public InstructionInfo[] BuildInstructionInfo(Type type)
{
var instructions = new List<InstructionInfo>();
foreach (var property in type.GetProperties())
{
foreach (var att in property.GetCustomAttributes(typeof(InstructionAttribute), false).Cast<InstructionAttribute>())
{
Object instructionObject = BuildInstructionObject(type);
var info = new InstructionInfo() { Mnemonic = att.Mnemonic, Opcode = att.Opcode };
if (att.Cycles == 0)
info.Cycles = null;
else
info.Cycles = att.Cycles;
info.Body = (Expression)property.GetValue(instructionObject, null);
if (info.Body == null)
throw new NullExpressionException(String.Format("The instruction {0} on {1} was null.", property.Name, type));
info.ParameterMode = att.ParameterMode;
info.InstructionObject = instructionObject;
info.Prefix = att.Prefix;
instructions.Add(info);
}
}
return instructions.ToArray();
}
public Expression BuildExpression(InstructionInfo info)
{
if (info.Body == null)
throw new NullExpressionException();
var expressions = new List<Expression>();
switch (info.ParameterMode)
{
case InstructionParameterMode.None:
break;
case InstructionParameterMode.Byte:
expressions.Add(Expression.Assign(_programControlExpressionLibrary.ParameterByte1, _programControlExpressionLibrary.ReadAndIncrementProgramCounter));
break;
case InstructionParameterMode.Index:
// index - (index & 0x80) << 1 - Handles negative indexes.
expressions.Add(Expression.Assign(_programControlExpressionLibrary.ParameterByte2, _programControlExpressionLibrary.ReadAndIncrementProgramCounter));
expressions.Add(Expression.Assign(_programControlExpressionLibrary.ParameterByte1,
Expression.Subtract(
_programControlExpressionLibrary.ParameterByte2,
Expression.LeftShift(
Expression.And(_programControlExpressionLibrary.ParameterByte2, Expression.Constant(0x80)), Expression.Constant(0x01)
)
)
)
);
break;
case InstructionParameterMode.IndexAndByte:
// index - (index & 0x80) << 1 - Handles negative indexes.
expressions.Add(Expression.Assign(_programControlExpressionLibrary.ParameterByte2, _programControlExpressionLibrary.ReadAndIncrementProgramCounter));
expressions.Add(Expression.Assign(_programControlExpressionLibrary.ParameterByte1,
Expression.Subtract(
_programControlExpressionLibrary.ParameterByte2,
Expression.LeftShift(
Expression.And(_programControlExpressionLibrary.ParameterByte2, Expression.Constant(0x80)), Expression.Constant(0x01)
)
)
)
);
expressions.Add(Expression.Assign(_programControlExpressionLibrary.ParameterByte2, _programControlExpressionLibrary.ReadAndIncrementProgramCounter));
break;
case InstructionParameterMode.Word:
case InstructionParameterMode.Address:
expressions.Add(Expression.Assign(_programControlExpressionLibrary.ParameterByte2, _programControlExpressionLibrary.ReadAndIncrementProgramCounter));
expressions.Add(Expression.Assign(_programControlExpressionLibrary.ParameterByte1, _programControlExpressionLibrary.ReadAndIncrementProgramCounter));
break;
default:
break;
}
foreach (var advice in _preInstructionAdvice)
{
var a = advice.GetExpression(info, _expressionLibrary);
if (a != null)
expressions.Add(a);
}
expressions.Add(info.Body);
foreach (var advice in _postInstructionAdvice)
{
var a = advice.GetExpression(info, _expressionLibrary);
if (a != null)
expressions.Add(a);
}
if (_postInstructionAdvice.Count > 0)
{
expressions.Add(Expression.Assign(_programControlExpressionLibrary.CycleCounter, _programControlExpressionLibrary.CycleCounter));
}
if (info.Cycles.HasValue)
{
expressions.Add(
Expression.SubtractAssign(
_programControlExpressionLibrary.CycleCounter,
Expression.Constant(info.Cycles)
)
);
}
return Expression.Block(expressions.ToArray());
}
