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 "pretty.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(the_repository), 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         struct strbuf buf = STRBUF_INIT;
 110
 111         printf(_("HEAD is now at %s"),
 112                 find_unique_abbrev(&commit->object.oid, DEFAULT_ABBREV));
 113
 114         pp_commit_easy(CMIT_FMT_ONELINE, commit, &buf);
 115         if (buf.len > 0)
 116                 printf(" %s", buf.buf);
 117         putchar('\n');
 118         strbuf_release(&buf);
 119 }
 120
 121 static void update_index_from_diff(struct diff_queue_struct *q,
 122                 struct diff_options *opt, void *data)
 123 {
 124         int i;
 125         int intent_to_add = *(int *)data;
 126
 127         for (i = 0; i < q->nr; i++) {
 128                 struct diff_filespec *one = q->queue[i]->one;
 129                 int is_missing = !(one->mode && !is_null_oid(&one->oid));
 130                 struct cache_entry *ce;
 131
 132                 if (is_missing && !intent_to_add) {
 133                         remove_file_from_cache(one->path);
 134                         continue;
 135                 }
 136
 137                 ce = make_cache_entry(one->mode, one->oid.hash, one->path,
 138                                       0, 0);
 139                 if (!ce)
 140                         die(_("make_cache_entry failed for path '%s'"),
 141                             one->path);
 142                 if (is_missing) {
 143                         ce->ce_flags |= CE_INTENT_TO_ADD;
 144                         set_object_name_for_intent_to_add_entry(ce);
 145                 }
 146                 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
 147         }
 148 }
 149
 150 static int read_from_tree(const struct pathspec *pathspec,
 151                           struct object_id *tree_oid,
 152                           int intent_to_add)
 153 {
 154         struct diff_options opt;
 155
 156         memset(&opt, 0, sizeof(opt));
 157         copy_pathspec(&opt.pathspec, pathspec);
 158         opt.output_format = DIFF_FORMAT_CALLBACK;
 159         opt.format_callback = update_index_from_diff;
 160         opt.format_callback_data = &intent_to_add;
 161         opt.flags.override_submodule_config = 1;
 162
 163         if (do_diff_cache(tree_oid, &opt))
 164                 return 1;
 165         diffcore_std(&opt);
 166         diff_flush(&opt);
 167         clear_pathspec(&opt.pathspec);
 168
 169         return 0;
 170 }
 171
 172 static void set_reflog_message(struct strbuf *sb, const char *action,
 173                                const char *rev)
 174 {
 175         const char *rla = getenv("GIT_REFLOG_ACTION");
 176
 177         strbuf_reset(sb);
 178         if (rla)
 179                 strbuf_addf(sb, "%s: %s", rla, action);
 180         else if (rev)
 181                 strbuf_addf(sb, "reset: moving to %s", rev);
 182         else
 183                 strbuf_addf(sb, "reset: %s", action);
 184 }
 185
 186 static void die_if_unmerged_cache(int reset_type)
 187 {
 188         if (is_merge() || unmerged_cache())
 189                 die(_("Cannot do a %s reset in the middle of a merge."),
 190                     _(reset_type_names[reset_type]));
 191
 192 }
 193
 194 static void parse_args(struct pathspec *pathspec,
 195                        const char **argv, const char *prefix,
 196                        int patch_mode,
 197                        const char **rev_ret)
 198 {
 199         const char *rev = "HEAD";
 200         struct object_id unused;
 201         /*
 202          * Possible arguments are:
 203          *
 204          * git reset [-opts] [<rev>]
 205          * git reset [-opts] <tree> [<paths>...]
 206          * git reset [-opts] <tree> -- [<paths>...]
 207          * git reset [-opts] -- [<paths>...]
 208          * git reset [-opts] <paths>...
 209          *
 210          * At this point, argv points immediately after [-opts].
 211          */
 212
 213         if (argv[0]) {
 214                 if (!strcmp(argv[0], "--")) {
 215                         argv++; /* reset to HEAD, possibly with paths */
 216                 } else if (argv[1] && !strcmp(argv[1], "--")) {
 217                         rev = argv[0];
 218                         argv += 2;
 219                 }
 220                 /*
 221                  * Otherwise, argv[0] could be either <rev> or <paths> and
 222                  * has to be unambiguous. If there is a single argument, it
 223                  * can not be a tree
 224                  */
 225                 else if ((!argv[1] && !get_oid_committish(argv[0], &unused)) ||
 226                          (argv[1] && !get_oid_treeish(argv[0], &unused))) {
 227                         /*
 228                          * Ok, argv[0] looks like a commit/tree; it should not
 229                          * be a filename.
 230                          */
 231                         verify_non_filename(prefix, argv[0]);
 232                         rev = *argv++;
 233                 } else {
 234                         /* Otherwise we treat this as a filename */
 235                         verify_filename(prefix, argv[0], 1);
 236                 }
 237         }
 238         *rev_ret = rev;
 239
 240         if (read_cache() < 0)
 241                 die(_("index file corrupt"));
 242
 243         parse_pathspec(pathspec, 0,
 244                        PATHSPEC_PREFER_FULL |
 245                        (patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0),
 246                        prefix, argv);
 247 }
 248
 249 static int reset_refs(const char *rev, const struct object_id *oid)
 250 {
 251         int update_ref_status;
 252         struct strbuf msg = STRBUF_INIT;
 253         struct object_id *orig = NULL, oid_orig,
 254                 *old_orig = NULL, oid_old_orig;
 255
 256         if (!get_oid("ORIG_HEAD", &oid_old_orig))
 257                 old_orig = &oid_old_orig;
 258         if (!get_oid("HEAD", &oid_orig)) {
 259                 orig = &oid_orig;
 260                 set_reflog_message(&msg, "updating ORIG_HEAD", NULL);
 261                 update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0,
 262                            UPDATE_REFS_MSG_ON_ERR);
 263         } else if (old_orig)
 264                 delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 265         set_reflog_message(&msg, "updating HEAD", rev);
 266         update_ref_status = update_ref(msg.buf, "HEAD", oid, orig, 0,
 267                                        UPDATE_REFS_MSG_ON_ERR);
 268         strbuf_release(&msg);
 269         return update_ref_status;
 270 }
 271
 272 static int git_reset_config(const char *var, const char *value, void *cb)
 273 {
 274         if (!strcmp(var, "submodule.recurse"))
 275                 return git_default_submodule_config(var, value, cb);
 276
 277         return git_default_config(var, value, cb);
 278 }
 279
 280 int cmd_reset(int argc, const char **argv, const char *prefix)
 281 {
 282         int reset_type = NONE, update_ref_status = 0, quiet = 0;
 283         int patch_mode = 0, unborn;
 284         const char *rev;
 285         struct object_id oid;
 286         struct pathspec pathspec;
 287         int intent_to_add = 0;
 288         const struct option options[] = {
 289                 OPT__QUIET(&quiet, N_("be quiet, only report errors")),
 290                 OPT_SET_INT(0, "mixed", &reset_type,
 291                                                 N_("reset HEAD and index"), MIXED),
 292                 OPT_SET_INT(0, "soft", &reset_type, N_("reset only HEAD"), SOFT),
 293                 OPT_SET_INT(0, "hard", &reset_type,
 294                                 N_("reset HEAD, index and working tree"), HARD),
 295                 OPT_SET_INT(0, "merge", &reset_type,
 296                                 N_("reset HEAD, index and working tree"), MERGE),
 297                 OPT_SET_INT(0, "keep", &reset_type,
 298                                 N_("reset HEAD but keep local changes"), KEEP),
 299                 { OPTION_CALLBACK, 0, "recurse-submodules", NULL,
 300                             "reset", "control recursive updating of submodules",
 301                             PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater },
 302                 OPT_BOOL('p', "patch", &patch_mode, N_("select hunks interactively")),
 303                 OPT_BOOL('N', "intent-to-add", &intent_to_add,
 304                                 N_("record only the fact that removed paths will be added later")),
 305                 OPT_END()
 306         };
 307
 308         git_config(git_reset_config, NULL);
 309
 310         argc = parse_options(argc, argv, prefix, options, git_reset_usage,
 311                                                 PARSE_OPT_KEEP_DASHDASH);
 312         parse_args(&pathspec, argv, prefix, patch_mode, &rev);
 313
 314         unborn = !strcmp(rev, "HEAD") && get_oid("HEAD", &oid);
 315         if (unborn) {
 316                 /* reset on unborn branch: treat as reset to empty tree */
 317                 oidcpy(&oid, the_hash_algo->empty_tree);
 318         } else if (!pathspec.nr) {
 319                 struct commit *commit;
 320                 if (get_oid_committish(rev, &oid))
 321                         die(_("Failed to resolve '%s' as a valid revision."), rev);
 322                 commit = lookup_commit_reference(&oid);
 323                 if (!commit)
 324                         die(_("Could not parse object '%s'."), rev);
 325                 oidcpy(&oid, &commit->object.oid);
 326         } else {
 327                 struct tree *tree;
 328                 if (get_oid_treeish(rev, &oid))
 329                         die(_("Failed to resolve '%s' as a valid tree."), rev);
 330                 tree = parse_tree_indirect(&oid);
 331                 if (!tree)
 332                         die(_("Could not parse object '%s'."), rev);
 333                 oidcpy(&oid, &tree->object.oid);
 334         }
 335
 336         if (patch_mode) {
 337                 if (reset_type != NONE)
 338                         die(_("--patch is incompatible with --{hard,mixed,soft}"));
 339                 return run_add_interactive(rev, "--patch=reset", &pathspec);
 340         }
 341
 342         /* git reset tree [--] paths... can be used to
 343          * load chosen paths from the tree into the index without
 344          * affecting the working tree nor HEAD. */
 345         if (pathspec.nr) {
 346                 if (reset_type == MIXED)
 347                         warning(_("--mixed with paths is deprecated; use 'git reset -- <paths>' instead."));
 348                 else if (reset_type != NONE)
 349                         die(_("Cannot do %s reset with paths."),
 350                                         _(reset_type_names[reset_type]));
 351         }
 352         if (reset_type == NONE)
 353                 reset_type = MIXED; /* by default */
 354
 355         if (reset_type != SOFT && (reset_type != MIXED || get_git_work_tree()))
 356                 setup_work_tree();
 357
 358         if (reset_type == MIXED && is_bare_repository())
 359                 die(_("%s reset is not allowed in a bare repository"),
 360                     _(reset_type_names[reset_type]));
 361
 362         if (intent_to_add && reset_type != MIXED)
 363                 die(_("-N can only be used with --mixed"));
 364
 365         /* Soft reset does not touch the index file nor the working tree
 366          * at all, but requires them in a good order.  Other resets reset
 367          * the index file to the tree object we are switching to. */
 368         if (reset_type == SOFT || reset_type == KEEP)
 369                 die_if_unmerged_cache(reset_type);
 370
 371         if (reset_type != SOFT) {
 372                 struct lock_file lock = LOCK_INIT;
 373                 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
 374                 if (reset_type == MIXED) {
 375                         int flags = quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN;
 376                         if (read_from_tree(&pathspec, &oid, intent_to_add))
 377                                 return 1;
 378                         if (get_git_work_tree())
 379                                 refresh_index(&the_index, flags, NULL, NULL,
 380                                               _("Unstaged changes after reset:"));
 381                 } else {
 382                         int err = reset_index(&oid, reset_type, quiet);
 383                         if (reset_type == KEEP && !err)
 384                                 err = reset_index(&oid, MIXED, quiet);
 385                         if (err)
 386                                 die(_("Could not reset index file to revision '%s'."), rev);
 387                 }
 388
 389                 if (write_locked_index(&the_index, &lock, COMMIT_LOCK))
 390                         die(_("Could not write new index file."));
 391         }
 392
 393         if (!pathspec.nr && !unborn) {
 394                 /* Any resets without paths update HEAD to the head being
 395                  * switched to, saving the previous head in ORIG_HEAD before. */
 396                 update_ref_status = reset_refs(rev, &oid);
 397
 398                 if (reset_type == HARD && !update_ref_status && !quiet)
 399                         print_new_head_line(lookup_commit_reference(&oid));
 400         }
 401         if (!pathspec.nr)
 402                 remove_branch_state();
 403
 404         return update_ref_status;
 405 }