[antlr-interest] Bug? Invalid Java code generated

[Sam Barnett-Cormack]

Hi all

The attached grammar (which you're probably all tired of) generates Java 
code with an error in. I've checked, and the error isn't in a copy 
action or predicate - it's in the expansion of $text in a parser 
predicate. I don't know if I've used $text incorrectly, because I'm 
using it as I understand the documentation says to (including the ANTLR 
book).

The error is:

retval cannot be resolved

on: ASN_1Parser.java
line: line 17279

The generated function in question is:

// $ANTLR start synpred26_ASN_1
     public final void synpred26_ASN_1_fragment() throws 
RecognitionException {
         // /home/sdb/workspace/asn.1-parse/grammars/ASN_1.g:583:44: ( 
nameForm {...}?)
         // /home/sdb/workspace/asn.1-parse/grammars/ASN_1.g:583:44: 
nameForm {...}?
         {
         pushFollow(FOLLOW_nameForm_in_synpred26_ASN_13890);
         nameForm();

         state._fsp--;
         if (state.failed) return ;
         if ( 
!((isStandardOIDName(input.toString(retval.start,input.LT(-1))))) ) {
             if (state.backtracking>0) {state.failed=true; return ;}
             throw new FailedPredicateException(input, 
"synpred26_ASN_1", "isStandardOIDName($text)");
         }

         }
     }
// $ANTLR end synpred26_ASN_1

The rule from the grammar (whole thing attached) is:

objIdComponents options{backtrack=true;} : nameForm 
{isStandardOIDName($text)}? | numberForm | nameAndNumberForm | 
definedValue ;

If this isn't a bug, can someone explain how to pass a function called 
in a predicate the text matched so far? If this is a bug, anyone have a 
workaround? Please. Thanks!

Sam

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