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