[antlr-interest] rule return value not declared

[Kendall Shaw]

Hi,

This is a toy example, but it shows a problem I'm having. Is it a bug,
or am I doing something wrong? I want to use the text matched by
expr_sub to modify objects created by actions in that rule, so I do
that in the expr rule ($e.text). The result is that the return
attribute "list" is not declared in the resulting parser:


grammar test;

tokens {
    THING = 'thing' ;
    LP = '(' ;
    RP = ')' ;
    OR = '|' ;
}
@header {
import java.util.ArrayList;
import java.util.List;
}
expr[List<List<String>> ll]
    : e=expr_sub { $e.list.add($e.text); ll.add($e.list); }
    ;

expr_sub returns [List<String> list]
    @init { list = new ArrayList<String>(); }
    : (t=thingy { list.add($t.name); })+
    ;

thingy returns [String name]
    @init { name = ""; }
    : THING LP (NAME { name = $NAME.text; })? RP
    ;

NAME : ('a'..'z')+ ;


The code generated for expr_sub, see that "list" is not declared:


    public static class expr_sub_return extends ParserRuleReturnScope {
        public List<String> list;
    };

    // $ANTLR start "expr_sub"
    // test.g:17:1: expr_sub returns [List<String> list] : (t= thingy )+ ;
    public final testParser.expr_sub_return expr_sub() throws RecognitionException {
        testParser.expr_sub_return retval = new testParser.expr_sub_return();
        retval.start = input.LT(1);

        String t = null;


         list = new ArrayList<String>(); 
        try {
            // test.g:19:5: ( (t= thingy )+ )
            // test.g:19:7: (t= thingy )+
            {
            // test.g:19:7: (t= thingy )+
            int cnt1=0;
            loop1:
            do {
                int alt1=2;
                int LA1_0 = input.LA(1);

                if ( (LA1_0==THING) ) {
                    alt1=1;
                }


                switch (alt1) {
            	case 1 :
            	    // test.g:19:8: t= thingy
            	    {
            	    pushFollow(FOLLOW_thingy_in_expr_sub109);
            	    t=thingy();

            	    state._fsp--;

            	     list.add(t); 

            	    }
            	    break;

            	default :
            	    if ( cnt1 >= 1 ) break loop1;
                        EarlyExitException eee =
                            new EarlyExitException(1, input);
                        throw eee;
                }
                cnt1++;
            } while (true);


            }

            retval.stop = input.LT(-1);

        }
        catch (RecognitionException re) {
            reportError(re);
            recover(input,re);
        }
        finally {
        }
        return retval;
    }