private static void ProcessEachInstruction(ModuleDefinition systemModuleDefinition, Instruction loadTokenInstruction, ScopedProcessor processor, ModuleDefinition moduleDefinition)
{
if (!IsValidLoadTokenInstruction(loadTokenInstruction, out var enumTypeReference) || !enumTypeReference.TryToDefinition(out var enumTypeDefinition) || !enumTypeDefinition.IsEnum)
{
return;
}
var getTypeFromHandleInstruction = loadTokenInstruction.Next;
if (getTypeFromHandleInstruction is null || getTypeFromHandleInstruction.OpCode.Code != Code.Call || !(getTypeFromHandleInstruction.Operand is MethodReference getTypeFromHandleMethodReference) || getTypeFromHandleMethodReference.FullName != "System.Type System.Type::GetTypeFromHandle(System.RuntimeTypeHandle)")
{
return;
}
var getValuesInstruction = getTypeFromHandleInstruction.Next;
if (getValuesInstruction is null || getValuesInstruction.OpCode != OpCodes.Call || !(getValuesInstruction.Operand is MethodReference methodReference) || methodReference.FullName != "System.Array System.Enum::GetValues(System.Type)")
{
return;
}
var castClassOrIsInstInstruction = getValuesInstruction.Next;
var enumsGetValuesInstructions = moduleDefinition.EnumGetValuesInstructions(enumTypeDefinition, systemModuleDefinition);
if (!(castClassOrIsInstInstruction is null) && (castClassOrIsInstInstruction.OpCode == OpCodes.Isinst || castClassOrIsInstInstruction.OpCode == OpCodes.Castclass))
{
var castTargetClass = (TypeReference)castClassOrIsInstInstruction.Operand;
switch (enumsGetValuesInstructions.Length)
{
case 0: return;
case 1:
processor
.Replace(loadTokenInstruction, enumsGetValuesInstructions[0])
.Remove(getTypeFromHandleInstruction)
.Remove(getValuesInstruction);
if (castTargetClass.GetElementType().FullName == enumTypeDefinition.FullName)
{
processor.Remove(castClassOrIsInstInstruction);
}
break;
case 2:
processor
.Replace(loadTokenInstruction, enumsGetValuesInstructions[0])
.Replace(getTypeFromHandleInstruction, enumsGetValuesInstructions[1])
.Remove(getValuesInstruction);
if (castTargetClass.GetElementType().FullName == enumTypeDefinition.FullName)
{
processor.Remove(castClassOrIsInstInstruction);
}
break;
case 3:
processor
.Replace(loadTokenInstruction, enumsGetValuesInstructions[0])
.Replace(getTypeFromHandleInstruction, enumsGetValuesInstructions[1])
.Replace(getValuesInstruction, enumsGetValuesInstructions[2]);
if (castTargetClass.GetElementType().FullName == enumTypeDefinition.FullName)
{
processor.Remove(castClassOrIsInstInstruction);
}
break;
default:
processor
.Replace(loadTokenInstruction, enumsGetValuesInstructions[0])
.Replace(getTypeFromHandleInstruction, enumsGetValuesInstructions[1])
.Replace(getValuesInstruction, enumsGetValuesInstructions[2]);
if (castTargetClass.GetElementType().FullName == enumTypeDefinition.FullName)
{
processor.Replace(castClassOrIsInstInstruction, enumsGetValuesInstructions[3]);
for (var i = 4; i < enumsGetValuesInstructions.Length; i++)
{
processor.InsertAfter(enumsGetValuesInstructions[i - 1], enumsGetValuesInstructions[i]);
}
}
else
{
for (var i = 3; i < enumsGetValuesInstructions.Length; i++)
{
processor.InsertAfter(enumsGetValuesInstructions[i - 1], enumsGetValuesInstructions[i]);
}
}
break;
}
}