Andrew's git - gitweb.git/blob - 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
  22static int nr_trees;
  23static int read_empty;
  24static struct tree *trees[MAX_UNPACK_TREES];
  25
  26static 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
  39static 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
  44static 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
  51static 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
  73static 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
  87static 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
 102static 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
 110static struct lock_file lock_file;
 111
 112int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
 113{
 114        int i, stage = 0;
 115        struct object_id oid;
 116        struct tree_desc t[MAX_UNPACK_TREES];
 117        struct unpack_trees_options opts;
 118        int prefix_set = 0;
 119        const struct option read_tree_options[] = {
 120                { OPTION_CALLBACK, 0, "index-output", NULL, N_("file"),
 121                  N_("write resulting index to <file>"),
 122                  PARSE_OPT_NONEG, index_output_cb },
 123                OPT_BOOL(0, "empty", &read_empty,
 124                            N_("only empty the index")),
 125                OPT__VERBOSE(&opts.verbose_update, N_("be verbose")),
 126                OPT_GROUP(N_("Merging")),
 127                OPT_BOOL('m', NULL, &opts.merge,
 128                         N_("perform a merge in addition to a read")),
 129                OPT_BOOL(0, "trivial", &opts.trivial_merges_only,
 130                         N_("3-way merge if no file level merging required")),
 131                OPT_BOOL(0, "aggressive", &opts.aggressive,
 132                         N_("3-way merge in presence of adds and removes")),
 133                OPT_BOOL(0, "reset", &opts.reset,
 134                         N_("same as -m, but discard unmerged entries")),
 135                { OPTION_STRING, 0, "prefix", &opts.prefix, N_("<subdirectory>/"),
 136                  N_("read the tree into the index under <subdirectory>/"),
 137                  PARSE_OPT_NONEG | PARSE_OPT_LITERAL_ARGHELP },
 138                OPT_BOOL('u', NULL, &opts.update,
 139                         N_("update working tree with merge result")),
 140                { OPTION_CALLBACK, 0, "exclude-per-directory", &opts,
 141                  N_("gitignore"),
 142                  N_("allow explicitly ignored files to be overwritten"),
 143                  PARSE_OPT_NONEG, exclude_per_directory_cb },
 144                OPT_BOOL('i', NULL, &opts.index_only,
 145                         N_("don't check the working tree after merging")),
 146                OPT__DRY_RUN(&opts.dry_run, N_("don't update the index or the work tree")),
 147                OPT_BOOL(0, "no-sparse-checkout", &opts.skip_sparse_checkout,
 148                         N_("skip applying sparse checkout filter")),
 149                OPT_BOOL(0, "debug-unpack", &opts.debug_unpack,
 150                         N_("debug unpack-trees")),
 151                { OPTION_CALLBACK, 0, "recurse-submodules", NULL,
 152                            "checkout", "control recursive updating of submodules",
 153                            PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater },
 154                OPT_END()
 155        };
 156
 157        memset(&opts, 0, sizeof(opts));
 158        opts.head_idx = -1;
 159        opts.src_index = &the_index;
 160        opts.dst_index = &the_index;
 161
 162        git_config(git_read_tree_config, NULL);
 163
 164        argc = parse_options(argc, argv, unused_prefix, read_tree_options,
 165                             read_tree_usage, 0);
 166
 167        hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
 168
 169        prefix_set = opts.prefix ? 1 : 0;
 170        if (1 < opts.merge + opts.reset + prefix_set)
 171                die("Which one? -m, --reset, or --prefix?");
 172
 173        /*
 174         * NEEDSWORK
 175         *
 176         * The old index should be read anyway even if we're going to
 177         * destroy all index entries because we still need to preserve
 178         * certain information such as index version or split-index
 179         * mode.
 180         */
 181
 182        if (opts.reset || opts.merge || opts.prefix) {
 183                if (read_cache_unmerged() && (opts.prefix || opts.merge))
 184                        die("You need to resolve your current index first");
 185                stage = opts.merge = 1;
 186        }
 187        resolve_undo_clear();
 188
 189        for (i = 0; i < argc; i++) {
 190                const char *arg = argv[i];
 191
 192                if (get_oid(arg, &oid))
 193                        die("Not a valid object name %s", arg);
 194                if (list_tree(&oid) < 0)
 195                        die("failed to unpack tree object %s", arg);
 196                stage++;
 197        }
 198        if (!nr_trees && !read_empty && !opts.merge)
 199                warning("read-tree: emptying the index with no arguments is deprecated; use --empty");
 200        else if (nr_trees > 0 && read_empty)
 201                die("passing trees as arguments contradicts --empty");
 202
 203        if (1 < opts.index_only + opts.update)
 204                die("-u and -i at the same time makes no sense");
 205        if ((opts.update || opts.index_only) && !opts.merge)
 206                die("%s is meaningless without -m, --reset, or --prefix",
 207                    opts.update ? "-u" : "-i");
 208        if ((opts.dir && !opts.update))
 209                die("--exclude-per-directory is meaningless unless -u");
 210        if (opts.merge && !opts.index_only)
 211                setup_work_tree();
 212
 213        if (opts.merge) {
 214                switch (stage - 1) {
 215                case 0:
 216                        die("you must specify at least one tree to merge");
 217                        break;
 218                case 1:
 219                        opts.fn = opts.prefix ? bind_merge : oneway_merge;
 220                        break;
 221                case 2:
 222                        opts.fn = twoway_merge;
 223                        opts.initial_checkout = is_cache_unborn();
 224                        break;
 225                case 3:
 226                default:
 227                        opts.fn = threeway_merge;
 228                        break;
 229                }
 230
 231                if (stage - 1 >= 3)
 232                        opts.head_idx = stage - 2;
 233                else
 234                        opts.head_idx = 1;
 235        }
 236
 237        if (opts.debug_unpack)
 238                opts.fn = debug_merge;
 239
 240        cache_tree_free(&active_cache_tree);
 241        for (i = 0; i < nr_trees; i++) {
 242                struct tree *tree = trees[i];
 243                parse_tree(tree);
 244                init_tree_desc(t+i, tree->buffer, tree->size);
 245        }
 246        if (unpack_trees(nr_trees, t, &opts))
 247                return 128;
 248
 249        if (opts.debug_unpack || opts.dry_run)
 250                return 0; /* do not write the index out */
 251
 252        /*
 253         * When reading only one tree (either the most basic form,
 254         * "-m ent" or "--reset ent" form), we can obtain a fully
 255         * valid cache-tree because the index must match exactly
 256         * what came from the tree.
 257         */
 258        if (nr_trees == 1 && !opts.prefix)
 259                prime_cache_tree(&the_index, trees[0]);
 260
 261        if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 262                die("unable to write new index file");
 263        return 0;
 264}