Roadmap 2021

[Tomasz Gajewski]

Norman Feske <norman.feske at genode-labs.com> writes:

> Even though there was a brief period of activity when Stefan made some
> progress, the topic [1] became stale again. I understand the slip of
> motivation. Even though I have enabled the Rpi (including working USB)
> originally, I would not consider picking it up again in my spare time.
> I'm sorry that the support from our side was insufficient for you to
> carry on. Unfortunately, I doubt that 2021 will look much different.
>
> [1] https://github.com/genodelabs/genode/issues/3247

I know the situation. And issue number looks familiar to me :-)

>> During this process once again I realized why I don't like build
>> system based on make and especially after I found out that recursive
>> make in case of Genode build system can be written with capitalized
>> "R" in recursive :-).
>
> Please let me address the statement regarding "recursive make" in
> Genode.
>
> What is commonly referred to as a unholy practice "recursive make" is
> the use of Makefiles scattered throughout a directory structure where
> the Makefile of the parent directory triggers the Makefiles of the
> child directories. Genode's build system does not do that. The
> instances of make spawned by the build system serves different and
> orthogonal purposes.
>
> - The frontend (Makefile in the build directory) consumes the build
>   configuration and triggers lib-dependency stage, the builds, and the
>   invocation of run scripts.
>
> - The library-dependency stage traverses target description files
>   without building anythin, to construct a library-dependency graph.
>   This could strictly be taken as an example of "recursive make" if
>   we decided to split hairs.
>
> - Orchestration of the library and target builds (executing the
>   library-dependency graph, which happens to be a Makefile).
>
> - Library build, building a single library.
>
> - Target build, building a single target.
>

Thank you for this description (although I already gathered knowledge
about this part). Adding run tool to this picture makes this picture a
little more "recursive" :-). Actually removing recursive interplay
between the run tool and build system is something I'd like to remove
but I don't know how and this will be a topic for discussion later.


> If you add the depot tools to the picture, this story continues
> because the depot tools are, well, based on make and invoke Genode's
> make-based build system.

I assume that it is similar to case with run tool but I'll know when I
get to it.


> Make is a can of worms, no question. Please excuse my polemics, but
> this argument can go towards all kinds of power tools [2]. ;-)
>
> [2] https://github.com/satwikkansal/wtfpython

I'll definitely read it. It looks very interesting.


> If I understand these points correctly, you are actually not after
> replacing Genode's build system but rather supplementing scons as
> another option? That would side-step the friction I feared, which
> would be pretty cool.

Generally roadmap is not a good place to actually anounce and discuss it
but I was kind of forced to do it here.

Generally I really, really like the consistency of definitions of
libraries and programs in Genode and my idea is to make it even more
strict with scons. After I release some initial version I'll start
discussion about some issues I found. But for a start - were you aware
that current build system forgives errors like in [1] :-)

https://github.com/genodelabs/genode/blob/master/repos/base-linux/src/test/lx_hybrid_errno/target.mk


>> I hope to finish those parts quickly and make it public this year.
>
> I'm looking forward to try it out.

Great.


>> Plans for next year
>>
>> I plan to further develop build system based on scons at least until it
>> fullfills my own whishes about it or until I find some blocker that I
>> won't be able to overcome. As originally I plan to use it for
>> development for rpi. I know that I'll have to add some support for ports
>> (I plan only wrapper for current descriptions), depots and possibly
>> something more.
>
> I wonder, have you considered adding scons support to the Goa tool [3]?
> Goa is completely independent from Genode's build system and already
> supports make, cmake, autoconf, and qmake.
>
> [3] https://github.com/nfeske/goa

I did not look at this tool yet. Using it to port something is in my
personal work queue and maybe then some extension ideas will come.


Cheers
Tomasz