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