[GROOVY-9086] @CompileStatic of closure calls with OWNER_FIRST fail at runtime with ClassCastException

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.5.6
• Fix Version/s: 3.0.0-beta-1, 2.5.7
• Component/s: Static compilation
• Environment: WIndows7, Groovy 2.5.6, Java 8 + 11
• Assignee: Paul King
• Reporter: Andreas Turban
• Created: 16/Apr/19 06:45
• Updated: 20/May/19 07:31
• Resolved: 01/May/19 13:36

Description

The attached script fails with a ClassCastException, when method m2 is annotated with 

 

strategy = Closure.OWNER_FIRST

 but work with 

 

strategy = Closure.DELEGATE_FIRST

 The expected system-out should be 

 

c1Method called

 in both cases. The generated bytecode for closure Test$_test_closure1$_closure2.class contains a call to getDelegate() instead of getOwner() in case of Closure.OWNER_FIRST. But correctly generates code getOwner() in case of Closure.DELEGATE_FIRST.

The resulting ClassCastException at runtime is:

java.lang.ClassCastException: Test$C2 cannot be cast to groovy.lang.Closure
at Test$_test_closure1$_closure2.doCall(TestScript.groovy:28)
at Test$_test_closure1$_closure2.doCall(TestScript.groovy)
at Test.m2(TestScript.groovy:20)
at Test$_test_closure1.doCall(TestScript.groovy:26)
at Test$_test_closure1.doCall(TestScript.groovy)
at Test.m1(TestScript.groovy:8)
at Test.test(TestScript.groovy:25)
at Test$test.call(Unknown Source)
at TestScript.run(TestScript.groovy:42)

The wrong bytecode for case Closure.OWNER_FIRST:

public java.lang.Object doCall(java.lang.Object);
descriptor: (Ljava/lang/Object;)Ljava/lang/Object;
flags: ACC_PUBLIC
Code:
stack=1, locals=2, args_size=2
0: aload_0
1: checkcast #2 // class Test$_test_closure1$_closure2
4: invokevirtual #29 // Method getDelegate:()Ljava/lang/Object;
7: checkcast #4 // class groovy/lang/Closure
10: invokevirtual #30 // Method groovy/lang/Closure.getDelegate:()Ljava/lang/Object;
13: checkcast #32 // class Test$C1
16: invokevirtual #36 // Method Test$C1.c1Method:()V
19: aconst_null
20: areturn

The correct bytecode for case Closure.DELEGATE_FIRST:

public java.lang.Object doCall(java.lang.Object);
descriptor: (Ljava/lang/Object;)Ljava/lang/Object;
flags: ACC_PUBLIC
Code:
stack=1, locals=2, args_size=2
0: aload_0
1: checkcast #2 // class Test$_test_closure1$_closure2
4: invokevirtual #29 // Method getOwner:()Ljava/lang/Object;
7: checkcast #4 // class groovy/lang/Closure
10: invokevirtual #32 // Method groovy/lang/Closure.getDelegate:()Ljava/lang/Object;
13: checkcast #34 // class Test$C1
16: invokevirtual #38 // Method Test$C1.c1Method:()V
19: aconst_null
20: areturn

Issue Links

• links to: GitHub Pull Request #917