Java Code Examples for org.objectweb.asm.commons.GeneratorAdapter#unbox()

/**
 * Given an array with values at the top of the stack, the values are unboxed and stored
 * on the given variables. The array is popped from the stack.
 */
static void restoreVariables(
        @NonNull GeneratorAdapter mv,
        @NonNull List<LocalVariable> variables) {
    for (int i = 0; i < variables.size(); i++) {
        LocalVariable variable = variables.get(i);
        // Duplicates the array on the stack;
        mv.dup();
        // Sets up the index
        mv.push(i);
        // Gets the Object value
        mv.arrayLoad(Type.getType(Object.class));
        // Unboxes to the type of the local variable
        mv.unbox(variable.type);
        // Restores the local variable
        mv.visitVarInsn(variable.type.getOpcode(Opcodes.ISTORE), variable.var);
    }
    // Pops the array from the stack.
    mv.pop();
}
 

@Override
public Type load(Context ctx) {
	GeneratorAdapter g = ctx.getGeneratorAdapter();
	Type accumulatorType = accumulator.load(ctx);
	Type valueType = value.load(ctx);
	String methodName;
	Type methodParameterType;
	if (valueType == LONG_TYPE || valueType.getClassName().equals(Long.class.getName())) {
		methodName = "addLong";
		methodParameterType = LONG_TYPE;
	} else if (valueType == INT_TYPE || valueType.getClassName().equals(Integer.class.getName())) {
		methodName = "addInt";
		methodParameterType = INT_TYPE;
	} else {
		methodName = "addObject";
		methodParameterType = getType(Object.class);
	}

	if (isWrapperType(valueType)) {
		g.unbox(methodParameterType);
	}

	ctx.invoke(accumulatorType, methodName, methodParameterType);

	return VOID_TYPE;
}
 

/**
 * Generates unboxing bytecode for the passed type. An {@link Object} is expected to be on the
 * stack when these bytecodes are inserted.
 *
 * ASM takes a short cut when dealing with short/byte types and convert them into int rather
 * than short/byte types. This is not an issue on the jvm nor Android's ART but it is an issue
 * on Dalvik.
 *
 * @param mv the {@link GeneratorAdapter} generating a method implementation.
 * @param type the expected un-boxed type.
 */
public static void unbox(GeneratorAdapter mv, Type type) {
    if (type.equals(Type.SHORT_TYPE)) {
        mv.checkCast(NUMBER_TYPE);
        mv.invokeVirtual(NUMBER_TYPE, SHORT_VALUE);
    } else if (type.equals(Type.BYTE_TYPE)) {
        mv.checkCast(NUMBER_TYPE);
        mv.invokeVirtual(NUMBER_TYPE, BYTE_VALUE);
    } else {
        mv.unbox(type);
    }
}
 

/**
 * Generates unboxing bytecode for the passed type. An {@link Object} is expected to be on the
 * stack when these bytecodes are inserted.
 *
 * ASM takes a short cut when dealing with short/byte types and convert them into int rather
 * than short/byte types. This is not an issue on the jvm nor Android's ART but it is an issue
 * on Dalvik.
 *
 * @param mv the {@link GeneratorAdapter} generating a method implementation.
 * @param type the expected un-boxed type.
 */
public static void unbox(GeneratorAdapter mv, Type type) {
    if (type.equals(Type.SHORT_TYPE)) {
        mv.checkCast(NUMBER_TYPE);
        mv.invokeVirtual(NUMBER_TYPE, SHORT_VALUE);
    } else if (type.equals(Type.BYTE_TYPE)) {
        mv.checkCast(NUMBER_TYPE);
        mv.invokeVirtual(NUMBER_TYPE, BYTE_VALUE);
    } else {
        mv.unbox(type);
    }
}
 

/**
 * Generates unboxing bytecode for the passed type. An {@link Object} is expected to be on the
 * stack when these bytecodes are inserted.
 *
 * ASM takes a short cut when dealing with short/byte types and convert them into int rather
 * than short/byte types. This is not an issue on the jvm nor Android's ART but it is an issue
 * on Dalvik.
 *
 * @param mv the {@link GeneratorAdapter} generating a method implementation.
 * @param type the expected un-boxed type.
 */
public static void unbox(GeneratorAdapter mv, Type type) {
    if (type.equals(Type.SHORT_TYPE)) {
        mv.checkCast(NUMBER_TYPE);
        mv.invokeVirtual(NUMBER_TYPE, SHORT_VALUE);
    } else if (type.equals(Type.BYTE_TYPE)) {
        mv.checkCast(NUMBER_TYPE);
        mv.invokeVirtual(NUMBER_TYPE, BYTE_VALUE);
    } else {
        mv.unbox(type);
    }
}
 

@Override
public Type load(Context ctx) {
	GeneratorAdapter g = ctx.getGeneratorAdapter();
	Type leftType = left.load(ctx);
	if (isWrapperType(leftType)) {
		leftType = unwrap(leftType);
		g.unbox(leftType);
	}
	Type rightType = right.load(ctx);
	if (isWrapperType(rightType)) {
		rightType = unwrap(rightType);
		g.unbox(rightType);
	}
	if (op != SHL && op != SHR && op != USHR) {
		Type resultType = getType(unifyArithmeticTypes(ctx.toJavaType(leftType), ctx.toJavaType(rightType)));
		if (leftType != resultType) {
			int rightLocal = g.newLocal(rightType);
			g.storeLocal(rightLocal);
			g.cast(leftType, resultType);
			g.loadLocal(rightLocal);
		}
		if (rightType != resultType) {
			g.cast(rightType, resultType);
		}
		g.visitInsn(resultType.getOpcode(op.opCode));
		return resultType;
	} else {
		if (rightType != Type.getType(int.class)) {
			g.cast(rightType, Type.getType(int.class));
		}
		g.visitInsn(leftType.getOpcode(op.opCode));
		return leftType;
	}
}
 

/***
 * Inserts a trampoline to this class so that the updated methods can make calls to
 * constructors.
 * <p>
 * <p/>
 * Pseudo code for this trampoline:
 * <code>
 * ClassName(Object[] args, Marker unused) {
 * String name = (String) args[0];
 * if (name.equals(
 * "java/lang/ClassName.(Ljava/lang/String;Ljava/lang/Object;)Ljava/lang/Object;")) {
 * this((String)arg[1], arg[2]);
 * return
 * }
 * if (name.equals("SuperClassName.(Ljava/lang/String;I)V")) {
 * super((String)arg[1], (int)arg[2]);
 * return;
 * }
 * ...
 * StringBuilder $local1 = new StringBuilder();
 * $local1.append("Method not found ");
 * $local1.append(name);
 * $local1.append(" in " $classType $super implementation");
 * throw new $package/InstantReloadException($local1.toString());
 * }
 * </code>
 */
private void createDispatchingThis() {
    // Gather all methods from itself and its superclasses to generate a giant constructor
    // implementation.
    // This will work fine as long as we don't support adding constructors to classes.
    final Map<String, MethodNode> uniqueMethods = new HashMap<String, MethodNode>();

    addAllNewConstructors(uniqueMethods, classNode, true /*keepPrivateConstructors*/);
    for (ClassNode parentNode : parentNodes) {
        addAllNewConstructors(uniqueMethods, parentNode, false /*keepPrivateConstructors*/);
    }

    int access = Opcodes.ACC_PUBLIC | Opcodes.ACC_SYNTHETIC;

    Method m = new Method(AsmUtils.CONSTRUCTOR,
            ConstructorArgsRedirection.DISPATCHING_THIS_SIGNATURE);
    MethodVisitor visitor = super.visitMethod(0, m.getName(), m.getDescriptor(), null, null);
    final GeneratorAdapter mv = new GeneratorAdapter(access, m, visitor);

    mv.visitCode();
    // Mark this code as redirection code
    Label label = new Label();
    mv.visitLineNumber(0, label);

    // Get and store the constructor canonical name.
    mv.visitVarInsn(Opcodes.ALOAD, 1);
    mv.push(0);
    mv.visitInsn(Opcodes.AALOAD);
    mv.unbox(Type.getType("Ljava/lang/String;"));
    final int constructorCanonicalName = mv.newLocal(Type.getType("Ljava/lang/String;"));
    mv.storeLocal(constructorCanonicalName);

    new StringSwitch() {

        @Override
        void visitString() {
            mv.loadLocal(constructorCanonicalName);
        }

        @Override
        void visitCase(String canonicalName) {
            MethodNode methodNode = uniqueMethods.get(canonicalName);
            String owner = canonicalName.split("\\.")[0];

            // Parse method arguments and
            mv.visitVarInsn(Opcodes.ALOAD, 0);
            Type[] args = Type.getArgumentTypes(methodNode.desc);
            int argc = 0;
            for (Type t : args) {
                mv.visitVarInsn(Opcodes.ALOAD, 1);
                mv.push(argc + 1);
                mv.visitInsn(Opcodes.AALOAD);
                ByteCodeUtils.unbox(mv, t);
                argc++;
            }

            mv.visitMethodInsn(Opcodes.INVOKESPECIAL, owner, AsmUtils.CONSTRUCTOR,
                    methodNode.desc, false);

            mv.visitInsn(Opcodes.RETURN);
        }

        @Override
        void visitDefault() {
            writeMissingMessageWithHash(mv, visitedClassName);
        }
    }.visit(mv, uniqueMethods.keySet());

    mv.visitMaxs(1, 3);
    mv.visitEnd();
}
 

private static void defineMethod(ClassWriter cw, java.lang.reflect.Method method, Type proxyType)
{
    Type methodType = Type.getType(method);
    
    ArrayList<Type> exceptionsToCatch = new ArrayList<Type>();
    for (Class<?> exception : method.getExceptionTypes())
    {
        if (!RuntimeException.class.isAssignableFrom(exception))
        {
            exceptionsToCatch.add(Type.getType(exception));
        }
    }
    
    // push the method definition
    int modifiers = (Opcodes.ACC_PUBLIC | Opcodes.ACC_PROTECTED) & method.getModifiers();
    Method asmMethod = Method.getMethod(method);
    GeneratorAdapter mg = new GeneratorAdapter(modifiers,
            asmMethod,
            null,
            getTypes(method.getExceptionTypes()),
            cw);

    // copy annotations
    for (Annotation annotation : method.getDeclaredAnnotations())
    {
        mg.visitAnnotation(Type.getDescriptor(annotation.annotationType()), true).visitEnd();
    }

    mg.visitCode();

    Label tryBlockStart = mg.mark();

    mg.loadThis();
    mg.getField(proxyType, FIELDNAME_INVOCATION_HANDLER, TYPE_DELTA_SPIKE_PROXY_INVOCATION_HANDLER);
    mg.loadThis();
    loadCurrentMethod(mg, method, methodType);
    loadArguments(mg, method, methodType);
    
    mg.invokeVirtual(TYPE_DELTA_SPIKE_PROXY_INVOCATION_HANDLER,
            Method.getMethod("Object invoke(Object, java.lang.reflect.Method, Object[])"));

    // cast the result
    mg.unbox(methodType.getReturnType());

    // build try catch
    Label tryBlockEnd = mg.mark();
    
    // push return
    mg.returnValue();

    // catch runtime exceptions and rethrow it
    Label rethrow = mg.mark();
    mg.visitVarInsn(Opcodes.ASTORE, 1);
    mg.visitVarInsn(Opcodes.ALOAD, 1);
    mg.throwException();
    mg.visitTryCatchBlock(tryBlockStart, tryBlockEnd, rethrow, Type.getInternalName(RuntimeException.class));

    // catch checked exceptions and rethrow it
    boolean throwableCatched = false;
    if (!exceptionsToCatch.isEmpty())
    {
        rethrow = mg.mark();
        mg.visitVarInsn(Opcodes.ASTORE, 1);
        mg.visitVarInsn(Opcodes.ALOAD, 1);
        mg.throwException();

        // catch declared exceptions and rethrow it...
        for (Type exceptionType : exceptionsToCatch)
        {
            if (exceptionType.getClassName().equals(Throwable.class.getName()))
            {
                throwableCatched = true;
            }
            mg.visitTryCatchBlock(tryBlockStart, tryBlockEnd, rethrow, exceptionType.getInternalName());
        }
    }

    // if throwable isn't alreached cachted, catch it and wrap it with an UndeclaredThrowableException and throw it
    if (!throwableCatched)
    {
        Type uteType = Type.getType(UndeclaredThrowableException.class);
        Label wrapAndRethrow = mg.mark();

        mg.visitVarInsn(Opcodes.ASTORE, 1);
        mg.newInstance(uteType);
        mg.dup();
        mg.visitVarInsn(Opcodes.ALOAD, 1);
        mg.invokeConstructor(uteType,
                Method.getMethod("void <init>(java.lang.Throwable)"));
        mg.throwException();

        mg.visitTryCatchBlock(tryBlockStart, tryBlockEnd, wrapAndRethrow, Type.getInternalName(Throwable.class));
    }

    // finish the method
    mg.endMethod();
    mg.visitMaxs(12, 12);
    mg.visitEnd();
}