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 static int recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
  25
  26 static int list_tree(unsigned char *sha1)
  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(sha1);
  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 option_parse_recurse_submodules(const struct option *opt,
 103                                            const char *arg, int unset)
 104 {
 105         if (unset) {
 106                 recurse_submodules = RECURSE_SUBMODULES_OFF;
 107                 return 0;
 108         }
 109         if (arg)
 110                 recurse_submodules =
 111                         parse_update_recurse_submodules_arg(opt->long_name,
 112                                                             arg);
 113         else
 114                 recurse_submodules = RECURSE_SUBMODULES_ON;
 115
 116         return 0;
 117 }
 118
 119 static struct lock_file lock_file;
 120
 121 int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
 122 {
 123         int i, stage = 0;
 124         unsigned char sha1[20];
 125         struct tree_desc t[MAX_UNPACK_TREES];
 126         struct unpack_trees_options opts;
 127         int prefix_set = 0;
 128         const struct option read_tree_options[] = {
 129                 { OPTION_CALLBACK, 0, "index-output", NULL, N_("file"),
 130                   N_("write resulting index to <file>"),
 131                   PARSE_OPT_NONEG, index_output_cb },
 132                 OPT_BOOL(0, "empty", &read_empty,
 133                             N_("only empty the index")),
 134                 OPT__VERBOSE(&opts.verbose_update, N_("be verbose")),
 135                 OPT_GROUP(N_("Merging")),
 136                 OPT_BOOL('m', NULL, &opts.merge,
 137                          N_("perform a merge in addition to a read")),
 138                 OPT_BOOL(0, "trivial", &opts.trivial_merges_only,
 139                          N_("3-way merge if no file level merging required")),
 140                 OPT_BOOL(0, "aggressive", &opts.aggressive,
 141                          N_("3-way merge in presence of adds and removes")),
 142                 OPT_BOOL(0, "reset", &opts.reset,
 143                          N_("same as -m, but discard unmerged entries")),
 144                 { OPTION_STRING, 0, "prefix", &opts.prefix, N_("<subdirectory>/"),
 145                   N_("read the tree into the index under <subdirectory>/"),
 146                   PARSE_OPT_NONEG | PARSE_OPT_LITERAL_ARGHELP },
 147                 OPT_BOOL('u', NULL, &opts.update,
 148                          N_("update working tree with merge result")),
 149                 { OPTION_CALLBACK, 0, "exclude-per-directory", &opts,
 150                   N_("gitignore"),
 151                   N_("allow explicitly ignored files to be overwritten"),
 152                   PARSE_OPT_NONEG, exclude_per_directory_cb },
 153                 OPT_BOOL('i', NULL, &opts.index_only,
 154                          N_("don't check the working tree after merging")),
 155                 OPT__DRY_RUN(&opts.dry_run, N_("don't update the index or the work tree")),
 156                 OPT_BOOL(0, "no-sparse-checkout", &opts.skip_sparse_checkout,
 157                          N_("skip applying sparse checkout filter")),
 158                 OPT_BOOL(0, "debug-unpack", &opts.debug_unpack,
 159                          N_("debug unpack-trees")),
 160                 { OPTION_CALLBACK, 0, "recurse-submodules", &recurse_submodules,
 161                             "checkout", "control recursive updating of submodules",
 162                             PARSE_OPT_OPTARG, option_parse_recurse_submodules },
 163                 OPT_END()
 164         };
 165
 166         memset(&opts, 0, sizeof(opts));
 167         opts.head_idx = -1;
 168         opts.src_index = &the_index;
 169         opts.dst_index = &the_index;
 170
 171         git_config(git_default_config, NULL);
 172
 173         argc = parse_options(argc, argv, unused_prefix, read_tree_options,
 174                              read_tree_usage, 0);
 175
 176         hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
 177
 178         if (recurse_submodules != RECURSE_SUBMODULES_DEFAULT) {
 179                 gitmodules_config();
 180                 git_config(submodule_config, NULL);
 181                 set_config_update_recurse_submodules(RECURSE_SUBMODULES_ON);
 182         }
 183
 184         prefix_set = opts.prefix ? 1 : 0;
 185         if (1 < opts.merge + opts.reset + prefix_set)
 186                 die("Which one? -m, --reset, or --prefix?");
 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 (read_cache_unmerged() && (opts.prefix || opts.merge))
 199                         die("You need to resolve your current index first");
 200                 stage = opts.merge = 1;
 201         }
 202         resolve_undo_clear();
 203
 204         for (i = 0; i < argc; i++) {
 205                 const char *arg = argv[i];
 206
 207                 if (get_sha1(arg, sha1))
 208                         die("Not a valid object name %s", arg);
 209                 if (list_tree(sha1) < 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.dir && !opts.update))
 224                 die("--exclude-per-directory is meaningless unless -u");
 225         if (opts.merge && !opts.index_only)
 226                 setup_work_tree();
 227
 228         if (opts.merge) {
 229                 switch (stage - 1) {
 230                 case 0:
 231                         die("you must specify at least one tree to merge");
 232                         break;
 233                 case 1:
 234                         opts.fn = opts.prefix ? bind_merge : oneway_merge;
 235                         break;
 236                 case 2:
 237                         opts.fn = twoway_merge;
 238                         opts.initial_checkout = is_cache_unborn();
 239                         break;
 240                 case 3:
 241                 default:
 242                         opts.fn = threeway_merge;
 243                         break;
 244                 }
 245
 246                 if (stage - 1 >= 3)
 247                         opts.head_idx = stage - 2;
 248                 else
 249                         opts.head_idx = 1;
 250         }
 251
 252         if (opts.debug_unpack)
 253                 opts.fn = debug_merge;
 254
 255         cache_tree_free(&active_cache_tree);
 256         for (i = 0; i < nr_trees; i++) {
 257                 struct tree *tree = trees[i];
 258                 parse_tree(tree);
 259                 init_tree_desc(t+i, tree->buffer, tree->size);
 260         }
 261         if (unpack_trees(nr_trees, t, &opts))
 262                 return 128;
 263
 264         if (opts.debug_unpack || opts.dry_run)
 265                 return 0; /* do not write the index out */
 266
 267         /*
 268          * When reading only one tree (either the most basic form,
 269          * "-m ent" or "--reset ent" form), we can obtain a fully
 270          * valid cache-tree because the index must match exactly
 271          * what came from the tree.
 272          */
 273         if (nr_trees == 1 && !opts.prefix)
 274                 prime_cache_tree(&the_index, trees[0]);
 275
 276         if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 277                 die("unable to write new index file");
 278         return 0;
 279 }