[thirdparty/git.git] / ll-merge.c

/*
 * Low level 3-way in-core file merge.
 *
 * Copyright (c) 2007 Junio C Hamano
 */

#include "cache.h"
#include "attr.h"
#include "xdiff-interface.h"
#include "run-command.h"
#include "ll-merge.h"

struct ll_merge_driver;

typedef int (*ll_merge_fn)(const struct ll_merge_driver *,
			   mmbuffer_t *result,
			   const char *path,
			   mmfile_t *orig, const char *orig_name,
			   mmfile_t *src1, const char *name1,
			   mmfile_t *src2, const char *name2,
			   const struct ll_merge_options *opts,
			   int marker_size);

struct ll_merge_driver {
	const char *name;
	const char *description;
	ll_merge_fn fn;
	const char *recursive;
	struct ll_merge_driver *next;
	char *cmdline;
};

/*
 * Built-in low-levels
 */
static int ll_binary_merge(const struct ll_merge_driver *drv_unused,
			   mmbuffer_t *result,
			   const char *path_unused,
			   mmfile_t *orig, const char *orig_name,
			   mmfile_t *src1, const char *name1,
			   mmfile_t *src2, const char *name2,
			   const struct ll_merge_options *opts,
			   int marker_size)
{
	mmfile_t *stolen;
	assert(opts);

	/*
	 * The tentative merge result is "ours" for the final round,
	 * or common ancestor for an internal merge.  Still return
	 * "conflicted merge" status.
	 */
	stolen = opts->virtual_ancestor ? orig : src1;

	result->ptr = stolen->ptr;
	result->size = stolen->size;
	stolen->ptr = NULL;
	return 1;
}

static int ll_xdl_merge(const struct ll_merge_driver *drv_unused,
			mmbuffer_t *result,
			const char *path,
			mmfile_t *orig, const char *orig_name,
			mmfile_t *src1, const char *name1,
			mmfile_t *src2, const char *name2,
			const struct ll_merge_options *opts,
			int marker_size)
{
	xmparam_t xmp;
	assert(opts);

	if (buffer_is_binary(orig->ptr, orig->size) ||
	    buffer_is_binary(src1->ptr, src1->size) ||
	    buffer_is_binary(src2->ptr, src2->size)) {
		warning("Cannot merge binary files: %s (%s vs. %s)\n",
			path, name1, name2);
		return ll_binary_merge(drv_unused, result,
				       path,
				       orig, orig_name,
				       src1, name1,
				       src2, name2,
				       opts, marker_size);
	}

	memset(&xmp, 0, sizeof(xmp));
	xmp.level = XDL_MERGE_ZEALOUS;
	xmp.favor = opts->variant;
	xmp.xpp.flags = opts->xdl_opts;
	if (git_xmerge_style >= 0)
		xmp.style = git_xmerge_style;
	if (marker_size > 0)
		xmp.marker_size = marker_size;
	xmp.ancestor = orig_name;
	xmp.file1 = name1;
	xmp.file2 = name2;
	return xdl_merge(orig, src1, src2, &xmp, result);
}

static int ll_union_merge(const struct ll_merge_driver *drv_unused,
			  mmbuffer_t *result,
			  const char *path_unused,
			  mmfile_t *orig, const char *orig_name,
			  mmfile_t *src1, const char *name1,
			  mmfile_t *src2, const char *name2,
			  const struct ll_merge_options *opts,
			  int marker_size)
{
	/* Use union favor */
	struct ll_merge_options o;
	assert(opts);
	o = *opts;
	o.variant = XDL_MERGE_FAVOR_UNION;
	return ll_xdl_merge(drv_unused, result, path_unused,
			    orig, NULL, src1, NULL, src2, NULL,
			    &o, marker_size);
}

#define LL_BINARY_MERGE 0
#define LL_TEXT_MERGE 1
#define LL_UNION_MERGE 2
static struct ll_merge_driver ll_merge_drv[] = {
	{ "binary", "built-in binary merge", ll_binary_merge },
	{ "text", "built-in 3-way text merge", ll_xdl_merge },
	{ "union", "built-in union merge", ll_union_merge },
};

static void create_temp(mmfile_t *src, char *path)
{
	int fd;

	strcpy(path, ".merge_file_XXXXXX");
	fd = xmkstemp(path);
	if (write_in_full(fd, src->ptr, src->size) != src->size)
		die_errno("unable to write temp-file");
	close(fd);
}

/*
 * User defined low-level merge driver support.
 */
static int ll_ext_merge(const struct ll_merge_driver *fn,
			mmbuffer_t *result,
			const char *path,
			mmfile_t *orig, const char *orig_name,
			mmfile_t *src1, const char *name1,
			mmfile_t *src2, const char *name2,
			const struct ll_merge_options *opts,
			int marker_size)
{
	char temp[4][50];
	struct strbuf cmd = STRBUF_INIT;
	struct strbuf_expand_dict_entry dict[5];
	const char *args[] = { NULL, NULL };
	int status, fd, i;
	struct stat st;
	assert(opts);

	dict[0].placeholder = "O"; dict[0].value = temp[0];
	dict[1].placeholder = "A"; dict[1].value = temp[1];
	dict[2].placeholder = "B"; dict[2].value = temp[2];
	dict[3].placeholder = "L"; dict[3].value = temp[3];
	dict[4].placeholder = NULL; dict[4].value = NULL;

	if (fn->cmdline == NULL)
		die("custom merge driver %s lacks command line.", fn->name);

	result->ptr = NULL;
	result->size = 0;
	create_temp(orig, temp[0]);
	create_temp(src1, temp[1]);
	create_temp(src2, temp[2]);
	sprintf(temp[3], "%d", marker_size);

	strbuf_expand(&cmd, fn->cmdline, strbuf_expand_dict_cb, &dict);

	args[0] = cmd.buf;
	status = run_command_v_opt(args, RUN_USING_SHELL);
	fd = open(temp[1], O_RDONLY);
	if (fd < 0)
		goto bad;
	if (fstat(fd, &st))
		goto close_bad;
	result->size = st.st_size;
	result->ptr = xmalloc(result->size + 1);
	if (read_in_full(fd, result->ptr, result->size) != result->size) {
		free(result->ptr);
		result->ptr = NULL;
		result->size = 0;
	}
 close_bad:
	close(fd);
 bad:
	for (i = 0; i < 3; i++)
		unlink_or_warn(temp[i]);
	strbuf_release(&cmd);
	return status;
}

/*
 * merge.default and merge.driver configuration items
 */
static struct ll_merge_driver *ll_user_merge, **ll_user_merge_tail;
static const char *default_ll_merge;

static int read_merge_config(const char *var, const char *value, void *cb)
{
	struct ll_merge_driver *fn;
	const char *ep, *name;
	int namelen;

	if (!strcmp(var, "merge.default")) {
		if (value)
			default_ll_merge = xstrdup(value);
		return 0;
	}

	/*
	 * We are not interested in anything but "merge.<name>.variable";
	 * especially, we do not want to look at variables such as
	 * "merge.summary", "merge.tool", and "merge.verbosity".
	 */
	if (prefixcmp(var, "merge.") || (ep = strrchr(var, '.')) == var + 5)
		return 0;

	/*
	 * Find existing one as we might be processing merge.<name>.var2
	 * after seeing merge.<name>.var1.
	 */
	name = var + 6;
	namelen = ep - name;
	for (fn = ll_user_merge; fn; fn = fn->next)
		if (!strncmp(fn->name, name, namelen) && !fn->name[namelen])
			break;
	if (!fn) {
		fn = xcalloc(1, sizeof(struct ll_merge_driver));
		fn->name = xmemdupz(name, namelen);
		fn->fn = ll_ext_merge;
		*ll_user_merge_tail = fn;
		ll_user_merge_tail = &(fn->next);
	}

	ep++;

	if (!strcmp("name", ep)) {
		if (!value)
			return error("%s: lacks value", var);
		fn->description = xstrdup(value);
		return 0;
	}

	if (!strcmp("driver", ep)) {
		if (!value)
			return error("%s: lacks value", var);
		/*
		 * merge.<name>.driver specifies the command line:
		 *
		 *	command-line
		 *
		 * The command-line will be interpolated with the following
		 * tokens and is given to the shell:
		 *
		 *    %O - temporary file name for the merge base.
		 *    %A - temporary file name for our version.
		 *    %B - temporary file name for the other branches' version.
		 *    %L - conflict marker length
		 *
		 * The external merge driver should write the results in the
		 * file named by %A, and signal that it has done with zero exit
		 * status.
		 */
		fn->cmdline = xstrdup(value);
		return 0;
	}

	if (!strcmp("recursive", ep)) {
		if (!value)
			return error("%s: lacks value", var);
		fn->recursive = xstrdup(value);
		return 0;
	}

	return 0;
}

static void initialize_ll_merge(void)
{
	if (ll_user_merge_tail)
		return;
	ll_user_merge_tail = &ll_user_merge;
	git_config(read_merge_config, NULL);
}

static const struct ll_merge_driver *find_ll_merge_driver(const char *merge_attr)
{
	struct ll_merge_driver *fn;
	const char *name;
	int i;

	initialize_ll_merge();

	if (ATTR_TRUE(merge_attr))
		return &ll_merge_drv[LL_TEXT_MERGE];
	else if (ATTR_FALSE(merge_attr))
		return &ll_merge_drv[LL_BINARY_MERGE];
	else if (ATTR_UNSET(merge_attr)) {
		if (!default_ll_merge)
			return &ll_merge_drv[LL_TEXT_MERGE];
		else
			name = default_ll_merge;
	}
	else
		name = merge_attr;

	for (fn = ll_user_merge; fn; fn = fn->next)
		if (!strcmp(fn->name, name))
			return fn;

	for (i = 0; i < ARRAY_SIZE(ll_merge_drv); i++)
		if (!strcmp(ll_merge_drv[i].name, name))
			return &ll_merge_drv[i];

	/* default to the 3-way */
	return &ll_merge_drv[LL_TEXT_MERGE];
}

static int git_path_check_merge(const char *path, struct git_attr_check check[2])
{
	if (!check[0].attr) {
		check[0].attr = git_attr("merge");
		check[1].attr = git_attr("conflict-marker-size");
	}
	return git_checkattr(path, 2, check);
}

static void normalize_file(mmfile_t *mm, const char *path)
{
	struct strbuf strbuf = STRBUF_INIT;
	if (renormalize_buffer(path, mm->ptr, mm->size, &strbuf)) {
		free(mm->ptr);
		mm->size = strbuf.len;
		mm->ptr = strbuf_detach(&strbuf, NULL);
	}
}

int ll_merge(mmbuffer_t *result_buf,
	     const char *path,
	     mmfile_t *ancestor, const char *ancestor_label,
	     mmfile_t *ours, const char *our_label,
	     mmfile_t *theirs, const char *their_label,
	     const struct ll_merge_options *opts)
{
	static struct git_attr_check check[2];
	static const struct ll_merge_options default_opts;
	const char *ll_driver_name = NULL;
	int marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
	const struct ll_merge_driver *driver;

	if (!opts)
		opts = &default_opts;

	if (opts->renormalize) {
		normalize_file(ancestor, path);
		normalize_file(ours, path);
		normalize_file(theirs, path);
	}
	if (!git_path_check_merge(path, check)) {
		ll_driver_name = check[0].value;
		if (check[1].value) {
			marker_size = atoi(check[1].value);
			if (marker_size <= 0)
				marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
		}
	}
	driver = find_ll_merge_driver(ll_driver_name);
	if (opts->virtual_ancestor && driver->recursive)
		driver = find_ll_merge_driver(driver->recursive);
	return driver->fn(driver, result_buf, path, ancestor, ancestor_label,
			  ours, our_label, theirs, their_label,
			  opts, marker_size);
}

int ll_merge_marker_size(const char *path)
{
	static struct git_attr_check check;
	int marker_size = DEFAULT_CONFLICT_MARKER_SIZE;

	if (!check.attr)
		check.attr = git_attr("conflict-marker-size");
	if (!git_checkattr(path, 1, &check) && check.value) {
		marker_size = atoi(check.value);
		if (marker_size <= 0)
			marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
	}
	return marker_size;
}
Commit	Line	Data
525ab639 JH	1	/*
	2	* Low level 3-way in-core file merge.
	3	*
	4	* Copyright (c) 2007 Junio C Hamano
	5	*/
	6
	7	#include "cache.h"
	8	#include "attr.h"
	9	#include "xdiff-interface.h"
	10	#include "run-command.h"
525ab639 JH	11	#include "ll-merge.h"
	12
	13	struct ll_merge_driver;
	14
	15	typedef int (ll_merge_fn)(const struct ll_merge_driver ,
	16	mmbuffer_t *result,
	17	const char *path,
f01de62e	18	mmfile_t orig, const char orig_name,
525ab639 JH	19	mmfile_t src1, const char name1,
525ab639 JH	20	mmfile_t src2, const char name2,
712516bc	21	const struct ll_merge_options *opts,
23a64c9e	22	int marker_size);
525ab639 JH	23
	24	struct ll_merge_driver {
	25	const char *name;
	26	const char *description;
	27	ll_merge_fn fn;
	28	const char *recursive;
	29	struct ll_merge_driver *next;
	30	char *cmdline;
	31	};
	32
	33	/*
	34	* Built-in low-levels
	35	*/
	36	static int ll_binary_merge(const struct ll_merge_driver *drv_unused,
	37	mmbuffer_t *result,
	38	const char *path_unused,
f01de62e	39	mmfile_t orig, const char orig_name,
525ab639 JH	40	mmfile_t src1, const char name1,
525ab639 JH	41	mmfile_t src2, const char name2,
712516bc JN	42	const struct ll_merge_options *opts,
712516bc JN	43	int marker_size)
525ab639	44	{
712516bc JN	45	mmfile_t *stolen;
	46	assert(opts);
	47
525ab639 JH	48	/*
	49	* The tentative merge result is "ours" for the final round,
	50	* or common ancestor for an internal merge. Still return
	51	* "conflicted merge" status.
	52	*/
712516bc	53	stolen = opts->virtual_ancestor ? orig : src1;
525ab639 JH	54
	55	result->ptr = stolen->ptr;
	56	result->size = stolen->size;
	57	stolen->ptr = NULL;
	58	return 1;
	59	}
	60
	61	static int ll_xdl_merge(const struct ll_merge_driver *drv_unused,
	62	mmbuffer_t *result,
606475f3	63	const char *path,
f01de62e	64	mmfile_t orig, const char orig_name,
525ab639 JH	65	mmfile_t src1, const char name1,
525ab639 JH	66	mmfile_t src2, const char name2,
712516bc JN	67	const struct ll_merge_options *opts,
712516bc JN	68	int marker_size)
525ab639	69	{
00f8f97d	70	xmparam_t xmp;
712516bc	71	assert(opts);
525ab639 JH	72
	73	if (buffer_is_binary(orig->ptr, orig->size) \|\|
	74	buffer_is_binary(src1->ptr, src1->size) \|\|
	75	buffer_is_binary(src2->ptr, src2->size)) {
606475f3 MR	76	warning("Cannot merge binary files: %s (%s vs. %s)\n",
606475f3 MR	77	path, name1, name2);
525ab639	78	return ll_binary_merge(drv_unused, result,
606475f3	79	path,
f01de62e JN	80	orig, orig_name,
f01de62e JN	81	src1, name1,
525ab639	82	src2, name2,
712516bc	83	opts, marker_size);
525ab639 JH	84	}
525ab639 JH	85
00f8f97d	86	memset(&xmp, 0, sizeof(xmp));
560119b9	87	xmp.level = XDL_MERGE_ZEALOUS;
712516bc	88	xmp.favor = opts->variant;
58a1ece4	89	xmp.xpp.flags = opts->xdl_opts;
c236bcd0	90	if (git_xmerge_style >= 0)
560119b9	91	xmp.style = git_xmerge_style;
23a64c9e JH	92	if (marker_size > 0)
23a64c9e JH	93	xmp.marker_size = marker_size;
f01de62e	94	xmp.ancestor = orig_name;
a4b5e91c JN	95	xmp.file1 = name1;
	96	xmp.file2 = name2;
	97	return xdl_merge(orig, src1, src2, &xmp, result);
525ab639 JH	98	}
	99
	100	static int ll_union_merge(const struct ll_merge_driver *drv_unused,
	101	mmbuffer_t *result,
	102	const char *path_unused,
f01de62e	103	mmfile_t orig, const char orig_name,
525ab639 JH	104	mmfile_t src1, const char name1,
525ab639 JH	105	mmfile_t src2, const char name2,
712516bc JN	106	const struct ll_merge_options *opts,
712516bc JN	107	int marker_size)
525ab639	108	{
cd1d61c4	109	/* Use union favor */
712516bc JN	110	struct ll_merge_options o;
	111	assert(opts);
	112	o = *opts;
	113	o.variant = XDL_MERGE_FAVOR_UNION;
cd1d61c4	114	return ll_xdl_merge(drv_unused, result, path_unused,
f01de62e	115	orig, NULL, src1, NULL, src2, NULL,
712516bc	116	&o, marker_size);
525ab639 JH	117	}
	118
	119	#define LL_BINARY_MERGE 0
	120	#define LL_TEXT_MERGE 1
	121	#define LL_UNION_MERGE 2
	122	static struct ll_merge_driver ll_merge_drv[] = {
	123	{ "binary", "built-in binary merge", ll_binary_merge },
	124	{ "text", "built-in 3-way text merge", ll_xdl_merge },
	125	{ "union", "built-in union merge", ll_union_merge },
	126	};
	127
	128	static void create_temp(mmfile_t src, char path)
	129	{
	130	int fd;
	131
	132	strcpy(path, ".merge_file_XXXXXX");
	133	fd = xmkstemp(path);
	134	if (write_in_full(fd, src->ptr, src->size) != src->size)
0721c314	135	die_errno("unable to write temp-file");
525ab639 JH	136	close(fd);
	137	}
	138
	139	/*
	140	* User defined low-level merge driver support.
	141	*/
	142	static int ll_ext_merge(const struct ll_merge_driver *fn,
	143	mmbuffer_t *result,
	144	const char *path,
f01de62e	145	mmfile_t orig, const char orig_name,
525ab639 JH	146	mmfile_t src1, const char name1,
525ab639 JH	147	mmfile_t src2, const char name2,
712516bc JN	148	const struct ll_merge_options *opts,
712516bc JN	149	int marker_size)
525ab639	150	{
23a64c9e	151	char temp[4][50];
ced621b2	152	struct strbuf cmd = STRBUF_INIT;
66dbfd55	153	struct strbuf_expand_dict_entry dict[5];
ac0ba18d	154	const char *args[] = { NULL, NULL };
525ab639 JH	155	int status, fd, i;
525ab639 JH	156	struct stat st;
712516bc	157	assert(opts);
525ab639	158
66dbfd55 GV	159	dict[0].placeholder = "O"; dict[0].value = temp[0];
	160	dict[1].placeholder = "A"; dict[1].value = temp[1];
	161	dict[2].placeholder = "B"; dict[2].value = temp[2];
	162	dict[3].placeholder = "L"; dict[3].value = temp[3];
	163	dict[4].placeholder = NULL; dict[4].value = NULL;
	164
525ab639 JH	165	if (fn->cmdline == NULL)
	166	die("custom merge driver %s lacks command line.", fn->name);
	167
	168	result->ptr = NULL;
	169	result->size = 0;
	170	create_temp(orig, temp[0]);
	171	create_temp(src1, temp[1]);
	172	create_temp(src2, temp[2]);
23a64c9e	173	sprintf(temp[3], "%d", marker_size);
525ab639	174
ced621b2	175	strbuf_expand(&cmd, fn->cmdline, strbuf_expand_dict_cb, &dict);
525ab639	176
ac0ba18d JK	177	args[0] = cmd.buf;
ac0ba18d JK	178	status = run_command_v_opt(args, RUN_USING_SHELL);
525ab639 JH	179	fd = open(temp[1], O_RDONLY);
	180	if (fd < 0)
	181	goto bad;
	182	if (fstat(fd, &st))
	183	goto close_bad;
	184	result->size = st.st_size;
	185	result->ptr = xmalloc(result->size + 1);
	186	if (read_in_full(fd, result->ptr, result->size) != result->size) {
	187	free(result->ptr);
	188	result->ptr = NULL;
	189	result->size = 0;
	190	}
	191	close_bad:
	192	close(fd);
	193	bad:
	194	for (i = 0; i < 3; i++)
691f1a28	195	unlink_or_warn(temp[i]);
ced621b2	196	strbuf_release(&cmd);
525ab639 JH	197	return status;
	198	}
	199
	200	/*
	201	* merge.default and merge.driver configuration items
	202	*/
	203	static struct ll_merge_driver ll_user_merge, *ll_user_merge_tail;
	204	static const char *default_ll_merge;
	205
ef90d6d4	206	static int read_merge_config(const char var, const char value, void *cb)
525ab639 JH	207	{
	208	struct ll_merge_driver *fn;
	209	const char ep, name;
	210	int namelen;
	211
	212	if (!strcmp(var, "merge.default")) {
	213	if (value)
90dce515	214	default_ll_merge = xstrdup(value);
525ab639 JH	215	return 0;
	216	}
	217
	218	/*
	219	* We are not interested in anything but "merge.<name>.variable";
	220	* especially, we do not want to look at variables such as
	221	* "merge.summary", "merge.tool", and "merge.verbosity".
	222	*/
	223	if (prefixcmp(var, "merge.") \|\| (ep = strrchr(var, '.')) == var + 5)
	224	return 0;
	225
	226	/*
	227	* Find existing one as we might be processing merge.<name>.var2
	228	* after seeing merge.<name>.var1.
	229	*/
	230	name = var + 6;
	231	namelen = ep - name;
	232	for (fn = ll_user_merge; fn; fn = fn->next)
	233	if (!strncmp(fn->name, name, namelen) && !fn->name[namelen])
	234	break;
	235	if (!fn) {
	236	fn = xcalloc(1, sizeof(struct ll_merge_driver));
	237	fn->name = xmemdupz(name, namelen);
	238	fn->fn = ll_ext_merge;
	239	*ll_user_merge_tail = fn;
	240	ll_user_merge_tail = &(fn->next);
	241	}
	242
	243	ep++;
	244
	245	if (!strcmp("name", ep)) {
	246	if (!value)
	247	return error("%s: lacks value", var);
90dce515	248	fn->description = xstrdup(value);
525ab639 JH	249	return 0;
	250	}
	251
	252	if (!strcmp("driver", ep)) {
	253	if (!value)
	254	return error("%s: lacks value", var);
	255	/*
	256	* merge.<name>.driver specifies the command line:
	257	*
	258	* command-line
	259	*
	260	* The command-line will be interpolated with the following
	261	* tokens and is given to the shell:
	262	*
	263	* %O - temporary file name for the merge base.
	264	* %A - temporary file name for our version.
	265	* %B - temporary file name for the other branches' version.
23a64c9e	266	* %L - conflict marker length
525ab639 JH	267	*
	268	* The external merge driver should write the results in the
	269	* file named by %A, and signal that it has done with zero exit
	270	* status.
	271	*/
90dce515	272	fn->cmdline = xstrdup(value);
525ab639 JH	273	return 0;
	274	}
	275
	276	if (!strcmp("recursive", ep)) {
	277	if (!value)
	278	return error("%s: lacks value", var);
90dce515	279	fn->recursive = xstrdup(value);
525ab639 JH	280	return 0;
	281	}
	282
	283	return 0;
	284	}
	285
	286	static void initialize_ll_merge(void)
	287	{
	288	if (ll_user_merge_tail)
	289	return;
	290	ll_user_merge_tail = &ll_user_merge;
ef90d6d4	291	git_config(read_merge_config, NULL);
525ab639 JH	292	}
	293
	294	static const struct ll_merge_driver find_ll_merge_driver(const char merge_attr)
	295	{
	296	struct ll_merge_driver *fn;
	297	const char *name;
	298	int i;
	299
	300	initialize_ll_merge();
	301
	302	if (ATTR_TRUE(merge_attr))
	303	return &ll_merge_drv[LL_TEXT_MERGE];
	304	else if (ATTR_FALSE(merge_attr))
	305	return &ll_merge_drv[LL_BINARY_MERGE];
	306	else if (ATTR_UNSET(merge_attr)) {
	307	if (!default_ll_merge)
	308	return &ll_merge_drv[LL_TEXT_MERGE];
	309	else
	310	name = default_ll_merge;
	311	}
	312	else
	313	name = merge_attr;
	314
	315	for (fn = ll_user_merge; fn; fn = fn->next)
	316	if (!strcmp(fn->name, name))
	317	return fn;
	318
	319	for (i = 0; i < ARRAY_SIZE(ll_merge_drv); i++)
	320	if (!strcmp(ll_merge_drv[i].name, name))
	321	return &ll_merge_drv[i];
	322
	323	/* default to the 3-way */
	324	return &ll_merge_drv[LL_TEXT_MERGE];
	325	}
	326
23a64c9e	327	static int git_path_check_merge(const char *path, struct git_attr_check check[2])
525ab639	328	{
23a64c9e JH	329	if (!check[0].attr) {
	330	check[0].attr = git_attr("merge");
	331	check[1].attr = git_attr("conflict-marker-size");
	332	}
	333	return git_checkattr(path, 2, check);
525ab639 JH	334	}
525ab639 JH	335
f217f0e8 EB	336	static void normalize_file(mmfile_t mm, const char path)
	337	{
	338	struct strbuf strbuf = STRBUF_INIT;
	339	if (renormalize_buffer(path, mm->ptr, mm->size, &strbuf)) {
	340	free(mm->ptr);
	341	mm->size = strbuf.len;
	342	mm->ptr = strbuf_detach(&strbuf, NULL);
	343	}
	344	}
	345
525ab639 JH	346	int ll_merge(mmbuffer_t *result_buf,
525ab639 JH	347	const char *path,
f01de62e	348	mmfile_t ancestor, const char ancestor_label,
525ab639 JH	349	mmfile_t ours, const char our_label,
525ab639 JH	350	mmfile_t theirs, const char their_label,
712516bc	351	const struct ll_merge_options *opts)
525ab639	352	{
23a64c9e	353	static struct git_attr_check check[2];
4fb40c2b	354	static const struct ll_merge_options default_opts;
23a64c9e JH	355	const char *ll_driver_name = NULL;
23a64c9e JH	356	int marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
525ab639 JH	357	const struct ll_merge_driver *driver;
525ab639 JH	358
4fb40c2b JN	359	if (!opts)
4fb40c2b JN	360	opts = &default_opts;
712516bc JN	361
712516bc JN	362	if (opts->renormalize) {
f217f0e8 EB	363	normalize_file(ancestor, path);
	364	normalize_file(ours, path);
	365	normalize_file(theirs, path);
	366	}
23a64c9e JH	367	if (!git_path_check_merge(path, check)) {
	368	ll_driver_name = check[0].value;
	369	if (check[1].value) {
	370	marker_size = atoi(check[1].value);
	371	if (marker_size <= 0)
	372	marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
	373	}
	374	}
525ab639	375	driver = find_ll_merge_driver(ll_driver_name);
712516bc	376	if (opts->virtual_ancestor && driver->recursive)
525ab639	377	driver = find_ll_merge_driver(driver->recursive);
f01de62e	378	return driver->fn(driver, result_buf, path, ancestor, ancestor_label,
23a64c9e	379	ours, our_label, theirs, their_label,
712516bc	380	opts, marker_size);
525ab639	381	}
8588567c JH	382
	383	int ll_merge_marker_size(const char *path)
	384	{
	385	static struct git_attr_check check;
	386	int marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
	387
	388	if (!check.attr)
	389	check.attr = git_attr("conflict-marker-size");
	390	if (!git_checkattr(path, 1, &check) && check.value) {
	391	marker_size = atoi(check.value);
	392	if (marker_size <= 0)
	393	marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
	394	}
	395	return marker_size;
525ab639	396	}