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 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, "", "", 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.index = &the_index;
 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
 171 static void reset_clean_to_new(struct tree *tree, int quiet)
 172 {
 173         struct unpack_trees_options opts;
 174         struct tree_desc tree_desc;
 175
 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;
 183         opts.index = &the_index;
 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
 190 struct checkout_opts {
 191         int quiet;
 192         int merge;
 193         int force;
 194
 195         char *new_branch;
 196         int new_branch_log;
 197         enum branch_track track;
 198 };
 199
 200 struct 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
 206 static 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
 215 static int merge_working_tree(struct checkout_opts *opts,
 216                               struct branch_info *old, struct branch_info *new)
 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;
 231
 232                 memset(&topts, 0, sizeof(topts));
 233                 topts.head_idx = -1;
 234                 topts.index = &the_index;
 235
 236                 refresh_cache(REFRESH_QUIET);
 237
 238                 if (unmerged_cache()) {
 239                         error("you need to resolve your current index first");
 240                         return 1;
 241                 }
 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)) {
 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
 304 static void report_tracking(struct branch_info *new, struct checkout_opts *opts)
 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;
 314         char symmetric[84];
 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;
 320         struct branch *branch = branch_get(new->name);
 321
 322         /*
 323          * Nothing to report unless we are marked to build on top of
 324          * somebody else.
 325          */
 326         if (!branch || !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
 327                 return;
 328
 329         /*
 330          * If what we used to build on no longer exists, there is
 331          * nothing to report.
 332          */
 333         base = branch->merge[0]->dst;
 334         if (!resolve_ref(base, sha1, 1, NULL))
 335                 return;
 336
 337         theirs = lookup_commit(sha1);
 338         ours = new->commit;
 339         if (!hashcmp(sha1, ours->object.sha1))
 340                 return; /* we are the same */
 341
 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++;
 369         }
 370
 371         if (!prefixcmp(base, "refs/remotes/")) {
 372                 remote_msg = " remote";
 373                 base += strlen("refs/remotes/");
 374         } else {
 375                 remote_msg = "";
 376         }
 377
 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)
 384                 printf("Your branch is behind the tracked%s branch '%s' "
 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 }
 396
 397 static 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);
 439         if (!opts->quiet && (new->path || !strcmp(new->name, "HEAD")))
 440                 report_tracking(new, opts);
 441 }
 442
 443 static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
 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
 484         ret = merge_working_tree(opts, &old, new);
 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
 493 int 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"),
 504                 OPT_SET_INT( 0 , "track",  &opts.track, "track",
 505                         BRANCH_TRACK_EXPLICIT),
 506                 OPT_BOOLEAN('f', NULL, &opts.force, "force"),
 507                 OPT_BOOLEAN('m', NULL, &opts.merge, "merge"),
 508                 OPT_END(),
 509         };
 510
 511         memset(&opts, 0, sizeof(opts));
 512         memset(&new, 0, sizeof(new));
 513
 514         git_config(git_default_config);
 515
 516         opts.track = git_branch_track;
 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
 545         if (!opts.new_branch && (opts.track != git_branch_track))
 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);
 553
 554                 if (!pathspec)
 555                         die("invalid path specification");
 556
 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
 566                 return checkout_paths(source_tree, pathspec);
 567         }
 568
 569         if (new.name && !new.commit) {
 570                 die("Cannot switch branch to a non-commit.");
 571         }
 572
 573         return switch_branches(&opts, &new);
 574 }