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