New porting helper: convert-to-cmake-automoc.pl

Disclaimer

First time I wrote more than a one-liner in Perl, the Swiss Army chainsaw of scripting languages. After quickly skimming the beginner's tutorial, (and no longer just copying Perl one-liners from Stackoverflow and friends), I consider myself ready to write porting helpers for kde-dev-scripts.git! Hey!

If you still don't know those scripts, check them out now. They're tremendously helpful, especially those for porting KDE4-based applications to Qt5/KF5. I wouldn't want to miss them!

Make the most out of CMake's Automoc

Now there's a new porting helper: convert-to-cmake-automoc.pl, just committed today with https://git.reviewboard.kde.org/r/121991/.

This script tries to remove includes such as #include "<basename>.moc" from cpp files to make source code suitable for CMake's Automoc feature.

There are some pitfalls, though:

  • In some cases, one still needs to #include "<basename>.moc"; for example when the moc-generated code uses classes declared inside the .cpp file (hint: K_PLUGIN_FACTORY) -- in this case the moc file cannot be compiled in a separate translation unit.

  • In some cases, one still needs to #include "moc_<basename>.cpp"; for example when Q_PRIVATE_SLOT is used in the header file

This script handles these cases.

Example: attica.git

Invoking this script on your source code will fix the annoying "No output generated" warnings from moc:

$ make
...
/home/kfunk/devel/src/kf5/frameworks/attica/tests/projecttest/projecttest.cpp:0: Note: No relevant classes found. No output generated.
...

Now run find -iname "*.cpp" | xargs convert-to-cmake-automoc.pl and you'll end up with this patch.