builtin-checkout.con commit Make git-remote a builtin (211c896)
   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)
  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        int newfd;
  71        struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
  72        newfd = hold_locked_index(lock_file, 1);
  73        read_cache();
  74
  75        read_tree_recursive(tree, "", 0, 0, pathspec, update_some);
  76
  77        if (write_cache(newfd, active_cache, active_nr) ||
  78            commit_locked_index(lock_file))
  79                die("unable to write new index file");
  80
  81        /* update the index with the given tree's info
  82         * for all args, expanding wildcards, and exit
  83         * with any non-zero return code.
  84         */
  85        return 0;
  86}
  87
  88static int checkout_paths(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
  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        resolve_ref("HEAD", rev, 0, &flag);
 120        head = lookup_commit_reference_gently(rev, 1);
 121
 122        return post_checkout_hook(head, head, 0);
 123}
 124
 125static void show_local_changes(struct object *head)
 126{
 127        struct rev_info rev;
 128        /* I think we want full paths, even if we're in a subdirectory. */
 129        init_revisions(&rev, NULL);
 130        rev.abbrev = 0;
 131        rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
 132        add_pending_object(&rev, head, NULL);
 133        run_diff_index(&rev, 0);
 134}
 135
 136static void describe_detached_head(char *msg, struct commit *commit)
 137{
 138        struct strbuf sb;
 139        strbuf_init(&sb, 0);
 140        parse_commit(commit);
 141        pretty_print_commit(CMIT_FMT_ONELINE, commit, &sb, 0, "", "", 0, 0);
 142        fprintf(stderr, "%s %s... %s\n", msg,
 143                find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf);
 144        strbuf_release(&sb);
 145}
 146
 147static int reset_to_new(struct tree *tree, int quiet)
 148{
 149        struct unpack_trees_options opts;
 150        struct tree_desc tree_desc;
 151        memset(&opts, 0, sizeof(opts));
 152        opts.head_idx = -1;
 153        opts.update = 1;
 154        opts.reset = 1;
 155        opts.merge = 1;
 156        opts.fn = oneway_merge;
 157        opts.verbose_update = !quiet;
 158        parse_tree(tree);
 159        init_tree_desc(&tree_desc, tree->buffer, tree->size);
 160        if (unpack_trees(1, &tree_desc, &opts))
 161                return 128;
 162        return 0;
 163}
 164
 165static void reset_clean_to_new(struct tree *tree, int quiet)
 166{
 167        struct unpack_trees_options opts;
 168        struct tree_desc tree_desc;
 169        memset(&opts, 0, sizeof(opts));
 170        opts.head_idx = -1;
 171        opts.skip_unmerged = 1;
 172        opts.reset = 1;
 173        opts.merge = 1;
 174        opts.fn = oneway_merge;
 175        opts.verbose_update = !quiet;
 176        parse_tree(tree);
 177        init_tree_desc(&tree_desc, tree->buffer, tree->size);
 178        if (unpack_trees(1, &tree_desc, &opts))
 179                exit(128);
 180}
 181
 182struct checkout_opts {
 183        int quiet;
 184        int merge;
 185        int force;
 186
 187        char *new_branch;
 188        int new_branch_log;
 189        enum branch_track track;
 190};
 191
 192struct branch_info {
 193        const char *name; /* The short name used */
 194        const char *path; /* The full name of a real branch */
 195        struct commit *commit; /* The named commit */
 196};
 197
 198static void setup_branch_path(struct branch_info *branch)
 199{
 200        struct strbuf buf;
 201        strbuf_init(&buf, 0);
 202        strbuf_addstr(&buf, "refs/heads/");
 203        strbuf_addstr(&buf, branch->name);
 204        branch->path = strbuf_detach(&buf, NULL);
 205}
 206
 207static int merge_working_tree(struct checkout_opts *opts,
 208                              struct branch_info *old, struct branch_info *new)
 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                        error("you need to resolve your current index first");
 230                        return 1;
 231                }
 232
 233                /* 2-way merge to the new branch */
 234                topts.update = 1;
 235                topts.merge = 1;
 236                topts.gently = opts->merge;
 237                topts.verbose_update = !opts->quiet;
 238                topts.fn = twoway_merge;
 239                topts.dir = xcalloc(1, sizeof(*topts.dir));
 240                topts.dir->show_ignored = 1;
 241                topts.dir->exclude_per_dir = ".gitignore";
 242                tree = parse_tree_indirect(old->commit->object.sha1);
 243                init_tree_desc(&trees[0], tree->buffer, tree->size);
 244                tree = parse_tree_indirect(new->commit->object.sha1);
 245                init_tree_desc(&trees[1], tree->buffer, tree->size);
 246
 247                if (unpack_trees(2, trees, &topts)) {
 248                        /*
 249                         * Unpack couldn't do a trivial merge; either
 250                         * give up or do a real merge, depending on
 251                         * whether the merge flag was used.
 252                         */
 253                        struct tree *result;
 254                        struct tree *work;
 255                        if (!opts->merge)
 256                                return 1;
 257                        parse_commit(old->commit);
 258
 259                        /* Do more real merge */
 260
 261                        /*
 262                         * We update the index fully, then write the
 263                         * tree from the index, then merge the new
 264                         * branch with the current tree, with the old
 265                         * branch as the base. Then we reset the index
 266                         * (but not the working tree) to the new
 267                         * branch, leaving the working tree as the
 268                         * merged version, but skipping unmerged
 269                         * entries in the index.
 270                         */
 271
 272                        add_files_to_cache(0, NULL, NULL);
 273                        work = write_tree_from_memory();
 274
 275                        ret = reset_to_new(new->commit->tree, opts->quiet);
 276                        if (ret)
 277                                return ret;
 278                        merge_trees(new->commit->tree, work, old->commit->tree,
 279                                    new->name, "local", &result);
 280                        reset_clean_to_new(new->commit->tree, opts->quiet);
 281                }
 282        }
 283
 284        if (write_cache(newfd, active_cache, active_nr) ||
 285            commit_locked_index(lock_file))
 286                die("unable to write new index file");
 287
 288        if (!opts->force)
 289                show_local_changes(&new->commit->object);
 290
 291        return 0;
 292}
 293
 294static void report_tracking(struct branch_info *new, struct checkout_opts *opts)
 295{
 296        /*
 297         * We have switched to a new branch; is it building on
 298         * top of another branch, and if so does that other branch
 299         * have changes we do not have yet?
 300         */
 301        char *base;
 302        unsigned char sha1[20];
 303        struct commit *ours, *theirs;
 304        char symmetric[84];
 305        struct rev_info revs;
 306        const char *rev_argv[10];
 307        int rev_argc;
 308        int num_ours, num_theirs;
 309        const char *remote_msg;
 310        struct branch *branch = branch_get(new->name);
 311
 312        /*
 313         * Nothing to report unless we are marked to build on top of
 314         * somebody else.
 315         */
 316        if (!branch || !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
 317                return;
 318
 319        /*
 320         * If what we used to build on no longer exists, there is
 321         * nothing to report.
 322         */
 323        base = branch->merge[0]->dst;
 324        if (!resolve_ref(base, sha1, 1, NULL))
 325                return;
 326
 327        theirs = lookup_commit(sha1);
 328        ours = new->commit;
 329        if (!hashcmp(sha1, ours->object.sha1))
 330                return; /* we are the same */
 331
 332        /* Run "rev-list --left-right ours...theirs" internally... */
 333        rev_argc = 0;
 334        rev_argv[rev_argc++] = NULL;
 335        rev_argv[rev_argc++] = "--left-right";
 336        rev_argv[rev_argc++] = symmetric;
 337        rev_argv[rev_argc++] = "--";
 338        rev_argv[rev_argc] = NULL;
 339
 340        strcpy(symmetric, sha1_to_hex(ours->object.sha1));
 341        strcpy(symmetric + 40, "...");
 342        strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
 343
 344        init_revisions(&revs, NULL);
 345        setup_revisions(rev_argc, rev_argv, &revs, NULL);
 346        prepare_revision_walk(&revs);
 347
 348        /* ... and count the commits on each side. */
 349        num_ours = 0;
 350        num_theirs = 0;
 351        while (1) {
 352                struct commit *c = get_revision(&revs);
 353                if (!c)
 354                        break;
 355                if (c->object.flags & SYMMETRIC_LEFT)
 356                        num_ours++;
 357                else
 358                        num_theirs++;
 359        }
 360
 361        if (!prefixcmp(base, "refs/remotes/")) {
 362                remote_msg = " remote";
 363                base += strlen("refs/remotes/");
 364        } else {
 365                remote_msg = "";
 366        }
 367
 368        if (!num_theirs)
 369                printf("Your branch is ahead of the tracked%s branch '%s' "
 370                       "by %d commit%s.\n",
 371                       remote_msg, base,
 372                       num_ours, (num_ours == 1) ? "" : "s");
 373        else if (!num_ours)
 374                printf("Your branch is behind the tracked%s branch '%s' "
 375                       "by %d commit%s,\n"
 376                       "and can be fast-forwarded.\n",
 377                       remote_msg, base,
 378                       num_theirs, (num_theirs == 1) ? "" : "s");
 379        else
 380                printf("Your branch and the tracked%s branch '%s' "
 381                       "have diverged,\nand respectively "
 382                       "have %d and %d different commit(s) each.\n",
 383                       remote_msg, base,
 384                       num_ours, num_theirs);
 385}
 386
 387static void update_refs_for_switch(struct checkout_opts *opts,
 388                                   struct branch_info *old,
 389                                   struct branch_info *new)
 390{
 391        struct strbuf msg;
 392        const char *old_desc;
 393        if (opts->new_branch) {
 394                create_branch(old->name, opts->new_branch, new->name, 0,
 395                              opts->new_branch_log, opts->track);
 396                new->name = opts->new_branch;
 397                setup_branch_path(new);
 398        }
 399
 400        strbuf_init(&msg, 0);
 401        old_desc = old->name;
 402        if (!old_desc)
 403                old_desc = sha1_to_hex(old->commit->object.sha1);
 404        strbuf_addf(&msg, "checkout: moving from %s to %s",
 405                    old_desc, new->name);
 406
 407        if (new->path) {
 408                create_symref("HEAD", new->path, msg.buf);
 409                if (!opts->quiet) {
 410                        if (old->path && !strcmp(new->path, old->path))
 411                                fprintf(stderr, "Already on \"%s\"\n",
 412                                        new->name);
 413                        else
 414                                fprintf(stderr, "Switched to%s branch \"%s\"\n",
 415                                        opts->new_branch ? " a new" : "",
 416                                        new->name);
 417                }
 418        } else if (strcmp(new->name, "HEAD")) {
 419                update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
 420                           REF_NODEREF, DIE_ON_ERR);
 421                if (!opts->quiet) {
 422                        if (old->path)
 423                                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);
 424                        describe_detached_head("HEAD is now at", new->commit);
 425                }
 426        }
 427        remove_branch_state();
 428        strbuf_release(&msg);
 429        if (!opts->quiet && (new->path || !strcmp(new->name, "HEAD")))
 430                report_tracking(new, opts);
 431}
 432
 433static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
 434{
 435        int ret = 0;
 436        struct branch_info old;
 437        unsigned char rev[20];
 438        int flag;
 439        memset(&old, 0, sizeof(old));
 440        old.path = resolve_ref("HEAD", rev, 0, &flag);
 441        old.commit = lookup_commit_reference_gently(rev, 1);
 442        if (!(flag & REF_ISSYMREF))
 443                old.path = NULL;
 444
 445        if (old.path && !prefixcmp(old.path, "refs/heads/"))
 446                old.name = old.path + strlen("refs/heads/");
 447
 448        if (!new->name) {
 449                new->name = "HEAD";
 450                new->commit = old.commit;
 451                if (!new->commit)
 452                        die("You are on a branch yet to be born");
 453                parse_commit(new->commit);
 454        }
 455
 456        /*
 457         * If the new thing isn't a branch and isn't HEAD and we're
 458         * not starting a new branch, and we want messages, and we
 459         * weren't on a branch, and we're moving to a new commit,
 460         * describe the old commit.
 461         */
 462        if (!new->path && strcmp(new->name, "HEAD") && !opts->new_branch &&
 463            !opts->quiet && !old.path && new->commit != old.commit)
 464                describe_detached_head("Previous HEAD position was", old.commit);
 465
 466        if (!old.commit) {
 467                if (!opts->quiet) {
 468                        fprintf(stderr, "warning: You appear to be on a branch yet to be born.\n");
 469                        fprintf(stderr, "warning: Forcing checkout of %s.\n", new->name);
 470                }
 471                opts->force = 1;
 472        }
 473
 474        ret = merge_working_tree(opts, &old, new);
 475        if (ret)
 476                return ret;
 477
 478        update_refs_for_switch(opts, &old, new);
 479
 480        return post_checkout_hook(old.commit, new->commit, 1);
 481}
 482
 483static int git_checkout_config(const char *var, const char *value)
 484{
 485        return git_default_config(var, value);
 486}
 487
 488int cmd_checkout(int argc, const char **argv, const char *prefix)
 489{
 490        struct checkout_opts opts;
 491        unsigned char rev[20];
 492        const char *arg;
 493        struct branch_info new;
 494        struct tree *source_tree = NULL;
 495        struct option options[] = {
 496                OPT__QUIET(&opts.quiet),
 497                OPT_STRING('b', NULL, &opts.new_branch, "new branch", "branch"),
 498                OPT_BOOLEAN('l', NULL, &opts.new_branch_log, "log for new branch"),
 499                OPT_SET_INT( 0 , "track",  &opts.track, "track",
 500                        BRANCH_TRACK_EXPLICIT),
 501                OPT_BOOLEAN('f', NULL, &opts.force, "force"),
 502                OPT_BOOLEAN('m', NULL, &opts.merge, "merge"),
 503                OPT_END(),
 504        };
 505
 506        memset(&opts, 0, sizeof(opts));
 507        memset(&new, 0, sizeof(new));
 508
 509        git_config(git_checkout_config);
 510
 511        opts.track = git_branch_track;
 512
 513        argc = parse_options(argc, argv, options, checkout_usage, 0);
 514        if (argc) {
 515                arg = argv[0];
 516                if (get_sha1(arg, rev))
 517                        ;
 518                else if ((new.commit = lookup_commit_reference_gently(rev, 1))) {
 519                        new.name = arg;
 520                        setup_branch_path(&new);
 521                        if (resolve_ref(new.path, rev, 1, NULL))
 522                                new.commit = lookup_commit_reference(rev);
 523                        else
 524                                new.path = NULL;
 525                        parse_commit(new.commit);
 526                        source_tree = new.commit->tree;
 527                        argv++;
 528                        argc--;
 529                } else if ((source_tree = parse_tree_indirect(rev))) {
 530                        argv++;
 531                        argc--;
 532                }
 533        }
 534
 535        if (argc && !strcmp(argv[0], "--")) {
 536                argv++;
 537                argc--;
 538        }
 539
 540        if (!opts.new_branch && (opts.track != git_branch_track))
 541                die("git checkout: --track and --no-track require -b");
 542
 543        if (opts.force && opts.merge)
 544                die("git checkout: -f and -m are incompatible");
 545
 546        if (argc) {
 547                const char **pathspec = get_pathspec(prefix, argv);
 548                /* Checkout paths */
 549                if (opts.new_branch || opts.force || opts.merge) {
 550                        if (argc == 1) {
 551                                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]);
 552                        } else {
 553                                die("git checkout: updating paths is incompatible with switching branches/forcing");
 554                        }
 555                }
 556
 557                if (source_tree)
 558                        read_tree_some(source_tree, pathspec);
 559                else
 560                        read_cache();
 561                return checkout_paths(pathspec);
 562        }
 563
 564        if (new.name && !new.commit) {
 565                die("Cannot switch branch to a non-commit.");
 566        }
 567
 568        return switch_branches(&opts, &new);
 569}