Bug ID: JDK-8016320 Method reference in subinterface of type I.super::foo produces exception at runtime

Type: Bug
Component: tools
Sub-Component: javac
Affected Version: 8

Priority: P3
Status: Closed
Resolution: Fixed
OS: generic
CPU: generic

Submitted: 2013-06-11
Updated: 2025-07-31
Resolved: 2013-10-11

JDK 8
8 b113Fixed

Java produces the following Exception at runtime:

Exception in thread "main" java.lang.ClassFormatError: Method lambda$0$bridge in class x/T has illegal modifiers: 0x1000

Testcase:

package x;

interface SAM {
    int m();
}

interface SuperI {
    public default int foo() { return 0; }
}

interface I extends SuperI {
}

interface T extends I {
    public default void boo() { SAM s = I.super::foo; }
}

public class lmbd04804m0  {
    public static void main(String argv[]) {
        new T(){};
    }
}

URL: http://hg.openjdk.java.net/jdk8/jdk8/langtools/rev/1ce8405af5fe User: lana Date: 2013-10-22 16:31:57 +0000
22-10-2013
URL: http://hg.openjdk.java.net/jdk8/tl/langtools/rev/1ce8405af5fe User: rfield Date: 2013-10-11 06:27:40 +0000
11-10-2013
As expected, still reproduces. The "private" fixes are coming down the pike.
01-10-2013
Please set it to PUBLIC until private interface methods are supported.
26-08-2013
The VM code expects exactly on of ACC_PUBLIC and ACC_PRIVATE to be set. This was based on the following. ------ http://cr.openjdk.java.net/~dlsmith/jsr335-0.6.2.html#J says Methods of interfaces may set any of the flags in Table 4.5 except ACC_PROTECTED, ACC_FINAL, ACC_NATIVE, and ACC_SYNCHRONIZED (9.4); they must have exactly one of the ACC_PUBLIC or ACC_PRIVATE flags set. ------- T is an interface and int lambda$0$bridge() does not specify either of ACC_PRIVATE or ACC_PUBLIC
26-08-2013
We can certainly update the compiler to set the PRIVATE bit on this method. That's an easy fix. Separately, we should consider what the spec should say, and then adjust the VM to be consistent with that.
26-08-2013
Here's the specified behavior: ACC_SYNTHETIC was allowed in 7, and has not been prohibited in 8. "All interface methods must have their ACC_ABSTRACT and ACC_PUBLIC flags set; they may have their ACC_VARARGS, ACC_BRIDGE and ACC_SYNTHETIC flags set and must not have any of the other flags in Table 4.5 set (JLS §9.4)." http://docs.oracle.com/javase/specs/jvms/se7/html/jvms-4.html#jvms-4.6
21-08-2013
javap output: int lambda$0$bridge(); descriptor: ()I flags: ACC_SYNTHETIC Code: stack=1, locals=1, args_size=1 0: aload_0 1: invokespecial #2 // InterfaceMethod I.foo:()I 4: ireturn LineNumberTable: line 13: 0 It appears that it is the SYNTHETIC flag appearing on an interface method that the VM is complaining about?
21-08-2013
The following tests are also affected: lang/LMBD/lmbd073/lmbd07302m11/lmbd07302m11.html lang/LMBD/lmbd073/lmbd07302m2/lmbd07302m2.html RULE lang/LMBD/lmbd073/lmbd07302m11/lmbd07302m11_rt Exception java.lang.ClassFormatError RULE lang/LMBD/lmbd073/lmbd07302m2/lmbd07302m2_rt Exception java.lang.ClassFormatError
30-07-2013
The following JCK tests were added for this case: lang/LMBD/lmbd048/lmbd04803m0/lmbd04803m0.html lang/LMBD/lmbd048/lmbd04803m01/lmbd04803m01.html RULE lang/LMBD/lmbd048/lmbd04803m0/lmbd04803m0_rt Exception java.lang.ClassFormatError RULE lang/LMBD/lmbd048/lmbd04803m01/lmbd04803m01_rt Exception java.lang.ClassFormatError
30-07-2013
Reproduces with latest TL
22-07-2013
RULE lang/LMBD/lmbd048/lmbd04803m0/lmbd04803m0 any any RULE lang/LMBD/lmbd048/lmbd04803m01/lmbd04803m01 any any RULE lang/LMBD/lmbd073/lmbd07302m11/lmbd07302m11 any any RULE lang/LMBD/lmbd073/lmbd07302m2/lmbd07302m2 any any
18-07-2013
Yes reproducible with b92 and b93
11-06-2013

Blocks :	JDK-8012557 - Implement lambda methods on interfaces as private
Duplicate :	JDK-8032610 - regression test for 8026022