builtin/read-tree.c

   1 /*
   2  * GIT - The information manager from hell
   3  *
   4  * Copyright (C) Linus Torvalds, 2005
   5  */
   6
   7 #include "builtin.h"
   8 #include "config.h"
   9 #include "gettext.h"
  10 #include "hex.h"
  11 #include "lockfile.h"
  12 #include "object.h"
  13 #include "object-name.h"
  14 #include "tree.h"
  15 #include "tree-walk.h"
  16 #include "cache-tree.h"
  17 #include "unpack-trees.h"
  18 #include "parse-options.h"
  19 #include "repository.h"
  20 #include "resolve-undo.h"
  21 #include "setup.h"
  22 #include "sparse-index.h"
  23 #include "submodule.h"
  24
  25 static int nr_trees;
  26 static int read_empty;
  27 static struct tree *trees[MAX_UNPACK_TREES];
  28
  29 static int list_tree(struct object_id *oid)
  30 {
  31         struct tree *tree;
  32
  33         if (nr_trees >= MAX_UNPACK_TREES)
  34                 die("I cannot read more than %d trees", MAX_UNPACK_TREES);
  35         tree = parse_tree_indirect(oid);
  36         if (!tree)
  37                 return -1;
  38         trees[nr_trees++] = tree;
  39         return 0;
  40 }
  41
  42 static const char * const read_tree_usage[] = {
  43         N_("git read-tree [(-m [--trivial] [--aggressive] | --reset | --prefix=<prefix>)\n"
  44            "              [-u | -i]] [--index-output=<file>] [--no-sparse-checkout]\n"
  45            "              (--empty | <tree-ish1> [<tree-ish2> [<tree-ish3>]])"),
  46         NULL
  47 };
  48
  49 static int index_output_cb(const struct option *opt UNUSED, const char *arg,
  50                                  int unset)
  51 {
  52         BUG_ON_OPT_NEG(unset);
  53         set_alternate_index_output(arg);
  54         return 0;
  55 }
  56
  57 static int exclude_per_directory_cb(const struct option *opt, const char *arg,
  58                                     int unset)
  59 {
  60         struct unpack_trees_options *opts;
  61
  62         BUG_ON_OPT_NEG(unset);
  63
  64         opts = (struct unpack_trees_options *)opt->value;
  65
  66         if (!opts->update)
  67                 die("--exclude-per-directory is meaningless unless -u");
  68         if (strcmp(arg, ".gitignore"))
  69                 die("--exclude-per-directory argument must be .gitignore");
  70         return 0;
  71 }
  72
  73 static void debug_stage(const char *label, const struct cache_entry *ce,
  74                         struct unpack_trees_options *o)
  75 {
  76         printf("%s ", label);
  77         if (!ce)
  78                 printf("(missing)\n");
  79         else if (ce == o->df_conflict_entry)
  80                 printf("(conflict)\n");
  81         else
  82                 printf("%06o #%d %s %.8s\n",
  83                        ce->ce_mode, ce_stage(ce), ce->name,
  84                        oid_to_hex(&ce->oid));
  85 }
  86
  87 static int debug_merge(const struct cache_entry * const *stages,
  88                        struct unpack_trees_options *o)
  89 {
  90         int i;
  91
  92         printf("* %d-way merge\n", o->internal.merge_size);
  93         debug_stage("index", stages[0], o);
  94         for (i = 1; i <= o->internal.merge_size; i++) {
  95                 char buf[24];
  96                 xsnprintf(buf, sizeof(buf), "ent#%d", i);
  97                 debug_stage(buf, stages[i], o);
  98         }
  99         return 0;
 100 }
 101
 102 static int git_read_tree_config(const char *var, const char *value,
 103                                 const struct config_context *ctx, void *cb)
 104 {
 105         if (!strcmp(var, "submodule.recurse"))
 106                 return git_default_submodule_config(var, value, cb);
 107
 108         return git_default_config(var, value, ctx, cb);
 109 }
 110
 111 int cmd_read_tree(int argc, const char **argv, const char *cmd_prefix)
 112 {
 113         int i, stage = 0;
 114         struct object_id oid;
 115         struct tree_desc t[MAX_UNPACK_TREES];
 116         struct unpack_trees_options opts;
 117         int prefix_set = 0;
 118         struct lock_file lock_file = LOCK_INIT;
 119         const struct option read_tree_options[] = {
 120                 OPT__SUPER_PREFIX(&opts.super_prefix),
 121                 OPT_CALLBACK_F(0, "index-output", NULL, N_("file"),
 122                   N_("write resulting index to <file>"),
 123                   PARSE_OPT_NONEG, index_output_cb),
 124                 OPT_BOOL(0, "empty", &read_empty,
 125                             N_("only empty the index")),
 126                 OPT__VERBOSE(&opts.verbose_update, N_("be verbose")),
 127                 OPT_GROUP(N_("Merging")),
 128                 OPT_BOOL('m', NULL, &opts.merge,
 129                          N_("perform a merge in addition to a read")),
 130                 OPT_BOOL(0, "trivial", &opts.trivial_merges_only,
 131                          N_("3-way merge if no file level merging required")),
 132                 OPT_BOOL(0, "aggressive", &opts.aggressive,
 133                          N_("3-way merge in presence of adds and removes")),
 134                 OPT_BOOL(0, "reset", &opts.reset,
 135                          N_("same as -m, but discard unmerged entries")),
 136                 { OPTION_STRING, 0, "prefix", &opts.prefix, N_("<subdirectory>/"),
 137                   N_("read the tree into the index under <subdirectory>/"),
 138                   PARSE_OPT_NONEG },
 139                 OPT_BOOL('u', NULL, &opts.update,
 140                          N_("update working tree with merge result")),
 141                 OPT_CALLBACK_F(0, "exclude-per-directory", &opts,
 142                   N_("gitignore"),
 143                   N_("allow explicitly ignored files to be overwritten"),
 144                   PARSE_OPT_NONEG, exclude_per_directory_cb),
 145                 OPT_BOOL('i', NULL, &opts.index_only,
 146                          N_("don't check the working tree after merging")),
 147                 OPT__DRY_RUN(&opts.dry_run, N_("don't update the index or the work tree")),
 148                 OPT_BOOL(0, "no-sparse-checkout", &opts.skip_sparse_checkout,
 149                          N_("skip applying sparse checkout filter")),
 150                 OPT_BOOL(0, "debug-unpack", &opts.internal.debug_unpack,
 151                          N_("debug unpack-trees")),
 152                 OPT_CALLBACK_F(0, "recurse-submodules", NULL,
 153                             "checkout", "control recursive updating of submodules",
 154                             PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater),
 155                 OPT__QUIET(&opts.quiet, N_("suppress feedback messages")),
 156                 OPT_END()
 157         };
 158
 159         memset(&opts, 0, sizeof(opts));
 160         opts.head_idx = -1;
 161         opts.src_index = the_repository->index;
 162         opts.dst_index = the_repository->index;
 163
 164         git_config(git_read_tree_config, NULL);
 165
 166         argc = parse_options(argc, argv, cmd_prefix, read_tree_options,
 167                              read_tree_usage, 0);
 168
 169         prefix_set = opts.prefix ? 1 : 0;
 170         if (1 < opts.merge + opts.reset + prefix_set)
 171                 die("Which one? -m, --reset, or --prefix?");
 172
 173         /* Prefix should not start with a directory separator */
 174         if (opts.prefix && opts.prefix[0] == '/')
 175                 die("Invalid prefix, prefix cannot start with '/'");
 176
 177         if (opts.reset)
 178                 opts.reset = UNPACK_RESET_OVERWRITE_UNTRACKED;
 179
 180         prepare_repo_settings(the_repository);
 181         the_repository->settings.command_requires_full_index = 0;
 182
 183         repo_hold_locked_index(the_repository, &lock_file, LOCK_DIE_ON_ERROR);
 184
 185         /*
 186          * NEEDSWORK
 187          *
 188          * The old index should be read anyway even if we're going to
 189          * destroy all index entries because we still need to preserve
 190          * certain information such as index version or split-index
 191          * mode.
 192          */
 193
 194         if (opts.reset || opts.merge || opts.prefix) {
 195                 if (repo_read_index_unmerged(the_repository) && (opts.prefix || opts.merge))
 196                         die(_("You need to resolve your current index first"));
 197                 stage = opts.merge = 1;
 198         }
 199         resolve_undo_clear_index(the_repository->index);
 200
 201         for (i = 0; i < argc; i++) {
 202                 const char *arg = argv[i];
 203
 204                 if (repo_get_oid(the_repository, arg, &oid))
 205                         die("Not a valid object name %s", arg);
 206                 if (list_tree(&oid) < 0)
 207                         die("failed to unpack tree object %s", arg);
 208                 stage++;
 209         }
 210         if (!nr_trees && !read_empty && !opts.merge)
 211                 warning("read-tree: emptying the index with no arguments is deprecated; use --empty");
 212         else if (nr_trees > 0 && read_empty)
 213                 die("passing trees as arguments contradicts --empty");
 214
 215         if (1 < opts.index_only + opts.update)
 216                 die("-u and -i at the same time makes no sense");
 217         if ((opts.update || opts.index_only) && !opts.merge)
 218                 die("%s is meaningless without -m, --reset, or --prefix",
 219                     opts.update ? "-u" : "-i");
 220         if (opts.update && !opts.reset)
 221                 opts.preserve_ignored = 0;
 222         /* otherwise, opts.preserve_ignored is irrelevant */
 223         if (opts.merge && !opts.index_only)
 224                 setup_work_tree();
 225
 226         if (opts.skip_sparse_checkout)
 227                 ensure_full_index(the_repository->index);
 228
 229         if (opts.merge) {
 230                 switch (stage - 1) {
 231                 case 0:
 232                         die("you must specify at least one tree to merge");
 233                         break;
 234                 case 1:
 235                         opts.fn = opts.prefix ? bind_merge : oneway_merge;
 236                         break;
 237                 case 2:
 238                         opts.fn = twoway_merge;
 239                         opts.initial_checkout = is_index_unborn(the_repository->index);
 240                         break;
 241                 case 3:
 242                 default:
 243                         opts.fn = threeway_merge;
 244                         break;
 245                 }
 246
 247                 if (stage - 1 >= 3)
 248                         opts.head_idx = stage - 2;
 249                 else
 250                         opts.head_idx = 1;
 251         }
 252
 253         if (opts.internal.debug_unpack)
 254                 opts.fn = debug_merge;
 255
 256         /* If we're going to prime_cache_tree later, skip cache tree update */
 257         if (nr_trees == 1 && !opts.prefix)
 258                 opts.skip_cache_tree_update = 1;
 259
 260         cache_tree_free(&the_repository->index->cache_tree);
 261         for (i = 0; i < nr_trees; i++) {
 262                 struct tree *tree = trees[i];
 263                 if (parse_tree(tree) < 0)
 264                         return 128;
 265                 init_tree_desc(t+i, &tree->object.oid, 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_repository->index, &lock_file, COMMIT_LOCK))
 285                 die("unable to write new index file");
 286         return 0;
 287 }