builtin/read-tree.c

   1 /*
   2  * GIT - The information manager from hell
   3  *
   4  * Copyright (C) Linus Torvalds, 2005
   5  */
   6
   7 #include "cache.h"
   8 #include "lockfile.h"
   9 #include "object.h"
  10 #include "tree.h"
  11 #include "tree-walk.h"
  12 #include "cache-tree.h"
  13 #include "unpack-trees.h"
  14 #include "dir.h"
  15 #include "builtin.h"
  16 #include "parse-options.h"
  17 #include "resolve-undo.h"
  18 #include "submodule.h"
  19 #include "submodule-config.h"
  20
  21 static int nr_trees;
  22 static int read_empty;
  23 static struct tree *trees[MAX_UNPACK_TREES];
  24
  25 static int list_tree(struct object_id *oid)
  26 {
  27         struct tree *tree;
  28
  29         if (nr_trees >= MAX_UNPACK_TREES)
  30                 die("I cannot read more than %d trees", MAX_UNPACK_TREES);
  31         tree = parse_tree_indirect(oid);
  32         if (!tree)
  33                 return -1;
  34         trees[nr_trees++] = tree;
  35         return 0;
  36 }
  37
  38 static const char * const read_tree_usage[] = {
  39         N_("git read-tree [(-m [--trivial] [--aggressive] | --reset | --prefix=<prefix>) [-u [--exclude-per-directory=<gitignore>] | -i]] [--no-sparse-checkout] [--index-output=<file>] (--empty | <tree-ish1> [<tree-ish2> [<tree-ish3>]])"),
  40         NULL
  41 };
  42
  43 static int index_output_cb(const struct option *opt, const char *arg,
  44                                  int unset)
  45 {
  46         set_alternate_index_output(arg);
  47         return 0;
  48 }
  49
  50 static int exclude_per_directory_cb(const struct option *opt, const char *arg,
  51                                     int unset)
  52 {
  53         struct dir_struct *dir;
  54         struct unpack_trees_options *opts;
  55
  56         opts = (struct unpack_trees_options *)opt->value;
  57
  58         if (opts->dir)
  59                 die("more than one --exclude-per-directory given.");
  60
  61         dir = xcalloc(1, sizeof(*opts->dir));
  62         dir->flags |= DIR_SHOW_IGNORED;
  63         dir->exclude_per_dir = arg;
  64         opts->dir = dir;
  65         /* We do not need to nor want to do read-directory
  66          * here; we are merely interested in reusing the
  67          * per directory ignore stack mechanism.
  68          */
  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 static struct lock_file lock_file;
 110
 111 int cmd_read_tree(int argc, const char **argv, const char *unused_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         const struct option read_tree_options[] = {
 119                 { OPTION_CALLBACK, 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 | PARSE_OPT_LITERAL_ARGHELP },
 137                 OPT_BOOL('u', NULL, &opts.update,
 138                          N_("update working tree with merge result")),
 139                 { OPTION_CALLBACK, 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                 { OPTION_CALLBACK, 0, "recurse-submodules", NULL,
 151                             "checkout", "control recursive updating of submodules",
 152                             PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater },
 153                 OPT_END()
 154         };
 155
 156         memset(&opts, 0, sizeof(opts));
 157         opts.head_idx = -1;
 158         opts.src_index = &the_index;
 159         opts.dst_index = &the_index;
 160
 161         git_config(git_read_tree_config, NULL);
 162
 163         argc = parse_options(argc, argv, unused_prefix, read_tree_options,
 164                              read_tree_usage, 0);
 165
 166         load_submodule_cache();
 167
 168         hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
 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         /*
 175          * NEEDSWORK
 176          *
 177          * The old index should be read anyway even if we're going to
 178          * destroy all index entries because we still need to preserve
 179          * certain information such as index version or split-index
 180          * mode.
 181          */
 182
 183         if (opts.reset || opts.merge || opts.prefix) {
 184                 if (read_cache_unmerged() && (opts.prefix || opts.merge))
 185                         die("You need to resolve your current index first");
 186                 stage = opts.merge = 1;
 187         }
 188         resolve_undo_clear();
 189
 190         for (i = 0; i < argc; i++) {
 191                 const char *arg = argv[i];
 192
 193                 if (get_oid(arg, &oid))
 194                         die("Not a valid object name %s", arg);
 195                 if (list_tree(&oid) < 0)
 196                         die("failed to unpack tree object %s", arg);
 197                 stage++;
 198         }
 199         if (!nr_trees && !read_empty && !opts.merge)
 200                 warning("read-tree: emptying the index with no arguments is deprecated; use --empty");
 201         else if (nr_trees > 0 && read_empty)
 202                 die("passing trees as arguments contradicts --empty");
 203
 204         if (1 < opts.index_only + opts.update)
 205                 die("-u and -i at the same time makes no sense");
 206         if ((opts.update || opts.index_only) && !opts.merge)
 207                 die("%s is meaningless without -m, --reset, or --prefix",
 208                     opts.update ? "-u" : "-i");
 209         if ((opts.dir && !opts.update))
 210                 die("--exclude-per-directory is meaningless unless -u");
 211         if (opts.merge && !opts.index_only)
 212                 setup_work_tree();
 213
 214         if (opts.merge) {
 215                 switch (stage - 1) {
 216                 case 0:
 217                         die("you must specify at least one tree to merge");
 218                         break;
 219                 case 1:
 220                         opts.fn = opts.prefix ? bind_merge : oneway_merge;
 221                         break;
 222                 case 2:
 223                         opts.fn = twoway_merge;
 224                         opts.initial_checkout = is_cache_unborn();
 225                         break;
 226                 case 3:
 227                 default:
 228                         opts.fn = threeway_merge;
 229                         break;
 230                 }
 231
 232                 if (stage - 1 >= 3)
 233                         opts.head_idx = stage - 2;
 234                 else
 235                         opts.head_idx = 1;
 236         }
 237
 238         if (opts.debug_unpack)
 239                 opts.fn = debug_merge;
 240
 241         cache_tree_free(&active_cache_tree);
 242         for (i = 0; i < nr_trees; i++) {
 243                 struct tree *tree = trees[i];
 244                 parse_tree(tree);
 245                 init_tree_desc(t+i, tree->buffer, tree->size);
 246         }
 247         if (unpack_trees(nr_trees, t, &opts))
 248                 return 128;
 249
 250         if (opts.debug_unpack || opts.dry_run)
 251                 return 0; /* do not write the index out */
 252
 253         /*
 254          * When reading only one tree (either the most basic form,
 255          * "-m ent" or "--reset ent" form), we can obtain a fully
 256          * valid cache-tree because the index must match exactly
 257          * what came from the tree.
 258          */
 259         if (nr_trees == 1 && !opts.prefix)
 260                 prime_cache_tree(&the_index, trees[0]);
 261
 262         if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 263                 die("unable to write new index file");
 264         return 0;
 265 }