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_index(&the_index, (flags), NULL, NULL,
 112                               "Unstaged changes after reset:") ? 1 : 0;
 113        if (write_cache(fd, active_cache, active_nr) ||
 114                        commit_locked_index(index_lock))
 115                return error ("Could not refresh index");
 116        return result;
 117}
 118
 119static void update_index_from_diff(struct diff_queue_struct *q,
 120                struct diff_options *opt, void *data)
 121{
 122        int i;
 123        int *discard_flag = data;
 124
 125        /* do_diff_cache() mangled the index */
 126        discard_cache();
 127        *discard_flag = 1;
 128        read_cache();
 129
 130        for (i = 0; i < q->nr; i++) {
 131                struct diff_filespec *one = q->queue[i]->one;
 132                if (one->mode) {
 133                        struct cache_entry *ce;
 134                        ce = make_cache_entry(one->mode, one->sha1, one->path,
 135                                0, 0);
 136                        if (!ce)
 137                                die("make_cache_entry failed for path '%s'",
 138                                    one->path);
 139                        add_cache_entry(ce, ADD_CACHE_OK_TO_ADD |
 140                                ADD_CACHE_OK_TO_REPLACE);
 141                } else
 142                        remove_file_from_cache(one->path);
 143        }
 144}
 145
 146static int interactive_reset(const char *revision, const char **argv,
 147                             const char *prefix)
 148{
 149        const char **pathspec = NULL;
 150
 151        if (*argv)
 152                pathspec = get_pathspec(prefix, argv);
 153
 154        return run_add_interactive(revision, "--patch=reset", pathspec);
 155}
 156
 157static int read_from_tree(const char *prefix, const char **argv,
 158                unsigned char *tree_sha1, int refresh_flags)
 159{
 160        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
 161        int index_fd, index_was_discarded = 0;
 162        struct diff_options opt;
 163
 164        memset(&opt, 0, sizeof(opt));
 165        diff_tree_setup_paths(get_pathspec(prefix, (const char **)argv), &opt);
 166        opt.output_format = DIFF_FORMAT_CALLBACK;
 167        opt.format_callback = update_index_from_diff;
 168        opt.format_callback_data = &index_was_discarded;
 169
 170        index_fd = hold_locked_index(lock, 1);
 171        index_was_discarded = 0;
 172        read_cache();
 173        if (do_diff_cache(tree_sha1, &opt))
 174                return 1;
 175        diffcore_std(&opt);
 176        diff_flush(&opt);
 177        diff_tree_release_paths(&opt);
 178
 179        if (!index_was_discarded)
 180                /* The index is still clobbered from do_diff_cache() */
 181                discard_cache();
 182        return update_index_refresh(index_fd, lock, refresh_flags);
 183}
 184
 185static void prepend_reflog_action(const char *action, char *buf, size_t size)
 186{
 187        const char *sep = ": ";
 188        const char *rla = getenv("GIT_REFLOG_ACTION");
 189        if (!rla)
 190                rla = sep = "";
 191        if (snprintf(buf, size, "%s%s%s", rla, sep, action) >= size)
 192                warning("Reflog action message too long: %.*s...", 50, buf);
 193}
 194
 195int cmd_reset(int argc, const char **argv, const char *prefix)
 196{
 197        int i = 0, reset_type = NONE, update_ref_status = 0, quiet = 0;
 198        int patch_mode = 0;
 199        const char *rev = "HEAD";
 200        unsigned char sha1[20], *orig = NULL, sha1_orig[20],
 201                                *old_orig = NULL, sha1_old_orig[20];
 202        struct commit *commit;
 203        char *reflog_action, msg[1024];
 204        const struct option options[] = {
 205                OPT__QUIET(&quiet),
 206                OPT_SET_INT(0, "mixed", &reset_type,
 207                                                "reset HEAD and index", MIXED),
 208                OPT_SET_INT(0, "soft", &reset_type, "reset only HEAD", SOFT),
 209                OPT_SET_INT(0, "hard", &reset_type,
 210                                "reset HEAD, index and working tree", HARD),
 211                OPT_SET_INT(0, "merge", &reset_type,
 212                                "reset HEAD, index and working tree", MERGE),
 213                OPT_BOOLEAN('p', "patch", &patch_mode, "select hunks interactively"),
 214                OPT_END()
 215        };
 216
 217        git_config(git_default_config, NULL);
 218
 219        argc = parse_options(argc, argv, prefix, options, git_reset_usage,
 220                                                PARSE_OPT_KEEP_DASHDASH);
 221        reflog_action = args_to_str(argv);
 222        setenv("GIT_REFLOG_ACTION", reflog_action, 0);
 223
 224        /*
 225         * Possible arguments are:
 226         *
 227         * git reset [-opts] <rev> <paths>...
 228         * git reset [-opts] <rev> -- <paths>...
 229         * git reset [-opts] -- <paths>...
 230         * git reset [-opts] <paths>...
 231         *
 232         * At this point, argv[i] points immediately after [-opts].
 233         */
 234
 235        if (i < argc) {
 236                if (!strcmp(argv[i], "--")) {
 237                        i++; /* reset to HEAD, possibly with paths */
 238                } else if (i + 1 < argc && !strcmp(argv[i+1], "--")) {
 239                        rev = argv[i];
 240                        i += 2;
 241                }
 242                /*
 243                 * Otherwise, argv[i] could be either <rev> or <paths> and
 244                 * has to be unambiguous.
 245                 */
 246                else if (!get_sha1(argv[i], sha1)) {
 247                        /*
 248                         * Ok, argv[i] looks like a rev; it should not
 249                         * be a filename.
 250                         */
 251                        verify_non_filename(prefix, argv[i]);
 252                        rev = argv[i++];
 253                } else {
 254                        /* Otherwise we treat this as a filename */
 255                        verify_filename(prefix, argv[i]);
 256                }
 257        }
 258
 259        if (get_sha1(rev, sha1))
 260                die("Failed to resolve '%s' as a valid ref.", rev);
 261
 262        commit = lookup_commit_reference(sha1);
 263        if (!commit)
 264                die("Could not parse object '%s'.", rev);
 265        hashcpy(sha1, commit->object.sha1);
 266
 267        if (patch_mode) {
 268                if (reset_type != NONE)
 269                        die("--patch is incompatible with --{hard,mixed,soft}");
 270                return interactive_reset(rev, argv + i, prefix);
 271        }
 272
 273        /* git reset tree [--] paths... can be used to
 274         * load chosen paths from the tree into the index without
 275         * affecting the working tree nor HEAD. */
 276        if (i < argc) {
 277                if (reset_type == MIXED)
 278                        warning("--mixed option is deprecated with paths.");
 279                else if (reset_type != NONE)
 280                        die("Cannot do %s reset with paths.",
 281                                        reset_type_names[reset_type]);
 282                return read_from_tree(prefix, argv + i, sha1,
 283                                quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN);
 284        }
 285        if (reset_type == NONE)
 286                reset_type = MIXED; /* by default */
 287
 288        if (reset_type == HARD || reset_type == MERGE)
 289                setup_work_tree();
 290
 291        /* Soft reset does not touch the index file nor the working tree
 292         * at all, but requires them in a good order.  Other resets reset
 293         * the index file to the tree object we are switching to. */
 294        if (reset_type == SOFT) {
 295                if (is_merge() || read_cache() < 0 || unmerged_cache())
 296                        die("Cannot do a soft reset in the middle of a merge.");
 297        }
 298        else if (reset_index_file(sha1, reset_type, quiet))
 299                die("Could not reset index file to revision '%s'.", rev);
 300
 301        /* Any resets update HEAD to the head being switched to,
 302         * saving the previous head in ORIG_HEAD before. */
 303        if (!get_sha1("ORIG_HEAD", sha1_old_orig))
 304                old_orig = sha1_old_orig;
 305        if (!get_sha1("HEAD", sha1_orig)) {
 306                orig = sha1_orig;
 307                prepend_reflog_action("updating ORIG_HEAD", msg, sizeof(msg));
 308                update_ref(msg, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
 309        }
 310        else if (old_orig)
 311                delete_ref("ORIG_HEAD", old_orig, 0);
 312        prepend_reflog_action("updating HEAD", msg, sizeof(msg));
 313        update_ref_status = update_ref(msg, "HEAD", sha1, orig, 0, MSG_ON_ERR);
 314
 315        switch (reset_type) {
 316        case HARD:
 317                if (!update_ref_status && !quiet)
 318                        print_new_head_line(commit);
 319                break;
 320        case SOFT: /* Nothing else to do. */
 321                break;
 322        case MIXED: /* Report what has not been updated. */
 323                update_index_refresh(0, NULL,
 324                                quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN);
 325                break;
 326        }
 327
 328        remove_branch_state();
 329
 330        free(reflog_action);
 331
 332        return update_ref_status;
 333}