Compilation and Installation using Meson
1. Basic Usage
The Meson build system for Mesa is still under active development, and should not be used in production environments.
The meson build is currently only tested on linux, and is known to not work on macOS, Windows, and haiku. This will be fixed.
The meson program is used to configure the source directory and generates either a ninja build file or Visual Studio® build files. The latter must be enabled via the --backend switch, as ninja is the default backend on all operating systems. Meson only supports out-of-tree builds, and must be passed a directory to put built and generated sources into. We'll call that directory "build" for examples.
To see a description of your options you can run
along with a build directory to view the selected options for. This will show
your meson global arguments and project arguments, along with their defaults
and your local settings.
Moes does not currently support listing options before configure a build
directory, but this feature is being discussed upstream.
meson configure build/
With additional arguments
meson configure is used to change
options on already configured build directory. All options passed to this
command are in the form -D "command"="value".
meson configure build/ -Dprefix=/tmp/install -Dglx=true
Once you've run the initial
meson command successfully you can use
your configured backend to build the project. With ninja, the -C option can be
be used to point at a directory to build.
ninja -C build/
Without arguments, it will produce libGL.so and/or several other libraries
depending on the options you have chosen. Later, if you want to rebuild for a
different configuration, you should run
ninja clean before
changing the configuration, or create a new out of tree build directory for
each configuration you want to build.
Meson supports the standard CC and CXX envrionment variables for changing the default compiler, and CFLAGS, CXXFLAGS, and LDFLAGS for setting options to the compiler and linker. The default compilers depends on your operating system. Meson supports most of the popular compilers, a complete list is available here. These arguments are consumed and stored by meson when it is initialized or re-initialized. Therefore passing them to meson configure will not do anything, and passing them to ninja will only do something if ninja decides to re-initialze meson, for example, if a meson.build file has been changed. Changing these variables will not cause all targets to be rebuilt, so running ninja clean is recomended when changing CFLAGS or CXXFLAGS. meson will never change compiler in a configured build directory.
CC=clang CXX=clang++ meson build-clang ninja -C build-clang ninja -C build-clang clean touch meson.build CFLAGS=-Wno-typedef-redefinition ninja -C build-clang
Meson also honors DESTDIR for installs
Meson includes upstream logic to wrap llvm-config using it's standard
dependncy interface. It will search $PATH (or %PATH% on windows) for
llvm-config, so using an LLVM from a non-standard path is as easy as
PATH=/path/with/llvm-config:$PATH meson build.
pkg-config utility is a hard requirement for configuring and
building Mesa on Linux and *BSD. It is used to search for external libraries
on the system. This environment variable is used to control the search
pkg-config. For instance, setting
PKG_CONFIG_PATH=/usr/X11R6/lib/pkgconfig will search for
package metadata in
/usr/X11R6 before the standard
One of the oddities of meson is that some options are different when passed to
meson than to
meson configure. These options are
passed as --option=foo to
meson, but -Doption=foo to
configure. Mesa defined options are always passed as -Doption=foo.
For those coming from autotools be aware of the following:
This option will set the compiler debug/optimisation levels to aid debugging the Mesa libraries.
Note that in meson this defaults to "debugoptimized", and not setting it to "release" will yield non-optimal performance and binary size. Not using "debug" may interfer with debbugging as some code and validation will be optimized away.
For those wishing to pass their own -O option, use the "plain" buildtype, which cuases meson to inject no additional compiler arguments, only those in the C/CXXFLAGS and those that mesa itself defines.
This option controls assertions in meson projects. When set to false (the default) assertions are enabled, when set to true they are disabled. This is unrelated to the
buildtype; setting the latter to
releasewill not turn off assertions.