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