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 "cache.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        "git reset [--mixed | --soft | --hard | --merge] [-q] [<commit>]",
  26        "git reset [-q] <commit> [--] <paths>...",
  27        "git reset --patch [<commit>] [--] [<paths>...]",
  28        NULL
  29};
  30
  31enum reset_type { MIXED, SOFT, HARD, MERGE, NONE };
  32static const char *reset_type_names[] = { "mixed", "soft", "hard", "merge", NULL };
  33
  34static char *args_to_str(const char **argv)
  35{
  36        char *buf = NULL;
  37        unsigned long len, space = 0, nr = 0;
  38
  39        for (; *argv; argv++) {
  40                len = strlen(*argv);
  41                ALLOC_GROW(buf, nr + 1 + len, space);
  42                if (nr)
  43                        buf[nr++] = ' ';
  44                memcpy(buf + nr, *argv, len);
  45                nr += len;
  46        }
  47        ALLOC_GROW(buf, nr + 1, space);
  48        buf[nr] = '\0';
  49
  50        return buf;
  51}
  52
  53static inline int is_merge(void)
  54{
  55        return !access(git_path("MERGE_HEAD"), F_OK);
  56}
  57
  58static int reset_index_file(const unsigned char *sha1, int reset_type, int quiet)
  59{
  60        int nr = 1;
  61        int newfd;
  62        struct tree_desc desc[2];
  63        struct unpack_trees_options opts;
  64        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
  65
  66        memset(&opts, 0, sizeof(opts));
  67        opts.head_idx = 1;
  68        opts.src_index = &the_index;
  69        opts.dst_index = &the_index;
  70        opts.fn = oneway_merge;
  71        opts.merge = 1;
  72        if (!quiet)
  73                opts.verbose_update = 1;
  74        switch (reset_type) {
  75        case MERGE:
  76                opts.update = 1;
  77                break;
  78        case HARD:
  79                opts.update = 1;
  80                /* fallthrough */
  81        default:
  82                opts.reset = 1;
  83        }
  84
  85        newfd = hold_locked_index(lock, 1);
  86
  87        read_cache_unmerged();
  88
  89        if (!fill_tree_descriptor(desc + nr - 1, sha1))
  90                return error("Failed to find tree of %s.", sha1_to_hex(sha1));
  91        if (unpack_trees(nr, desc, &opts))
  92                return -1;
  93        if (write_cache(newfd, active_cache, active_nr) ||
  94            commit_locked_index(lock))
  95                return error("Could not write new index file.");
  96
  97        return 0;
  98}
  99
 100static void print_new_head_line(struct commit *commit)
 101{
 102        const char *hex, *body;
 103
 104        hex = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
 105        printf("HEAD is now at %s", hex);
 106        body = strstr(commit->buffer, "\n\n");
 107        if (body) {
 108                const char *eol;
 109                size_t len;
 110                body += 2;
 111                eol = strchr(body, '\n');
 112                len = eol ? eol - body : strlen(body);
 113                printf(" %.*s\n", (int) len, body);
 114        }
 115        else
 116                printf("\n");
 117}
 118
 119static int update_index_refresh(int fd, struct lock_file *index_lock, int flags)
 120{
 121        int result;
 122
 123        if (!index_lock) {
 124                index_lock = xcalloc(1, sizeof(struct lock_file));
 125                fd = hold_locked_index(index_lock, 1);
 126        }
 127
 128        if (read_cache() < 0)
 129                return error("Could not read index");
 130
 131        result = refresh_index(&the_index, (flags), NULL, NULL,
 132                               "Unstaged changes after reset:") ? 1 : 0;
 133        if (write_cache(fd, active_cache, active_nr) ||
 134                        commit_locked_index(index_lock))
 135                return error ("Could not refresh index");
 136        return result;
 137}
 138
 139static void update_index_from_diff(struct diff_queue_struct *q,
 140                struct diff_options *opt, void *data)
 141{
 142        int i;
 143        int *discard_flag = data;
 144
 145        /* do_diff_cache() mangled the index */
 146        discard_cache();
 147        *discard_flag = 1;
 148        read_cache();
 149
 150        for (i = 0; i < q->nr; i++) {
 151                struct diff_filespec *one = q->queue[i]->one;
 152                if (one->mode) {
 153                        struct cache_entry *ce;
 154                        ce = make_cache_entry(one->mode, one->sha1, one->path,
 155                                0, 0);
 156                        if (!ce)
 157                                die("make_cache_entry failed for path '%s'",
 158                                    one->path);
 159                        add_cache_entry(ce, ADD_CACHE_OK_TO_ADD |
 160                                ADD_CACHE_OK_TO_REPLACE);
 161                } else
 162                        remove_file_from_cache(one->path);
 163        }
 164}
 165
 166static int interactive_reset(const char *revision, const char **argv,
 167                             const char *prefix)
 168{
 169        const char **pathspec = NULL;
 170
 171        if (*argv)
 172                pathspec = get_pathspec(prefix, argv);
 173
 174        return run_add_interactive(revision, "--patch=reset", pathspec);
 175}
 176
 177static int read_from_tree(const char *prefix, const char **argv,
 178                unsigned char *tree_sha1, int refresh_flags)
 179{
 180        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
 181        int index_fd, index_was_discarded = 0;
 182        struct diff_options opt;
 183
 184        memset(&opt, 0, sizeof(opt));
 185        diff_tree_setup_paths(get_pathspec(prefix, (const char **)argv), &opt);
 186        opt.output_format = DIFF_FORMAT_CALLBACK;
 187        opt.format_callback = update_index_from_diff;
 188        opt.format_callback_data = &index_was_discarded;
 189
 190        index_fd = hold_locked_index(lock, 1);
 191        index_was_discarded = 0;
 192        read_cache();
 193        if (do_diff_cache(tree_sha1, &opt))
 194                return 1;
 195        diffcore_std(&opt);
 196        diff_flush(&opt);
 197        diff_tree_release_paths(&opt);
 198
 199        if (!index_was_discarded)
 200                /* The index is still clobbered from do_diff_cache() */
 201                discard_cache();
 202        return update_index_refresh(index_fd, lock, refresh_flags);
 203}
 204
 205static void prepend_reflog_action(const char *action, char *buf, size_t size)
 206{
 207        const char *sep = ": ";
 208        const char *rla = getenv("GIT_REFLOG_ACTION");
 209        if (!rla)
 210                rla = sep = "";
 211        if (snprintf(buf, size, "%s%s%s", rla, sep, action) >= size)
 212                warning("Reflog action message too long: %.*s...", 50, buf);
 213}
 214
 215int cmd_reset(int argc, const char **argv, const char *prefix)
 216{
 217        int i = 0, reset_type = NONE, update_ref_status = 0, quiet = 0;
 218        int patch_mode = 0;
 219        const char *rev = "HEAD";
 220        unsigned char sha1[20], *orig = NULL, sha1_orig[20],
 221                                *old_orig = NULL, sha1_old_orig[20];
 222        struct commit *commit;
 223        char *reflog_action, msg[1024];
 224        const struct option options[] = {
 225                OPT__QUIET(&quiet),
 226                OPT_SET_INT(0, "mixed", &reset_type,
 227                                                "reset HEAD and index", MIXED),
 228                OPT_SET_INT(0, "soft", &reset_type, "reset only HEAD", SOFT),
 229                OPT_SET_INT(0, "hard", &reset_type,
 230                                "reset HEAD, index and working tree", HARD),
 231                OPT_SET_INT(0, "merge", &reset_type,
 232                                "reset HEAD, index and working tree", MERGE),
 233                OPT_BOOLEAN('p', "patch", &patch_mode, "select hunks interactively"),
 234                OPT_END()
 235        };
 236
 237        git_config(git_default_config, NULL);
 238
 239        argc = parse_options(argc, argv, prefix, options, git_reset_usage,
 240                                                PARSE_OPT_KEEP_DASHDASH);
 241        reflog_action = args_to_str(argv);
 242        setenv("GIT_REFLOG_ACTION", reflog_action, 0);
 243
 244        /*
 245         * Possible arguments are:
 246         *
 247         * git reset [-opts] <rev> <paths>...
 248         * git reset [-opts] <rev> -- <paths>...
 249         * git reset [-opts] -- <paths>...
 250         * git reset [-opts] <paths>...
 251         *
 252         * At this point, argv[i] points immediately after [-opts].
 253         */
 254
 255        if (i < argc) {
 256                if (!strcmp(argv[i], "--")) {
 257                        i++; /* reset to HEAD, possibly with paths */
 258                } else if (i + 1 < argc && !strcmp(argv[i+1], "--")) {
 259                        rev = argv[i];
 260                        i += 2;
 261                }
 262                /*
 263                 * Otherwise, argv[i] could be either <rev> or <paths> and
 264                 * has to be unambiguous.
 265                 */
 266                else if (!get_sha1(argv[i], sha1)) {
 267                        /*
 268                         * Ok, argv[i] looks like a rev; it should not
 269                         * be a filename.
 270                         */
 271                        verify_non_filename(prefix, argv[i]);
 272                        rev = argv[i++];
 273                } else {
 274                        /* Otherwise we treat this as a filename */
 275                        verify_filename(prefix, argv[i]);
 276                }
 277        }
 278
 279        if (get_sha1(rev, sha1))
 280                die("Failed to resolve '%s' as a valid ref.", rev);
 281
 282        commit = lookup_commit_reference(sha1);
 283        if (!commit)
 284                die("Could not parse object '%s'.", rev);
 285        hashcpy(sha1, commit->object.sha1);
 286
 287        if (patch_mode) {
 288                if (reset_type != NONE)
 289                        die("--patch is incompatible with --{hard,mixed,soft}");
 290                return interactive_reset(rev, argv + i, prefix);
 291        }
 292
 293        /* git reset tree [--] paths... can be used to
 294         * load chosen paths from the tree into the index without
 295         * affecting the working tree nor HEAD. */
 296        if (i < argc) {
 297                if (reset_type == MIXED)
 298                        warning("--mixed option is deprecated with paths.");
 299                else if (reset_type != NONE)
 300                        die("Cannot do %s reset with paths.",
 301                                        reset_type_names[reset_type]);
 302                return read_from_tree(prefix, argv + i, sha1,
 303                                quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN);
 304        }
 305        if (reset_type == NONE)
 306                reset_type = MIXED; /* by default */
 307
 308        if (reset_type == HARD || reset_type == MERGE)
 309                setup_work_tree();
 310
 311        if (reset_type == MIXED && is_bare_repository())
 312                die("%s reset is not allowed in a bare repository",
 313                    reset_type_names[reset_type]);
 314
 315        /* Soft reset does not touch the index file nor the working tree
 316         * at all, but requires them in a good order.  Other resets reset
 317         * the index file to the tree object we are switching to. */
 318        if (reset_type == SOFT) {
 319                if (is_merge() || read_cache() < 0 || unmerged_cache())
 320                        die("Cannot do a soft reset in the middle of a merge.");
 321        }
 322        else if (reset_index_file(sha1, reset_type, quiet))
 323                die("Could not reset index file to revision '%s'.", rev);
 324
 325        /* Any resets update HEAD to the head being switched to,
 326         * saving the previous head in ORIG_HEAD before. */
 327        if (!get_sha1("ORIG_HEAD", sha1_old_orig))
 328                old_orig = sha1_old_orig;
 329        if (!get_sha1("HEAD", sha1_orig)) {
 330                orig = sha1_orig;
 331                prepend_reflog_action("updating ORIG_HEAD", msg, sizeof(msg));
 332                update_ref(msg, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
 333        }
 334        else if (old_orig)
 335                delete_ref("ORIG_HEAD", old_orig, 0);
 336        prepend_reflog_action("updating HEAD", msg, sizeof(msg));
 337        update_ref_status = update_ref(msg, "HEAD", sha1, orig, 0, MSG_ON_ERR);
 338
 339        switch (reset_type) {
 340        case HARD:
 341                if (!update_ref_status && !quiet)
 342                        print_new_head_line(commit);
 343                break;
 344        case SOFT: /* Nothing else to do. */
 345                break;
 346        case MIXED: /* Report what has not been updated. */
 347                update_index_refresh(0, NULL,
 348                                quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN);
 349                break;
 350        }
 351
 352        remove_branch_state();
 353
 354        free(reflog_action);
 355
 356        return update_ref_status;
 357}