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