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.

1 files changed, 125 insertions, 0 deletions

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();
+}