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  11   The Mesa 3D Graphics Library
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  16
  17 <h1>Compilation and Installation Using Meson</h1>
  18
  19 <ul>
  20   <li><a href="#intro">Introduction</a></li>
  21   <li><a href="#basic">Basic Usage</a></li>
  22   <li><a href="#advanced">Advanced Usage</a></li>
  23   <li><a href="#cross-compilation">Cross-compilation and 32-bit builds</a></li>
  24 </ul>
  25
  26 <h2 id="intro">1. Introduction</h2>
  27
  28 <p>For general information about Meson see the
  29 <a href="http://mesonbuild.com/">Meson website</a>.</p>
  30
  31 <p><strong>Mesa's Meson build system is generally considered stable and ready
  32 for production.</strong></p>
  33
  34 <p>The Meson build of Mesa is tested on Linux, macOS, Cygwin and Haiku, FreeBSD,
  35 DragonflyBSD, NetBSD, and should work on OpenBSD.</p>
  36
  37 <p>If Meson is not already installed on your system, you can typically
  38 install it with your package installer.  For example:</p>
  39 <pre>
  40 sudo apt-get install meson   # Ubuntu
  41 </pre>
  42 or
  43 <pre>
  44 sudo dnf install meson   # Fedora
  45 </pre>
  46
  47 <p><strong>Mesa requires Meson &gt;= 0.46.0 to build.</strong>
  48
  49 Some older versions of meson do not check that they are too old and will error
  50 out in odd ways.
  51 </p>
  52
  53 <p>You'll also need <a href="https://ninja-build.org/">Ninja</a>.
  54 If it's not already installed, use apt-get or dnf to install
  55 the <em>ninja-build</em> package.
  56 </p>
  57
  58 <h2 id="basic">2. Basic Usage</h2>
  59
  60 <p>
  61 The meson program is used to configure the source directory and generates
  62 either a ninja build file or Visual Studio® build files. The latter must
  63 be enabled via the <code>--backend</code> switch, as ninja is the default
  64 backend on all
  65 operating systems.
  66 </p>
  67
  68 <p>
  69 Meson only supports out-of-tree builds, and must be passed a
  70 directory to put built and generated sources into. We'll call that directory
  71 "build" here.
  72 It's recommended to create a
  73 <a href="http://mesonbuild.com/Using-multiple-build-directories.html">
  74 separate build directory</a> for each configuration you might want to use.
  75 </p>
  76
  77
  78
  79 <p>Basic configuration is done with:</p>
  80
  81 <pre>
  82 meson build/
  83 </pre>
  84
  85 <p>
  86 This will create the build directory.
  87 If any dependencies are missing, you can install them, or try to remove
  88 the dependency with a Meson configuration option (see below).
  89 </p>
  90
  91 <p>
  92 To review the options which Meson chose, run:
  93 </p>
  94 <pre>
  95 meson configure build/
  96 </pre>
  97
  98 <p>
  99 Meson does not currently support listing configuration options before
 100 running "meson build/" but this feature is being discussed upstream.
 101 For now, we have a <code>bin/meson-options.py</code> script that prints
 102 the options for you.
 103 If that script doesn't work for some reason, you can always look in the
 104 <a href="https://gitlab.freedesktop.org/mesa/mesa/blob/master/meson_options.txt">
 105 meson_options.txt</a> file at the root of the project.
 106 </p>
 107
 108 <p>
 109 With additional arguments <code>meson configure</code> can be used to change
 110 options for a previously configured build directory.
 111 All options passed to this command are in the form
 112 <code>-D "option"="value"</code>.
 113 For example:
 114 </p>
 115
 116 <pre>
 117 meson configure build/ -Dprefix=/tmp/install -Dglx=true
 118 </pre>
 119
 120 <p>
 121 Note that options taking lists (such as <code>platforms</code>) are
 122 <a href="http://mesonbuild.com/Build-options.html#using-build-options">a bit
 123 more complicated</a>, but the simplest form compatible with Mesa options
 124 is to use a comma to separate values (<code>-D platforms=drm,wayland</code>)
 125 and brackets to represent an empty list (<code>-D platforms=[]</code>).
 126 </p>
 127
 128 <p>
 129 Once you've run the initial <code>meson</code> command successfully you can use
 130 your configured backend to build the project in your build directory:
 131 </p>
 132
 133 <pre>
 134 ninja -C build/
 135 </pre>
 136
 137 <p>
 138 The next step is to install the Mesa libraries, drivers, etc.
 139 This also finishes up some final steps of the build process (such as creating
 140 symbolic links for drivers).  To install:
 141 </p>
 142
 143 <pre>
 144 ninja -C build/ install
 145 </pre>
 146
 147 <p>
 148 Note: autotools automatically updated translation files (used by the DRI
 149 configuration tool) as part of the build process,
 150 Meson does not do this.  Instead, you will need do this:
 151 </p>
 152 <pre>
 153 ninja -C build/ xmlpool-pot xmlpool-update-po xmlpool-gmo
 154 </pre>
 155
 156 <h2 id="advanced">3. Advanced Usage</h2>
 157
 158 <dl>
 159
 160 <dt>Installation Location</dt>
 161 <dd>
 162 <p>
 163 Meson default to installing libGL.so in your system's main lib/ directory
 164 and DRI drivers to a dri/ subdirectory.
 165 </p>
 166 <p>
 167 Developers will often want to install Mesa to a testing directory rather
 168 than the system library directory.
 169 This can be done with the --prefix option.  For example:
 170 </p>
 171 <pre>
 172 meson --prefix="${PWD}/build/install" build/
 173 </pre>
 174 <p>
 175 will put the final libraries and drivers into the build/install/
 176 directory.
 177 Then you can set LD_LIBRARY_PATH and LIBGL_DRIVERS_PATH to that location
 178 to run/test the driver.
 179 </p>
 180 <p>
 181 Meson also honors <code>DESTDIR</code> for installs.
 182 </p>
 183 </dd>
 184
 185 <dt>Compiler Options</dt>
 186 <dd>
 187 <p>Meson supports the common CFLAGS, CXXFLAGS, etc. environment
 188 variables but their use is discouraged because of the many caveats
 189 in using them.
 190 </p>
 191 <p>Instead, it is recomended to use <code>-D${lang}_args</code> and
 192 <code>-D${lang}_link_args</code>. Among the benefits of these options
 193 is that they are guaranteed to persist across rebuilds and reconfigurations.
 194 </p>
 195 <p>
 196 This example sets -fmax-errors for compiling C sources and -DMAGIC=123
 197 for C++ sources:
 198 </p>
 199 <pre>
 200 meson builddir/ -Dc_args=-fmax-errors=10 -Dcpp_args=-DMAGIC=123
 201 </pre>
 202 </dd>
 203
 204
 205 <dt>Compiler Specification</dt>
 206 <dd>
 207 <p>
 208 Meson supports the standard CC and CXX environment variables for
 209 changing the default compiler.  Note that Meson does not allow
 210 changing the compilers in a configured builddir so you will need
 211 to create a new build dir for a different compiler.
 212 </p>
 213 <p>
 214 This is an example of specifying the clang compilers and cleaning
 215 the build directory before reconfiguring with an extra C option:
 216 </p>
 217 <pre>
 218 CC=clang CXX=clang++ meson build-clang
 219 ninja -C build-clang
 220 ninja -C build-clang clean
 221 meson configure build -Dc_args="-Wno-typedef-redefinition"
 222 ninja -C build-clang
 223 </pre>
 224 <p>
 225 The default compilers depends on your operating system. Meson supports most of
 226 the popular compilers, a complete list is available
 227 <a href="http://mesonbuild.com/Reference-tables.html#compiler-ids">here</a>.
 228 </p>
 229 </dd>
 230
 231 <dt>LLVM</dt>
 232 <dd><p>Meson includes upstream logic to wrap llvm-config using its standard
 233 dependency interface.
 234 </p></dd>
 235
 236 <dd><p>
 237 As of meson 0.49.0 meson also has the concept of a
 238 <a href="https://mesonbuild.com/Native-environments.html">"native file"</a>,
 239 these files provide information about the native build environment (as opposed
 240 to a cross build environment). They are ini formatted and can override where to
 241 find llvm-config:
 242 </p>
 243
 244 custom-llvm.ini
 245 <pre>
 246     [binaries]
 247     llvm-config = '/usr/local/bin/llvm/llvm-config'
 248 </pre>
 249
 250 Then configure meson:
 251
 252 <pre>
 253     meson builddir/ --native-file custom-llvm.ini
 254 </pre>
 255 </dd>
 256
 257 <dd><p>
 258 Meson &lt; 0.49 doesn't support native files, so to specify a custom
 259 <code>llvm-config</code> you need to modify your <code>$PATH</code> (or
 260 <code>%PATH%</code> on windows), which will be searched for
 261 <code>llvm-config</code>, <code>llvm-config<i>$version</i></code>,
 262 and <code>llvm-config-<i>$version</i></code>:
 263 </p>
 264 <pre>
 265 PATH=/path/to/folder/with/llvm-config:$PATH meson build
 266 </pre>
 267 </dd>
 268
 269 <dd><p>
 270 For selecting llvm-config for cross compiling a
 271 <a href="https://mesonbuild.com/Cross-compilation.html#defining-the-environment">"cross file"</a>
 272 should be used. It uses the same format as the native file above:
 273 </p>
 274
 275 <p>cross-llvm.ini</p>
 276 <pre>
 277     [binaries]
 278     ...
 279     llvm-config = '/usr/lib/llvm-config-32'
 280 </pre>
 281
 282 <p>Then configure meson:</p>
 283 <pre>
 284     meson builddir/ --cross-file cross-llvm.ini
 285 </pre>
 286
 287 See the <a href="#cross-compilation">Cross Compilation</a> section for more information.
 288 </dd>
 289
 290 <dt><code>PKG_CONFIG_PATH</code></dt>
 291 <dd><p>The
 292 <code>pkg-config</code> utility is a hard requirement for configuring and
 293 building Mesa on Unix-like systems. It is used to search for external libraries
 294 on the system. This environment variable is used to control the search path for
 295 <code>pkg-config</code>. For instance, setting
 296 <code>PKG_CONFIG_PATH=/usr/X11R6/lib/pkgconfig</code> will search for package
 297 metadata in <code>/usr/X11R6</code> before the standard directories.</p>
 298 </dd>
 299 </dl>
 300
 301 <p>
 302 One of the oddities of meson is that some options are different when passed to
 303 the <code>meson</code> than to <code>meson configure</code>. These options are
 304 passed as --option=foo to <code>meson</code>, but -Doption=foo to <code>meson
 305 configure</code>. Mesa defined options are always passed as -Doption=foo.
 306 </p>
 307
 308 <p>For those coming from autotools be aware of the following:</p>
 309
 310 <dl>
 311 <dt><code>--buildtype/-Dbuildtype</code></dt>
 312 <dd><p>This option will set the compiler debug/optimisation levels to aid
 313 debugging the Mesa libraries.</p>
 314
 315 <p>Note that in meson this defaults to <code>debugoptimized</code>, and
 316 not setting it to <code>release</code> will yield non-optimal
 317 performance and binary size. Not using <code>debug</code> may interfere
 318 with debugging as some code and validation will be optimized away.
 319 </p>
 320
 321 <p> For those wishing to pass their own optimization flags, use the <code>plain</code>
 322 buildtype, which causes meson to inject no additional compiler arguments, only
 323 those in the C/CXXFLAGS and those that mesa itself defines.</p>
 324 </dd>
 325
 326 <dt><code>-Db_ndebug</code></dt>
 327 <dd><p>This option controls assertions in meson projects. When set to <code>false</code>
 328 (the default) assertions are enabled, when set to true they are disabled. This
 329 is unrelated to the <code>buildtype</code>; setting the latter to
 330 <code>release</code> will not turn off assertions.
 331 </p>
 332 </dd>
 333 </dl>
 334
 335 <h2 id="cross-compilation">4. Cross-compilation and 32-bit builds</h2>
 336
 337 <p><a href="https://mesonbuild.com/Cross-compilation.html">Meson supports
 338 cross-compilation</a> by specifying a number of binary paths and
 339 settings in a file and passing this file to <code>meson</code> or
 340 <code>meson configure</code> with the <code>--cross-file</code>
 341 parameter.</p>
 342
 343 <p>This file can live at any location, but you can use the bare filename
 344 (without the folder path) if you put it in $XDG_DATA_HOME/meson/cross or
 345 ~/.local/share/meson/cross</p>
 346
 347 <p>Below are a few example of cross files, but keep in mind that you
 348 will likely have to alter them for your system.</p>
 349
 350 <p>
 351 Those running on ArchLinux can use the AUR-maintained packages for some
 352 of those, as they'll have the right values for your system:
 353 </p>
 354 <ul>
 355   <li><a href="https://aur.archlinux.org/packages/meson-cross-x86-linux-gnu">meson-cross-x86-linux-gnu</a></li>
 356   <li><a href="https://aur.archlinux.org/packages/meson-cross-aarch64-linux-gnu">meson-cross-aarch64-linux-gnu</a></li>
 357 </ul>
 358
 359 <p>
 360 32-bit build on x86 linux:
 361 </p>
 362 <pre>
 363 [binaries]
 364 c = '/usr/bin/gcc'
 365 cpp = '/usr/bin/g++'
 366 ar = '/usr/bin/gcc-ar'
 367 strip = '/usr/bin/strip'
 368 pkgconfig = '/usr/bin/pkg-config-32'
 369 llvm-config = '/usr/bin/llvm-config32'
 370
 371 [properties]
 372 c_args = ['-m32']
 373 c_link_args = ['-m32']
 374 cpp_args = ['-m32']
 375 cpp_link_args = ['-m32']
 376
 377 [host_machine]
 378 system = 'linux'
 379 cpu_family = 'x86'
 380 cpu = 'i686'
 381 endian = 'little'
 382 </pre>
 383
 384 <p>
 385 64-bit build on ARM linux:
 386 </p>
 387 <pre>
 388 [binaries]
 389 c = '/usr/bin/aarch64-linux-gnu-gcc'
 390 cpp = '/usr/bin/aarch64-linux-gnu-g++'
 391 ar = '/usr/bin/aarch64-linux-gnu-gcc-ar'
 392 strip = '/usr/bin/aarch64-linux-gnu-strip'
 393 pkgconfig = '/usr/bin/aarch64-linux-gnu-pkg-config'
 394 exe_wrapper = '/usr/bin/qemu-aarch64-static'
 395
 396 [host_machine]
 397 system = 'linux'
 398 cpu_family = 'aarch64'
 399 cpu = 'aarch64'
 400 endian = 'little'
 401 </pre>
 402
 403 <p>
 404 64-bit build on x86 windows:
 405 </p>
 406 <pre>
 407 [binaries]
 408 c = '/usr/bin/x86_64-w64-mingw32-gcc'
 409 cpp = '/usr/bin/x86_64-w64-mingw32-g++'
 410 ar = '/usr/bin/x86_64-w64-mingw32-ar'
 411 strip = '/usr/bin/x86_64-w64-mingw32-strip'
 412 pkgconfig = '/usr/bin/x86_64-w64-mingw32-pkg-config'
 413 exe_wrapper = 'wine'
 414
 415 [host_machine]
 416 system = 'windows'
 417 cpu_family = 'x86_64'
 418 cpu = 'i686'
 419 endian = 'little'
 420 </pre>
 421
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