add meson build system support

[pobrn]

I would like to propose adding meson build system support to isolate. Many projects use it, it has a python-like syntax, and in my opinion much easier to grasp than makefiles. It also has a lot of convenience functions related to dependency lookups, etc.

Thoughts? This is not entirely completely, but I have been using this without issues.

[gollux]

I don't think it helps: the meson build does not look easier to use/maintain than the rather simple Makefile we have.

I also appreciate that the current Makefile makes it clear with what flags we run gcc.

In general, I don't think we should maintain configuration for two build systems as it's an unnecessary burden to keep them synchronized. I don't object to switching to another build system altogether, but only if it brings some benefits.

[pobrn]

I don't think it helps: the meson build does not look easier to use/maintain than the rather simple Makefile we have.

That's definitely subjective, yes. I would personally take a meson build file almost every day over a Makefile.

I also appreciate that the current Makefile makes it clear with what flags we run gcc.

Running ninja -C build -v or meson compile -C build --ninja-args=-v lists all commands. But admittedly you have to make more effort.

I don't object to switching to another build system altogether, but only if it brings some benefits.

The motivation was that the current Makefile does not install the systemd files. So I took that opportunity to try meson. In any case, that is missing from the Makefile.

I feel that meson provides a more "familiar" interface, while every makefile tends to have its quirks and differences. For example, it provides a buildtype option to set debug/release/etc. build types; it also makes it easy to use sanitizers. And should tests ever be added, they can also be integrated easily. What I like apart from the more uniform interface is that it generates "compile_commands.json", which works nicely with clangd, clang-tidy, etc.

Naturally I understand this ultimately comes down to personal preference, so I am awaiting your questions or decision.

[gollux]

I know that I can ask meson to list the commands. But it lists them for the current machine, while I want to understand what is used in general.

I prefer to keep using make for the time being.

[pobrn]

Okay, I will keep this working for the foreseeable future, but feel free to close the PR.