docs/meson.html

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  10 <div class="header">
  11   <h1>The Mesa 3D Graphics Library</h1>
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  16
  17 <h1>Compilation and Installation using Meson</h1>
  18
  19 <h2 id="basic">1. Basic Usage</h2>
  20
  21 <p><strong>The Meson build system is generally considered stable and ready
  22 for production</strong></p>
  23
  24 <p>The meson build is tested on Linux, macOS, Cygwin and Haiku, FreeBSD,
  25 DragonflyBSD, NetBSD, and should work on OpenBSD.</p>
  26
  27 <p><strong>Mesa requires Meson >= 0.45.0 to build.</strong>
  28
  29 Some older versions of meson do not check that they are too old and will error
  30 out in odd ways.
  31 </p>
  32
  33 <p>
  34 The meson program is used to configure the source directory and generates
  35 either a ninja build file or Visual Studio® build files. The latter must
  36 be enabled via the <code>--backend</code> switch, as ninja is the default backend on all
  37 operating systems. Meson only supports out-of-tree builds, and must be passed a
  38 directory to put built and generated sources into. We'll call that directory
  39 "build" for examples.
  40 </p>
  41
  42 <pre>
  43     meson build/
  44 </pre>
  45
  46 <p>
  47 To see a description of your options you can run <code>meson configure</code>
  48 along with a build directory to view the selected options for. This will show
  49 your meson global arguments and project arguments, along with their defaults
  50 and your local settings.
  51
  52 Meson does not currently support listing options before configure a build
  53 directory, but this feature is being discussed upstream.
  54 </p>
  55
  56 <pre>
  57     meson configure build/
  58 </pre>
  59
  60 <p>
  61 With additional arguments <code>meson configure</code> is used to change
  62 options on already configured build directory. All options passed to this
  63 command are in the form <code>-D "command"="value"</code>.
  64 </p>
  65
  66 <pre>
  67     meson configure build/ -Dprefix=/tmp/install -Dglx=true
  68 </pre>
  69
  70 <p>
  71 Note that options taking lists (such as <code>platforms</code>) are
  72 <a href="http://mesonbuild.com/Build-options.html#using-build-options">a bit
  73 more complicated</a>, but the simplest form compatible with Mesa options
  74 is to use a comma to separate values (<code>-D platforms=drm,wayland</code>)
  75 and brackets to represent an empty list (<code>-D platforms=[]</code>).
  76 </p>
  77
  78 <p>
  79 Once you've run the initial <code>meson</code> command successfully you can use
  80 your configured backend to build the project. With ninja, the -C option can be
  81 be used to point at a directory to build.
  82 </p>
  83
  84 <pre>
  85     ninja -C build/
  86 </pre>
  87
  88 <p>
  89 Without arguments, it will produce libGL.so and/or several other libraries
  90 depending on the options you have chosen. Later, if you want to rebuild for a
  91 different configuration, you should run <code>ninja clean</code> before
  92 changing the configuration, or create a new out of tree build directory for
  93 each configuration you want to build
  94 <a href="http://mesonbuild.com/Using-multiple-build-directories.html">as
  95 recommended in the documentation</a>
  96 </p>
  97
  98 <dl>
  99 <dt><code>Environment Variables</code></dt>
 100 <dd><p>Meson supports the standard CC and CXX environment variables for
 101 changing the default compiler, and CFLAGS, CXXFLAGS, and LDFLAGS for setting
 102 options to the compiler and linker during the initial configuration.
 103
 104 These arguments are consumed and stored by meson when it is initialized. To
 105 change these flags after the build is initialized (or when doing a first
 106 initialization), consider using <code>-D${lang}_args</code> and
 107 <code>-D${lang}_link_args</code> instead. Meson will never change compiler in a
 108 configured build directory.
 109 </p>
 110
 111 <pre>
 112     CC=clang CXX=clang++ meson build-clang
 113     ninja -C build-clang
 114     ninja -C build-clang clean
 115     meson configure build -Dc_args="-Wno-typedef-redefinition"
 116     ninja -C build-clang
 117 </pre>
 118
 119 <p>
 120 The default compilers depends on your operating system. Meson supports most of
 121 the popular compilers, a complete list is available
 122 <a href="http://mesonbuild.com/Reference-tables.html#compiler-ids">here</a>.
 123 </p>
 124
 125 <p>Meson also honors <code>DESTDIR</code> for installs</p>
 126 </dd>
 127
 128
 129 <dt><code>LLVM</code></dt>
 130 <dd><p>Meson includes upstream logic to wrap llvm-config using it's standard
 131 dependency interface. It will search <code>$PATH</code> (or <code>%PATH%</code> on windows) for
 132 llvm-config, so using an LLVM from a non-standard path is as easy as
 133 <code>PATH=/path/with/llvm-config:$PATH meson build</code>.
 134 </p></dd>
 135 </dl>
 136
 137 <dl>
 138 <dt><code>PKG_CONFIG_PATH</code></dt>
 139 <dd><p>The
 140 <code>pkg-config</code> utility is a hard requirement for configuring and
 141 building Mesa on Unix-like systems. It is used to search for external libraries
 142 on the system. This environment variable is used to control the search path for
 143 <code>pkg-config</code>. For instance, setting
 144 <code>PKG_CONFIG_PATH=/usr/X11R6/lib/pkgconfig</code> will search for package
 145 metadata in <code>/usr/X11R6</code> before the standard directories.</p>
 146 </dd>
 147 </dl>
 148
 149 <p>
 150 One of the oddities of meson is that some options are different when passed to
 151 the <code>meson</code> than to <code>meson configure</code>. These options are
 152 passed as --option=foo to <code>meson</code>, but -Doption=foo to <code>meson
 153 configure</code>. Mesa defined options are always passed as -Doption=foo.
 154 </p>
 155
 156 <p>For those coming from autotools be aware of the following:</p>
 157
 158 <dl>
 159 <dt><code>--buildtype/-Dbuildtype</code></dt>
 160 <dd><p>This option will set the compiler debug/optimisation levels to aid
 161 debugging the Mesa libraries.</p>
 162
 163 <p>Note that in meson this defaults to <code>debugoptimized</code>, and
 164 not setting it to <code>release</code> will yield non-optimal
 165 performance and binary size. Not using <code>debug</code> may interfere
 166 with debugging as some code and validation will be optimized away.
 167 </p>
 168
 169 <p> For those wishing to pass their own optimization flags, use the <code>plain</code>
 170 buildtype, which causes meson to inject no additional compiler arguments, only
 171 those in the C/CXXFLAGS and those that mesa itself defines.</p>
 172 </dd>
 173 </dl>
 174
 175 <dl>
 176 <dt><code>-Db_ndebug</code></dt>
 177 <dd><p>This option controls assertions in meson projects. When set to <code>false</code>
 178 (the default) assertions are enabled, when set to true they are disabled. This
 179 is unrelated to the <code>buildtype</code>; setting the latter to
 180 <code>release</code> will not turn off assertions.
 181 </p>
 182 </dd>
 183 </dl>
 184
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