[antlr-interest] Overriding rule in imported parser grammar generates a faulty java code with undefined method

[Berger, Michael]

Title:

Overriding rule in imported parser grammar generates a faulty java code
with undefined method

 

Description:

 

Simple extended example from the article about the import introduction:

A parser 1 defines a rule that will be override by parser 2 importing
parser 1.

The combined grammar imports the parser 2.

 

Software: 

antlrworks-1.3.1.jar

 

 

-------

 

lexer grammar lex;

 

IntString : 'int' ;

FloatString : 'float' ;

Semicolon : ';' ;

Equal : '=' ;

 

ID : 'a'..'z'+ ;

INT : '0'..'9'+ ;

WS : (' '|'\n')+ {skip();} ;

--------

 

parser grammar par1;

 

type : IntString ;

decl : type ID Semicolon | type ID init Semicolon ;

init : Equal INT ;

---------

 

parser grammar par2;

 

import par1;

 

prog : decl ;

type : IntString | FloatString ; //override from p1

---------

 

grammar gram;

 

import lex, par2;

 

start : decl | init;

--------

 

 

Generated java code (snipped):

 

public class gramParser extends Parser {

 

(...)

                // delegates

    public gram_par2_par1 gpar1;

    public gram_par2 gpar2;

    // delegators

                

(...)

                

                // Delegated rules

    public void decl() throws RecognitionException { gpar1.decl(); }

    public void type() throws RecognitionException { gpar1.type(); } (*)

    public void init() throws RecognitionException { gpar1.init(); }

    public void prog() throws RecognitionException { gpar2.prog(); }

                

(...)

}

 

The part (*) produces the error line:

D:\local\mib\Compiler\de.fraunhofer.fokus.ttcn3.compiler\grammar\gramPar
ser.java:151: cannot find symbol

symbol  : method type()

location: class gram_par2_par1

public void type() throws RecognitionException { gpar1.type(); }

 

 

 

Best regards,

 

Michael Berger

Fraunhofer FOKUS

Kaiserin-Augusta-Allee 31

10589 Berlin

Tel: +49-30-3463-7176