[thirdparty/git.git] / builtin-reset.c

/*
 * "git reset" builtin command
 *
 * Copyright (c) 2007 Carlos Rica
 *
 * Based on git-reset.sh, which is
 *
 * Copyright (c) 2005, 2006 Linus Torvalds and Junio C Hamano
 */
#include "cache.h"
#include "tag.h"
#include "object.h"
#include "commit.h"
#include "run-command.h"
#include "refs.h"
#include "diff.h"
#include "diffcore.h"
#include "tree.h"

static const char builtin_reset_usage[] =
"git-reset [--mixed | --soft | --hard] [-q] [<commit-ish>] [ [--] <paths>...]";

static char *args_to_str(const char **argv)
{
	char *buf = NULL;
	unsigned long len, space = 0, nr = 0;

	for (; *argv; argv++) {
		len = strlen(*argv);
		ALLOC_GROW(buf, nr + 1 + len, space);
		if (nr)
			buf[nr++] = ' ';
		memcpy(buf + nr, *argv, len);
		nr += len;
	}
	ALLOC_GROW(buf, nr + 1, space);
	buf[nr] = '\0';

	return buf;
}

static inline int is_merge(void)
{
	return !access(git_path("MERGE_HEAD"), F_OK);
}

static int unmerged_files(void)
{
	int i;
	read_cache();
	for (i = 0; i < active_nr; i++) {
		struct cache_entry *ce = active_cache[i];
		if (ce_stage(ce))
			return 1;
	}
	return 0;
}

static int reset_index_file(const unsigned char *sha1, int is_hard_reset)
{
	int i = 0;
	const char *args[6];

	args[i++] = "read-tree";
	args[i++] = "-v";
	args[i++] = "--reset";
	if (is_hard_reset)
		args[i++] = "-u";
	args[i++] = sha1_to_hex(sha1);
	args[i] = NULL;

	return run_command_v_opt(args, RUN_GIT_CMD);
}

static void print_new_head_line(struct commit *commit)
{
	const char *hex, *dots = "...", *body;

	hex = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
	if (!hex) {
		hex = sha1_to_hex(commit->object.sha1);
		dots = "";
	}
	printf("HEAD is now at %s%s", hex, dots);
	body = strstr(commit->buffer, "\n\n");
	if (body) {
		const char *eol;
		size_t len;
		body += 2;
		eol = strchr(body, '\n');
		len = eol ? eol - body : strlen(body);
		printf(" %.*s\n", (int) len, body);
	}
	else
		printf("\n");
}

static int update_index_refresh(int fd, struct lock_file *index_lock)
{
	int result;

	if (!index_lock) {
		index_lock = xcalloc(1, sizeof(struct lock_file));
		fd = hold_locked_index(index_lock, 1);
	}

	if (read_cache() < 0)
		return error("Could not read index");
	result = refresh_cache(0) ? 1 : 0;
	if (write_cache(fd, active_cache, active_nr) ||
			close(fd) ||
			commit_locked_index(index_lock))
		return error ("Could not refresh index");
	return result;
}

static void update_index_from_diff(struct diff_queue_struct *q,
		struct diff_options *opt, void *data)
{
	int i;
	int *discard_flag = data;

	/* do_diff_cache() mangled the index */
	discard_cache();
	*discard_flag = 1;
	read_cache();

	for (i = 0; i < q->nr; i++) {
		struct diff_filespec *one = q->queue[i]->one;
		if (one->mode) {
			struct cache_entry *ce;
			ce = make_cache_entry(one->mode, one->sha1, one->path,
				0, 0);
			add_cache_entry(ce, ADD_CACHE_OK_TO_ADD |
				ADD_CACHE_OK_TO_REPLACE);
		} else
			remove_file_from_cache(one->path);
	}
}

static int read_from_tree(const char *prefix, const char **argv,
		unsigned char *tree_sha1)
{
	struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
	int index_fd, index_was_discarded = 0;
	struct diff_options opt;

	memset(&opt, 0, sizeof(opt));
	diff_tree_setup_paths(get_pathspec(prefix, (const char **)argv), &opt);
	opt.output_format = DIFF_FORMAT_CALLBACK;
	opt.format_callback = update_index_from_diff;
	opt.format_callback_data = &index_was_discarded;

	index_fd = hold_locked_index(lock, 1);
	index_was_discarded = 0;
	read_cache();
	if (do_diff_cache(tree_sha1, &opt))
		return 1;
	diffcore_std(&opt);
	diff_flush(&opt);

	if (!index_was_discarded)
		/* The index is still clobbered from do_diff_cache() */
		discard_cache();
	return update_index_refresh(index_fd, lock);
}

static void prepend_reflog_action(const char *action, char *buf, size_t size)
{
	const char *sep = ": ";
	const char *rla = getenv("GIT_REFLOG_ACTION");
	if (!rla)
		rla = sep = "";
	if (snprintf(buf, size, "%s%s%s", rla, sep, action) >= size)
		warning("Reflog action message too long: %.*s...", 50, buf);
}

enum reset_type { MIXED, SOFT, HARD, NONE };
static const char *reset_type_names[] = { "mixed", "soft", "hard", NULL };

int cmd_reset(int argc, const char **argv, const char *prefix)
{
	int i = 1, reset_type = NONE, update_ref_status = 0, quiet = 0;
	const char *rev = "HEAD";
	unsigned char sha1[20], *orig = NULL, sha1_orig[20],
				*old_orig = NULL, sha1_old_orig[20];
	struct commit *commit;
	char *reflog_action, msg[1024];

	git_config(git_default_config);

	reflog_action = args_to_str(argv);
	setenv("GIT_REFLOG_ACTION", reflog_action, 0);

	while (i < argc) {
		if (!strcmp(argv[i], "--mixed")) {
			reset_type = MIXED;
			i++;
		}
		else if (!strcmp(argv[i], "--soft")) {
			reset_type = SOFT;
			i++;
		}
		else if (!strcmp(argv[i], "--hard")) {
			reset_type = HARD;
			i++;
		}
		else if (!strcmp(argv[i], "-q")) {
			quiet = 1;
			i++;
		}
		else
			break;
	}

	if (i < argc && argv[i][0] != '-')
		rev = argv[i++];

	if (get_sha1(rev, sha1))
		die("Failed to resolve '%s' as a valid ref.", rev);

	commit = lookup_commit_reference(sha1);
	if (!commit)
		die("Could not parse object '%s'.", rev);
	hashcpy(sha1, commit->object.sha1);

	if (i < argc && !strcmp(argv[i], "--"))
		i++;
	else if (i < argc && argv[i][0] == '-')
		usage(builtin_reset_usage);

	/* git reset tree [--] paths... can be used to
	 * load chosen paths from the tree into the index without
	 * affecting the working tree nor HEAD. */
	if (i < argc) {
		if (reset_type == MIXED)
			warning("--mixed option is deprecated with paths.");
		else if (reset_type != NONE)
			die("Cannot do %s reset with paths.",
					reset_type_names[reset_type]);
		return read_from_tree(prefix, argv + i, sha1);
	}
	if (reset_type == NONE)
		reset_type = MIXED; /* by default */

	/* Soft reset does not touch the index file nor the working tree
	 * at all, but requires them in a good order.  Other resets reset
	 * the index file to the tree object we are switching to. */
	if (reset_type == SOFT) {
		if (is_merge() || unmerged_files())
			die("Cannot do a soft reset in the middle of a merge.");
	}
	else if (reset_index_file(sha1, (reset_type == HARD)))
		die("Could not reset index file to revision '%s'.", rev);

	/* Any resets update HEAD to the head being switched to,
	 * saving the previous head in ORIG_HEAD before. */
	if (!get_sha1("ORIG_HEAD", sha1_old_orig))
		old_orig = sha1_old_orig;
	if (!get_sha1("HEAD", sha1_orig)) {
		orig = sha1_orig;
		prepend_reflog_action("updating ORIG_HEAD", msg, sizeof(msg));
		update_ref(msg, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
	}
	else if (old_orig)
		delete_ref("ORIG_HEAD", old_orig);
	prepend_reflog_action("updating HEAD", msg, sizeof(msg));
	update_ref_status = update_ref(msg, "HEAD", sha1, orig, 0, MSG_ON_ERR);

	switch (reset_type) {
	case HARD:
		if (!update_ref_status && !quiet)
			print_new_head_line(commit);
		break;
	case SOFT: /* Nothing else to do. */
		break;
	case MIXED: /* Report what has not been updated. */
		update_index_refresh(0, NULL);
		break;
	}

	unlink(git_path("MERGE_HEAD"));
	unlink(git_path("rr-cache/MERGE_RR"));
	unlink(git_path("MERGE_MSG"));
	unlink(git_path("SQUASH_MSG"));

	free(reflog_action);

	return update_ref_status;
}
Commit	Line	Data
0e5a7faa CR	1	/*
	2	* "git reset" builtin command
	3	*
	4	* Copyright (c) 2007 Carlos Rica
	5	*
	6	* Based on git-reset.sh, which is
	7	*
	8	* Copyright (c) 2005, 2006 Linus Torvalds and Junio C Hamano
	9	*/
	10	#include "cache.h"
	11	#include "tag.h"
	12	#include "object.h"
	13	#include "commit.h"
	14	#include "run-command.h"
	15	#include "refs.h"
	16	#include "diff.h"
	17	#include "diffcore.h"
	18	#include "tree.h"
	19
	20	static const char builtin_reset_usage[] =
521b53e5	21	"git-reset [--mixed \| --soft \| --hard] [-q] [<commit-ish>] [ [--] <paths>...]";
0e5a7faa CR	22
	23	static char args_to_str(const char *argv)
	24	{
	25	char *buf = NULL;
	26	unsigned long len, space = 0, nr = 0;
	27
	28	for (; *argv; argv++) {
	29	len = strlen(*argv);
	30	ALLOC_GROW(buf, nr + 1 + len, space);
	31	if (nr)
	32	buf[nr++] = ' ';
	33	memcpy(buf + nr, *argv, len);
	34	nr += len;
	35	}
	36	ALLOC_GROW(buf, nr + 1, space);
	37	buf[nr] = '\0';
	38
	39	return buf;
	40	}
	41
	42	static inline int is_merge(void)
	43	{
	44	return !access(git_path("MERGE_HEAD"), F_OK);
	45	}
	46
	47	static int unmerged_files(void)
	48	{
cdf4a751 JS	49	int i;
	50	read_cache();
	51	for (i = 0; i < active_nr; i++) {
	52	struct cache_entry *ce = active_cache[i];
	53	if (ce_stage(ce))
	54	return 1;
	55	}
	56	return 0;
0e5a7faa CR	57	}
	58
	59	static int reset_index_file(const unsigned char *sha1, int is_hard_reset)
	60	{
	61	int i = 0;
	62	const char *args[6];
	63
	64	args[i++] = "read-tree";
	65	args[i++] = "-v";
	66	args[i++] = "--reset";
	67	if (is_hard_reset)
	68	args[i++] = "-u";
	69	args[i++] = sha1_to_hex(sha1);
	70	args[i] = NULL;
	71
	72	return run_command_v_opt(args, RUN_GIT_CMD);
	73	}
	74
	75	static void print_new_head_line(struct commit *commit)
	76	{
	77	const char hex, dots = "...", *body;
	78
	79	hex = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
	80	if (!hex) {
	81	hex = sha1_to_hex(commit->object.sha1);
	82	dots = "";
	83	}
	84	printf("HEAD is now at %s%s", hex, dots);
	85	body = strstr(commit->buffer, "\n\n");
	86	if (body) {
	87	const char *eol;
	88	size_t len;
	89	body += 2;
	90	eol = strchr(body, '\n');
	91	len = eol ? eol - body : strlen(body);
	92	printf(" %.*s\n", (int) len, body);
	93	}
	94	else
	95	printf("\n");
	96	}
	97
620a6cd4	98	static int update_index_refresh(int fd, struct lock_file *index_lock)
0e5a7faa	99	{
620a6cd4	100	int result;
0e5a7faa	101
620a6cd4 JS	102	if (!index_lock) {
	103	index_lock = xcalloc(1, sizeof(struct lock_file));
	104	fd = hold_locked_index(index_lock, 1);
	105	}
0e5a7faa	106
620a6cd4 JS	107	if (read_cache() < 0)
	108	return error("Could not read index");
	109	result = refresh_cache(0) ? 1 : 0;
	110	if (write_cache(fd, active_cache, active_nr) \|\|
	111	close(fd) \|\|
	112	commit_locked_index(index_lock))
	113	return error ("Could not refresh index");
	114	return result;
	115	}
2e7a9785	116
0e5a7faa CR	117	static void update_index_from_diff(struct diff_queue_struct *q,
	118	struct diff_options opt, void data)
	119	{
	120	int i;
620a6cd4	121	int *discard_flag = data;
0e5a7faa CR	122
	123	/* do_diff_cache() mangled the index */
	124	discard_cache();
620a6cd4	125	*discard_flag = 1;
0e5a7faa CR	126	read_cache();
	127
	128	for (i = 0; i < q->nr; i++) {
	129	struct diff_filespec *one = q->queue[i]->one;
	130	if (one->mode) {
	131	struct cache_entry *ce;
	132	ce = make_cache_entry(one->mode, one->sha1, one->path,
	133	0, 0);
	134	add_cache_entry(ce, ADD_CACHE_OK_TO_ADD \|
	135	ADD_CACHE_OK_TO_REPLACE);
	136	} else
	137	remove_file_from_cache(one->path);
	138	}
	139	}
	140
	141	static int read_from_tree(const char prefix, const char *argv,
	142	unsigned char *tree_sha1)
	143	{
620a6cd4 JS	144	struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
620a6cd4 JS	145	int index_fd, index_was_discarded = 0;
0e5a7faa CR	146	struct diff_options opt;
	147
	148	memset(&opt, 0, sizeof(opt));
	149	diff_tree_setup_paths(get_pathspec(prefix, (const char **)argv), &opt);
	150	opt.output_format = DIFF_FORMAT_CALLBACK;
	151	opt.format_callback = update_index_from_diff;
620a6cd4	152	opt.format_callback_data = &index_was_discarded;
0e5a7faa	153
620a6cd4 JS	154	index_fd = hold_locked_index(lock, 1);
620a6cd4 JS	155	index_was_discarded = 0;
0e5a7faa CR	156	read_cache();
	157	if (do_diff_cache(tree_sha1, &opt))
	158	return 1;
	159	diffcore_std(&opt);
	160	diff_flush(&opt);
2e7a9785	161
620a6cd4 JS	162	if (!index_was_discarded)
	163	/* The index is still clobbered from do_diff_cache() */
	164	discard_cache();
	165	return update_index_refresh(index_fd, lock);
0e5a7faa CR	166	}
	167
	168	static void prepend_reflog_action(const char action, char buf, size_t size)
	169	{
	170	const char *sep = ": ";
	171	const char *rla = getenv("GIT_REFLOG_ACTION");
	172	if (!rla)
	173	rla = sep = "";
	174	if (snprintf(buf, size, "%s%s%s", rla, sep, action) >= size)
	175	warning("Reflog action message too long: %.*s...", 50, buf);
	176	}
	177
	178	enum reset_type { MIXED, SOFT, HARD, NONE };
538dfe73	179	static const char *reset_type_names[] = { "mixed", "soft", "hard", NULL };
0e5a7faa CR	180
	181	int cmd_reset(int argc, const char *argv, const char prefix)
	182	{
521b53e5	183	int i = 1, reset_type = NONE, update_ref_status = 0, quiet = 0;
0e5a7faa CR	184	const char *rev = "HEAD";
	185	unsigned char sha1[20], *orig = NULL, sha1_orig[20],
	186	*old_orig = NULL, sha1_old_orig[20];
	187	struct commit *commit;
	188	char *reflog_action, msg[1024];
	189
	190	git_config(git_default_config);
	191
	192	reflog_action = args_to_str(argv);
	193	setenv("GIT_REFLOG_ACTION", reflog_action, 0);
	194
521b53e5	195	while (i < argc) {
0e5a7faa CR	196	if (!strcmp(argv[i], "--mixed")) {
	197	reset_type = MIXED;
	198	i++;
	199	}
	200	else if (!strcmp(argv[i], "--soft")) {
	201	reset_type = SOFT;
	202	i++;
	203	}
	204	else if (!strcmp(argv[i], "--hard")) {
	205	reset_type = HARD;
	206	i++;
	207	}
521b53e5 GP	208	else if (!strcmp(argv[i], "-q")) {
	209	quiet = 1;
	210	i++;
	211	}
	212	else
	213	break;
0e5a7faa CR	214	}
	215
	216	if (i < argc && argv[i][0] != '-')
	217	rev = argv[i++];
	218
	219	if (get_sha1(rev, sha1))
	220	die("Failed to resolve '%s' as a valid ref.", rev);
	221
	222	commit = lookup_commit_reference(sha1);
	223	if (!commit)
	224	die("Could not parse object '%s'.", rev);
	225	hashcpy(sha1, commit->object.sha1);
	226
	227	if (i < argc && !strcmp(argv[i], "--"))
	228	i++;
	229	else if (i < argc && argv[i][0] == '-')
	230	usage(builtin_reset_usage);
	231
	232	/* git reset tree [--] paths... can be used to
	233	* load chosen paths from the tree into the index without
	234	* affecting the working tree nor HEAD. */
	235	if (i < argc) {
	236	if (reset_type == MIXED)
	237	warning("--mixed option is deprecated with paths.");
	238	else if (reset_type != NONE)
	239	die("Cannot do %s reset with paths.",
	240	reset_type_names[reset_type]);
620a6cd4	241	return read_from_tree(prefix, argv + i, sha1);
0e5a7faa CR	242	}
	243	if (reset_type == NONE)
	244	reset_type = MIXED; /* by default */
	245
	246	/* Soft reset does not touch the index file nor the working tree
	247	* at all, but requires them in a good order. Other resets reset
	248	* the index file to the tree object we are switching to. */
	249	if (reset_type == SOFT) {
	250	if (is_merge() \|\| unmerged_files())
	251	die("Cannot do a soft reset in the middle of a merge.");
	252	}
	253	else if (reset_index_file(sha1, (reset_type == HARD)))
	254	die("Could not reset index file to revision '%s'.", rev);
	255
	256	/* Any resets update HEAD to the head being switched to,
	257	* saving the previous head in ORIG_HEAD before. */
	258	if (!get_sha1("ORIG_HEAD", sha1_old_orig))
	259	old_orig = sha1_old_orig;
	260	if (!get_sha1("HEAD", sha1_orig)) {
	261	orig = sha1_orig;
	262	prepend_reflog_action("updating ORIG_HEAD", msg, sizeof(msg));
	263	update_ref(msg, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
	264	}
	265	else if (old_orig)
	266	delete_ref("ORIG_HEAD", old_orig);
	267	prepend_reflog_action("updating HEAD", msg, sizeof(msg));
	268	update_ref_status = update_ref(msg, "HEAD", sha1, orig, 0, MSG_ON_ERR);
	269
	270	switch (reset_type) {
	271	case HARD:
521b53e5	272	if (!update_ref_status && !quiet)
0e5a7faa CR	273	print_new_head_line(commit);
	274	break;
	275	case SOFT: /* Nothing else to do. */
	276	break;
	277	case MIXED: /* Report what has not been updated. */
620a6cd4	278	update_index_refresh(0, NULL);
0e5a7faa CR	279	break;
	280	}
	281
	282	unlink(git_path("MERGE_HEAD"));
	283	unlink(git_path("rr-cache/MERGE_RR"));
	284	unlink(git_path("MERGE_MSG"));
	285	unlink(git_path("SQUASH_MSG"));
	286
	287	free(reflog_action);
	288
	289	return update_ref_status;
	290	}