private void WeaveOnExecute(MethodDefinition targetMethod, ILProcessor ilp, VariableDefinition aspectInstance, VariableDefinition correlation, Instruction addAfter)
{
if (_onExecute != null)
{
var onExecInstructions = GetOnExecuteInstructions(targetMethod, ilp, aspectInstance, correlation);
if (addAfter == null)
{
ilp.PrependInstructions(onExecInstructions);
}
else
{
ilp.InsertInstructionsAfter(addAfter, onExecInstructions);
}
}
}
private void WeaveOnException(MethodDefinition targetMethod, ILProcessor ilp, VariableDefinition aspectInstance, VariableDefinition correlation, Instruction addAfter)
{
if (_onException != null)
{
targetMethod.Body.InitLocals = true;
var exceptionType = targetMethod.Module.Import(typeof(Exception));
var onExceptionInstructions = GetOnExceptionInstructions(targetMethod, ilp, aspectInstance, correlation, exceptionType).ToArray();
var tryEnd = ilp.Body.Instructions.Last();
var returns = false;
if (tryEnd.OpCode == OpCodes.Ret)
{
returns = true;
var nopOrLoad = tryEnd.Previous;
if (nopOrLoad.OpCode == OpCodes.Nop)
{
var leaveToNop = ilp.Create(OpCodes.Leave_S, nopOrLoad);
ilp.InsertBefore(nopOrLoad, leaveToNop);
tryEnd = nopOrLoad;
}
else
{
var nopOrBreak = nopOrLoad.Previous;
if (nopOrBreak.OpCode == OpCodes.Br_S)
{
var nop = ilp.Create(OpCodes.Nop);
ilp.InsertBefore(nopOrBreak, nop);
ilp.Remove(nopOrBreak);
var leave = ilp.Create(OpCodes.Leave_S, nop);
ilp.InsertBefore(nop, leave);
tryEnd = nop;
}
else
{
tryEnd = nopOrBreak;
}
}
}
else
{
var nop = ilp.Create(OpCodes.Nop);
ilp.Append(nop);
tryEnd = nop;
}
var insertPoint = tryEnd.Previous;
ilp.InsertInstructionsAfter(insertPoint, onExceptionInstructions);
if (!returns)
{
ilp.Remove(tryEnd);
}
tryEnd = insertPoint.Next;
var exceptionHandler = new ExceptionHandler(ExceptionHandlerType.Catch)
{
TryStart = addAfter != null
? addAfter.Next
: ilp.Body.Instructions.First(),
TryEnd = tryEnd,
HandlerStart = tryEnd,
HandlerEnd = returns
? onExceptionInstructions.Last().Next
: null,
CatchType = exceptionType
};
targetMethod.Body.ExceptionHandlers.Add(exceptionHandler);
}
}