docs/meson.html

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  10 <div class="header">
  11   <h1>The Mesa 3D Graphics Library</h1>
  12 </div>
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  15 <div class="content">
  16
  17 <h1>Compilation and Installation using Meson</h1>
  18
  19 <ul>
  20   <li><a href="#basic">Basic Usage</a></li>
  21   <li><a href="#cross-compilation">Cross-compilation and 32-bit builds</a></li>
  22 </ul>
  23
  24 <h2 id="basic">1. Basic Usage</h2>
  25
  26 <p><strong>The Meson build system is generally considered stable and ready
  27 for production</strong></p>
  28
  29 <p>The meson build is tested on Linux, macOS, Cygwin and Haiku, FreeBSD,
  30 DragonflyBSD, NetBSD, and should work on OpenBSD.</p>
  31
  32 <p><strong>Mesa requires Meson >= 0.45.0 to build.</strong>
  33
  34 Some older versions of meson do not check that they are too old and will error
  35 out in odd ways.
  36 </p>
  37
  38 <p>
  39 The meson program is used to configure the source directory and generates
  40 either a ninja build file or Visual Studio® build files. The latter must
  41 be enabled via the <code>--backend</code> switch, as ninja is the default backend on all
  42 operating systems. Meson only supports out-of-tree builds, and must be passed a
  43 directory to put built and generated sources into. We'll call that directory
  44 "build" for examples.
  45 </p>
  46
  47 <pre>
  48     meson build/
  49 </pre>
  50
  51 <p>
  52 To see a description of your options you can run <code>meson configure</code>
  53 along with a build directory to view the selected options for. This will show
  54 your meson global arguments and project arguments, along with their defaults
  55 and your local settings.
  56
  57 Meson does not currently support listing options before configure a build
  58 directory, but this feature is being discussed upstream.
  59 </p>
  60
  61 <pre>
  62     meson configure build/
  63 </pre>
  64
  65 <p>
  66 With additional arguments <code>meson configure</code> is used to change
  67 options on already configured build directory. All options passed to this
  68 command are in the form <code>-D "command"="value"</code>.
  69 </p>
  70
  71 <pre>
  72     meson configure build/ -Dprefix=/tmp/install -Dglx=true
  73 </pre>
  74
  75 <p>
  76 Note that options taking lists (such as <code>platforms</code>) are
  77 <a href="http://mesonbuild.com/Build-options.html#using-build-options">a bit
  78 more complicated</a>, but the simplest form compatible with Mesa options
  79 is to use a comma to separate values (<code>-D platforms=drm,wayland</code>)
  80 and brackets to represent an empty list (<code>-D platforms=[]</code>).
  81 </p>
  82
  83 <p>
  84 Once you've run the initial <code>meson</code> command successfully you can use
  85 your configured backend to build the project. With ninja, the -C option can be
  86 be used to point at a directory to build.
  87 </p>
  88
  89 <pre>
  90     ninja -C build/
  91 </pre>
  92
  93 <p>
  94 Without arguments, it will produce libGL.so and/or several other libraries
  95 depending on the options you have chosen. Later, if you want to rebuild for a
  96 different configuration, you should run <code>ninja clean</code> before
  97 changing the configuration, or create a new out of tree build directory for
  98 each configuration you want to build
  99 <a href="http://mesonbuild.com/Using-multiple-build-directories.html">as
 100 recommended in the documentation</a>
 101 </p>
 102
 103 <p>
 104 Autotools automatically updates translation files as part of the build process,
 105 meson does not do this. Instead if you want translated drirc files you will need
 106 to invoke non-default targets for ninja to update them:
 107 <code>ninja -C build/ xmlpool-pot xmlpool-update-po xmlpool-gmo</code>
 108 </p>
 109
 110 <dl>
 111 <dt><code>Environment Variables</code></dt>
 112 <dd><p>Meson supports the standard CC and CXX environment variables for
 113 changing the default compiler. Meson does support CFLAGS, CXXFLAGS, etc. But
 114 their use is discouraged because of the many caveats in using them. Instead it
 115 is recomended to use <code>-D${lang}_args</code> and
 116 <code>-D${lang}_link_args</code> instead. Among the benefits of these options
 117 is that they are guaranteed to persist across rebuilds and reconfigurations.
 118
 119 Meson does not allow changing compiler in a configured builddir, you will need
 120 to create a new build dir for a different compiler.
 121 </p>
 122
 123 <pre>
 124     CC=clang CXX=clang++ meson build-clang
 125     ninja -C build-clang
 126     ninja -C build-clang clean
 127     meson configure build -Dc_args="-Wno-typedef-redefinition"
 128     ninja -C build-clang
 129 </pre>
 130
 131 <p>
 132 The default compilers depends on your operating system. Meson supports most of
 133 the popular compilers, a complete list is available
 134 <a href="http://mesonbuild.com/Reference-tables.html#compiler-ids">here</a>.
 135 </p>
 136
 137 <p>Meson also honors <code>DESTDIR</code> for installs</p>
 138 </dd>
 139
 140
 141 <dt><code>LLVM</code></dt>
 142 <dd><p>Meson includes upstream logic to wrap llvm-config using its standard
 143 dependency interface. It will search <code>$PATH</code> (or <code>%PATH%</code> on windows) for
 144 llvm-config (and llvm-config$version and llvm-config-$version), so using an
 145 LLVM from a non-standard path is as easy as
 146 <code>PATH=/path/with/llvm-config:$PATH meson build</code>.
 147 </p></dd>
 148 </dl>
 149
 150 <dl>
 151 <dt><code>PKG_CONFIG_PATH</code></dt>
 152 <dd><p>The
 153 <code>pkg-config</code> utility is a hard requirement for configuring and
 154 building Mesa on Unix-like systems. It is used to search for external libraries
 155 on the system. This environment variable is used to control the search path for
 156 <code>pkg-config</code>. For instance, setting
 157 <code>PKG_CONFIG_PATH=/usr/X11R6/lib/pkgconfig</code> will search for package
 158 metadata in <code>/usr/X11R6</code> before the standard directories.</p>
 159 </dd>
 160 </dl>
 161
 162 <p>
 163 One of the oddities of meson is that some options are different when passed to
 164 the <code>meson</code> than to <code>meson configure</code>. These options are
 165 passed as --option=foo to <code>meson</code>, but -Doption=foo to <code>meson
 166 configure</code>. Mesa defined options are always passed as -Doption=foo.
 167 </p>
 168
 169 <p>For those coming from autotools be aware of the following:</p>
 170
 171 <dl>
 172 <dt><code>--buildtype/-Dbuildtype</code></dt>
 173 <dd><p>This option will set the compiler debug/optimisation levels to aid
 174 debugging the Mesa libraries.</p>
 175
 176 <p>Note that in meson this defaults to <code>debugoptimized</code>, and
 177 not setting it to <code>release</code> will yield non-optimal
 178 performance and binary size. Not using <code>debug</code> may interfere
 179 with debugging as some code and validation will be optimized away.
 180 </p>
 181
 182 <p> For those wishing to pass their own optimization flags, use the <code>plain</code>
 183 buildtype, which causes meson to inject no additional compiler arguments, only
 184 those in the C/CXXFLAGS and those that mesa itself defines.</p>
 185 </dd>
 186 </dl>
 187
 188 <dl>
 189 <dt><code>-Db_ndebug</code></dt>
 190 <dd><p>This option controls assertions in meson projects. When set to <code>false</code>
 191 (the default) assertions are enabled, when set to true they are disabled. This
 192 is unrelated to the <code>buildtype</code>; setting the latter to
 193 <code>release</code> will not turn off assertions.
 194 </p>
 195 </dd>
 196 </dl>
 197
 198 <h2 id="cross-compilation">2. Cross-compilation and 32-bit builds</h2>
 199
 200 <p><a href="https://mesonbuild.com/Cross-compilation.html">Meson supports
 201 cross-compilation</a> by specifying a number of binary paths and
 202 settings in a file and passing this file to <code>meson</code> or
 203 <code>meson configure</code> with the <code>--cross-file</code>
 204 parameter.</p>
 205
 206 <p>This file can live at any location, but you can use the bare filename
 207 (without the folder path) if you put it in $XDG_DATA_HOME/meson/cross or
 208 ~/.local/share/meson/cross</p>
 209
 210 <p>Below are a few example of cross files, but keep in mind that you
 211 will likely have to alter them for your system.</p>
 212
 213 <p>
 214 32-bit build on x86 linux:
 215 <pre>
 216 [binaries]
 217 c = '/usr/bin/gcc'
 218 cpp = '/usr/bin/g++'
 219 ar = '/usr/bin/gcc-ar'
 220 strip = '/usr/bin/strip'
 221 pkgconfig = '/usr/bin/pkg-config-32'
 222 llvm-config = '/usr/bin/llvm-config32'
 223
 224 [properties]
 225 c_args = ['-m32']
 226 c_link_args = ['-m32']
 227 cpp_args = ['-m32']
 228 cpp_link_args = ['-m32']
 229
 230 [host_machine]
 231 system = 'linux'
 232 cpu_family = 'x86'
 233 cpu = 'i686'
 234 endian = 'little'
 235 </pre>
 236 </p>
 237
 238 <p>
 239 64-bit build on ARM linux:
 240 <pre>
 241 [binaries]
 242 c = '/usr/bin/aarch64-linux-gnu-gcc'
 243 cpp = '/usr/bin/aarch64-linux-gnu-g++'
 244 ar = '/usr/bin/aarch64-linux-gnu-ar'
 245 strip = '/usr/bin/aarch64-linux-gnu-strip'
 246 pkgconfig = '/usr/bin/aarch64-linux-gnu-pkg-config'
 247 exe_wrapper = '/usr/bin/qemu-aarch64-static'
 248
 249 [host_machine]
 250 system = 'linux'
 251 cpu_family = 'arm'
 252 cpu = 'aarch64'
 253 endian = 'little'
 254 </pre>
 255 </p>
 256
 257 <p>
 258 64-bit build on x86 windows:
 259 <pre>
 260 [binaries]
 261 c = '/usr/bin/x86_64-w64-mingw32-gcc'
 262 cpp = '/usr/bin/x86_64-w64-mingw32-g++'
 263 ar = '/usr/bin/x86_64-w64-mingw32-ar'
 264 strip = '/usr/bin/x86_64-w64-mingw32-strip'
 265 pkgconfig = '/usr/bin/x86_64-w64-mingw32-pkg-config'
 266 exe_wrapper = 'wine'
 267
 268 [host_machine]
 269 system = 'windows'
 270 cpu_family = 'x86_64'
 271 cpu = 'i686'
 272 endian = 'little'
 273 </pre>
 274 </p>
 275
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