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_CALLBACK_F(0, "index-output", NULL, N_("file"),
 118                   N_("write resulting index to <file>"),
 119                   PARSE_OPT_NONEG, index_output_cb),
 120                 OPT_BOOL(0, "empty", &read_empty,
 121                             N_("only empty the index")),
 122                 OPT__VERBOSE(&opts.verbose_update, N_("be verbose")),
 123                 OPT_GROUP(N_("Merging")),
 124                 OPT_BOOL('m', NULL, &opts.merge,
 125                          N_("perform a merge in addition to a read")),
 126                 OPT_BOOL(0, "trivial", &opts.trivial_merges_only,
 127                          N_("3-way merge if no file level merging required")),
 128                 OPT_BOOL(0, "aggressive", &opts.aggressive,
 129                          N_("3-way merge in presence of adds and removes")),
 130                 OPT_BOOL(0, "reset", &opts.reset,
 131                          N_("same as -m, but discard unmerged entries")),
 132                 { OPTION_STRING, 0, "prefix", &opts.prefix, N_("<subdirectory>/"),
 133                   N_("read the tree into the index under <subdirectory>/"),
 134                   PARSE_OPT_NONEG },
 135                 OPT_BOOL('u', NULL, &opts.update,
 136                          N_("update working tree with merge result")),
 137                 OPT_CALLBACK_F(0, "exclude-per-directory", &opts,
 138                   N_("gitignore"),
 139                   N_("allow explicitly ignored files to be overwritten"),
 140                   PARSE_OPT_NONEG, exclude_per_directory_cb),
 141                 OPT_BOOL('i', NULL, &opts.index_only,
 142                          N_("don't check the working tree after merging")),
 143                 OPT__DRY_RUN(&opts.dry_run, N_("don't update the index or the work tree")),
 144                 OPT_BOOL(0, "no-sparse-checkout", &opts.skip_sparse_checkout,
 145                          N_("skip applying sparse checkout filter")),
 146                 OPT_BOOL(0, "debug-unpack", &opts.debug_unpack,
 147                          N_("debug unpack-trees")),
 148                 OPT_CALLBACK_F(0, "recurse-submodules", NULL,
 149                             "checkout", "control recursive updating of submodules",
 150                             PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater),
 151                 OPT__QUIET(&opts.quiet, N_("suppress feedback messages")),
 152                 OPT_END()
 153         };
 154
 155         memset(&opts, 0, sizeof(opts));
 156         opts.head_idx = -1;
 157         opts.src_index = &the_index;
 158         opts.dst_index = &the_index;
 159
 160         git_config(git_read_tree_config, NULL);
 161
 162         argc = parse_options(argc, argv, cmd_prefix, read_tree_options,
 163                              read_tree_usage, 0);
 164
 165         prefix_set = opts.prefix ? 1 : 0;
 166         if (1 < opts.merge + opts.reset + prefix_set)
 167                 die("Which one? -m, --reset, or --prefix?");
 168
 169         /* Prefix should not start with a directory separator */
 170         if (opts.prefix && opts.prefix[0] == '/')
 171                 die("Invalid prefix, prefix cannot start with '/'");
 172
 173         if (opts.reset)
 174                 opts.reset = UNPACK_RESET_OVERWRITE_UNTRACKED;
 175
 176         prepare_repo_settings(the_repository);
 177         the_repository->settings.command_requires_full_index = 0;
 178
 179         repo_hold_locked_index(the_repository, &lock_file, LOCK_DIE_ON_ERROR);
 180
 181         /*
 182          * NEEDSWORK
 183          *
 184          * The old index should be read anyway even if we're going to
 185          * destroy all index entries because we still need to preserve
 186          * certain information such as index version or split-index
 187          * mode.
 188          */
 189
 190         if (opts.reset || opts.merge || opts.prefix) {
 191                 if (repo_read_index_unmerged(the_repository) && (opts.prefix || opts.merge))
 192                         die(_("You need to resolve your current index first"));
 193                 stage = opts.merge = 1;
 194         }
 195         resolve_undo_clear_index(&the_index);
 196
 197         for (i = 0; i < argc; i++) {
 198                 const char *arg = argv[i];
 199
 200                 if (get_oid(arg, &oid))
 201                         die("Not a valid object name %s", arg);
 202                 if (list_tree(&oid) < 0)
 203                         die("failed to unpack tree object %s", arg);
 204                 stage++;
 205         }
 206         if (!nr_trees && !read_empty && !opts.merge)
 207                 warning("read-tree: emptying the index with no arguments is deprecated; use --empty");
 208         else if (nr_trees > 0 && read_empty)
 209                 die("passing trees as arguments contradicts --empty");
 210
 211         if (1 < opts.index_only + opts.update)
 212                 die("-u and -i at the same time makes no sense");
 213         if ((opts.update || opts.index_only) && !opts.merge)
 214                 die("%s is meaningless without -m, --reset, or --prefix",
 215                     opts.update ? "-u" : "-i");
 216         if (opts.update && !opts.reset)
 217                 opts.preserve_ignored = 0;
 218         /* otherwise, opts.preserve_ignored is irrelevant */
 219         if (opts.merge && !opts.index_only)
 220                 setup_work_tree();
 221
 222         if (opts.skip_sparse_checkout)
 223                 ensure_full_index(&the_index);
 224
 225         if (opts.merge) {
 226                 switch (stage - 1) {
 227                 case 0:
 228                         die("you must specify at least one tree to merge");
 229                         break;
 230                 case 1:
 231                         opts.fn = opts.prefix ? bind_merge : oneway_merge;
 232                         break;
 233                 case 2:
 234                         opts.fn = twoway_merge;
 235                         opts.initial_checkout = is_index_unborn(&the_index);
 236                         break;
 237                 case 3:
 238                 default:
 239                         opts.fn = threeway_merge;
 240                         break;
 241                 }
 242
 243                 if (stage - 1 >= 3)
 244                         opts.head_idx = stage - 2;
 245                 else
 246                         opts.head_idx = 1;
 247         }
 248
 249         if (opts.debug_unpack)
 250                 opts.fn = debug_merge;
 251
 252         /* If we're going to prime_cache_tree later, skip cache tree update */
 253         if (nr_trees == 1 && !opts.prefix)
 254                 opts.skip_cache_tree_update = 1;
 255
 256         cache_tree_free(&the_index.cache_tree);
 257         for (i = 0; i < nr_trees; i++) {
 258                 struct tree *tree = trees[i];
 259                 parse_tree(tree);
 260                 init_tree_desc(t+i, tree->buffer, tree->size);
 261         }
 262         if (unpack_trees(nr_trees, t, &opts))
 263                 return 128;
 264
 265         if (opts.debug_unpack || opts.dry_run)
 266                 return 0; /* do not write the index out */
 267
 268         /*
 269          * When reading only one tree (either the most basic form,
 270          * "-m ent" or "--reset ent" form), we can obtain a fully
 271          * valid cache-tree because the index must match exactly
 272          * what came from the tree.
 273          */
 274         if (nr_trees == 1 && !opts.prefix)
 275                 prime_cache_tree(the_repository,
 276                                  the_repository->index,
 277                                  trees[0]);
 278
 279         if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 280                 die("unable to write new index file");
 281         return 0;
 282 }