using System; using System.Reflection; using System.Collections.Generic; using System.Linq; using NLua.Exceptions; using NLua.Extensions; using LuaState = KeraLua.Lua; using LuaNativeFunction = KeraLua.LuaFunction; namespace NLua.Method { /* * Argument extraction with type-conversion function */ delegate object ExtractValue(LuaState luaState, int stackPos); /* * Wrapper class for methods/constructors accessed from Lua. * */ class LuaMethodWrapper { internal LuaNativeFunction InvokeFunction; readonly ObjectTranslator _translator; readonly MethodBase _method; readonly ExtractValue _extractTarget; readonly object _target; readonly bool _isStatic; readonly string _methodName; readonly MethodInfo[] _members; MethodCache _lastCalledMethod; /* * Constructs the wrapper for a known MethodBase instance */ public LuaMethodWrapper(ObjectTranslator translator, object target, ProxyType targetType, MethodBase method) { InvokeFunction = Call; _translator = translator; _target = target; _extractTarget = translator.typeChecker.GetExtractor(targetType); _method = method; _methodName = method.Name; _isStatic = method.IsStatic; } /* * Constructs the wrapper for a known method name */ public LuaMethodWrapper(ObjectTranslator translator, ProxyType targetType, string methodName, BindingFlags bindingType) { InvokeFunction = Call; _translator = translator; _methodName = methodName; _extractTarget = translator.typeChecker.GetExtractor(targetType); _isStatic = (bindingType & BindingFlags.Static) == BindingFlags.Static; _members = GetMethodsRecursively(targetType.UnderlyingSystemType, methodName, bindingType | BindingFlags.Public); } MethodInfo[] GetMethodsRecursively(Type type, string methodName, BindingFlags bindingType) { if (type == typeof(object)) return type.GetMethods(methodName, bindingType); var methods = type.GetMethods(methodName, bindingType); var baseMethods = GetMethodsRecursively(type.BaseType, methodName, bindingType); return methods.Concat(baseMethods).ToArray(); } /// /// Convert C# exceptions into Lua errors /// /// num of things on stack /// null for no pending exception int SetPendingException(Exception e) { return _translator.interpreter.SetPendingException(e); } /* * Calls the method. Receives the arguments from the Lua stack * and returns values in it. */ int Call(IntPtr state) { var luaState = LuaState.FromIntPtr(state); MethodBase methodToCall = _method; object targetObject = _target; bool failedCall = true; int nReturnValues = 0; if (!luaState.CheckStack(5)) throw new LuaException("Lua stack overflow"); bool isStatic = _isStatic; SetPendingException(null); if (methodToCall == null) { // Method from name if (isStatic) targetObject = null; else targetObject = _extractTarget(luaState, 1); if (_lastCalledMethod.cachedMethod != null) { // Cached? int numStackToSkip = isStatic ? 0 : 1; // If this is an instance invoe we will have an extra arg on the stack for the targetObject int numArgsPassed = luaState.GetTop() - numStackToSkip; MethodBase method = _lastCalledMethod.cachedMethod; if (numArgsPassed == _lastCalledMethod.argTypes.Length) { // No. of args match? if (!luaState.CheckStack(_lastCalledMethod.outList.Length + 6)) throw new LuaException("Lua stack overflow"); object[] args = _lastCalledMethod.args; try { for (int i = 0; i < _lastCalledMethod.argTypes.Length; i++) { MethodArgs type = _lastCalledMethod.argTypes[i]; int index = i + 1 + numStackToSkip; if (_lastCalledMethod.argTypes[i].IsParamsArray) { int count = _lastCalledMethod.argTypes.Length - i; Array paramArray = _translator.TableToArray(luaState, type.ExtractValue, type.ParamsArrayType, index, count); args[_lastCalledMethod.argTypes[i].Index] = paramArray; } else { args[type.Index] = type.ExtractValue(luaState, index); } if (_lastCalledMethod.args[_lastCalledMethod.argTypes[i].Index] == null && !luaState.IsNil(i + 1 + numStackToSkip)) throw new LuaException(string.Format("Argument number {0} is invalid", (i + 1))); } if (_isStatic) _translator.Push(luaState, method.Invoke(null, _lastCalledMethod.args)); else { if (method.IsConstructor) _translator.Push(luaState, ((ConstructorInfo)method).Invoke(_lastCalledMethod.args)); else _translator.Push(luaState, method.Invoke(targetObject, _lastCalledMethod.args)); } failedCall = false; } catch (TargetInvocationException e) { // Failure of method invocation if (_translator.interpreter.UseTraceback) e.GetBaseException().Data["Traceback"] = _translator.interpreter.GetDebugTraceback(); return SetPendingException(e.GetBaseException()); } catch (Exception e) { if (_members.Length == 1) // Is the method overloaded? // No, throw error return SetPendingException(e); } } } // Cache miss if (failedCall) { // System.Diagnostics.Debug.WriteLine("cache miss on " + methodName); // If we are running an instance variable, we can now pop the targetObject from the stack if (!isStatic) { if (targetObject == null) { _translator.ThrowError(luaState, string.Format("instance method '{0}' requires a non null target object", _methodName)); luaState.PushNil(); return 1; } luaState.Remove(1); // Pops the receiver } bool hasMatch = false; string candidateName = null; foreach (var member in _members) { candidateName = member.ReflectedType.Name + "." + member.Name; bool isMethod = _translator.MatchParameters(luaState, member, ref _lastCalledMethod); if (isMethod) { hasMatch = true; break; } } if (!hasMatch) { string msg = (candidateName == null) ? "Invalid arguments to method call" : ("Invalid arguments to method: " + candidateName); _translator.ThrowError(luaState, msg); luaState.PushNil(); return 1; } } } else { // Method from MethodBase instance if (methodToCall.ContainsGenericParameters) { _translator.MatchParameters(luaState, methodToCall, ref _lastCalledMethod); if (methodToCall.IsGenericMethodDefinition) { //need to make a concrete type of the generic method definition var typeArgs = new List(); foreach (object arg in _lastCalledMethod.args) typeArgs.Add(arg.GetType()); var concreteMethod = ((MethodInfo)methodToCall).MakeGenericMethod(typeArgs.ToArray()); _translator.Push(luaState, concreteMethod.Invoke(targetObject, _lastCalledMethod.args)); failedCall = false; } else if (methodToCall.ContainsGenericParameters) { _translator.ThrowError(luaState, "Unable to invoke method on generic class as the current method is an open generic method"); luaState.PushNil(); return 1; } } else { if (!methodToCall.IsStatic && !methodToCall.IsConstructor && targetObject == null) { targetObject = _extractTarget(luaState, 1); luaState.Remove(1); // Pops the receiver } if (!_translator.MatchParameters(luaState, methodToCall, ref _lastCalledMethod)) { _translator.ThrowError(luaState, "Invalid arguments to method call"); luaState.PushNil(); return 1; } } } if (failedCall) { if (!luaState.CheckStack(_lastCalledMethod.outList.Length + 6)) throw new LuaException("Lua stack overflow"); try { if (isStatic) _translator.Push(luaState, _lastCalledMethod.cachedMethod.Invoke(null, _lastCalledMethod.args)); else { if (_lastCalledMethod.cachedMethod.IsConstructor) _translator.Push(luaState, ((ConstructorInfo)_lastCalledMethod.cachedMethod).Invoke(_lastCalledMethod.args)); else _translator.Push(luaState, _lastCalledMethod.cachedMethod.Invoke(targetObject, _lastCalledMethod.args)); } } catch (TargetInvocationException e) { if (_translator.interpreter.UseTraceback) e.GetBaseException().Data["Traceback"] = _translator.interpreter.GetDebugTraceback(); return SetPendingException(e.GetBaseException()); } catch (Exception e) { return SetPendingException(e); } } // Pushes out and ref return values for (int index = 0; index < _lastCalledMethod.outList.Length; index++) { nReturnValues++; _translator.Push(luaState, _lastCalledMethod.args[_lastCalledMethod.outList[index]]); } // If not return void,we need add 1, // or we will lost the function's return value // when call dotnet function like "int foo(arg1,out arg2,out arg3)" in Lua code if (!_lastCalledMethod.IsReturnVoid && nReturnValues > 0) nReturnValues++; return nReturnValues < 1 ? 1 : nReturnValues; } } }