Implemented type discovery feature.

The problem:

- There are two class, A and B, B inherits from A.
- You are inside a virtual method reimplemented in python with just one parameter of type A*.
- But the object referenced by a variable of type A* is an instance of B and it was created by C++,
  not Python!
- Shiboken needs to create a PyObject of type B, not A! This does not makes sense for C++, but does
  for Python, because python variables does not store type information, just values.

To achieve this we use RTTI to get the real type name of a variable, then we create the PyObject using
the TypeResolver infrastructure initially developed to help with signal slot problems. In other words,
the TypeResolver class has been moved from libpyside to libshiboken.

6 files changed, 264 insertions, 7 deletions

diff --git a/libshiboken/CMakeLists.txt b/libshiboken/CMakeLists.txt
index f36567d63..3cc0a5618 100644
--- a/libshiboken/CMakeLists.txt
+++ b/libshiboken/CMakeLists.txt
@@ -14,6 +14,7 @@ basewrapper.cpp
 helper.cpp
 pyenum.cpp
 bindingmanager.cpp
+typeresolver.cpp
 )
 
 include_directories(${CMAKE_CURRENT_SOURCE_DIR}
diff --git a/libshiboken/basewrapper.cpp b/libshiboken/basewrapper.cpp
index cad4efe0d..b0f1b9c0a 100644
--- a/libshiboken/basewrapper.cpp
+++ b/libshiboken/basewrapper.cpp
@@ -36,6 +36,7 @@
 #include <cstddef>
 #include <algorithm>
 #include "autodecref.h"
+#include "typeresolver.h"
 
 namespace Shiboken
 {
@@ -109,12 +110,24 @@ void destroyParentInfo(SbkBaseWrapper* obj, bool removeFromParent)
 PyObject* SbkBaseWrapper_New(SbkBaseWrapperType* instanceType,
                              const void* cptr,
                              bool hasOwnership,
-                             bool containsCppWrapper)
+                             bool isExactType)
 {
+    // Try to find the exact type of cptr.
+    if (!isExactType && instanceType->type_name_func) {
+        const char* typeName = instanceType->type_name_func(cptr);
+        TypeResolver* typeResolver = TypeResolver::get(typeName);
+        if (typeResolver)
+            instanceType = reinterpret_cast<SbkBaseWrapperType*>(typeResolver->pythonType());
+        #ifndef NDEBUG
+        else
+            fprintf(stderr, "[SHIBOKEN] Can't find type resolver for %s.\n", typeName);
+        #endif
+    }
+
     SbkBaseWrapper* self = reinterpret_cast<SbkBaseWrapper*>(SbkBaseWrapper_TpNew(reinterpret_cast<PyTypeObject*>(instanceType), 0, 0));
     self->cptr = const_cast<void*>(cptr);
     self->hasOwnership = hasOwnership;
-    self->containsCppWrapper = containsCppWrapper;
+    self->containsCppWrapper = 0;
     self->validCppObject = 1;
     self->parentInfo = 0;
     BindingManager::instance().registerWrapper(self);
@@ -253,7 +266,8 @@ SbkBaseWrapperType SbkBaseWrapper_Type = { { {
 }, },
 /*mi_offsets*/          0,
 /*mi_init*/             0,
-/*mi_specialcast*/      0
+/*mi_specialcast*/      0,
+/*type_name_func*/      0
 };
 
 PyAPI_FUNC(void) init_shiboken()
diff --git a/libshiboken/basewrapper.h b/libshiboken/basewrapper.h
index 7de5f9086..38e0a0c48 100644
--- a/libshiboken/basewrapper.h
+++ b/libshiboken/basewrapper.h
@@ -69,6 +69,7 @@ struct SbkBaseWrapperType;
 *   The implementation of this function is auto generated by the generator and you don't need to care about it.
 */
 typedef void* (*SpecialCastFunction)(PyObject*, SbkBaseWrapperType*);
+typedef const char* (*TypeNameFunction)(const void*);
 
 LIBSHIBOKEN_API PyAPI_DATA(PyTypeObject) SbkBaseWrapperType_Type;
 LIBSHIBOKEN_API PyAPI_DATA(SbkBaseWrapperType) SbkBaseWrapper_Type;
@@ -81,6 +82,7 @@ struct LIBSHIBOKEN_API SbkBaseWrapperType
     MultipleInheritanceInitFunction mi_init;
     /// Special cast function, null if this class doesn't have multiple inheritance.
     SpecialCastFunction mi_specialcast;
+    TypeNameFunction type_name_func;
 };
 
 /// Base Python object for all the wrapped C++ classes.
@@ -194,7 +196,7 @@ LIBSHIBOKEN_API PyAPI_FUNC(PyObject*)
 SbkBaseWrapper_New(SbkBaseWrapperType* instanceType,
                    const void* cptr,
                    bool hasOwnership = true,
-                   bool containsCppWrapper = false);
+                   bool isExactType = false);
 
 LIBSHIBOKEN_API PyAPI_FUNC(PyObject*)
 SbkBaseWrapper_TpNew(PyTypeObject* subtype, PyObject*, PyObject*);
diff --git a/libshiboken/conversions.h b/libshiboken/conversions.h
index 1dc00b00f..e3b2ac34b 100644
--- a/libshiboken/conversions.h
+++ b/libshiboken/conversions.h
@@ -89,10 +89,10 @@ struct CppObjectCopier
  * Convenience template to create wrappers using the proper Python type for a given C++ class instance.
  */
 template<typename T>
-inline PyObject* SbkCreateWrapper(const T* cppobj, bool hasOwnership = false, bool containsCppWrapper = false)
+inline PyObject* SbkCreateWrapper(const T* cppobj, bool hasOwnership = false, bool isExactType = false)
 {
     return SbkBaseWrapper_New(reinterpret_cast<SbkBaseWrapperType*>(SbkType<T>()),
-                              cppobj, hasOwnership, containsCppWrapper);
+                              cppobj, hasOwnership, isExactType);
 }
 
 // Base Conversions ----------------------------------------------------------
@@ -105,7 +105,9 @@ struct ConverterBase
     static inline PyObject* toPython(void* cppobj) { return toPython(*reinterpret_cast<T*>(cppobj)); }
     static inline PyObject* toPython(const T& cppobj)
     {
-        return SbkCreateWrapper<T>(CppObjectCopier<T>::copy(cppobj), true, CppObjectCopier<T>::isCppWrapper);
+        PyObject* obj = SbkCreateWrapper<T>(CppObjectCopier<T>::copy(cppobj), true, true);
+        SbkBaseWrapper_setContainsCppWrapper(obj, CppObjectCopier<T>::isCppWrapper);
+        return obj;
     }
     // Classes with implicit conversions are expected to reimplement
     // this to build T from its various implicit constructors.
diff --git a/libshiboken/typeresolver.cpp b/libshiboken/typeresolver.cpp
new file mode 100644
index 000000000..3ed3daf67
--- /dev/null
+++ b/libshiboken/typeresolver.cpp
@@ -0,0 +1,125 @@
+/*
+ * This file is part of the Shiboken Python Bindings Generator project.
+ *
+ * Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+ *
+ * Contact: PySide team <contact@pyside.org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * version 2.1 as published by the Free Software Foundation. Please
+ * review the following information to ensure the GNU Lesser General
+ * Public License version 2.1 requirements will be met:
+ * http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+ *
+ * As a special exception to the GNU Lesser General Public License
+ * version 2.1, the object code form of a "work that uses the Library"
+ * may incorporate material from a header file that is part of the
+ * Library.  You may distribute such object code under terms of your
+ * choice, provided that the incorporated material (i) does not exceed
+ * more than 5% of the total size of the Library; and (ii) is limited to
+ * numerical parameters, data structure layouts, accessors, macros,
+ * inline functions and templates.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#include "typeresolver.h"
+#include "google/dense_hash_map"
+#include <cstdlib>
+
+using namespace Shiboken;
+
+typedef google::dense_hash_map<std::string, TypeResolver*> TypeResolverMap;
+static TypeResolverMap typeResolverMap;
+
+struct TypeResolver::TypeResolverPrivate
+{
+    const char* typeName; // maybe this is not needed anymore
+    CppToPythonFunc cppToPython;
+    PythonToCppFunc pythonToCpp;
+    DeleteObjectFunc deleteObject;
+    GetPyTypeFunc getPyType;
+};
+
+static void deinitTypeResolver()
+{
+    for (TypeResolverMap::const_iterator it = typeResolverMap.begin(); it != typeResolverMap.end(); ++it)
+        delete it->second;
+    typeResolverMap.clear();
+}
+
+static void registerTypeResolver(TypeResolver* resolver)
+{
+    static bool initied = false;
+    if (!initied) {
+        assert(typeResolverMap.empty());
+        typeResolverMap.set_empty_key("");
+        typeResolverMap.set_deleted_key("?");
+        initied = true;
+        std::atexit(deinitTypeResolver);
+        TypeResolver::createValueTypeResolver<double>("double");
+        TypeResolver::createValueTypeResolver<float>("float");
+        TypeResolver::createValueTypeResolver<bool>("bool");
+        TypeResolver::createValueTypeResolver<int>("int");
+    }
+    assert(typeResolverMap.find(resolver->typeName()) == typeResolverMap.end());
+    typeResolverMap[resolver->typeName()] = resolver;
+}
+
+TypeResolver::TypeResolver(const char* typeName, TypeResolver::CppToPythonFunc cppToPy, TypeResolver::PythonToCppFunc pyToCpp, GetPyTypeFunc getPyType, TypeResolver::DeleteObjectFunc deleter)
+{
+    m_d = new TypeResolverPrivate;
+    m_d->typeName = typeName;
+    m_d->cppToPython = cppToPy;
+    m_d->pythonToCpp = pyToCpp;
+    m_d->deleteObject = deleter;
+    m_d->getPyType = getPyType;
+
+    registerTypeResolver(this);
+}
+
+TypeResolver::~TypeResolver()
+{
+    delete m_d;
+}
+
+TypeResolver* TypeResolver::get(const char* typeName)
+{
+    TypeResolverMap::const_iterator it = typeResolverMap.find(typeName);
+    return it == typeResolverMap.end() ? 0 : it->second;
+}
+
+const char* TypeResolver::typeName() const
+{
+    return m_d->typeName;
+}
+
+void* TypeResolver::toCpp(PyObject* pyObj)
+{
+    return m_d->pythonToCpp(pyObj);
+}
+
+PyObject* TypeResolver::toPython(void* cppObj)
+{
+    return m_d->cppToPython(cppObj);
+}
+
+void TypeResolver::deleteObject(void* object)
+{
+    if (m_d->deleteObject)
+        m_d->deleteObject(object);
+}
+
+PyTypeObject* TypeResolver::pythonType()
+{
+    return m_d->getPyType();
+}
diff --git a/libshiboken/typeresolver.h b/libshiboken/typeresolver.h
new file mode 100644
index 000000000..4e7efb81b
--- /dev/null
+++ b/libshiboken/typeresolver.h
@@ -0,0 +1,113 @@
+/*
+ * This file is part of the Shiboken Python Bindings Generator project.
+ *
+ * Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+ *
+ * Contact: PySide team <contact@pyside.org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * version 2.1 as published by the Free Software Foundation. Please
+ * review the following information to ensure the GNU Lesser General
+ * Public License version 2.1 requirements will be met:
+ * http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+ *
+ * As a special exception to the GNU Lesser General Public License
+ * version 2.1, the object code form of a "work that uses the Library"
+ * may incorporate material from a header file that is part of the
+ * Library.  You may distribute such object code under terms of your
+ * choice, provided that the incorporated material (i) does not exceed
+ * more than 5% of the total size of the Library; and (ii) is limited to
+ * numerical parameters, data structure layouts, accessors, macros,
+ * inline functions and templates.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#ifndef TYPERESOLVER_H
+#define TYPERESOLVER_H
+
+#include "shibokenmacros.h"
+#include "conversions.h"
+
+namespace Shiboken
+{
+
+class SbkBaseWrapperType;
+
+/* To C++ convertion functions. */
+template <typename T>
+inline void* pythonToValueType(PyObject* pyobj)
+{
+    return Shiboken::CppObjectCopier<T>::copy(Shiboken::Converter<T>::toCpp(pyobj));
+}
+
+template <typename T>
+inline void* pythonToObjectType(PyObject* pyobj)
+{
+    return Shiboken::Converter<T*>::toCpp(pyobj);
+}
+
+template <typename T>
+inline void objectDeleter(void* data)
+{
+    delete reinterpret_cast<T*>(data);
+}
+
+template <typename T>
+inline PyObject* objectTypeToPython(void* cptr)
+{
+    return Shiboken::Converter<T*>::toPython(*reinterpret_cast<T**>(cptr));
+}
+
+class LIBSHIBOKEN_API TypeResolver
+{
+public:
+    typedef PyObject* (*CppToPythonFunc)(void*);
+    typedef void* (*PythonToCppFunc)(PyObject*);
+    typedef void (*DeleteObjectFunc)(void*);
+    typedef PyTypeObject* (*GetPyTypeFunc)();
+
+    ~TypeResolver();
+
+    template<typename T>
+    static TypeResolver* createValueTypeResolver(const char* typeName)
+    {
+        return new TypeResolver(typeName, &Shiboken::Converter<T>::toPython, &pythonToValueType<T>, &SbkType<T>, &objectDeleter<T>);
+    }
+
+    template<typename T>
+    static TypeResolver* createObjectTypeResolver(const char* typeName)
+    {
+        return new TypeResolver(typeName, &objectTypeToPython<T>, &pythonToObjectType<T>, &SbkType<T>);
+    }
+
+    static TypeResolver* get(const char* typeName);
+
+    const char* typeName() const;
+    PyObject* toPython(void* cppObj);
+    void* toCpp(PyObject* pyObj);
+    void deleteObject(void* object);
+    PyTypeObject* pythonType();
+
+private:
+    struct TypeResolverPrivate;
+    TypeResolverPrivate* m_d;
+
+    // disable object copy
+    TypeResolver(const TypeResolver&);
+    TypeResolver& operator=(const TypeResolver&);
+
+    TypeResolver(const char* typeName, CppToPythonFunc cppToPy, PythonToCppFunc pyToCpp, GetPyTypeFunc getPyType, DeleteObjectFunc deleter = 0);
+};
+}
+
+#endif