JDK 8 incorectly processes nameless parameters in MethodParameters Attribute

[Михаил Богданов]

JDK 8 incorrectly processes nameless (name=null) parameters in MethodParameters attribute. Actually problem in inconsistency between Hotspot and reflection:
Hotspot  VM constructs nameless parameter with empty string name that cause Executable.verifyParameters to throw MalformedParametersException.
//Code to reproduce:import jdk.internal.org.objectweb.asm.ClassWriter;
import jdk.internal.org.objectweb.asm.MethodVisitor;
import jdk.internal.org.objectweb.asm.Opcodes;

import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLClassLoader;

public class Bug {

    public static void main(String[] args) throws ClassNotFoundException, NoSuchMethodException {
        ClassWriter writer = new ClassWriter(Opcodes.ASM5);
        writer.visit(Opcodes.V1_8, Opcodes.ACC_PUBLIC | Opcodes.ACC_INTERFACE | Opcodes.ACC_ABSTRACT, "Test", null, "java/lang/Object", null);
        MethodVisitor test = writer.visitMethod(Opcodes.ACC_PUBLIC | Opcodes.ACC_ABSTRACT, "test", "(I)V", null, null);
        test.visitParameter(null, 0);
        test.visitEnd();

        writer.visitEnd();
        final byte[] bytes = writer.toByteArray();

        URLClassLoader urlClassLoader = new URLClassLoader(new URL[0], ClassLoader.getSystemClassLoader()) {
            @Override
            protected Class<?> findClass(String name) throws ClassNotFoundException {
                if (name.equals("Test")) {
                    return defineClass("Test", bytes, 0, bytes.length);
                }
                return super.findClass(name);
            }
        };


        Class<?> clazz = urlClassLoader.loadClass("Test");
        Method method = clazz.getDeclaredMethod("test", Integer.TYPE);
//        Exception in thread "main" java.lang.reflect.MalformedParametersException: Invalid parameter name ""
//        at java.lang.reflect.Executable.verifyParameters(Executable.java:386)
//        at java.lang.reflect.Executable.privateGetParameters(Executable.java:416)
//        at java.lang.reflect.Executable.getParameters(Executable.java:357)
//        at Bug.main(Bug.java:37)
        method.getParameters();
    }
}
Best regards,   Max

[dalibor topic]

Hi Mihail,

could you file an issue at bugs.java.com and let us know which incident
id you receive, please?

cheers,
dalibor topic

Hotspot VM constructs nameless parameter with empty string name that cause Executable.verifyParameters to throw MalformedParametersException.
//Code to reproduce:import jdk.internal.org.objectweb.asm.ClassWriter;
import jdk.internal.org.objectweb.asm.MethodVisitor;
import jdk.internal.org.objectweb.asm.Opcodes;
import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLClassLoader;
public class Bug {
public static void main(String[] args) throws ClassNotFoundException, NoSuchMethodException {
ClassWriter writer = new ClassWriter(Opcodes.ASM5);
writer.visit(Opcodes.V1_8, Opcodes.ACC_PUBLIC | Opcodes.ACC_INTERFACE | Opcodes.ACC_ABSTRACT, "Test", null, "java/lang/Object", null);
MethodVisitor test = writer.visitMethod(Opcodes.ACC_PUBLIC | Opcodes.ACC_ABSTRACT, "test", "(I)V", null, null);
test.visitParameter(null, 0);
test.visitEnd();
writer.visitEnd();
final byte[] bytes = writer.toByteArray();
URLClassLoader urlClassLoader = new URLClassLoader(new URL[0], ClassLoader.getSystemClassLoader()) {
@Override
protected Class<?> findClass(String name) throws ClassNotFoundException {
if (name.equals("Test")) {
return defineClass("Test", bytes, 0, bytes.length);
}
return super.findClass(name);
}
};
Class<?> clazz = urlClassLoader.loadClass("Test");
Method method = clazz.getDeclaredMethod("test", Integer.TYPE);
// Exception in thread "main" java.lang.reflect.MalformedParametersException: Invalid parameter name ""
// at java.lang.reflect.Executable.verifyParameters(Executable.java:386)
// at java.lang.reflect.Executable.privateGetParameters(Executable.java:416)
// at java.lang.reflect.Executable.getParameters(Executable.java:357)
// at Bug.main(Bug.java:37)
method.getParameters();
}
}
Best regards, Max

--
<http://www.oracle.com> Dalibor Topic | Principal Product Manager
Phone: [phone] <tel:[phone]> | Mobile: [phone]
<tel:[phone]>

ORACLE Deutschland B.V. & Co. KG | Kühnehöfe 5 | 22761 Hamburg

ORACLE Deutschland B.V. & Co. KG
Hauptverwaltung: Riesstr. 25, D-80992 München
Registergericht: Amtsgericht München, HRA 95603

Komplementärin: ORACLE Deutschland Verwaltung B.V.
Hertogswetering 163/167, 3543 AS Utrecht, Niederlande
Handelsregister der Handelskammer Midden-Niederlande, Nr. 30143697
Geschäftsführer: Alexander van der Ven, Jan Schultheiss, Val Maher

<http://www.oracle.com/commitment> Oracle is committed to developing
practices and products that help protect the environment

[Михаил Богданов]

#9045294

пятница, 18 ноября 2016 11:30 dalibor topic <***@oracle.com> писал(а):


Hi Mihail,

could you file an issue at bugs.java.com and let us know which incident
id you receive, please?

cheers,
dalibor topic

Post by Михаил Богданов
Hotspot  VM constructs nameless parameter with empty string name that cause Executable.verifyParameters to throw MalformedParametersException.
//Code to reproduce:import jdk.internal.org.objectweb.asm.ClassWriter;
import jdk.internal.org.objectweb.asm.MethodVisitor;
import jdk.internal.org.objectweb.asm.Opcodes;
import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLClassLoader;
public class Bug {
    public static void main(String[] args) throws ClassNotFoundException, NoSuchMethodException {
        ClassWriter writer = new ClassWriter(Opcodes.ASM5);
        writer.visit(Opcodes.V1_8, Opcodes.ACC_PUBLIC | Opcodes.ACC_INTERFACE | Opcodes.ACC_ABSTRACT, "Test", null, "java/lang/Object", null);
        MethodVisitor test = writer.visitMethod(Opcodes.ACC_PUBLIC | Opcodes.ACC_ABSTRACT, "test", "(I)V", null, null);
        test.visitParameter(null, 0);
        test.visitEnd();
        writer.visitEnd();
        final byte[] bytes = writer.toByteArray();
        URLClassLoader urlClassLoader = new URLClassLoader(new URL[0], ClassLoader.getSystemClassLoader()) {
            protected Class<?> findClass(String name) throws ClassNotFoundException {
                if (name.equals("Test")) {
                    return defineClass("Test", bytes, 0, bytes.length);
                }
                return super.findClass(name);
            }
        };
        Class<?> clazz = urlClassLoader.loadClass("Test");
        Method method = clazz.getDeclaredMethod("test", Integer.TYPE);
//        Exception in thread "main" java.lang.reflect.MalformedParametersException: Invalid parameter name ""
//        at java.lang.reflect.Executable.verifyParameters(Executable.java:386)
//        at java.lang.reflect.Executable.privateGetParameters(Executable.java:416)
//        at java.lang.reflect.Executable.getParameters(Executable.java:357)
//        at Bug.main(Bug.java:37)
        method.getParameters();
    }
}
Best regards,  Max

--
<http://www.oracle.com> Dalibor Topic | Principal Product Manager
Phone: [phone] <tel:[phone]> | Mobile: [phone]
<tel:[phone]>

ORACLE Deutschland B.V. & Co. KG | Kühnehöfe 5 | 22761 Hamburg

ORACLE Deutschland B.V. & Co. KG
Hauptverwaltung: Riesstr. 25, D-80992 München
Registergericht: Amtsgericht München, HRA 95603

Komplementärin: ORACLE Deutschland Verwaltung B.V.
Hertogswetering 163/167, 3543 AS Utrecht, Niederlande
Handelsregister der Handelskammer Midden-Niederlande, Nr. 30143697
Geschäftsführer: Alexander van der Ven, Jan Schultheiss, Val Maher

<http://www.oracle.com/commitment> Oracle is committed to developing
practices and products that help protect the environment