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 "config.h"
   9 #include "lockfile.h"
  10 #include "object.h"
  11 #include "tree.h"
  12 #include "tree-walk.h"
  13 #include "cache-tree.h"
  14 #include "unpack-trees.h"
  15 #include "dir.h"
  16 #include "builtin.h"
  17 #include "parse-options.h"
  18 #include "resolve-undo.h"
  19 #include "submodule.h"
  20 #include "submodule-config.h"
  21
  22 static int nr_trees;
  23 static int read_empty;
  24 static struct tree *trees[MAX_UNPACK_TREES];
  25
  26 static int list_tree(struct object_id *oid)
  27 {
  28         struct tree *tree;
  29
  30         if (nr_trees >= MAX_UNPACK_TREES)
  31                 die("I cannot read more than %d trees", MAX_UNPACK_TREES);
  32         tree = parse_tree_indirect(oid);
  33         if (!tree)
  34                 return -1;
  35         trees[nr_trees++] = tree;
  36         return 0;
  37 }
  38
  39 static const char * const read_tree_usage[] = {
  40         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>]])"),
  41         NULL
  42 };
  43
  44 static int index_output_cb(const struct option *opt, const char *arg,
  45                                  int unset)
  46 {
  47         set_alternate_index_output(arg);
  48         return 0;
  49 }
  50
  51 static int exclude_per_directory_cb(const struct option *opt, const char *arg,
  52                                     int unset)
  53 {
  54         struct dir_struct *dir;
  55         struct unpack_trees_options *opts;
  56
  57         opts = (struct unpack_trees_options *)opt->value;
  58
  59         if (opts->dir)
  60                 die("more than one --exclude-per-directory given.");
  61
  62         dir = xcalloc(1, sizeof(*opts->dir));
  63         dir->flags |= DIR_SHOW_IGNORED;
  64         dir->exclude_per_dir = arg;
  65         opts->dir = dir;
  66         /* We do not need to nor want to do read-directory
  67          * here; we are merely interested in reusing the
  68          * per directory ignore stack mechanism.
  69          */
  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->merge_size);
  93         debug_stage("index", stages[0], o);
  94         for (i = 1; i <= o->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, void *cb)
 103 {
 104         if (!strcmp(var, "submodule.recurse"))
 105                 return git_default_submodule_config(var, value, cb);
 106
 107         return git_default_config(var, value, cb);
 108 }
 109
 110 int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
 111 {
 112         int i, stage = 0;
 113         struct object_id oid;
 114         struct tree_desc t[MAX_UNPACK_TREES];
 115         struct unpack_trees_options opts;
 116         int prefix_set = 0;
 117         struct lock_file lock_file = LOCK_INIT;
 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         hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
 167
 168         prefix_set = opts.prefix ? 1 : 0;
 169         if (1 < opts.merge + opts.reset + prefix_set)
 170                 die("Which one? -m, --reset, or --prefix?");
 171
 172         /*
 173          * NEEDSWORK
 174          *
 175          * The old index should be read anyway even if we're going to
 176          * destroy all index entries because we still need to preserve
 177          * certain information such as index version or split-index
 178          * mode.
 179          */
 180
 181         if (opts.reset || opts.merge || opts.prefix) {
 182                 if (read_cache_unmerged() && (opts.prefix || opts.merge))
 183                         die("You need to resolve your current index first");
 184                 stage = opts.merge = 1;
 185         }
 186         resolve_undo_clear();
 187
 188         for (i = 0; i < argc; i++) {
 189                 const char *arg = argv[i];
 190
 191                 if (get_oid(arg, &oid))
 192                         die("Not a valid object name %s", arg);
 193                 if (list_tree(&oid) < 0)
 194                         die("failed to unpack tree object %s", arg);
 195                 stage++;
 196         }
 197         if (!nr_trees && !read_empty && !opts.merge)
 198                 warning("read-tree: emptying the index with no arguments is deprecated; use --empty");
 199         else if (nr_trees > 0 && read_empty)
 200                 die("passing trees as arguments contradicts --empty");
 201
 202         if (1 < opts.index_only + opts.update)
 203                 die("-u and -i at the same time makes no sense");
 204         if ((opts.update || opts.index_only) && !opts.merge)
 205                 die("%s is meaningless without -m, --reset, or --prefix",
 206                     opts.update ? "-u" : "-i");
 207         if ((opts.dir && !opts.update))
 208                 die("--exclude-per-directory is meaningless unless -u");
 209         if (opts.merge && !opts.index_only)
 210                 setup_work_tree();
 211
 212         if (opts.merge) {
 213                 switch (stage - 1) {
 214                 case 0:
 215                         die("you must specify at least one tree to merge");
 216                         break;
 217                 case 1:
 218                         opts.fn = opts.prefix ? bind_merge : oneway_merge;
 219                         break;
 220                 case 2:
 221                         opts.fn = twoway_merge;
 222                         opts.initial_checkout = is_cache_unborn();
 223                         break;
 224                 case 3:
 225                 default:
 226                         opts.fn = threeway_merge;
 227                         break;
 228                 }
 229
 230                 if (stage - 1 >= 3)
 231                         opts.head_idx = stage - 2;
 232                 else
 233                         opts.head_idx = 1;
 234         }
 235
 236         if (opts.debug_unpack)
 237                 opts.fn = debug_merge;
 238
 239         cache_tree_free(&active_cache_tree);
 240         for (i = 0; i < nr_trees; i++) {
 241                 struct tree *tree = trees[i];
 242                 parse_tree(tree);
 243                 init_tree_desc(t+i, tree->buffer, tree->size);
 244         }
 245         if (unpack_trees(nr_trees, t, &opts))
 246                 return 128;
 247
 248         if (opts.debug_unpack || opts.dry_run)
 249                 return 0; /* do not write the index out */
 250
 251         /*
 252          * When reading only one tree (either the most basic form,
 253          * "-m ent" or "--reset ent" form), we can obtain a fully
 254          * valid cache-tree because the index must match exactly
 255          * what came from the tree.
 256          */
 257         if (nr_trees == 1 && !opts.prefix)
 258                 prime_cache_tree(&the_index, trees[0]);
 259
 260         if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 261                 die("unable to write new index file");
 262         return 0;
 263 }