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 </p>
  57
  58 <p>
  59 Meson does not currently support listing options before configure a build
  60 directory, but this feature is being discussed upstream.
  61 For now, we have a <code>bin/meson-options.py</code> script that prints
  62 the options for you.
  63 If that script doesn't work for some reason, you can always look in the
  64 <code>meson_options.txt</code> file at the root of the project.
  65 </p>
  66
  67 <pre>
  68     meson configure build/
  69 </pre>
  70
  71 <p>
  72 With additional arguments <code>meson configure</code> is used to change
  73 options on already configured build directory. All options passed to this
  74 command are in the form <code>-D "command"="value"</code>.
  75 </p>
  76
  77 <pre>
  78     meson configure build/ -Dprefix=/tmp/install -Dglx=true
  79 </pre>
  80
  81 <p>
  82 Note that options taking lists (such as <code>platforms</code>) are
  83 <a href="http://mesonbuild.com/Build-options.html#using-build-options">a bit
  84 more complicated</a>, but the simplest form compatible with Mesa options
  85 is to use a comma to separate values (<code>-D platforms=drm,wayland</code>)
  86 and brackets to represent an empty list (<code>-D platforms=[]</code>).
  87 </p>
  88
  89 <p>
  90 Once you've run the initial <code>meson</code> command successfully you can use
  91 your configured backend to build the project. With ninja, the -C option can be
  92 be used to point at a directory to build.
  93 </p>
  94
  95 <pre>
  96     ninja -C build/
  97 </pre>
  98
  99 <p>
 100 Without arguments, it will produce libGL.so and/or several other libraries
 101 depending on the options you have chosen. Later, if you want to rebuild for a
 102 different configuration, you should run <code>ninja clean</code> before
 103 changing the configuration, or create a new out of tree build directory for
 104 each configuration you want to build
 105 <a href="http://mesonbuild.com/Using-multiple-build-directories.html">as
 106 recommended in the documentation</a>
 107 </p>
 108
 109 <p>
 110 Autotools automatically updates translation files as part of the build process,
 111 meson does not do this. Instead if you want translated drirc files you will need
 112 to invoke non-default targets for ninja to update them:
 113 <code>ninja -C build/ xmlpool-pot xmlpool-update-po xmlpool-gmo</code>
 114 </p>
 115
 116 <dl>
 117 <dt><code>Environment Variables</code></dt>
 118 <dd><p>Meson supports the standard CC and CXX environment variables for
 119 changing the default compiler. Meson does support CFLAGS, CXXFLAGS, etc. But
 120 their use is discouraged because of the many caveats in using them. Instead it
 121 is recomended to use <code>-D${lang}_args</code> and
 122 <code>-D${lang}_link_args</code> instead. Among the benefits of these options
 123 is that they are guaranteed to persist across rebuilds and reconfigurations.
 124
 125 Meson does not allow changing compiler in a configured builddir, you will need
 126 to create a new build dir for a different compiler.
 127 </p>
 128
 129 <pre>
 130     CC=clang CXX=clang++ meson build-clang
 131     ninja -C build-clang
 132     ninja -C build-clang clean
 133     meson configure build -Dc_args="-Wno-typedef-redefinition"
 134     ninja -C build-clang
 135 </pre>
 136
 137 <p>
 138 The default compilers depends on your operating system. Meson supports most of
 139 the popular compilers, a complete list is available
 140 <a href="http://mesonbuild.com/Reference-tables.html#compiler-ids">here</a>.
 141 </p>
 142
 143 <p>Meson also honors <code>DESTDIR</code> for installs</p>
 144 </dd>
 145
 146
 147 <dt><code>LLVM</code></dt>
 148 <dd><p>Meson includes upstream logic to wrap llvm-config using its standard
 149 dependency interface.
 150 </p></dd>
 151
 152 <dd><p>
 153 As of meson 0.49.0 meson also has the concept of a
 154 <a href="https://mesonbuild.com/Native-environments.html">"native file"</a>,
 155 these files provide information about the native build environment (as opposed
 156 to a cross build environment). They are ini formatted and can override where to
 157 find llvm-config:
 158
 159 custom-llvm.ini
 160 <pre>
 161     [binaries]
 162     llvm-config = '/usr/local/bin/llvm/llvm-config'
 163 </pre>
 164
 165 Then configure meson:
 166
 167 <pre>
 168     meson builddir/ --native-file custom-llvm.ini
 169 </pre>
 170 </p></dd>
 171
 172 <dd><p>
 173 For selecting llvm-config for cross compiling a
 174 <a href="https://mesonbuild.com/Cross-compilation.html#defining-the-environment">"cross file"</a>
 175 should be used. It uses the same format as the native file above:
 176
 177 cross-llvm.ini
 178 <pre>
 179     [binaries]
 180     ...
 181     llvm-config = '/usr/lib/llvm-config-32'
 182 </pre>
 183
 184 Then configure meson:
 185
 186 <pre>
 187     meson builddir/ --cross-file cross-llvm.ini
 188 </pre>
 189
 190 See the <a href="#cross-compilation">Cross Compilation</a> section for more information.
 191 </dd></p>
 192
 193 <dd><p>
 194 For older versions of meson <code>$PATH</code> (or <code>%PATH%</code> on
 195 windows) will be searched for llvm-config (and llvm-config$version and
 196 llvm-config-$version), you can override this environment variable to control
 197 the search: <code>PATH=/path/with/llvm-config:$PATH meson build</code>.
 198 </dd></p>
 199 </dl>
 200
 201 <dl>
 202 <dt><code>PKG_CONFIG_PATH</code></dt>
 203 <dd><p>The
 204 <code>pkg-config</code> utility is a hard requirement for configuring and
 205 building Mesa on Unix-like systems. It is used to search for external libraries
 206 on the system. This environment variable is used to control the search path for
 207 <code>pkg-config</code>. For instance, setting
 208 <code>PKG_CONFIG_PATH=/usr/X11R6/lib/pkgconfig</code> will search for package
 209 metadata in <code>/usr/X11R6</code> before the standard directories.</p>
 210 </dd>
 211 </dl>
 212
 213 <p>
 214 One of the oddities of meson is that some options are different when passed to
 215 the <code>meson</code> than to <code>meson configure</code>. These options are
 216 passed as --option=foo to <code>meson</code>, but -Doption=foo to <code>meson
 217 configure</code>. Mesa defined options are always passed as -Doption=foo.
 218 </p>
 219
 220 <p>For those coming from autotools be aware of the following:</p>
 221
 222 <dl>
 223 <dt><code>--buildtype/-Dbuildtype</code></dt>
 224 <dd><p>This option will set the compiler debug/optimisation levels to aid
 225 debugging the Mesa libraries.</p>
 226
 227 <p>Note that in meson this defaults to <code>debugoptimized</code>, and
 228 not setting it to <code>release</code> will yield non-optimal
 229 performance and binary size. Not using <code>debug</code> may interfere
 230 with debugging as some code and validation will be optimized away.
 231 </p>
 232
 233 <p> For those wishing to pass their own optimization flags, use the <code>plain</code>
 234 buildtype, which causes meson to inject no additional compiler arguments, only
 235 those in the C/CXXFLAGS and those that mesa itself defines.</p>
 236 </dd>
 237 </dl>
 238
 239 <dl>
 240 <dt><code>-Db_ndebug</code></dt>
 241 <dd><p>This option controls assertions in meson projects. When set to <code>false</code>
 242 (the default) assertions are enabled, when set to true they are disabled. This
 243 is unrelated to the <code>buildtype</code>; setting the latter to
 244 <code>release</code> will not turn off assertions.
 245 </p>
 246 </dd>
 247 </dl>
 248
 249 <h2 id="cross-compilation">2. Cross-compilation and 32-bit builds</h2>
 250
 251 <p><a href="https://mesonbuild.com/Cross-compilation.html">Meson supports
 252 cross-compilation</a> by specifying a number of binary paths and
 253 settings in a file and passing this file to <code>meson</code> or
 254 <code>meson configure</code> with the <code>--cross-file</code>
 255 parameter.</p>
 256
 257 <p>This file can live at any location, but you can use the bare filename
 258 (without the folder path) if you put it in $XDG_DATA_HOME/meson/cross or
 259 ~/.local/share/meson/cross</p>
 260
 261 <p>Below are a few example of cross files, but keep in mind that you
 262 will likely have to alter them for your system.</p>
 263
 264 <p>
 265 Those running on ArchLinux can use the AUR-maintained packages for some
 266 of those, as they'll have the right values for your system:
 267 <ul>
 268   <li><a href="https://aur.archlinux.org/packages/meson-cross-x86-linux-gnu">meson-cross-x86-linux-gnu</a></li>
 269   <li><a href="https://aur.archlinux.org/packages/meson-cross-aarch64-linux-gnu">meson-cross-aarch64-linux-gnu</a></li>
 270 </ul>
 271 </p>
 272
 273 <p>
 274 32-bit build on x86 linux:
 275 <pre>
 276 [binaries]
 277 c = '/usr/bin/gcc'
 278 cpp = '/usr/bin/g++'
 279 ar = '/usr/bin/gcc-ar'
 280 strip = '/usr/bin/strip'
 281 pkgconfig = '/usr/bin/pkg-config-32'
 282 llvm-config = '/usr/bin/llvm-config32'
 283
 284 [properties]
 285 c_args = ['-m32']
 286 c_link_args = ['-m32']
 287 cpp_args = ['-m32']
 288 cpp_link_args = ['-m32']
 289
 290 [host_machine]
 291 system = 'linux'
 292 cpu_family = 'x86'
 293 cpu = 'i686'
 294 endian = 'little'
 295 </pre>
 296 </p>
 297
 298 <p>
 299 64-bit build on ARM linux:
 300 <pre>
 301 [binaries]
 302 c = '/usr/bin/aarch64-linux-gnu-gcc'
 303 cpp = '/usr/bin/aarch64-linux-gnu-g++'
 304 ar = '/usr/bin/aarch64-linux-gnu-gcc-ar'
 305 strip = '/usr/bin/aarch64-linux-gnu-strip'
 306 pkgconfig = '/usr/bin/aarch64-linux-gnu-pkg-config'
 307 exe_wrapper = '/usr/bin/qemu-aarch64-static'
 308
 309 [host_machine]
 310 system = 'linux'
 311 cpu_family = 'aarch64'
 312 cpu = 'aarch64'
 313 endian = 'little'
 314 </pre>
 315 </p>
 316
 317 <p>
 318 64-bit build on x86 windows:
 319 <pre>
 320 [binaries]
 321 c = '/usr/bin/x86_64-w64-mingw32-gcc'
 322 cpp = '/usr/bin/x86_64-w64-mingw32-g++'
 323 ar = '/usr/bin/x86_64-w64-mingw32-ar'
 324 strip = '/usr/bin/x86_64-w64-mingw32-strip'
 325 pkgconfig = '/usr/bin/x86_64-w64-mingw32-pkg-config'
 326 exe_wrapper = 'wine'
 327
 328 [host_machine]
 329 system = 'windows'
 330 cpu_family = 'x86_64'
 331 cpu = 'i686'
 332 endian = 'little'
 333 </pre>
 334 </p>
 335
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