Re: [Qemu-devel] converting build system to Meson?

[Markus Armbruster <armbru@redhat.com>]

Paolo Bonzini <pbonzini@redhat.com> writes:

> Hi all,
>
> lately I have been thinking of converting the QEMU build system to
> Meson.  Meson is a relatively new build system that can replace
> Autotools or hand-written Makefiles such as QEMU; as a die-hard
> Autotools fan, I must say that Meson is by far better than anything else
> that has ever tried to replace Autotools, and actually has the potential
> to do so.
>
> Advantages of Meson that directly matter for QEMU include:
>
> - build definitions in a very readable and user friendly DSL, which
> supports looping and conditions.
>
> - ability to introspect the build definitions so that you can find out
> what is built without building it (the DSL is not Turing complete and
> most objects in it are immutable, so it cannot be abused that much :))
>
> - support for a non-recursive build from per-subdirectory input (similar
> to Makefile.objs)

Could Meson build the $(TARGET_DIRS) non-recursively?

I'm asking because I find the make recursion there annoying.  As usual
with recursion, we have to dumb down dependencies: if anything made by
the recursion needs X, then everything does.  If making X fails, we
don't recurse.  Defeats -k.

> - ease of distributing a full copy of Meson to support distros that ship
> an older version (no dependencies apart from Python 3.5).  At 40000
> lines of Python, Meson is relatively small.

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