A new attempt on PyKDE5 binding generation

[Shaheed Haque]

Hi all,

I've given up on trying to get the twine2 PyKDE bindings generator
working [1] because not only is the code there broken, but it seems a
Sysiphusian task to maintain a C++ parser. Instead, a few evenings
with clang 3.9 have yielded what I hope is the basis of a way forward:
about 800 lines of Python code [2] which can already create 684 .sip
files [3].

What I hope is important about the new tool is that it is documented,
and has a rule-driven approach to adding the SIP annotations which
should ensure that the bindings are easier to maintain once we
actually get them working.

The current status is:

    #1 I have not tried to actually run the SIP compiler :-).

    #2 I have not checked whether the tool is failing to process some
.h files (i.e. I have not checked whether I have all the relevant .h
headers, or whether the new tool is failing on some .h files).

    #3 I have toyed with, but not mounted a full attack on, the SIP
annotations problem (see below)

    #4 I have not tried to map the KDE5 module naming scheme to
anything in Python.

    #5 No integration with CMake and the rest of the KDE build system.

On the annotations problem, looking at PyKDE4 as my guide, I frankly
don't understand when to use /Transfer/ instead of /TransferThis/, or
why some references parameters have a /In/ and others a /Out/ or
whatever. If anybody can actually explain, that would be great. In any
event, I am hopeful that the structure of the rules engine [4] will
make this tractable, but I'd really prefer not to blindly match what I
see in PyKDE4!!!

Anyway, comments - and help - welcome, especially on #1, #4 and #5 as
I intend to focus on #2 and #3 first.

Thanks, Shaheed

[1] https://quickgit.kde.org/?p=twine2.git

[2] https://quickgit.kde.org/?p=pykde5.git&a=log&h=e07351e137e8a3f01c64f6c33feb9938b6fdcdd8

[3] This compares to 942 in PyKDE4, and 171 presently in PyKDE5. The
set of 684 was generated from whatever set of KDE headers I happen to
have installed.

[4] https://quickgit.kde.org/?p=pykde5.git&a=commitdiff&h=e07351e137e8a3f01c64f6c33feb9938b6fdcdd8