builtin/reset.c

   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 "config.h"
  12 #include "lockfile.h"
  13 #include "tag.h"
  14 #include "object.h"
  15 #include "commit.h"
  16 #include "run-command.h"
  17 #include "refs.h"
  18 #include "diff.h"
  19 #include "diffcore.h"
  20 #include "tree.h"
  21 #include "branch.h"
  22 #include "parse-options.h"
  23 #include "unpack-trees.h"
  24 #include "cache-tree.h"
  25 #include "submodule.h"
  26 #include "submodule-config.h"
  27
  28 static const char * const git_reset_usage[] = {
  29         N_("git reset [--mixed | --soft | --hard | --merge | --keep] [-q] [<commit>]"),
  30         N_("git reset [-q] [<tree-ish>] [--] <paths>..."),
  31         N_("git reset --patch [<tree-ish>] [--] [<paths>...]"),
  32         NULL
  33 };
  34
  35 enum reset_type { MIXED, SOFT, HARD, MERGE, KEEP, NONE };
  36 static const char *reset_type_names[] = {
  37         N_("mixed"), N_("soft"), N_("hard"), N_("merge"), N_("keep"), NULL
  38 };
  39
  40 static inline int is_merge(void)
  41 {
  42         return !access(git_path_merge_head(), F_OK);
  43 }
  44
  45 static int reset_index(const struct object_id *oid, int reset_type, int quiet)
  46 {
  47         int i, nr = 0;
  48         struct tree_desc desc[2];
  49         struct tree *tree;
  50         struct unpack_trees_options opts;
  51         int ret = -1;
  52
  53         memset(&opts, 0, sizeof(opts));
  54         opts.head_idx = 1;
  55         opts.src_index = &the_index;
  56         opts.dst_index = &the_index;
  57         opts.fn = oneway_merge;
  58         opts.merge = 1;
  59         if (!quiet)
  60                 opts.verbose_update = 1;
  61         switch (reset_type) {
  62         case KEEP:
  63         case MERGE:
  64                 opts.update = 1;
  65                 break;
  66         case HARD:
  67                 opts.update = 1;
  68                 /* fallthrough */
  69         default:
  70                 opts.reset = 1;
  71         }
  72
  73         read_cache_unmerged();
  74
  75         if (reset_type == KEEP) {
  76                 struct object_id head_oid;
  77                 if (get_oid("HEAD", &head_oid))
  78                         return error(_("You do not have a valid HEAD."));
  79                 if (!fill_tree_descriptor(desc + nr, &head_oid))
  80                         return error(_("Failed to find tree of HEAD."));
  81                 nr++;
  82                 opts.fn = twoway_merge;
  83         }
  84
  85         if (!fill_tree_descriptor(desc + nr, oid)) {
  86                 error(_("Failed to find tree of %s."), oid_to_hex(oid));
  87                 goto out;
  88         }
  89         nr++;
  90
  91         if (unpack_trees(nr, desc, &opts))
  92                 goto out;
  93
  94         if (reset_type == MIXED || reset_type == HARD) {
  95                 tree = parse_tree_indirect(oid);
  96                 prime_cache_tree(&the_index, tree);
  97         }
  98
  99         ret = 0;
 100
 101 out:
 102         for (i = 0; i < nr; i++)
 103                 free((void *)desc[i].buffer);
 104         return ret;
 105 }
 106
 107 static void print_new_head_line(struct commit *commit)
 108 {
 109         const char *hex, *body;
 110         const char *msg;
 111
 112         hex = find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV);
 113         printf(_("HEAD is now at %s"), hex);
 114         msg = logmsg_reencode(commit, NULL, get_log_output_encoding());
 115         body = strstr(msg, "\n\n");
 116         if (body) {
 117                 const char *eol;
 118                 size_t len;
 119                 body = skip_blank_lines(body + 2);
 120                 eol = strchr(body, '\n');
 121                 len = eol ? eol - body : strlen(body);
 122                 printf(" %.*s\n", (int) len, body);
 123         }
 124         else
 125                 printf("\n");
 126         unuse_commit_buffer(commit, msg);
 127 }
 128
 129 static void update_index_from_diff(struct diff_queue_struct *q,
 130                 struct diff_options *opt, void *data)
 131 {
 132         int i;
 133         int intent_to_add = *(int *)data;
 134
 135         for (i = 0; i < q->nr; i++) {
 136                 struct diff_filespec *one = q->queue[i]->one;
 137                 int is_missing = !(one->mode && !is_null_oid(&one->oid));
 138                 struct cache_entry *ce;
 139
 140                 if (is_missing && !intent_to_add) {
 141                         remove_file_from_cache(one->path);
 142                         continue;
 143                 }
 144
 145                 ce = make_cache_entry(one->mode, one->oid.hash, one->path,
 146                                       0, 0);
 147                 if (!ce)
 148                         die(_("make_cache_entry failed for path '%s'"),
 149                             one->path);
 150                 if (is_missing) {
 151                         ce->ce_flags |= CE_INTENT_TO_ADD;
 152                         set_object_name_for_intent_to_add_entry(ce);
 153                 }
 154                 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
 155         }
 156 }
 157
 158 static int read_from_tree(const struct pathspec *pathspec,
 159                           struct object_id *tree_oid,
 160                           int intent_to_add)
 161 {
 162         struct diff_options opt;
 163
 164         memset(&opt, 0, sizeof(opt));
 165         copy_pathspec(&opt.pathspec, pathspec);
 166         opt.output_format = DIFF_FORMAT_CALLBACK;
 167         opt.format_callback = update_index_from_diff;
 168         opt.format_callback_data = &intent_to_add;
 169         opt.flags |= DIFF_OPT_OVERRIDE_SUBMODULE_CONFIG;
 170
 171         if (do_diff_cache(tree_oid, &opt))
 172                 return 1;
 173         diffcore_std(&opt);
 174         diff_flush(&opt);
 175         clear_pathspec(&opt.pathspec);
 176
 177         return 0;
 178 }
 179
 180 static void set_reflog_message(struct strbuf *sb, const char *action,
 181                                const char *rev)
 182 {
 183         const char *rla = getenv("GIT_REFLOG_ACTION");
 184
 185         strbuf_reset(sb);
 186         if (rla)
 187                 strbuf_addf(sb, "%s: %s", rla, action);
 188         else if (rev)
 189                 strbuf_addf(sb, "reset: moving to %s", rev);
 190         else
 191                 strbuf_addf(sb, "reset: %s", action);
 192 }
 193
 194 static void die_if_unmerged_cache(int reset_type)
 195 {
 196         if (is_merge() || unmerged_cache())
 197                 die(_("Cannot do a %s reset in the middle of a merge."),
 198                     _(reset_type_names[reset_type]));
 199
 200 }
 201
 202 static void parse_args(struct pathspec *pathspec,
 203                        const char **argv, const char *prefix,
 204                        int patch_mode,
 205                        const char **rev_ret)
 206 {
 207         const char *rev = "HEAD";
 208         struct object_id unused;
 209         /*
 210          * Possible arguments are:
 211          *
 212          * git reset [-opts] [<rev>]
 213          * git reset [-opts] <tree> [<paths>...]
 214          * git reset [-opts] <tree> -- [<paths>...]
 215          * git reset [-opts] -- [<paths>...]
 216          * git reset [-opts] <paths>...
 217          *
 218          * At this point, argv points immediately after [-opts].
 219          */
 220
 221         if (argv[0]) {
 222                 if (!strcmp(argv[0], "--")) {
 223                         argv++; /* reset to HEAD, possibly with paths */
 224                 } else if (argv[1] && !strcmp(argv[1], "--")) {
 225                         rev = argv[0];
 226                         argv += 2;
 227                 }
 228                 /*
 229                  * Otherwise, argv[0] could be either <rev> or <paths> and
 230                  * has to be unambiguous. If there is a single argument, it
 231                  * can not be a tree
 232                  */
 233                 else if ((!argv[1] && !get_oid_committish(argv[0], &unused)) ||
 234                          (argv[1] && !get_oid_treeish(argv[0], &unused))) {
 235                         /*
 236                          * Ok, argv[0] looks like a commit/tree; it should not
 237                          * be a filename.
 238                          */
 239                         verify_non_filename(prefix, argv[0]);
 240                         rev = *argv++;
 241                 } else {
 242                         /* Otherwise we treat this as a filename */
 243                         verify_filename(prefix, argv[0], 1);
 244                 }
 245         }
 246         *rev_ret = rev;
 247
 248         if (read_cache() < 0)
 249                 die(_("index file corrupt"));
 250
 251         parse_pathspec(pathspec, 0,
 252                        PATHSPEC_PREFER_FULL |
 253                        (patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0),
 254                        prefix, argv);
 255 }
 256
 257 static int reset_refs(const char *rev, const struct object_id *oid)
 258 {
 259         int update_ref_status;
 260         struct strbuf msg = STRBUF_INIT;
 261         struct object_id *orig = NULL, oid_orig,
 262                 *old_orig = NULL, oid_old_orig;
 263
 264         if (!get_oid("ORIG_HEAD", &oid_old_orig))
 265                 old_orig = &oid_old_orig;
 266         if (!get_oid("HEAD", &oid_orig)) {
 267                 orig = &oid_orig;
 268                 set_reflog_message(&msg, "updating ORIG_HEAD", NULL);
 269                 update_ref_oid(msg.buf, "ORIG_HEAD", orig, old_orig, 0,
 270                            UPDATE_REFS_MSG_ON_ERR);
 271         } else if (old_orig)
 272                 delete_ref(NULL, "ORIG_HEAD", old_orig->hash, 0);
 273         set_reflog_message(&msg, "updating HEAD", rev);
 274         update_ref_status = update_ref_oid(msg.buf, "HEAD", oid, orig, 0,
 275                                        UPDATE_REFS_MSG_ON_ERR);
 276         strbuf_release(&msg);
 277         return update_ref_status;
 278 }
 279
 280 static int git_reset_config(const char *var, const char *value, void *cb)
 281 {
 282         if (!strcmp(var, "submodule.recurse"))
 283                 return git_default_submodule_config(var, value, cb);
 284
 285         return git_default_config(var, value, cb);
 286 }
 287
 288 int cmd_reset(int argc, const char **argv, const char *prefix)
 289 {
 290         int reset_type = NONE, update_ref_status = 0, quiet = 0;
 291         int patch_mode = 0, unborn;
 292         const char *rev;
 293         struct object_id oid;
 294         struct pathspec pathspec;
 295         int intent_to_add = 0;
 296         const struct option options[] = {
 297                 OPT__QUIET(&quiet, N_("be quiet, only report errors")),
 298                 OPT_SET_INT(0, "mixed", &reset_type,
 299                                                 N_("reset HEAD and index"), MIXED),
 300                 OPT_SET_INT(0, "soft", &reset_type, N_("reset only HEAD"), SOFT),
 301                 OPT_SET_INT(0, "hard", &reset_type,
 302                                 N_("reset HEAD, index and working tree"), HARD),
 303                 OPT_SET_INT(0, "merge", &reset_type,
 304                                 N_("reset HEAD, index and working tree"), MERGE),
 305                 OPT_SET_INT(0, "keep", &reset_type,
 306                                 N_("reset HEAD but keep local changes"), KEEP),
 307                 { OPTION_CALLBACK, 0, "recurse-submodules", NULL,
 308                             "reset", "control recursive updating of submodules",
 309                             PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater },
 310                 OPT_BOOL('p', "patch", &patch_mode, N_("select hunks interactively")),
 311                 OPT_BOOL('N', "intent-to-add", &intent_to_add,
 312                                 N_("record only the fact that removed paths will be added later")),
 313                 OPT_END()
 314         };
 315
 316         git_config(git_reset_config, NULL);
 317
 318         argc = parse_options(argc, argv, prefix, options, git_reset_usage,
 319                                                 PARSE_OPT_KEEP_DASHDASH);
 320         parse_args(&pathspec, argv, prefix, patch_mode, &rev);
 321
 322         unborn = !strcmp(rev, "HEAD") && get_oid("HEAD", &oid);
 323         if (unborn) {
 324                 /* reset on unborn branch: treat as reset to empty tree */
 325                 hashcpy(oid.hash, EMPTY_TREE_SHA1_BIN);
 326         } else if (!pathspec.nr) {
 327                 struct commit *commit;
 328                 if (get_oid_committish(rev, &oid))
 329                         die(_("Failed to resolve '%s' as a valid revision."), rev);
 330                 commit = lookup_commit_reference(&oid);
 331                 if (!commit)
 332                         die(_("Could not parse object '%s'."), rev);
 333                 oidcpy(&oid, &commit->object.oid);
 334         } else {
 335                 struct tree *tree;
 336                 if (get_oid_treeish(rev, &oid))
 337                         die(_("Failed to resolve '%s' as a valid tree."), rev);
 338                 tree = parse_tree_indirect(&oid);
 339                 if (!tree)
 340                         die(_("Could not parse object '%s'."), rev);
 341                 oidcpy(&oid, &tree->object.oid);
 342         }
 343
 344         if (patch_mode) {
 345                 if (reset_type != NONE)
 346                         die(_("--patch is incompatible with --{hard,mixed,soft}"));
 347                 return run_add_interactive(rev, "--patch=reset", &pathspec);
 348         }
 349
 350         /* git reset tree [--] paths... can be used to
 351          * load chosen paths from the tree into the index without
 352          * affecting the working tree nor HEAD. */
 353         if (pathspec.nr) {
 354                 if (reset_type == MIXED)
 355                         warning(_("--mixed with paths is deprecated; use 'git reset -- <paths>' instead."));
 356                 else if (reset_type != NONE)
 357                         die(_("Cannot do %s reset with paths."),
 358                                         _(reset_type_names[reset_type]));
 359         }
 360         if (reset_type == NONE)
 361                 reset_type = MIXED; /* by default */
 362
 363         if (reset_type != SOFT && (reset_type != MIXED || get_git_work_tree()))
 364                 setup_work_tree();
 365
 366         if (reset_type == MIXED && is_bare_repository())
 367                 die(_("%s reset is not allowed in a bare repository"),
 368                     _(reset_type_names[reset_type]));
 369
 370         if (intent_to_add && reset_type != MIXED)
 371                 die(_("-N can only be used with --mixed"));
 372
 373         /* Soft reset does not touch the index file nor the working tree
 374          * at all, but requires them in a good order.  Other resets reset
 375          * the index file to the tree object we are switching to. */
 376         if (reset_type == SOFT || reset_type == KEEP)
 377                 die_if_unmerged_cache(reset_type);
 378
 379         if (reset_type != SOFT) {
 380                 struct lock_file lock = LOCK_INIT;
 381                 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
 382                 if (reset_type == MIXED) {
 383                         int flags = quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN;
 384                         if (read_from_tree(&pathspec, &oid, intent_to_add))
 385                                 return 1;
 386                         if (get_git_work_tree())
 387                                 refresh_index(&the_index, flags, NULL, NULL,
 388                                               _("Unstaged changes after reset:"));
 389                 } else {
 390                         int err = reset_index(&oid, reset_type, quiet);
 391                         if (reset_type == KEEP && !err)
 392                                 err = reset_index(&oid, MIXED, quiet);
 393                         if (err)
 394                                 die(_("Could not reset index file to revision '%s'."), rev);
 395                 }
 396
 397                 if (write_locked_index(&the_index, &lock, COMMIT_LOCK))
 398                         die(_("Could not write new index file."));
 399         }
 400
 401         if (!pathspec.nr && !unborn) {
 402                 /* Any resets without paths update HEAD to the head being
 403                  * switched to, saving the previous head in ORIG_HEAD before. */
 404                 update_ref_status = reset_refs(rev, &oid);
 405
 406                 if (reset_type == HARD && !update_ref_status && !quiet)
 407                         print_new_head_line(lookup_commit_reference(&oid));
 408         }
 409         if (!pathspec.nr)
 410                 remove_branch_state();
 411
 412         return update_ref_status;
 413 }