[GROOVY-8758] @WithReadLock in inner class of @CompileStatic class causes java.lang.VerifyError

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.5.2
• Fix Version/s: 3.0.0-alpha-4, 2.5.3
• Component/s: bytecode, Static compilation
• Environment: Ubuntu 18.04 x86_64, OpenJDK 10
• Assignee: Paul King
• Reporter: Curtis Mackie
• Created: 20/Aug/18 23:08
• Updated: 13/Dec/18 10:05
• Resolved: 23/Aug/18 03:41

Description

Minimal reproduction:

import groovy.transform.CompileStatic
import groovy.transform.WithReadLock

@CompileStatic
class A {
    private class B {
        @WithReadLock
        int getFoo() {
            0
        }
    }

    private B b

    A() {
        b = new B()
    }
}

def a = new A()

Output from groovy:

Caught: java.lang.VerifyError: Bad type on operand stack
Exception Details:
  Location:
    A$B.getFoo()I @4: invokevirtual
  Reason:
    Type 'A' (current frame, stack[0]) is not assignable to 'java/util/concurrent/locks/ReentrantReadWriteLock$ReadLock'
  Current Frame:
    bci: @4
    flags: { }
    locals: { 'A$B' }
    stack: { 'A' }
  Bytecode:
    0x0000000: 2ab4 0015 b600 2d01 5703 3c00 2ab4 0015
    0x0000010: b600 3001 5700 1bac 0000 bf00 0000 0000
    0x0000020: 0000 0000 0000 00bf 4d2a b400 15b6 0030
    0x0000030: 0157 2cbf 0000 bf                      
  Exception Handler Table:
    bci [9, 12] => handler: 40
    bci [22, 24] => handler: 40
  Stackmap Table:
    full_frame(@24,{},{Object[#51]})
    same_locals_1_stack_item_frame(@27,Object[#51])
    full_frame(@40,{Object[#2]},{Object[#51]})
    full_frame(@52,{},{Object[#51]})

java.lang.VerifyError: Bad type on operand stack
Exception Details:
  Location:
    A$B.getFoo()I @4: invokevirtual
  Reason:
    Type 'A' (current frame, stack[0]) is not assignable to 'java/util/concurrent/locks/ReentrantReadWriteLock$ReadLock'
  Current Frame:
    bci: @4
    flags: { }
    locals: { 'A$B' }
    stack: { 'A' }
  Bytecode:
    0x0000000: 2ab4 0015 b600 2d01 5703 3c00 2ab4 0015
    0x0000010: b600 3001 5700 1bac 0000 bf00 0000 0000
    0x0000020: 0000 0000 0000 00bf 4d2a b400 15b6 0030
    0x0000030: 0157 2cbf 0000 bf                      
  Exception Handler Table:
    bci [9, 12] => handler: 40
    bci [22, 24] => handler: 40
  Stackmap Table:
    full_frame(@24,{},{Object[#51]})
    same_locals_1_stack_item_frame(@27,Object[#51])
    full_frame(@40,{Object[#2]},{Object[#51]})
    full_frame(@52,{},{Object[#51]})

    at A.<init>(test.groovy:16)
    at test.run(test.groovy:20)

From a glance at the bytecode, it looks like Groovy is creating the $reentrantlock field in A$B as it should, but in the actual method it tries to use this$0 (i.e. the reference to the enclosing outer A object) as a ReentrantReadWriteLock instead.

This error also occurs with @WithWriteLock, but doesn't occur with @Synchronized.

Issue Links

• links to: GitHub Pull Request #787