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