internal static Instruction FixReturns(this ILProcessor ilProcessor)
{
var methodDefinition = ilProcessor.Body.Method;
if (methodDefinition.ReturnType == methodDefinition.Module.TypeSystem.Void)
{
var instructions = ilProcessor.Body.Instructions.ToArray();
var newReturnInstruction = ilProcessor.Create(OpCodes.Ret);
ilProcessor.Append(newReturnInstruction);
foreach (var instruction in instructions)
{
if (instruction.OpCode == OpCodes.Ret)
{
var leaveInstruction = ilProcessor.Create(OpCodes.Leave, newReturnInstruction);
ilProcessor.Replace(instruction, leaveInstruction);
ilProcessor.ReplaceInstructionReferences(instruction, leaveInstruction);
}
}
return(newReturnInstruction);
}
else
{
var instructions = ilProcessor.Body.Instructions.ToArray();
var returnVariable = new VariableDefinition(methodDefinition.ReturnType);
ilProcessor.Body.Variables.Add(returnVariable);
var loadResultInstruction = ilProcessor.Create(OpCodes.Ldloc, returnVariable);
ilProcessor.Append(loadResultInstruction);
var newReturnInstruction = ilProcessor.Create(OpCodes.Ret);
ilProcessor.Append(newReturnInstruction);
foreach (var instruction in instructions)
{
if (instruction.OpCode == OpCodes.Ret)
{
var saveResultInstruction = ilProcessor.Create(OpCodes.Stloc, returnVariable);
ilProcessor.Replace(instruction, saveResultInstruction);
var leaveInstruction = ilProcessor.Create(OpCodes.Leave, loadResultInstruction);
ilProcessor.InsertAfter(saveResultInstruction, leaveInstruction);
ilProcessor.ReplaceInstructionReferences(instruction, leaveInstruction);
}
}
return(loadResultInstruction);
}
}
internal static void RemoveTailInstructions(this ILProcessor ilProcessor)
{
foreach (var instruction in ilProcessor.Body.Instructions.ToArray())
{
if (instruction.OpCode == OpCodes.Tail)
{
var noOpInstruction = ilProcessor.Create(OpCodes.Nop);
ilProcessor.Replace(instruction, noOpInstruction);
ilProcessor.ReplaceInstructionReferences(instruction, noOpInstruction);
}
}
}
public static Instruction InsertBefore(
this ILProcessor ilProcessor,
Instruction target,
IEnumerable <Instruction> newInstructions,
bool updateReferences)
{
var newTarget = target;
foreach (var instruction in newInstructions.Reverse())
{
ilProcessor.InsertBefore(newTarget, instruction);
newTarget = instruction;
}
if (updateReferences)
{
ilProcessor.ReplaceInstructionReferences(target, newTarget);
}
return(newTarget);
}
