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