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 "lockfile.h"
  12 #include "tag.h"
  13 #include "object.h"
  14 #include "commit.h"
  15 #include "run-command.h"
  16 #include "refs.h"
  17 #include "diff.h"
  18 #include "diffcore.h"
  19 #include "tree.h"
  20 #include "branch.h"
  21 #include "parse-options.h"
  22 #include "unpack-trees.h"
  23 #include "cache-tree.h"
  24 #include "submodule.h"
  25 #include "submodule-config.h"
  26
  27 static int recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
  28
  29 static int option_parse_recurse_submodules(const struct option *opt,
  30                                            const char *arg, int unset)
  31 {
  32         if (unset) {
  33                 recurse_submodules = RECURSE_SUBMODULES_OFF;
  34                 return 0;
  35         }
  36         if (arg)
  37                 recurse_submodules =
  38                         parse_update_recurse_submodules_arg(opt->long_name,
  39                                                             arg);
  40         else
  41                 recurse_submodules = RECURSE_SUBMODULES_ON;
  42
  43         return 0;
  44 }
  45
  46 static const char * const git_reset_usage[] = {
  47         N_("git reset [--mixed | --soft | --hard | --merge | --keep] [-q] [<commit>]"),
  48         N_("git reset [-q] [<tree-ish>] [--] <paths>..."),
  49         N_("git reset --patch [<tree-ish>] [--] [<paths>...]"),
  50         NULL
  51 };
  52
  53 enum reset_type { MIXED, SOFT, HARD, MERGE, KEEP, NONE };
  54 static const char *reset_type_names[] = {
  55         N_("mixed"), N_("soft"), N_("hard"), N_("merge"), N_("keep"), NULL
  56 };
  57
  58 static inline int is_merge(void)
  59 {
  60         return !access(git_path_merge_head(), F_OK);
  61 }
  62
  63 static int reset_index(const struct object_id *oid, int reset_type, int quiet)
  64 {
  65         int nr = 1;
  66         struct tree_desc desc[2];
  67         struct tree *tree;
  68         struct unpack_trees_options opts;
  69
  70         memset(&opts, 0, sizeof(opts));
  71         opts.head_idx = 1;
  72         opts.src_index = &the_index;
  73         opts.dst_index = &the_index;
  74         opts.fn = oneway_merge;
  75         opts.merge = 1;
  76         if (!quiet)
  77                 opts.verbose_update = 1;
  78         switch (reset_type) {
  79         case KEEP:
  80         case MERGE:
  81                 opts.update = 1;
  82                 break;
  83         case HARD:
  84                 opts.update = 1;
  85                 /* fallthrough */
  86         default:
  87                 opts.reset = 1;
  88         }
  89
  90         read_cache_unmerged();
  91
  92         if (reset_type == KEEP) {
  93                 struct object_id head_oid;
  94                 if (get_oid("HEAD", &head_oid))
  95                         return error(_("You do not have a valid HEAD."));
  96                 if (!fill_tree_descriptor(desc, head_oid.hash))
  97                         return error(_("Failed to find tree of HEAD."));
  98                 nr++;
  99                 opts.fn = twoway_merge;
 100         }
 101
 102         if (!fill_tree_descriptor(desc + nr - 1, oid->hash))
 103                 return error(_("Failed to find tree of %s."), oid_to_hex(oid));
 104         if (unpack_trees(nr, desc, &opts))
 105                 return -1;
 106
 107         if (reset_type == MIXED || reset_type == HARD) {
 108                 tree = parse_tree_indirect(oid);
 109                 prime_cache_tree(&the_index, tree);
 110         }
 111
 112         return 0;
 113 }
 114
 115 static void print_new_head_line(struct commit *commit)
 116 {
 117         const char *hex, *body;
 118         const char *msg;
 119
 120         hex = find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV);
 121         printf(_("HEAD is now at %s"), hex);
 122         msg = logmsg_reencode(commit, NULL, get_log_output_encoding());
 123         body = strstr(msg, "\n\n");
 124         if (body) {
 125                 const char *eol;
 126                 size_t len;
 127                 body = skip_blank_lines(body + 2);
 128                 eol = strchr(body, '\n');
 129                 len = eol ? eol - body : strlen(body);
 130                 printf(" %.*s\n", (int) len, body);
 131         }
 132         else
 133                 printf("\n");
 134         unuse_commit_buffer(commit, msg);
 135 }
 136
 137 static void update_index_from_diff(struct diff_queue_struct *q,
 138                 struct diff_options *opt, void *data)
 139 {
 140         int i;
 141         int intent_to_add = *(int *)data;
 142
 143         for (i = 0; i < q->nr; i++) {
 144                 struct diff_filespec *one = q->queue[i]->one;
 145                 int is_missing = !(one->mode && !is_null_oid(&one->oid));
 146                 struct cache_entry *ce;
 147
 148                 if (is_missing && !intent_to_add) {
 149                         remove_file_from_cache(one->path);
 150                         continue;
 151                 }
 152
 153                 ce = make_cache_entry(one->mode, one->oid.hash, one->path,
 154                                       0, 0);
 155                 if (!ce)
 156                         die(_("make_cache_entry failed for path '%s'"),
 157                             one->path);
 158                 if (is_missing) {
 159                         ce->ce_flags |= CE_INTENT_TO_ADD;
 160                         set_object_name_for_intent_to_add_entry(ce);
 161                 }
 162                 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
 163         }
 164 }
 165
 166 static int read_from_tree(const struct pathspec *pathspec,
 167                           struct object_id *tree_oid,
 168                           int intent_to_add)
 169 {
 170         struct diff_options opt;
 171
 172         memset(&opt, 0, sizeof(opt));
 173         copy_pathspec(&opt.pathspec, pathspec);
 174         opt.output_format = DIFF_FORMAT_CALLBACK;
 175         opt.format_callback = update_index_from_diff;
 176         opt.format_callback_data = &intent_to_add;
 177
 178         if (do_diff_cache(tree_oid, &opt))
 179                 return 1;
 180         diffcore_std(&opt);
 181         diff_flush(&opt);
 182         clear_pathspec(&opt.pathspec);
 183
 184         return 0;
 185 }
 186
 187 static void set_reflog_message(struct strbuf *sb, const char *action,
 188                                const char *rev)
 189 {
 190         const char *rla = getenv("GIT_REFLOG_ACTION");
 191
 192         strbuf_reset(sb);
 193         if (rla)
 194                 strbuf_addf(sb, "%s: %s", rla, action);
 195         else if (rev)
 196                 strbuf_addf(sb, "reset: moving to %s", rev);
 197         else
 198                 strbuf_addf(sb, "reset: %s", action);
 199 }
 200
 201 static void die_if_unmerged_cache(int reset_type)
 202 {
 203         if (is_merge() || unmerged_cache())
 204                 die(_("Cannot do a %s reset in the middle of a merge."),
 205                     _(reset_type_names[reset_type]));
 206
 207 }
 208
 209 static void parse_args(struct pathspec *pathspec,
 210                        const char **argv, const char *prefix,
 211                        int patch_mode,
 212                        const char **rev_ret)
 213 {
 214         const char *rev = "HEAD";
 215         struct object_id unused;
 216         /*
 217          * Possible arguments are:
 218          *
 219          * git reset [-opts] [<rev>]
 220          * git reset [-opts] <tree> [<paths>...]
 221          * git reset [-opts] <tree> -- [<paths>...]
 222          * git reset [-opts] -- [<paths>...]
 223          * git reset [-opts] <paths>...
 224          *
 225          * At this point, argv points immediately after [-opts].
 226          */
 227
 228         if (argv[0]) {
 229                 if (!strcmp(argv[0], "--")) {
 230                         argv++; /* reset to HEAD, possibly with paths */
 231                 } else if (argv[1] && !strcmp(argv[1], "--")) {
 232                         rev = argv[0];
 233                         argv += 2;
 234                 }
 235                 /*
 236                  * Otherwise, argv[0] could be either <rev> or <paths> and
 237                  * has to be unambiguous. If there is a single argument, it
 238                  * can not be a tree
 239                  */
 240                 else if ((!argv[1] && !get_sha1_committish(argv[0], unused.hash)) ||
 241                          (argv[1] && !get_sha1_treeish(argv[0], unused.hash))) {
 242                         /*
 243                          * Ok, argv[0] looks like a commit/tree; it should not
 244                          * be a filename.
 245                          */
 246                         verify_non_filename(prefix, argv[0]);
 247                         rev = *argv++;
 248                 } else {
 249                         /* Otherwise we treat this as a filename */
 250                         verify_filename(prefix, argv[0], 1);
 251                 }
 252         }
 253         *rev_ret = rev;
 254
 255         if (read_cache() < 0)
 256                 die(_("index file corrupt"));
 257
 258         parse_pathspec(pathspec, 0,
 259                        PATHSPEC_PREFER_FULL |
 260                        (patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0),
 261                        prefix, argv);
 262 }
 263
 264 static int reset_refs(const char *rev, const struct object_id *oid)
 265 {
 266         int update_ref_status;
 267         struct strbuf msg = STRBUF_INIT;
 268         struct object_id *orig = NULL, oid_orig,
 269                 *old_orig = NULL, oid_old_orig;
 270
 271         if (!get_oid("ORIG_HEAD", &oid_old_orig))
 272                 old_orig = &oid_old_orig;
 273         if (!get_oid("HEAD", &oid_orig)) {
 274                 orig = &oid_orig;
 275                 set_reflog_message(&msg, "updating ORIG_HEAD", NULL);
 276                 update_ref_oid(msg.buf, "ORIG_HEAD", orig, old_orig, 0,
 277                            UPDATE_REFS_MSG_ON_ERR);
 278         } else if (old_orig)
 279                 delete_ref(NULL, "ORIG_HEAD", old_orig->hash, 0);
 280         set_reflog_message(&msg, "updating HEAD", rev);
 281         update_ref_status = update_ref_oid(msg.buf, "HEAD", oid, orig, 0,
 282                                        UPDATE_REFS_MSG_ON_ERR);
 283         strbuf_release(&msg);
 284         return update_ref_status;
 285 }
 286
 287 int cmd_reset(int argc, const char **argv, const char *prefix)
 288 {
 289         int reset_type = NONE, update_ref_status = 0, quiet = 0;
 290         int patch_mode = 0, unborn;
 291         const char *rev;
 292         struct object_id oid;
 293         struct pathspec pathspec;
 294         int intent_to_add = 0;
 295         const struct option options[] = {
 296                 OPT__QUIET(&quiet, N_("be quiet, only report errors")),
 297                 OPT_SET_INT(0, "mixed", &reset_type,
 298                                                 N_("reset HEAD and index"), MIXED),
 299                 OPT_SET_INT(0, "soft", &reset_type, N_("reset only HEAD"), SOFT),
 300                 OPT_SET_INT(0, "hard", &reset_type,
 301                                 N_("reset HEAD, index and working tree"), HARD),
 302                 OPT_SET_INT(0, "merge", &reset_type,
 303                                 N_("reset HEAD, index and working tree"), MERGE),
 304                 OPT_SET_INT(0, "keep", &reset_type,
 305                                 N_("reset HEAD but keep local changes"), KEEP),
 306                 { OPTION_CALLBACK, 0, "recurse-submodules", &recurse_submodules,
 307                             "reset", "control recursive updating of submodules",
 308                             PARSE_OPT_OPTARG, option_parse_recurse_submodules },
 309                 OPT_BOOL('p', "patch", &patch_mode, N_("select hunks interactively")),
 310                 OPT_BOOL('N', "intent-to-add", &intent_to_add,
 311                                 N_("record only the fact that removed paths will be added later")),
 312                 OPT_END()
 313         };
 314
 315         git_config(git_default_config, NULL);
 316
 317         argc = parse_options(argc, argv, prefix, options, git_reset_usage,
 318                                                 PARSE_OPT_KEEP_DASHDASH);
 319         parse_args(&pathspec, argv, prefix, patch_mode, &rev);
 320
 321         if (recurse_submodules != RECURSE_SUBMODULES_DEFAULT) {
 322                 gitmodules_config();
 323                 git_config(submodule_config, NULL);
 324                 set_config_update_recurse_submodules(RECURSE_SUBMODULES_ON);
 325         }
 326
 327         unborn = !strcmp(rev, "HEAD") && get_sha1("HEAD", oid.hash);
 328         if (unborn) {
 329                 /* reset on unborn branch: treat as reset to empty tree */
 330                 hashcpy(oid.hash, EMPTY_TREE_SHA1_BIN);
 331         } else if (!pathspec.nr) {
 332                 struct commit *commit;
 333                 if (get_sha1_committish(rev, oid.hash))
 334                         die(_("Failed to resolve '%s' as a valid revision."), rev);
 335                 commit = lookup_commit_reference(&oid);
 336                 if (!commit)
 337                         die(_("Could not parse object '%s'."), rev);
 338                 oidcpy(&oid, &commit->object.oid);
 339         } else {
 340                 struct tree *tree;
 341                 if (get_sha1_treeish(rev, oid.hash))
 342                         die(_("Failed to resolve '%s' as a valid tree."), rev);
 343                 tree = parse_tree_indirect(&oid);
 344                 if (!tree)
 345                         die(_("Could not parse object '%s'."), rev);
 346                 oidcpy(&oid, &tree->object.oid);
 347         }
 348
 349         if (patch_mode) {
 350                 if (reset_type != NONE)
 351                         die(_("--patch is incompatible with --{hard,mixed,soft}"));
 352                 return run_add_interactive(rev, "--patch=reset", &pathspec);
 353         }
 354
 355         /* git reset tree [--] paths... can be used to
 356          * load chosen paths from the tree into the index without
 357          * affecting the working tree nor HEAD. */
 358         if (pathspec.nr) {
 359                 if (reset_type == MIXED)
 360                         warning(_("--mixed with paths is deprecated; use 'git reset -- <paths>' instead."));
 361                 else if (reset_type != NONE)
 362                         die(_("Cannot do %s reset with paths."),
 363                                         _(reset_type_names[reset_type]));
 364         }
 365         if (reset_type == NONE)
 366                 reset_type = MIXED; /* by default */
 367
 368         if (reset_type != SOFT && (reset_type != MIXED || get_git_work_tree()))
 369                 setup_work_tree();
 370
 371         if (reset_type == MIXED && is_bare_repository())
 372                 die(_("%s reset is not allowed in a bare repository"),
 373                     _(reset_type_names[reset_type]));
 374
 375         if (intent_to_add && reset_type != MIXED)
 376                 die(_("-N can only be used with --mixed"));
 377
 378         /* Soft reset does not touch the index file nor the working tree
 379          * at all, but requires them in a good order.  Other resets reset
 380          * the index file to the tree object we are switching to. */
 381         if (reset_type == SOFT || reset_type == KEEP)
 382                 die_if_unmerged_cache(reset_type);
 383
 384         if (reset_type != SOFT) {
 385                 struct lock_file *lock = xcalloc(1, sizeof(*lock));
 386                 hold_locked_index(lock, LOCK_DIE_ON_ERROR);
 387                 if (reset_type == MIXED) {
 388                         int flags = quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN;
 389                         if (read_from_tree(&pathspec, &oid, intent_to_add))
 390                                 return 1;
 391                         if (get_git_work_tree())
 392                                 refresh_index(&the_index, flags, NULL, NULL,
 393                                               _("Unstaged changes after reset:"));
 394                 } else {
 395                         int err = reset_index(&oid, reset_type, quiet);
 396                         if (reset_type == KEEP && !err)
 397                                 err = reset_index(&oid, MIXED, quiet);
 398                         if (err)
 399                                 die(_("Could not reset index file to revision '%s'."), rev);
 400                 }
 401
 402                 if (write_locked_index(&the_index, lock, COMMIT_LOCK))
 403                         die(_("Could not write new index file."));
 404         }
 405
 406         if (!pathspec.nr && !unborn) {
 407                 /* Any resets without paths update HEAD to the head being
 408                  * switched to, saving the previous head in ORIG_HEAD before. */
 409                 update_ref_status = reset_refs(rev, &oid);
 410
 411                 if (reset_type == HARD && !update_ref_status && !quiet)
 412                         print_new_head_line(lookup_commit_reference(&oid));
 413         }
 414         if (!pathspec.nr)
 415                 remove_branch_state();
 416
 417         return update_ref_status;
 418 }