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 "object.h"
   9 #include "tree.h"
  10 #include "tree-walk.h"
  11 #include "cache-tree.h"
  12 #include "unpack-trees.h"
  13 #include "dir.h"
  14 #include "builtin.h"
  15 #include "parse-options.h"
  16 #include "resolve-undo.h"
  17
  18 static int nr_trees;
  19 static int read_empty;
  20 static struct tree *trees[MAX_UNPACK_TREES];
  21
  22 static int list_tree(unsigned char *sha1)
  23 {
  24         struct tree *tree;
  25
  26         if (nr_trees >= MAX_UNPACK_TREES)
  27                 die("I cannot read more than %d trees", MAX_UNPACK_TREES);
  28         tree = parse_tree_indirect(sha1);
  29         if (!tree)
  30                 return -1;
  31         trees[nr_trees++] = tree;
  32         return 0;
  33 }
  34
  35 static const char * const read_tree_usage[] = {
  36         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>]])"),
  37         NULL
  38 };
  39
  40 static int index_output_cb(const struct option *opt, const char *arg,
  41                                  int unset)
  42 {
  43         set_alternate_index_output(arg);
  44         return 0;
  45 }
  46
  47 static int exclude_per_directory_cb(const struct option *opt, const char *arg,
  48                                     int unset)
  49 {
  50         struct dir_struct *dir;
  51         struct unpack_trees_options *opts;
  52
  53         opts = (struct unpack_trees_options *)opt->value;
  54
  55         if (opts->dir)
  56                 die("more than one --exclude-per-directory given.");
  57
  58         dir = xcalloc(1, sizeof(*opts->dir));
  59         dir->flags |= DIR_SHOW_IGNORED;
  60         dir->exclude_per_dir = arg;
  61         opts->dir = dir;
  62         /* We do not need to nor want to do read-directory
  63          * here; we are merely interested in reusing the
  64          * per directory ignore stack mechanism.
  65          */
  66         return 0;
  67 }
  68
  69 static void debug_stage(const char *label, const struct cache_entry *ce,
  70                         struct unpack_trees_options *o)
  71 {
  72         printf("%s ", label);
  73         if (!ce)
  74                 printf("(missing)\n");
  75         else if (ce == o->df_conflict_entry)
  76                 printf("(conflict)\n");
  77         else
  78                 printf("%06o #%d %s %.8s\n",
  79                        ce->ce_mode, ce_stage(ce), ce->name,
  80                        sha1_to_hex(ce->sha1));
  81 }
  82
  83 static int debug_merge(const struct cache_entry * const *stages,
  84                        struct unpack_trees_options *o)
  85 {
  86         int i;
  87
  88         printf("* %d-way merge\n", o->merge_size);
  89         debug_stage("index", stages[0], o);
  90         for (i = 1; i <= o->merge_size; i++) {
  91                 char buf[24];
  92                 sprintf(buf, "ent#%d", i);
  93                 debug_stage(buf, stages[i], o);
  94         }
  95         return 0;
  96 }
  97
  98 static struct lock_file lock_file;
  99
 100 int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
 101 {
 102         int i, stage = 0;
 103         unsigned char sha1[20];
 104         struct tree_desc t[MAX_UNPACK_TREES];
 105         struct unpack_trees_options opts;
 106         int prefix_set = 0;
 107         const struct option read_tree_options[] = {
 108                 { OPTION_CALLBACK, 0, "index-output", NULL, N_("file"),
 109                   N_("write resulting index to <file>"),
 110                   PARSE_OPT_NONEG, index_output_cb },
 111                 OPT_SET_INT(0, "empty", &read_empty,
 112                             N_("only empty the index"), 1),
 113                 OPT__VERBOSE(&opts.verbose_update, N_("be verbose")),
 114                 OPT_GROUP(N_("Merging")),
 115                 OPT_SET_INT('m', NULL, &opts.merge,
 116                             N_("perform a merge in addition to a read"), 1),
 117                 OPT_SET_INT(0, "trivial", &opts.trivial_merges_only,
 118                             N_("3-way merge if no file level merging required"), 1),
 119                 OPT_SET_INT(0, "aggressive", &opts.aggressive,
 120                             N_("3-way merge in presence of adds and removes"), 1),
 121                 OPT_SET_INT(0, "reset", &opts.reset,
 122                             N_("same as -m, but discard unmerged entries"), 1),
 123                 { OPTION_STRING, 0, "prefix", &opts.prefix, N_("<subdirectory>/"),
 124                   N_("read the tree into the index under <subdirectory>/"),
 125                   PARSE_OPT_NONEG | PARSE_OPT_LITERAL_ARGHELP },
 126                 OPT_SET_INT('u', NULL, &opts.update,
 127                             N_("update working tree with merge result"), 1),
 128                 { OPTION_CALLBACK, 0, "exclude-per-directory", &opts,
 129                   N_("gitignore"),
 130                   N_("allow explicitly ignored files to be overwritten"),
 131                   PARSE_OPT_NONEG, exclude_per_directory_cb },
 132                 OPT_SET_INT('i', NULL, &opts.index_only,
 133                             N_("don't check the working tree after merging"), 1),
 134                 OPT__DRY_RUN(&opts.dry_run, N_("don't update the index or the work tree")),
 135                 OPT_SET_INT(0, "no-sparse-checkout", &opts.skip_sparse_checkout,
 136                             N_("skip applying sparse checkout filter"), 1),
 137                 OPT_SET_INT(0, "debug-unpack", &opts.debug_unpack,
 138                             N_("debug unpack-trees"), 1),
 139                 OPT_END()
 140         };
 141
 142         memset(&opts, 0, sizeof(opts));
 143         opts.head_idx = -1;
 144         opts.src_index = &the_index;
 145         opts.dst_index = &the_index;
 146
 147         git_config(git_default_config, NULL);
 148
 149         argc = parse_options(argc, argv, unused_prefix, read_tree_options,
 150                              read_tree_usage, 0);
 151
 152         hold_locked_index(&lock_file, 1);
 153
 154         prefix_set = opts.prefix ? 1 : 0;
 155         if (1 < opts.merge + opts.reset + prefix_set)
 156                 die("Which one? -m, --reset, or --prefix?");
 157
 158         /*
 159          * NEEDSWORK
 160          *
 161          * The old index should be read anyway even if we're going to
 162          * destroy all index entries because we still need to preserve
 163          * certain information such as index version or split-index
 164          * mode.
 165          */
 166
 167         if (opts.reset || opts.merge || opts.prefix) {
 168                 if (read_cache_unmerged() && (opts.prefix || opts.merge))
 169                         die("You need to resolve your current index first");
 170                 stage = opts.merge = 1;
 171         }
 172         resolve_undo_clear();
 173
 174         for (i = 0; i < argc; i++) {
 175                 const char *arg = argv[i];
 176
 177                 if (get_sha1(arg, sha1))
 178                         die("Not a valid object name %s", arg);
 179                 if (list_tree(sha1) < 0)
 180                         die("failed to unpack tree object %s", arg);
 181                 stage++;
 182         }
 183         if (nr_trees == 0 && !read_empty)
 184                 warning("read-tree: emptying the index with no arguments is deprecated; use --empty");
 185         else if (nr_trees > 0 && read_empty)
 186                 die("passing trees as arguments contradicts --empty");
 187
 188         if (1 < opts.index_only + opts.update)
 189                 die("-u and -i at the same time makes no sense");
 190         if ((opts.update || opts.index_only) && !opts.merge)
 191                 die("%s is meaningless without -m, --reset, or --prefix",
 192                     opts.update ? "-u" : "-i");
 193         if ((opts.dir && !opts.update))
 194                 die("--exclude-per-directory is meaningless unless -u");
 195         if (opts.merge && !opts.index_only)
 196                 setup_work_tree();
 197
 198         if (opts.merge) {
 199                 if (stage < 2)
 200                         die("just how do you expect me to merge %d trees?", stage-1);
 201                 switch (stage - 1) {
 202                 case 1:
 203                         opts.fn = opts.prefix ? bind_merge : oneway_merge;
 204                         break;
 205                 case 2:
 206                         opts.fn = twoway_merge;
 207                         opts.initial_checkout = is_cache_unborn();
 208                         break;
 209                 case 3:
 210                 default:
 211                         opts.fn = threeway_merge;
 212                         break;
 213                 }
 214
 215                 if (stage - 1 >= 3)
 216                         opts.head_idx = stage - 2;
 217                 else
 218                         opts.head_idx = 1;
 219         }
 220
 221         if (opts.debug_unpack)
 222                 opts.fn = debug_merge;
 223
 224         cache_tree_free(&active_cache_tree);
 225         for (i = 0; i < nr_trees; i++) {
 226                 struct tree *tree = trees[i];
 227                 parse_tree(tree);
 228                 init_tree_desc(t+i, tree->buffer, tree->size);
 229         }
 230         if (unpack_trees(nr_trees, t, &opts))
 231                 return 128;
 232
 233         if (opts.debug_unpack || opts.dry_run)
 234                 return 0; /* do not write the index out */
 235
 236         /*
 237          * When reading only one tree (either the most basic form,
 238          * "-m ent" or "--reset ent" form), we can obtain a fully
 239          * valid cache-tree because the index must match exactly
 240          * what came from the tree.
 241          */
 242         if (nr_trees == 1 && !opts.prefix)
 243                 prime_cache_tree(&the_index, trees[0]);
 244
 245         if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 246                 die("unable to write new index file");
 247         return 0;
 248 }