/// <summary>
/// Parses the instruction.
/// </summary>
/// <param name="mainProcessor">The main instruction processor.</param>
/// <param name="asmCollection">The papyrus assembly collection.</param>
/// <param name="instruction">The instruction.</param>
/// <param name="targetMethod">The target method.</param>
/// <param name="targetType">Type of the target.</param>
/// <returns></returns>
/// <exception cref="StackUnderflowException"></exception>
public IEnumerable <PapyrusInstruction> Process(
IClrInstructionProcessor mainProcessor,
IReadOnlyCollection <PapyrusAssemblyDefinition> asmCollection,
Instruction instruction,
MethodDefinition targetMethod,
TypeDefinition targetType)
{
bool isStructAccess;
var structGets = new List <PapyrusInstruction>();
this.papyrusAssemblyCollection = asmCollection;
var processInstruction = new List <PapyrusInstruction>();
var stack = mainProcessor.EvaluationStack;
currentInstruction = instruction;
var methodRef = instruction.Operand as MethodReference;
if (methodRef != null)
{
if (methodRef.FullName.ToLower().Contains("system.void") &&
methodRef.FullName.ToLower().Contains(".ctor"))
{
return(new PapyrusInstruction[0]);
}
// What we need:
// 1. Call Location (The name of the type that has this method)
// 2. Method Name (The name of the method, duh)
// 3. Method Parameters (The parameters that we need to pass to the method)
// 4. Destination Variable (The variable needed to store the return value of the method)
// - Destination Variable must always exist, the difference between a function returning a object
// and a void, is that we "assign" the destination to a ::nonevar temp variable of type None (void)
var name = methodRef.FullName;
var itemsToPop = instruction.OpCode.StackBehaviourPop == StackBehaviour.Varpop
? methodRef.Parameters.Count
: Utility.GetStackPopCount(instruction.OpCode.StackBehaviourPop);
if (stack.Count < itemsToPop)
{
if (mainProcessor.PapyrusCompilerOptions == PapyrusCompilerOptions.Strict)
{
throw new StackUnderflowException(targetMethod, instruction);
}
return(processInstruction);
}
// Check if the current invoked Method is inside the same instance of this type
// by checking if it is using "this.Method(params);" << "this."...
var isThisCall = false;
var isStaticCall = false;
var callerLocation = "";
var parameters = new List <object>();
if (methodRef.HasThis)
{
callerLocation = "self";
isThisCall = true;
}
for (var paramIndex = 0; paramIndex < itemsToPop; paramIndex++)
{
var parameter = stack.Pop();
if (parameter.IsThis && stack.Count > methodRef.Parameters.Count ||
methodRef.CallingConvention == MethodCallingConvention.ThisCall)
{
isThisCall = true;
callerLocation = "self"; // Location: 'self' is the same as 'this'
}
parameters.Insert(0, parameter);
}
var methodDefinition = mainProcessor.TryResolveMethodReference(methodRef);
if (methodDefinition != null)
{
isStaticCall = methodDefinition.IsStatic;
}
if (methodDefinition != null && methodDefinition.IsConstructor)
{
return(processInstruction);
}
if (methodDefinition == null)
{
isStaticCall = name.Contains("::");
}
if (isStaticCall)
{
callerLocation = name.Split("::")[0];
}
if (callerLocation.Contains("."))
{
callerLocation = callerLocation.Split('.').LastOrDefault();
}
if (methodRef.Name.ToLower().Contains("concat"))
{
processInstruction.AddRange(mainProcessor.ProcessStringConcat(instruction, methodRef,
parameters));
}
else if (methodRef.Name.ToLower().Contains("op_equal") ||
methodRef.Name.ToLower().Contains("op_inequal"))
{
// TODO: Add Equality comparison
mainProcessor.InvertedBranch = methodRef.Name.ToLower().Contains("op_inequal");
if (!InstructionHelper.IsStore(instruction.Next.OpCode.Code))
{
mainProcessor.SkipToOffset = instruction.Next.Offset;
return(processInstruction);
}
// EvaluationStack.Push(new EvaluationStackItem { IsMethodCall = true, Value = methodRef, TypeName = methodRef.ReturnType.FullName });
processInstruction.AddRange(mainProcessor.ProcessConditionalInstruction(instruction,
Code.Ceq));
}
else
{
if (methodRef.Name.ToLower().StartsWith("get_") || methodRef.Name.ToLower().StartsWith("set_"))
{
processInstruction.AddRange(ProcessPropertyAccess(mainProcessor, instruction, methodRef, methodDefinition,
parameters));
return(processInstruction);
}
if (isStaticCall)
{
var destinationVariable = mainProcessor.GetTargetVariable(instruction, methodRef,
out isStructAccess);
{
processInstruction.Add(CreatePapyrusCallInstruction(mainProcessor, PapyrusOpCodes.Callstatic, methodRef,
callerLocation,
destinationVariable, parameters, out structGets));
processInstruction.InsertRange(processInstruction.Count - 1, structGets);
return(processInstruction);
}
}
if (isThisCall)
{
var isDelegateInvoke = false;
if (stack.Count > 0)
{
var next = stack.Peek().Value;
var varRef = next as PapyrusVariableReference;
if (varRef != null && varRef.IsDelegateReference)
{
isDelegateInvoke = true;
}
}
var destinationVariable = mainProcessor.GetTargetVariable(instruction, methodRef,
out isStructAccess);
if (isDelegateInvoke)
{
var targetDelegate = stack.Pop().Value as PapyrusVariableReference;
var targetDelegateMethodName = targetDelegate.DelegateInvokeReference;
// In case we are invoking a delegate from inside a delegate then we need to find the
// reference to the previous delegate method and use that one instead.
var target = InstructionHelper.FindPreviousInstruction(instruction,
InstructionHelper.IsLoadMethodRef);
if (target != null && target.Operand is MethodReference)
{
methodRef = target.Operand as MethodReference;
targetDelegateMethodName = methodRef.Name;
}
processInstruction.Add(CreatePapyrusCallInstruction(mainProcessor, PapyrusOpCodes.Callmethod, methodRef,
callerLocation, destinationVariable, parameters, out structGets,
targetDelegateMethodName));
processInstruction.InsertRange(processInstruction.Count - 1, structGets);
}
else
{
if (isStructAccess)
{
var structRef =
stack.Pop().Value as PapyrusStructFieldReference;
if (structRef != null)
{
// (Call and Assign Temp then do StructSet using Temp)
// Call and Assign return value to temp
processInstruction.Add(CreatePapyrusCallInstruction(mainProcessor, PapyrusOpCodes.Callmethod,
methodRef,
callerLocation,
destinationVariable, parameters, out structGets));
// StructSet
processInstruction.Add(
mainProcessor.CreatePapyrusInstruction(PapyrusOpCodes.StructSet,
structRef.StructSource, structRef.StructVariable,
mainProcessor.CreateVariableReferenceFromName(destinationVariable)));
// Skip next instruction as it should be stfld and we already store the field here.
mainProcessor.SkipNextInstruction = true;
}
}
else
{
processInstruction.Add(CreatePapyrusCallInstruction(mainProcessor, PapyrusOpCodes.Callmethod, methodRef,
callerLocation,
destinationVariable, parameters, out structGets));
processInstruction.InsertRange(processInstruction.Count - 1, structGets);
}
}
return(processInstruction);
}
}
}
return(processInstruction);
}
