[thirdparty/git.git] / builtin / rebase.c

/*
 * "git rebase" builtin command
 *
 * Copyright (c) 2018 Pratik Karki
 */

#include "builtin.h"
#include "run-command.h"
#include "exec-cmd.h"
#include "argv-array.h"
#include "dir.h"
#include "packfile.h"
#include "refs.h"
#include "quote.h"
#include "config.h"
#include "cache-tree.h"
#include "unpack-trees.h"
#include "lockfile.h"
#include "parse-options.h"
#include "commit.h"
#include "diff.h"
#include "wt-status.h"
#include "revision.h"

static char const * const builtin_rebase_usage[] = {
	N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
		"[<upstream>] [<branch>]"),
	N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
		"--root [<branch>]"),
	N_("git rebase --continue | --abort | --skip | --edit-todo"),
	NULL
};

static GIT_PATH_FUNC(apply_dir, "rebase-apply")
static GIT_PATH_FUNC(merge_dir, "rebase-merge")

enum rebase_type {
	REBASE_UNSPECIFIED = -1,
	REBASE_AM,
	REBASE_MERGE,
	REBASE_INTERACTIVE,
	REBASE_PRESERVE_MERGES
};

static int use_builtin_rebase(void)
{
	struct child_process cp = CHILD_PROCESS_INIT;
	struct strbuf out = STRBUF_INIT;
	int ret;

	argv_array_pushl(&cp.args,
			 "config", "--bool", "rebase.usebuiltin", NULL);
	cp.git_cmd = 1;
	if (capture_command(&cp, &out, 6)) {
		strbuf_release(&out);
		return 0;
	}

	strbuf_trim(&out);
	ret = !strcmp("true", out.buf);
	strbuf_release(&out);
	return ret;
}

static int apply_autostash(void)
{
	warning("TODO");
	return 0;
}

struct rebase_options {
	enum rebase_type type;
	const char *state_dir;
	struct commit *upstream;
	const char *upstream_name;
	const char *upstream_arg;
	char *head_name;
	struct object_id orig_head;
	struct commit *onto;
	const char *onto_name;
	const char *revisions;
	int root;
	struct commit *restrict_revision;
	int dont_finish_rebase;
	enum {
		REBASE_NO_QUIET = 1<<0,
		REBASE_VERBOSE = 1<<1,
		REBASE_DIFFSTAT = 1<<2,
	} flags;
	struct strbuf git_am_opt;
};

static int is_interactive(struct rebase_options *opts)
{
	return opts->type == REBASE_INTERACTIVE ||
		opts->type == REBASE_PRESERVE_MERGES;
}

/* Returns the filename prefixed by the state_dir */
static const char *state_dir_path(const char *filename, struct rebase_options *opts)
{
	static struct strbuf path = STRBUF_INIT;
	static size_t prefix_len;

	if (!prefix_len) {
		strbuf_addf(&path, "%s/", opts->state_dir);
		prefix_len = path.len;
	}

	strbuf_setlen(&path, prefix_len);
	strbuf_addstr(&path, filename);
	return path.buf;
}

static int finish_rebase(struct rebase_options *opts)
{
	struct strbuf dir = STRBUF_INIT;
	const char *argv_gc_auto[] = { "gc", "--auto", NULL };

	delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
	apply_autostash();
	close_all_packs(the_repository->objects);
	/*
	 * We ignore errors in 'gc --auto', since the
	 * user should see them.
	 */
	run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
	strbuf_addstr(&dir, opts->state_dir);
	remove_dir_recursively(&dir, 0);
	strbuf_release(&dir);

	return 0;
}

static struct commit *peel_committish(const char *name)
{
	struct object *obj;
	struct object_id oid;

	if (get_oid(name, &oid))
		return NULL;
	obj = parse_object(the_repository, &oid);
	return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
}

static void add_var(struct strbuf *buf, const char *name, const char *value)
{
	if (!value)
		strbuf_addf(buf, "unset %s; ", name);
	else {
		strbuf_addf(buf, "%s=", name);
		sq_quote_buf(buf, value);
		strbuf_addstr(buf, "; ");
	}
}

static int run_specific_rebase(struct rebase_options *opts)
{
	const char *argv[] = { NULL, NULL };
	struct strbuf script_snippet = STRBUF_INIT;
	int status;
	const char *backend, *backend_func;

	add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
	add_var(&script_snippet, "state_dir", opts->state_dir);

	add_var(&script_snippet, "upstream_name", opts->upstream_name);
	add_var(&script_snippet, "upstream",
				 oid_to_hex(&opts->upstream->object.oid));
	add_var(&script_snippet, "head_name", opts->head_name);
	add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
	add_var(&script_snippet, "onto", oid_to_hex(&opts->onto->object.oid));
	add_var(&script_snippet, "onto_name", opts->onto_name);
	add_var(&script_snippet, "revisions", opts->revisions);
	add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
		oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
	add_var(&script_snippet, "GIT_QUIET",
		opts->flags & REBASE_NO_QUIET ? "" : "t");
	add_var(&script_snippet, "git_am_opt", opts->git_am_opt.buf);
	add_var(&script_snippet, "verbose",
		opts->flags & REBASE_VERBOSE ? "t" : "");
	add_var(&script_snippet, "diffstat",
		opts->flags & REBASE_DIFFSTAT ? "t" : "");

	switch (opts->type) {
	case REBASE_AM:
		backend = "git-rebase--am";
		backend_func = "git_rebase__am";
		break;
	case REBASE_INTERACTIVE:
		backend = "git-rebase--interactive";
		backend_func = "git_rebase__interactive";
		break;
	case REBASE_MERGE:
		backend = "git-rebase--merge";
		backend_func = "git_rebase__merge";
		break;
	case REBASE_PRESERVE_MERGES:
		backend = "git-rebase--preserve-merges";
		backend_func = "git_rebase__preserve_merges";
		break;
	default:
		BUG("Unhandled rebase type %d", opts->type);
		break;
	}

	strbuf_addf(&script_snippet,
		    ". git-sh-setup && . git-rebase--common &&"
		    " . %s && %s", backend, backend_func);
	argv[0] = script_snippet.buf;

	status = run_command_v_opt(argv, RUN_USING_SHELL);
	if (opts->dont_finish_rebase)
		; /* do nothing */
	else if (status == 0) {
		if (!file_exists(state_dir_path("stopped-sha", opts)))
			finish_rebase(opts);
	} else if (status == 2) {
		struct strbuf dir = STRBUF_INIT;

		apply_autostash();
		strbuf_addstr(&dir, opts->state_dir);
		remove_dir_recursively(&dir, 0);
		strbuf_release(&dir);
		die("Nothing to do");
	}

	strbuf_release(&script_snippet);

	return status ? -1 : 0;
}

#define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"

static int reset_head(struct object_id *oid, const char *action,
		      const char *switch_to_branch, int detach_head)
{
	struct object_id head_oid;
	struct tree_desc desc;
	struct lock_file lock = LOCK_INIT;
	struct unpack_trees_options unpack_tree_opts;
	struct tree *tree;
	const char *reflog_action;
	struct strbuf msg = STRBUF_INIT;
	size_t prefix_len;
	struct object_id *orig = NULL, oid_orig,
		*old_orig = NULL, oid_old_orig;
	int ret = 0;

	if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0)
		return -1;

	if (!oid) {
		if (get_oid("HEAD", &head_oid)) {
			rollback_lock_file(&lock);
			return error(_("could not determine HEAD revision"));
		}
		oid = &head_oid;
	}

	memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
	setup_unpack_trees_porcelain(&unpack_tree_opts, action);
	unpack_tree_opts.head_idx = 1;
	unpack_tree_opts.src_index = the_repository->index;
	unpack_tree_opts.dst_index = the_repository->index;
	unpack_tree_opts.fn = oneway_merge;
	unpack_tree_opts.update = 1;
	unpack_tree_opts.merge = 1;
	if (!detach_head)
		unpack_tree_opts.reset = 1;

	if (read_index_unmerged(the_repository->index) < 0) {
		rollback_lock_file(&lock);
		return error(_("could not read index"));
	}

	if (!fill_tree_descriptor(&desc, oid)) {
		error(_("failed to find tree of %s"), oid_to_hex(oid));
		rollback_lock_file(&lock);
		free((void *)desc.buffer);
		return -1;
	}

	if (unpack_trees(1, &desc, &unpack_tree_opts)) {
		rollback_lock_file(&lock);
		free((void *)desc.buffer);
		return -1;
	}

	tree = parse_tree_indirect(oid);
	prime_cache_tree(the_repository->index, tree);

	if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0)
		ret = error(_("could not write index"));
	free((void *)desc.buffer);

	if (ret)
		return ret;

	reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
	strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
	prefix_len = msg.len;

	if (!get_oid("ORIG_HEAD", &oid_old_orig))
		old_orig = &oid_old_orig;
	if (!get_oid("HEAD", &oid_orig)) {
		orig = &oid_orig;
		strbuf_addstr(&msg, "updating ORIG_HEAD");
		update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0,
			   UPDATE_REFS_MSG_ON_ERR);
	} else if (old_orig)
		delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
	strbuf_setlen(&msg, prefix_len);
	strbuf_addstr(&msg, "updating HEAD");
	if (!switch_to_branch)
		ret = update_ref(msg.buf, "HEAD", oid, orig, REF_NO_DEREF,
				 UPDATE_REFS_MSG_ON_ERR);
	else {
		ret = create_symref("HEAD", switch_to_branch, msg.buf);
		if (!ret)
			ret = update_ref(msg.buf, "HEAD", oid, NULL, 0,
					 UPDATE_REFS_MSG_ON_ERR);
	}

	strbuf_release(&msg);
	return ret;
}

static int rebase_config(const char *var, const char *value, void *data)
{
	struct rebase_options *opts = data;

	if (!strcmp(var, "rebase.stat")) {
		if (git_config_bool(var, value))
			opts->flags |= REBASE_DIFFSTAT;
		else
			opts->flags &= !REBASE_DIFFSTAT;
		return 0;
	}

	return git_default_config(var, value, data);
}

/*
 * Determines whether the commits in from..to are linear, i.e. contain
 * no merge commits. This function *expects* `from` to be an ancestor of
 * `to`.
 */
static int is_linear_history(struct commit *from, struct commit *to)
{
	while (to && to != from) {
		parse_commit(to);
		if (!to->parents)
			return 1;
		if (to->parents->next)
			return 0;
		to = to->parents->item;
	}
	return 1;
}

static int can_fast_forward(struct commit *onto, struct object_id *head_oid,
			    struct object_id *merge_base)
{
	struct commit *head = lookup_commit(the_repository, head_oid);
	struct commit_list *merge_bases;
	int res;

	if (!head)
		return 0;

	merge_bases = get_merge_bases(onto, head);
	if (merge_bases && !merge_bases->next) {
		oidcpy(merge_base, &merge_bases->item->object.oid);
		res = !oidcmp(merge_base, &onto->object.oid);
	} else {
		oidcpy(merge_base, &null_oid);
		res = 0;
	}
	free_commit_list(merge_bases);
	return res && is_linear_history(onto, head);
}

int cmd_rebase(int argc, const char **argv, const char *prefix)
{
	struct rebase_options options = {
		.type = REBASE_UNSPECIFIED,
		.flags = REBASE_NO_QUIET,
		.git_am_opt = STRBUF_INIT,
	};
	const char *branch_name;
	int ret, flags;
	int ok_to_skip_pre_rebase = 0;
	struct strbuf msg = STRBUF_INIT;
	struct strbuf revisions = STRBUF_INIT;
	struct object_id merge_base;
	struct option builtin_rebase_options[] = {
		OPT_STRING(0, "onto", &options.onto_name,
			   N_("revision"),
			   N_("rebase onto given branch instead of upstream")),
		OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
			 N_("allow pre-rebase hook to run")),
		OPT_NEGBIT('q', "quiet", &options.flags,
			   N_("be quiet. implies --no-stat"),
			   REBASE_NO_QUIET| REBASE_VERBOSE | REBASE_DIFFSTAT),
		OPT_BIT('v', "verbose", &options.flags,
			N_("display a diffstat of what changed upstream"),
			REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
		{OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
			N_("do not show diffstat of what changed upstream"),
			PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
		OPT_END(),
	};

	/*
	 * NEEDSWORK: Once the builtin rebase has been tested enough
	 * and git-legacy-rebase.sh is retired to contrib/, this preamble
	 * can be removed.
	 */

	if (!use_builtin_rebase()) {
		const char *path = mkpath("%s/git-legacy-rebase",
					  git_exec_path());

		if (sane_execvp(path, (char **)argv) < 0)
			die_errno(_("could not exec %s"), path);
		else
			BUG("sane_execvp() returned???");
	}

	if (argc == 2 && !strcmp(argv[1], "-h"))
		usage_with_options(builtin_rebase_usage,
				   builtin_rebase_options);

	prefix = setup_git_directory();
	trace_repo_setup(prefix);
	setup_work_tree();

	git_config(rebase_config, &options);

	argc = parse_options(argc, argv, prefix,
			     builtin_rebase_options,
			     builtin_rebase_usage, 0);

	if (argc > 2)
		usage_with_options(builtin_rebase_usage,
				   builtin_rebase_options);

	if (!(options.flags & REBASE_NO_QUIET))
		strbuf_addstr(&options.git_am_opt, " -q");

	switch (options.type) {
	case REBASE_MERGE:
	case REBASE_INTERACTIVE:
	case REBASE_PRESERVE_MERGES:
		options.state_dir = merge_dir();
		break;
	case REBASE_AM:
		options.state_dir = apply_dir();
		break;
	default:
		/* the default rebase backend is `--am` */
		options.type = REBASE_AM;
		options.state_dir = apply_dir();
		break;
	}

	if (!options.root) {
		if (argc < 1)
			die("TODO: handle @{upstream}");
		else {
			options.upstream_name = argv[0];
			argc--;
			argv++;
			if (!strcmp(options.upstream_name, "-"))
				options.upstream_name = "@{-1}";
		}
		options.upstream = peel_committish(options.upstream_name);
		if (!options.upstream)
			die(_("invalid upstream '%s'"), options.upstream_name);
		options.upstream_arg = options.upstream_name;
	} else
		die("TODO: upstream for --root");

	/* Make sure the branch to rebase onto is valid. */
	if (!options.onto_name)
		options.onto_name = options.upstream_name;
	if (strstr(options.onto_name, "...")) {
		if (get_oid_mb(options.onto_name, &merge_base) < 0)
			die(_("'%s': need exactly one merge base"),
			    options.onto_name);
		options.onto = lookup_commit_or_die(&merge_base,
						    options.onto_name);
	} else {
		options.onto = peel_committish(options.onto_name);
		if (!options.onto)
			die(_("Does not point to a valid commit '%s'"),
				options.onto_name);
	}

	/*
	 * If the branch to rebase is given, that is the branch we will rebase
	 * branch_name -- branch/commit being rebased, or
	 * 		  HEAD (already detached)
	 * orig_head -- commit object name of tip of the branch before rebasing
	 * head_name -- refs/heads/<that-branch> or "detached HEAD"
	 */
	if (argc > 0)
		 die("TODO: handle switch_to");
	else {
		/* Do not need to switch branches, we are already on it. */
		options.head_name =
			xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
					 &flags));
		if (!options.head_name)
			die(_("No such ref: %s"), "HEAD");
		if (flags & REF_ISSYMREF) {
			if (!skip_prefix(options.head_name,
					 "refs/heads/", &branch_name))
				branch_name = options.head_name;

		} else {
			options.head_name = xstrdup("detached HEAD");
			branch_name = "HEAD";
		}
		if (get_oid("HEAD", &options.orig_head))
			die(_("Could not resolve HEAD to a revision"));
	}

	if (read_index(the_repository->index) < 0)
		die(_("could not read index"));

	if (require_clean_work_tree("rebase",
				    _("Please commit or stash them."), 1, 1)) {
		ret = 1;
		goto cleanup;
	}

	/*
	 * Now we are rebasing commits upstream..orig_head (or with --root,
	 * everything leading up to orig_head) on top of onto.
	 */

	/*
	 * Check if we are already based on onto with linear history,
	 * but this should be done only when upstream and onto are the same
	 * and if this is not an interactive rebase.
	 */
	if (can_fast_forward(options.onto, &options.orig_head, &merge_base) &&
	    !is_interactive(&options) && !options.restrict_revision &&
	    !oidcmp(&options.upstream->object.oid, &options.onto->object.oid)) {
		int flag;

		if (!(options.flags & REBASE_NO_QUIET))
			; /* be quiet */
		else if (!strcmp(branch_name, "HEAD") &&
			 resolve_ref_unsafe("HEAD", 0, NULL, &flag))
			puts(_("HEAD is up to date, rebase forced."));
		else
			printf(_("Current branch %s is up to date, rebase "
				 "forced.\n"), branch_name);
	}

	/* If a hook exists, give it a chance to interrupt*/
	if (!ok_to_skip_pre_rebase &&
	    run_hook_le(NULL, "pre-rebase", options.upstream_arg,
			argc ? argv[0] : NULL, NULL))
		die(_("The pre-rebase hook refused to rebase."));

	if (options.flags & REBASE_DIFFSTAT) {
		struct diff_options opts;

		if (options.flags & REBASE_VERBOSE)
			printf(_("Changes from %s to %s:\n"),
				oid_to_hex(&merge_base),
				oid_to_hex(&options.onto->object.oid));

		/* We want color (if set), but no pager */
		diff_setup(&opts);
		opts.stat_width = -1; /* use full terminal width */
		opts.stat_graph_width = -1; /* respect statGraphWidth config */
		opts.output_format |=
			DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
		opts.detect_rename = DIFF_DETECT_RENAME;
		diff_setup_done(&opts);
		diff_tree_oid(&merge_base, &options.onto->object.oid,
			      "", &opts);
		diffcore_std(&opts);
		diff_flush(&opts);
	}

	/* Detach HEAD and reset the tree */
	if (options.flags & REBASE_NO_QUIET)
		printf(_("First, rewinding head to replay your work on top of "
			 "it...\n"));

	strbuf_addf(&msg, "rebase: checkout %s", options.onto_name);
	if (reset_head(&options.onto->object.oid, "checkout", NULL, 1))
		die(_("Could not detach HEAD"));
	strbuf_release(&msg);

	strbuf_addf(&revisions, "%s..%s",
		    options.root ? oid_to_hex(&options.onto->object.oid) :
		    (options.restrict_revision ?
		     oid_to_hex(&options.restrict_revision->object.oid) :
		     oid_to_hex(&options.upstream->object.oid)),
		    oid_to_hex(&options.orig_head));

	options.revisions = revisions.buf;

	ret = !!run_specific_rebase(&options);

cleanup:
	strbuf_release(&revisions);
	free(options.head_name);
	return ret;
}
Commit	Line	Data
55071ea2 PK	1	/*
	2	* "git rebase" builtin command
	3	*
	4	* Copyright (c) 2018 Pratik Karki
	5	*/
	6
	7	#include "builtin.h"
	8	#include "run-command.h"
	9	#include "exec-cmd.h"
	10	#include "argv-array.h"
	11	#include "dir.h"
ac7f467f PK	12	#include "packfile.h"
	13	#include "refs.h"
	14	#include "quote.h"
	15	#include "config.h"
	16	#include "cache-tree.h"
	17	#include "unpack-trees.h"
	18	#include "lockfile.h"
f28d40d3	19	#include "parse-options.h"
075bc852	20	#include "commit.h"
bff014da	21	#include "diff.h"
e0333e5c	22	#include "wt-status.h"
9a48a615	23	#include "revision.h"
f28d40d3 PK	24
	25	static char const * const builtin_rebase_usage[] = {
	26	N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
	27	"[<upstream>] [<branch>]"),
	28	N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
	29	"--root [<branch>]"),
	30	N_("git rebase --continue \| --abort \| --skip \| --edit-todo"),
	31	NULL
	32	};
ac7f467f PK	33
	34	static GIT_PATH_FUNC(apply_dir, "rebase-apply")
	35	static GIT_PATH_FUNC(merge_dir, "rebase-merge")
	36
	37	enum rebase_type {
	38	REBASE_UNSPECIFIED = -1,
	39	REBASE_AM,
	40	REBASE_MERGE,
	41	REBASE_INTERACTIVE,
	42	REBASE_PRESERVE_MERGES
	43	};
55071ea2 PK	44
	45	static int use_builtin_rebase(void)
	46	{
	47	struct child_process cp = CHILD_PROCESS_INIT;
	48	struct strbuf out = STRBUF_INIT;
	49	int ret;
	50
	51	argv_array_pushl(&cp.args,
	52	"config", "--bool", "rebase.usebuiltin", NULL);
	53	cp.git_cmd = 1;
	54	if (capture_command(&cp, &out, 6)) {
	55	strbuf_release(&out);
	56	return 0;
	57	}
	58
	59	strbuf_trim(&out);
	60	ret = !strcmp("true", out.buf);
	61	strbuf_release(&out);
	62	return ret;
	63	}
	64
ac7f467f PK	65	static int apply_autostash(void)
	66	{
	67	warning("TODO");
	68	return 0;
	69	}
	70
	71	struct rebase_options {
	72	enum rebase_type type;
	73	const char *state_dir;
	74	struct commit *upstream;
	75	const char *upstream_name;
06e4775a	76	const char *upstream_arg;
ac7f467f PK	77	char *head_name;
	78	struct object_id orig_head;
	79	struct commit *onto;
	80	const char *onto_name;
	81	const char *revisions;
	82	int root;
	83	struct commit *restrict_revision;
	84	int dont_finish_rebase;
b4c8eb02 PK	85	enum {
b4c8eb02 PK	86	REBASE_NO_QUIET = 1<<0,
bff014da PK	87	REBASE_VERBOSE = 1<<1,
bff014da PK	88	REBASE_DIFFSTAT = 1<<2,
b4c8eb02 PK	89	} flags;
b4c8eb02 PK	90	struct strbuf git_am_opt;
ac7f467f PK	91	};
ac7f467f PK	92
9a48a615 PK	93	static int is_interactive(struct rebase_options *opts)
	94	{
	95	return opts->type == REBASE_INTERACTIVE \|\|
	96	opts->type == REBASE_PRESERVE_MERGES;
	97	}
	98
ac7f467f PK	99	/* Returns the filename prefixed by the state_dir */
	100	static const char state_dir_path(const char filename, struct rebase_options *opts)
	101	{
	102	static struct strbuf path = STRBUF_INIT;
	103	static size_t prefix_len;
	104
	105	if (!prefix_len) {
	106	strbuf_addf(&path, "%s/", opts->state_dir);
	107	prefix_len = path.len;
	108	}
	109
	110	strbuf_setlen(&path, prefix_len);
	111	strbuf_addstr(&path, filename);
	112	return path.buf;
	113	}
	114
	115	static int finish_rebase(struct rebase_options *opts)
	116	{
	117	struct strbuf dir = STRBUF_INIT;
	118	const char *argv_gc_auto[] = { "gc", "--auto", NULL };
	119
	120	delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
	121	apply_autostash();
	122	close_all_packs(the_repository->objects);
	123	/*
	124	* We ignore errors in 'gc --auto', since the
	125	* user should see them.
	126	*/
	127	run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
	128	strbuf_addstr(&dir, opts->state_dir);
	129	remove_dir_recursively(&dir, 0);
	130	strbuf_release(&dir);
	131
	132	return 0;
	133	}
	134
	135	static struct commit peel_committish(const char name)
	136	{
	137	struct object *obj;
	138	struct object_id oid;
	139
	140	if (get_oid(name, &oid))
	141	return NULL;
	142	obj = parse_object(the_repository, &oid);
	143	return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
	144	}
	145
	146	static void add_var(struct strbuf buf, const char name, const char *value)
	147	{
	148	if (!value)
	149	strbuf_addf(buf, "unset %s; ", name);
	150	else {
	151	strbuf_addf(buf, "%s=", name);
	152	sq_quote_buf(buf, value);
	153	strbuf_addstr(buf, "; ");
	154	}
	155	}
	156
	157	static int run_specific_rebase(struct rebase_options *opts)
	158	{
	159	const char *argv[] = { NULL, NULL };
	160	struct strbuf script_snippet = STRBUF_INIT;
	161	int status;
	162	const char backend, backend_func;
163
164	add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
165	add_var(&script_snippet, "state_dir", opts->state_dir);
166
167	add_var(&script_snippet, "upstream_name", opts->upstream_name);
168	add_var(&script_snippet, "upstream",
169	oid_to_hex(&opts->upstream->object.oid));
170	add_var(&script_snippet, "head_name", opts->head_name);
171	add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
172	add_var(&script_snippet, "onto", oid_to_hex(&opts->onto->object.oid));
173	add_var(&script_snippet, "onto_name", opts->onto_name);
174	add_var(&script_snippet, "revisions", opts->revisions);
175	add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
176	oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
b4c8eb02 PK	177	add_var(&script_snippet, "GIT_QUIET",
	178	opts->flags & REBASE_NO_QUIET ? "" : "t");
	179	add_var(&script_snippet, "git_am_opt", opts->git_am_opt.buf);
bff014da PK	180	add_var(&script_snippet, "verbose",
	181	opts->flags & REBASE_VERBOSE ? "t" : "");
	182	add_var(&script_snippet, "diffstat",
	183	opts->flags & REBASE_DIFFSTAT ? "t" : "");
ac7f467f PK	184
	185	switch (opts->type) {
	186	case REBASE_AM:
	187	backend = "git-rebase--am";
	188	backend_func = "git_rebase__am";
	189	break;
	190	case REBASE_INTERACTIVE:
	191	backend = "git-rebase--interactive";
	192	backend_func = "git_rebase__interactive";
	193	break;
	194	case REBASE_MERGE:
	195	backend = "git-rebase--merge";
	196	backend_func = "git_rebase__merge";
	197	break;
	198	case REBASE_PRESERVE_MERGES:
	199	backend = "git-rebase--preserve-merges";
	200	backend_func = "git_rebase__preserve_merges";
	201	break;
	202	default:
	203	BUG("Unhandled rebase type %d", opts->type);
	204	break;
	205	}
	206
	207	strbuf_addf(&script_snippet,
	208	". git-sh-setup && . git-rebase--common &&"
	209	" . %s && %s", backend, backend_func);
	210	argv[0] = script_snippet.buf;
	211
	212	status = run_command_v_opt(argv, RUN_USING_SHELL);
	213	if (opts->dont_finish_rebase)
	214	; /* do nothing */
	215	else if (status == 0) {
	216	if (!file_exists(state_dir_path("stopped-sha", opts)))
	217	finish_rebase(opts);
	218	} else if (status == 2) {
	219	struct strbuf dir = STRBUF_INIT;
	220
	221	apply_autostash();
	222	strbuf_addstr(&dir, opts->state_dir);
	223	remove_dir_recursively(&dir, 0);
	224	strbuf_release(&dir);
	225	die("Nothing to do");
	226	}
	227
	228	strbuf_release(&script_snippet);
	229
	230	return status ? -1 : 0;
	231	}
	232
	233	#define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
	234
	235	static int reset_head(struct object_id oid, const char action,
	236	const char *switch_to_branch, int detach_head)
	237	{
	238	struct object_id head_oid;
	239	struct tree_desc desc;
	240	struct lock_file lock = LOCK_INIT;
	241	struct unpack_trees_options unpack_tree_opts;
	242	struct tree *tree;
	243	const char *reflog_action;
	244	struct strbuf msg = STRBUF_INIT;
	245	size_t prefix_len;
	246	struct object_id *orig = NULL, oid_orig,
	247	*old_orig = NULL, oid_old_orig;
248	int ret = 0;
249
250	if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0)
251	return -1;
252
253	if (!oid) {
254	if (get_oid("HEAD", &head_oid)) {
255	rollback_lock_file(&lock);
256	return error(_("could not determine HEAD revision"));
257	}
258	oid = &head_oid;
259	}
260
261	memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
262	setup_unpack_trees_porcelain(&unpack_tree_opts, action);
263	unpack_tree_opts.head_idx = 1;
264	unpack_tree_opts.src_index = the_repository->index;
265	unpack_tree_opts.dst_index = the_repository->index;
266	unpack_tree_opts.fn = oneway_merge;
267	unpack_tree_opts.update = 1;
268	unpack_tree_opts.merge = 1;
269	if (!detach_head)
270	unpack_tree_opts.reset = 1;
271
272	if (read_index_unmerged(the_repository->index) < 0) {
273	rollback_lock_file(&lock);
274	return error(_("could not read index"));
275	}
276
277	if (!fill_tree_descriptor(&desc, oid)) {
278	error(_("failed to find tree of %s"), oid_to_hex(oid));
279	rollback_lock_file(&lock);
280	free((void *)desc.buffer);
281	return -1;
282	}
283
284	if (unpack_trees(1, &desc, &unpack_tree_opts)) {
285	rollback_lock_file(&lock);
286	free((void *)desc.buffer);
287	return -1;
288	}
289
290	tree = parse_tree_indirect(oid);
291	prime_cache_tree(the_repository->index, tree);
292
293	if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0)
294	ret = error(_("could not write index"));
295	free((void *)desc.buffer);
296
297	if (ret)
298	return ret;
299
300	reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
301	strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
302	prefix_len = msg.len;
303
304	if (!get_oid("ORIG_HEAD", &oid_old_orig))
305	old_orig = &oid_old_orig;
306	if (!get_oid("HEAD", &oid_orig)) {
307	orig = &oid_orig;
308	strbuf_addstr(&msg, "updating ORIG_HEAD");
309	update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0,
310	UPDATE_REFS_MSG_ON_ERR);
311	} else if (old_orig)
312	delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
313	strbuf_setlen(&msg, prefix_len);
314	strbuf_addstr(&msg, "updating HEAD");
315	if (!switch_to_branch)
316	ret = update_ref(msg.buf, "HEAD", oid, orig, REF_NO_DEREF,
317	UPDATE_REFS_MSG_ON_ERR);
318	else {
319	ret = create_symref("HEAD", switch_to_branch, msg.buf);
320	if (!ret)
321	ret = update_ref(msg.buf, "HEAD", oid, NULL, 0,
322	UPDATE_REFS_MSG_ON_ERR);
323	}
324
325	strbuf_release(&msg);
326	return ret;
327	}
328
bff014da PK	329	static int rebase_config(const char var, const char value, void *data)
	330	{
	331	struct rebase_options *opts = data;
	332
	333	if (!strcmp(var, "rebase.stat")) {
	334	if (git_config_bool(var, value))
	335	opts->flags \|= REBASE_DIFFSTAT;
	336	else
	337	opts->flags &= !REBASE_DIFFSTAT;
	338	return 0;
	339	}
	340
	341	return git_default_config(var, value, data);
	342	}
	343
9a48a615 PK	344	/*
	345	* Determines whether the commits in from..to are linear, i.e. contain
	346	* no merge commits. This function expects `from` to be an ancestor of
	347	* `to`.
	348	*/
	349	static int is_linear_history(struct commit from, struct commit to)
	350	{
	351	while (to && to != from) {
	352	parse_commit(to);
	353	if (!to->parents)
	354	return 1;
	355	if (to->parents->next)
	356	return 0;
	357	to = to->parents->item;
	358	}
	359	return 1;
	360	}
	361
	362	static int can_fast_forward(struct commit onto, struct object_id head_oid,
	363	struct object_id *merge_base)
	364	{
	365	struct commit *head = lookup_commit(the_repository, head_oid);
	366	struct commit_list *merge_bases;
	367	int res;
	368
	369	if (!head)
	370	return 0;
	371
	372	merge_bases = get_merge_bases(onto, head);
	373	if (merge_bases && !merge_bases->next) {
	374	oidcpy(merge_base, &merge_bases->item->object.oid);
	375	res = !oidcmp(merge_base, &onto->object.oid);
	376	} else {
	377	oidcpy(merge_base, &null_oid);
	378	res = 0;
	379	}
	380	free_commit_list(merge_bases);
	381	return res && is_linear_history(onto, head);
	382	}
	383
55071ea2 PK	384	int cmd_rebase(int argc, const char *argv, const char prefix)
55071ea2 PK	385	{
ac7f467f PK	386	struct rebase_options options = {
ac7f467f PK	387	.type = REBASE_UNSPECIFIED,
b4c8eb02 PK	388	.flags = REBASE_NO_QUIET,
b4c8eb02 PK	389	.git_am_opt = STRBUF_INIT,
ac7f467f PK	390	};
	391	const char *branch_name;
	392	int ret, flags;
06e4775a	393	int ok_to_skip_pre_rebase = 0;
ac7f467f PK	394	struct strbuf msg = STRBUF_INIT;
ac7f467f PK	395	struct strbuf revisions = STRBUF_INIT;
075bc852	396	struct object_id merge_base;
f28d40d3 PK	397	struct option builtin_rebase_options[] = {
	398	OPT_STRING(0, "onto", &options.onto_name,
	399	N_("revision"),
	400	N_("rebase onto given branch instead of upstream")),
06e4775a PK	401	OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
06e4775a PK	402	N_("allow pre-rebase hook to run")),
b4c8eb02 PK	403	OPT_NEGBIT('q', "quiet", &options.flags,
b4c8eb02 PK	404	N_("be quiet. implies --no-stat"),
bff014da PK	405	REBASE_NO_QUIET\| REBASE_VERBOSE \| REBASE_DIFFSTAT),
	406	OPT_BIT('v', "verbose", &options.flags,
	407	N_("display a diffstat of what changed upstream"),
	408	REBASE_NO_QUIET \| REBASE_VERBOSE \| REBASE_DIFFSTAT),
	409	{OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
	410	N_("do not show diffstat of what changed upstream"),
	411	PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
f28d40d3 PK	412	OPT_END(),
f28d40d3 PK	413	};
ac7f467f	414
55071ea2 PK	415	/*
	416	* NEEDSWORK: Once the builtin rebase has been tested enough
	417	* and git-legacy-rebase.sh is retired to contrib/, this preamble
	418	* can be removed.
	419	*/
	420
	421	if (!use_builtin_rebase()) {
	422	const char *path = mkpath("%s/git-legacy-rebase",
	423	git_exec_path());
	424
	425	if (sane_execvp(path, (char **)argv) < 0)
	426	die_errno(_("could not exec %s"), path);
	427	else
	428	BUG("sane_execvp() returned???");
	429	}
	430
f28d40d3 PK	431	if (argc == 2 && !strcmp(argv[1], "-h"))
	432	usage_with_options(builtin_rebase_usage,
	433	builtin_rebase_options);
	434
55071ea2 PK	435	prefix = setup_git_directory();
	436	trace_repo_setup(prefix);
	437	setup_work_tree();
	438
bff014da PK	439	git_config(rebase_config, &options);
bff014da PK	440
f28d40d3 PK	441	argc = parse_options(argc, argv, prefix,
	442	builtin_rebase_options,
	443	builtin_rebase_usage, 0);
	444
	445	if (argc > 2)
	446	usage_with_options(builtin_rebase_usage,
	447	builtin_rebase_options);
ac7f467f	448
b4c8eb02 PK	449	if (!(options.flags & REBASE_NO_QUIET))
	450	strbuf_addstr(&options.git_am_opt, " -q");
	451
ac7f467f PK	452	switch (options.type) {
	453	case REBASE_MERGE:
	454	case REBASE_INTERACTIVE:
	455	case REBASE_PRESERVE_MERGES:
	456	options.state_dir = merge_dir();
	457	break;
	458	case REBASE_AM:
	459	options.state_dir = apply_dir();
	460	break;
	461	default:
	462	/* the default rebase backend is `--am` */
	463	options.type = REBASE_AM;
	464	options.state_dir = apply_dir();
	465	break;
	466	}
	467
	468	if (!options.root) {
f28d40d3	469	if (argc < 1)
ac7f467f PK	470	die("TODO: handle @{upstream}");
ac7f467f PK	471	else {
f28d40d3	472	options.upstream_name = argv[0];
ac7f467f PK	473	argc--;
	474	argv++;
	475	if (!strcmp(options.upstream_name, "-"))
	476	options.upstream_name = "@{-1}";
	477	}
	478	options.upstream = peel_committish(options.upstream_name);
	479	if (!options.upstream)
	480	die(_("invalid upstream '%s'"), options.upstream_name);
06e4775a	481	options.upstream_arg = options.upstream_name;
ac7f467f PK	482	} else
	483	die("TODO: upstream for --root");
	484
	485	/* Make sure the branch to rebase onto is valid. */
	486	if (!options.onto_name)
	487	options.onto_name = options.upstream_name;
	488	if (strstr(options.onto_name, "...")) {
075bc852 PK	489	if (get_oid_mb(options.onto_name, &merge_base) < 0)
	490	die(_("'%s': need exactly one merge base"),
	491	options.onto_name);
	492	options.onto = lookup_commit_or_die(&merge_base,
	493	options.onto_name);
ac7f467f PK	494	} else {
	495	options.onto = peel_committish(options.onto_name);
	496	if (!options.onto)
	497	die(_("Does not point to a valid commit '%s'"),
	498	options.onto_name);
	499	}
	500
	501	/*
	502	* If the branch to rebase is given, that is the branch we will rebase
	503	* branch_name -- branch/commit being rebased, or
	504	* HEAD (already detached)
	505	* orig_head -- commit object name of tip of the branch before rebasing
	506	* head_name -- refs/heads/<that-branch> or "detached HEAD"
	507	*/
f28d40d3	508	if (argc > 0)
ac7f467f PK	509	die("TODO: handle switch_to");
	510	else {
	511	/* Do not need to switch branches, we are already on it. */
	512	options.head_name =
	513	xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
	514	&flags));
	515	if (!options.head_name)
	516	die(_("No such ref: %s"), "HEAD");
	517	if (flags & REF_ISSYMREF) {
	518	if (!skip_prefix(options.head_name,
	519	"refs/heads/", &branch_name))
	520	branch_name = options.head_name;
	521
	522	} else {
	523	options.head_name = xstrdup("detached HEAD");
	524	branch_name = "HEAD";
	525	}
	526	if (get_oid("HEAD", &options.orig_head))
	527	die(_("Could not resolve HEAD to a revision"));
	528	}
	529
e0333e5c PK	530	if (read_index(the_repository->index) < 0)
	531	die(_("could not read index"));
	532
	533	if (require_clean_work_tree("rebase",
	534	_("Please commit or stash them."), 1, 1)) {
	535	ret = 1;
	536	goto cleanup;
	537	}
	538
9a48a615 PK	539	/*
	540	* Now we are rebasing commits upstream..orig_head (or with --root,
	541	* everything leading up to orig_head) on top of onto.
	542	*/
	543
	544	/*
	545	* Check if we are already based on onto with linear history,
	546	* but this should be done only when upstream and onto are the same
	547	* and if this is not an interactive rebase.
	548	*/
	549	if (can_fast_forward(options.onto, &options.orig_head, &merge_base) &&
	550	!is_interactive(&options) && !options.restrict_revision &&
	551	!oidcmp(&options.upstream->object.oid, &options.onto->object.oid)) {
	552	int flag;
	553
	554	if (!(options.flags & REBASE_NO_QUIET))
	555	; /* be quiet */
	556	else if (!strcmp(branch_name, "HEAD") &&
	557	resolve_ref_unsafe("HEAD", 0, NULL, &flag))
	558	puts(_("HEAD is up to date, rebase forced."));
	559	else
	560	printf(_("Current branch %s is up to date, rebase "
	561	"forced.\n"), branch_name);
	562	}
	563
06e4775a PK	564	/* If a hook exists, give it a chance to interrupt*/
	565	if (!ok_to_skip_pre_rebase &&
	566	run_hook_le(NULL, "pre-rebase", options.upstream_arg,
	567	argc ? argv[0] : NULL, NULL))
	568	die(_("The pre-rebase hook refused to rebase."));
	569
bff014da PK	570	if (options.flags & REBASE_DIFFSTAT) {
	571	struct diff_options opts;
	572
	573	if (options.flags & REBASE_VERBOSE)
	574	printf(_("Changes from %s to %s:\n"),
	575	oid_to_hex(&merge_base),
	576	oid_to_hex(&options.onto->object.oid));
	577
	578	/* We want color (if set), but no pager */
	579	diff_setup(&opts);
	580	opts.stat_width = -1; /* use full terminal width */
	581	opts.stat_graph_width = -1; /* respect statGraphWidth config */
	582	opts.output_format \|=
	583	DIFF_FORMAT_SUMMARY \| DIFF_FORMAT_DIFFSTAT;
	584	opts.detect_rename = DIFF_DETECT_RENAME;
	585	diff_setup_done(&opts);
	586	diff_tree_oid(&merge_base, &options.onto->object.oid,
	587	"", &opts);
	588	diffcore_std(&opts);
	589	diff_flush(&opts);
	590	}
	591
	592	/* Detach HEAD and reset the tree */
	593	if (options.flags & REBASE_NO_QUIET)
	594	printf(_("First, rewinding head to replay your work on top of "
	595	"it...\n"));
	596
ac7f467f PK	597	strbuf_addf(&msg, "rebase: checkout %s", options.onto_name);
	598	if (reset_head(&options.onto->object.oid, "checkout", NULL, 1))
	599	die(_("Could not detach HEAD"));
	600	strbuf_release(&msg);
	601
	602	strbuf_addf(&revisions, "%s..%s",
	603	options.root ? oid_to_hex(&options.onto->object.oid) :
	604	(options.restrict_revision ?
	605	oid_to_hex(&options.restrict_revision->object.oid) :
	606	oid_to_hex(&options.upstream->object.oid)),
	607	oid_to_hex(&options.orig_head));
	608
	609	options.revisions = revisions.buf;
	610
	611	ret = !!run_specific_rebase(&options);
	612
e0333e5c	613	cleanup:
ac7f467f PK	614	strbuf_release(&revisions);
	615	free(options.head_name);
	616	return ret;
55071ea2	617	}