[GROOVY-6401] @CompileStatic type inference bug with overridden methods: causes GroovyCastException at runtime

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 2.1.8
• Fix Version/s: 2.1.9, 2.2.0-rc-2
• Assignee: Cédric Champeau
• Reporter: Lari Hotari
• Created: 23/Oct/13 22:58
• Updated: 29/Oct/13 16:35
• Resolved: 24/Oct/13 08:31

Description

import groovy.transform.CompileStatic

@CompileStatic
interface Greeter {
   public void sayHello()
}

@CompileStatic
class HelloGreeter implements Greeter {
   public void sayHello() {
       println "Hello world!"
   }
}

@CompileStatic
class A {
   Greeter createGreeter() {
       new HelloGreeter()
   }
   
   void sayHello() {
      // also fails: def greeter = createGreeter()
      // successfull: def greeter = (Greeter)createGreeter()
      Greeter greeter = createGreeter()
      greeter.sayHello()
   }   
}

@CompileStatic
class HelloThereGreeter implements Greeter {
   public void sayHello() {
       println "Hello there!"
   }
}

@CompileStatic
class B extends A {
   Greeter createGreeter() {
       new HelloThereGreeter()
   }
}


new B().sayHello()

Throws exception

Exception thrown
loka 24, 2013 6:53:33 AP. org.codehaus.groovy.runtime.StackTraceUtils sanitize
WARNING: Sanitizing stacktrace:
org.codehaus.groovy.runtime.typehandling.GroovyCastException: Cannot cast object 'HelloThereGreeter@5a0e8a14' with class 'HelloThereGreeter' to class 'HelloGreeter'
	at org.codehaus.groovy.runtime.typehandling.DefaultTypeTransformation.castToType(DefaultTypeTransformation.java:360)
	at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.castToType(ScriptBytecodeAdapter.java:599)
	at A.sayHello(flowtyping_bug.groovy:24)
	at A$sayHello.call(Unknown Source)
	at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:45)
	at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:108)
	at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:112)
	at flowtyping_bug.run(flowtyping_bug.groovy:44)
	at groovy.lang.GroovyShell.runScriptOrMainOrTestOrRunnable(GroovyShell.java:257)
	at groovy.lang.GroovyShell.run(GroovyShell.java:481)
	at groovy.lang.GroovyShell.run(GroovyShell.java:163)
	at groovy.lang.GroovyShell$run$0.call(Unknown Source)
	at groovy.ui.Console$_runScriptImpl_closure17.doCall(Console.groovy:954)
	at groovy.ui.Console$_runScriptImpl_closure17.doCall(Console.groovy)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	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:909)
	at groovy.lang.Closure.call(Closure.java:411)
	at groovy.lang.Closure.call(Closure.java:405)
	at groovy.lang.Closure.run(Closure.java:492)
	at java.lang.Thread.run(Thread.java:744)

org.codehaus.groovy.runtime.typehandling.GroovyCastException: Cannot cast object 'HelloThereGreeter@5a0e8a14' with class 'HelloThereGreeter' to class 'HelloGreeter'
	at A.sayHello(flowtyping_bug.groovy:24)
	at A$sayHello.call(Unknown Source)
	at flowtyping_bug.run(flowtyping_bug.groovy:44)