private Type GenerateDelegate(Type delegateType)
{
string typeName;
lock(this)
{
typeName = "LuaGeneratedClass" + luaClassNumber;
luaClassNumber++;
}
// Define a public class in the assembly, called typeName
TypeBuilder myType=newModule.DefineType(typeName,TypeAttributes.Public,delegateParent);
// Defines the delegate method with the same signature as the
// Invoke method of delegateType
MethodInfo invokeMethod=delegateType.GetMethod("Invoke");
ParameterInfo[] paramInfo=invokeMethod.GetParameters();
Type[] paramTypes=new Type[paramInfo.Length];
Type returnType=invokeMethod.ReturnType;
// Counts out and ref params, for use later
int nOutParams=0; int nOutAndRefParams=0;
for(int i=0;i<paramTypes.Length;i++)
{
paramTypes[i]=paramInfo[i].ParameterType;
if((!paramInfo[i].IsIn) && paramInfo[i].IsOut)
nOutParams++;
if(paramTypes[i].IsByRef)
nOutAndRefParams++;
}
int[] refArgs=new int[nOutAndRefParams];
MethodBuilder delegateMethod=myType.DefineMethod("CallFunction",
invokeMethod.Attributes,
returnType,paramTypes);
// Generates the IL for the method
ILGenerator generator=delegateMethod.GetILGenerator( );
generator.DeclareLocal(typeof(object[])); // original arguments
generator.DeclareLocal(typeof(object[])); // with out-only arguments removed
generator.DeclareLocal(typeof(int[])); // indexes of out and ref arguments
if(!(returnType == typeof(void))) // return value
generator.DeclareLocal(returnType);
else
generator.DeclareLocal(typeof(object));
// Initializes local variables
generator.Emit(OpCodes.Ldc_I4,paramTypes.Length);
generator.Emit(OpCodes.Newarr,typeof(object));
generator.Emit(OpCodes.Stloc_0);
generator.Emit(OpCodes.Ldc_I4,paramTypes.Length-nOutParams);
generator.Emit(OpCodes.Newarr,typeof(object));
generator.Emit(OpCodes.Stloc_1);
generator.Emit(OpCodes.Ldc_I4,nOutAndRefParams);
generator.Emit(OpCodes.Newarr,typeof(int));
generator.Emit(OpCodes.Stloc_2);
// Stores the arguments in the local variables
for(int iArgs=0,iInArgs=0,iOutArgs=0;iArgs<paramTypes.Length;iArgs++)
{
generator.Emit(OpCodes.Ldloc_0);
generator.Emit(OpCodes.Ldc_I4,iArgs);
generator.Emit(OpCodes.Ldarg,iArgs+1);
if(paramTypes[iArgs].IsByRef)
{
if(paramTypes[iArgs].GetElementType().IsValueType)
{
generator.Emit(OpCodes.Ldobj,paramTypes[iArgs].GetElementType());
generator.Emit(OpCodes.Box,paramTypes[iArgs].GetElementType());
} else generator.Emit(OpCodes.Ldind_Ref);
}
else
{
if(paramTypes[iArgs].IsValueType)
generator.Emit(OpCodes.Box,paramTypes[iArgs]);
}
generator.Emit(OpCodes.Stelem_Ref);
if(paramTypes[iArgs].IsByRef)
{
generator.Emit(OpCodes.Ldloc_2);
generator.Emit(OpCodes.Ldc_I4,iOutArgs);
generator.Emit(OpCodes.Ldc_I4,iArgs);
generator.Emit(OpCodes.Stelem_I4);
refArgs[iOutArgs]=iArgs;
iOutArgs++;
}
if(paramInfo[iArgs].IsIn || (!paramInfo[iArgs].IsOut))
{
generator.Emit(OpCodes.Ldloc_1);
generator.Emit(OpCodes.Ldc_I4,iInArgs);
generator.Emit(OpCodes.Ldarg,iArgs+1);
if(paramTypes[iArgs].IsByRef)
{
if(paramTypes[iArgs].GetElementType().IsValueType)
{
generator.Emit(OpCodes.Ldobj,paramTypes[iArgs].GetElementType());
generator.Emit(OpCodes.Box,paramTypes[iArgs].GetElementType());
}
else generator.Emit(OpCodes.Ldind_Ref);
}
else
{
if(paramTypes[iArgs].IsValueType)
generator.Emit(OpCodes.Box,paramTypes[iArgs]);
}
generator.Emit(OpCodes.Stelem_Ref);
iInArgs++;
}
}
// Calls the callFunction method of the base class
generator.Emit(OpCodes.Ldarg_0);
generator.Emit(OpCodes.Ldloc_0);
generator.Emit(OpCodes.Ldloc_1);
generator.Emit(OpCodes.Ldloc_2);
MethodInfo miGenericEventHandler;
miGenericEventHandler=delegateParent.GetMethod("callFunction");
generator.Emit(OpCodes.Call,miGenericEventHandler);
// Stores return value
if(returnType == typeof(void))
{
generator.Emit(OpCodes.Pop);
generator.Emit(OpCodes.Ldnull);
}
else if(returnType.IsValueType)
{
generator.Emit(OpCodes.Unbox,returnType);
generator.Emit(OpCodes.Ldobj,returnType);
} else generator.Emit(OpCodes.Castclass,returnType);
generator.Emit(OpCodes.Stloc_3);
// Stores new value of out and ref params
for(int i=0;i<refArgs.Length;i++)
{
generator.Emit(OpCodes.Ldarg,refArgs[i]+1);
generator.Emit(OpCodes.Ldloc_0);
generator.Emit(OpCodes.Ldc_I4,refArgs[i]);
generator.Emit(OpCodes.Ldelem_Ref);
if(paramTypes[refArgs[i]].GetElementType().IsValueType)
{
generator.Emit(OpCodes.Unbox,paramTypes[refArgs[i]].GetElementType());
generator.Emit(OpCodes.Ldobj,paramTypes[refArgs[i]].GetElementType());
generator.Emit(OpCodes.Stobj,paramTypes[refArgs[i]].GetElementType());
}
else
{
generator.Emit(OpCodes.Castclass,paramTypes[refArgs[i]].GetElementType());
generator.Emit(OpCodes.Stind_Ref);
}
}
// Returns
if(!(returnType == typeof(void)))
generator.Emit(OpCodes.Ldloc_3);
generator.Emit(OpCodes.Ret);
// creates the new type
return myType.CreateType();
}
