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

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

static char *malloc_base(const char *base, int baselen, const char *path, int pathlen)
{
	char *newbase = xmalloc(baselen + pathlen + 2);
	memcpy(newbase, base, baselen);
	memcpy(newbase + baselen, path, pathlen);
	memcpy(newbase + baselen + pathlen, "/", 2);
	return newbase;
}

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

static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2, const char *base, int baselen, struct diff_options *opt)
{
	unsigned mode1, mode2;
	const char *path1, *path2;
	const unsigned char *sha1, *sha2;
	int cmp, pathlen1, pathlen2;

	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, baselen);
		return -1;
	}
	if (cmp > 0) {
		show_entry(opt, "+", t2, base, baselen);
		return 1;
	}
	if (!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, baselen);
		show_entry(opt, "+", t2, base, baselen);
		return 0;
	}

	if (opt->recursive && S_ISDIR(mode1)) {
		int retval;
		char *newbase = malloc_base(base, baselen, path1, pathlen1);
		if (opt->tree_in_recursive)
			opt->change(opt, mode1, mode2,
				    sha1, sha2, base, path1);
		retval = diff_tree_sha1(sha1, sha2, newbase, opt);
		free(newbase);
		return retval;
	}

	opt->change(opt, mode1, mode2, sha1, sha2, base, path1);
	return 0;
}

/*
 * Is a tree entry interesting given the pathspec we have?
 *
 * Return:
 *  - positive for yes
 *  - zero for no
 *  - negative for "no, and no subsequent entries will be either"
 */
static int tree_entry_interesting(struct tree_desc *desc, const char *base, int baselen, struct diff_options *opt)
{
	const char *path;
	const unsigned char *sha1;
	unsigned mode;
	int i;
	int pathlen;

	if (!opt->nr_paths)
		return 1;

	sha1 = tree_entry_extract(desc, &path, &mode);

	pathlen = tree_entry_len(path, sha1);

	for (i=0; i < opt->nr_paths; i++) {
		const char *match = opt->paths[i];
		int matchlen = opt->pathlens[i];

		if (baselen >= matchlen) {
			/* If it doesn't match, move along... */
			if (strncmp(base, match, matchlen))
				continue;

			/* The base is a subdirectory of a path which was specified. */
			return 1;
		}

		/* Does the base match? */
		if (strncmp(base, match, baselen))
			continue;

		match += baselen;
		matchlen -= baselen;

		if (pathlen > matchlen)
			continue;

		if (matchlen > pathlen) {
			if (match[pathlen] != '/')
				continue;
			if (!S_ISDIR(mode))
				continue;
		}

		if (strncmp(path, match, pathlen))
			continue;

		return 1;
	}
	return 0; /* No matches */
}

/* A whole sub-tree went away or appeared */
static void show_tree(struct diff_options *opt, const char *prefix, struct tree_desc *desc, const char *base, int baselen)
{
	while (desc->size) {
		int show = tree_entry_interesting(desc, base, baselen, opt);
		if (show < 0)
			break;
		if (show)
			show_entry(opt, prefix, desc, base, baselen);
		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,
		       const char *base, int baselen)
{
	unsigned mode;
	const char *path;
	const unsigned char *sha1 = tree_entry_extract(desc, &path, &mode);

	if (opt->recursive && S_ISDIR(mode)) {
		enum object_type type;
		int pathlen = tree_entry_len(path, sha1);
		char *newbase = malloc_base(base, baselen, path, pathlen);
		struct tree_desc inner;
		void *tree;

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

		inner.buf = tree;
		show_tree(opt, prefix, &inner, newbase, baselen + 1 + pathlen);

		free(tree);
		free(newbase);
	} else {
		opt->add_remove(opt, prefix[0], mode, sha1, base, path);
	}
}

static void skip_uninteresting(struct tree_desc *t, const char *base, int baselen, struct diff_options *opt)
{
	while (t->size) {
		int show = tree_entry_interesting(t, base, baselen, opt);
		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, struct diff_options *opt)
{
	int baselen = strlen(base);

	for (;;) {
		if (opt->quiet && opt->has_changes)
			break;
		if (opt->nr_paths) {
			skip_uninteresting(t1, base, baselen, opt);
			skip_uninteresting(t2, base, baselen, opt);
		}
		if (!t1->size) {
			if (!t2->size)
				break;
			show_entry(opt, "+", t2, base, baselen);
			update_tree_entry(t2);
			continue;
		}
		if (!t2->size) {
			show_entry(opt, "-", t1, base, baselen);
			update_tree_entry(t1);
			continue;
		}
		switch (compare_tree_entry(t1, t2, base, baselen, 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");
	}
	return 0;
}

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;
	int retval;

	tree1 = read_object_with_reference(old, tree_type, &t1.size, NULL);
	if (!tree1)
		die("unable to read source tree (%s)", sha1_to_hex(old));
	tree2 = read_object_with_reference(new, tree_type, &t2.size, NULL);
	if (!tree2)
		die("unable to read destination tree (%s)", sha1_to_hex(new));
	t1.buf = tree1;
	t2.buf = tree2;
	retval = diff_tree(&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;
	struct tree_desc empty, real;

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

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

static int count_paths(const char **paths)
{
	int i = 0;
	while (*paths++)
		i++;
	return i;
}

void diff_tree_release_paths(struct diff_options *opt)
{
	free(opt->pathlens);
}

void diff_tree_setup_paths(const char **p, struct diff_options *opt)
{
	opt->nr_paths = 0;
	opt->pathlens = NULL;
	opt->paths = NULL;

	if (p) {
		int i;

		opt->paths = p;
		opt->nr_paths = count_paths(p);
		if (opt->nr_paths == 0) {
			opt->pathlens = NULL;
			return;
		}
		opt->pathlens = xmalloc(opt->nr_paths * sizeof(int));
		for (i=0; i < opt->nr_paths; i++)
			opt->pathlens[i] = strlen(p[i]);
	}
}
Commit	Line	Data
ac1b3d12 LT	1	/*
	2	* Helper functions for tree diff generation
	3	*/
	4	#include "cache.h"
	5	#include "diff.h"
8e440259	6	#include "tree.h"
ac1b3d12	7
304de2d2	8	static char malloc_base(const char base, int baselen, const char *path, int pathlen)
ac1b3d12	9	{
ac1b3d12 LT	10	char *newbase = xmalloc(baselen + pathlen + 2);
	11	memcpy(newbase, base, baselen);
	12	memcpy(newbase + baselen, path, pathlen);
	13	memcpy(newbase + baselen + pathlen, "/", 2);
	14	return newbase;
	15	}
	16
cf995ede	17	static void show_entry(struct diff_options opt, const char prefix, struct tree_desc *desc,
304de2d2	18	const char *base, int baselen);
ac1b3d12	19
304de2d2	20	static int compare_tree_entry(struct tree_desc t1, struct tree_desc t2, const char base, int baselen, struct diff_options opt)
ac1b3d12 LT	21	{
	22	unsigned mode1, mode2;
	23	const char path1, path2;
	24	const unsigned char sha1, sha2;
	25	int cmp, pathlen1, pathlen2;
	26
50f9a858 LT	27	sha1 = tree_entry_extract(t1, &path1, &mode1);
50f9a858 LT	28	sha2 = tree_entry_extract(t2, &path2, &mode2);
ac1b3d12	29
304de2d2 LT	30	pathlen1 = tree_entry_len(path1, sha1);
304de2d2 LT	31	pathlen2 = tree_entry_len(path2, sha2);
ac1b3d12 LT	32	cmp = base_name_compare(path1, pathlen1, mode1, path2, pathlen2, mode2);
ac1b3d12 LT	33	if (cmp < 0) {
304de2d2	34	show_entry(opt, "-", t1, base, baselen);
ac1b3d12 LT	35	return -1;
	36	}
	37	if (cmp > 0) {
304de2d2	38	show_entry(opt, "+", t2, base, baselen);
ac1b3d12 LT	39	return 1;
ac1b3d12 LT	40	}
a89fccd2	41	if (!opt->find_copies_harder && !hashcmp(sha1, sha2) && mode1 == mode2)
ac1b3d12 LT	42	return 0;
	43
	44	/*
	45	* If the filemode has changed to/from a directory from/to a regular
	46	* file, we need to consider it a remove and an add.
	47	*/
	48	if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
304de2d2 LT	49	show_entry(opt, "-", t1, base, baselen);
304de2d2 LT	50	show_entry(opt, "+", t2, base, baselen);
ac1b3d12 LT	51	return 0;
	52	}
	53
	54	if (opt->recursive && S_ISDIR(mode1)) {
	55	int retval;
304de2d2	56	char *newbase = malloc_base(base, baselen, path1, pathlen1);
ac1b3d12 LT	57	if (opt->tree_in_recursive)
	58	opt->change(opt, mode1, mode2,
	59	sha1, sha2, base, path1);
	60	retval = diff_tree_sha1(sha1, sha2, newbase, opt);
	61	free(newbase);
	62	return retval;
	63	}
	64
	65	opt->change(opt, mode1, mode2, sha1, sha2, base, path1);
	66	return 0;
	67	}
	68
5d865017 LT	69	/*
	70	* Is a tree entry interesting given the pathspec we have?
	71	*
	72	* Return:
	73	* - positive for yes
	74	* - zero for no
	75	* - negative for "no, and no subsequent entries will be either"
	76	*/
	77	static int tree_entry_interesting(struct tree_desc desc, const char base, int baselen, struct diff_options *opt)
ac1b3d12 LT	78	{
ac1b3d12 LT	79	const char *path;
304de2d2	80	const unsigned char *sha1;
ac1b3d12 LT	81	unsigned mode;
ac1b3d12 LT	82	int i;
304de2d2	83	int pathlen;
ac1b3d12	84
a8baa7b9	85	if (!opt->nr_paths)
ac1b3d12 LT	86	return 1;
ac1b3d12 LT	87
304de2d2	88	sha1 = tree_entry_extract(desc, &path, &mode);
ac1b3d12	89
304de2d2	90	pathlen = tree_entry_len(path, sha1);
ac1b3d12	91
a8baa7b9 JH	92	for (i=0; i < opt->nr_paths; i++) {
	93	const char *match = opt->paths[i];
	94	int matchlen = opt->pathlens[i];
ac1b3d12 LT	95
	96	if (baselen >= matchlen) {
	97	/* If it doesn't match, move along... */
	98	if (strncmp(base, match, matchlen))
	99	continue;
	100
	101	/* The base is a subdirectory of a path which was specified. */
	102	return 1;
	103	}
	104
	105	/* Does the base match? */
	106	if (strncmp(base, match, baselen))
	107	continue;
	108
	109	match += baselen;
	110	matchlen -= baselen;
	111
	112	if (pathlen > matchlen)
	113	continue;
	114
	115	if (matchlen > pathlen) {
	116	if (match[pathlen] != '/')
	117	continue;
	118	if (!S_ISDIR(mode))
	119	continue;
	120	}
	121
	122	if (strncmp(path, match, pathlen))
	123	continue;
	124
	125	return 1;
	126	}
	127	return 0; /* No matches */
	128	}
	129
	130	/* A whole sub-tree went away or appeared */
304de2d2	131	static void show_tree(struct diff_options opt, const char prefix, struct tree_desc desc, const char base, int baselen)
ac1b3d12 LT	132	{
ac1b3d12 LT	133	while (desc->size) {
5d865017 LT	134	int show = tree_entry_interesting(desc, base, baselen, opt);
	135	if (show < 0)
	136	break;
	137	if (show)
304de2d2	138	show_entry(opt, prefix, desc, base, baselen);
ac1b3d12 LT	139	update_tree_entry(desc);
	140	}
	141	}
	142
	143	/* A file entry went away or appeared */
cf995ede	144	static void show_entry(struct diff_options opt, const char prefix, struct tree_desc *desc,
304de2d2	145	const char *base, int baselen)
ac1b3d12 LT	146	{
	147	unsigned mode;
	148	const char *path;
50f9a858	149	const unsigned char *sha1 = tree_entry_extract(desc, &path, &mode);
ac1b3d12 LT	150
ac1b3d12 LT	151	if (opt->recursive && S_ISDIR(mode)) {
21666f1a	152	enum object_type type;
304de2d2 LT	153	int pathlen = tree_entry_len(path, sha1);
304de2d2 LT	154	char *newbase = malloc_base(base, baselen, path, pathlen);
ac1b3d12 LT	155	struct tree_desc inner;
	156	void *tree;
	157
21666f1a NP	158	tree = read_sha1_file(sha1, &type, &inner.size);
21666f1a NP	159	if (!tree \|\| type != OBJ_TREE)
ac1b3d12 LT	160	die("corrupt tree sha %s", sha1_to_hex(sha1));
	161
	162	inner.buf = tree;
304de2d2	163	show_tree(opt, prefix, &inner, newbase, baselen + 1 + pathlen);
ac1b3d12 LT	164
	165	free(tree);
	166	free(newbase);
cf995ede DR	167	} else {
cf995ede DR	168	opt->add_remove(opt, prefix[0], mode, sha1, base, path);
ac1b3d12	169	}
ac1b3d12 LT	170	}
ac1b3d12 LT	171
5d865017 LT	172	static void skip_uninteresting(struct tree_desc t, const char base, int baselen, struct diff_options *opt)
	173	{
	174	while (t->size) {
	175	int show = tree_entry_interesting(t, base, baselen, opt);
	176	if (!show) {
	177	update_tree_entry(t);
	178	continue;
	179	}
	180	/* Skip it all? */
	181	if (show < 0)
	182	t->size = 0;
	183	return;
	184	}
	185	}
	186
ac1b3d12 LT	187	int diff_tree(struct tree_desc t1, struct tree_desc t2, const char base, struct diff_options opt)
ac1b3d12 LT	188	{
304de2d2 LT	189	int baselen = strlen(base);
304de2d2 LT	190
5d865017	191	for (;;) {
822cac01 JH	192	if (opt->quiet && opt->has_changes)
822cac01 JH	193	break;
5d865017 LT	194	if (opt->nr_paths) {
	195	skip_uninteresting(t1, base, baselen, opt);
	196	skip_uninteresting(t2, base, baselen, opt);
ac1b3d12 LT	197	}
ac1b3d12 LT	198	if (!t1->size) {
5d865017 LT	199	if (!t2->size)
5d865017 LT	200	break;
304de2d2	201	show_entry(opt, "+", t2, base, baselen);
ac1b3d12 LT	202	update_tree_entry(t2);
	203	continue;
	204	}
	205	if (!t2->size) {
304de2d2	206	show_entry(opt, "-", t1, base, baselen);
ac1b3d12 LT	207	update_tree_entry(t1);
	208	continue;
	209	}
304de2d2	210	switch (compare_tree_entry(t1, t2, base, baselen, opt)) {
ac1b3d12 LT	211	case -1:
	212	update_tree_entry(t1);
	213	continue;
	214	case 0:
	215	update_tree_entry(t1);
	216	/* Fallthrough */
	217	case 1:
	218	update_tree_entry(t2);
	219	continue;
	220	}
	221	die("git-diff-tree: internal error");
	222	}
	223	return 0;
	224	}
	225
	226	int diff_tree_sha1(const unsigned char old, const unsigned char new, const char base, struct diff_options opt)
	227	{
	228	void tree1, tree2;
	229	struct tree_desc t1, t2;
	230	int retval;
	231
8e440259	232	tree1 = read_object_with_reference(old, tree_type, &t1.size, NULL);
ac1b3d12 LT	233	if (!tree1)
ac1b3d12 LT	234	die("unable to read source tree (%s)", sha1_to_hex(old));
8e440259	235	tree2 = read_object_with_reference(new, tree_type, &t2.size, NULL);
ac1b3d12 LT	236	if (!tree2)
	237	die("unable to read destination tree (%s)", sha1_to_hex(new));
	238	t1.buf = tree1;
	239	t2.buf = tree2;
	240	retval = diff_tree(&t1, &t2, base, opt);
	241	free(tree1);
	242	free(tree2);
	243	return retval;
	244	}
	245
2b60356d RS	246	int diff_root_tree_sha1(const unsigned char new, const char base, struct diff_options *opt)
	247	{
	248	int retval;
	249	void *tree;
	250	struct tree_desc empty, real;
	251
	252	tree = read_object_with_reference(new, tree_type, &real.size, NULL);
	253	if (!tree)
	254	die("unable to read root tree (%s)", sha1_to_hex(new));
	255	real.buf = tree;
	256
	257	empty.size = 0;
	258	empty.buf = "";
	259	retval = diff_tree(&empty, &real, base, opt);
	260	free(tree);
	261	return retval;
	262	}
	263
ac1b3d12 LT	264	static int count_paths(const char **paths)
	265	{
	266	int i = 0;
	267	while (*paths++)
	268	i++;
	269	return i;
	270	}
	271
a8baa7b9	272	void diff_tree_release_paths(struct diff_options *opt)
ac1b3d12	273	{
a8baa7b9 JH	274	free(opt->pathlens);
	275	}
	276
	277	void diff_tree_setup_paths(const char *p, struct diff_options opt)
	278	{
	279	opt->nr_paths = 0;
	280	opt->pathlens = NULL;
	281	opt->paths = NULL;
	282
ac1b3d12 LT	283	if (p) {
	284	int i;
	285
a8baa7b9 JH	286	opt->paths = p;
	287	opt->nr_paths = count_paths(p);
	288	if (opt->nr_paths == 0) {
	289	opt->pathlens = NULL;
7e4a2a84 JH	290	return;
7e4a2a84 JH	291	}
a8baa7b9 JH	292	opt->pathlens = xmalloc(opt->nr_paths * sizeof(int));
	293	for (i=0; i < opt->nr_paths; i++)
	294	opt->pathlens[i] = strlen(p[i]);
ac1b3d12 LT	295	}
ac1b3d12 LT	296	}