/// <summary>
/// Convert MarshalAsAttribute data into CustomAttributeData form. Returns null if the core assembly cannot be loaded or if the necessary
/// types aren't in the core assembly.
/// </summary>
public static CustomAttributeData?TryComputeMarshalAsCustomAttributeData(Func <MarshalAsAttribute> marshalAsAttributeComputer, MetadataLoadContext loader)
{
// Make sure all the necessary framework types exist in this MetadataLoadContext's core assembly. If one doesn't, skip.
CoreTypes ct = loader.GetAllFoundCoreTypes();
if (ct[CoreType.String] == null ||
ct[CoreType.Boolean] == null ||
ct[CoreType.UnmanagedType] == null ||
ct[CoreType.VarEnum] == null ||
ct[CoreType.Type] == null ||
ct[CoreType.Int16] == null ||
ct[CoreType.Int32] == null)
{
return(null);
}
ConstructorInfo?ci = loader.TryGetMarshalAsCtor();
if (ci == null)
{
return(null);
}
Func <CustomAttributeArguments> argumentsPromise =
() =>
{
// The expensive work goes in here. It will not execute unless someone invokes the Constructor/NamedArguments properties on
// the CustomAttributeData.
MarshalAsAttribute ma = marshalAsAttributeComputer();
Type attributeType = ci.DeclaringType !;
CustomAttributeTypedArgument[] cats = { new CustomAttributeTypedArgument(ct[CoreType.UnmanagedType] !, (int)(ma.Value)) };
/// <summary>
/// Convert MarshalAsAttribute data into CustomAttributeData form. Returns null if the core assembly cannot be loaded or if the necessary
/// types aren't in the core assembly.
/// </summary>
public static CustomAttributeData TryComputeMarshalAsCustomAttributeData(Func <MarshalAsAttribute> marshalAsAttributeComputer, MetadataLoadContext loader)
{
// Make sure all the necessary framework types exist in this MetadataLoadContext's core assembly. If one doesn't, skip.
CoreTypes ct = loader.GetAllFoundCoreTypes();
if (ct[CoreType.String] == null ||
ct[CoreType.Boolean] == null ||
ct[CoreType.UnmanagedType] == null ||
ct[CoreType.VarEnum] == null ||
ct[CoreType.Type] == null ||
ct[CoreType.Int16] == null ||
ct[CoreType.Int32] == null)
{
return(null);
}
ConstructorInfo ci = loader.TryGetMarshalAsCtor();
if (ci == null)
{
return(null);
}
Func <CustomAttributeArguments> argumentsPromise =
() =>
{
// The expensive work goes in here. It will not execute unless someone invokes the Constructor/NamedArguments properties on
// the CustomAttributeData.
MarshalAsAttribute ma = marshalAsAttributeComputer();
Type attributeType = ci.DeclaringType;
CustomAttributeTypedArgument[] cats = { new CustomAttributeTypedArgument(ct[CoreType.UnmanagedType], (int)(ma.Value)) };
List <CustomAttributeNamedArgument> cans = new List <CustomAttributeNamedArgument>();
cans.AddRange(new CustomAttributeNamedArgument[]
{
attributeType.ToCustomAttributeNamedArgument(nameof(MarshalAsAttribute.ArraySubType), ct[CoreType.UnmanagedType], (int)ma.ArraySubType),
attributeType.ToCustomAttributeNamedArgument(nameof(MarshalAsAttribute.IidParameterIndex), ct[CoreType.Int32], ma.IidParameterIndex),
attributeType.ToCustomAttributeNamedArgument(nameof(MarshalAsAttribute.SafeArraySubType), ct[CoreType.VarEnum], (int)ma.SafeArraySubType),
attributeType.ToCustomAttributeNamedArgument(nameof(MarshalAsAttribute.SizeConst), ct[CoreType.Int32], ma.SizeConst),
attributeType.ToCustomAttributeNamedArgument(nameof(MarshalAsAttribute.SizeParamIndex), ct[CoreType.Int16], ma.SizeParamIndex),
});
if (ma.SafeArrayUserDefinedSubType != null)
{
cans.Add(attributeType.ToCustomAttributeNamedArgument(nameof(MarshalAsAttribute.SafeArrayUserDefinedSubType), ct[CoreType.Type], ma.SafeArrayUserDefinedSubType));
}
if (ma.MarshalType != null)
{
cans.Add(attributeType.ToCustomAttributeNamedArgument(nameof(MarshalAsAttribute.MarshalType), ct[CoreType.String], ma.MarshalType));
}
if (ma.MarshalTypeRef != null)
{
cans.Add(attributeType.ToCustomAttributeNamedArgument(nameof(MarshalAsAttribute.MarshalTypeRef), ct[CoreType.Type], ma.MarshalTypeRef));
}
if (ma.MarshalCookie != null)
{
cans.Add(attributeType.ToCustomAttributeNamedArgument(nameof(MarshalAsAttribute.MarshalCookie), ct[CoreType.String], ma.MarshalCookie));
}
return(new CustomAttributeArguments(cats, cans));
};
return(new RoPseudoCustomAttributeData(ci, argumentsPromise));
}
