[thirdparty/git.git] / tree-diff.c

/*
 * Helper functions for tree diff generation
 */
#include "cache.h"
#include "diff.h"
#include "diffcore.h"
#include "tree.h"

static void show_entry(struct diff_options *opt, const char *prefix,
		       struct tree_desc *desc, struct strbuf *base);

static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2,
			      struct strbuf *base, struct diff_options *opt)
{
	unsigned mode1, mode2;
	const char *path1, *path2;
	const unsigned char *sha1, *sha2;
	int cmp, pathlen1, pathlen2;
	int old_baselen = base->len;
	int retval = 0;

	sha1 = tree_entry_extract(t1, &path1, &mode1);
	sha2 = tree_entry_extract(t2, &path2, &mode2);

	pathlen1 = tree_entry_len(path1, sha1);
	pathlen2 = tree_entry_len(path2, sha2);
	cmp = base_name_compare(path1, pathlen1, mode1, path2, pathlen2, mode2);
	if (cmp < 0) {
		show_entry(opt, "-", t1, base);
		return -1;
	}
	if (cmp > 0) {
		show_entry(opt, "+", t2, base);
		return 1;
	}
	if (!DIFF_OPT_TST(opt, FIND_COPIES_HARDER) && !hashcmp(sha1, sha2) && mode1 == mode2)
		return 0;

	/*
	 * If the filemode has changed to/from a directory from/to a regular
	 * file, we need to consider it a remove and an add.
	 */
	if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
		show_entry(opt, "-", t1, base);
		show_entry(opt, "+", t2, base);
		return 0;
	}

	strbuf_add(base, path1, pathlen1);
	if (DIFF_OPT_TST(opt, RECURSIVE) && S_ISDIR(mode1)) {
		if (DIFF_OPT_TST(opt, TREE_IN_RECURSIVE)) {
			opt->change(opt, mode1, mode2,
				    sha1, sha2, base->buf, 0, 0);
		}
		strbuf_addch(base, '/');
		retval = diff_tree_sha1(sha1, sha2, base->buf, opt);
	} else {
		opt->change(opt, mode1, mode2, sha1, sha2, base->buf, 0, 0);
	}
	strbuf_setlen(base, old_baselen);
	return 0;
}

/* A whole sub-tree went away or appeared */
static void show_tree(struct diff_options *opt, const char *prefix,
		      struct tree_desc *desc, struct strbuf *base)
{
	int all_interesting = 0;
	while (desc->size) {
		int show;

		if (all_interesting)
			show = 1;
		else {
			show = tree_entry_interesting(&desc->entry, base, 0,
						      &opt->pathspec);
			if (show == 2)
				all_interesting = 1;
		}
		if (show < 0)
			break;
		if (show)
			show_entry(opt, prefix, desc, base);
		update_tree_entry(desc);
	}
}

/* A file entry went away or appeared */
static void show_entry(struct diff_options *opt, const char *prefix,
		       struct tree_desc *desc, struct strbuf *base)
{
	unsigned mode;
	const char *path;
	const unsigned char *sha1 = tree_entry_extract(desc, &path, &mode);
	int pathlen = tree_entry_len(path, sha1);
	int old_baselen = base->len;

	strbuf_add(base, path, pathlen);
	if (DIFF_OPT_TST(opt, RECURSIVE) && S_ISDIR(mode)) {
		enum object_type type;
		struct tree_desc inner;
		void *tree;
		unsigned long size;

		tree = read_sha1_file(sha1, &type, &size);
		if (!tree || type != OBJ_TREE)
			die("corrupt tree sha %s", sha1_to_hex(sha1));

		if (DIFF_OPT_TST(opt, TREE_IN_RECURSIVE))
			opt->add_remove(opt, *prefix, mode, sha1, base->buf, 0);

		strbuf_addch(base, '/');

		init_tree_desc(&inner, tree, size);
		show_tree(opt, prefix, &inner, base);
		free(tree);
	} else
		opt->add_remove(opt, prefix[0], mode, sha1, base->buf, 0);

	strbuf_setlen(base, old_baselen);
}

static void skip_uninteresting(struct tree_desc *t, struct strbuf *base,
			       struct diff_options *opt, int *all_interesting)
{
	while (t->size) {
		int show = tree_entry_interesting(&t->entry, base, 0, &opt->pathspec);
		if (show == 2)
			*all_interesting = 1;
		if (!show) {
			update_tree_entry(t);
			continue;
		}
		/* Skip it all? */
		if (show < 0)
			t->size = 0;
		return;
	}
}

int diff_tree(struct tree_desc *t1, struct tree_desc *t2,
	      const char *base_str, struct diff_options *opt)
{
	struct strbuf base;
	int baselen = strlen(base_str);
	int all_t1_interesting = 0;
	int all_t2_interesting = 0;

	/* Enable recursion indefinitely */
	opt->pathspec.recursive = DIFF_OPT_TST(opt, RECURSIVE);
	opt->pathspec.max_depth = -1;

	strbuf_init(&base, PATH_MAX);
	strbuf_add(&base, base_str, baselen);

	for (;;) {
		if (DIFF_OPT_TST(opt, QUICK) &&
		    DIFF_OPT_TST(opt, HAS_CHANGES))
			break;
		if (opt->pathspec.nr) {
			if (!all_t1_interesting)
				skip_uninteresting(t1, &base, opt, &all_t1_interesting);
			if (!all_t2_interesting)
				skip_uninteresting(t2, &base, opt, &all_t2_interesting);
		}
		if (!t1->size) {
			if (!t2->size)
				break;
			show_entry(opt, "+", t2, &base);
			update_tree_entry(t2);
			continue;
		}
		if (!t2->size) {
			show_entry(opt, "-", t1, &base);
			update_tree_entry(t1);
			continue;
		}
		switch (compare_tree_entry(t1, t2, &base, opt)) {
		case -1:
			update_tree_entry(t1);
			continue;
		case 0:
			update_tree_entry(t1);
			/* Fallthrough */
		case 1:
			update_tree_entry(t2);
			continue;
		}
		die("git diff-tree: internal error");
	}

	strbuf_release(&base);
	return 0;
}

/*
 * Does it look like the resulting diff might be due to a rename?
 *  - single entry
 *  - not a valid previous file
 */
static inline int diff_might_be_rename(void)
{
	return diff_queued_diff.nr == 1 &&
		!DIFF_FILE_VALID(diff_queued_diff.queue[0]->one);
}

static void try_to_follow_renames(struct tree_desc *t1, struct tree_desc *t2, const char *base, struct diff_options *opt)
{
	struct diff_options diff_opts;
	struct diff_queue_struct *q = &diff_queued_diff;
	struct diff_filepair *choice;
	const char *paths[1];
	int i;

	/* Remove the file creation entry from the diff queue, and remember it */
	choice = q->queue[0];
	q->nr = 0;

	diff_setup(&diff_opts);
	DIFF_OPT_SET(&diff_opts, RECURSIVE);
	DIFF_OPT_SET(&diff_opts, FIND_COPIES_HARDER);
	diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
	diff_opts.single_follow = opt->pathspec.raw[0];
	diff_opts.break_opt = opt->break_opt;
	paths[0] = NULL;
	diff_tree_setup_paths(paths, &diff_opts);
	if (diff_setup_done(&diff_opts) < 0)
		die("unable to set up diff options to follow renames");
	diff_tree(t1, t2, base, &diff_opts);
	diffcore_std(&diff_opts);
	diff_tree_release_paths(&diff_opts);

	/* Go through the new set of filepairing, and see if we find a more interesting one */
	opt->found_follow = 0;
	for (i = 0; i < q->nr; i++) {
		struct diff_filepair *p = q->queue[i];

		/*
		 * Found a source? Not only do we use that for the new
		 * diff_queued_diff, we will also use that as the path in
		 * the future!
		 */
		if ((p->status == 'R' || p->status == 'C') &&
		    !strcmp(p->two->path, opt->pathspec.raw[0])) {
			/* Switch the file-pairs around */
			q->queue[i] = choice;
			choice = p;

			/* Update the path we use from now on.. */
			diff_tree_release_paths(opt);
			opt->pathspec.raw[0] = xstrdup(p->one->path);
			diff_tree_setup_paths(opt->pathspec.raw, opt);

			/*
			 * The caller expects us to return a set of vanilla
			 * filepairs to let a later call to diffcore_std()
			 * it makes to sort the renames out (among other
			 * things), but we already have found renames
			 * ourselves; signal diffcore_std() not to muck with
			 * rename information.
			 */
			opt->found_follow = 1;
			break;
		}
	}

	/*
	 * Then, discard all the non-relevant file pairs...
	 */
	for (i = 0; i < q->nr; i++) {
		struct diff_filepair *p = q->queue[i];
		diff_free_filepair(p);
	}

	/*
	 * .. and re-instate the one we want (which might be either the
	 * original one, or the rename/copy we found)
	 */
	q->queue[0] = choice;
	q->nr = 1;
}

int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base, struct diff_options *opt)
{
	void *tree1, *tree2;
	struct tree_desc t1, t2;
	unsigned long size1, size2;
	int retval;

	tree1 = read_object_with_reference(old, tree_type, &size1, NULL);
	if (!tree1)
		die("unable to read source tree (%s)", sha1_to_hex(old));
	tree2 = read_object_with_reference(new, tree_type, &size2, NULL);
	if (!tree2)
		die("unable to read destination tree (%s)", sha1_to_hex(new));
	init_tree_desc(&t1, tree1, size1);
	init_tree_desc(&t2, tree2, size2);
	retval = diff_tree(&t1, &t2, base, opt);
	if (!*base && DIFF_OPT_TST(opt, FOLLOW_RENAMES) && diff_might_be_rename()) {
		init_tree_desc(&t1, tree1, size1);
		init_tree_desc(&t2, tree2, size2);
		try_to_follow_renames(&t1, &t2, base, opt);
	}
	free(tree1);
	free(tree2);
	return retval;
}

int diff_root_tree_sha1(const unsigned char *new, const char *base, struct diff_options *opt)
{
	int retval;
	void *tree;
	unsigned long size;
	struct tree_desc empty, real;

	tree = read_object_with_reference(new, tree_type, &size, NULL);
	if (!tree)
		die("unable to read root tree (%s)", sha1_to_hex(new));
	init_tree_desc(&real, tree, size);

	init_tree_desc(&empty, "", 0);
	retval = diff_tree(&empty, &real, base, opt);
	free(tree);
	return retval;
}

void diff_tree_release_paths(struct diff_options *opt)
{
	free_pathspec(&opt->pathspec);
}

void diff_tree_setup_paths(const char **p, struct diff_options *opt)
{
	init_pathspec(&opt->pathspec, p);
}
Commit	Line	Data
ac1b3d12 LT	1	/*
	2	* Helper functions for tree diff generation
	3	*/
	4	#include "cache.h"
	5	#include "diff.h"
750f7b66	6	#include "diffcore.h"
8e440259	7	#include "tree.h"
ac1b3d12	8
48932677 NTND	9	static void show_entry(struct diff_options opt, const char prefix,
48932677 NTND	10	struct tree_desc desc, struct strbuf base);
ac1b3d12	11
48932677 NTND	12	static int compare_tree_entry(struct tree_desc t1, struct tree_desc t2,
48932677 NTND	13	struct strbuf base, struct diff_options opt)
ac1b3d12 LT	14	{
	15	unsigned mode1, mode2;
	16	const char path1, path2;
	17	const unsigned char sha1, sha2;
	18	int cmp, pathlen1, pathlen2;
48932677 NTND	19	int old_baselen = base->len;
48932677 NTND	20	int retval = 0;
ac1b3d12	21
50f9a858 LT	22	sha1 = tree_entry_extract(t1, &path1, &mode1);
50f9a858 LT	23	sha2 = tree_entry_extract(t2, &path2, &mode2);
ac1b3d12	24
304de2d2 LT	25	pathlen1 = tree_entry_len(path1, sha1);
304de2d2 LT	26	pathlen2 = tree_entry_len(path2, sha2);
ac1b3d12 LT	27	cmp = base_name_compare(path1, pathlen1, mode1, path2, pathlen2, mode2);
ac1b3d12 LT	28	if (cmp < 0) {
48932677	29	show_entry(opt, "-", t1, base);
ac1b3d12 LT	30	return -1;
	31	}
	32	if (cmp > 0) {
48932677	33	show_entry(opt, "+", t2, base);
ac1b3d12 LT	34	return 1;
ac1b3d12 LT	35	}
8f67f8ae	36	if (!DIFF_OPT_TST(opt, FIND_COPIES_HARDER) && !hashcmp(sha1, sha2) && mode1 == mode2)
ac1b3d12 LT	37	return 0;
	38
	39	/*
	40	* If the filemode has changed to/from a directory from/to a regular
	41	* file, we need to consider it a remove and an add.
	42	*/
	43	if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
48932677 NTND	44	show_entry(opt, "-", t1, base);
48932677 NTND	45	show_entry(opt, "+", t2, base);
ac1b3d12 LT	46	return 0;
	47	}
	48
48932677	49	strbuf_add(base, path1, pathlen1);
8f67f8ae	50	if (DIFF_OPT_TST(opt, RECURSIVE) && S_ISDIR(mode1)) {
fd55a19e	51	if (DIFF_OPT_TST(opt, TREE_IN_RECURSIVE)) {
ac1b3d12	52	opt->change(opt, mode1, mode2,
48932677	53	sha1, sha2, base->buf, 0, 0);
fd55a19e	54	}
48932677 NTND	55	strbuf_addch(base, '/');
	56	retval = diff_tree_sha1(sha1, sha2, base->buf, opt);
	57	} else {
	58	opt->change(opt, mode1, mode2, sha1, sha2, base->buf, 0, 0);
ac1b3d12	59	}
48932677	60	strbuf_setlen(base, old_baselen);
ac1b3d12 LT	61	return 0;
	62	}
	63
ac1b3d12	64	/* A whole sub-tree went away or appeared */
48932677 NTND	65	static void show_tree(struct diff_options opt, const char prefix,
48932677 NTND	66	struct tree_desc desc, struct strbuf base)
ac1b3d12	67	{
1d848f64	68	int all_interesting = 0;
ac1b3d12	69	while (desc->size) {
1d848f64 JH	70	int show;
	71
	72	if (all_interesting)
	73	show = 1;
	74	else {
1376e507	75	show = tree_entry_interesting(&desc->entry, base, 0,
48932677	76	&opt->pathspec);
1d848f64 JH	77	if (show == 2)
	78	all_interesting = 1;
	79	}
5d865017 LT	80	if (show < 0)
	81	break;
	82	if (show)
48932677	83	show_entry(opt, prefix, desc, base);
ac1b3d12 LT	84	update_tree_entry(desc);
	85	}
	86	}
	87
	88	/* A file entry went away or appeared */
48932677 NTND	89	static void show_entry(struct diff_options opt, const char prefix,
48932677 NTND	90	struct tree_desc desc, struct strbuf base)
ac1b3d12 LT	91	{
	92	unsigned mode;
	93	const char *path;
50f9a858	94	const unsigned char *sha1 = tree_entry_extract(desc, &path, &mode);
fd55a19e	95	int pathlen = tree_entry_len(path, sha1);
48932677	96	int old_baselen = base->len;
ac1b3d12	97
48932677	98	strbuf_add(base, path, pathlen);
8f67f8ae	99	if (DIFF_OPT_TST(opt, RECURSIVE) && S_ISDIR(mode)) {
21666f1a	100	enum object_type type;
ac1b3d12 LT	101	struct tree_desc inner;
ac1b3d12 LT	102	void *tree;
6fda5e51	103	unsigned long size;
ac1b3d12	104
6fda5e51	105	tree = read_sha1_file(sha1, &type, &size);
21666f1a	106	if (!tree \|\| type != OBJ_TREE)
ac1b3d12 LT	107	die("corrupt tree sha %s", sha1_to_hex(sha1));
ac1b3d12 LT	108
48932677 NTND	109	if (DIFF_OPT_TST(opt, TREE_IN_RECURSIVE))
48932677 NTND	110	opt->add_remove(opt, *prefix, mode, sha1, base->buf, 0);
df533f34	111
48932677	112	strbuf_addch(base, '/');
ac1b3d12	113
48932677 NTND	114	init_tree_desc(&inner, tree, size);
48932677 NTND	115	show_tree(opt, prefix, &inner, base);
ac1b3d12	116	free(tree);
48932677 NTND	117	} else
	118	opt->add_remove(opt, prefix[0], mode, sha1, base->buf, 0);
	119
	120	strbuf_setlen(base, old_baselen);
ac1b3d12 LT	121	}
ac1b3d12 LT	122
48932677 NTND	123	static void skip_uninteresting(struct tree_desc t, struct strbuf base,
48932677 NTND	124	struct diff_options opt, int all_interesting)
5d865017 LT	125	{
5d865017 LT	126	while (t->size) {
1376e507	127	int show = tree_entry_interesting(&t->entry, base, 0, &opt->pathspec);
7e1ec0d4 EN	128	if (show == 2)
7e1ec0d4 EN	129	*all_interesting = 1;
5d865017 LT	130	if (!show) {
	131	update_tree_entry(t);
	132	continue;
	133	}
	134	/* Skip it all? */
	135	if (show < 0)
	136	t->size = 0;
	137	return;
	138	}
	139	}
	140
48932677 NTND	141	int diff_tree(struct tree_desc t1, struct tree_desc t2,
48932677 NTND	142	const char base_str, struct diff_options opt)
ac1b3d12	143	{
48932677 NTND	144	struct strbuf base;
48932677 NTND	145	int baselen = strlen(base_str);
7e1ec0d4 EN	146	int all_t1_interesting = 0;
7e1ec0d4 EN	147	int all_t2_interesting = 0;
304de2d2	148
bc96cc87 NTND	149	/* Enable recursion indefinitely */
	150	opt->pathspec.recursive = DIFF_OPT_TST(opt, RECURSIVE);
	151	opt->pathspec.max_depth = -1;
	152
48932677 NTND	153	strbuf_init(&base, PATH_MAX);
	154	strbuf_add(&base, base_str, baselen);
	155
5d865017	156	for (;;) {
90b19941	157	if (DIFF_OPT_TST(opt, QUICK) &&
f245194f	158	DIFF_OPT_TST(opt, HAS_CHANGES))
822cac01	159	break;
66f13625	160	if (opt->pathspec.nr) {
7e1ec0d4	161	if (!all_t1_interesting)
48932677	162	skip_uninteresting(t1, &base, opt, &all_t1_interesting);
7e1ec0d4	163	if (!all_t2_interesting)
48932677	164	skip_uninteresting(t2, &base, opt, &all_t2_interesting);
ac1b3d12 LT	165	}
ac1b3d12 LT	166	if (!t1->size) {
5d865017 LT	167	if (!t2->size)
5d865017 LT	168	break;
48932677	169	show_entry(opt, "+", t2, &base);
ac1b3d12 LT	170	update_tree_entry(t2);
	171	continue;
	172	}
	173	if (!t2->size) {
48932677	174	show_entry(opt, "-", t1, &base);
ac1b3d12 LT	175	update_tree_entry(t1);
	176	continue;
	177	}
48932677	178	switch (compare_tree_entry(t1, t2, &base, opt)) {
ac1b3d12 LT	179	case -1:
	180	update_tree_entry(t1);
	181	continue;
	182	case 0:
	183	update_tree_entry(t1);
	184	/* Fallthrough */
	185	case 1:
	186	update_tree_entry(t2);
	187	continue;
	188	}
7e44c935	189	die("git diff-tree: internal error");
ac1b3d12	190	}
48932677 NTND	191
48932677 NTND	192	strbuf_release(&base);
ac1b3d12 LT	193	return 0;
	194	}
	195
750f7b66 LT	196	/*
	197	* Does it look like the resulting diff might be due to a rename?
	198	* - single entry
	199	* - not a valid previous file
	200	*/
	201	static inline int diff_might_be_rename(void)
	202	{
	203	return diff_queued_diff.nr == 1 &&
	204	!DIFF_FILE_VALID(diff_queued_diff.queue[0]->one);
	205	}
	206
	207	static void try_to_follow_renames(struct tree_desc t1, struct tree_desc t2, const char base, struct diff_options opt)
	208	{
	209	struct diff_options diff_opts;
9f38e1ef LT	210	struct diff_queue_struct *q = &diff_queued_diff;
	211	struct diff_filepair *choice;
	212	const char *paths[1];
750f7b66 LT	213	int i;
750f7b66 LT	214
9f38e1ef LT	215	/* Remove the file creation entry from the diff queue, and remember it */
	216	choice = q->queue[0];
	217	q->nr = 0;
	218
750f7b66	219	diff_setup(&diff_opts);
8f67f8ae	220	DIFF_OPT_SET(&diff_opts, RECURSIVE);
0cdca133	221	DIFF_OPT_SET(&diff_opts, FIND_COPIES_HARDER);
750f7b66	222	diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
66f13625	223	diff_opts.single_follow = opt->pathspec.raw[0];
6dd4b66f	224	diff_opts.break_opt = opt->break_opt;
750f7b66 LT	225	paths[0] = NULL;
	226	diff_tree_setup_paths(paths, &diff_opts);
	227	if (diff_setup_done(&diff_opts) < 0)
	228	die("unable to set up diff options to follow renames");
	229	diff_tree(t1, t2, base, &diff_opts);
	230	diffcore_std(&diff_opts);
03b69c76	231	diff_tree_release_paths(&diff_opts);
750f7b66	232
9f38e1ef	233	/* Go through the new set of filepairing, and see if we find a more interesting one */
44c48a90	234	opt->found_follow = 0;
9f38e1ef LT	235	for (i = 0; i < q->nr; i++) {
9f38e1ef LT	236	struct diff_filepair *p = q->queue[i];
750f7b66 LT	237
	238	/*
	239	* Found a source? Not only do we use that for the new
9f38e1ef	240	* diff_queued_diff, we will also use that as the path in
750f7b66 LT	241	* the future!
750f7b66 LT	242	*/
66f13625 NTND	243	if ((p->status == 'R' \|\| p->status == 'C') &&
66f13625 NTND	244	!strcmp(p->two->path, opt->pathspec.raw[0])) {
9f38e1ef LT	245	/* Switch the file-pairs around */
	246	q->queue[i] = choice;
	247	choice = p;
	248
	249	/* Update the path we use from now on.. */
03b69c76	250	diff_tree_release_paths(opt);
66f13625 NTND	251	opt->pathspec.raw[0] = xstrdup(p->one->path);
66f13625 NTND	252	diff_tree_setup_paths(opt->pathspec.raw, opt);
44c48a90 JH	253
	254	/*
	255	* The caller expects us to return a set of vanilla
	256	* filepairs to let a later call to diffcore_std()
	257	* it makes to sort the renames out (among other
	258	* things), but we already have found renames
	259	* ourselves; signal diffcore_std() not to muck with
	260	* rename information.
	261	*/
	262	opt->found_follow = 1;
750f7b66 LT	263	break;
	264	}
	265	}
	266
	267	/*
3ea3c215	268	* Then, discard all the non-relevant file pairs...
9f38e1ef LT	269	*/
	270	for (i = 0; i < q->nr; i++) {
	271	struct diff_filepair *p = q->queue[i];
	272	diff_free_filepair(p);
	273	}
	274
	275	/*
	276	* .. and re-instate the one we want (which might be either the
	277	* original one, or the rename/copy we found)
750f7b66	278	*/
9f38e1ef LT	279	q->queue[0] = choice;
9f38e1ef LT	280	q->nr = 1;
750f7b66 LT	281	}
750f7b66 LT	282
ac1b3d12 LT	283	int diff_tree_sha1(const unsigned char old, const unsigned char new, const char base, struct diff_options opt)
	284	{
	285	void tree1, tree2;
	286	struct tree_desc t1, t2;
6fda5e51	287	unsigned long size1, size2;
ac1b3d12 LT	288	int retval;
ac1b3d12 LT	289
6fda5e51	290	tree1 = read_object_with_reference(old, tree_type, &size1, NULL);
ac1b3d12 LT	291	if (!tree1)
ac1b3d12 LT	292	die("unable to read source tree (%s)", sha1_to_hex(old));
6fda5e51	293	tree2 = read_object_with_reference(new, tree_type, &size2, NULL);
ac1b3d12 LT	294	if (!tree2)
ac1b3d12 LT	295	die("unable to read destination tree (%s)", sha1_to_hex(new));
6fda5e51 LT	296	init_tree_desc(&t1, tree1, size1);
6fda5e51 LT	297	init_tree_desc(&t2, tree2, size2);
ac1b3d12	298	retval = diff_tree(&t1, &t2, base, opt);
39f75d26	299	if (!*base && DIFF_OPT_TST(opt, FOLLOW_RENAMES) && diff_might_be_rename()) {
750f7b66 LT	300	init_tree_desc(&t1, tree1, size1);
	301	init_tree_desc(&t2, tree2, size2);
	302	try_to_follow_renames(&t1, &t2, base, opt);
	303	}
ac1b3d12 LT	304	free(tree1);
	305	free(tree2);
	306	return retval;
	307	}
	308
2b60356d RS	309	int diff_root_tree_sha1(const unsigned char new, const char base, struct diff_options *opt)
	310	{
	311	int retval;
	312	void *tree;
6fda5e51	313	unsigned long size;
2b60356d RS	314	struct tree_desc empty, real;
2b60356d RS	315
6fda5e51	316	tree = read_object_with_reference(new, tree_type, &size, NULL);
2b60356d RS	317	if (!tree)
2b60356d RS	318	die("unable to read root tree (%s)", sha1_to_hex(new));
6fda5e51	319	init_tree_desc(&real, tree, size);
2b60356d	320
6fda5e51	321	init_tree_desc(&empty, "", 0);
2b60356d RS	322	retval = diff_tree(&empty, &real, base, opt);
	323	free(tree);
	324	return retval;
	325	}
	326
a8baa7b9	327	void diff_tree_release_paths(struct diff_options *opt)
ac1b3d12	328	{
66f13625	329	free_pathspec(&opt->pathspec);
a8baa7b9 JH	330	}
	331
	332	void diff_tree_setup_paths(const char *p, struct diff_options opt)
	333	{
66f13625	334	init_pathspec(&opt->pathspec, p);
ac1b3d12	335	}