/// <summary>
/// Reads a single argument from the provided input stream.
/// </summary>
/// <param name="parentModule">The module the signature resides in.</param>
/// <param name="argumentType">The type of the argument to read.</param>
/// <param name="reader">The input stream.</param>
/// <returns>The argument.</returns>
public static CustomAttributeArgument FromReader(ModuleDefinition parentModule, TypeSignature argumentType,
IBinaryStreamReader reader)
{
var elementReader = new CustomAttributeArgumentReader(parentModule, reader);
elementReader.ReadValue(argumentType);
return(new CustomAttributeArgument(argumentType, elementReader.Elements)
{
IsNullArray = elementReader.IsNullArray
});
}
public void ReadValue(TypeSignature valueType)
{
if (valueType.IsTypeOf("System", "Type"))
{
Elements.Add(TypeNameParser.Parse(_parentModule, _reader.ReadSerString()));
return;
}
switch (valueType.ElementType)
{
case ElementType.Boolean:
Elements.Add(_reader.ReadByte() == 1);
break;
case ElementType.Char:
Elements.Add((char)_reader.ReadUInt16());
break;
case ElementType.R4:
Elements.Add(_reader.ReadSingle());
break;
case ElementType.R8:
Elements.Add(_reader.ReadDouble());
break;
case ElementType.I1:
Elements.Add(_reader.ReadSByte());
break;
case ElementType.I2:
Elements.Add(_reader.ReadInt16());
break;
case ElementType.I4:
Elements.Add(_reader.ReadInt32());
break;
case ElementType.I8:
Elements.Add(_reader.ReadInt64());
break;
case ElementType.U1:
Elements.Add(_reader.ReadByte());
break;
case ElementType.U2:
Elements.Add(_reader.ReadUInt16());
break;
case ElementType.U4:
Elements.Add(_reader.ReadUInt32());
break;
case ElementType.U8:
Elements.Add(_reader.ReadUInt64());
break;
case ElementType.String:
Elements.Add(_reader.ReadSerString());
break;
case ElementType.Object:
var reader = new CustomAttributeArgumentReader(_parentModule, _reader);
var type = TypeSignature.ReadFieldOrPropType(_parentModule, _reader);
reader.ReadValue(type);
Elements.Add(new BoxedArgument(type, type.ElementType == ElementType.SzArray
? reader.Elements.ToArray()
: reader.Elements[0]));
break;
case ElementType.SzArray:
var arrayElementType = ((SzArrayTypeSignature)valueType).BaseType;
uint elementCount = _reader.CanRead(sizeof(uint)) ? _reader.ReadUInt32() : uint.MaxValue;
IsNullArray = elementCount == uint.MaxValue;
if (!IsNullArray)
{
for (uint i = 0; i < elementCount; i++)
{
ReadValue(arrayElementType);
}
}
break;
case ElementType.Class:
case ElementType.Enum:
case ElementType.ValueType:
// Value is an enum, resolve it and get underlying type.
// If that fails, most enums are int32s, assume that is the case in an attempt to recover.
var enumTypeDef = _parentModule.MetadataResolver.ResolveType(valueType);
TypeSignature underlyingType;
if (enumTypeDef is null)
{
underlyingType = _parentModule.CorLibTypeFactory.Int32;
}
else if (enumTypeDef.IsEnum)
{
underlyingType = enumTypeDef.GetEnumUnderlyingType() ?? _parentModule.CorLibTypeFactory.Int32;
}
else
{
throw new NotSupportedException($"Type {valueType} is not an enum.");
}
ReadValue(underlyingType);
break;
default:
throw new NotSupportedException($"Unsupported element type {valueType.ElementType}.");
}
}