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
  19 static int nr_trees;
  20 static int read_empty;
  21 static struct tree *trees[MAX_UNPACK_TREES];
  22
  23 static int list_tree(unsigned char *sha1)
  24 {
  25         struct tree *tree;
  26
  27         if (nr_trees >= MAX_UNPACK_TREES)
  28                 die("I cannot read more than %d trees", MAX_UNPACK_TREES);
  29         tree = parse_tree_indirect(sha1);
  30         if (!tree)
  31                 return -1;
  32         trees[nr_trees++] = tree;
  33         return 0;
  34 }
  35
  36 static const char * const read_tree_usage[] = {
  37         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>]])"),
  38         NULL
  39 };
  40
  41 static int index_output_cb(const struct option *opt, const char *arg,
  42                                  int unset)
  43 {
  44         set_alternate_index_output(arg);
  45         return 0;
  46 }
  47
  48 static int exclude_per_directory_cb(const struct option *opt, const char *arg,
  49                                     int unset)
  50 {
  51         struct dir_struct *dir;
  52         struct unpack_trees_options *opts;
  53
  54         opts = (struct unpack_trees_options *)opt->value;
  55
  56         if (opts->dir)
  57                 die("more than one --exclude-per-directory given.");
  58
  59         dir = xcalloc(1, sizeof(*opts->dir));
  60         dir->flags |= DIR_SHOW_IGNORED;
  61         dir->exclude_per_dir = arg;
  62         opts->dir = dir;
  63         /* We do not need to nor want to do read-directory
  64          * here; we are merely interested in reusing the
  65          * per directory ignore stack mechanism.
  66          */
  67         return 0;
  68 }
  69
  70 static void debug_stage(const char *label, const struct cache_entry *ce,
  71                         struct unpack_trees_options *o)
  72 {
  73         printf("%s ", label);
  74         if (!ce)
  75                 printf("(missing)\n");
  76         else if (ce == o->df_conflict_entry)
  77                 printf("(conflict)\n");
  78         else
  79                 printf("%06o #%d %s %.8s\n",
  80                        ce->ce_mode, ce_stage(ce), ce->name,
  81                        oid_to_hex(&ce->oid));
  82 }
  83
  84 static int debug_merge(const struct cache_entry * const *stages,
  85                        struct unpack_trees_options *o)
  86 {
  87         int i;
  88
  89         printf("* %d-way merge\n", o->merge_size);
  90         debug_stage("index", stages[0], o);
  91         for (i = 1; i <= o->merge_size; i++) {
  92                 char buf[24];
  93                 xsnprintf(buf, sizeof(buf), "ent#%d", i);
  94                 debug_stage(buf, stages[i], o);
  95         }
  96         return 0;
  97 }
  98
  99 static struct lock_file lock_file;
 100
 101 int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
 102 {
 103         int i, stage = 0;
 104         unsigned char sha1[20];
 105         struct tree_desc t[MAX_UNPACK_TREES];
 106         struct unpack_trees_options opts;
 107         int prefix_set = 0;
 108         const struct option read_tree_options[] = {
 109                 { OPTION_CALLBACK, 0, "index-output", NULL, N_("file"),
 110                   N_("write resulting index to <file>"),
 111                   PARSE_OPT_NONEG, index_output_cb },
 112                 OPT_SET_INT(0, "empty", &read_empty,
 113                             N_("only empty the index"), 1),
 114                 OPT__VERBOSE(&opts.verbose_update, N_("be verbose")),
 115                 OPT_GROUP(N_("Merging")),
 116                 OPT_SET_INT('m', NULL, &opts.merge,
 117                             N_("perform a merge in addition to a read"), 1),
 118                 OPT_SET_INT(0, "trivial", &opts.trivial_merges_only,
 119                             N_("3-way merge if no file level merging required"), 1),
 120                 OPT_SET_INT(0, "aggressive", &opts.aggressive,
 121                             N_("3-way merge in presence of adds and removes"), 1),
 122                 OPT_SET_INT(0, "reset", &opts.reset,
 123                             N_("same as -m, but discard unmerged entries"), 1),
 124                 { OPTION_STRING, 0, "prefix", &opts.prefix, N_("<subdirectory>/"),
 125                   N_("read the tree into the index under <subdirectory>/"),
 126                   PARSE_OPT_NONEG | PARSE_OPT_LITERAL_ARGHELP },
 127                 OPT_SET_INT('u', NULL, &opts.update,
 128                             N_("update working tree with merge result"), 1),
 129                 { OPTION_CALLBACK, 0, "exclude-per-directory", &opts,
 130                   N_("gitignore"),
 131                   N_("allow explicitly ignored files to be overwritten"),
 132                   PARSE_OPT_NONEG, exclude_per_directory_cb },
 133                 OPT_SET_INT('i', NULL, &opts.index_only,
 134                             N_("don't check the working tree after merging"), 1),
 135                 OPT__DRY_RUN(&opts.dry_run, N_("don't update the index or the work tree")),
 136                 OPT_SET_INT(0, "no-sparse-checkout", &opts.skip_sparse_checkout,
 137                             N_("skip applying sparse checkout filter"), 1),
 138                 OPT_SET_INT(0, "debug-unpack", &opts.debug_unpack,
 139                             N_("debug unpack-trees"), 1),
 140                 OPT_END()
 141         };
 142
 143         memset(&opts, 0, sizeof(opts));
 144         opts.head_idx = -1;
 145         opts.src_index = &the_index;
 146         opts.dst_index = &the_index;
 147
 148         git_config(git_default_config, NULL);
 149
 150         argc = parse_options(argc, argv, unused_prefix, read_tree_options,
 151                              read_tree_usage, 0);
 152
 153         hold_locked_index(&lock_file, 1);
 154
 155         prefix_set = opts.prefix ? 1 : 0;
 156         if (1 < opts.merge + opts.reset + prefix_set)
 157                 die("Which one? -m, --reset, or --prefix?");
 158
 159         /*
 160          * NEEDSWORK
 161          *
 162          * The old index should be read anyway even if we're going to
 163          * destroy all index entries because we still need to preserve
 164          * certain information such as index version or split-index
 165          * mode.
 166          */
 167
 168         if (opts.reset || opts.merge || opts.prefix) {
 169                 if (read_cache_unmerged() && (opts.prefix || opts.merge))
 170                         die("You need to resolve your current index first");
 171                 stage = opts.merge = 1;
 172         }
 173         resolve_undo_clear();
 174
 175         for (i = 0; i < argc; i++) {
 176                 const char *arg = argv[i];
 177
 178                 if (get_sha1(arg, sha1))
 179                         die("Not a valid object name %s", arg);
 180                 if (list_tree(sha1) < 0)
 181                         die("failed to unpack tree object %s", arg);
 182                 stage++;
 183         }
 184         if (nr_trees == 0 && !read_empty)
 185                 warning("read-tree: emptying the index with no arguments is deprecated; use --empty");
 186         else if (nr_trees > 0 && read_empty)
 187                 die("passing trees as arguments contradicts --empty");
 188
 189         if (1 < opts.index_only + opts.update)
 190                 die("-u and -i at the same time makes no sense");
 191         if ((opts.update || opts.index_only) && !opts.merge)
 192                 die("%s is meaningless without -m, --reset, or --prefix",
 193                     opts.update ? "-u" : "-i");
 194         if ((opts.dir && !opts.update))
 195                 die("--exclude-per-directory is meaningless unless -u");
 196         if (opts.merge && !opts.index_only)
 197                 setup_work_tree();
 198
 199         if (opts.merge) {
 200                 if (stage < 2)
 201                         die("just how do you expect me to merge %d trees?", stage-1);
 202                 switch (stage - 1) {
 203                 case 1:
 204                         opts.fn = opts.prefix ? bind_merge : oneway_merge;
 205                         break;
 206                 case 2:
 207                         opts.fn = twoway_merge;
 208                         opts.initial_checkout = is_cache_unborn();
 209                         break;
 210                 case 3:
 211                 default:
 212                         opts.fn = threeway_merge;
 213                         break;
 214                 }
 215
 216                 if (stage - 1 >= 3)
 217                         opts.head_idx = stage - 2;
 218                 else
 219                         opts.head_idx = 1;
 220         }
 221
 222         if (opts.debug_unpack)
 223                 opts.fn = debug_merge;
 224
 225         cache_tree_free(&active_cache_tree);
 226         for (i = 0; i < nr_trees; i++) {
 227                 struct tree *tree = trees[i];
 228                 parse_tree(tree);
 229                 init_tree_desc(t+i, tree->buffer, tree->size);
 230         }
 231         if (unpack_trees(nr_trees, t, &opts))
 232                 return 128;
 233
 234         if (opts.debug_unpack || opts.dry_run)
 235                 return 0; /* do not write the index out */
 236
 237         /*
 238          * When reading only one tree (either the most basic form,
 239          * "-m ent" or "--reset ent" form), we can obtain a fully
 240          * valid cache-tree because the index must match exactly
 241          * what came from the tree.
 242          */
 243         if (nr_trees == 1 && !opts.prefix)
 244                 prime_cache_tree(&the_index, trees[0]);
 245
 246         if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 247                 die("unable to write new index file");
 248         return 0;
 249 }