/// <summary>
/// Parses an SZArray attribute value.
/// </summary>
/// <param name="reader">The binary reader used to read from the attribute blob.</param>
/// <param name="sigType">Type of the SZArray.</param>
/// <returns>
/// An Array, which represents the SZArray definition.
/// </returns>
private static object ParseSZArrayArg(BinaryReader reader, SZArraySigType sigType)
{
// Return value
Array result;
// Determine the number of elements
int numElements = reader.ReadInt32();
if (-1 == numElements)
{
return(null);
}
// Retrieve the array element type
Type elementType = GetTypeFromSigType(sigType);
Debug.Assert(null != elementType, @"Failed to get System.Type for SigType.");
result = Array.CreateInstance(elementType, numElements);
for (int idx = 0; idx < numElements; idx++)
{
object item = ParseElem(reader, sigType.ElementType);
result.SetValue(item, idx);
}
return(result);
}
/// <summary>
/// Decodes the specified instruction.
/// </summary>
/// <param name="ctx">The context.</param>
/// <param name="decoder">The instruction decoder, which holds the code stream.</param>
public override void Decode(Context ctx, IInstructionDecoder decoder)
{
// Decode base classes first
base.Decode(ctx, decoder);
// Read the type specification
Token token = decoder.DecodeTokenType();
// FIXME: If ctx.Operands1 is an integral constant, we can infer the maximum size of the array
// and instantiate an ArrayTypeSpecification with max. sizes. This way we could eliminate bounds
// checks in an optimization stage later on, if we find that a value never exceeds the array
// bounds.
var resultType = new SZArraySigType(null, new ClassSigType(token));
ctx.Result = decoder.Compiler.CreateTemporary(resultType);
}
/// <summary>
/// Parses a fixed argument in an attribute blob definition.
/// </summary>
/// <param name="reader">The binary reader to read it From.</param>
/// <param name="sigType">The signature type of the value to read.</param>
/// <returns></returns>
private static object ParseFixedArg(BinaryReader reader, SigType sigType)
{
// Return value
object result = null;
// A vector?
SZArraySigType arraySigType = sigType as SZArraySigType;
if (arraySigType != null)
{
result = ParseSZArrayArg(reader, arraySigType);
}
else
{
result = ParseElem(reader, sigType);
}
return(result);
}