/// <summary>
/// Python properties may have the following function attributes set to control how they're exposed:
/// - _clr_property_type_ - property type (required)
/// </summary>
/// <param name="propertyName">Property name to add to the type</param>
/// <param name="func">Python property object</param>
/// <param name="typeBuilder">TypeBuilder for the new type the method/property is to be added to</param>
private static void AddPythonProperty(string propertyName, PyObject func, TypeBuilder typeBuilder)
{
// add the method to call back into python
MethodAttributes methodAttribs = MethodAttributes.Public |
MethodAttributes.Virtual |
MethodAttributes.ReuseSlot |
MethodAttributes.HideBySig |
MethodAttributes.SpecialName;
using (PyObject pyPropertyType = func.GetAttr("_clr_property_type_"))
{
Type propertyType = pyPropertyType.AsManagedObject(typeof(Type)) as Type;
if (propertyType == null)
{
throw new ArgumentException("_clr_property_type must be a CLR type");
}
PropertyBuilder propertyBuilder = typeBuilder.DefineProperty(propertyName,
PropertyAttributes.None,
propertyType,
null);
if (func.HasAttr("fget") && func.GetAttr("fget").IsTrue())
{
MethodBuilder methodBuilder = typeBuilder.DefineMethod("get_" + propertyName,
methodAttribs,
propertyType,
null);
ILGenerator il = methodBuilder.GetILGenerator();
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Ldstr, propertyName);
il.Emit(OpCodes.Call, typeof(PythonDerivedType).GetMethod("InvokeGetProperty").MakeGenericMethod(propertyType));
il.Emit(OpCodes.Ret);
propertyBuilder.SetGetMethod(methodBuilder);
}
if (func.HasAttr("fset") && func.GetAttr("fset").IsTrue())
{
MethodBuilder methodBuilder = typeBuilder.DefineMethod("set_" + propertyName,
methodAttribs,
null,
new Type[] { propertyType });
ILGenerator il = methodBuilder.GetILGenerator();
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Ldstr, propertyName);
il.Emit(OpCodes.Ldarg_1);
il.Emit(OpCodes.Call, typeof(PythonDerivedType).GetMethod("InvokeSetProperty").MakeGenericMethod(propertyType));
il.Emit(OpCodes.Ret);
propertyBuilder.SetSetMethod(methodBuilder);
}
}
}
/// <summary>
/// Python method may have the following function attributes set to control how they're exposed:
/// - _clr_return_type_ - method return type (required)
/// - _clr_arg_types_ - list of method argument types (required)
/// - _clr_method_name_ - method name, if different from the python method name (optional)
/// </summary>
/// <param name="methodName">Method name to add to the type</param>
/// <param name="func">Python callable object</param>
/// <param name="typeBuilder">TypeBuilder for the new type the method/property is to be added to</param>
private static void AddPythonMethod(string methodName, PyObject func, TypeBuilder typeBuilder)
{
if (func.HasAttr("_clr_method_name_"))
{
using (PyObject pyMethodName = func.GetAttr("_clr_method_name_"))
{
methodName = pyMethodName.ToString();
}
}
using (PyObject pyReturnType = func.GetAttr("_clr_return_type_"))
using (PyObject pyArgTypes = func.GetAttr("_clr_arg_types_"))
{
var returnType = pyReturnType.AsManagedObject(typeof(Type)) as Type;
if (returnType == null)
{
returnType = typeof(void);
}
if (!pyArgTypes.IsIterable())
{
throw new ArgumentException("_clr_arg_types_ must be a list or tuple of CLR types");
}
var argTypes = new List <Type>();
foreach (PyObject pyArgType in pyArgTypes)
{
var argType = pyArgType.AsManagedObject(typeof(Type)) as Type;
if (argType == null)
{
throw new ArgumentException("_clr_arg_types_ must be a list or tuple of CLR types");
}
argTypes.Add(argType);
}
// add the method to call back into python
MethodAttributes methodAttribs = MethodAttributes.Public |
MethodAttributes.Virtual |
MethodAttributes.ReuseSlot |
MethodAttributes.HideBySig;
MethodBuilder methodBuilder = typeBuilder.DefineMethod(methodName,
methodAttribs,
returnType,
argTypes.ToArray());
ILGenerator il = methodBuilder.GetILGenerator();
il.DeclareLocal(typeof(object[]));
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Ldstr, methodName);
il.Emit(OpCodes.Ldnull); // don't fall back to the base type's method
il.Emit(OpCodes.Ldc_I4, argTypes.Count);
il.Emit(OpCodes.Newarr, typeof(object));
il.Emit(OpCodes.Stloc_0);
for (var i = 0; i < argTypes.Count; ++i)
{
il.Emit(OpCodes.Ldloc_0);
il.Emit(OpCodes.Ldc_I4, i);
il.Emit(OpCodes.Ldarg, i + 1);
if (argTypes[i].IsValueType)
{
il.Emit(OpCodes.Box, argTypes[i]);
}
il.Emit(OpCodes.Stelem, typeof(object));
}
il.Emit(OpCodes.Ldloc_0);
if (returnType == typeof(void))
{
il.Emit(OpCodes.Call, typeof(PythonDerivedType).GetMethod("InvokeMethodVoid"));
}
else
{
il.Emit(OpCodes.Call,
typeof(PythonDerivedType).GetMethod("InvokeMethod").MakeGenericMethod(returnType));
}
il.Emit(OpCodes.Ret);
}
}
/// <summary>
/// Creates a new managed type derived from a base type with any virtual
/// methods overridden to call out to python if the associated python
/// object has overridden the method.
/// </summary>
internal static Type CreateDerivedType(string name,
Type baseType,
BorrowedReference dictRef,
string namespaceStr,
string assemblyName,
string moduleName = "Python.Runtime.Dynamic.dll")
{
// TODO: clean up
IntPtr py_dict = dictRef.DangerousGetAddress();
if (null != namespaceStr)
{
name = namespaceStr + "." + name;
}
if (null == assemblyName)
{
assemblyName = "Python.Runtime.Dynamic";
}
ModuleBuilder moduleBuilder = GetModuleBuilder(assemblyName, moduleName);
Type baseClass = baseType;
var interfaces = new List <Type> {
typeof(IPythonDerivedType)
};
// if the base type is an interface then use System.Object as the base class
// and add the base type to the list of interfaces this new class will implement.
if (baseType.IsInterface)
{
interfaces.Add(baseType);
baseClass = typeof(object);
}
TypeBuilder typeBuilder = moduleBuilder.DefineType(name,
TypeAttributes.Public | TypeAttributes.Class,
baseClass,
interfaces.ToArray());
// add a field for storing the python object pointer
// FIXME: fb not used
FieldBuilder fb = typeBuilder.DefineField("__pyobj__", typeof(CLRObject), FieldAttributes.Public);
// override any constructors
ConstructorInfo[] constructors = baseClass.GetConstructors();
foreach (ConstructorInfo ctor in constructors)
{
AddConstructor(ctor, baseType, typeBuilder);
}
// Override any properties explicitly overridden in python
var pyProperties = new HashSet <string>();
if (py_dict != IntPtr.Zero && Runtime.PyDict_Check(py_dict))
{
Runtime.XIncref(py_dict);
using (var dict = new PyDict(py_dict))
using (PyObject keys = dict.Keys())
{
foreach (PyObject pyKey in keys)
{
using (PyObject value = dict[pyKey])
{
if (value.HasAttr("_clr_property_type_"))
{
string propertyName = pyKey.ToString();
pyProperties.Add(propertyName);
// Add the property to the type
AddPythonProperty(propertyName, value, typeBuilder);
}
}
}
}
}
// override any virtual methods not already overridden by the properties above
MethodInfo[] methods = baseType.GetMethods();
var virtualMethods = new HashSet <string>();
foreach (MethodInfo method in methods)
{
if (!method.Attributes.HasFlag(MethodAttributes.Virtual) |
method.Attributes.HasFlag(MethodAttributes.Final))
{
continue;
}
// skip if this property has already been overridden
if ((method.Name.StartsWith("get_") || method.Name.StartsWith("set_")) &&
pyProperties.Contains(method.Name.Substring(4)))
{
continue;
}
// keep track of the virtual methods redirected to the python instance
virtualMethods.Add(method.Name);
// override the virtual method to call out to the python method, if there is one.
AddVirtualMethod(method, baseType, typeBuilder);
}
// Add any additional methods and properties explicitly exposed from Python.
if (py_dict != IntPtr.Zero && Runtime.PyDict_Check(py_dict))
{
Runtime.XIncref(py_dict);
using (var dict = new PyDict(py_dict))
using (PyObject keys = dict.Keys())
{
foreach (PyObject pyKey in keys)
{
using (PyObject value = dict[pyKey])
{
if (value.HasAttr("_clr_return_type_") && value.HasAttr("_clr_arg_types_"))
{
string methodName = pyKey.ToString();
// if this method has already been redirected to the python method skip it
if (virtualMethods.Contains(methodName))
{
continue;
}
// Add the method to the type
AddPythonMethod(methodName, value, typeBuilder);
}
}
}
}
}
// add the destructor so the python object created in the constructor gets destroyed
MethodBuilder methodBuilder = typeBuilder.DefineMethod("Finalize",
MethodAttributes.Family |
MethodAttributes.Virtual |
MethodAttributes.HideBySig,
CallingConventions.Standard,
typeof(void),
Type.EmptyTypes);
ILGenerator il = methodBuilder.GetILGenerator();
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Call, typeof(PythonDerivedType).GetMethod("Finalize"));
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Call, baseClass.GetMethod("Finalize", BindingFlags.NonPublic | BindingFlags.Instance));
il.Emit(OpCodes.Ret);
Type type = typeBuilder.CreateType();
// scan the assembly so the newly added class can be imported
Assembly assembly = Assembly.GetAssembly(type);
AssemblyManager.ScanAssembly(assembly);
// FIXME: assemblyBuilder not used
AssemblyBuilder assemblyBuilder = assemblyBuilders[assemblyName];
return(type);
}
