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#define USE_THE_INDEX_COMPATIBILITY_MACROS
   8#include "cache.h"
   9#include "config.h"
  10#include "lockfile.h"
  11#include "object.h"
  12#include "tree.h"
  13#include "tree-walk.h"
  14#include "cache-tree.h"
  15#include "unpack-trees.h"
  16#include "dir.h"
  17#include "builtin.h"
  18#include "parse-options.h"
  19#include "resolve-undo.h"
  20#include "submodule.h"
  21#include "submodule-config.h"
  22
  23static int nr_trees;
  24static int read_empty;
  25static struct tree *trees[MAX_UNPACK_TREES];
  26
  27static int list_tree(struct object_id *oid)
  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(oid);
  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        BUG_ON_OPT_NEG(unset);
  49        set_alternate_index_output(arg);
  50        return 0;
  51}
  52
  53static int exclude_per_directory_cb(const struct option *opt, const char *arg,
  54                                    int unset)
  55{
  56        struct dir_struct *dir;
  57        struct unpack_trees_options *opts;
  58
  59        BUG_ON_OPT_NEG(unset);
  60
  61        opts = (struct unpack_trees_options *)opt->value;
  62
  63        if (opts->dir)
  64                die("more than one --exclude-per-directory given.");
  65
  66        dir = xcalloc(1, sizeof(*opts->dir));
  67        dir->flags |= DIR_SHOW_IGNORED;
  68        dir->exclude_per_dir = arg;
  69        opts->dir = dir;
  70        /* We do not need to nor want to do read-directory
  71         * here; we are merely interested in reusing the
  72         * per directory ignore stack mechanism.
  73         */
  74        return 0;
  75}
  76
  77static void debug_stage(const char *label, const struct cache_entry *ce,
  78                        struct unpack_trees_options *o)
  79{
  80        printf("%s ", label);
  81        if (!ce)
  82                printf("(missing)\n");
  83        else if (ce == o->df_conflict_entry)
  84                printf("(conflict)\n");
  85        else
  86                printf("%06o #%d %s %.8s\n",
  87                       ce->ce_mode, ce_stage(ce), ce->name,
  88                       oid_to_hex(&ce->oid));
  89}
  90
  91static int debug_merge(const struct cache_entry * const *stages,
  92                       struct unpack_trees_options *o)
  93{
  94        int i;
  95
  96        printf("* %d-way merge\n", o->merge_size);
  97        debug_stage("index", stages[0], o);
  98        for (i = 1; i <= o->merge_size; i++) {
  99                char buf[24];
 100                xsnprintf(buf, sizeof(buf), "ent#%d", i);
 101                debug_stage(buf, stages[i], o);
 102        }
 103        return 0;
 104}
 105
 106static int git_read_tree_config(const char *var, const char *value, void *cb)
 107{
 108        if (!strcmp(var, "submodule.recurse"))
 109                return git_default_submodule_config(var, value, cb);
 110
 111        return git_default_config(var, value, cb);
 112}
 113
 114int cmd_read_tree(int argc, const char **argv, const char *cmd_prefix)
 115{
 116        int i, stage = 0;
 117        struct object_id oid;
 118        struct tree_desc t[MAX_UNPACK_TREES];
 119        struct unpack_trees_options opts;
 120        int prefix_set = 0;
 121        struct lock_file lock_file = LOCK_INIT;
 122        const struct option read_tree_options[] = {
 123                { OPTION_CALLBACK, 0, "index-output", NULL, N_("file"),
 124                  N_("write resulting index to <file>"),
 125                  PARSE_OPT_NONEG, index_output_cb },
 126                OPT_BOOL(0, "empty", &read_empty,
 127                            N_("only empty the index")),
 128                OPT__VERBOSE(&opts.verbose_update, N_("be verbose")),
 129                OPT_GROUP(N_("Merging")),
 130                OPT_BOOL('m', NULL, &opts.merge,
 131                         N_("perform a merge in addition to a read")),
 132                OPT_BOOL(0, "trivial", &opts.trivial_merges_only,
 133                         N_("3-way merge if no file level merging required")),
 134                OPT_BOOL(0, "aggressive", &opts.aggressive,
 135                         N_("3-way merge in presence of adds and removes")),
 136                OPT_BOOL(0, "reset", &opts.reset,
 137                         N_("same as -m, but discard unmerged entries")),
 138                { OPTION_STRING, 0, "prefix", &opts.prefix, N_("<subdirectory>/"),
 139                  N_("read the tree into the index under <subdirectory>/"),
 140                  PARSE_OPT_NONEG },
 141                OPT_BOOL('u', NULL, &opts.update,
 142                         N_("update working tree with merge result")),
 143                { OPTION_CALLBACK, 0, "exclude-per-directory", &opts,
 144                  N_("gitignore"),
 145                  N_("allow explicitly ignored files to be overwritten"),
 146                  PARSE_OPT_NONEG, exclude_per_directory_cb },
 147                OPT_BOOL('i', NULL, &opts.index_only,
 148                         N_("don't check the working tree after merging")),
 149                OPT__DRY_RUN(&opts.dry_run, N_("don't update the index or the work tree")),
 150                OPT_BOOL(0, "no-sparse-checkout", &opts.skip_sparse_checkout,
 151                         N_("skip applying sparse checkout filter")),
 152                OPT_BOOL(0, "debug-unpack", &opts.debug_unpack,
 153                         N_("debug unpack-trees")),
 154                { OPTION_CALLBACK, 0, "recurse-submodules", NULL,
 155                            "checkout", "control recursive updating of submodules",
 156                            PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater },
 157                OPT__QUIET(&opts.quiet, N_("suppress feedback messages")),
 158                OPT_END()
 159        };
 160
 161        memset(&opts, 0, sizeof(opts));
 162        opts.head_idx = -1;
 163        opts.src_index = &the_index;
 164        opts.dst_index = &the_index;
 165
 166        git_config(git_read_tree_config, NULL);
 167
 168        argc = parse_options(argc, argv, cmd_prefix, read_tree_options,
 169                             read_tree_usage, 0);
 170
 171        hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
 172
 173        prefix_set = opts.prefix ? 1 : 0;
 174        if (1 < opts.merge + opts.reset + prefix_set)
 175                die("Which one? -m, --reset, or --prefix?");
 176
 177        /*
 178         * NEEDSWORK
 179         *
 180         * The old index should be read anyway even if we're going to
 181         * destroy all index entries because we still need to preserve
 182         * certain information such as index version or split-index
 183         * mode.
 184         */
 185
 186        if (opts.reset || opts.merge || opts.prefix) {
 187                if (read_cache_unmerged() && (opts.prefix || opts.merge))
 188                        die("You need to resolve your current index first");
 189                stage = opts.merge = 1;
 190        }
 191        resolve_undo_clear();
 192
 193        for (i = 0; i < argc; i++) {
 194                const char *arg = argv[i];
 195
 196                if (get_oid(arg, &oid))
 197                        die("Not a valid object name %s", arg);
 198                if (list_tree(&oid) < 0)
 199                        die("failed to unpack tree object %s", arg);
 200                stage++;
 201        }
 202        if (!nr_trees && !read_empty && !opts.merge)
 203                warning("read-tree: emptying the index with no arguments is deprecated; use --empty");
 204        else if (nr_trees > 0 && read_empty)
 205                die("passing trees as arguments contradicts --empty");
 206
 207        if (1 < opts.index_only + opts.update)
 208                die("-u and -i at the same time makes no sense");
 209        if ((opts.update || opts.index_only) && !opts.merge)
 210                die("%s is meaningless without -m, --reset, or --prefix",
 211                    opts.update ? "-u" : "-i");
 212        if ((opts.dir && !opts.update))
 213                die("--exclude-per-directory is meaningless unless -u");
 214        if (opts.merge && !opts.index_only)
 215                setup_work_tree();
 216
 217        if (opts.merge) {
 218                switch (stage - 1) {
 219                case 0:
 220                        die("you must specify at least one tree to merge");
 221                        break;
 222                case 1:
 223                        opts.fn = opts.prefix ? bind_merge : oneway_merge;
 224                        break;
 225                case 2:
 226                        opts.fn = twoway_merge;
 227                        opts.initial_checkout = is_cache_unborn();
 228                        break;
 229                case 3:
 230                default:
 231                        opts.fn = threeway_merge;
 232                        break;
 233                }
 234
 235                if (stage - 1 >= 3)
 236                        opts.head_idx = stage - 2;
 237                else
 238                        opts.head_idx = 1;
 239        }
 240
 241        if (opts.debug_unpack)
 242                opts.fn = debug_merge;
 243
 244        cache_tree_free(&active_cache_tree);
 245        for (i = 0; i < nr_trees; i++) {
 246                struct tree *tree = trees[i];
 247                parse_tree(tree);
 248                init_tree_desc(t+i, tree->buffer, tree->size);
 249        }
 250        if (unpack_trees(nr_trees, t, &opts))
 251                return 128;
 252
 253        if (opts.debug_unpack || opts.dry_run)
 254                return 0; /* do not write the index out */
 255
 256        /*
 257         * When reading only one tree (either the most basic form,
 258         * "-m ent" or "--reset ent" form), we can obtain a fully
 259         * valid cache-tree because the index must match exactly
 260         * what came from the tree.
 261         */
 262        if (nr_trees == 1 && !opts.prefix)
 263                prime_cache_tree(the_repository,
 264                                 the_repository->index,
 265                                 trees[0]);
 266
 267        if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 268                die("unable to write new index file");
 269        return 0;
 270}