In a comparison with current autotools build system, meson/ninja
provides a huge improvement in build speed, while keeping the same
functionalities currently available and being considered more user
friendly.
The new system coexists within the same repository with the current one,
so we can do more extensive testing of its functionality before deciding
if the old system can be removed, or for some reason, has to stay for
good.
- Meson: https://mesonbuild.com
This is the equivalent of autogen/configure step in autotools. It
generates the files that will be used by ninja to actually build the
source code.
The project has received lots of traction recently, with many GNOME
projects willing to move to this new build system. The following wiki
page has more details of the status of the many projects being ported:
https://wiki.gnome.org/Initiatives/GnomeGoals/MesonPorting
Meson has a python-like syntax, easy to read, and the documentation
on the project is very complete, with a dedicated page on how to port
from autotools, explaining how most common use cases can be
implemented using meson.
http://mesonbuild.com/Porting-from-autotools.html
Other important sources of information:
http://mesonbuild.com/howtox.htmlhttp://mesonbuild.com/Syntax.htmlhttp://mesonbuild.com/Reference-manual.html
- Ninja: https://ninja-build.org
Ninja is the equivalent of make in an autotools setup, which actually
builds the source code. It has being used by large and complex
projects such as Google Chrome, Android and LLVM. There is not much to
say about ninja (other than it is much faster than make) because we
won't interact directly with it as much, as meson does the middle man
job here. The reasoning for creating ninja in the first place is
explained on the following post:
http://neugierig.org/software/chromium/notes/2011/02/ninja.html
Also its manual provides more in-depth information about the design
principles:
https://ninja-build.org/manual.html
- Basic workflow:
Meson package is available for most if not all distros, so, taking
Fedora as an example, we only need to run:
# dnf -y install meson ninja-build.
With Meson, building in-tree is not possible at all, so we need to
pass a directory as argument to meson where we want the build to be
done. This has the advantage of creating builds with different options
under the same parent directory, e.g.:
$ meson ./build --prefix=/usr
$ meson ./build-extra -Dextra-checks=true -Dalignment-checks=true
After configuration is done, we call ninja to actually do the build.
$ ninja -C ./build
$ ninja -C ./build install
Ninja defaults to parallel builds, and this can be changed with the -j
flag.
$ ninja -j 10 -C ./build
- Hacking:
* meson.build: Mandatory for the project root and usually found under
each directory you want something to be built.
* meson_options.txt: Options that can interfere with the result of the
build.
Signed-off-by: Eduardo Lima (Etrunko) <etrunko@redhat.com>
Acked-by: Frediano Ziglio <fziglio@redhat.com>
Acked-by: Jonathon Jongsma <jjongsma@redhat.com>
