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 "dir.h"
  20 #include "parse-options.h"
  21 #include "repository.h"
  22 #include "resolve-undo.h"
  23 #include "setup.h"
  24 #include "sparse-index.h"
  25 #include "submodule.h"
  26 #include "submodule-config.h"
  27
  28 static int nr_trees;
  29 static int read_empty;
  30 static struct tree *trees[MAX_UNPACK_TREES];
  31
  32 static int list_tree(struct object_id *oid)
  33 {
  34         struct tree *tree;
  35
  36         if (nr_trees >= MAX_UNPACK_TREES)
  37                 die("I cannot read more than %d trees", MAX_UNPACK_TREES);
  38         tree = parse_tree_indirect(oid);
  39         if (!tree)
  40                 return -1;
  41         trees[nr_trees++] = tree;
  42         return 0;
  43 }
  44
  45 static const char * const read_tree_usage[] = {
  46         N_("git read-tree [(-m [--trivial] [--aggressive] | --reset | --prefix=<prefix>)\n"
  47            "              [-u | -i]] [--index-output=<file>] [--no-sparse-checkout]\n"
  48            "              (--empty | <tree-ish1> [<tree-ish2> [<tree-ish3>]])"),
  49         NULL
  50 };
  51
  52 static int index_output_cb(const struct option *opt UNUSED, const char *arg,
  53                                  int unset)
  54 {
  55         BUG_ON_OPT_NEG(unset);
  56         set_alternate_index_output(arg);
  57         return 0;
  58 }
  59
  60 static int exclude_per_directory_cb(const struct option *opt, const char *arg,
  61                                     int unset)
  62 {
  63         struct unpack_trees_options *opts;
  64
  65         BUG_ON_OPT_NEG(unset);
  66
  67         opts = (struct unpack_trees_options *)opt->value;
  68
  69         if (!opts->update)
  70                 die("--exclude-per-directory is meaningless unless -u");
  71         if (strcmp(arg, ".gitignore"))
  72                 die("--exclude-per-directory argument must be .gitignore");
  73         return 0;
  74 }
  75
  76 static void debug_stage(const char *label, const struct cache_entry *ce,
  77                         struct unpack_trees_options *o)
  78 {
  79         printf("%s ", label);
  80         if (!ce)
  81                 printf("(missing)\n");
  82         else if (ce == o->df_conflict_entry)
  83                 printf("(conflict)\n");
  84         else
  85                 printf("%06o #%d %s %.8s\n",
  86                        ce->ce_mode, ce_stage(ce), ce->name,
  87                        oid_to_hex(&ce->oid));
  88 }
  89
  90 static int debug_merge(const struct cache_entry * const *stages,
  91                        struct unpack_trees_options *o)
  92 {
  93         int i;
  94
  95         printf("* %d-way merge\n", o->internal.merge_size);
  96         debug_stage("index", stages[0], o);
  97         for (i = 1; i <= o->internal.merge_size; i++) {
  98                 char buf[24];
  99                 xsnprintf(buf, sizeof(buf), "ent#%d", i);
 100                 debug_stage(buf, stages[i], o);
 101         }
 102         return 0;
 103 }
 104
 105 static int git_read_tree_config(const char *var, const char *value,
 106                                 const struct config_context *ctx, void *cb)
 107 {
 108         if (!strcmp(var, "submodule.recurse"))
 109                 return git_default_submodule_config(var, value, cb);
 110
 111         return git_default_config(var, value, ctx, cb);
 112 }
 113
 114 int cmd_read_tree(int argc, const char **argv, const char *cmd_prefix)
 115 {
 116         int i, stage = 0;
 117         struct object_id oid;
 118         struct tree_desc t[MAX_UNPACK_TREES];
 119         struct unpack_trees_options opts;
 120         int prefix_set = 0;
 121         struct lock_file lock_file = LOCK_INIT;
 122         const struct option read_tree_options[] = {
 123                 OPT__SUPER_PREFIX(&opts.super_prefix),
 124                 OPT_CALLBACK_F(0, "index-output", NULL, N_("file"),
 125                   N_("write resulting index to <file>"),
 126                   PARSE_OPT_NONEG, index_output_cb),
 127                 OPT_BOOL(0, "empty", &read_empty,
 128                             N_("only empty the index")),
 129                 OPT__VERBOSE(&opts.verbose_update, N_("be verbose")),
 130                 OPT_GROUP(N_("Merging")),
 131                 OPT_BOOL('m', NULL, &opts.merge,
 132                          N_("perform a merge in addition to a read")),
 133                 OPT_BOOL(0, "trivial", &opts.trivial_merges_only,
 134                          N_("3-way merge if no file level merging required")),
 135                 OPT_BOOL(0, "aggressive", &opts.aggressive,
 136                          N_("3-way merge in presence of adds and removes")),
 137                 OPT_BOOL(0, "reset", &opts.reset,
 138                          N_("same as -m, but discard unmerged entries")),
 139                 { OPTION_STRING, 0, "prefix", &opts.prefix, N_("<subdirectory>/"),
 140                   N_("read the tree into the index under <subdirectory>/"),
 141                   PARSE_OPT_NONEG },
 142                 OPT_BOOL('u', NULL, &opts.update,
 143                          N_("update working tree with merge result")),
 144                 OPT_CALLBACK_F(0, "exclude-per-directory", &opts,
 145                   N_("gitignore"),
 146                   N_("allow explicitly ignored files to be overwritten"),
 147                   PARSE_OPT_NONEG, exclude_per_directory_cb),
 148                 OPT_BOOL('i', NULL, &opts.index_only,
 149                          N_("don't check the working tree after merging")),
 150                 OPT__DRY_RUN(&opts.dry_run, N_("don't update the index or the work tree")),
 151                 OPT_BOOL(0, "no-sparse-checkout", &opts.skip_sparse_checkout,
 152                          N_("skip applying sparse checkout filter")),
 153                 OPT_BOOL(0, "debug-unpack", &opts.internal.debug_unpack,
 154                          N_("debug unpack-trees")),
 155                 OPT_CALLBACK_F(0, "recurse-submodules", NULL,
 156                             "checkout", "control recursive updating of submodules",
 157                             PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater),
 158                 OPT__QUIET(&opts.quiet, N_("suppress feedback messages")),
 159                 OPT_END()
 160         };
 161
 162         memset(&opts, 0, sizeof(opts));
 163         opts.head_idx = -1;
 164         opts.src_index = &the_index;
 165         opts.dst_index = &the_index;
 166
 167         git_config(git_read_tree_config, NULL);
 168
 169         argc = parse_options(argc, argv, cmd_prefix, read_tree_options,
 170                              read_tree_usage, 0);
 171
 172         prefix_set = opts.prefix ? 1 : 0;
 173         if (1 < opts.merge + opts.reset + prefix_set)
 174                 die("Which one? -m, --reset, or --prefix?");
 175
 176         /* Prefix should not start with a directory separator */
 177         if (opts.prefix && opts.prefix[0] == '/')
 178                 die("Invalid prefix, prefix cannot start with '/'");
 179
 180         if (opts.reset)
 181                 opts.reset = UNPACK_RESET_OVERWRITE_UNTRACKED;
 182
 183         prepare_repo_settings(the_repository);
 184         the_repository->settings.command_requires_full_index = 0;
 185
 186         repo_hold_locked_index(the_repository, &lock_file, LOCK_DIE_ON_ERROR);
 187
 188         /*
 189          * NEEDSWORK
 190          *
 191          * The old index should be read anyway even if we're going to
 192          * destroy all index entries because we still need to preserve
 193          * certain information such as index version or split-index
 194          * mode.
 195          */
 196
 197         if (opts.reset || opts.merge || opts.prefix) {
 198                 if (repo_read_index_unmerged(the_repository) && (opts.prefix || opts.merge))
 199                         die(_("You need to resolve your current index first"));
 200                 stage = opts.merge = 1;
 201         }
 202         resolve_undo_clear_index(&the_index);
 203
 204         for (i = 0; i < argc; i++) {
 205                 const char *arg = argv[i];
 206
 207                 if (repo_get_oid(the_repository, arg, &oid))
 208                         die("Not a valid object name %s", arg);
 209                 if (list_tree(&oid) < 0)
 210                         die("failed to unpack tree object %s", arg);
 211                 stage++;
 212         }
 213         if (!nr_trees && !read_empty && !opts.merge)
 214                 warning("read-tree: emptying the index with no arguments is deprecated; use --empty");
 215         else if (nr_trees > 0 && read_empty)
 216                 die("passing trees as arguments contradicts --empty");
 217
 218         if (1 < opts.index_only + opts.update)
 219                 die("-u and -i at the same time makes no sense");
 220         if ((opts.update || opts.index_only) && !opts.merge)
 221                 die("%s is meaningless without -m, --reset, or --prefix",
 222                     opts.update ? "-u" : "-i");
 223         if (opts.update && !opts.reset)
 224                 opts.preserve_ignored = 0;
 225         /* otherwise, opts.preserve_ignored is irrelevant */
 226         if (opts.merge && !opts.index_only)
 227                 setup_work_tree();
 228
 229         if (opts.skip_sparse_checkout)
 230                 ensure_full_index(&the_index);
 231
 232         if (opts.merge) {
 233                 switch (stage - 1) {
 234                 case 0:
 235                         die("you must specify at least one tree to merge");
 236                         break;
 237                 case 1:
 238                         opts.fn = opts.prefix ? bind_merge : oneway_merge;
 239                         break;
 240                 case 2:
 241                         opts.fn = twoway_merge;
 242                         opts.initial_checkout = is_index_unborn(&the_index);
 243                         break;
 244                 case 3:
 245                 default:
 246                         opts.fn = threeway_merge;
 247                         break;
 248                 }
 249
 250                 if (stage - 1 >= 3)
 251                         opts.head_idx = stage - 2;
 252                 else
 253                         opts.head_idx = 1;
 254         }
 255
 256         if (opts.internal.debug_unpack)
 257                 opts.fn = debug_merge;
 258
 259         /* If we're going to prime_cache_tree later, skip cache tree update */
 260         if (nr_trees == 1 && !opts.prefix)
 261                 opts.skip_cache_tree_update = 1;
 262
 263         cache_tree_free(&the_index.cache_tree);
 264         for (i = 0; i < nr_trees; i++) {
 265                 struct tree *tree = trees[i];
 266                 parse_tree(tree);
 267                 init_tree_desc(t+i, tree->buffer, tree->size);
 268         }
 269         if (unpack_trees(nr_trees, t, &opts))
 270                 return 128;
 271
 272         if (opts.internal.debug_unpack || opts.dry_run)
 273                 return 0; /* do not write the index out */
 274
 275         /*
 276          * When reading only one tree (either the most basic form,
 277          * "-m ent" or "--reset ent" form), we can obtain a fully
 278          * valid cache-tree because the index must match exactly
 279          * what came from the tree.
 280          */
 281         if (nr_trees == 1 && !opts.prefix)
 282                 prime_cache_tree(the_repository,
 283                                  the_repository->index,
 284                                  trees[0]);
 285
 286         if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 287                 die("unable to write new index file");
 288         return 0;
 289 }