[thirdparty/git.git] / line-range.c

#include "git-compat-util.h"
#include "line-range.h"
#include "xdiff-interface.h"
#include "strbuf.h"
#include "userdiff.h"

/*
 * Parse one item in the -L option
 *
 * 'begin' is applicable only to relative range anchors. Absolute anchors
 * ignore this value.
 *
 * When parsing "-L A,B", parse_loc() is called once for A and once for B.
 *
 * When parsing A, 'begin' must be a negative number, the absolute value of
 * which is the line at which relative start-of-range anchors should be
 * based. Beginning of file is represented by -1.
 *
 * When parsing B, 'begin' must be the positive line number immediately
 * following the line computed for 'A'.
 */
static const char *parse_loc(const char *spec, nth_line_fn_t nth_line,
			     void *data, long lines, long begin, long *ret)
{
	char *term;
	const char *line;
	long num;
	int reg_error;
	regex_t regexp;
	regmatch_t match[1];

	/* Allow "-L <something>,+20" to mean starting at <something>
	 * for 20 lines, or "-L <something>,-5" for 5 lines ending at
	 * <something>.
	 */
	if (1 <= begin && (spec[0] == '+' || spec[0] == '-')) {
		num = strtol(spec + 1, &term, 10);
		if (term != spec + 1) {
			if (!ret)
				return term;
			if (num == 0)
				die("-L invalid empty range");
			if (spec[0] == '-')
				num = 0 - num;
			if (0 < num)
				*ret = begin + num - 2;
			else if (!num)
				*ret = begin;
			else
				*ret = begin + num > 0 ? begin + num : 1;
			return term;
		}
		return spec;
	}
	num = strtol(spec, &term, 10);
	if (term != spec) {
		if (ret) {
			if (num <= 0)
				die("-L invalid line number: %ld", num);
			*ret = num;
		}
		return term;
	}

	if (begin < 0) {
		if (spec[0] != '^')
			begin = -begin;
		else {
			begin = 1;
			spec++;
		}
	}

	if (spec[0] != '/')
		return spec;

	/* it could be a regexp of form /.../ */
	for (term = (char *) spec + 1; *term && *term != '/'; term++) {
		if (*term == '\\')
			term++;
	}
	if (*term != '/')
		return spec;

	/* in the scan-only case we are not interested in the regex */
	if (!ret)
		return term+1;

	/* try [spec+1 .. term-1] as regexp */
	*term = 0;
	begin--; /* input is in human terms */
	line = nth_line(data, begin);

	if (!(reg_error = regcomp(&regexp, spec + 1, REG_NEWLINE)) &&
	    !(reg_error = regexec(&regexp, line, 1, match, 0))) {
		const char *cp = line + match[0].rm_so;
		const char *nline;

		while (begin++ < lines) {
			nline = nth_line(data, begin);
			if (line <= cp && cp < nline)
				break;
			line = nline;
		}
		*ret = begin;
		regfree(&regexp);
		*term++ = '/';
		return term;
	}
	else {
		char errbuf[1024];
		regerror(reg_error, &regexp, errbuf, 1024);
		die("-L parameter '%s' starting at line %ld: %s",
		    spec + 1, begin + 1, errbuf);
	}
}

static int match_funcname(xdemitconf_t *xecfg, const char *bol, const char *eol)
{
	if (xecfg) {
		char buf[1];
		return xecfg->find_func(bol, eol - bol, buf, 1,
					xecfg->find_func_priv) >= 0;
	}

	if (bol == eol)
		return 0;
	if (isalpha(*bol) || *bol == '_' || *bol == '$')
		return 1;
	return 0;
}

static const char *find_funcname_matching_regexp(xdemitconf_t *xecfg, const char *start,
						 regex_t *regexp)
{
	int reg_error;
	regmatch_t match[1];
	while (*start) {
		const char *bol, *eol;
		reg_error = regexec(regexp, start, 1, match, 0);
		if (reg_error == REG_NOMATCH)
			return NULL;
		else if (reg_error) {
			char errbuf[1024];
			regerror(reg_error, regexp, errbuf, 1024);
			die("-L parameter: regexec() failed: %s", errbuf);
		}
		/* determine extent of line matched */
		bol = start+match[0].rm_so;
		eol = start+match[0].rm_eo;
		while (bol > start && *--bol != '\n')
			; /* nothing */
		if (*bol == '\n')
			bol++;
		while (*eol && *eol != '\n')
			eol++;
		if (*eol == '\n')
			eol++;
		/* is it a funcname line? */
		if (match_funcname(xecfg, (char*) bol, (char*) eol))
			return bol;
		start = eol;
	}
	return NULL;
}

static const char *parse_range_funcname(
	const char *arg, nth_line_fn_t nth_line_cb,
	void *cb_data, long lines, long anchor, long *begin, long *end,
	const char *path, struct index_state *istate)
{
	char *pattern;
	const char *term;
	struct userdiff_driver *drv;
	xdemitconf_t *xecfg = NULL;
	const char *start;
	const char *p;
	int reg_error;
	regex_t regexp;

	if (*arg == '^') {
		anchor = 1;
		arg++;
	}

	assert(*arg == ':');
	term = arg+1;
	while (*term && *term != ':') {
		if (*term == '\\' && *(term+1))
			term++;
		term++;
	}
	if (term == arg+1)
		return NULL;
	if (!begin) /* skip_range_arg case */
		return term;

	pattern = xstrndup(arg+1, term-(arg+1));

	anchor--; /* input is in human terms */
	start = nth_line_cb(cb_data, anchor);

	drv = userdiff_find_by_path(istate, path);
	if (drv && drv->funcname.pattern) {
		const struct userdiff_funcname *pe = &drv->funcname;
		CALLOC_ARRAY(xecfg, 1);
		xdiff_set_find_func(xecfg, pe->pattern, pe->cflags);
	}

	reg_error = regcomp(&regexp, pattern, REG_NEWLINE);
	if (reg_error) {
		char errbuf[1024];
		regerror(reg_error, &regexp, errbuf, 1024);
		die("-L parameter '%s': %s", pattern, errbuf);
	}

	p = find_funcname_matching_regexp(xecfg, (char*) start, &regexp);
	if (!p)
		die("-L parameter '%s' starting at line %ld: no match",
		    pattern, anchor + 1);
	*begin = 0;
	while (p > nth_line_cb(cb_data, *begin))
		(*begin)++;

	if (*begin >= lines)
		die("-L parameter '%s' matches at EOF", pattern);

	*end = *begin+1;
	while (*end < lines) {
		const char *bol = nth_line_cb(cb_data, *end);
		const char *eol = nth_line_cb(cb_data, *end+1);
		if (match_funcname(xecfg, bol, eol))
			break;
		(*end)++;
	}

	regfree(&regexp);
	free(xecfg);
	free(pattern);

	/* compensate for 1-based numbering */
	(*begin)++;

	return term;
}

int parse_range_arg(const char *arg, nth_line_fn_t nth_line_cb,
		    void *cb_data, long lines, long anchor,
		    long *begin, long *end,
		    const char *path, struct index_state *istate)
{
	*begin = *end = 0;

	if (anchor < 1)
		anchor = 1;
	if (anchor > lines)
		anchor = lines + 1;

	if (*arg == ':' || (*arg == '^' && *(arg + 1) == ':')) {
		arg = parse_range_funcname(arg, nth_line_cb, cb_data,
					   lines, anchor, begin, end,
					   path, istate);
		if (!arg || *arg)
			return -1;
		return 0;
	}

	arg = parse_loc(arg, nth_line_cb, cb_data, lines, -anchor, begin);

	if (*arg == ',')
		arg = parse_loc(arg + 1, nth_line_cb, cb_data, lines, *begin + 1, end);

	if (*arg)
		return -1;

	if (*begin && *end && *end < *begin) {
		SWAP(*end, *begin);
	}

	return 0;
}

const char *skip_range_arg(const char *arg, struct index_state *istate)
{
	if (*arg == ':' || (*arg == '^' && *(arg + 1) == ':'))
		return parse_range_funcname(arg, NULL, NULL,
					    0, 0, NULL, NULL,
					    NULL, istate);

	arg = parse_loc(arg, NULL, NULL, 0, -1, NULL);

	if (*arg == ',')
		arg = parse_loc(arg+1, NULL, NULL, 0, 0, NULL);

	return arg;
}
Commit	Line	Data
25ed3412 BY	1	#include "git-compat-util.h"
25ed3412 BY	2	#include "line-range.h"
13b8f68c TR	3	#include "xdiff-interface.h"
	4	#include "strbuf.h"
	5	#include "userdiff.h"
25ed3412 BY	6
	7	/*
	8	* Parse one item in the -L option
815834e9 ES	9	*
	10	* 'begin' is applicable only to relative range anchors. Absolute anchors
	11	* ignore this value.
	12	*
	13	* When parsing "-L A,B", parse_loc() is called once for A and once for B.
	14	*
	15	* When parsing A, 'begin' must be a negative number, the absolute value of
	16	* which is the line at which relative start-of-range anchors should be
	17	* based. Beginning of file is represented by -1.
	18	*
	19	* When parsing B, 'begin' must be the positive line number immediately
	20	* following the line computed for 'A'.
25ed3412 BY	21	*/
	22	static const char parse_loc(const char spec, nth_line_fn_t nth_line,
	23	void data, long lines, long begin, long ret)
	24	{
	25	char *term;
	26	const char *line;
	27	long num;
	28	int reg_error;
	29	regex_t regexp;
	30	regmatch_t match[1];
	31
	32	/* Allow "-L <something>,+20" to mean starting at <something>
	33	* for 20 lines, or "-L <something>,-5" for 5 lines ending at
	34	* <something>.
	35	*/
5d57cac6	36	if (1 <= begin && (spec[0] == '+' \|\| spec[0] == '-')) {
25ed3412 BY	37	num = strtol(spec + 1, &term, 10);
25ed3412 BY	38	if (term != spec + 1) {
12da1d1f TR	39	if (!ret)
12da1d1f TR	40	return term;
abba3539 ES	41	if (num == 0)
abba3539 ES	42	die("-L invalid empty range");
25ed3412 BY	43	if (spec[0] == '-')
	44	num = 0 - num;
	45	if (0 < num)
	46	*ret = begin + num - 2;
	47	else if (!num)
	48	*ret = begin;
	49	else
96cfa94e	50	*ret = begin + num > 0 ? begin + num : 1;
25ed3412 BY	51	return term;
	52	}
	53	return spec;
	54	}
	55	num = strtol(spec, &term, 10);
	56	if (term != spec) {
5ce922a0 ES	57	if (ret) {
	58	if (num <= 0)
	59	die("-L invalid line number: %ld", num);
12da1d1f	60	*ret = num;
5ce922a0	61	}
25ed3412 BY	62	return term;
25ed3412 BY	63	}
815834e9	64
a6ac5f98 ES	65	if (begin < 0) {
	66	if (spec[0] != '^')
	67	begin = -begin;
	68	else {
	69	begin = 1;
	70	spec++;
	71	}
	72	}
815834e9	73
25ed3412 BY	74	if (spec[0] != '/')
	75	return spec;
	76
	77	/* it could be a regexp of form /.../ */
	78	for (term = (char ) spec + 1; term && *term != '/'; term++) {
	79	if (*term == '\\')
	80	term++;
	81	}
	82	if (*term != '/')
	83	return spec;
	84
12da1d1f TR	85	/* in the scan-only case we are not interested in the regex */
	86	if (!ret)
	87	return term+1;
	88
25ed3412 BY	89	/* try [spec+1 .. term-1] as regexp */
	90	*term = 0;
	91	begin--; /* input is in human terms */
	92	line = nth_line(data, begin);
	93
	94	if (!(reg_error = regcomp(&regexp, spec + 1, REG_NEWLINE)) &&
	95	!(reg_error = regexec(&regexp, line, 1, match, 0))) {
	96	const char *cp = line + match[0].rm_so;
	97	const char *nline;
	98
	99	while (begin++ < lines) {
	100	nline = nth_line(data, begin);
	101	if (line <= cp && cp < nline)
	102	break;
	103	line = nline;
	104	}
	105	*ret = begin;
	106	regfree(&regexp);
	107	*term++ = '/';
	108	return term;
	109	}
	110	else {
	111	char errbuf[1024];
	112	regerror(reg_error, &regexp, errbuf, 1024);
815834e9 ES	113	die("-L parameter '%s' starting at line %ld: %s",
815834e9 ES	114	spec + 1, begin + 1, errbuf);
25ed3412 BY	115	}
	116	}
	117
13b8f68c TR	118	static int match_funcname(xdemitconf_t xecfg, const char bol, const char *eol)
	119	{
	120	if (xecfg) {
	121	char buf[1];
	122	return xecfg->find_func(bol, eol - bol, buf, 1,
	123	xecfg->find_func_priv) >= 0;
	124	}
	125
	126	if (bol == eol)
	127	return 0;
	128	if (isalpha(bol) \|\| bol == '_' \|\| *bol == '$')
	129	return 1;
	130	return 0;
	131	}
	132
	133	static const char find_funcname_matching_regexp(xdemitconf_t xecfg, const char *start,
	134	regex_t *regexp)
	135	{
	136	int reg_error;
	137	regmatch_t match[1];
4e57c88e	138	while (*start) {
13b8f68c TR	139	const char bol, eol;
	140	reg_error = regexec(regexp, start, 1, match, 0);
	141	if (reg_error == REG_NOMATCH)
	142	return NULL;
	143	else if (reg_error) {
	144	char errbuf[1024];
	145	regerror(reg_error, regexp, errbuf, 1024);
	146	die("-L parameter: regexec() failed: %s", errbuf);
	147	}
	148	/* determine extent of line matched */
	149	bol = start+match[0].rm_so;
	150	eol = start+match[0].rm_eo;
4e57c88e LKS	151	while (bol > start && *--bol != '\n')
4e57c88e LKS	152	; /* nothing */
13b8f68c TR	153	if (*bol == '\n')
	154	bol++;
	155	while (eol && eol != '\n')
	156	eol++;
	157	if (*eol == '\n')
	158	eol++;
	159	/* is it a funcname line? */
	160	if (match_funcname(xecfg, (char) bol, (char) eol))
	161	return bol;
	162	start = eol;
	163	}
4e57c88e	164	return NULL;
13b8f68c TR	165	}
13b8f68c TR	166
80e03855 NTND	167	static const char *parse_range_funcname(
	168	const char *arg, nth_line_fn_t nth_line_cb,
	169	void cb_data, long lines, long anchor, long begin, long *end,
	170	const char path, struct index_state istate)
13b8f68c TR	171	{
	172	char *pattern;
	173	const char *term;
	174	struct userdiff_driver *drv;
	175	xdemitconf_t *xecfg = NULL;
	176	const char *start;
	177	const char *p;
	178	int reg_error;
	179	regex_t regexp;
	180
215e76c7 ES	181	if (*arg == '^') {
	182	anchor = 1;
	183	arg++;
	184	}
	185
13b8f68c TR	186	assert(*arg == ':');
	187	term = arg+1;
	188	while (term && term != ':') {
	189	if (term == '\\' && (term+1))
	190	term++;
	191	term++;
	192	}
	193	if (term == arg+1)
	194	return NULL;
	195	if (!begin) /* skip_range_arg case */
	196	return term;
	197
	198	pattern = xstrndup(arg+1, term-(arg+1));
	199
1ce761a5 ES	200	anchor--; /* input is in human terms */
1ce761a5 ES	201	start = nth_line_cb(cb_data, anchor);
13b8f68c	202
80e03855	203	drv = userdiff_find_by_path(istate, path);
13b8f68c TR	204	if (drv && drv->funcname.pattern) {
13b8f68c TR	205	const struct userdiff_funcname *pe = &drv->funcname;
ca56dadb	206	CALLOC_ARRAY(xecfg, 1);
13b8f68c TR	207	xdiff_set_find_func(xecfg, pe->pattern, pe->cflags);
	208	}
	209
	210	reg_error = regcomp(&regexp, pattern, REG_NEWLINE);
	211	if (reg_error) {
	212	char errbuf[1024];
	213	regerror(reg_error, &regexp, errbuf, 1024);
	214	die("-L parameter '%s': %s", pattern, errbuf);
	215	}
	216
	217	p = find_funcname_matching_regexp(xecfg, (char*) start, &regexp);
	218	if (!p)
1ce761a5 ES	219	die("-L parameter '%s' starting at line %ld: no match",
1ce761a5 ES	220	pattern, anchor + 1);
13b8f68c TR	221	*begin = 0;
	222	while (p > nth_line_cb(cb_data, *begin))
	223	(*begin)++;
	224
	225	if (*begin >= lines)
	226	die("-L parameter '%s' matches at EOF", pattern);
	227
	228	end = begin+1;
	229	while (*end < lines) {
	230	const char bol = nth_line_cb(cb_data, end);
	231	const char eol = nth_line_cb(cb_data, end+1);
	232	if (match_funcname(xecfg, bol, eol))
	233	break;
	234	(*end)++;
	235	}
	236
	237	regfree(&regexp);
	238	free(xecfg);
	239	free(pattern);
	240
	241	/* compensate for 1-based numbering */
	242	(*begin)++;
	243
	244	return term;
	245	}
	246
25ed3412	247	int parse_range_arg(const char *arg, nth_line_fn_t nth_line_cb,
815834e9	248	void *cb_data, long lines, long anchor,
80e03855 NTND	249	long begin, long end,
80e03855 NTND	250	const char path, struct index_state istate)
25ed3412	251	{
3bf65f9e ES	252	begin = end = 0;
3bf65f9e ES	253
815834e9 ES	254	if (anchor < 1)
	255	anchor = 1;
	256	if (anchor > lines)
	257	anchor = lines + 1;
	258
215e76c7	259	if (arg == ':' \|\| (arg == '^' && *(arg + 1) == ':')) {
80e03855 NTND	260	arg = parse_range_funcname(arg, nth_line_cb, cb_data,
	261	lines, anchor, begin, end,
	262	path, istate);
13b8f68c TR	263	if (!arg \|\| *arg)
	264	return -1;
	265	return 0;
	266	}
	267
815834e9	268	arg = parse_loc(arg, nth_line_cb, cb_data, lines, -anchor, begin);
25ed3412 BY	269
	270	if (*arg == ',')
	271	arg = parse_loc(arg + 1, nth_line_cb, cb_data, lines, *begin + 1, end);
	272
	273	if (*arg)
	274	return -1;
	275
3bf65f9e	276	if (begin && end && end < begin) {
35d803bc	277	SWAP(end, begin);
3bf65f9e ES	278	}
3bf65f9e ES	279
25ed3412 BY	280	return 0;
25ed3412 BY	281	}
12da1d1f	282
80e03855	283	const char skip_range_arg(const char arg, struct index_state *istate)
12da1d1f	284	{
215e76c7	285	if (arg == ':' \|\| (arg == '^' && *(arg + 1) == ':'))
80e03855 NTND	286	return parse_range_funcname(arg, NULL, NULL,
	287	0, 0, NULL, NULL,
	288	NULL, istate);
13b8f68c	289
12da1d1f TR	290	arg = parse_loc(arg, NULL, NULL, 0, -1, NULL);
	291
	292	if (*arg == ',')
	293	arg = parse_loc(arg+1, NULL, NULL, 0, 0, NULL);
	294
	295	return arg;
	296	}