[GROOVY-9650] MissingPropertyException when accessing @Log-generated log field from a CGLib-proxied outer class

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.5, 2.5.13
• Fix Version/s: 2.5.14, 3.0.6
• External issue URL: https://github.com/spring-projects/spring-boot/issues/22505
• Assignee: Eric Milles
• Reporter: Andy Wilkinson
• Created: 23/Jul/20 09:23
• Updated: 11/Nov/20 02:01
• Resolved: 25/Sep/20 16:49

Description

There appears to be a regression in Groovy 2.5.13. It can be reproduced with the following script:

import groovy.util.logging.Log
import java.lang.reflect.Method
import java.util.function.Consumer
import net.sf.cglib.proxy.MethodInterceptor
import net.sf.cglib.proxy.MethodProxy
import net.sf.cglib.proxy.Enhancer

@Log
@Grab("cglib:cglib:3.3.0")
class Thing {

	void method() {
		Runnable nested = {
			log.info("hello")
		}
		nested.run()
	}

}

def enhancer = new Enhancer()
enhancer.superclass = Thing
enhancer.callback = { obj, method, args, proxy -> 
    proxy.invokeSuper(obj, args);
} as MethodInterceptor

def proxy = enhancer.create()
proxy.method()

When run with Groovy 2.5.12, hello is logged:

$ sdk use groovy 2.5.12

Using groovy version 2.5.12 in this shell.
$ groovy logging.groovy
Jul 23, 2020 10:20:05 AM java_util_logging_Logger$info$0 call
INFO: hello

With Groovy 2.5.13, the log field cannot be found:

$ sdk use groovy 2.5.13

Using groovy version 2.5.13 in this shell.
$ groovy logging.groovy
Caught: groovy.lang.MissingPropertyException: No such property: log for class: Thing$$EnhancerByCGLIB$$ac2265fe
groovy.lang.MissingPropertyException: No such property: log for class: Thing$$EnhancerByCGLIB$$ac2265fe
	at net.sf.cglib.proxy.MethodProxy$invokeSuper.call(Unknown Source)
	at logging$_run_closure1.doCall(logging.groovy:24)
	at com.sun.proxy.$Proxy16.intercept(Unknown Source)
	at Thing$$EnhancerByCGLIB$$ac2265fe.getProperty(<generated>)
	at Thing$_method_closure1.doCall(logging.groovy:14)
	at Thing$_method_closure1.doCall(logging.groovy)
	at Thing.method(logging.groovy:16)
	at Thing$$EnhancerByCGLIB$$ac2265fe.CGLIB$method$0(<generated>)
	at Thing$$EnhancerByCGLIB$$ac2265fe$$FastClassByCGLIB$$704960d8.invoke(<generated>)
	at net.sf.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228)
	at net.sf.cglib.proxy.MethodProxy$invokeSuper.call(Unknown Source)
	at logging$_run_closure1.doCall(logging.groovy:24)
	at com.sun.proxy.$Proxy16.intercept(Unknown Source)
	at Thing$$EnhancerByCGLIB$$ac2265fe.method(<generated>)
	at Thing$$EnhancerByCGLIB$$ac2265fe$method.call(Unknown Source)
	at logging.run(logging.groovy:28)

The problem does not occur if Thing is not proxied or when trying to access a field that explicit declared rather than being created via @Log.