public LabelWrapper DefineLabel()
{
var label = new LabelWrapper();
this.AddInstruction(new ILInstruction(OpCodes.Nop, label, typeof(LabelWrapper), ILInstructionType.DefineLabel));
return(label);
}
public void EmitBreak(OpCode opcode, LabelWrapper label)
{
if (!opcode.Name.StartsWith("b") || opcode == OpCodes.Break || opcode == OpCodes.Box)
{
throw new Exception("Unsupported Opcode, only 'break'-opcodes supported");
}
this.AddInstruction(opcode, label);
}
public void EmitSwitchCases(Type switchType, Type returnType, List <Tuple <object, object> > switchReturnValues)
{
var defaultCase = this.DefineLabel();
var endOfMethod = this.DefineLabel();
var switchValue = this.DeclareLocal(switchType);
this.EmitLocal(OpCodes.Stloc, switchValue);
var jumpTable = new LabelWrapper[switchReturnValues.Count];
for (int i = 0; i < switchReturnValues.Count; i++)
{
jumpTable[i] = this.DefineLabel();
this.EmitLocal(OpCodes.Ldloc, switchValue);
this.EmitLoadEnumValue(switchType, switchReturnValues[i].Item1);
if (switchType == typeof(string))
{
var stringEquals = typeof(string).GetMethod("op_Equality", new[] { typeof(string), typeof(string) });
this.EmitCall(OpCodes.Call, stringEquals);
this.Emit(OpCodes.Ldc_I4_1);
}
this.EmitBreak(OpCodes.Beq, jumpTable[i]);
}
// Branch on default case
this.EmitBreak(OpCodes.Br, defaultCase);
for (int i = 0; i < switchReturnValues.Count; i++)
{
this.MarkLabel(jumpTable[i]);
this.EmitLoadEnumValue(returnType, switchReturnValues[i].Item2);
this.EmitBreak(OpCodes.Br, endOfMethod);
}
// Default case
this.MarkLabel(defaultCase);
this.EmitLoadEnumValue(returnType, switchReturnValues[0].Item2);
this.MarkLabel(endOfMethod);
}
private void AddInstruction(OpCode opcode, LabelWrapper label)
{
this.AddInstruction(new ILInstruction(opcode, label, typeof(LabelWrapper)));
}
public void MarkLabel(LabelWrapper label)
{
this.AddInstruction(new ILInstruction(OpCodes.Nop, label, typeof(LabelWrapper), ILInstructionType.MarkLabel));
}