git

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/*
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 * GIT - The information manager from hell
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 *
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 * Copyright (C) Linus Torvalds, 2005
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 */
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#include "builtin.h"
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#include "config.h"
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#include "gettext.h"
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#include "hex.h"
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#include "lockfile.h"
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#include "object.h"
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#include "object-name.h"
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#include "tree.h"
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#include "tree-walk.h"
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#include "cache-tree.h"
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#include "unpack-trees.h"
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#include "parse-options.h"
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#include "repository.h"
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#include "resolve-undo.h"
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#include "setup.h"
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#include "sparse-index.h"
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#include "submodule.h"
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static int nr_trees;
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static int read_empty;
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static struct tree *trees[MAX_UNPACK_TREES];
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static int list_tree(struct object_id *oid)
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{
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	struct tree *tree;
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	if (nr_trees >= MAX_UNPACK_TREES)
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		die("I cannot read more than %d trees", MAX_UNPACK_TREES);
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	tree = parse_tree_indirect(oid);
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	if (!tree)
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		return -1;
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	trees[nr_trees++] = tree;
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	return 0;
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}
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static const char * const read_tree_usage[] = {
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	N_("git read-tree [(-m [--trivial] [--aggressive] | --reset | --prefix=<prefix>)\n"
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	   "              [-u | -i]] [--index-output=<file>] [--no-sparse-checkout]\n"
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	   "              (--empty | <tree-ish1> [<tree-ish2> [<tree-ish3>]])"),
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	NULL
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};
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static int index_output_cb(const struct option *opt UNUSED, const char *arg,
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				 int unset)
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{
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	BUG_ON_OPT_NEG(unset);
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	set_alternate_index_output(arg);
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	return 0;
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}
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static int exclude_per_directory_cb(const struct option *opt, const char *arg,
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				    int unset)
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{
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	struct unpack_trees_options *opts;
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	BUG_ON_OPT_NEG(unset);
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	opts = (struct unpack_trees_options *)opt->value;
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	if (!opts->update)
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		die("--exclude-per-directory is meaningless unless -u");
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	if (strcmp(arg, ".gitignore"))
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		die("--exclude-per-directory argument must be .gitignore");
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	return 0;
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}
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static void debug_stage(const char *label, const struct cache_entry *ce,
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			struct unpack_trees_options *o)
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{
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	printf("%s ", label);
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	if (!ce)
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		printf("(missing)\n");
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	else if (ce == o->df_conflict_entry)
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		printf("(conflict)\n");
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	else
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		printf("%06o #%d %s %.8s\n",
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		       ce->ce_mode, ce_stage(ce), ce->name,
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		       oid_to_hex(&ce->oid));
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}
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static int debug_merge(const struct cache_entry * const *stages,
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		       struct unpack_trees_options *o)
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{
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	int i;
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	printf("* %d-way merge\n", o->internal.merge_size);
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	debug_stage("index", stages[0], o);
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	for (i = 1; i <= o->internal.merge_size; i++) {
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		char buf[24];
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		xsnprintf(buf, sizeof(buf), "ent#%d", i);
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		debug_stage(buf, stages[i], o);
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	}
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	return 0;
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}
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static int git_read_tree_config(const char *var, const char *value,
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				const struct config_context *ctx, void *cb)
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{
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	if (!strcmp(var, "submodule.recurse"))
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		return git_default_submodule_config(var, value, cb);
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	return git_default_config(var, value, ctx, cb);
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}
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int cmd_read_tree(int argc, const char **argv, const char *cmd_prefix)
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{
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	int i, stage = 0;
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	struct object_id oid;
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	struct tree_desc t[MAX_UNPACK_TREES];
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	struct unpack_trees_options opts;
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	int prefix_set = 0;
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	struct lock_file lock_file = LOCK_INIT;
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	const struct option read_tree_options[] = {
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		OPT__SUPER_PREFIX(&opts.super_prefix),
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		OPT_CALLBACK_F(0, "index-output", NULL, N_("file"),
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		  N_("write resulting index to <file>"),
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		  PARSE_OPT_NONEG, index_output_cb),
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		OPT_BOOL(0, "empty", &read_empty,
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			    N_("only empty the index")),
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		OPT__VERBOSE(&opts.verbose_update, N_("be verbose")),
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		OPT_GROUP(N_("Merging")),
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		OPT_BOOL('m', NULL, &opts.merge,
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			 N_("perform a merge in addition to a read")),
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		OPT_BOOL(0, "trivial", &opts.trivial_merges_only,
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			 N_("3-way merge if no file level merging required")),
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		OPT_BOOL(0, "aggressive", &opts.aggressive,
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			 N_("3-way merge in presence of adds and removes")),
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		OPT_BOOL(0, "reset", &opts.reset,
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			 N_("same as -m, but discard unmerged entries")),
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		{ OPTION_STRING, 0, "prefix", &opts.prefix, N_("<subdirectory>/"),
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		  N_("read the tree into the index under <subdirectory>/"),
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		  PARSE_OPT_NONEG },
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		OPT_BOOL('u', NULL, &opts.update,
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			 N_("update working tree with merge result")),
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		OPT_CALLBACK_F(0, "exclude-per-directory", &opts,
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		  N_("gitignore"),
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		  N_("allow explicitly ignored files to be overwritten"),
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		  PARSE_OPT_NONEG, exclude_per_directory_cb),
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		OPT_BOOL('i', NULL, &opts.index_only,
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			 N_("don't check the working tree after merging")),
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		OPT__DRY_RUN(&opts.dry_run, N_("don't update the index or the work tree")),
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		OPT_BOOL(0, "no-sparse-checkout", &opts.skip_sparse_checkout,
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			 N_("skip applying sparse checkout filter")),
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		OPT_BOOL(0, "debug-unpack", &opts.internal.debug_unpack,
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			 N_("debug unpack-trees")),
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		OPT_CALLBACK_F(0, "recurse-submodules", NULL,
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			    "checkout", "control recursive updating of submodules",
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			    PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater),
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		OPT__QUIET(&opts.quiet, N_("suppress feedback messages")),
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		OPT_END()
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	};
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	memset(&opts, 0, sizeof(opts));
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	opts.head_idx = -1;
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	opts.src_index = the_repository->index;
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	opts.dst_index = the_repository->index;
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	git_config(git_read_tree_config, NULL);
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	argc = parse_options(argc, argv, cmd_prefix, read_tree_options,
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			     read_tree_usage, 0);
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	prefix_set = opts.prefix ? 1 : 0;
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	if (1 < opts.merge + opts.reset + prefix_set)
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		die("Which one? -m, --reset, or --prefix?");
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	/* Prefix should not start with a directory separator */
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	if (opts.prefix && opts.prefix[0] == '/')
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		die("Invalid prefix, prefix cannot start with '/'");
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	if (opts.reset)
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		opts.reset = UNPACK_RESET_OVERWRITE_UNTRACKED;
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	prepare_repo_settings(the_repository);
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	the_repository->settings.command_requires_full_index = 0;
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	repo_hold_locked_index(the_repository, &lock_file, LOCK_DIE_ON_ERROR);
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	/*
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	 * NEEDSWORK
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	 *
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	 * The old index should be read anyway even if we're going to
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	 * destroy all index entries because we still need to preserve
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	 * certain information such as index version or split-index
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	 * mode.
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	 */
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	if (opts.reset || opts.merge || opts.prefix) {
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		if (repo_read_index_unmerged(the_repository) && (opts.prefix || opts.merge))
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			die(_("You need to resolve your current index first"));
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		stage = opts.merge = 1;
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	}
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	resolve_undo_clear_index(the_repository->index);
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	for (i = 0; i < argc; i++) {
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		const char *arg = argv[i];
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		if (repo_get_oid(the_repository, arg, &oid))
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			die("Not a valid object name %s", arg);
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		if (list_tree(&oid) < 0)
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			die("failed to unpack tree object %s", arg);
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		stage++;
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	}
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	if (!nr_trees && !read_empty && !opts.merge)
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		warning("read-tree: emptying the index with no arguments is deprecated; use --empty");
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	else if (nr_trees > 0 && read_empty)
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		die("passing trees as arguments contradicts --empty");
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	if (1 < opts.index_only + opts.update)
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		die("-u and -i at the same time makes no sense");
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	if ((opts.update || opts.index_only) && !opts.merge)
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		die("%s is meaningless without -m, --reset, or --prefix",
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		    opts.update ? "-u" : "-i");
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	if (opts.update && !opts.reset)
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		opts.preserve_ignored = 0;
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	/* otherwise, opts.preserve_ignored is irrelevant */
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	if (opts.merge && !opts.index_only)
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		setup_work_tree();
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	if (opts.skip_sparse_checkout)
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		ensure_full_index(the_repository->index);
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	if (opts.merge) {
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		switch (stage - 1) {
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		case 0:
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			die("you must specify at least one tree to merge");
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			break;
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		case 1:
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			opts.fn = opts.prefix ? bind_merge : oneway_merge;
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			break;
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		case 2:
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			opts.fn = twoway_merge;
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			opts.initial_checkout = is_index_unborn(the_repository->index);
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			break;
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		case 3:
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		default:
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			opts.fn = threeway_merge;
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			break;
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		}
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		if (stage - 1 >= 3)
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			opts.head_idx = stage - 2;
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		else
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			opts.head_idx = 1;
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	}
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	if (opts.internal.debug_unpack)
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		opts.fn = debug_merge;
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	/* If we're going to prime_cache_tree later, skip cache tree update */
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	if (nr_trees == 1 && !opts.prefix)
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		opts.skip_cache_tree_update = 1;
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	cache_tree_free(&the_repository->index->cache_tree);
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	for (i = 0; i < nr_trees; i++) {
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		struct tree *tree = trees[i];
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		if (parse_tree(tree) < 0)
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			return 128;
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		init_tree_desc(t+i, &tree->object.oid, tree->buffer, tree->size);
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	}
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	if (unpack_trees(nr_trees, t, &opts))
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		return 128;
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	if (opts.internal.debug_unpack || opts.dry_run)
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		return 0; /* do not write the index out */
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	/*
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	 * When reading only one tree (either the most basic form,
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	 * "-m ent" or "--reset ent" form), we can obtain a fully
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	 * valid cache-tree because the index must match exactly
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	 * what came from the tree.
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	 */
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	if (nr_trees == 1 && !opts.prefix)
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		prime_cache_tree(the_repository,
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				 the_repository->index,
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				 trees[0]);
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	if (write_locked_index(the_repository->index, &lock_file, COMMIT_LOCK))
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		die("unable to write new index file");
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	return 0;
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}
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