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. +
+ ++ meson build/ ++ +
+To see a description of your options you can run meson configure
+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.
+
+http://mesonbuild.com/Using-multiple-build-directories.html
+
Environment VariablesMeson 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
+LLVMMeson 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_PATHThe
+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
+path for pkg-config. For instance, setting
+PKG_CONFIG_PATH=/usr/X11R6/lib/pkgconfig will search for
+package metadata in /usr/X11R6 before the standard
+directories.
+One of the oddities of meson is that some options are different when passed to
+the meson than to meson configure. These options are
+passed as --option=foo to meson, but -Doption=foo to meson
+configure. Mesa defined options are always passed as -Doption=foo.
+
+ +
For those coming from autotools be aware of the following:
+ +-
+
--buildtype/-Dbuildtype
+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.
+
+
-
+
-Db_ndebug
+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. +
+