Autotools Mythbuster: being a foreigner is not a bad thing

This was a leftover post on my drafts’ list.. I just decided to post it as it is, even though there are a few things that are slightly out of date. Please bear with me.

Have you ever noticed that many projects ship in their tarball or, even worse, in their source repositories, files that are either empty or simply placeholder saying “look at this other file”? Most of the time these files are NEWS, ChangeLog, COPYING and INSTALL. In some corner cases, I even found packages that have files called INSTALL.real.

So what’s going on with this? Well, the problem comes from automake, and its ties to the GNU project it belongs to. The idea behind it is that the default settings of automake have to fit with the GNU projects. And GNU projects have a long list of coding styles, best practices, and policies that might sound silly (and some are) but are consistently followed by official projects.

These policies not only mandate the presence of a stable set of files (including those noted above, and a couple more), but also that the portability warnings are enabled, as the resulting Makefiles are supposed to be usable with non-GNU make implementations. So basically by default automake will mandate the presence of those files, the activation of some warnings’ classes, and that’s the reason why people do create those files even if they are not going to be used (either they are left zero sized or, worse, they get a single line referring to another file — I say worse because for zero sized files we can stop from installing them with simple checks, but for single-line references we require human intervention).

So how do you fix this? Well, it’s actually easy, you just have to pass the foreign option to the AM_INIT_AUTOMAKE macro — this way you’re telling automake that your project does not have to follow the GNU rules, which means that the files no longer have to be there and that if you want portability warnings you have to enable them explicitly. Which is very likely what you want.

Do note that the fact that the files are no longer mandatory does not mean that you can no longer use them. You’re actually suggested to keep most of them in your project, and actually install it properly. But trust me, you want to be a foreigner, in GNU land.

For details on AM_INIT_AUTOMAKE and the various automake flavours, you can see my guide which I also have to expand a little bit over the weekend.

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