Update on PyKF5 bindings

[Boudewijn Rempt]

Okay, I've made some progress. It's not working for me yet, but here's what I did until now:

* because python-clang is only 3.8 on OpenSuse Leap 42.1 and not available on 42.2, I had to build my own llvm: https://phabricator.kde.org/source/krita/browse/rempt%252FT1625-python-scripting/3rdparty/ext_llvm/CMakeLists.txt

* because my setup is python3-only, I made my own llvcm 3.9 tarball with the port to python3 of clang: https://phabricator.kde.org/R37:0ede8c7e56e05bde6f6f4d918301167950819b17

* for the same reason, I "ported" the find-package python scripts to python3: https://phabricator.kde.org/R37:b508ac4a82a199cb2d475b8eaba8518f618bdcbc

* for some weird reason, builting PyQt5 against Qt 5.6.1 doesn't add 5.6.1 to the timeline, so I removed that check from FindPythonModuleGeneration.cmake: https://phabricator.kde.org/R37:8aed64565b566598e0c7d61d5043aecba17ff4d0

* then I even after I added a rules set (the rules set in https://github.com/steveire/kcoreaddons/blob/master/cmake/rules_PyKF5.py is outdated, it has a named includes method that no longer seems to be used?), I still had problems generating sip files from header files that use QObject:

    [ 93%] Generating sip/krita/PyKrita/Action.sip
    _fn_get qt_check_for_QOBJECT_macro
    _fn_get metaObject
    _fn_get qt_metacast
    _fn_get qt_metacall
    _fn_get tr
    Traceback (most recent call last):
      File "/home/boud/dev/deps/share/ECM/find-modules/sip_generator.py", line 688, in main
        body, includes = g.create_sip(args.source, args.include_filename)
      File "/home/boud/dev/deps/share/ECM/find-modules/sip_generator.py", line 127, in create_sip
        body = self._container_get(self.tu.cursor, -1, h_file, include_filename)
      File "/home/boud/dev/deps/share/ECM/find-modules/sip_generator.py", line 202, in _container_get
        decl = self._container_get(member, level + 1, h_file, include_filename)
      File "/home/boud/dev/deps/share/ECM/find-modules/sip_generator.py", line 180, in _container_get
        decl = self._fn_get(container, member, level + 1)
      File "/home/boud/dev/deps/share/ECM/find-modules/sip_generator.py", line 392, in _fn_get
        "init": self._fn_get_parameter_default(function, child),
      File "/home/boud/dev/deps/share/ECM/find-modules/sip_generator.py", line 549, in _fn_get_parameter_default
        return _get_param_value(text, parameterType)
      File "/home/boud/dev/deps/share/ECM/find-modules/sip_generator.py", line 500, in _get_param_value
        if not "::" in parameterType.spelling:
    TypeError: argument of type 'NoneType' is not iterable
    
    plugins/extensions/pykrita/CMakeFiles/generate_PyKrita_sip_files.dir/build.make:88: recipe for target 'plugins/extensions/pykrita/sip/krita/PyKrita/Action.sip' failed
    make[2]: *** [plugins/extensions/pykrita/sip/krita/PyKrita/Action.sip] Error 255

I added a check for None, and now the sip files are being generated: 

@@ -494,6 +495,8 @@ class SipGenerator(object):
             return result
 
         def _get_param_value(text, parameterType):
+            if not parameterType.spelling:
+                return text
             if text == "0":
                 return text
             if not "::" in parameterType.spelling:

* Now the sip files are being generated. I discovered that having Qt/Qtmod.sip in the SIP_DEPENDS gave an error: Qtmod.sip:3: A %CompositeModule cannot be %Imported -- not sure why I added that, but anyways.

* I'm now at the stage where the sip files are generated, and where I probably need to write real rules, because it still doesn't build. I have a number of classes in my C++ wrapper library that are based on classes in other libraries. For instance:

#include <KoCanvasObserverBase.h>

/**
 * DockWidget
 */
class KRITALIBKIS_EXPORT DockWidget : public QDockWidget, public KoCanvasObserverBase
{
};

#endif // LIBKIS_DOCKWIDGET_H

KoCanvasObserverBase is in another library. The old, handwritten sip code looks like this:

%Import QtCore/QtCoremod.sip
%Import QtGui/QtGuimod.sip
%Import QtWidgets/QtWidgetsmod.sip

class DockWidget : public QDockWidget /NoDefaultCtors/
{
%TypeHeaderCode
#include "DockWidget.h"
%End

public:
    explicit DockWidget();
protected:
    virtual void canvasChanged(Canvas *canvas) = 0;

};

And the generated sip code like this:

// Discarded CLASS_DECL on line 28 'KoCanvasBase'
class DockWidget: QDockWidget, KoCanvasObserverBase
{
%TypeHeaderCode
#include <dockwidget.h>
%End
    // Discarded FUNCTION_TEMPLATE on line 35 'qt_check_for_QOBJECT_macro'
    // Discarded VAR_DECL on line 35 'staticMetaObject'
    // Discarded CXX_METHOD on line 35 'metaObject'
    // Discarded CXX_METHOD on line 35 'qt_metacast'
    // Discarded CXX_METHOD on line 35 'qt_metacall'
    // Discarded CXX_METHOD on line 35 'tr'
    // Discarded CXX_METHOD on line 35 'trUtf8'
    DockWidget(const DockWidget & __0);
public:
    DockWidget();
    virtual ~DockWidget();
protected Q_SLOTS:
    virtual void setCanvas(KoCanvasBase*  canvas);
    virtual void unsetCanvas();
protected Q_SLOTS:
    Canvas * canvas() const;
    virtual void canvasChanged(Canvas*  canvas) = 0;
private:
};

This doesn't build, of course:

[ 57%] Generating pybuild/krita/PyKrita/unifiedPyKrita.cpp
sip: KoCanvasObserverBase has not been defined
plugins/extensions/pykrita/CMakeFiles/sip_generated_PyKrita_files.dir/build.make:64: recipe for target 'plugins/extensions/pykrita/pybuild/krita/PyKrita/unifiedPyKrita.cpp' failed
make[2]: *** [plugins/extensions/pykrita/pybuild/krita/PyKrita/unifiedPyKrita.cpp] Error 1
CMakeFiles/Makefile2:25209: recipe for target 'plugins/extensions/pykrita/CMakeFiles/sip_generated_PyKrita_files.dir/all' failed
make[1]: *** [plugins/extensions/pykrita/CMakeFiles/sip_generated_PyKrita_files.dir/all] Error 2
Makefile:127: recipe for target 'all' failed
make: *** [all] Error 2

But I cannot figure out how to use the rules to get the generator to do what I want...

-- 
Boudewijn Rempt | http://www.krita.org, http://www.valdyas.org