Avoid function pointer cast to preserve ability to do CFI

Author: ndossche

ext/xml/expat_compat.h

@@ -47,6 +47,8 @@
 
 typedef xmlChar XML_Char;
 
+typedef struct XML_Parser_Struct *XML_Parser;
+
 typedef void (*XML_StartElementHandler)(void *, const XML_Char *, const XML_Char **);
 typedef void (*XML_EndElementHandler)(void *, const XML_Char *);
 typedef void (*XML_CharacterDataHandler)(void *, const XML_Char *, int);
@@ -55,7 +57,7 @@ typedef void (*XML_CommentHandler)(void *, const XML_Char *);
 typedef void (*XML_DefaultHandler)(void *, const XML_Char *, int);
 typedef void (*XML_UnparsedEntityDeclHandler)(void *, const XML_Char *, const XML_Char *, const XML_Char *, const XML_Char *, const XML_Char *);
 typedef void (*XML_NotationDeclHandler)(void *, const XML_Char *, const XML_Char *, const XML_Char *, const XML_Char *);
-typedef int  (*XML_ExternalEntityRefHandler)(void *, const XML_Char *, const XML_Char *, const XML_Char *, const XML_Char *);
+typedef int  (*XML_ExternalEntityRefHandler)(XML_Parser, const XML_Char *, const XML_Char *, const XML_Char *, const XML_Char *);
 typedef void (*XML_StartNamespaceDeclHandler)(void *, const XML_Char *, const XML_Char *);
 typedef void (*XML_EndNamespaceDeclHandler)(void *, const XML_Char *);
 
@@ -65,7 +67,7 @@ typedef struct XML_Memory_Handling_Suite {
   void (*free_fcn)(void *ptr);
 } XML_Memory_Handling_Suite;
 
-typedef struct XML_Parser_Struct {
+struct XML_Parser_Struct {
 	int use_namespace;
 
 	xmlChar *_ns_separator;
@@ -84,7 +86,7 @@ typedef struct XML_Parser_Struct {
 	XML_ExternalEntityRefHandler     h_external_entity_ref;
 	XML_StartNamespaceDeclHandler    h_start_ns;
 	XML_EndNamespaceDeclHandler      h_end_ns;
-} *XML_Parser;
+};
 
 enum XML_Error {
 	XML_ERROR_NONE,

ext/xml/xml.c

@@ -919,10 +919,10 @@ void xml_notationDeclHandler(void *userData, const XML_Char *notationName,
 /* }}} */
 
 /* {{{ xml_externalEntityRefHandler() */
-int xml_externalEntityRefHandler(XML_Parser parserPtr, const XML_Char *openEntityNames,
+int xml_externalEntityRefHandler(XML_Parser userData, const XML_Char *openEntityNames,
 	const XML_Char *base, const XML_Char *systemId, const XML_Char *publicId)
 {
-	xml_parser *parser = XML_GetUserData(parserPtr);
+	xml_parser *parser = XML_GetUserData(userData);
 
 	if (!parser || !ZEND_FCC_INITIALIZED(parser->externalEntityRefHandler)) {
 		return 0;
@@ -1296,7 +1296,7 @@ XML_SET_HANDLER_PHP_FUNCTION(xml_set_processing_instruction_handler, processingI
 XML_SET_HANDLER_PHP_FUNCTION(xml_set_default_handler, defaultHandler, XML_SetDefaultHandler, xml_defaultHandler);
 XML_SET_HANDLER_PHP_FUNCTION(xml_set_unparsed_entity_decl_handler, unparsedEntityDeclHandler, XML_SetUnparsedEntityDeclHandler, xml_unparsedEntityDeclHandler);
 XML_SET_HANDLER_PHP_FUNCTION(xml_set_notation_decl_handler, notationDeclHandler, XML_SetNotationDeclHandler, xml_notationDeclHandler);
-XML_SET_HANDLER_PHP_FUNCTION(xml_set_external_entity_ref_handler, externalEntityRefHandler, XML_SetExternalEntityRefHandler, (void *) xml_externalEntityRefHandler);
+XML_SET_HANDLER_PHP_FUNCTION(xml_set_external_entity_ref_handler, externalEntityRefHandler, XML_SetExternalEntityRefHandler, xml_externalEntityRefHandler);
 XML_SET_HANDLER_PHP_FUNCTION(xml_set_start_namespace_decl_handler, startNamespaceDeclHandler, XML_SetStartNamespaceDeclHandler, xml_startNamespaceDeclHandler);
 XML_SET_HANDLER_PHP_FUNCTION(xml_set_end_namespace_decl_handler, endNamespaceDeclHandler, XML_SetEndNamespaceDeclHandler, xml_endNamespaceDeclHandler);