Name: vsR10008 Date: 05/30/2000



JVMS 2nd ed. (CHAPTER 3 "The Structure of the Java Virtual Machine", section 3.9
"Specially Named Initialization Methods") reads:

"A class or interface has at most one class or interface initialization method.
...
The initialization method of a class or interface is static and takes no arguments.
It has the special name <clinit>"

Presence of two different <clinit> methods (static and non-static) is allowed because
static <clinit> is class initializer but non-static is not; thus, there is only one
class initializer in this case.

The following test shows that JVM doesn't allow static and non-static <clinit>
to coexist in classfile and is failed with exception java.lang.ClassFormatError:

------------------------------------------------------------------ c.jasm -----

super public class c
{

public static Field a:I;

public Method "<init>":"()V"
stack 1 locals 1
{
aload_0;
invokespecial Method java/lang/Object."<init>":"()V";
return;
}

// It is not a class initializer
Method "<clinit>":"()V"
stack 1 locals 1
{
iconst_1;
putstatic Field a:"I";
return;
}

// class initializer
static Method "<clinit>":"()V"
stack 1 locals 1
{
iconst_2;
putstatic Field a:"I";
return;
}

}

------------------------------------------------------------------ t.java -----

public class t {
    public static void main(String[] argv) {
        try {
            if ( c.a == 2 ) {
                System.out.println("PASSED!");
            } else {
                System.out.println("FAILED, a=" +c.a);
            }
        } catch (Throwable t) {
            System.out.println("FAILED: Exception "+t);
        }
    }
}

--------------------------------------------------------------------------------

$ java -version
java version "1.3.0rc3"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.0rc3-Z)
Java HotSpot(TM) Client VM (build 1.3.0rc3-Z, interpreted mode)

$ uname -a
SunOS novo12 5.7 Generic_Patch sun4u sparc SUNW,Ultra-2

$ jasm c.jasm

$ javac -d . t.java

$ java t

FAILED: Exception java.lang.ClassFormatError: c1 (Repeative method name/signature)

This failure is reproduced in all builds of JDK 1.3 and JDK 1.2-1.2.2
(and affects Classic and HotSpot both).

In JDK 1.1-1.2_Beta4 failure is different: JVM invokes non-static
<clinit> instead of static one (becase it is encountered first)

In JDK 1.0,1.0.1,1.0.2,1.0beta2 this test is passed successfully.

The complete run log (for all available JDKs):

---- 1.0 ----
PASSED!
---- 1.0.1 ----
PASSED!
---- 1.0.2 ----
PASSED!
---- 1.0beta2 ----
PASSED!
---- 1.1_Final ----
FAILED, a=1
---- 1.1.1 ----
FAILED, a=1
---- 1.1.2 ----
FAILED, a=1
---- 1.1.3 ----
FAILED, a=1
---- 1.1.4 ----
FAILED, a=1
---- 1.1.5 ----
FAILED, a=1
---- 1.1.6 ----
FAILED, a=1
---- 1.1.7 ----
FAILED, a=1
---- 1.1.7A ----
FAILED, a=1
---- 1.1.7B ----
FAILED, a=1
---- 1.1.8 ----
FAILED, a=1
---- 1.2_EA2 ----
FAILED, a=1
---- 1.2_Beta1 ----
FAILED, a=1
---- 1.2beta2 ----
FAILED, a=1
---- 1.2beta3 ----
FAILED, a=1
---- 1.2beta4 ----
FAILED, a=1
---- 1.2 ----
FAILED: Exception java.lang.ClassFormatError: c1 (Repeative method name/signature)
---- 1.2.1 ----
FAILED: Exception java.lang.ClassFormatError: c1 (Repeative method name/signature)
---- 1.2.2 ----
FAILED: Exception java.lang.ClassFormatError: c1 (Repeative method name/signature)
---- 1.3beta ----
FAILED: Exception java.lang.ClassFormatError: c1 (Repeative method name/signature)
---- 1.3.0 ----
FAILED: Exception java.lang.ClassFormatError: c1 (Repeative method name/signature)
---- 1.3.0rc2 ----
FAILED: Exception java.lang.ClassFormatError: c1 (Repeative method name/signature)
---- 1.3.0rc3 ----
FAILED: Exception java.lang.ClassFormatError: c1 (Repeative method name/signature)
---- 1.4.0beta ----
FAILED: Exception java.lang.ClassFormatError: c1 (Repeative method name/signature)

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