private void DefineParameter(MethodBuilder methodBuilder, ConstructorBuilder constructorBuilder, Cci.IParameterDefinition paramDef)
{
// No explicit param row is needed if param has no flags (other than optionally IN),
// no name and no references to the param row, such as CustomAttribute, Constant, or FieldMarshall
var attributes = paramDef.GetAttributes(_context);
var defaultValue = paramDef.GetDefaultValue(_context);
if (defaultValue != null ||
paramDef.IsOptional ||
paramDef.IsOut ||
paramDef.IsMarshalledExplicitly ||
attributes.Any() ||
paramDef.Name.Length > 0)
{
int index = paramDef is Cci.ReturnValueParameter ? 0 : paramDef.Index + 1;
ParameterAttributes attrs = (ParameterAttributes)Cci.MetadataWriter.GetParameterFlags(paramDef);
ParameterBuilder paramBuilder = (methodBuilder != null) ?
methodBuilder.DefineParameter(index, attrs, paramDef.Name) :
constructorBuilder.DefineParameter(index, attrs, paramDef.Name);
if (defaultValue != null)
{
object rawValue = defaultValue.Value;
if (rawValue == null)
{
var paramTypeRef = paramDef.GetType(_context);
if (paramTypeRef.IsValueType)
{
SetParameterDefaultStructValue(paramBuilder);
}
else
{
paramBuilder.SetConstant(null);
}
}
else
{
// TODO (tomat): Ref.Emit has too strict checks on the constant type. While it is ok to emit value,
// e.g. of type Int16 for parameter of type Int32 to metadata, Ref.Emit checks if these types are Type.IsAssignableFrom.
// To make this work we need to convert.
//
// We also need to support Nullable<T>.
if (rawValue.GetType().IsPrimitive)
{
// parameter type has already been resolved once when defining the method, so just retrive it:
Type paramType = ResolveType(paramDef.GetType(_context));
if (paramType.IsGenericType && paramType.GetGenericTypeDefinition() == typeof(Nullable<>))
{
paramType = paramType.GetGenericArguments()[0];
}
if (paramType.IsEnum)
{
// If emitting the enum, it isn't "created" as this stage so Enum.GetUnderlyingType() will throw
// Otherwise, if the enum is already defined, we should use Enum.GetUnderlyingType() to get the correct type
paramType = paramType is TypeBuilder ? paramType.UnderlyingSystemType : Enum.GetUnderlyingType(paramType);
}
rawValue = Convert.ChangeType(rawValue, paramType, System.Globalization.CultureInfo.InvariantCulture);
}
paramBuilder.SetConstant(rawValue);
}
}
if (paramDef.IsMarshalledExplicitly)
{
// FieldMarshal
var marshallingInformation = paramDef.MarshallingInformation;
if (marshallingInformation != null)
{
paramBuilder.SetCustomAttribute(GetMarshalAsAttribute(marshallingInformation));
}
else
{
Debug.Assert(!paramDef.MarshallingDescriptor.IsDefaultOrEmpty);
// TODO:
throw new NotImplementedException();
}
}
EmitCustomAttributes(paramBuilder, attributes);
}
}