allan.jacobs@Eng 1996-12-18

The code below is probably not valid java, though the spec does
not explicitly forbid what it is doing. However, javac does generate
a class file. Interpreting the class file causes a seg fault.

algol% cat c0914101.java

interface I{
  int i = (new X()).f(); // Forward reference
  int j = 3;
  int f();
}

class X implements I{

  public int f()
   {
     return 3;
   }
   
  public static void check_interface()
   {
   
     System.out.println( i == 3);
     System.out.println( j == 3);
   }
 
  public static void main(String[] arg)
   {
     check_interface();
     
     System.out.println("c0914101");
   }
}
algol% javac -d . c0914101.java
algol% java -verify X
SIGSEGV 11* segmentation violation
    si_signo [11]: SIGSEGV 11* segmentation violation
    si_errno [0]: Error 0
    si_code [1]: SEGV_ACCERR [addr: 0x0]

stackbase=EFFFF77C, stackpointer=EFFFF370

Full thread dump:
    "Finalizer thread" (TID:0xee300418, sys_thread_t:0xef2e0de0, state:R) prio=1
    "Async Garbage Collector" (TID:0xee3003d0, sys_thread_t:0xef310de0, state:R) prio=1
    "Idle thread" (TID:0xee300388, sys_thread_t:0xef340de0, state:R) prio=0
    "clock handler" (TID:0xee300200, sys_thread_t:0xef370de0, state:CW) prio=11
    "main" (TID:0xee3001c0, sys_thread_t:0x367c8, state:R) prio=5 *current thread*
I.<clinit>(c0914101.java:3)
Monitor Cache Dump:
java.lang.Class@EE303210/EE34D508 (key=0xee303210): monitor owner 367c8: "main"
java.lang.Class@EE303220/EE34D578 (key=0xee303220): monitor owner 367c8: "main"
Registered Monitor Dump:
    Finalize me queue lock: unowned
    Thread queue lock: unowned
    Verifier lock: unowned
    Name and type hash table lock: unowned
    String intern lock: unowned
    JNI global reference lock: unowned
    BinClass lock: unowned
    Class loading lock: unowned
    Java stack lock: unowned
    Code rewrite lock: unowned
    Heap lock: unowned
    Has finalization queue lock: unowned
    Monitor IO lock: unowned
    Child death monitor: unowned
    Event monitor: unowned
    I/O monitor: unowned
    Alarm monitor: unowned
Waiting to be notified:
"clock handler"
    Sbrk lock: unowned
    Monitor cache expansion lock: unowned
    Monitor registry: monitor owner 367c8: "main"
Thread Alarm Q:
Abort