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 "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
  21static int nr_trees;
  22static int read_empty;
  23static struct tree *trees[MAX_UNPACK_TREES];
  24static int recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
  25
  26static 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
  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 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
 119static struct lock_file lock_file;
 120
 121int 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 == 0 && !read_empty)
 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                if (stage < 2)
 230                        die("just how do you expect me to merge %d trees?", stage-1);
 231                switch (stage - 1) {
 232                case 1:
 233                        opts.fn = opts.prefix ? bind_merge : oneway_merge;
 234                        break;
 235                case 2:
 236                        opts.fn = twoway_merge;
 237                        opts.initial_checkout = is_cache_unborn();
 238                        break;
 239                case 3:
 240                default:
 241                        opts.fn = threeway_merge;
 242                        break;
 243                }
 244
 245                if (stage - 1 >= 3)
 246                        opts.head_idx = stage - 2;
 247                else
 248                        opts.head_idx = 1;
 249        }
 250
 251        if (opts.debug_unpack)
 252                opts.fn = debug_merge;
 253
 254        cache_tree_free(&active_cache_tree);
 255        for (i = 0; i < nr_trees; i++) {
 256                struct tree *tree = trees[i];
 257                parse_tree(tree);
 258                init_tree_desc(t+i, tree->buffer, tree->size);
 259        }
 260        if (unpack_trees(nr_trees, t, &opts))
 261                return 128;
 262
 263        if (opts.debug_unpack || opts.dry_run)
 264                return 0; /* do not write the index out */
 265
 266        /*
 267         * When reading only one tree (either the most basic form,
 268         * "-m ent" or "--reset ent" form), we can obtain a fully
 269         * valid cache-tree because the index must match exactly
 270         * what came from the tree.
 271         */
 272        if (nr_trees == 1 && !opts.prefix)
 273                prime_cache_tree(&the_index, trees[0]);
 274
 275        if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 276                die("unable to write new index file");
 277        return 0;
 278}