Java InstructionAdapter.checkcast方法代码示例

import jdk.internal.org.objectweb.asm.commons.InstructionAdapter; //导入方法依赖的package包/类
private void generateClassInit() {
    final InstructionAdapter mv = new InstructionAdapter(cw.visitMethod(ACC_STATIC, CLASS_INIT,
            VOID_METHOD_DESCRIPTOR, null, null));

    // Assign "global = Context.getGlobal()"
    GET_NON_NULL_GLOBAL.invoke(mv);
    mv.putstatic(generatedClassName, GLOBAL_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR);

    GET_CLASS_OVERRIDES.invoke(mv);
    if(samName != null) {
        // If the class is a SAM, allow having ScriptFunction passed as class overrides
        mv.dup();
        mv.instanceOf(SCRIPT_FUNCTION_TYPE);
        mv.dup();
        mv.putstatic(generatedClassName, IS_FUNCTION_FIELD_NAME, BOOLEAN_TYPE_DESCRIPTOR);
        final Label notFunction = new Label();
        mv.ifeq(notFunction);
        mv.dup();
        mv.checkcast(SCRIPT_FUNCTION_TYPE);
        emitInitCallThis(mv);
        mv.visitLabel(notFunction);
    }
    mv.putstatic(generatedClassName, DELEGATE_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR);

    endInitMethod(mv);
}
 

import jdk.internal.org.objectweb.asm.commons.InstructionAdapter; //导入方法依赖的package包/类
private void generateClassInit() {
    final InstructionAdapter mv = new InstructionAdapter(cw.visitMethod(ACC_STATIC, CLASS_INIT,
            VOID_METHOD_DESCRIPTOR, null, null));

    // Assign "global = Context.getGlobal()"
    GET_NON_NULL_GLOBAL.invoke(mv);
    mv.putstatic(generatedClassName, GLOBAL_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR);

    GET_CLASS_OVERRIDES.invoke(mv);
    if(samName != null) {
        // If the class is a SAM, allow having ScriptFunction passed as class overrides
        mv.dup();
        mv.instanceOf(SCRIPT_FUNCTION_TYPE);
                mv.dup();
        mv.putstatic(generatedClassName, IS_FUNCTION_FIELD_NAME, BOOLEAN_TYPE_DESCRIPTOR);
        final Label notFunction = new Label();
        mv.ifeq(notFunction);
        mv.dup();
        mv.checkcast(SCRIPT_FUNCTION_TYPE);
        emitInitCallThis(mv);
        mv.visitLabel(notFunction);
    }
    mv.putstatic(generatedClassName, DELEGATE_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR);

    endInitMethod(mv);
}
 

import jdk.internal.org.objectweb.asm.commons.InstructionAdapter; //导入方法依赖的package包/类
private void generateFinalizerDelegate(final String finalizerDelegateName) {
    // Generate a delegate that will be invoked from the no-permission trampoline. Note it can be private, as we'll
    // refer to it with a MethodHandle constant pool entry in the overridden finalize() method (see
    // generateFinalizerOverride()).
    final InstructionAdapter mv = new InstructionAdapter(cw.visitMethod(ACC_PRIVATE | ACC_STATIC,
            finalizerDelegateName, Type.getMethodDescriptor(Type.VOID_TYPE, OBJECT_TYPE), null, null));

    // Simply invoke super.finalize()
    mv.visitVarInsn(ALOAD, 0);
    mv.checkcast(Type.getType(generatedClassName));
    mv.invokespecial(superClassName, "finalize", Type.getMethodDescriptor(Type.VOID_TYPE), false);

    mv.visitInsn(RETURN);
    endMethod(mv);
}
 

import jdk.internal.org.objectweb.asm.commons.InstructionAdapter; //导入方法依赖的package包/类
private void generateFinalizerDelegate() {
    // Generate a delegate that will be invoked from the no-permission trampoline. Note it can be private, as we'll
    // refer to it with a MethodHandle constant pool entry in the overridden finalize() method (see
    // generateFinalizerOverride()).
    final InstructionAdapter mv = new InstructionAdapter(cw.visitMethod(ACC_PRIVATE | ACC_STATIC,
            FINALIZER_DELEGATE_NAME, FINALIZER_DELEGATE_METHOD_DESCRIPTOR, null, null));

    // Simply invoke super.finalize()
    mv.visitVarInsn(ALOAD, 0);
    mv.checkcast(Type.getType(generatedClassName));
    mv.invokespecial(superClassName, "finalize", VOID_METHOD_DESCRIPTOR, false);

    mv.visitInsn(RETURN);
    endMethod(mv);
}
 

import jdk.internal.org.objectweb.asm.commons.InstructionAdapter; //导入方法依赖的package包/类
private void generateOverridingConstructorWithObjectParam(final InstructionAdapter mv, final String ctorDescriptor) {
    mv.visitCode();
    final int extraArgOffset = emitSuperConstructorCall(mv, ctorDescriptor);

    // Check for ScriptObjectMirror
    mv.visitVarInsn(ALOAD, extraArgOffset);
    mv.instanceOf(SCRIPT_OBJECT_MIRROR_TYPE);
    final Label notMirror = new Label();
    mv.ifeq(notMirror);

    mv.visitVarInsn(ALOAD, 0);
    mv.visitVarInsn(ALOAD, extraArgOffset);
    mv.iconst(0);
    UNWRAP_MIRROR.invoke(mv);
    mv.putfield(generatedClassName, DELEGATE_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR);

    mv.visitVarInsn(ALOAD, 0);
    mv.visitVarInsn(ALOAD, extraArgOffset);
    mv.iconst(1);
    UNWRAP_MIRROR.invoke(mv);
    mv.putfield(generatedClassName, GLOBAL_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR);

    final Label done = new Label();

    if (samName != null) {
        mv.visitVarInsn(ALOAD, 0);
        mv.getfield(generatedClassName, DELEGATE_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR);
        mv.instanceOf(SCRIPT_FUNCTION_TYPE);
        mv.ifeq(done);

        // Assign "isFunction = true"
        mv.visitVarInsn(ALOAD, 0);
        mv.iconst(1);
        mv.putfield(generatedClassName, IS_FUNCTION_FIELD_NAME, BOOLEAN_TYPE_DESCRIPTOR);

        mv.visitVarInsn(ALOAD, 0);
        mv.dup();
        mv.getfield(generatedClassName, DELEGATE_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR);
        mv.checkcast(SCRIPT_FUNCTION_TYPE);
        emitInitCallThis(mv);
        mv.goTo(done);
    }

    mv.visitLabel(notMirror);

    // Throw error if not a ScriptObject
    mv.visitVarInsn(ALOAD, extraArgOffset);
    NOT_AN_OBJECT.invoke(mv);

    mv.visitLabel(done);
    endInitMethod(mv);
}