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        BUG_ON_OPT_NEG(unset);
  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        BUG_ON_OPT_NEG(unset);
  59
  60        opts = (struct unpack_trees_options *)opt->value;
  61
  62        if (opts->dir)
  63                die("more than one --exclude-per-directory given.");
  64
  65        dir = xcalloc(1, sizeof(*opts->dir));
  66        dir->flags |= DIR_SHOW_IGNORED;
  67        dir->exclude_per_dir = arg;
  68        opts->dir = dir;
  69        /* We do not need to nor want to do read-directory
  70         * here; we are merely interested in reusing the
  71         * per directory ignore stack mechanism.
  72         */
  73        return 0;
  74}
  75
  76static void debug_stage(const char *label, const struct cache_entry *ce,
  77                        struct unpack_trees_options *o)
  78{
  79        printf("%s ", label);
  80        if (!ce)
  81                printf("(missing)\n");
  82        else if (ce == o->df_conflict_entry)
  83                printf("(conflict)\n");
  84        else
  85                printf("%06o #%d %s %.8s\n",
  86                       ce->ce_mode, ce_stage(ce), ce->name,
  87                       oid_to_hex(&ce->oid));
  88}
  89
  90static int debug_merge(const struct cache_entry * const *stages,
  91                       struct unpack_trees_options *o)
  92{
  93        int i;
  94
  95        printf("* %d-way merge\n", o->merge_size);
  96        debug_stage("index", stages[0], o);
  97        for (i = 1; i <= o->merge_size; i++) {
  98                char buf[24];
  99                xsnprintf(buf, sizeof(buf), "ent#%d", i);
 100                debug_stage(buf, stages[i], o);
 101        }
 102        return 0;
 103}
 104
 105static int git_read_tree_config(const char *var, const char *value, void *cb)
 106{
 107        if (!strcmp(var, "submodule.recurse"))
 108                return git_default_submodule_config(var, value, cb);
 109
 110        return git_default_config(var, value, cb);
 111}
 112
 113int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
 114{
 115        int i, stage = 0;
 116        struct object_id oid;
 117        struct tree_desc t[MAX_UNPACK_TREES];
 118        struct unpack_trees_options opts;
 119        int prefix_set = 0;
 120        struct lock_file lock_file = LOCK_INIT;
 121        const struct option read_tree_options[] = {
 122                { OPTION_CALLBACK, 0, "index-output", NULL, N_("file"),
 123                  N_("write resulting index to <file>"),
 124                  PARSE_OPT_NONEG, index_output_cb },
 125                OPT_BOOL(0, "empty", &read_empty,
 126                            N_("only empty the index")),
 127                OPT__VERBOSE(&opts.verbose_update, N_("be verbose")),
 128                OPT_GROUP(N_("Merging")),
 129                OPT_BOOL('m', NULL, &opts.merge,
 130                         N_("perform a merge in addition to a read")),
 131                OPT_BOOL(0, "trivial", &opts.trivial_merges_only,
 132                         N_("3-way merge if no file level merging required")),
 133                OPT_BOOL(0, "aggressive", &opts.aggressive,
 134                         N_("3-way merge in presence of adds and removes")),
 135                OPT_BOOL(0, "reset", &opts.reset,
 136                         N_("same as -m, but discard unmerged entries")),
 137                { OPTION_STRING, 0, "prefix", &opts.prefix, N_("<subdirectory>/"),
 138                  N_("read the tree into the index under <subdirectory>/"),
 139                  PARSE_OPT_NONEG },
 140                OPT_BOOL('u', NULL, &opts.update,
 141                         N_("update working tree with merge result")),
 142                { OPTION_CALLBACK, 0, "exclude-per-directory", &opts,
 143                  N_("gitignore"),
 144                  N_("allow explicitly ignored files to be overwritten"),
 145                  PARSE_OPT_NONEG, exclude_per_directory_cb },
 146                OPT_BOOL('i', NULL, &opts.index_only,
 147                         N_("don't check the working tree after merging")),
 148                OPT__DRY_RUN(&opts.dry_run, N_("don't update the index or the work tree")),
 149                OPT_BOOL(0, "no-sparse-checkout", &opts.skip_sparse_checkout,
 150                         N_("skip applying sparse checkout filter")),
 151                OPT_BOOL(0, "debug-unpack", &opts.debug_unpack,
 152                         N_("debug unpack-trees")),
 153                { OPTION_CALLBACK, 0, "recurse-submodules", NULL,
 154                            "checkout", "control recursive updating of submodules",
 155                            PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater },
 156                OPT_END()
 157        };
 158
 159        memset(&opts, 0, sizeof(opts));
 160        opts.head_idx = -1;
 161        opts.src_index = &the_index;
 162        opts.dst_index = &the_index;
 163
 164        git_config(git_read_tree_config, NULL);
 165
 166        argc = parse_options(argc, argv, unused_prefix, read_tree_options,
 167                             read_tree_usage, 0);
 168
 169        hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
 170
 171        prefix_set = opts.prefix ? 1 : 0;
 172        if (1 < opts.merge + opts.reset + prefix_set)
 173                die("Which one? -m, --reset, or --prefix?");
 174
 175        /*
 176         * NEEDSWORK
 177         *
 178         * The old index should be read anyway even if we're going to
 179         * destroy all index entries because we still need to preserve
 180         * certain information such as index version or split-index
 181         * mode.
 182         */
 183
 184        if (opts.reset || opts.merge || opts.prefix) {
 185                if (read_cache_unmerged() && (opts.prefix || opts.merge))
 186                        die("You need to resolve your current index first");
 187                stage = opts.merge = 1;
 188        }
 189        resolve_undo_clear();
 190
 191        for (i = 0; i < argc; i++) {
 192                const char *arg = argv[i];
 193
 194                if (get_oid(arg, &oid))
 195                        die("Not a valid object name %s", arg);
 196                if (list_tree(&oid) < 0)
 197                        die("failed to unpack tree object %s", arg);
 198                stage++;
 199        }
 200        if (!nr_trees && !read_empty && !opts.merge)
 201                warning("read-tree: emptying the index with no arguments is deprecated; use --empty");
 202        else if (nr_trees > 0 && read_empty)
 203                die("passing trees as arguments contradicts --empty");
 204
 205        if (1 < opts.index_only + opts.update)
 206                die("-u and -i at the same time makes no sense");
 207        if ((opts.update || opts.index_only) && !opts.merge)
 208                die("%s is meaningless without -m, --reset, or --prefix",
 209                    opts.update ? "-u" : "-i");
 210        if ((opts.dir && !opts.update))
 211                die("--exclude-per-directory is meaningless unless -u");
 212        if (opts.merge && !opts.index_only)
 213                setup_work_tree();
 214
 215        if (opts.merge) {
 216                switch (stage - 1) {
 217                case 0:
 218                        die("you must specify at least one tree to merge");
 219                        break;
 220                case 1:
 221                        opts.fn = opts.prefix ? bind_merge : oneway_merge;
 222                        break;
 223                case 2:
 224                        opts.fn = twoway_merge;
 225                        opts.initial_checkout = is_cache_unborn();
 226                        break;
 227                case 3:
 228                default:
 229                        opts.fn = threeway_merge;
 230                        break;
 231                }
 232
 233                if (stage - 1 >= 3)
 234                        opts.head_idx = stage - 2;
 235                else
 236                        opts.head_idx = 1;
 237        }
 238
 239        if (opts.debug_unpack)
 240                opts.fn = debug_merge;
 241
 242        cache_tree_free(&active_cache_tree);
 243        for (i = 0; i < nr_trees; i++) {
 244                struct tree *tree = trees[i];
 245                parse_tree(tree);
 246                init_tree_desc(t+i, tree->buffer, tree->size);
 247        }
 248        if (unpack_trees(nr_trees, t, &opts))
 249                return 128;
 250
 251        if (opts.debug_unpack || opts.dry_run)
 252                return 0; /* do not write the index out */
 253
 254        /*
 255         * When reading only one tree (either the most basic form,
 256         * "-m ent" or "--reset ent" form), we can obtain a fully
 257         * valid cache-tree because the index must match exactly
 258         * what came from the tree.
 259         */
 260        if (nr_trees == 1 && !opts.prefix)
 261                prime_cache_tree(&the_index, trees[0]);
 262
 263        if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 264                die("unable to write new index file");
 265        return 0;
 266}