sizeof(opts));
169 opts.head_idx = -1;
170 opts.skip_unmerged = 1;
171 opts.reset = 1;
172 opts.merge = 1;
173 opts.fn = oneway_merge;
174 opts.verbose_update = !quiet;
175 parse_tree(tree);
176 init_tree_desc(&tree_desc, tree->buffer, tree->size);
177 if (unpack_trees(1, &tree_desc, &opts))
178 exit(128);
179}
180
181struct checkout_opts {
182 int quiet;
183 int merge;
184 int force;
185
186 char *new_branch;
187 int new_branch_log;
188 int track;
189};
190
191struct branch_info {
192 const char *name; /* The short name used */
193 const char *path; /* The full name of a real branch */
194 struct commit *commit; /* The named commit */
195};
196
197static void setup_branch_path(struct branch_info *branch)
198{
199 struct strbuf buf;
200 strbuf_init(&buf, 0);
201 strbuf_addstr(&buf, "refs/heads/");
202 strbuf_addstr(&buf, branch->name);
203 branch->path = strbuf_detach(&buf, NULL);
204}
205
206static int merge_working_tree(struct checkout_opts *opts,
207 struct branch_info *old, struct branch_info *new,
208 const char *prefix)
209{
210 int ret;
211 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
212 int newfd = hold_locked_index(lock_file, 1);
213 read_cache();
214
215 if (opts->force) {
216 ret = reset_to_new(new->commit->tree, opts->quiet);
217 if (ret)
218 return ret;
219 } else {
220 struct tree_desc trees[2];
221 struct tree *tree;
222 struct unpack_trees_options topts;
223 memset(&topts, 0, sizeof(topts));
224 topts.head_idx = -1;
225
226 refresh_cache(REFRESH_QUIET);
227
228 if (unmerged_cache()) {
229 ret = opts->merge ? -1 :
230 error("you need to resolve your current index first");
231 } else {
232 topts.update = 1;
233 topts.merge = 1;
234 topts.gently = opts->merge;
235 topts.fn = twoway_merge;
236 topts.dir = xcalloc(1, sizeof(*topts.dir));
237 topts.dir->show_ignored = 1;
238 topts.dir->exclude_per_dir = ".gitignore";
239 topts.prefix = prefix;
240 tree = parse_tree_indirect(old->commit->object.sha1);
241 init_tree_desc(&trees[0], tree->buffer, tree->size);
242 tree = parse_tree_indirect(new->commit->object.sha1);
243 init_tree_desc(&trees[1], tree->buffer, tree->size);
244 ret = unpack_trees(2, trees, &topts);
245 }
246 if (ret) {
247 /*
248 * Unpack couldn't do a trivial merge; either
249 * give up or do a real merge, depending on
250 * whether the merge flag was used.
251 */
252 struct tree *result;
253 struct tree *work;
254 if (!opts->merge)
255 return 1;
256 parse_commit(old->commit);
257
258 /* Do more real merge */
259
260 /*
261 * We update the index fully, then write the
262 * tree from the index, then merge the new
263 * branch with the current tree, with the old
264 * branch as the base. Then we reset the index
265 * (but not the working tree) to the new
266 * branch, leaving the working tree as the
267 * merged version, but skipping unmerged
268 * entries in the index.
269 */
270
271 add_files_to_cache(0, NULL, NULL);
272 work = write_tree_from_memory();
273
274 ret = reset_to_new(new->commit->tree, opts->quiet);
275 if (ret)
276 return ret;
277 merge_trees(new->commit->tree, work, old->commit->tree,
278 new->name, "local", &result);
279 reset_clean_to_new(new->commit->tree, opts->quiet);
280 }
281 }
282
283 if (write_cache(newfd, active_cache, active_nr) ||
284 commit_locked_index(lock_file))
285 die("unable to write new index file");
286
287 if (!opts->force)
288 show_local_changes(&new->commit->object);
289
290 return 0;
291}
292
293static void update_refs_for_switch(struct checkout_opts *opts,
294 struct branch_info *old,
295 struct branch_info *new)
296{
297 struct strbuf msg;
298 const char *old_desc;
299 if (opts->new_branch) {
300 create_branch(old->name, opts->new_branch, new->name, 0,
301 opts->new_branch_log, opts->track);
302 new->name = opts->new_branch;
303 setup_branch_path(new);
304 }
305
306 strbuf_init(&msg, 0);
307 old_desc = old->name;
308 if (!old_desc)
309 old_desc = sha1_to_hex(old->commit->object.sha1);
310 strbuf_addf(&msg, "checkout: moving from %s to %s",
311 old_desc, new->name);
312
313 if (new->path) {
314 create_symref("HEAD", new->path, msg.buf);
315 if (!opts->quiet) {
316 if (old->path && !strcmp(new->path, old->path))
317 fprintf(stderr, "Already on \"%s\"\n",
318 new->name);
319 else
320 fprintf(stderr, "Switched to%s branch \"%s\"\n",
321 opts->new_branch ? " a new" : "",
322 new->name);
323 }
324 } else if (strcmp(new->name, "HEAD")) {
325 update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
326 REF_NODEREF, DIE_ON_ERR);
327 if (!opts->quiet) {
328 if (old->path)
329 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);
330 describe_detached_head("HEAD is now at", new->commit);
331 }
332 }
333 remove_branch_state();
334 strbuf_release(&msg);
335}
336
337static int switch_branches(struct checkout_opts *opts,
338 struct branch_info *new, const char *prefix)
339{
340 int ret = 0;
341 struct branch_info old;
342 unsigned char rev[20];
343 int flag;
344 memset(&old, 0, sizeof(old));
345 old.path = resolve_ref("HEAD", rev, 0, &flag);
346 old.commit = lookup_commit_reference_gently(rev, 1);
347 if (!(flag & REF_ISSYMREF))
348 old.path = NULL;
349
350 if (old.path && !prefixcmp(old.path, "refs/heads/"))
351 old.name = old.path + strlen("refs/heads/");
352
353 if (!new->name) {
354 new->name = "HEAD";
355 new->commit = old.commit;
356 if (!new->commit)
357 die("You are on a branch yet to be born");
358 parse_commit(new->commit);
359 }
360
361 /*
362 * If the new thing isn't a branch and isn't HEAD and we're
363 * not starting a new branch, and we want messages, and we
364 * weren't on a branch, and we're moving to a new commit,
365 * describe the old commit.
366 */
367 if (!new->path && strcmp(new->name, "HEAD") && !opts->new_branch &&
368 !opts->quiet && !old.path && new->commit != old.commit)
369 describe_detached_head("Previous HEAD position was", old.commit);
370
371 if (!old.commit) {
372 if (!opts->quiet) {
373 fprintf(stderr, "warning: You appear to be on a branch yet to be born.\n");
374 fprintf(stderr, "warning: Forcing checkout of %s.\n", new->name);
375 }
376 opts->force = 1;
377 }
378
379 ret = merge_working_tree(opts, &old, new, prefix);
380 if (ret)
381 return ret;
382
383 update_refs_for_switch(opts, &old, new);
384
385 return post_checkout_hook(old.commit, new->commit, 1);
386}
387
388static int branch_track = 0;
389
390static int git_checkout_config(const char *var, const char *value)
391{
392 if (!strcmp(var, "branch.autosetupmerge"))
393 branch_track = git_config_bool(var, value);
394
395 return git_default_config(var, value);
396}
397
398int cmd_checkout(int argc, const char **argv, const char *prefix)
399{
400 struct checkout_opts opts;
401 unsigned char rev[20];
402 const char *arg;
403 struct branch_info new;
404 struct tree *source_tree = NULL;
405 struct option options[] = {
406 OPT__QUIET(&opts.quiet),
407 OPT_STRING('b', NULL, &opts.new_branch, "new branch", "branch"),
408 OPT_BOOLEAN('l', NULL, &opts.new_branch_log, "log for new branch"),
409 OPT_BOOLEAN( 0 , "track", &opts.track, "track"),
410 OPT_BOOLEAN('f', NULL, &opts.force, "force"),
411 OPT_BOOLEAN('m', NULL, &opts.merge, "merge"),
412 };
413
414 memset(&opts, 0, sizeof(opts));
415 memset(&new, 0, sizeof(new));
416
417 git_config(git_checkout_config);
418
419 opts.track = branch_track;
420
421 argc = parse_options(argc, argv, options, checkout_usage, 0);
422 if (argc) {
423 arg = argv[0];
424 if (get_sha1(arg, rev))
425 ;
426 else if ((new.commit = lookup_commit_reference_gently(rev, 1))) {
427 new.name = arg;
428 setup_branch_path(&new);
429 if (resolve_ref(new.path, rev, 1, NULL))
430 new.commit = lookup_commit_reference(rev);
431 else
432 new.path = NULL;
433 parse_commit(new.commit);
434 source_tree = new.commit->tree;
435 argv++;
436 argc--;
437 } else if ((source_tree = parse_tree_indirect(rev))) {
438 argv++;
439 argc--;
440 }
441 }
442
443 if (argc && !strcmp(argv[0], "--")) {
444 argv++;
445 argc--;
446 }
447
448 if (!opts.new_branch && (opts.track != branch_track))
449 die("git checkout: --track and --no-track require -b");
450
451 if (opts.force && opts.merge)
452 die("git checkout: -f and -m are incompatible");
453
454 if (argc) {
455 const char **pathspec = get_pathspec(prefix, argv);
456 /* Checkout paths */
457 if (opts.new_branch || opts.force || opts.merge) {
458 if (argc == 1) {
459 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]);
460 } else {
461 die("git checkout: updating paths is incompatible with switching branches/forcing");
462 }
463 }
464
465 if (source_tree)
466 read_tree_some(source_tree, pathspec);
467 else
468 read_cache();
469 return checkout_paths(pathspec);
470 }
471
472 if (new.name && !new.commit) {
473 die("Cannot switch branch to a non-commit.");
474 }
475
476 return switch_branches(&opts, &new, prefix);
477}