[GROOVY-5051] 'this' uses in a superclass is treated as subclass, preventing acces to private members

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.8.2, 2.4.0-rc-1
• Fix Version/s: 5.0.0-alpha-1
• Component/s: groovy-runtime
• Assignee: Eric Milles
• Reporter: Wujek
• Created: 28/Sep/11 12:54
• Updated: 23/Aug/23 09:11
• Resolved: 14/Jul/23 19:05

Description

The original thread: http://groovy.329449.n5.nabble.com/Currying-an-instance-method-exception-with-modifier-private-td4849071.html

The following code explains the issue:

class Base {

    private __value(arg) { println "$arg" } // <<< here
    def value = this.&__value.curry('value')
    def extend() {
        def tmp = this.&__value.curry('extend')
        tmp()
    }
}

class Sub extends Base {

    def test() {
        value()
        extend()
    }
}

new Sub().test()

Exception thrown

Sep 28, 2011 6:41:42 PM org.codehaus.groovy.runtime.StackTraceUtils sanitize
WARNING: Sanitizing stacktrace:
java.lang.IllegalArgumentException: Can't curry 1 arguments for a closure with 0 parameters.
	at org.codehaus.groovy.runtime.CurriedClosure.<init>(CurriedClosure.java:72)
	at org.codehaus.groovy.runtime.CurriedClosure.<init>(CurriedClosure.java:86)
	at groovy.lang.Closure.curry(Closure.java:527)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.codehaus.groovy.runtime.callsite.PogoMetaMethodSite$PogoCachedMethodSite.invoke(PogoMetaMethodSite.java:226)
	at org.codehaus.groovy.runtime.callsite.PogoMetaMethodSite.call(PogoMetaMethodSite.java:64)
	at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:42)
	at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:108)
	at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:116)
	at Base.<init>(ConsoleScript7:4)
	at Sub.<init>(ConsoleScript7)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
	at org.codehaus.groovy.reflection.CachedConstructor.invoke(CachedConstructor.java:77)
	at org.codehaus.groovy.runtime.callsite.ConstructorSite$ConstructorSiteNoUnwrapNoCoerce.callConstructor(ConstructorSite.java:102)
	at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCallConstructor(CallSiteArray.java:54)
	at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callConstructor(AbstractCallSite.java:182)
	at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callConstructor(AbstractCallSite.java:186)
	at ConsoleScript7.run(ConsoleScript7:19)
	at groovy.lang.GroovyShell.runScriptOrMainOrTestOrRunnable(GroovyShell.java:266)
	at groovy.lang.GroovyShell.run(GroovyShell.java:517)
	at groovy.lang.GroovyShell.run(GroovyShell.java:172)
	at groovy.lang.GroovyShell$run.call(Unknown Source)
	at groovy.ui.Console$_runScriptImpl_closure16.doCall(Console.groovy:924)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:90)
	at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:233)
	at org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:272)
	at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:883)
	at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.callCurrent(PogoMetaClassSite.java:66)
	at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:141)
	at groovy.ui.Console$_runScriptImpl_closure16.doCall(Console.groovy)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:90)
	at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:233)
	at org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:272)
	at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:883)
	at groovy.lang.Closure.call(Closure.java:410)
	at groovy.lang.Closure.call(Closure.java:404)
	at groovy.lang.Closure.run(Closure.java:488)
	at java.lang.Thread.run(Thread.java:662)

java.lang.IllegalArgumentException: Can't curry 1 arguments for a closure with 0 parameters.
	at Base.<init>(ConsoleScript7:4)
	at Sub.<init>(ConsoleScript7)
	at ConsoleScript7.run(ConsoleScript7:19)

The only change it needs is to change the private to def / protected in the line marked with '// <<<'.

Similar Java code behaves correctly:

class Base {

	private int get() {
		return 17;
	}

	int a = this.get(); // <<< here

	public void test() {
		System.out.println(a);
	}
}

public class Sub extends Base {

	public static void main(String[] args) {
		new Sub().test();
	}
}

When Sub is instantiated, the call to the private get() is done in the superclass, who can access it.

Issue Links

• is related to: GROOVY-2433 Closure in base class unable to call private methods when invoked from derived class
• relates to: GROOVY-10568 MissingMethodException using method-pointer operator in superclass
• relates to: GROOVY-11128 implicit-this access within closure to private members in declaring class when invoked from derived class