git

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#include "git-compat-util.h"
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#include "line-range.h"
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#include "xdiff-interface.h"
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#include "userdiff.h"
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/*
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 * Parse one item in the -L option
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 *
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 * 'begin' is applicable only to relative range anchors. Absolute anchors
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 * ignore this value.
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 *
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 * When parsing "-L A,B", parse_loc() is called once for A and once for B.
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 *
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 * When parsing A, 'begin' must be a negative number, the absolute value of
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 * which is the line at which relative start-of-range anchors should be
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 * based. Beginning of file is represented by -1.
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 *
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 * When parsing B, 'begin' must be the positive line number immediately
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 * following the line computed for 'A'.
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 */
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static const char *parse_loc(const char *spec, nth_line_fn_t nth_line,
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			     void *data, long lines, long begin, long *ret)
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{
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	char *term;
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	const char *line;
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	long num;
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	int reg_error;
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	regex_t regexp;
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	regmatch_t match[1];
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	/* Allow "-L <something>,+20" to mean starting at <something>
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	 * for 20 lines, or "-L <something>,-5" for 5 lines ending at
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	 * <something>.
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	 */
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	if (1 <= begin && (spec[0] == '+' || spec[0] == '-')) {
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		num = strtol(spec + 1, &term, 10);
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		if (term != spec + 1) {
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			if (!ret)
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				return term;
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			if (num == 0)
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				die("-L invalid empty range");
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			if (spec[0] == '-')
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				num = 0 - num;
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			if (0 < num)
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				*ret = begin + num - 2;
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			else if (!num)
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				*ret = begin;
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			else
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				*ret = begin + num > 0 ? begin + num : 1;
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			return term;
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		}
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		return spec;
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	}
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	num = strtol(spec, &term, 10);
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	if (term != spec) {
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		if (ret) {
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			if (num <= 0)
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				die("-L invalid line number: %ld", num);
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			*ret = num;
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		}
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		return term;
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	}
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	if (begin < 0) {
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		if (spec[0] != '^')
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			begin = -begin;
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		else {
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			begin = 1;
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			spec++;
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		}
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	}
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	if (spec[0] != '/')
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		return spec;
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	/* it could be a regexp of form /.../ */
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	for (term = (char *) spec + 1; *term && *term != '/'; term++) {
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		if (*term == '\\')
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			term++;
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	}
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	if (*term != '/')
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		return spec;
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	/* in the scan-only case we are not interested in the regex */
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	if (!ret)
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		return term+1;
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	/* try [spec+1 .. term-1] as regexp */
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	*term = 0;
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	begin--; /* input is in human terms */
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	line = nth_line(data, begin);
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	if (!(reg_error = regcomp(&regexp, spec + 1, REG_NEWLINE)) &&
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	    !(reg_error = regexec(&regexp, line, 1, match, 0))) {
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		const char *cp = line + match[0].rm_so;
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		const char *nline;
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		while (begin++ < lines) {
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			nline = nth_line(data, begin);
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			if (line <= cp && cp < nline)
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				break;
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			line = nline;
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		}
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		*ret = begin;
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		regfree(&regexp);
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		*term++ = '/';
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		return term;
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	}
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	else {
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		char errbuf[1024];
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		regerror(reg_error, &regexp, errbuf, 1024);
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		die("-L parameter '%s' starting at line %ld: %s",
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		    spec + 1, begin + 1, errbuf);
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	}
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}
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static int match_funcname(xdemitconf_t *xecfg, const char *bol, const char *eol)
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{
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	if (xecfg) {
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		char buf[1];
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		return xecfg->find_func(bol, eol - bol, buf, 1,
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					xecfg->find_func_priv) >= 0;
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	}
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	if (bol == eol)
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		return 0;
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	if (isalpha(*bol) || *bol == '_' || *bol == '$')
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		return 1;
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	return 0;
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}
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static const char *find_funcname_matching_regexp(xdemitconf_t *xecfg, const char *start,
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						 regex_t *regexp)
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{
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	int reg_error;
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	regmatch_t match[1];
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	while (*start) {
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		const char *bol, *eol;
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		reg_error = regexec(regexp, start, 1, match, 0);
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		if (reg_error == REG_NOMATCH)
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			return NULL;
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		else if (reg_error) {
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			char errbuf[1024];
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			regerror(reg_error, regexp, errbuf, 1024);
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			die("-L parameter: regexec() failed: %s", errbuf);
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		}
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		/* determine extent of line matched */
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		bol = start+match[0].rm_so;
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		eol = start+match[0].rm_eo;
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		while (bol > start && *--bol != '\n')
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			; /* nothing */
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		if (*bol == '\n')
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			bol++;
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		while (*eol && *eol != '\n')
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			eol++;
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		if (*eol == '\n')
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			eol++;
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		/* is it a funcname line? */
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		if (match_funcname(xecfg, (char*) bol, (char*) eol))
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			return bol;
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		start = eol;
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	}
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	return NULL;
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}
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static const char *parse_range_funcname(
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	const char *arg, nth_line_fn_t nth_line_cb,
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	void *cb_data, long lines, long anchor, long *begin, long *end,
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	const char *path, struct index_state *istate)
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{
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	char *pattern;
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	const char *term;
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	struct userdiff_driver *drv;
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	xdemitconf_t *xecfg = NULL;
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	const char *start;
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	const char *p;
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	int reg_error;
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	regex_t regexp;
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	if (*arg == '^') {
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		anchor = 1;
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		arg++;
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	}
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	assert(*arg == ':');
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	term = arg+1;
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	while (*term && *term != ':') {
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		if (*term == '\\' && *(term+1))
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			term++;
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		term++;
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	}
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	if (term == arg+1)
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		return NULL;
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	if (!begin) /* skip_range_arg case */
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		return term;
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	pattern = xstrndup(arg+1, term-(arg+1));
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	anchor--; /* input is in human terms */
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	start = nth_line_cb(cb_data, anchor);
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	drv = userdiff_find_by_path(istate, path);
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	if (drv && drv->funcname.pattern) {
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		const struct userdiff_funcname *pe = &drv->funcname;
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		CALLOC_ARRAY(xecfg, 1);
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		xdiff_set_find_func(xecfg, pe->pattern, pe->cflags);
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	}
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	reg_error = regcomp(&regexp, pattern, REG_NEWLINE);
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	if (reg_error) {
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		char errbuf[1024];
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		regerror(reg_error, &regexp, errbuf, 1024);
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		die("-L parameter '%s': %s", pattern, errbuf);
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	}
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	p = find_funcname_matching_regexp(xecfg, (char*) start, &regexp);
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	if (!p)
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		die("-L parameter '%s' starting at line %ld: no match",
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		    pattern, anchor + 1);
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	*begin = 0;
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	while (p > nth_line_cb(cb_data, *begin))
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		(*begin)++;
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	if (*begin >= lines)
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		die("-L parameter '%s' matches at EOF", pattern);
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	*end = *begin+1;
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	while (*end < lines) {
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		const char *bol = nth_line_cb(cb_data, *end);
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		const char *eol = nth_line_cb(cb_data, *end+1);
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		if (match_funcname(xecfg, bol, eol))
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			break;
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		(*end)++;
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	}
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	regfree(&regexp);
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	if (xecfg)
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		xdiff_clear_find_func(xecfg);
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	free(xecfg);
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	free(pattern);
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	/* compensate for 1-based numbering */
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	(*begin)++;
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	return term;
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}
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int parse_range_arg(const char *arg, nth_line_fn_t nth_line_cb,
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		    void *cb_data, long lines, long anchor,
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		    long *begin, long *end,
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		    const char *path, struct index_state *istate)
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{
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	*begin = *end = 0;
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	if (anchor < 1)
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		anchor = 1;
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	if (anchor > lines)
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		anchor = lines + 1;
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	if (*arg == ':' || (*arg == '^' && *(arg + 1) == ':')) {
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		arg = parse_range_funcname(arg, nth_line_cb, cb_data,
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					   lines, anchor, begin, end,
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					   path, istate);
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		if (!arg || *arg)
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			return -1;
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		return 0;
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	}
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	arg = parse_loc(arg, nth_line_cb, cb_data, lines, -anchor, begin);
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	if (*arg == ',')
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		arg = parse_loc(arg + 1, nth_line_cb, cb_data, lines, *begin + 1, end);
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	if (*arg)
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		return -1;
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	if (*begin && *end && *end < *begin) {
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		SWAP(*end, *begin);
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	}
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	return 0;
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}
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const char *skip_range_arg(const char *arg, struct index_state *istate)
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{
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	if (*arg == ':' || (*arg == '^' && *(arg + 1) == ':'))
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		return parse_range_funcname(arg, NULL, NULL,
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					    0, 0, NULL, NULL,
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					    NULL, istate);
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	arg = parse_loc(arg, NULL, NULL, 0, -1, NULL);
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	if (*arg == ',')
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		arg = parse_loc(arg+1, NULL, NULL, 0, 0, NULL);
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	return arg;
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}
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