diff -ur mscgen-0.20.old/src/language.y mscgen-0.20/src/language.y

--- mscgen-0.20.old/src/language.y	2016-07-25 10:59:11.000000000 +0000

+++ mscgen-0.20/src/language.y	2016-07-25 11:36:33.608945391 +0000

@@ -39,16 +39,13 @@

 /* Use verbose error reporting such that the expected token names are dumped */

 #define YYERROR_VERBOSE

-/* Name of parameter that is passed to yyparse() */

-#define YYPARSE_PARAM yyparse_result

-

 #define YYMALLOC malloc_s

 /* yyerror

  *  Error handling function.  The TOK_XXX names are substituted for more

  *  understandable values that make more sense to the user.

  */

-void yyerror(const char *str)

+void yyerror( void *yyparse_result, const char *str)

 {

     static const char *tokNames[] = { "TOK_OCBRACKET",          "TOK_CCBRACKET",

                                       "TOK_OSBRACKET",          "TOK_CSBRACKET",

@@ -224,6 +221,8 @@

 %}

+%parse-param { void *yyparse_result}

+

 %token TOK_STRING TOK_QSTRING TOK_EQUAL TOK_COMMA TOK_SEMICOLON TOK_OCBRACKET TOK_CCBRACKET

        TOK_OSBRACKET TOK_CSBRACKET TOK_MSC

        TOK_ATTR_LABEL TOK_ATTR_URL TOK_ATTR_ID TOK_ATTR_IDURL