[S] Change in flashrom[master]: [WIP] test_build.sh: Rework programmer selection using Meson

[Felix Singer (Code Review)]

Attention is currently required from: Nico Huber, Angel Pons.

Felix Singer has posted comments on this change. ( https://review.coreboot.org/c/flashrom/+/68068 )

Change subject: [WIP] test_build.sh: Rework programmer selection using Meson
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Patch Set 3:

(1 comment)

Patchset:

PS3:
> Is that file not in a standard format? I wouldn't know, is it python?

No, it's not Python. The Meson syntax is just similar to it in some ways. See https://mesonbuild.com/Syntax.html
> Maybe the problem is that we are trying to write a build system on top of build systems.

Yeah, I think the same. Inventing a parser seems too much.
> The repeated builds are easy enough to write in make, how is it in meson? If it's not possible, maybe that's something we should teach it?

As far as I know, the Meson tool only has a pre-defined set of commands and they don't allow just printing the possible values for an option. `meson configure <builddir>` gives an overview about options and values, but that's not parseable at all.

However, I might have found a nice solution. Meson allows you to spawn a temporary shell environment, called dev environment, which has additional shell variables for debugging for example.

So, I have created CB:68248 which creates such a dev environment in the top-level meosn.build and the list of programmers is added to `FLASHROM_ALL_PROGRAMMERS`, a shell variable. The dev environment can be entered with `meson devenv -C <build_dir>` but you also can execute commands directly if you add them at the end, which is what I have done to read the content of `FLASHROM_ALL_PROGRAMMERS`.

I think this is the best and easiest solution which we can get. I would keep the discussion here so that it is not scattered.