static void AddField(ModuleDefinition module, NewFieldData newField)
{
var fieldType = GenTypes.GetTypeInAnyAssembly(newField.fieldType);
var ceFieldType = module.ImportReference(fieldType);
PrepatcherMod.Info($"Patching in a new field {newField.name} of type {ceFieldType.ToStringSafe()}/{newField.fieldType} in type {newField.targetType}");
var ceField = new FieldDefinition(
newField.name,
FieldAttributes.Public,
ceFieldType
);
if (newField.isStatic)
{
ceField.Attributes |= FieldAttributes.Static;
}
var targetType = module.GetType(newField.targetType);
targetType.Fields.Add(ceField);
if (newField.defaultValue != null)
{
WriteFieldInitializers(newField, ceField, fieldType);
}
}
static void WriteFieldInitializers(NewFieldData newField, FieldDefinition ceNewField, Type fieldType)
{
var targetType = ceNewField.DeclaringType;
var i = targetType.Fields.IndexOf(ceNewField);
foreach (var ctor in targetType.GetConstructors().Where(c => c.IsStatic == newField.isStatic))
{
if (Util.CallsAThisCtor(ctor))
{
continue;
}
var insts = (IList <Instruction>)ctor.Body.Instructions;
int insertAt = -1;
int lastValid = -1;
for (int k = 0; k < insts.Count; k++)
{
var inst = insts[k];
insertAt = lastValid;
if (inst.OpCode == OpCodes.Call && inst.Operand is MethodDefinition m && m.IsConstructor)
{
break;
}
if (inst.OpCode == OpCodes.Stfld && inst.Operand is FieldDefinition f)
{
if (targetType.Fields.IndexOf(f) > i)
{
break;
}
lastValid = k;
}
}
insertAt++;
var ilProc = ctor.Body.GetILProcessor();
var insertBefore = insts[insertAt];
if (!newField.isStatic)
{
ilProc.InsertBefore(insertBefore, Instruction.Create(OpCodes.Ldarg_0));
}
if (newField.defaultValue == NewFieldData.DEFAULT_VALUE_NEW_CTOR)
{
ilProc.InsertBefore(insertBefore, Instruction.Create(OpCodes.Newobj, targetType.Module.ImportReference(fieldType.GetConstructor(new Type[0]))));
}
else
{
var defaultValueInst = Instruction.Create(OpCodes.Ret);
var op = Util.GetConstantOpCode(newField.defaultValue).Value;
defaultValueInst.OpCode = op;
defaultValueInst.Operand = op == OpCodes.Ldc_I4 ? Convert.ToInt32(newField.defaultValue) : newField.defaultValue;
ilProc.InsertBefore(insertBefore, defaultValueInst);
}
ilProc.InsertBefore(insertBefore, Instruction.Create(newField.isStatic ? OpCodes.Stsfld : OpCodes.Stfld, ceNewField));
}
}
