public static Instruction EncapsulateWithTryFinally(this ILProcessor ilProcessor)
{
var body = ilProcessor.Body;
var firstInstruction = body.Instructions[0];
var newReturn = ilProcessor.ReplaceReturnsByLeave();
var endFinally = Instruction.Create(OpCodes.Endfinally);
ilProcessor.InsertBefore(newReturn, endFinally);
if (body.Instructions[0].Equals(firstInstruction))
{
Instruction tryStart = Instruction.Create(OpCodes.Nop);
ilProcessor.InsertBefore(firstInstruction, tryStart);
}
Instruction finallyStart = Instruction.Create(OpCodes.Nop);
ilProcessor.InsertBefore(endFinally, finallyStart);
var handler = new ExceptionHandler(ExceptionHandlerType.Finally)
{
TryStart = firstInstruction,
TryEnd = finallyStart,
HandlerStart = finallyStart,
HandlerEnd = newReturn,
};
body.ExceptionHandlers.Add(handler);
return(endFinally);
}