builtin/read-tree.c

   1 /*
   2  * GIT - The information manager from hell
   3  *
   4  * Copyright (C) Linus Torvalds, 2005
   5  */
   6
   7 #define USE_THE_INDEX_VARIABLE
   8 #include "cache.h"
   9 #include "config.h"
  10 #include "lockfile.h"
  11 #include "object.h"
  12 #include "tree.h"
  13 #include "tree-walk.h"
  14 #include "cache-tree.h"
  15 #include "unpack-trees.h"
  16 #include "dir.h"
  17 #include "builtin.h"
  18 #include "parse-options.h"
  19 #include "resolve-undo.h"
  20 #include "submodule.h"
  21 #include "submodule-config.h"
  22
  23 static int nr_trees;
  24 static int read_empty;
  25 static struct tree *trees[MAX_UNPACK_TREES];
  26
  27 static int list_tree(struct object_id *oid)
  28 {
  29         struct tree *tree;
  30
  31         if (nr_trees >= MAX_UNPACK_TREES)
  32                 die("I cannot read more than %d trees", MAX_UNPACK_TREES);
  33         tree = parse_tree_indirect(oid);
  34         if (!tree)
  35                 return -1;
  36         trees[nr_trees++] = tree;
  37         return 0;
  38 }
  39
  40 static const char * const read_tree_usage[] = {
  41         N_("git read-tree [(-m [--trivial] [--aggressive] | --reset | --prefix=<prefix>)\n"
  42            "              [-u | -i]] [--index-output=<file>] [--no-sparse-checkout]\n"
  43            "              (--empty | <tree-ish1> [<tree-ish2> [<tree-ish3>]])"),
  44         NULL
  45 };
  46
  47 static int index_output_cb(const struct option *opt, const char *arg,
  48                                  int unset)
  49 {
  50         BUG_ON_OPT_NEG(unset);
  51         set_alternate_index_output(arg);
  52         return 0;
  53 }
  54
  55 static int exclude_per_directory_cb(const struct option *opt, const char *arg,
  56                                     int unset)
  57 {
  58         struct unpack_trees_options *opts;
  59
  60         BUG_ON_OPT_NEG(unset);
  61
  62         opts = (struct unpack_trees_options *)opt->value;
  63
  64         if (!opts->update)
  65                 die("--exclude-per-directory is meaningless unless -u");
  66         if (strcmp(arg, ".gitignore"))
  67                 die("--exclude-per-directory argument must be .gitignore");
  68         return 0;
  69 }
  70
  71 static void debug_stage(const char *label, const struct cache_entry *ce,
  72                         struct unpack_trees_options *o)
  73 {
  74         printf("%s ", label);
  75         if (!ce)
  76                 printf("(missing)\n");
  77         else if (ce == o->df_conflict_entry)
  78                 printf("(conflict)\n");
  79         else
  80                 printf("%06o #%d %s %.8s\n",
  81                        ce->ce_mode, ce_stage(ce), ce->name,
  82                        oid_to_hex(&ce->oid));
  83 }
  84
  85 static int debug_merge(const struct cache_entry * const *stages,
  86                        struct unpack_trees_options *o)
  87 {
  88         int i;
  89
  90         printf("* %d-way merge\n", o->merge_size);
  91         debug_stage("index", stages[0], o);
  92         for (i = 1; i <= o->merge_size; i++) {
  93                 char buf[24];
  94                 xsnprintf(buf, sizeof(buf), "ent#%d", i);
  95                 debug_stage(buf, stages[i], o);
  96         }
  97         return 0;
  98 }
  99
 100 static int git_read_tree_config(const char *var, const char *value, void *cb)
 101 {
 102         if (!strcmp(var, "submodule.recurse"))
 103                 return git_default_submodule_config(var, value, cb);
 104
 105         return git_default_config(var, value, cb);
 106 }
 107
 108 int cmd_read_tree(int argc, const char **argv, const char *cmd_prefix)
 109 {
 110         int i, stage = 0;
 111         struct object_id oid;
 112         struct tree_desc t[MAX_UNPACK_TREES];
 113         struct unpack_trees_options opts;
 114         int prefix_set = 0;
 115         struct lock_file lock_file = LOCK_INIT;
 116         const struct option read_tree_options[] = {
 117                 OPT__SUPER_PREFIX(&opts.super_prefix),
 118                 OPT_CALLBACK_F(0, "index-output", NULL, N_("file"),
 119                   N_("write resulting index to <file>"),
 120                   PARSE_OPT_NONEG, index_output_cb),
 121                 OPT_BOOL(0, "empty", &read_empty,
 122                             N_("only empty the index")),
 123                 OPT__VERBOSE(&opts.verbose_update, N_("be verbose")),
 124                 OPT_GROUP(N_("Merging")),
 125                 OPT_BOOL('m', NULL, &opts.merge,
 126                          N_("perform a merge in addition to a read")),
 127                 OPT_BOOL(0, "trivial", &opts.trivial_merges_only,
 128                          N_("3-way merge if no file level merging required")),
 129                 OPT_BOOL(0, "aggressive", &opts.aggressive,
 130                          N_("3-way merge in presence of adds and removes")),
 131                 OPT_BOOL(0, "reset", &opts.reset,
 132                          N_("same as -m, but discard unmerged entries")),
 133                 { OPTION_STRING, 0, "prefix", &opts.prefix, N_("<subdirectory>/"),
 134                   N_("read the tree into the index under <subdirectory>/"),
 135                   PARSE_OPT_NONEG },
 136                 OPT_BOOL('u', NULL, &opts.update,
 137                          N_("update working tree with merge result")),
 138                 OPT_CALLBACK_F(0, "exclude-per-directory", &opts,
 139                   N_("gitignore"),
 140                   N_("allow explicitly ignored files to be overwritten"),
 141                   PARSE_OPT_NONEG, exclude_per_directory_cb),
 142                 OPT_BOOL('i', NULL, &opts.index_only,
 143                          N_("don't check the working tree after merging")),
 144                 OPT__DRY_RUN(&opts.dry_run, N_("don't update the index or the work tree")),
 145                 OPT_BOOL(0, "no-sparse-checkout", &opts.skip_sparse_checkout,
 146                          N_("skip applying sparse checkout filter")),
 147                 OPT_BOOL(0, "debug-unpack", &opts.debug_unpack,
 148                          N_("debug unpack-trees")),
 149                 OPT_CALLBACK_F(0, "recurse-submodules", NULL,
 150                             "checkout", "control recursive updating of submodules",
 151                             PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater),
 152                 OPT__QUIET(&opts.quiet, N_("suppress feedback messages")),
 153                 OPT_END()
 154         };
 155
 156         memset(&opts, 0, sizeof(opts));
 157         opts.head_idx = -1;
 158         opts.src_index = &the_index;
 159         opts.dst_index = &the_index;
 160
 161         git_config(git_read_tree_config, NULL);
 162
 163         argc = parse_options(argc, argv, cmd_prefix, read_tree_options,
 164                              read_tree_usage, 0);
 165
 166         prefix_set = opts.prefix ? 1 : 0;
 167         if (1 < opts.merge + opts.reset + prefix_set)
 168                 die("Which one? -m, --reset, or --prefix?");
 169
 170         /* Prefix should not start with a directory separator */
 171         if (opts.prefix && opts.prefix[0] == '/')
 172                 die("Invalid prefix, prefix cannot start with '/'");
 173
 174         if (opts.reset)
 175                 opts.reset = UNPACK_RESET_OVERWRITE_UNTRACKED;
 176
 177         prepare_repo_settings(the_repository);
 178         the_repository->settings.command_requires_full_index = 0;
 179
 180         repo_hold_locked_index(the_repository, &lock_file, LOCK_DIE_ON_ERROR);
 181
 182         /*
 183          * NEEDSWORK
 184          *
 185          * The old index should be read anyway even if we're going to
 186          * destroy all index entries because we still need to preserve
 187          * certain information such as index version or split-index
 188          * mode.
 189          */
 190
 191         if (opts.reset || opts.merge || opts.prefix) {
 192                 if (repo_read_index_unmerged(the_repository) && (opts.prefix || opts.merge))
 193                         die(_("You need to resolve your current index first"));
 194                 stage = opts.merge = 1;
 195         }
 196         resolve_undo_clear_index(&the_index);
 197
 198         for (i = 0; i < argc; i++) {
 199                 const char *arg = argv[i];
 200
 201                 if (get_oid(arg, &oid))
 202                         die("Not a valid object name %s", arg);
 203                 if (list_tree(&oid) < 0)
 204                         die("failed to unpack tree object %s", arg);
 205                 stage++;
 206         }
 207         if (!nr_trees && !read_empty && !opts.merge)
 208                 warning("read-tree: emptying the index with no arguments is deprecated; use --empty");
 209         else if (nr_trees > 0 && read_empty)
 210                 die("passing trees as arguments contradicts --empty");
 211
 212         if (1 < opts.index_only + opts.update)
 213                 die("-u and -i at the same time makes no sense");
 214         if ((opts.update || opts.index_only) && !opts.merge)
 215                 die("%s is meaningless without -m, --reset, or --prefix",
 216                     opts.update ? "-u" : "-i");
 217         if (opts.update && !opts.reset)
 218                 opts.preserve_ignored = 0;
 219         /* otherwise, opts.preserve_ignored is irrelevant */
 220         if (opts.merge && !opts.index_only)
 221                 setup_work_tree();
 222
 223         if (opts.skip_sparse_checkout)
 224                 ensure_full_index(&the_index);
 225
 226         if (opts.merge) {
 227                 switch (stage - 1) {
 228                 case 0:
 229                         die("you must specify at least one tree to merge");
 230                         break;
 231                 case 1:
 232                         opts.fn = opts.prefix ? bind_merge : oneway_merge;
 233                         break;
 234                 case 2:
 235                         opts.fn = twoway_merge;
 236                         opts.initial_checkout = is_index_unborn(&the_index);
 237                         break;
 238                 case 3:
 239                 default:
 240                         opts.fn = threeway_merge;
 241                         break;
 242                 }
 243
 244                 if (stage - 1 >= 3)
 245                         opts.head_idx = stage - 2;
 246                 else
 247                         opts.head_idx = 1;
 248         }
 249
 250         if (opts.debug_unpack)
 251                 opts.fn = debug_merge;
 252
 253         /* If we're going to prime_cache_tree later, skip cache tree update */
 254         if (nr_trees == 1 && !opts.prefix)
 255                 opts.skip_cache_tree_update = 1;
 256
 257         cache_tree_free(&the_index.cache_tree);
 258         for (i = 0; i < nr_trees; i++) {
 259                 struct tree *tree = trees[i];
 260                 parse_tree(tree);
 261                 init_tree_desc(t+i, tree->buffer, tree->size);
 262         }
 263         if (unpack_trees(nr_trees, t, &opts))
 264                 return 128;
 265
 266         if (opts.debug_unpack || opts.dry_run)
 267                 return 0; /* do not write the index out */
 268
 269         /*
 270          * When reading only one tree (either the most basic form,
 271          * "-m ent" or "--reset ent" form), we can obtain a fully
 272          * valid cache-tree because the index must match exactly
 273          * what came from the tree.
 274          */
 275         if (nr_trees == 1 && !opts.prefix)
 276                 prime_cache_tree(the_repository,
 277                                  the_repository->index,
 278                                  trees[0]);
 279
 280         if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 281                 die("unable to write new index file");
 282         return 0;
 283 }