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 "builtin.h"
   9 #include "config.h"
  10 #include "gettext.h"
  11 #include "hex.h"
  12 #include "lockfile.h"
  13 #include "object.h"
  14 #include "object-name.h"
  15 #include "tree.h"
  16 #include "tree-walk.h"
  17 #include "cache-tree.h"
  18 #include "unpack-trees.h"
  19 #include "parse-options.h"
  20 #include "repository.h"
  21 #include "resolve-undo.h"
  22 #include "setup.h"
  23 #include "sparse-index.h"
  24 #include "submodule.h"
  25
  26 static int nr_trees;
  27 static int read_empty;
  28 static struct tree *trees[MAX_UNPACK_TREES];
  29
  30 static int list_tree(struct object_id *oid)
  31 {
  32         struct tree *tree;
  33
  34         if (nr_trees >= MAX_UNPACK_TREES)
  35                 die("I cannot read more than %d trees", MAX_UNPACK_TREES);
  36         tree = parse_tree_indirect(oid);
  37         if (!tree)
  38                 return -1;
  39         trees[nr_trees++] = tree;
  40         return 0;
  41 }
  42
  43 static const char * const read_tree_usage[] = {
  44         N_("git read-tree [(-m [--trivial] [--aggressive] | --reset | --prefix=<prefix>)\n"
  45            "              [-u | -i]] [--index-output=<file>] [--no-sparse-checkout]\n"
  46            "              (--empty | <tree-ish1> [<tree-ish2> [<tree-ish3>]])"),
  47         NULL
  48 };
  49
  50 static int index_output_cb(const struct option *opt UNUSED, const char *arg,
  51                                  int unset)
  52 {
  53         BUG_ON_OPT_NEG(unset);
  54         set_alternate_index_output(arg);
  55         return 0;
  56 }
  57
  58 static int exclude_per_directory_cb(const struct option *opt, const char *arg,
  59                                     int unset)
  60 {
  61         struct unpack_trees_options *opts;
  62
  63         BUG_ON_OPT_NEG(unset);
  64
  65         opts = (struct unpack_trees_options *)opt->value;
  66
  67         if (!opts->update)
  68                 die("--exclude-per-directory is meaningless unless -u");
  69         if (strcmp(arg, ".gitignore"))
  70                 die("--exclude-per-directory argument must be .gitignore");
  71         return 0;
  72 }
  73
  74 static void debug_stage(const char *label, const struct cache_entry *ce,
  75                         struct unpack_trees_options *o)
  76 {
  77         printf("%s ", label);
  78         if (!ce)
  79                 printf("(missing)\n");
  80         else if (ce == o->df_conflict_entry)
  81                 printf("(conflict)\n");
  82         else
  83                 printf("%06o #%d %s %.8s\n",
  84                        ce->ce_mode, ce_stage(ce), ce->name,
  85                        oid_to_hex(&ce->oid));
  86 }
  87
  88 static int debug_merge(const struct cache_entry * const *stages,
  89                        struct unpack_trees_options *o)
  90 {
  91         int i;
  92
  93         printf("* %d-way merge\n", o->internal.merge_size);
  94         debug_stage("index", stages[0], o);
  95         for (i = 1; i <= o->internal.merge_size; i++) {
  96                 char buf[24];
  97                 xsnprintf(buf, sizeof(buf), "ent#%d", i);
  98                 debug_stage(buf, stages[i], o);
  99         }
 100         return 0;
 101 }
 102
 103 static int git_read_tree_config(const char *var, const char *value,
 104                                 const struct config_context *ctx, void *cb)
 105 {
 106         if (!strcmp(var, "submodule.recurse"))
 107                 return git_default_submodule_config(var, value, cb);
 108
 109         return git_default_config(var, value, ctx, cb);
 110 }
 111
 112 int cmd_read_tree(int argc, const char **argv, const char *cmd_prefix)
 113 {
 114         int i, stage = 0;
 115         struct object_id oid;
 116         struct tree_desc t[MAX_UNPACK_TREES];
 117         struct unpack_trees_options opts;
 118         int prefix_set = 0;
 119         struct lock_file lock_file = LOCK_INIT;
 120         const struct option read_tree_options[] = {
 121                 OPT__SUPER_PREFIX(&opts.super_prefix),
 122                 OPT_CALLBACK_F(0, "index-output", NULL, N_("file"),
 123                   N_("write resulting index to <file>"),
 124                   PARSE_OPT_NONEG, index_output_cb),
 125                 OPT_BOOL(0, "empty", &read_empty,
 126                             N_("only empty the index")),
 127                 OPT__VERBOSE(&opts.verbose_update, N_("be verbose")),
 128                 OPT_GROUP(N_("Merging")),
 129                 OPT_BOOL('m', NULL, &opts.merge,
 130                          N_("perform a merge in addition to a read")),
 131                 OPT_BOOL(0, "trivial", &opts.trivial_merges_only,
 132                          N_("3-way merge if no file level merging required")),
 133                 OPT_BOOL(0, "aggressive", &opts.aggressive,
 134                          N_("3-way merge in presence of adds and removes")),
 135                 OPT_BOOL(0, "reset", &opts.reset,
 136                          N_("same as -m, but discard unmerged entries")),
 137                 { OPTION_STRING, 0, "prefix", &opts.prefix, N_("<subdirectory>/"),
 138                   N_("read the tree into the index under <subdirectory>/"),
 139                   PARSE_OPT_NONEG },
 140                 OPT_BOOL('u', NULL, &opts.update,
 141                          N_("update working tree with merge result")),
 142                 OPT_CALLBACK_F(0, "exclude-per-directory", &opts,
 143                   N_("gitignore"),
 144                   N_("allow explicitly ignored files to be overwritten"),
 145                   PARSE_OPT_NONEG, exclude_per_directory_cb),
 146                 OPT_BOOL('i', NULL, &opts.index_only,
 147                          N_("don't check the working tree after merging")),
 148                 OPT__DRY_RUN(&opts.dry_run, N_("don't update the index or the work tree")),
 149                 OPT_BOOL(0, "no-sparse-checkout", &opts.skip_sparse_checkout,
 150                          N_("skip applying sparse checkout filter")),
 151                 OPT_BOOL(0, "debug-unpack", &opts.internal.debug_unpack,
 152                          N_("debug unpack-trees")),
 153                 OPT_CALLBACK_F(0, "recurse-submodules", NULL,
 154                             "checkout", "control recursive updating of submodules",
 155                             PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater),
 156                 OPT__QUIET(&opts.quiet, N_("suppress feedback messages")),
 157                 OPT_END()
 158         };
 159
 160         memset(&opts, 0, sizeof(opts));
 161         opts.head_idx = -1;
 162         opts.src_index = &the_index;
 163         opts.dst_index = &the_index;
 164
 165         git_config(git_read_tree_config, NULL);
 166
 167         argc = parse_options(argc, argv, cmd_prefix, read_tree_options,
 168                              read_tree_usage, 0);
 169
 170         prefix_set = opts.prefix ? 1 : 0;
 171         if (1 < opts.merge + opts.reset + prefix_set)
 172                 die("Which one? -m, --reset, or --prefix?");
 173
 174         /* Prefix should not start with a directory separator */
 175         if (opts.prefix && opts.prefix[0] == '/')
 176                 die("Invalid prefix, prefix cannot start with '/'");
 177
 178         if (opts.reset)
 179                 opts.reset = UNPACK_RESET_OVERWRITE_UNTRACKED;
 180
 181         prepare_repo_settings(the_repository);
 182         the_repository->settings.command_requires_full_index = 0;
 183
 184         repo_hold_locked_index(the_repository, &lock_file, LOCK_DIE_ON_ERROR);
 185
 186         /*
 187          * NEEDSWORK
 188          *
 189          * The old index should be read anyway even if we're going to
 190          * destroy all index entries because we still need to preserve
 191          * certain information such as index version or split-index
 192          * mode.
 193          */
 194
 195         if (opts.reset || opts.merge || opts.prefix) {
 196                 if (repo_read_index_unmerged(the_repository) && (opts.prefix || opts.merge))
 197                         die(_("You need to resolve your current index first"));
 198                 stage = opts.merge = 1;
 199         }
 200         resolve_undo_clear_index(&the_index);
 201
 202         for (i = 0; i < argc; i++) {
 203                 const char *arg = argv[i];
 204
 205                 if (repo_get_oid(the_repository, arg, &oid))
 206                         die("Not a valid object name %s", arg);
 207                 if (list_tree(&oid) < 0)
 208                         die("failed to unpack tree object %s", arg);
 209                 stage++;
 210         }
 211         if (!nr_trees && !read_empty && !opts.merge)
 212                 warning("read-tree: emptying the index with no arguments is deprecated; use --empty");
 213         else if (nr_trees > 0 && read_empty)
 214                 die("passing trees as arguments contradicts --empty");
 215
 216         if (1 < opts.index_only + opts.update)
 217                 die("-u and -i at the same time makes no sense");
 218         if ((opts.update || opts.index_only) && !opts.merge)
 219                 die("%s is meaningless without -m, --reset, or --prefix",
 220                     opts.update ? "-u" : "-i");
 221         if (opts.update && !opts.reset)
 222                 opts.preserve_ignored = 0;
 223         /* otherwise, opts.preserve_ignored is irrelevant */
 224         if (opts.merge && !opts.index_only)
 225                 setup_work_tree();
 226
 227         if (opts.skip_sparse_checkout)
 228                 ensure_full_index(&the_index);
 229
 230         if (opts.merge) {
 231                 switch (stage - 1) {
 232                 case 0:
 233                         die("you must specify at least one tree to merge");
 234                         break;
 235                 case 1:
 236                         opts.fn = opts.prefix ? bind_merge : oneway_merge;
 237                         break;
 238                 case 2:
 239                         opts.fn = twoway_merge;
 240                         opts.initial_checkout = is_index_unborn(&the_index);
 241                         break;
 242                 case 3:
 243                 default:
 244                         opts.fn = threeway_merge;
 245                         break;
 246                 }
 247
 248                 if (stage - 1 >= 3)
 249                         opts.head_idx = stage - 2;
 250                 else
 251                         opts.head_idx = 1;
 252         }
 253
 254         if (opts.internal.debug_unpack)
 255                 opts.fn = debug_merge;
 256
 257         /* If we're going to prime_cache_tree later, skip cache tree update */
 258         if (nr_trees == 1 && !opts.prefix)
 259                 opts.skip_cache_tree_update = 1;
 260
 261         cache_tree_free(&the_index.cache_tree);
 262         for (i = 0; i < nr_trees; i++) {
 263                 struct tree *tree = trees[i];
 264                 parse_tree(tree);
 265                 init_tree_desc(t+i, tree->buffer, tree->size);
 266         }
 267         if (unpack_trees(nr_trees, t, &opts))
 268                 return 128;
 269
 270         if (opts.internal.debug_unpack || opts.dry_run)
 271                 return 0; /* do not write the index out */
 272
 273         /*
 274          * When reading only one tree (either the most basic form,
 275          * "-m ent" or "--reset ent" form), we can obtain a fully
 276          * valid cache-tree because the index must match exactly
 277          * what came from the tree.
 278          */
 279         if (nr_trees == 1 && !opts.prefix)
 280                 prime_cache_tree(the_repository,
 281                                  the_repository->index,
 282                                  trees[0]);
 283
 284         if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 285                 die("unable to write new index file");
 286         return 0;
 287 }