Poll on Meson build

[mikkelfj]

Is there any interest in support for the Meson build system?
If so, please write a comment explaining how / why, or why not.

Meson makes it possible to have dependencies on schema files and cause code to recompile partially and properly when changing a schema.

It requires Ninja and Python 3.4. Python is not exposed in build scripts and Meson has no dependencies on other Python libraries.

Meson install on Ubuntu:

apt-get update
apt-get install python3-pip
pip3 install meson

MacOS:

brew update
brew install meson

build:

git clone myproject
cd myproject
mkdir build
meson . build

I already ported it to flatcc 0.4.3 with the exception of a proper AppVeyor build for Windows CI (anyone up for fixing this?)

https://github.com/dvidelabs/flatcc/tree/meson

This branch is not maintained but could be integrated into the main project with sufficient interest.

A demo project using Meson to build a custom project, including a setup script to install Meson is found here: https://github.com/dvidelabs/flatcc-meson-sample

CMake likely would have to be supported as well, or are there no strong feelings about this?

[mikkelfj]

The current CMake / Ninja build does not always rebuild test cases when using ninja -C build/debug <target>, and there are tests disabled because dependencies are broken when using Ninja build with CMake.

Meson has a lot of work going on with cross compilation and ARM target support.

However, Meson still needs some work before maturing for automated CI builds such as building 32-bit binaries on 64-bit MSVC2015 systems, and generally detecting the MSVC compiler environment.

mesonbuild/meson#2134

[mikkelfj]

For anyone following along - there is now a functional Appveyor build for Windows that can build both meson and cmake.

Meson 0.44.0 was the last release supporting python 3.4 which is as high as travis CI goes. Current Meson 0.45.1 required python3.5. This Python jump is a bit of a concern - resulting in the same issues as CMake has with need to run old versions, and one reason this project probably won't switch. However, there is a meson branch that is occasionally updated, at least for now.

The main problem with CMake is that dependencies are broken and especially so with the Ninja backend which is the only way to have fast builds. Due to the code generating nature of flatcc, this is a real problem - the benchmarks can't build with CMake using Ninja. Meson has no issues dealing with this correctly.

However, the primary concern is to build flatcc and libflatccrt.a and the dependency issue is more relevant to tests and derived projects.

[mikkelfj]

v0.5.2-meson has been tagged and meson branch supports flatcc version 0.5.2.

[barcharcraz]

This is relevant to my interests. Being able to just add flatcc as a subproject is great.

[mikkelfj]

Thanks for the feedback.

Does the meson branch work for you as it is?
https://github.com/dvidelabs/flatcc/tree/v0.5.2-meson

[kragniz]

I'm using meson with wrap-git and v0.5.2-meson. It seems to work well so far! It'd be great to have it merged into master.

[mikkelfj]

Thanks. I would probably want Appveyor to build meson on Linux in place of Travis before merging to master. Contributions are welcome.

[kragniz]

What's the reason for Appveyor over some other CI service? I can't say I've had great experiences with it in the past.

[mikkelfj]

In the past Appveyor was very slow and it's only saving grace was that it supported Windows. Later they significantly upgraded their build performance and added improved build matrix support. Later again they added support for Linux builds, but I have not tested that.

Meanwhile Travis started to get slower and randomly started to not support some gcc versions and generally only support fairly old OS. In particular I wasted 1-2 days trying to get Travis to support a recent but not bleeding edge version of Python needed by Meson. Additionally, I frequently have users reporting issues with recent gcc versions that also cannot be supported on Travis.

And finally, having only one CI framework would be an improvement. Since Travis does not support Windows and flatcc does, Travis cannot be that CI solution.

[mikkelfj]

I do have issues with Appveyor not mixing the latest MSVC version with older versions - I somehow have to choose. I worry this will be more difficult when also trying to support Linux builds. This is why I could use some help setting this up. It is rather time consuming.

[kragniz]

I've recently been using builds.sr.ht, which gives access to up to date linux distro images. Maybe using that might be better suited?

[mikkelfj]

Currently they do not support Windows and appears to be in the early stages, and Travis works well enough to not warrant an immediate migration without additional benefits such as also supporting Windows. Meson Travis builds work by using an older Meson version and accepting those limitations, for now.

[ddevault]

Hi, sr.ht guy here. builds.sr.ht doesn't support Windows, but we do support lots of other useful things, like *BSD and multi-arch builds. builds.sr.ht is also quite a lot faster than Travis, almost all builds start within 10 seconds of submission.