public static void Indirection(JavaCode code, Code cilOp)
{
var(name, opcodeType) = IndirectOpCodeToNameAndType(cilOp);
bool isRef = opcodeType.Equals(JavaType.ObjectType);
bool isLoad;
if (cilOp >= Code.Ldind_I1 && cilOp <= Code.Ldind_Ref)
{
isLoad = true;
}
else
{
isLoad = false;
var valueType = code.StackMap.PopStack(CilMain.Where);
if (valueType.IsReference != isRef)
{
throw new InvalidProgramException();
}
}
var stackTop = (CilType)code.StackMap.PopStack(CilMain.Where);
if (stackTop.IsGenericParameter)
{
if (isLoad)
{
var resultType = GenericUtil.CastMaybeGeneric(stackTop, false, code);
if (resultType == stackTop && (!stackTop.Equals(JavaType.ObjectType)))
{
code.NewInstruction(0xC0 /* checkcast */, stackTop.AsWritableClass, null);
resultType = stackTop;
}
code.StackMap.PushStack(resultType);
}
else
{
code.NewInstruction(0x5F /* swap */, null, null);
GenericUtil.ValueCopy(stackTop, code);
}
return;
}
//
// non-generic object reference
//
var boxedType = stackTop as BoxedType;
if (boxedType == null || boxedType.IsBoxedReference != isRef)
{
if (CodeSpan.LoadStore(isLoad, stackTop, opcodeType, null, code))
{
return;
}
if (object.ReferenceEquals(stackTop, CodeArrays.GenericArrayType))
{
// a byref parameter T[] gets translated to java.lang.Object,
// so we have to explicitly cast it to system.Reference
boxedType = new BoxedType(stackTop, false);
code.NewInstruction(0x5F /* swap */, null, null);
code.NewInstruction(0xC0 /* checkcast */,
boxedType.AsWritableClass, null);
code.NewInstruction(0x5F /* swap */, null, null);
}
else
{
throw new ArgumentException($"incompatible type '{stackTop}'");
}
}
var unboxedType = boxedType.UnboxedType;
var unboxedTypeCode = unboxedType.IsReference ? 0 : unboxedType.PrimitiveType;
JavaMethodRef method;
if (CompareIndirectTypes(unboxedTypeCode, opcodeType.PrimitiveType))
{
// indirect access to a primitive or reference type, with a
// reference type that represents the boxed form of the same type.
if (isLoad)
{
boxedType.GetValue(code);
if (unboxedType.IsReference)
{
// if we know the type of indirected value, cast to it
if (!unboxedType.Equals(JavaType.ObjectType))
{
code.NewInstruction(0xC0 /* checkcast */,
unboxedType.AsWritableClass, null);
}
}
else
{
unboxedType = CilType.From(opcodeType);
}
code.StackMap.PushStack(unboxedType);
}
else
{
// if we are storing a real array into a boxed reference of
// e.g., system.Array, then we have to create an array proxy
CodeArrays.MaybeGetProxy(CodeArrays.GenericArrayType, unboxedType, code);
boxedType.SetValueOV(code);
}
return;
}
// indirect access to a primitive value from a reference type that
// represents some other a primitive value; for example ldind.r4
// from a system.Int32. we call the "CodeNumber.Indirection methods"
// helpers, defined in all baselib primitives, to assist.
if (opcodeType.IsIntLike)
{
opcodeType = JavaType.IntegerType;
}
if (isLoad)
{
method = new JavaMethodRef("Get_" + name, opcodeType);
code.StackMap.PushStack(CilType.From(opcodeType));
}
else
{
method = new JavaMethodRef("Set_" + name, JavaType.VoidType, opcodeType);
}
code.NewInstruction(0xB6 /* invokevirtual */, boxedType, method);
}
