Moving Epoxy to Meson

Meson is a new build system, written in Python, that generates Ninja, Visual Studio, and XCode project files. It has appealing factors:

• it's fast
• it does not fork to the shell
• it does not use libtool
• it does not use m4
• it has a small, non-Turing complete language for defining the build
• it uses modern tools to find dependencies
• it can be introspected through a simple JSON format
• it's really fast

Epoxy is a prime candidate for switching to Meson as its primary build system:

• it's small
• it's self-contained
• it has little to no dependencies

Porting to Meson yields fairly good results in terms of complexity:

• Autotools requires 6 files, for a total of 651 lines; it also depends on additional m4 macros from X.org
• Meson requires 4 files, for a total of 512 lines; no additional dependencies are required

On the timing side, Meson is about 45% faster than Autotools at building and running the test suite:

Reference system

• Dell XPS 13 "Kaby Lake"
  • Core i7-7500U (4 cores)
  • NVMe SSD

Meson

Command chain

• mkdir _build && pushd _build
• meson
• ninja
• ninja test
• popd && rm -rf _build

Notes

• Ninja automatically figures out the appropriate number of parallel jobs
• Ninja automatically runs the test suite in parallel

Timing

• real 0m10.119s
• user 0m16.507s
• sys 0m1.666s

Autotools

Command chain

• NOCONFIGURE=1 ./autogen.sh
• mkdir _build && pushd _build
• ../configure
• make -j$(($(nproc) + 2))
• make -j$(($(nproc) + 2)) check
• popd && rm -rf _build

Notes

• Perform a builddir != srcdir build for a comparison with Meson; autogen.sh still dumps files inside the srcdir, which requires a full clean when rebuilding after a change to the build system
• $(($(nproc) + 2)) yields an equivalent number of parallel jobs as Ninja would use

Timing

• real 0m17.823s
• user 0m22.650s
• sys 0m4.271s