builtin-checkout.con commit Start 1.6.0.4 cycle (1a9016a)
   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
  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, void *context)
  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{
  70        read_tree_recursive(tree, "", 0, 0, pathspec, update_some, NULL);
  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
  79static int skip_same_name(struct cache_entry *ce, int pos)
  80{
  81        while (++pos < active_nr &&
  82               !strcmp(active_cache[pos]->name, ce->name))
  83                ; /* skip */
  84        return pos;
  85}
  86
  87
  88static int checkout_paths(struct tree *source_tree, const char **pathspec)
  89{
  90        int pos;
  91        struct checkout state;
  92        static char *ps_matched;
  93        unsigned char rev[20];
  94        int flag;
  95        struct commit *head;
  96        int errs = 0;
  97
  98        int newfd;
  99        struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
 100
 101        newfd = hold_locked_index(lock_file, 1);
 102        read_cache();
 103
 104        if (source_tree)
 105                read_tree_some(source_tree, pathspec);
 106
 107        for (pos = 0; pathspec[pos]; pos++)
 108                ;
 109        ps_matched = xcalloc(1, pos);
 110
 111        for (pos = 0; pos < active_nr; pos++) {
 112                struct cache_entry *ce = active_cache[pos];
 113                pathspec_match(pathspec, ps_matched, ce->name, 0);
 114        }
 115
 116        if (report_path_error(ps_matched, pathspec, 0))
 117                return 1;
 118
 119        /* Any unmerged paths? */
 120        for (pos = 0; pos < active_nr; pos++) {
 121                struct cache_entry *ce = active_cache[pos];
 122                if (pathspec_match(pathspec, NULL, ce->name, 0)) {
 123                        if (!ce_stage(ce))
 124                                continue;
 125                        errs = 1;
 126                        error("path '%s' is unmerged", ce->name);
 127                        pos = skip_same_name(ce, pos) - 1;
 128                }
 129        }
 130        if (errs)
 131                return 1;
 132
 133        /* Now we are committed to check them out */
 134        memset(&state, 0, sizeof(state));
 135        state.force = 1;
 136        state.refresh_cache = 1;
 137        for (pos = 0; pos < active_nr; pos++) {
 138                struct cache_entry *ce = active_cache[pos];
 139                if (pathspec_match(pathspec, NULL, ce->name, 0)) {
 140                        if (!ce_stage(ce)) {
 141                                errs |= checkout_entry(ce, &state, NULL);
 142                                continue;
 143                        }
 144                        pos = skip_same_name(ce, pos) - 1;
 145                }
 146        }
 147
 148        if (write_cache(newfd, active_cache, active_nr) ||
 149            commit_locked_index(lock_file))
 150                die("unable to write new index file");
 151
 152        resolve_ref("HEAD", rev, 0, &flag);
 153        head = lookup_commit_reference_gently(rev, 1);
 154
 155        errs |= post_checkout_hook(head, head, 0);
 156        return errs;
 157}
 158
 159static void show_local_changes(struct object *head)
 160{
 161        struct rev_info rev;
 162        /* I think we want full paths, even if we're in a subdirectory. */
 163        init_revisions(&rev, NULL);
 164        rev.abbrev = 0;
 165        rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
 166        add_pending_object(&rev, head, NULL);
 167        run_diff_index(&rev, 0);
 168}
 169
 170static void describe_detached_head(char *msg, struct commit *commit)
 171{
 172        struct strbuf sb;
 173        strbuf_init(&sb, 0);
 174        parse_commit(commit);
 175        pretty_print_commit(CMIT_FMT_ONELINE, commit, &sb, 0, NULL, NULL, 0, 0);
 176        fprintf(stderr, "%s %s... %s\n", msg,
 177                find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf);
 178        strbuf_release(&sb);
 179}
 180
 181struct checkout_opts {
 182        int quiet;
 183        int merge;
 184        int force;
 185        int writeout_error;
 186
 187        char *new_branch;
 188        int new_branch_log;
 189        enum branch_track track;
 190};
 191
 192static int reset_tree(struct tree *tree, struct checkout_opts *o, int worktree)
 193{
 194        struct unpack_trees_options opts;
 195        struct tree_desc tree_desc;
 196
 197        memset(&opts, 0, sizeof(opts));
 198        opts.head_idx = -1;
 199        opts.update = worktree;
 200        opts.skip_unmerged = !worktree;
 201        opts.reset = 1;
 202        opts.merge = 1;
 203        opts.fn = oneway_merge;
 204        opts.verbose_update = !o->quiet;
 205        opts.src_index = &the_index;
 206        opts.dst_index = &the_index;
 207        parse_tree(tree);
 208        init_tree_desc(&tree_desc, tree->buffer, tree->size);
 209        switch (unpack_trees(1, &tree_desc, &opts)) {
 210        case -2:
 211                o->writeout_error = 1;
 212                /*
 213                 * We return 0 nevertheless, as the index is all right
 214                 * and more importantly we have made best efforts to
 215                 * update paths in the work tree, and we cannot revert
 216                 * them.
 217                 */
 218        case 0:
 219                return 0;
 220        default:
 221                return 128;
 222        }
 223}
 224
 225struct branch_info {
 226        const char *name; /* The short name used */
 227        const char *path; /* The full name of a real branch */
 228        struct commit *commit; /* The named commit */
 229};
 230
 231static void setup_branch_path(struct branch_info *branch)
 232{
 233        struct strbuf buf;
 234        strbuf_init(&buf, 0);
 235        strbuf_addstr(&buf, "refs/heads/");
 236        strbuf_addstr(&buf, branch->name);
 237        branch->path = strbuf_detach(&buf, NULL);
 238}
 239
 240static int merge_working_tree(struct checkout_opts *opts,
 241                              struct branch_info *old, struct branch_info *new)
 242{
 243        int ret;
 244        struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
 245        int newfd = hold_locked_index(lock_file, 1);
 246        read_cache();
 247
 248        if (opts->force) {
 249                ret = reset_tree(new->commit->tree, opts, 1);
 250                if (ret)
 251                        return ret;
 252        } else {
 253                struct tree_desc trees[2];
 254                struct tree *tree;
 255                struct unpack_trees_options topts;
 256
 257                memset(&topts, 0, sizeof(topts));
 258                topts.head_idx = -1;
 259                topts.src_index = &the_index;
 260                topts.dst_index = &the_index;
 261
 262                topts.msgs.not_uptodate_file = "You have local changes to '%s'; cannot switch branches.";
 263
 264                refresh_cache(REFRESH_QUIET);
 265
 266                if (unmerged_cache()) {
 267                        error("you need to resolve your current index first");
 268                        return 1;
 269                }
 270
 271                /* 2-way merge to the new branch */
 272                topts.initial_checkout = (!active_nr &&
 273                                          (old->commit == new->commit));
 274                topts.update = 1;
 275                topts.merge = 1;
 276                topts.gently = opts->merge;
 277                topts.verbose_update = !opts->quiet;
 278                topts.fn = twoway_merge;
 279                topts.dir = xcalloc(1, sizeof(*topts.dir));
 280                topts.dir->show_ignored = 1;
 281                topts.dir->exclude_per_dir = ".gitignore";
 282                tree = parse_tree_indirect(old->commit->object.sha1);
 283                init_tree_desc(&trees[0], tree->buffer, tree->size);
 284                tree = parse_tree_indirect(new->commit->object.sha1);
 285                init_tree_desc(&trees[1], tree->buffer, tree->size);
 286
 287                ret = unpack_trees(2, trees, &topts);
 288                if (ret == -1) {
 289                        /*
 290                         * Unpack couldn't do a trivial merge; either
 291                         * give up or do a real merge, depending on
 292                         * whether the merge flag was used.
 293                         */
 294                        struct tree *result;
 295                        struct tree *work;
 296                        if (!opts->merge)
 297                                return 1;
 298                        parse_commit(old->commit);
 299
 300                        /* Do more real merge */
 301
 302                        /*
 303                         * We update the index fully, then write the
 304                         * tree from the index, then merge the new
 305                         * branch with the current tree, with the old
 306                         * branch as the base. Then we reset the index
 307                         * (but not the working tree) to the new
 308                         * branch, leaving the working tree as the
 309                         * merged version, but skipping unmerged
 310                         * entries in the index.
 311                         */
 312
 313                        add_files_to_cache(NULL, NULL, 0);
 314                        work = write_tree_from_memory();
 315
 316                        ret = reset_tree(new->commit->tree, opts, 1);
 317                        if (ret)
 318                                return ret;
 319                        merge_trees(new->commit->tree, work, old->commit->tree,
 320                                    new->name, "local", &result);
 321                        ret = reset_tree(new->commit->tree, opts, 0);
 322                        if (ret)
 323                                return ret;
 324                }
 325        }
 326
 327        if (write_cache(newfd, active_cache, active_nr) ||
 328            commit_locked_index(lock_file))
 329                die("unable to write new index file");
 330
 331        if (!opts->force && !opts->quiet)
 332                show_local_changes(&new->commit->object);
 333
 334        return 0;
 335}
 336
 337static void report_tracking(struct branch_info *new)
 338{
 339        struct strbuf sb = STRBUF_INIT;
 340        struct branch *branch = branch_get(new->name);
 341
 342        if (!format_tracking_info(branch, &sb))
 343                return;
 344        fputs(sb.buf, stdout);
 345        strbuf_release(&sb);
 346}
 347
 348static void update_refs_for_switch(struct checkout_opts *opts,
 349                                   struct branch_info *old,
 350                                   struct branch_info *new)
 351{
 352        struct strbuf msg;
 353        const char *old_desc;
 354        if (opts->new_branch) {
 355                create_branch(old->name, opts->new_branch, new->name, 0,
 356                              opts->new_branch_log, opts->track);
 357                new->name = opts->new_branch;
 358                setup_branch_path(new);
 359        }
 360
 361        strbuf_init(&msg, 0);
 362        old_desc = old->name;
 363        if (!old_desc)
 364                old_desc = sha1_to_hex(old->commit->object.sha1);
 365        strbuf_addf(&msg, "checkout: moving from %s to %s",
 366                    old_desc, new->name);
 367
 368        if (new->path) {
 369                create_symref("HEAD", new->path, msg.buf);
 370                if (!opts->quiet) {
 371                        if (old->path && !strcmp(new->path, old->path))
 372                                fprintf(stderr, "Already on \"%s\"\n",
 373                                        new->name);
 374                        else
 375                                fprintf(stderr, "Switched to%s branch \"%s\"\n",
 376                                        opts->new_branch ? " a new" : "",
 377                                        new->name);
 378                }
 379        } else if (strcmp(new->name, "HEAD")) {
 380                update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
 381                           REF_NODEREF, DIE_ON_ERR);
 382                if (!opts->quiet) {
 383                        if (old->path)
 384                                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);
 385                        describe_detached_head("HEAD is now at", new->commit);
 386                }
 387        }
 388        remove_branch_state();
 389        strbuf_release(&msg);
 390        if (!opts->quiet && (new->path || !strcmp(new->name, "HEAD")))
 391                report_tracking(new);
 392}
 393
 394static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
 395{
 396        int ret = 0;
 397        struct branch_info old;
 398        unsigned char rev[20];
 399        int flag;
 400        memset(&old, 0, sizeof(old));
 401        old.path = resolve_ref("HEAD", rev, 0, &flag);
 402        old.commit = lookup_commit_reference_gently(rev, 1);
 403        if (!(flag & REF_ISSYMREF))
 404                old.path = NULL;
 405
 406        if (old.path && !prefixcmp(old.path, "refs/heads/"))
 407                old.name = old.path + strlen("refs/heads/");
 408
 409        if (!new->name) {
 410                new->name = "HEAD";
 411                new->commit = old.commit;
 412                if (!new->commit)
 413                        die("You are on a branch yet to be born");
 414                parse_commit(new->commit);
 415        }
 416
 417        /*
 418         * If we were on a detached HEAD, but we are now moving to
 419         * a new commit, we want to mention the old commit once more
 420         * to remind the user that it might be lost.
 421         */
 422        if (!opts->quiet && !old.path && new->commit != old.commit)
 423                describe_detached_head("Previous HEAD position was", old.commit);
 424
 425        if (!old.commit) {
 426                if (!opts->quiet) {
 427                        fprintf(stderr, "warning: You appear to be on a branch yet to be born.\n");
 428                        fprintf(stderr, "warning: Forcing checkout of %s.\n", new->name);
 429                }
 430                opts->force = 1;
 431        }
 432
 433        ret = merge_working_tree(opts, &old, new);
 434        if (ret)
 435                return ret;
 436
 437        update_refs_for_switch(opts, &old, new);
 438
 439        ret = post_checkout_hook(old.commit, new->commit, 1);
 440        return ret || opts->writeout_error;
 441}
 442
 443int cmd_checkout(int argc, const char **argv, const char *prefix)
 444{
 445        struct checkout_opts opts;
 446        unsigned char rev[20];
 447        const char *arg;
 448        struct branch_info new;
 449        struct tree *source_tree = NULL;
 450        struct option options[] = {
 451                OPT__QUIET(&opts.quiet),
 452                OPT_STRING('b', NULL, &opts.new_branch, "new branch", "branch"),
 453                OPT_BOOLEAN('l', NULL, &opts.new_branch_log, "log for new branch"),
 454                OPT_SET_INT('t', "track",  &opts.track, "track",
 455                        BRANCH_TRACK_EXPLICIT),
 456                OPT_BOOLEAN('f', NULL, &opts.force, "force"),
 457                OPT_BOOLEAN('m', NULL, &opts.merge, "merge"),
 458                OPT_END(),
 459        };
 460        int has_dash_dash;
 461
 462        memset(&opts, 0, sizeof(opts));
 463        memset(&new, 0, sizeof(new));
 464
 465        git_config(git_default_config, NULL);
 466
 467        opts.track = git_branch_track;
 468
 469        argc = parse_options(argc, argv, options, checkout_usage,
 470                             PARSE_OPT_KEEP_DASHDASH);
 471
 472        if (!opts.new_branch && (opts.track != git_branch_track))
 473                die("git checkout: --track and --no-track require -b");
 474
 475        if (opts.force && opts.merge)
 476                die("git checkout: -f and -m are incompatible");
 477
 478        /*
 479         * case 1: git checkout <ref> -- [<paths>]
 480         *
 481         *   <ref> must be a valid tree, everything after the '--' must be
 482         *   a path.
 483         *
 484         * case 2: git checkout -- [<paths>]
 485         *
 486         *   everything after the '--' must be paths.
 487         *
 488         * case 3: git checkout <something> [<paths>]
 489         *
 490         *   With no paths, if <something> is a commit, that is to
 491         *   switch to the branch or detach HEAD at it.
 492         *
 493         *   Otherwise <something> shall not be ambiguous.
 494         *   - If it's *only* a reference, treat it like case (1).
 495         *   - If it's only a path, treat it like case (2).
 496         *   - else: fail.
 497         *
 498         */
 499        if (argc) {
 500                if (!strcmp(argv[0], "--")) {       /* case (2) */
 501                        argv++;
 502                        argc--;
 503                        goto no_reference;
 504                }
 505
 506                arg = argv[0];
 507                has_dash_dash = (argc > 1) && !strcmp(argv[1], "--");
 508
 509                if (get_sha1(arg, rev)) {
 510                        if (has_dash_dash)          /* case (1) */
 511                                die("invalid reference: %s", arg);
 512                        goto no_reference;          /* case (3 -> 2) */
 513                }
 514
 515                /* we can't end up being in (2) anymore, eat the argument */
 516                argv++;
 517                argc--;
 518
 519                if ((new.commit = lookup_commit_reference_gently(rev, 1))) {
 520                        new.name = arg;
 521                        setup_branch_path(&new);
 522                        if (resolve_ref(new.path, rev, 1, NULL))
 523                                new.commit = lookup_commit_reference(rev);
 524                        else
 525                                new.path = NULL;
 526                        parse_commit(new.commit);
 527                        source_tree = new.commit->tree;
 528                } else
 529                        source_tree = parse_tree_indirect(rev);
 530
 531                if (!source_tree)                   /* case (1): want a tree */
 532                        die("reference is not a tree: %s", arg);
 533                if (!has_dash_dash) {/* case (3 -> 1) */
 534                        /*
 535                         * Do not complain the most common case
 536                         *      git checkout branch
 537                         * even if there happen to be a file called 'branch';
 538                         * it would be extremely annoying.
 539                         */
 540                        if (argc)
 541                                verify_non_filename(NULL, arg);
 542                }
 543                else {
 544                        argv++;
 545                        argc--;
 546                }
 547        }
 548
 549no_reference:
 550        if (argc) {
 551                const char **pathspec = get_pathspec(prefix, argv);
 552
 553                if (!pathspec)
 554                        die("invalid path specification");
 555
 556                /* Checkout paths */
 557                if (opts.new_branch || opts.force || opts.merge) {
 558                        if (argc == 1) {
 559                                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]);
 560                        } else {
 561                                die("git checkout: updating paths is incompatible with switching branches/forcing");
 562                        }
 563                }
 564
 565                return checkout_paths(source_tree, pathspec);
 566        }
 567
 568        if (opts.new_branch) {
 569                struct strbuf buf;
 570                strbuf_init(&buf, 0);
 571                strbuf_addstr(&buf, "refs/heads/");
 572                strbuf_addstr(&buf, opts.new_branch);
 573                if (!get_sha1(buf.buf, rev))
 574                        die("git checkout: branch %s already exists", opts.new_branch);
 575                if (check_ref_format(buf.buf))
 576                        die("git checkout: we do not like '%s' as a branch name.", opts.new_branch);
 577                strbuf_release(&buf);
 578        }
 579
 580        if (new.name && !new.commit) {
 581                die("Cannot switch branch to a non-commit.");
 582        }
 583
 584        return switch_branches(&opts, &new);
 585}