CMake 3.12 has reached rc1. That means we’re testing the update on FreeBSD, and building lots and lots of packages. And, as I’ve written previously, every CMake update triggers a bunch of interesting software findings.
As a motto, I’ve got “use it, aggressively improve it” on my website (you can hire me for odd CMake and C++ jobs, too). So hitting compile issues makes me turn to fixing software outside of KDE.
- Spring is a 3D RTS engine, with only a minor CMakeLists fix — CMake 3.12 is strict about file(GLOB) and the FOLLOW_SYMLINKS keyword, which is documented only for file(GLOB_RECURSE). Since CMake 3.5, probably much earlier, that keyword has been ignored, and now it’s an error (this is considered a regression).
- Coin3D is a 3D toolkit, which in the version currently available on FreeBSD, doesn’t even use CMake. It hit a bunch of Clang6 compatibility issues, and after some investigation it turns out they had all been fixed already in later releases; I put in a little time to improve FreeBSD compatibility for the next release.
What I found interesting in those two was once again the variety in CMake styles — “Modern CMake Style” still needs to catch on in many places, and the wider ecosystem. Mantis bug-tracker! Mercurial! I remember being a big Mercurial fan years ago when doing KDE-Solaris and complaining how obtuse git is. (It’s still obtuse, but I’m used to it now).
There’s another four dozen ports that have fallout from this update; amusingly Kitware’s VTK 5 and VTK 6 are among them — although a first glance tells me that’s C++ problems and not CMake problems, actually. (Generally, using NULL in places where you want to write 0; older macro definitions of NULL would re-write to something that could successfully be cast to 0, but clang6 in C++17 mode, the default, uses nullptr which doesn’t cast).