Function xmlFAParseAtom

ThirdParty/libxml2/vtklibxml2/xmlregexp.c:5190–5254

* xmlFAParseAtom: * @ctxt: a regexp parser context * * [9] atom ::= Char | charClass | ( '(' regExp ')' ) */

 * [9]   atom   ::=   Char | charClass | ( '(' regExp ')' )
 */
static int
xmlFAParseAtom(xmlRegParserCtxtPtr ctxt) {
    int codepoint, len;

    codepoint = xmlFAIsChar(ctxt);
    if (codepoint > 0) {
	ctxt->atom = xmlRegNewAtom(ctxt, XML_REGEXP_CHARVAL);
	if (ctxt->atom == NULL)
	    return(-1);
        len = 4;
        codepoint = xmlGetUTF8Char(ctxt->cur, &len);
        if (codepoint < 0) {
            ERROR("Invalid UTF-8");
            return(-1);
        }
	ctxt->atom->codepoint = codepoint;
	NEXTL(len);
	return(1);
    } else if (CUR == '|') {
	return(0);
    } else if (CUR == 0) {
	return(0);
    } else if (CUR == ')') {
	return(0);
    } else if (CUR == '(') {
	xmlRegStatePtr start, oldend, start0;

	NEXT;
        if (ctxt->depth >= 50) {
	    ERROR("xmlFAParseAtom: maximum nesting depth exceeded");
            return(-1);
        }
	/*
	 * this extra Epsilon transition is needed if we count with 0 allowed
	 * unfortunately this can't be known at that point
	 */
	xmlFAGenerateEpsilonTransition(ctxt, ctxt->state, NULL);
	start0 = ctxt->state;
	xmlFAGenerateEpsilonTransition(ctxt, ctxt->state, NULL);
	start = ctxt->state;
	oldend = ctxt->end;
	ctxt->end = NULL;
	ctxt->atom = NULL;
        ctxt->depth++;
	xmlFAParseRegExp(ctxt, 0);
        ctxt->depth--;
	if (CUR == ')') {
	    NEXT;
	} else {
	    ERROR("xmlFAParseAtom: expecting ')'");
	}
	ctxt->atom = xmlRegNewAtom(ctxt, XML_REGEXP_SUBREG);
	if (ctxt->atom == NULL)
	    return(-1);
	ctxt->atom->start = start;
	ctxt->atom->start0 = start0;
	ctxt->atom->stop = ctxt->state;
	ctxt->end = oldend;