protected static void GenerateCodeForArgument(ILGenerator gen, CodeFlow cf, SpelNode argument, TypeDescriptor paramDesc)
{
cf.EnterCompilationScope();
argument.GenerateCode(gen, cf);
var lastDesc = cf.LastDescriptor();
if (lastDesc == null)
{
throw new InvalidOperationException("No last descriptor");
}
var valueTypeOnStack = CodeFlow.IsValueType(lastDesc);
// Check if need to box it for the method reference?
if (valueTypeOnStack && paramDesc.IsReferenceType)
{
CodeFlow.InsertBoxIfNecessary(gen, lastDesc);
}
else if (paramDesc.IsValueType && !paramDesc.IsBoxed && !valueTypeOnStack)
{
gen.Emit(OpCodes.Unbox_Any, paramDesc.Value);
}
else
{
// This would be unnecessary in the case of subtyping (e.g. method takes Number but Integer passed in)
CodeFlow.InsertCastClass(gen, paramDesc);
}
cf.ExitCompilationScope();
}
private void GenerateInstanceMethodCode(ILGenerator gen, CodeFlow cf, MethodInfo targetMethod, Type targetType)
{
var stackDescriptor = cf.LastDescriptor();
if (stackDescriptor == null)
{
// Nothing on the stack but something is needed
CodeFlow.LoadTarget(gen);
stackDescriptor = TypeDescriptor.OBJECT;
}
Label?skipIfNullTarget = null;
if (_nullSafe)
{
skipIfNullTarget = GenerateNullCheckCode(gen);
}
if (targetType.IsValueType)
{
if (stackDescriptor.IsBoxed || stackDescriptor.IsReferenceType)
{
gen.Emit(OpCodes.Unbox_Any, targetType);
}
var local = gen.DeclareLocal(targetType);
gen.Emit(OpCodes.Stloc, local);
gen.Emit(OpCodes.Ldloca, local);
}
else
{
if (stackDescriptor.Value != targetType)
{
CodeFlow.InsertCastClass(gen, new TypeDescriptor(targetType));
}
}
GenerateCodeForArguments(gen, cf, targetMethod, _children);
if (targetType.IsValueType)
{
gen.Emit(OpCodes.Call, targetMethod);
}
else
{
gen.Emit(OpCodes.Callvirt, targetMethod);
}
if (_originalPrimitiveExitTypeDescriptor != null)
{
// The output of the accessor will be a primitive but from the block above it might be null,
// so to have a 'common stack' element at skipIfNull target we need to box the primitive
CodeFlow.InsertBoxIfNecessary(gen, _originalPrimitiveExitTypeDescriptor);
}
if (skipIfNullTarget.HasValue)
{
gen.MarkLabel(skipIfNullTarget.Value);
}
}
public override void GenerateCode(ILGenerator gen, CodeFlow cf)
{
if (_name.Equals(ROOT))
{
CodeFlow.LoadTarget(gen);
}
else
{
gen.Emit(OpCodes.Ldarg_2);
gen.Emit(OpCodes.Ldstr, _name);
gen.Emit(OpCodes.Callvirt, GetLookUpVariableMethod());
}
CodeFlow.InsertCastClass(gen, _exitTypeDescriptor);
cf.PushDescriptor(_exitTypeDescriptor);
}
private Label GenerateNullCheckCode(ILGenerator gen)
{
var skipIfNullTarget = gen.DefineLabel();
var continueTarget = gen.DefineLabel();
gen.Emit(OpCodes.Dup);
gen.Emit(OpCodes.Ldnull);
gen.Emit(OpCodes.Cgt_Un);
gen.Emit(OpCodes.Brtrue, continueTarget);
// cast null on stack to result type
CodeFlow.InsertCastClass(gen, _exitTypeDescriptor);
gen.Emit(OpCodes.Br, skipIfNullTarget);
gen.MarkLabel(continueTarget);
return(skipIfNullTarget);
}
