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
  22static const char * const git_reset_usage[] = {
  23        "git reset [--mixed | --soft | --hard | --merge] [-q] [<commit>]",
  24        "git reset [--mixed] <commit> [--] <paths>...",
  25        NULL
  26};
  27
  28enum reset_type { MIXED, SOFT, HARD, MERGE, NONE };
  29static const char *reset_type_names[] = { "mixed", "soft", "hard", "merge", NULL };
  30
  31static char *args_to_str(const char **argv)
  32{
  33        char *buf = NULL;
  34        unsigned long len, space = 0, nr = 0;
  35
  36        for (; *argv; argv++) {
  37                len = strlen(*argv);
  38                ALLOC_GROW(buf, nr + 1 + len, space);
  39                if (nr)
  40                        buf[nr++] = ' ';
  41                memcpy(buf + nr, *argv, len);
  42                nr += len;
  43        }
  44        ALLOC_GROW(buf, nr + 1, space);
  45        buf[nr] = '\0';
  46
  47        return buf;
  48}
  49
  50static inline int is_merge(void)
  51{
  52        return !access(git_path("MERGE_HEAD"), F_OK);
  53}
  54
  55static int reset_index_file(const unsigned char *sha1, int reset_type, int quiet)
  56{
  57        int i = 0;
  58        const char *args[6];
  59
  60        args[i++] = "read-tree";
  61        if (!quiet)
  62                args[i++] = "-v";
  63        switch (reset_type) {
  64        case MERGE:
  65                args[i++] = "-u";
  66                args[i++] = "-m";
  67                break;
  68        case HARD:
  69                args[i++] = "-u";
  70                /* fallthrough */
  71        default:
  72                args[i++] = "--reset";
  73        }
  74        args[i++] = sha1_to_hex(sha1);
  75        args[i] = NULL;
  76
  77        return run_command_v_opt(args, RUN_GIT_CMD);
  78}
  79
  80static void print_new_head_line(struct commit *commit)
  81{
  82        const char *hex, *body;
  83
  84        hex = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
  85        printf("HEAD is now at %s", hex);
  86        body = strstr(commit->buffer, "\n\n");
  87        if (body) {
  88                const char *eol;
  89                size_t len;
  90                body += 2;
  91                eol = strchr(body, '\n');
  92                len = eol ? eol - body : strlen(body);
  93                printf(" %.*s\n", (int) len, body);
  94        }
  95        else
  96                printf("\n");
  97}
  98
  99static int update_index_refresh(int fd, struct lock_file *index_lock, int flags)
 100{
 101        int result;
 102
 103        if (!index_lock) {
 104                index_lock = xcalloc(1, sizeof(struct lock_file));
 105                fd = hold_locked_index(index_lock, 1);
 106        }
 107
 108        if (read_cache() < 0)
 109                return error("Could not read index");
 110
 111        result = refresh_cache(flags) ? 1 : 0;
 112        if (write_cache(fd, active_cache, active_nr) ||
 113                        commit_locked_index(index_lock))
 114                return error ("Could not refresh index");
 115        return result;
 116}
 117
 118static void update_index_from_diff(struct diff_queue_struct *q,
 119                struct diff_options *opt, void *data)
 120{
 121        int i;
 122        int *discard_flag = data;
 123
 124        /* do_diff_cache() mangled the index */
 125        discard_cache();
 126        *discard_flag = 1;
 127        read_cache();
 128
 129        for (i = 0; i < q->nr; i++) {
 130                struct diff_filespec *one = q->queue[i]->one;
 131                if (one->mode) {
 132                        struct cache_entry *ce;
 133                        ce = make_cache_entry(one->mode, one->sha1, one->path,
 134                                0, 0);
 135                        if (!ce)
 136                                die("make_cache_entry failed for path '%s'",
 137                                    one->path);
 138                        add_cache_entry(ce, ADD_CACHE_OK_TO_ADD |
 139                                ADD_CACHE_OK_TO_REPLACE);
 140                } else
 141                        remove_file_from_cache(one->path);
 142        }
 143}
 144
 145static int read_from_tree(const char *prefix, const char **argv,
 146                unsigned char *tree_sha1, int refresh_flags)
 147{
 148        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
 149        int index_fd, index_was_discarded = 0;
 150        struct diff_options opt;
 151
 152        memset(&opt, 0, sizeof(opt));
 153        diff_tree_setup_paths(get_pathspec(prefix, (const char **)argv), &opt);
 154        opt.output_format = DIFF_FORMAT_CALLBACK;
 155        opt.format_callback = update_index_from_diff;
 156        opt.format_callback_data = &index_was_discarded;
 157
 158        index_fd = hold_locked_index(lock, 1);
 159        index_was_discarded = 0;
 160        read_cache();
 161        if (do_diff_cache(tree_sha1, &opt))
 162                return 1;
 163        diffcore_std(&opt);
 164        diff_flush(&opt);
 165        diff_tree_release_paths(&opt);
 166
 167        if (!index_was_discarded)
 168                /* The index is still clobbered from do_diff_cache() */
 169                discard_cache();
 170        return update_index_refresh(index_fd, lock, refresh_flags);
 171}
 172
 173static void prepend_reflog_action(const char *action, char *buf, size_t size)
 174{
 175        const char *sep = ": ";
 176        const char *rla = getenv("GIT_REFLOG_ACTION");
 177        if (!rla)
 178                rla = sep = "";
 179        if (snprintf(buf, size, "%s%s%s", rla, sep, action) >= size)
 180                warning("Reflog action message too long: %.*s...", 50, buf);
 181}
 182
 183int cmd_reset(int argc, const char **argv, const char *prefix)
 184{
 185        int i = 0, reset_type = NONE, update_ref_status = 0, quiet = 0;
 186        const char *rev = "HEAD";
 187        unsigned char sha1[20], *orig = NULL, sha1_orig[20],
 188                                *old_orig = NULL, sha1_old_orig[20];
 189        struct commit *commit;
 190        char *reflog_action, msg[1024];
 191        const struct option options[] = {
 192                OPT_SET_INT(0, "mixed", &reset_type,
 193                                                "reset HEAD and index", MIXED),
 194                OPT_SET_INT(0, "soft", &reset_type, "reset only HEAD", SOFT),
 195                OPT_SET_INT(0, "hard", &reset_type,
 196                                "reset HEAD, index and working tree", HARD),
 197                OPT_SET_INT(0, "merge", &reset_type,
 198                                "reset HEAD, index and working tree", MERGE),
 199                OPT_BOOLEAN('q', NULL, &quiet,
 200                                "disable showing new HEAD in hard reset and progress message"),
 201                OPT_END()
 202        };
 203
 204        git_config(git_default_config, NULL);
 205
 206        argc = parse_options(argc, argv, options, git_reset_usage,
 207                                                PARSE_OPT_KEEP_DASHDASH);
 208        reflog_action = args_to_str(argv);
 209        setenv("GIT_REFLOG_ACTION", reflog_action, 0);
 210
 211        /*
 212         * Possible arguments are:
 213         *
 214         * git reset [-opts] <rev> <paths>...
 215         * git reset [-opts] <rev> -- <paths>...
 216         * git reset [-opts] -- <paths>...
 217         * git reset [-opts] <paths>...
 218         *
 219         * At this point, argv[i] points immediately after [-opts].
 220         */
 221
 222        if (i < argc) {
 223                if (!strcmp(argv[i], "--")) {
 224                        i++; /* reset to HEAD, possibly with paths */
 225                } else if (i + 1 < argc && !strcmp(argv[i+1], "--")) {
 226                        rev = argv[i];
 227                        i += 2;
 228                }
 229                /*
 230                 * Otherwise, argv[i] could be either <rev> or <paths> and
 231                 * has to be unambigous.
 232                 */
 233                else if (!get_sha1(argv[i], sha1)) {
 234                        /*
 235                         * Ok, argv[i] looks like a rev; it should not
 236                         * be a filename.
 237                         */
 238                        verify_non_filename(prefix, argv[i]);
 239                        rev = argv[i++];
 240                } else {
 241                        /* Otherwise we treat this as a filename */
 242                        verify_filename(prefix, argv[i]);
 243                }
 244        }
 245
 246        if (get_sha1(rev, sha1))
 247                die("Failed to resolve '%s' as a valid ref.", rev);
 248
 249        commit = lookup_commit_reference(sha1);
 250        if (!commit)
 251                die("Could not parse object '%s'.", rev);
 252        hashcpy(sha1, commit->object.sha1);
 253
 254        /* git reset tree [--] paths... can be used to
 255         * load chosen paths from the tree into the index without
 256         * affecting the working tree nor HEAD. */
 257        if (i < argc) {
 258                if (reset_type == MIXED)
 259                        warning("--mixed option is deprecated with paths.");
 260                else if (reset_type != NONE)
 261                        die("Cannot do %s reset with paths.",
 262                                        reset_type_names[reset_type]);
 263                return read_from_tree(prefix, argv + i, sha1,
 264                                quiet ? REFRESH_QUIET : REFRESH_SAY_CHANGED);
 265        }
 266        if (reset_type == NONE)
 267                reset_type = MIXED; /* by default */
 268
 269        if (reset_type == HARD && is_bare_repository())
 270                die("hard reset makes no sense in a bare repository");
 271
 272        /* Soft reset does not touch the index file nor the working tree
 273         * at all, but requires them in a good order.  Other resets reset
 274         * the index file to the tree object we are switching to. */
 275        if (reset_type == SOFT) {
 276                if (is_merge() || read_cache() < 0 || unmerged_cache())
 277                        die("Cannot do a soft reset in the middle of a merge.");
 278        }
 279        else if (reset_index_file(sha1, reset_type, quiet))
 280                die("Could not reset index file to revision '%s'.", rev);
 281
 282        /* Any resets update HEAD to the head being switched to,
 283         * saving the previous head in ORIG_HEAD before. */
 284        if (!get_sha1("ORIG_HEAD", sha1_old_orig))
 285                old_orig = sha1_old_orig;
 286        if (!get_sha1("HEAD", sha1_orig)) {
 287                orig = sha1_orig;
 288                prepend_reflog_action("updating ORIG_HEAD", msg, sizeof(msg));
 289                update_ref(msg, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
 290        }
 291        else if (old_orig)
 292                delete_ref("ORIG_HEAD", old_orig, 0);
 293        prepend_reflog_action("updating HEAD", msg, sizeof(msg));
 294        update_ref_status = update_ref(msg, "HEAD", sha1, orig, 0, MSG_ON_ERR);
 295
 296        switch (reset_type) {
 297        case HARD:
 298                if (!update_ref_status && !quiet)
 299                        print_new_head_line(commit);
 300                break;
 301        case SOFT: /* Nothing else to do. */
 302                break;
 303        case MIXED: /* Report what has not been updated. */
 304                update_index_refresh(0, NULL,
 305                                quiet ? REFRESH_QUIET : REFRESH_SAY_CHANGED);
 306                break;
 307        }
 308
 309        remove_branch_state();
 310
 311        free(reflog_action);
 312
 313        return update_ref_status;
 314}