Andrew's git - gitweb.git/blob

   1/*
   2 * "git reset" builtin command
   3 *
   4 * Copyright (c) 2007 Carlos Rica
   5 *
   6 * Based on git-reset.sh, which is
   7 *
   8 * Copyright (c) 2005, 2006 Linus Torvalds and Junio C Hamano
   9 */
  10#include "builtin.h"
  11#include "tag.h"
  12#include "object.h"
  13#include "commit.h"
  14#include "run-command.h"
  15#include "refs.h"
  16#include "diff.h"
  17#include "diffcore.h"
  18#include "tree.h"
  19#include "branch.h"
  20#include "parse-options.h"
  21#include "unpack-trees.h"
  22#include "cache-tree.h"
  23
  24static const char * const git_reset_usage[] = {
  25        N_("git reset [--mixed | --soft | --hard | --merge | --keep] [-q] [<commit>]"),
  26        N_("git reset [-q] <commit> [--] <paths>..."),
  27        N_("git reset --patch [<commit>] [--] [<paths>...]"),
  28        NULL
  29};
  30
  31enum reset_type { MIXED, SOFT, HARD, MERGE, KEEP, NONE };
  32static const char *reset_type_names[] = {
  33        N_("mixed"), N_("soft"), N_("hard"), N_("merge"), N_("keep"), NULL
  34};
  35
  36static inline int is_merge(void)
  37{
  38        return !access(git_path("MERGE_HEAD"), F_OK);
  39}
  40
  41static int reset_index_file(const unsigned char *sha1, int reset_type, int quiet)
  42{
  43        int nr = 1;
  44        int newfd;
  45        struct tree_desc desc[2];
  46        struct tree *tree;
  47        struct unpack_trees_options opts;
  48        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
  49
  50        memset(&opts, 0, sizeof(opts));
  51        opts.head_idx = 1;
  52        opts.src_index = &the_index;
  53        opts.dst_index = &the_index;
  54        opts.fn = oneway_merge;
  55        opts.merge = 1;
  56        if (!quiet)
  57                opts.verbose_update = 1;
  58        switch (reset_type) {
  59        case KEEP:
  60        case MERGE:
  61                opts.update = 1;
  62                break;
  63        case HARD:
  64                opts.update = 1;
  65                /* fallthrough */
  66        default:
  67                opts.reset = 1;
  68        }
  69
  70        newfd = hold_locked_index(lock, 1);
  71
  72        read_cache_unmerged();
  73
  74        if (reset_type == KEEP) {
  75                unsigned char head_sha1[20];
  76                if (get_sha1("HEAD", head_sha1))
  77                        return error(_("You do not have a valid HEAD."));
  78                if (!fill_tree_descriptor(desc, head_sha1))
  79                        return error(_("Failed to find tree of HEAD."));
  80                nr++;
  81                opts.fn = twoway_merge;
  82        }
  83
  84        if (!fill_tree_descriptor(desc + nr - 1, sha1))
  85                return error(_("Failed to find tree of %s."), sha1_to_hex(sha1));
  86        if (unpack_trees(nr, desc, &opts))
  87                return -1;
  88
  89        if (reset_type == MIXED || reset_type == HARD) {
  90                tree = parse_tree_indirect(sha1);
  91                prime_cache_tree(&active_cache_tree, tree);
  92        }
  93
  94        if (write_cache(newfd, active_cache, active_nr) ||
  95            commit_locked_index(lock))
  96                return error(_("Could not write new index file."));
  97
  98        return 0;
  99}
 100
 101static void print_new_head_line(struct commit *commit)
 102{
 103        const char *hex, *body;
 104
 105        hex = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
 106        printf(_("HEAD is now at %s"), hex);
 107        body = strstr(commit->buffer, "\n\n");
 108        if (body) {
 109                const char *eol;
 110                size_t len;
 111                body += 2;
 112                eol = strchr(body, '\n');
 113                len = eol ? eol - body : strlen(body);
 114                printf(" %.*s\n", (int) len, body);
 115        }
 116        else
 117                printf("\n");
 118}
 119
 120static int update_index_refresh(int fd, struct lock_file *index_lock, int flags)
 121{
 122        if (!index_lock) {
 123                index_lock = xcalloc(1, sizeof(struct lock_file));
 124                fd = hold_locked_index(index_lock, 1);
 125        }
 126
 127        refresh_index(&the_index, (flags), NULL, NULL,
 128                      _("Unstaged changes after reset:"));
 129        if (write_cache(fd, active_cache, active_nr) ||
 130                        commit_locked_index(index_lock))
 131                return error ("Could not refresh index");
 132        return 0;
 133}
 134
 135static void update_index_from_diff(struct diff_queue_struct *q,
 136                struct diff_options *opt, void *data)
 137{
 138        int i;
 139
 140        for (i = 0; i < q->nr; i++) {
 141                struct diff_filespec *one = q->queue[i]->one;
 142                if (one->mode && !is_null_sha1(one->sha1)) {
 143                        struct cache_entry *ce;
 144                        ce = make_cache_entry(one->mode, one->sha1, one->path,
 145                                0, 0);
 146                        if (!ce)
 147                                die(_("make_cache_entry failed for path '%s'"),
 148                                    one->path);
 149                        add_cache_entry(ce, ADD_CACHE_OK_TO_ADD |
 150                                ADD_CACHE_OK_TO_REPLACE);
 151                } else
 152                        remove_file_from_cache(one->path);
 153        }
 154}
 155
 156static int read_from_tree(const char **pathspec, unsigned char *tree_sha1,
 157                          int refresh_flags)
 158{
 159        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
 160        int index_fd;
 161        struct diff_options opt;
 162
 163        memset(&opt, 0, sizeof(opt));
 164        diff_tree_setup_paths(pathspec, &opt);
 165        opt.output_format = DIFF_FORMAT_CALLBACK;
 166        opt.format_callback = update_index_from_diff;
 167
 168        index_fd = hold_locked_index(lock, 1);
 169        read_cache();
 170        if (do_diff_cache(tree_sha1, &opt))
 171                return 1;
 172        diffcore_std(&opt);
 173        diff_flush(&opt);
 174        diff_tree_release_paths(&opt);
 175
 176        return update_index_refresh(index_fd, lock, refresh_flags);
 177}
 178
 179static void set_reflog_message(struct strbuf *sb, const char *action,
 180                               const char *rev)
 181{
 182        const char *rla = getenv("GIT_REFLOG_ACTION");
 183
 184        strbuf_reset(sb);
 185        if (rla)
 186                strbuf_addf(sb, "%s: %s", rla, action);
 187        else if (rev)
 188                strbuf_addf(sb, "reset: moving to %s", rev);
 189        else
 190                strbuf_addf(sb, "reset: %s", action);
 191}
 192
 193static void die_if_unmerged_cache(int reset_type)
 194{
 195        if (is_merge() || read_cache() < 0 || unmerged_cache())
 196                die(_("Cannot do a %s reset in the middle of a merge."),
 197                    _(reset_type_names[reset_type]));
 198
 199}
 200
 201static const char **parse_args(const char **argv, const char *prefix, const char **rev_ret)
 202{
 203        const char *rev = "HEAD";
 204        unsigned char unused[20];
 205        /*
 206         * Possible arguments are:
 207         *
 208         * git reset [-opts] <rev> <paths>...
 209         * git reset [-opts] <rev> -- <paths>...
 210         * git reset [-opts] -- <paths>...
 211         * git reset [-opts] <paths>...
 212         *
 213         * At this point, argv points immediately after [-opts].
 214         */
 215
 216        if (argv[0]) {
 217                if (!strcmp(argv[0], "--")) {
 218                        argv++; /* reset to HEAD, possibly with paths */
 219                } else if (argv[1] && !strcmp(argv[1], "--")) {
 220                        rev = argv[0];
 221                        argv += 2;
 222                }
 223                /*
 224                 * Otherwise, argv[0] could be either <rev> or <paths> and
 225                 * has to be unambiguous.
 226                 */
 227                else if (!get_sha1_committish(argv[0], unused)) {
 228                        /*
 229                         * Ok, argv[0] looks like a rev; it should not
 230                         * be a filename.
 231                         */
 232                        verify_non_filename(prefix, argv[0]);
 233                        rev = *argv++;
 234                } else {
 235                        /* Otherwise we treat this as a filename */
 236                        verify_filename(prefix, argv[0], 1);
 237                }
 238        }
 239        *rev_ret = rev;
 240        return argv[0] ? get_pathspec(prefix, argv) : NULL;
 241}
 242
 243int cmd_reset(int argc, const char **argv, const char *prefix)
 244{
 245        int reset_type = NONE, update_ref_status = 0, quiet = 0;
 246        int patch_mode = 0;
 247        const char *rev;
 248        unsigned char sha1[20], *orig = NULL, sha1_orig[20],
 249                                *old_orig = NULL, sha1_old_orig[20];
 250        const char **pathspec = NULL;
 251        struct commit *commit;
 252        struct strbuf msg = STRBUF_INIT;
 253        const struct option options[] = {
 254                OPT__QUIET(&quiet, N_("be quiet, only report errors")),
 255                OPT_SET_INT(0, "mixed", &reset_type,
 256                                                N_("reset HEAD and index"), MIXED),
 257                OPT_SET_INT(0, "soft", &reset_type, N_("reset only HEAD"), SOFT),
 258                OPT_SET_INT(0, "hard", &reset_type,
 259                                N_("reset HEAD, index and working tree"), HARD),
 260                OPT_SET_INT(0, "merge", &reset_type,
 261                                N_("reset HEAD, index and working tree"), MERGE),
 262                OPT_SET_INT(0, "keep", &reset_type,
 263                                N_("reset HEAD but keep local changes"), KEEP),
 264                OPT_BOOLEAN('p', "patch", &patch_mode, N_("select hunks interactively")),
 265                OPT_END()
 266        };
 267
 268        git_config(git_default_config, NULL);
 269
 270        argc = parse_options(argc, argv, prefix, options, git_reset_usage,
 271                                                PARSE_OPT_KEEP_DASHDASH);
 272        pathspec = parse_args(argv, prefix, &rev);
 273
 274        if (get_sha1_committish(rev, sha1))
 275                die(_("Failed to resolve '%s' as a valid ref."), rev);
 276
 277        /*
 278         * NOTE: As "git reset $treeish -- $path" should be usable on
 279         * any tree-ish, this is not strictly correct. We are not
 280         * moving the HEAD to any commit; we are merely resetting the
 281         * entries in the index to that of a treeish.
 282         */
 283        commit = lookup_commit_reference(sha1);
 284        if (!commit)
 285                die(_("Could not parse object '%s'."), rev);
 286        hashcpy(sha1, commit->object.sha1);
 287
 288        if (patch_mode) {
 289                if (reset_type != NONE)
 290                        die(_("--patch is incompatible with --{hard,mixed,soft}"));
 291                return run_add_interactive(rev, "--patch=reset", pathspec);
 292        }
 293
 294        /* git reset tree [--] paths... can be used to
 295         * load chosen paths from the tree into the index without
 296         * affecting the working tree nor HEAD. */
 297        if (pathspec) {
 298                if (reset_type == MIXED)
 299                        warning(_("--mixed with paths is deprecated; use 'git reset -- <paths>' instead."));
 300                else if (reset_type != NONE)
 301                        die(_("Cannot do %s reset with paths."),
 302                                        _(reset_type_names[reset_type]));
 303        }
 304        if (reset_type == NONE)
 305                reset_type = MIXED; /* by default */
 306
 307        if (reset_type != SOFT && reset_type != MIXED)
 308                setup_work_tree();
 309
 310        if (reset_type == MIXED && is_bare_repository())
 311                die(_("%s reset is not allowed in a bare repository"),
 312                    _(reset_type_names[reset_type]));
 313
 314        if (pathspec)
 315                return read_from_tree(pathspec, sha1,
 316                                quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN);
 317
 318        /* Soft reset does not touch the index file nor the working tree
 319         * at all, but requires them in a good order.  Other resets reset
 320         * the index file to the tree object we are switching to. */
 321        if (reset_type == SOFT)
 322                die_if_unmerged_cache(reset_type);
 323        else {
 324                int err;
 325                if (reset_type == KEEP)
 326                        die_if_unmerged_cache(reset_type);
 327                err = reset_index_file(sha1, reset_type, quiet);
 328                if (reset_type == KEEP)
 329                        err = err || reset_index_file(sha1, MIXED, quiet);
 330                if (err)
 331                        die(_("Could not reset index file to revision '%s'."), rev);
 332        }
 333
 334        /* Any resets update HEAD to the head being switched to,
 335         * saving the previous head in ORIG_HEAD before. */
 336        if (!get_sha1("ORIG_HEAD", sha1_old_orig))
 337                old_orig = sha1_old_orig;
 338        if (!get_sha1("HEAD", sha1_orig)) {
 339                orig = sha1_orig;
 340                set_reflog_message(&msg, "updating ORIG_HEAD", NULL);
 341                update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
 342        }
 343        else if (old_orig)
 344                delete_ref("ORIG_HEAD", old_orig, 0);
 345        set_reflog_message(&msg, "updating HEAD", rev);
 346        update_ref_status = update_ref(msg.buf, "HEAD", sha1, orig, 0, MSG_ON_ERR);
 347
 348        switch (reset_type) {
 349        case HARD:
 350                if (!update_ref_status && !quiet)
 351                        print_new_head_line(commit);
 352                break;
 353        case SOFT: /* Nothing else to do. */
 354                break;
 355        case MIXED: /* Report what has not been updated. */
 356                update_index_refresh(0, NULL,
 357                                quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN);
 358                break;
 359        }
 360
 361        remove_branch_state();
 362
 363        strbuf_release(&msg);
 364
 365        return update_ref_status;
 366}