private void Emit(Expression exp)
{
OpCode op;
switch (exp)
{
case BinaryExpression be:
if (exp.NodeType == ExpressionType.Assign)
{
EmitAssign(be);
break;
}
Emit(be.Left);
Emit(be.Right);
switch (exp.NodeType)
{
case ExpressionType.ArrayIndex:
_ilg.Ldelem(be.Left.Type.GetElementType());
break;
case ExpressionType.RightShift:
_ilg.Emit(
new Instruction(be.Left.Type.IsUnsigned() ? OpCodes.Shr_Un : OpCodes.Shr));
break;
default:
if (Expr2Op.TryGetValue(exp.NodeType, out op))
{
_ilg.Emit(new Instruction(op));
}
else
{
throw new NotSupportedException();
}
break;
}
break;
case IndexExpression ie:
Emit(ie.Object);
break;
case UnaryExpression ue:
Emit(ue.Operand);
if (Expr2Op.TryGetValue(exp.NodeType, out op))
{
_ilg.Emit(new Instruction(op));
}
else
{
throw new NotSupportedException();
}
break;
case ConstantExpression ce:
_ilg.Const(ce.Value, ce.Type);
break;
case ParameterExpression pe:
var local = ParameterResolver?.Invoke(pe);
if (local != null)
{
_ilg.Emit(Instruction.Create(OpCodes.Ldloc, local));
}
// else assume parameter is on stack and do nothing
break;
default:
throw new NotSupportedException();
}
}
public override void Load(IILEmitter emitter)
{
Array.Load(emitter);
emitter.Const(Index);
emitter.Ldelem(Array.Type.Next);
}
