better support for multiple inheritance

pythonnet · rmadsen-ks · Apr 27, 2022 · Apr 28, 2022 · Apr 29, 2022 · May 3, 2022
commit a2c80cd7f567c42b2dc480be53a7fe2619e5fe3b
diff --git a/src/python_tests_runner/PythonTestRunner.cs b/src/python_tests_runner/PythonTestRunner.cs
@@ -17,6 +17,8 @@ public class PythonTestRunner
         [OneTimeSetUp]
         public void SetUp()
         {
+            Python.Runtime.Runtime.PythonDLL =
+                "/Library/Frameworks/Python.framework/Versions/3.10/lib/libpython3.10.dylib";
             PythonEngine.Initialize();
         }
 
@@ -35,6 +37,8 @@ static IEnumerable<string[]> PythonTestCases()
             // Add the test that you want to debug here.
             yield return new[] { "test_indexer", "test_boolean_indexer" };
             yield return new[] { "test_delegate", "test_bool_delegate" };
+            yield return new[] { "test_subclass", "test_virtual_generic_method" };
+            yield return new[] { "test_subclass", "test_interface_and_class_impl2" };
         }
 
         /// <summary>

diff --git a/src/runtime/Runtime.cs b/src/runtime/Runtime.cs
@@ -1833,6 +1833,12 @@ internal static void SetNoSiteFlag()
                 return *Delegates.Py_NoSiteFlag;
             });
         }
+
+        internal static uint PyTuple_GetSize(BorrowedReference tuple)
+        {
+            IntPtr r = Delegates.PyTuple_Size(tuple);
+            return (uint)r.ToInt32();
+        }
     }
 
     internal class BadPythonDllException : MissingMethodException

diff --git a/src/runtime/StateSerialization/MaybeType.cs b/src/runtime/StateSerialization/MaybeType.cs
@@ -15,7 +15,6 @@ internal struct MaybeType : ISerializable
         const string SerializationName = "n";
         readonly string name;
         readonly Type type;
-
         public string DeletedMessage
         {
             get
@@ -38,6 +37,7 @@ public Type Value
 
         public string Name => name;
         public bool Valid => type != null;
+        public Type ValueOrNull => type;
 
         public override string ToString()
         {
@@ -61,4 +61,4 @@ public void GetObjectData(SerializationInfo serializationInfo, StreamingContext
             serializationInfo.AddValue(SerializationName, name);
         }
     }
-}
+}
diff --git a/src/runtime/TypeManager.cs b/src/runtime/TypeManager.cs
@@ -374,7 +374,7 @@ static PyTuple GetBaseTypeTuple(Type clrType)
             return new PyTuple(bases);
         }
 
-        internal static NewReference CreateSubType(BorrowedReference py_name, BorrowedReference py_base_type, BorrowedReference dictRef)
+        internal static NewReference CreateSubType(BorrowedReference py_name, IEnumerable<ClassBase> py_base_type, IEnumerable<Type> interfaces, BorrowedReference dictRef)
         {
             // Utility to create a subtype of a managed type with the ability for the
             // a python subtype able to override the managed implementation
@@ -415,9 +415,10 @@ internal static NewReference CreateSubType(BorrowedReference py_name, BorrowedRe
             }
 
             // create the new managed type subclassing the base managed type
-            if (ManagedType.GetManagedObject(py_base_type) is ClassBase baseClass)
+            var baseClass = py_base_type.FirstOrDefault();
+            if (null == baseClass)
             {
-                return ReflectedClrType.CreateSubclass(baseClass, name,
+                return ReflectedClrType.CreateSubclass(baseClass, interfaces, name,
                                                        ns: (string?)namespaceStr,
                                                        assembly: (string?)assembly,
                                                        dict: dictRef);

diff --git a/src/runtime/Types/ClassDerived.cs b/src/runtime/Types/ClassDerived.cs
@@ -144,6 +144,7 @@ internal static NewReference ToPython(IPythonDerivedType obj)
         /// </summary>
         internal static Type CreateDerivedType(string name,
             Type baseType,
+            IEnumerable<Type> interfaces2,
             BorrowedReference py_dict,
             string? namespaceStr,
             string? assemblyName,
@@ -163,8 +164,8 @@ internal static Type CreateDerivedType(string name,
             ModuleBuilder moduleBuilder = GetModuleBuilder(assemblyName, moduleName);
 
             Type baseClass = baseType;
-            var interfaces = new List<Type> { typeof(IPythonDerivedType) };
-
+            var interfaces = new HashSet<Type> { typeof(IPythonDerivedType) };
+            foreach(var t in interfaces2) interfaces.Add(t);
             // 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)
@@ -215,7 +216,7 @@ internal static Type CreateDerivedType(string name,
             }
 
             // override any virtual methods not already overridden by the properties above
-            MethodInfo[] methods = baseType.GetMethods();
+            var methods = baseType.GetMethods().Concat(interfaces.SelectMany(x => x.GetMethods()));
             var virtualMethods = new HashSet<string>();
             foreach (MethodInfo method in methods)
             {

diff --git a/src/runtime/Types/MetaType.cs b/src/runtime/Types/MetaType.cs
@@ -1,5 +1,8 @@
 using System;
+using System.Collections.Generic;
 using System.Diagnostics;
+using System.Linq;
+using System.Reflection;
 using System.Runtime.InteropServices;
 using System.Runtime.Serialization;
 
@@ -84,36 +87,58 @@ public static NewReference tp_new(BorrowedReference tp, BorrowedReference args,
             // That type must itself have a managed implementation. We check
             // that by making sure its metatype is the CLR metatype.
 
-            if (Runtime.PyTuple_Size(bases) != 1)
+
+            List<Type> interfaces = new List<Type>();
+            List<ClassBase> baseType = new List<ClassBase>();
+
+            var cnt = Runtime.PyTuple_GetSize(bases);
+
+            for (uint i = 0; i < cnt; i++)
+            {
+                var base_type2 = Runtime.PyTuple_GetItem(bases, (int)i);
+                var cb2 = (ClassBase) GetManagedObject(base_type2);
+                if (cb2 != null)
+                {
+                    if (cb2.type.Valid && cb2.type.Value.IsInterface)
+                        interfaces.Add(cb2.type.Value);
+                    else baseType.Add(cb2);
+                }
+            }
+
+            if (baseType.Count == 0)
+            {
+                baseType.Add(new ClassBase(typeof(object)));
+            }
+
+
+            if (baseType.Count > 1)
             {
                 return Exceptions.RaiseTypeError("cannot use multiple inheritance with managed classes");
             }
 
-            BorrowedReference base_type = Runtime.PyTuple_GetItem(bases, 0);
-            BorrowedReference mt = Runtime.PyObject_TYPE(base_type);
+            /*
+            BorrowedReference mt = Runtime.PyObject_TYPE(baseType);
 
             if (!(mt == PyCLRMetaType || mt == Runtime.PyTypeType))
             {
                 return Exceptions.RaiseTypeError("invalid metatype");
-            }
+            }*/
 
             // Ensure that the reflected type is appropriate for subclassing,
             // disallowing subclassing of delegates, enums and array types.
 
-            if (GetManagedObject(base_type) is ClassBase cb)
+            var cb = baseType.First();
+            try
             {
-                try
+                if (!cb.CanSubclass())
                 {
-                    if (!cb.CanSubclass())
-                    {
-                        return Exceptions.RaiseTypeError("delegates, enums and array types cannot be subclassed");
-                    }
-                }
-                catch (SerializationException)
-                {
-                    return Exceptions.RaiseTypeError($"Underlying C# Base class {cb.type} has been deleted");
+                    return Exceptions.RaiseTypeError("delegates, enums and array types cannot be subclassed");
                 }
             }
+            catch (SerializationException)
+            {
+                return Exceptions.RaiseTypeError($"Underlying C# Base class {cb.type} has been deleted");
+            }
 
             BorrowedReference slots = Runtime.PyDict_GetItem(dict, PyIdentifier.__slots__);
             if (slots != null)
@@ -127,21 +152,25 @@ public static NewReference tp_new(BorrowedReference tp, BorrowedReference args,
             // into python.
             if (null != dict)
             {
+                var btt = baseType.FirstOrDefault().type.ValueOrNull;
+                var ctor = btt?.GetConstructors(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic)
+                    .FirstOrDefault(x => x.GetParameters().Any() == false);
                 using var clsDict = new PyDict(dict);
 
                 if (clsDict.HasKey("__assembly__") || clsDict.HasKey("__namespace__")
-                                                   || (cb.type.Valid && cb.type.Value != null && cb.type.Value.GetConstructor(Array.Empty<Type>()) != null))
+                                                   || (ctor != null))
                 {
                     if (!clsDict.HasKey("__namespace__"))
                     {
                         clsDict["__namespace__"] =
                             (clsDict["__module__"].ToString()).ToPython();
                     }
-                    return TypeManager.CreateSubType(name, base_type, clsDict);
+                    return TypeManager.CreateSubType(name, baseType, interfaces, clsDict);
                 }
 
             }
 
+            var base_type = Runtime.PyTuple_GetItem(bases, 0);
             // otherwise just create a basic type without reflecting back into the managed side.
             IntPtr func = Util.ReadIntPtr(Runtime.PyTypeType, TypeOffset.tp_new);
             NewReference type = NativeCall.Call_3(func, tp, args, kw);

diff --git a/src/runtime/Types/ReflectedClrType.cs b/src/runtime/Types/ReflectedClrType.cs
@@ -68,14 +68,15 @@ internal void Restore(ClassBase cb)
         TypeManager.InitializeClass(this, cb, cb.type.Value);
     }
 
-    internal static NewReference CreateSubclass(ClassBase baseClass,
+    internal static NewReference CreateSubclass(ClassBase baseClass, IEnumerable<Type> interfaces,
                                                 string name, string? assembly, string? ns,
                                                 BorrowedReference dict)
     {
         try
         {
             Type subType = ClassDerivedObject.CreateDerivedType(name,
                 baseClass.type.Value,
+                interfaces,
                 dict,
                 ns,
                 assembly);

diff --git a/src/testing/generictest.cs b/src/testing/generictest.cs
@@ -95,6 +95,11 @@ public string Overloaded<Q>(int arg1, int arg2, string arg3)
         {
             return arg3;
         }
+
+        public virtual Q VirtualOverloaded<Q>(Q arg)
+        {
+            return arg;
+        }
     }
 
     public class GenericStaticMethodTest<T>
@@ -118,10 +123,7 @@ public static Q Overloaded<Q>(Q arg)
             return arg;
         }
 
-        public static U Overloaded<Q, U>(Q arg1, U arg2)
-        {
-            return arg2;
-        }
+
 
         public static string Overloaded<Q>(int arg1, int arg2, string arg3)
         {

diff --git a/src/testing/subclasstest.cs b/src/testing/subclasstest.cs
@@ -124,4 +124,25 @@ public static int test_event(IInterfaceTest x, int value)
             return et.value;
         }
     }
+
+    public interface ISimpleInterface
+    {
+        bool Ok();
+    }
+
+    public class SimpleClass
+    {
+
+        public static void TestObject(object obj)
+        {
+            if (obj is ISimpleInterface)
+            {
+
+            }
+            else
+            {
+                throw new Exception();
+            }
+        }
+    }
 }
diff --git a/tests/test_subclass.py b/tests/test_subclass.py
@@ -9,7 +9,7 @@
 import System
 import pytest
 from Python.Test import (IInterfaceTest, SubClassTest, EventArgsTest,
-                         FunctionsTest, GenericVirtualMethodTest)
+                         FunctionsTest, GenericVirtualMethodTest, ISimpleInterface, SimpleClass)
 from System.Collections.Generic import List
 
 
@@ -272,6 +272,28 @@ class OverloadingSubclass2(OverloadingSubclass):
     obj = OverloadingSubclass()
     assert obj.VirtMethod[int](5) == 5
 
+def test_interface_and_class_impl():
+    class OverloadingSubclass(GenericVirtualMethodTest):
+        __namespace__ = "test_virtual_generic_method_cls"
+    class OverloadingSubclass2(OverloadingSubclass):
+        pass
+    obj = OverloadingSubclass()
+    assert obj.VirtMethod[int](5) == 5
+
+def test_interface_and_class_impl2():
+    class DualSubClass(ISimpleInterface, SimpleClass):
+        def Ok(self):
+            return True
+    class DualSubClass2(ISimpleInterface):
+        def Ok(self):
+            return True
+
+    obj = DualSubClass()
+    SimpleClass.TestObject(obj)
+    obj = DualSubClass2()
+    SimpleClass.TestObject(obj)
+
+
 def test_construction_from_clr():
     import clr
     calls = []