Condy that returns long or double generates bad bytecode
MethodWriter.visitLdcInsn should emit LDC2_W instead of LDC for condy of long/double.
import java.lang.invoke.MethodHandles;
import java.util.concurrent.atomic.AtomicReference;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.ConstantDynamic;
import org.objectweb.asm.Handle;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
public class Test implements Opcodes {
public static void main(String... args) throws Exception {
byte[] bytes = dumpBytes();
AtomicReference<Class<?>> ref = new AtomicReference<>();
new ClassLoader() {{
ref.set((Class<?>) defineClass("Target", bytes, 0, bytes.length));
}};
Class<?> c = ref.get();
Object o = c.getDeclaredConstructor().newInstance();
System.out.println(c.getDeclaredMethod("test").invoke(o));
}
public static long create(MethodHandles.Lookup lookup, String name, Class<?> owner) {
return 1;
}
public static byte[] dumpBytes() {
ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS);
cw.visit(V11, ACC_PUBLIC | ACC_SUPER, "Target", null, "java/lang/Object", null);
MethodVisitor mv;
mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
mv.visitCode();
mv.visitVarInsn(ALOAD, 0);
mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V", false);
mv.visitInsn(RETURN);
mv.visitMaxs(1, 1);
mv.visitEnd();
mv = cw.visitMethod(ACC_PUBLIC, "test", "()J", null, null);
mv.visitCode();
mv.visitLdcInsn(new ConstantDynamic("test", "J", new Handle(H_INVOKESTATIC, "Test", "create", "(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/Class;)J", false)));
mv.visitInsn(LRETURN);
mv.visitMaxs(0, 0);
mv.visitEnd();
cw.visitEnd();
return cw.toByteArray();
}
}