fjellstad.org

One of the problems of doing cross-platform development, is that you don’t necessary know what the environment will be at the person who is compiling your software. So, you need to be able to check this and maybe notify the user what additional software needs to be installed. You also want your build system to be flexible enough to maybe work around issues and options.

I used to write the build system for the unix development at my previous work. Since the target was limited to HP-UX and Solaris, it was somewhat easy to just create a script which figured out which platform we were at, and then copy the platform specific Makefile to the right location. When I started working on my own private projects, I wanted to make it more robust. Initially I was looking at the automake/autoconf systems. I found it a little too complicated for my needs, although autoconf by itself might have been useful. I still find it somewhat troubling to have to learn another language (M4) to write the configuration files. To me, configuration files that generate the Makefiles should be as simple as possible.

While I was investigating and trying out build systems, I heard that KDE had started using cmake. This made me at least a little curious about it.

The initial impression was that cmake makes it really easy to get started. I was up and running faster with cmake than I did with the autotools chaintools, and almost as fast as writing my own Makefiles. Now, my projects aren’t as big as the KDE project, but if it works for them, it should work for me.

One of the problem I found is the some problem I have found with most cross-platform tools: it has to target the least common denominator. Some of the features seem to indicate that cmake was first developed on Windows, or that developers were primary Windows developers. For instance, there wasn’t a good way to clean up custom generated files using cmake, as in you could make clean target in Make have a dependency on something else, so that that something else also got removed when clean was called. Reading the faq, this seems to have been fixed in 2.4.

Although I haven’t done anything complicated with cmake yet, so far I have been pretty happy with it. It isn’t much more complicated than handwritten Makefiles, and it should save me tons of work on porting.