git.oblomov.eu Git - git/blob - 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 struct checkout_opts {
  24         int quiet;
  25         int merge;
  26         int force;
  27         int writeout_stage;
  28         int writeout_error;
  29
  30         const char *new_branch;
  31         int new_branch_log;
  32         enum branch_track track;
  33 };
  34
  35 static int post_checkout_hook(struct commit *old, struct commit *new,
  36                               int changed)
  37 {
  38         struct child_process proc;
  39         const char *name = git_path("hooks/post-checkout");
  40         const char *argv[5];
  41
  42         if (access(name, X_OK) < 0)
  43                 return 0;
  44
  45         memset(&proc, 0, sizeof(proc));
  46         argv[0] = name;
  47         argv[1] = xstrdup(sha1_to_hex(old->object.sha1));
  48         argv[2] = xstrdup(sha1_to_hex(new->object.sha1));
  49         argv[3] = changed ? "1" : "0";
  50         argv[4] = NULL;
  51         proc.argv = argv;
  52         proc.no_stdin = 1;
  53         proc.stdout_to_stderr = 1;
  54         return run_command(&proc);
  55 }
  56
  57 static int update_some(const unsigned char *sha1, const char *base, int baselen,
  58                 const char *pathname, unsigned mode, int stage, void *context)
  59 {
  60         int len;
  61         struct cache_entry *ce;
  62
  63         if (S_ISGITLINK(mode))
  64                 return 0;
  65
  66         if (S_ISDIR(mode))
  67                 return READ_TREE_RECURSIVE;
  68
  69         len = baselen + strlen(pathname);
  70         ce = xcalloc(1, cache_entry_size(len));
  71         hashcpy(ce->sha1, sha1);
  72         memcpy(ce->name, base, baselen);
  73         memcpy(ce->name + baselen, pathname, len - baselen);
  74         ce->ce_flags = create_ce_flags(len, 0);
  75         ce->ce_mode = create_ce_mode(mode);
  76         add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
  77         return 0;
  78 }
  79
  80 static int read_tree_some(struct tree *tree, const char **pathspec)
  81 {
  82         read_tree_recursive(tree, "", 0, 0, pathspec, update_some, NULL);
  83
  84         /* update the index with the given tree's info
  85          * for all args, expanding wildcards, and exit
  86          * with any non-zero return code.
  87          */
  88         return 0;
  89 }
  90
  91 static int skip_same_name(struct cache_entry *ce, int pos)
  92 {
  93         while (++pos < active_nr &&
  94                !strcmp(active_cache[pos]->name, ce->name))
  95                 ; /* skip */
  96         return pos;
  97 }
  98
  99 static int check_stage(int stage, struct cache_entry *ce, int pos)
 100 {
 101         while (pos < active_nr &&
 102                !strcmp(active_cache[pos]->name, ce->name)) {
 103                 if (ce_stage(active_cache[pos]) == stage)
 104                         return 0;
 105                 pos++;
 106         }
 107         return error("path '%s' does not have %s version",
 108                      ce->name,
 109                      (stage == 2) ? "our" : "their");
 110 }
 111
 112 static int checkout_stage(int stage, struct cache_entry *ce, int pos,
 113                           struct checkout *state)
 114 {
 115         while (pos < active_nr &&
 116                !strcmp(active_cache[pos]->name, ce->name)) {
 117                 if (ce_stage(active_cache[pos]) == stage)
 118                         return checkout_entry(active_cache[pos], state, NULL);
 119                 pos++;
 120         }
 121         return error("path '%s' does not have %s version",
 122                      ce->name,
 123                      (stage == 2) ? "our" : "their");
 124 }
 125
 126 static int checkout_paths(struct tree *source_tree, const char **pathspec,
 127                           struct checkout_opts *opts)
 128 {
 129         int pos;
 130         struct checkout state;
 131         static char *ps_matched;
 132         unsigned char rev[20];
 133         int flag;
 134         struct commit *head;
 135         int errs = 0;
 136         int stage = opts->writeout_stage;
 137         int newfd;
 138         struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
 139
 140         newfd = hold_locked_index(lock_file, 1);
 141         read_cache();
 142
 143         if (source_tree)
 144                 read_tree_some(source_tree, pathspec);
 145
 146         for (pos = 0; pathspec[pos]; pos++)
 147                 ;
 148         ps_matched = xcalloc(1, pos);
 149
 150         for (pos = 0; pos < active_nr; pos++) {
 151                 struct cache_entry *ce = active_cache[pos];
 152                 pathspec_match(pathspec, ps_matched, ce->name, 0);
 153         }
 154
 155         if (report_path_error(ps_matched, pathspec, 0))
 156                 return 1;
 157
 158         /* Any unmerged paths? */
 159         for (pos = 0; pos < active_nr; pos++) {
 160                 struct cache_entry *ce = active_cache[pos];
 161                 if (pathspec_match(pathspec, NULL, ce->name, 0)) {
 162                         if (!ce_stage(ce))
 163                                 continue;
 164                         if (opts->force) {
 165                                 warning("path '%s' is unmerged", ce->name);
 166                         } else if (stage) {
 167                                 errs |= check_stage(stage, ce, pos);
 168                         } else {
 169                                 errs = 1;
 170                                 error("path '%s' is unmerged", ce->name);
 171                         }
 172                         pos = skip_same_name(ce, pos) - 1;
 173                 }
 174         }
 175         if (errs)
 176                 return 1;
 177
 178         /* Now we are committed to check them out */
 179         memset(&state, 0, sizeof(state));
 180         state.force = 1;
 181         state.refresh_cache = 1;
 182         for (pos = 0; pos < active_nr; pos++) {
 183                 struct cache_entry *ce = active_cache[pos];
 184                 if (pathspec_match(pathspec, NULL, ce->name, 0)) {
 185                         if (!ce_stage(ce)) {
 186                                 errs |= checkout_entry(ce, &state, NULL);
 187                                 continue;
 188                         }
 189                         if (stage)
 190                                 errs |= checkout_stage(stage, ce, pos, &state);
 191                         pos = skip_same_name(ce, pos) - 1;
 192                 }
 193         }
 194
 195         if (write_cache(newfd, active_cache, active_nr) ||
 196             commit_locked_index(lock_file))
 197                 die("unable to write new index file");
 198
 199         resolve_ref("HEAD", rev, 0, &flag);
 200         head = lookup_commit_reference_gently(rev, 1);
 201
 202         errs |= post_checkout_hook(head, head, 0);
 203         return errs;
 204 }
 205
 206 static void show_local_changes(struct object *head)
 207 {
 208         struct rev_info rev;
 209         /* I think we want full paths, even if we're in a subdirectory. */
 210         init_revisions(&rev, NULL);
 211         rev.abbrev = 0;
 212         rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
 213         add_pending_object(&rev, head, NULL);
 214         run_diff_index(&rev, 0);
 215 }
 216
 217 static void describe_detached_head(char *msg, struct commit *commit)
 218 {
 219         struct strbuf sb;
 220         strbuf_init(&sb, 0);
 221         parse_commit(commit);
 222         pretty_print_commit(CMIT_FMT_ONELINE, commit, &sb, 0, NULL, NULL, 0, 0);
 223         fprintf(stderr, "%s %s... %s\n", msg,
 224                 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf);
 225         strbuf_release(&sb);
 226 }
 227
 228 static int reset_tree(struct tree *tree, struct checkout_opts *o, int worktree)
 229 {
 230         struct unpack_trees_options opts;
 231         struct tree_desc tree_desc;
 232
 233         memset(&opts, 0, sizeof(opts));
 234         opts.head_idx = -1;
 235         opts.update = worktree;
 236         opts.skip_unmerged = !worktree;
 237         opts.reset = 1;
 238         opts.merge = 1;
 239         opts.fn = oneway_merge;
 240         opts.verbose_update = !o->quiet;
 241         opts.src_index = &the_index;
 242         opts.dst_index = &the_index;
 243         parse_tree(tree);
 244         init_tree_desc(&tree_desc, tree->buffer, tree->size);
 245         switch (unpack_trees(1, &tree_desc, &opts)) {
 246         case -2:
 247                 o->writeout_error = 1;
 248                 /*
 249                  * We return 0 nevertheless, as the index is all right
 250                  * and more importantly we have made best efforts to
 251                  * update paths in the work tree, and we cannot revert
 252                  * them.
 253                  */
 254         case 0:
 255                 return 0;
 256         default:
 257                 return 128;
 258         }
 259 }
 260
 261 struct branch_info {
 262         const char *name; /* The short name used */
 263         const char *path; /* The full name of a real branch */
 264         struct commit *commit; /* The named commit */
 265 };
 266
 267 static void setup_branch_path(struct branch_info *branch)
 268 {
 269         struct strbuf buf;
 270         strbuf_init(&buf, 0);
 271         strbuf_addstr(&buf, "refs/heads/");
 272         strbuf_addstr(&buf, branch->name);
 273         branch->path = strbuf_detach(&buf, NULL);
 274 }
 275
 276 static int merge_working_tree(struct checkout_opts *opts,
 277                               struct branch_info *old, struct branch_info *new)
 278 {
 279         int ret;
 280         struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
 281         int newfd = hold_locked_index(lock_file, 1);
 282         read_cache();
 283
 284         if (opts->force) {
 285                 ret = reset_tree(new->commit->tree, opts, 1);
 286                 if (ret)
 287                         return ret;
 288         } else {
 289                 struct tree_desc trees[2];
 290                 struct tree *tree;
 291                 struct unpack_trees_options topts;
 292
 293                 memset(&topts, 0, sizeof(topts));
 294                 topts.head_idx = -1;
 295                 topts.src_index = &the_index;
 296                 topts.dst_index = &the_index;
 297
 298                 topts.msgs.not_uptodate_file = "You have local changes to '%s'; cannot switch branches.";
 299
 300                 refresh_cache(REFRESH_QUIET);
 301
 302                 if (unmerged_cache()) {
 303                         error("you need to resolve your current index first");
 304                         return 1;
 305                 }
 306
 307                 /* 2-way merge to the new branch */
 308                 topts.update = 1;
 309                 topts.merge = 1;
 310                 topts.gently = opts->merge;
 311                 topts.verbose_update = !opts->quiet;
 312                 topts.fn = twoway_merge;
 313                 topts.dir = xcalloc(1, sizeof(*topts.dir));
 314                 topts.dir->show_ignored = 1;
 315                 topts.dir->exclude_per_dir = ".gitignore";
 316                 tree = parse_tree_indirect(old->commit->object.sha1);
 317                 init_tree_desc(&trees[0], tree->buffer, tree->size);
 318                 tree = parse_tree_indirect(new->commit->object.sha1);
 319                 init_tree_desc(&trees[1], tree->buffer, tree->size);
 320
 321                 ret = unpack_trees(2, trees, &topts);
 322                 if (ret == -1) {
 323                         /*
 324                          * Unpack couldn't do a trivial merge; either
 325                          * give up or do a real merge, depending on
 326                          * whether the merge flag was used.
 327                          */
 328                         struct tree *result;
 329                         struct tree *work;
 330                         if (!opts->merge)
 331                                 return 1;
 332                         parse_commit(old->commit);
 333
 334                         /* Do more real merge */
 335
 336                         /*
 337                          * We update the index fully, then write the
 338                          * tree from the index, then merge the new
 339                          * branch with the current tree, with the old
 340                          * branch as the base. Then we reset the index
 341                          * (but not the working tree) to the new
 342                          * branch, leaving the working tree as the
 343                          * merged version, but skipping unmerged
 344                          * entries in the index.
 345                          */
 346
 347                         add_files_to_cache(NULL, NULL, 0);
 348                         work = write_tree_from_memory();
 349
 350                         ret = reset_tree(new->commit->tree, opts, 1);
 351                         if (ret)
 352                                 return ret;
 353                         merge_trees(new->commit->tree, work, old->commit->tree,
 354                                     new->name, "local", &result);
 355                         ret = reset_tree(new->commit->tree, opts, 0);
 356                         if (ret)
 357                                 return ret;
 358                 }
 359         }
 360
 361         if (write_cache(newfd, active_cache, active_nr) ||
 362             commit_locked_index(lock_file))
 363                 die("unable to write new index file");
 364
 365         if (!opts->force)
 366                 show_local_changes(&new->commit->object);
 367
 368         return 0;
 369 }
 370
 371 static void report_tracking(struct branch_info *new)
 372 {
 373         struct strbuf sb = STRBUF_INIT;
 374         struct branch *branch = branch_get(new->name);
 375
 376         if (!format_tracking_info(branch, &sb))
 377                 return;
 378         fputs(sb.buf, stdout);
 379         strbuf_release(&sb);
 380 }
 381
 382 static void update_refs_for_switch(struct checkout_opts *opts,
 383                                    struct branch_info *old,
 384                                    struct branch_info *new)
 385 {
 386         struct strbuf msg;
 387         const char *old_desc;
 388         if (opts->new_branch) {
 389                 create_branch(old->name, opts->new_branch, new->name, 0,
 390                               opts->new_branch_log, opts->track);
 391                 new->name = opts->new_branch;
 392                 setup_branch_path(new);
 393         }
 394
 395         strbuf_init(&msg, 0);
 396         old_desc = old->name;
 397         if (!old_desc)
 398                 old_desc = sha1_to_hex(old->commit->object.sha1);
 399         strbuf_addf(&msg, "checkout: moving from %s to %s",
 400                     old_desc, new->name);
 401
 402         if (new->path) {
 403                 create_symref("HEAD", new->path, msg.buf);
 404                 if (!opts->quiet) {
 405                         if (old->path && !strcmp(new->path, old->path))
 406                                 fprintf(stderr, "Already on \"%s\"\n",
 407                                         new->name);
 408                         else
 409                                 fprintf(stderr, "Switched to%s branch \"%s\"\n",
 410                                         opts->new_branch ? " a new" : "",
 411                                         new->name);
 412                 }
 413         } else if (strcmp(new->name, "HEAD")) {
 414                 update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
 415                            REF_NODEREF, DIE_ON_ERR);
 416                 if (!opts->quiet) {
 417                         if (old->path)
 418                                 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);
 419                         describe_detached_head("HEAD is now at", new->commit);
 420                 }
 421         }
 422         remove_branch_state();
 423         strbuf_release(&msg);
 424         if (!opts->quiet && (new->path || !strcmp(new->name, "HEAD")))
 425                 report_tracking(new);
 426 }
 427
 428 static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
 429 {
 430         int ret = 0;
 431         struct branch_info old;
 432         unsigned char rev[20];
 433         int flag;
 434         memset(&old, 0, sizeof(old));
 435         old.path = resolve_ref("HEAD", rev, 0, &flag);
 436         old.commit = lookup_commit_reference_gently(rev, 1);
 437         if (!(flag & REF_ISSYMREF))
 438                 old.path = NULL;
 439
 440         if (old.path && !prefixcmp(old.path, "refs/heads/"))
 441                 old.name = old.path + strlen("refs/heads/");
 442
 443         if (!new->name) {
 444                 new->name = "HEAD";
 445                 new->commit = old.commit;
 446                 if (!new->commit)
 447                         die("You are on a branch yet to be born");
 448                 parse_commit(new->commit);
 449         }
 450
 451         /*
 452          * If the new thing isn't a branch and isn't HEAD and we're
 453          * not starting a new branch, and we want messages, and we
 454          * weren't on a branch, and we're moving to a new commit,
 455          * describe the old commit.
 456          */
 457         if (!new->path && strcmp(new->name, "HEAD") && !opts->new_branch &&
 458             !opts->quiet && !old.path && new->commit != old.commit)
 459                 describe_detached_head("Previous HEAD position was", old.commit);
 460
 461         if (!old.commit) {
 462                 if (!opts->quiet) {
 463                         fprintf(stderr, "warning: You appear to be on a branch yet to be born.\n");
 464                         fprintf(stderr, "warning: Forcing checkout of %s.\n", new->name);
 465                 }
 466                 opts->force = 1;
 467         }
 468
 469         ret = merge_working_tree(opts, &old, new);
 470         if (ret)
 471                 return ret;
 472
 473         update_refs_for_switch(opts, &old, new);
 474
 475         ret = post_checkout_hook(old.commit, new->commit, 1);
 476         return ret || opts->writeout_error;
 477 }
 478
 479 int cmd_checkout(int argc, const char **argv, const char *prefix)
 480 {
 481         struct checkout_opts opts;
 482         unsigned char rev[20];
 483         const char *arg;
 484         struct branch_info new;
 485         struct tree *source_tree = NULL;
 486         struct option options[] = {
 487                 OPT__QUIET(&opts.quiet),
 488                 OPT_STRING('b', NULL, &opts.new_branch, "new branch", "branch"),
 489                 OPT_BOOLEAN('l', NULL, &opts.new_branch_log, "log for new branch"),
 490                 OPT_SET_INT('t', "track",  &opts.track, "track",
 491                         BRANCH_TRACK_EXPLICIT),
 492                 OPT_SET_INT('2', "ours", &opts.writeout_stage, "stage",
 493                             2),
 494                 OPT_SET_INT('3', "theirs", &opts.writeout_stage, "stage",
 495                             3),
 496                 OPT_BOOLEAN('f', NULL, &opts.force, "force"),
 497                 OPT_BOOLEAN('m', NULL, &opts.merge, "merge"),
 498                 OPT_END(),
 499         };
 500         int has_dash_dash;
 501
 502         memset(&opts, 0, sizeof(opts));
 503         memset(&new, 0, sizeof(new));
 504
 505         git_config(git_default_config, NULL);
 506
 507         opts.track = git_branch_track;
 508
 509         argc = parse_options(argc, argv, options, checkout_usage,
 510                              PARSE_OPT_KEEP_DASHDASH);
 511
 512         if (!opts.new_branch && (opts.track != git_branch_track))
 513                 die("git checkout: --track and --no-track require -b");
 514
 515         if (opts.force && opts.merge)
 516                 die("git checkout: -f and -m are incompatible");
 517
 518         /*
 519          * case 1: git checkout <ref> -- [<paths>]
 520          *
 521          *   <ref> must be a valid tree, everything after the '--' must be
 522          *   a path.
 523          *
 524          * case 2: git checkout -- [<paths>]
 525          *
 526          *   everything after the '--' must be paths.
 527          *
 528          * case 3: git checkout <something> [<paths>]
 529          *
 530          *   With no paths, if <something> is a commit, that is to
 531          *   switch to the branch or detach HEAD at it.
 532          *
 533          *   Otherwise <something> shall not be ambiguous.
 534          *   - If it's *only* a reference, treat it like case (1).
 535          *   - If it's only a path, treat it like case (2).
 536          *   - else: fail.
 537          *
 538          */
 539         if (argc) {
 540                 if (!strcmp(argv[0], "--")) {       /* case (2) */
 541                         argv++;
 542                         argc--;
 543                         goto no_reference;
 544                 }
 545
 546                 arg = argv[0];
 547                 has_dash_dash = (argc > 1) && !strcmp(argv[1], "--");
 548
 549                 if (get_sha1(arg, rev)) {
 550                         if (has_dash_dash)          /* case (1) */
 551                                 die("invalid reference: %s", arg);
 552                         goto no_reference;          /* case (3 -> 2) */
 553                 }
 554
 555                 /* we can't end up being in (2) anymore, eat the argument */
 556                 argv++;
 557                 argc--;
 558
 559                 if ((new.commit = lookup_commit_reference_gently(rev, 1))) {
 560                         new.name = arg;
 561                         setup_branch_path(&new);
 562                         if (resolve_ref(new.path, rev, 1, NULL))
 563                                 new.commit = lookup_commit_reference(rev);
 564                         else
 565                                 new.path = NULL;
 566                         parse_commit(new.commit);
 567                         source_tree = new.commit->tree;
 568                 } else
 569                         source_tree = parse_tree_indirect(rev);
 570
 571                 if (!source_tree)                   /* case (1): want a tree */
 572                         die("reference is not a tree: %s", arg);
 573                 if (!has_dash_dash) {/* case (3 -> 1) */
 574                         /*
 575                          * Do not complain the most common case
 576                          *      git checkout branch
 577                          * even if there happen to be a file called 'branch';
 578                          * it would be extremely annoying.
 579                          */
 580                         if (argc)
 581                                 verify_non_filename(NULL, arg);
 582                 }
 583                 else {
 584                         argv++;
 585                         argc--;
 586                 }
 587         }
 588
 589 no_reference:
 590         if (argc) {
 591                 const char **pathspec = get_pathspec(prefix, argv);
 592
 593                 if (!pathspec)
 594                         die("invalid path specification");
 595
 596                 /* Checkout paths */
 597                 if (opts.new_branch || opts.merge) {
 598                         if (argc == 1) {
 599                                 die("git checkout: updating paths is incompatible with switching branches.\nDid you intend to checkout '%s' which can not be resolved as commit?", argv[0]);
 600                         } else {
 601                                 die("git checkout: updating paths is incompatible with switching branches.");
 602                         }
 603                 }
 604
 605                 return checkout_paths(source_tree, pathspec, &opts);
 606         }
 607
 608         if (new.name && !new.commit) {
 609                 die("Cannot switch branch to a non-commit.");
 610         }
 611         if (opts.writeout_stage)
 612                 die("--ours/--theirs is incompatible with switching branches.");
 613
 614         return switch_branches(&opts, &new);
 615 }