[GROOVY-4320] Joint compiler + @Delegate fail to recognize method signature with default value

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.7.4
• Fix Version/s: 4.0.0-beta-1, 2.5.16, 3.0.10
• Component/s: Compiler
• Environment: MacOSX Snow Leopard, Groovy 1.7.4, Java 1.6.0_17
• Assignee: Eric Milles
• Reporter: Andres Almiray
• Created: 23/Jul/10 09:09
• Updated: 22/Feb/22 03:12
• Resolved: 18/May/21 00:42

Description

Spotted this problem when upgrading Griffon to Groovy 1.7.4.

Start with a base contract defined in java

import java.util.List;
public interface IApp {
    void event(String name);
    void event(String name, List params);
}

Implement said contract in Groovy

class BaseApp implements IApp {
    private IApp appDelegate
    BaseApp(IApp app) {
        this.appDelegate = app
    }
    void event(String name, List params = []) {
        // empty
    }
}

Now create a Groovy class where the previous will be used as delegate

class RealApp {
    @Delegate BaseApp _base
    RealApp() {
        _base = new BaseApp(this)
    }
}

Compile the code

groovyc IApp.java BaseApp.groovy RealApp.groovy

With Groovy 1.7.3 you get the following method signatures

$ javap BaseApp | grep event
    public void event(java.lang.String, java.util.List);
    public void event(java.lang.String);
$ javap RealApp | grep event
    public void event(java.lang.String);
    public void event(java.lang.String, java.util.List);

However 1.7.4 fails to recognize that the second argument to event() has a default value

$ groovy -version
Groovy Version: 1.7.4 JVM: 1.6.0_17
$ groovyc IApp.java BaseApp.groovy RealApp.groovy 
org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
RealApp.groovy: 1: Can't have an abstract method in a non-abstract class. The class 'RealApp' must be declared abstract or the method 'void event(java.lang.String)' must be implemented.
 @ line 1, column 1.
   class RealApp {
   ^

1 error

Issue Links

• relates to: GROOVY-3683 groovyc can't joint compile a Java class that uses a delegate method from a Groovy class with an @Delegate property annotation