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