docs/meson.rst

   1 Compilation and Installation Using Meson
   2 ========================================
   3
   4 1. Introduction
   5 ---------------
   6
   7 For general information about Meson see the `Meson
   8 website <https://mesonbuild.com/>`__.
   9
  10 **Mesa's Meson build system is generally considered stable and ready for
  11 production.**
  12
  13 .. note::
  14
  15    Mesa requires Meson >= 0.52.0 to build.
  16
  17    If your distribution doesn't have something recent enough in its
  18    repositories, you can `try the methods suggested here
  19    <https://mesonbuild.com/Getting-meson.html>`__ to install the
  20    current version of Meson.
  21
  22 The Meson build of Mesa is tested on Linux, macOS, Windows, Cygwin,
  23 Haiku, FreeBSD, DragonflyBSD, NetBSD, and should work on OpenBSD.
  24
  25 Unix-like OSes
  26 ^^^^^^^^^^^^^^
  27
  28 If Meson is not already installed on your system, you can typically
  29 install it with your package installer. For example:
  30
  31 .. code-block:: console
  32
  33    sudo apt-get install meson   # Ubuntu
  34
  35 or
  36
  37 .. code-block:: console
  38
  39    sudo dnf install meson   # Fedora
  40
  41 Some older versions of meson do not check that they are too old and will
  42 error out in odd ways.
  43
  44 You'll also need `Ninja <https://ninja-build.org/>`__. If it's not
  45 already installed, use apt-get or dnf to install the *ninja-build*
  46 package.
  47
  48 Windows
  49 ^^^^^^^
  50
  51 You will need to install python3 and meson as a module using pip. This
  52 is because we use python for generating code, and rely on external
  53 modules (mako). You also need pkg-config (a hard dependency of meson),
  54 flex, and bison. The easiest way to install everything you need is with
  55 `chocolatey <https://chocolatey.org/>`__.
  56
  57 .. code-block:: console
  58
  59    choco install python3 winflexbison pkgconfiglite
  60
  61 You can even use chocolatey to install mingw and ninja (ninja can be
  62 used with MSVC as well)
  63
  64 .. code-block:: console
  65
  66    choco install ninja mingw
  67
  68 Then install meson using pip
  69
  70 .. code-block:: console
  71
  72    py -3 -m pip install meson mako
  73
  74 You may need to add the python3 scripts directory to your path for
  75 meson.
  76
  77 2. Basic Usage
  78 --------------
  79
  80 The meson program is used to configure the source directory and
  81 generates either a ninja build file or Visual Studio® build files. The
  82 latter must be enabled via the ``--backend`` switch, as ninja is the
  83 default backend on all operating systems.
  84
  85 Meson only supports out-of-tree builds, and must be passed a directory
  86 to put built and generated sources into. We'll call that directory
  87 "build" here. It's recommended to create a `separate build
  88 directory <https://mesonbuild.com/Using-multiple-build-directories.html>`__
  89 for each configuration you might want to use.
  90
  91 Basic configuration is done with:
  92
  93 .. code-block:: console
  94
  95    meson build/
  96
  97 This will create the build directory. If any dependencies are missing,
  98 you can install them, or try to remove the dependency with a Meson
  99 configuration option (see below).
 100
 101 To review the options which Meson chose, run:
 102
 103 .. code-block:: console
 104
 105    meson configure build/
 106
 107 Meson does not currently support listing configuration options before
 108 running "meson build/" but this feature is being discussed upstream. For
 109 now, we have a ``bin/meson-options.py`` script that prints the options
 110 for you. If that script doesn't work for some reason, you can always
 111 look in the
 112 `meson_options.txt <https://gitlab.freedesktop.org/mesa/mesa/-/blob/master/meson_options.txt>`__
 113 file at the root of the project.
 114
 115 With additional arguments ``meson configure`` can be used to change
 116 options for a previously configured build directory. All options passed
 117 to this command are in the form ``-D "option"="value"``. For example:
 118
 119 .. code-block:: console
 120
 121    meson configure build/ -Dprefix=/tmp/install -Dglx=true
 122
 123 Note that options taking lists (such as ``platforms``) are `a bit more
 124 complicated <https://mesonbuild.com/Build-options.html#using-build-options>`__,
 125 but the simplest form compatible with Mesa options is to use a comma to
 126 separate values (``-D platforms=drm,wayland``) and brackets to represent
 127 an empty list (``-D platforms=[]``).
 128
 129 Once you've run the initial ``meson`` command successfully you can use
 130 your configured backend to build the project in your build directory:
 131
 132 .. code-block:: console
 133
 134    ninja -C build/
 135
 136 The next step is to install the Mesa libraries, drivers, etc. This also
 137 finishes up some final steps of the build process (such as creating
 138 symbolic links for drivers). To install:
 139
 140 .. code-block:: console
 141
 142    ninja -C build/ install
 143
 144 .. note::
 145
 146    autotools automatically updated translation files (used by the DRI
 147    configuration tool) as part of the build process, Meson does not do
 148    this. Instead, you will need do this:
 149
 150    .. code-block:: console
 151
 152       ninja -C build/ xmlpool-pot xmlpool-update-po xmlpool-gmo
 153
 154 Windows specific instructions
 155 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 156
 157 On windows you have a couple of choices for compilers. If you installed
 158 mingw with chocolatey and want to use ninja you should be able to open
 159 any shell and follow the instructions above. If you want to you MSVC,
 160 clang-cl, or ICL (the Intel Compiler), read on.
 161
 162 Both ICL and MSVC come with shell environments, the easiest way to use
 163 meson with these it to open a shell. For clang-cl you will need to open
 164 an MSVC shell, and then override the compilers, either using a `native
 165 file <https://mesonbuild.com/Native-environments.html>`__, or with the
 166 CC and CXX environment variables.
 167
 168 All of these compilers are tested and work with ninja, but if you want
 169 visual studio integration or you just like msbuild, passing
 170 ``--backend=vs`` to meson will generate a visual studio solution. If you
 171 want to use ICL or clang-cl with the vsbackend you will need meson
 172 0.52.0 or greater. Older versions always use the microsoft compiler.
 173
 174 3. Advanced Usage
 175 -----------------
 176
 177 Installation Location
 178 ^^^^^^^^^^^^^^^^^^^^^
 179
 180 Meson default to installing libGL.so in your system's main lib/
 181 directory and DRI drivers to a dri/ subdirectory.
 182
 183 Developers will often want to install Mesa to a testing directory rather
 184 than the system library directory. This can be done with the --prefix
 185 option. For example:
 186
 187 .. code-block:: console
 188
 189    meson --prefix="${PWD}/build/install" build/
 190
 191 will put the final libraries and drivers into the build/install/
 192 directory. Then you can set LD_LIBRARY_PATH and LIBGL_DRIVERS_PATH to
 193 that location to run/test the driver.
 194
 195 Meson also honors ``DESTDIR`` for installs.
 196
 197 Compiler Options
 198 ^^^^^^^^^^^^^^^^
 199
 200 Meson supports the common CFLAGS, CXXFLAGS, etc. environment variables
 201 but their use is discouraged because of the many caveats in using them.
 202
 203 Instead, it is recomended to use ``-D${lang}_args`` and
 204 ``-D${lang}_link_args``. Among the benefits of these options is that
 205 they are guaranteed to persist across rebuilds and reconfigurations.
 206
 207 This example sets -fmax-errors for compiling C sources and -DMAGIC=123
 208 for C++ sources:
 209
 210 .. code-block:: console
 211
 212    meson builddir/ -Dc_args=-fmax-errors=10 -Dcpp_args=-DMAGIC=123
 213
 214 Compiler Specification
 215 ^^^^^^^^^^^^^^^^^^^^^^
 216
 217 Meson supports the standard CC and CXX environment variables for
 218 changing the default compiler. Note that Meson does not allow changing
 219 the compilers in a configured builddir so you will need to create a new
 220 build dir for a different compiler.
 221
 222 This is an example of specifying the clang compilers and cleaning the
 223 build directory before reconfiguring with an extra C option:
 224
 225 .. code-block:: console
 226
 227    CC=clang CXX=clang++ meson build-clang
 228    ninja -C build-clang
 229    ninja -C build-clang clean
 230    meson configure build -Dc_args="-Wno-typedef-redefinition"
 231    ninja -C build-clang
 232
 233 The default compilers depends on your operating system. Meson supports
 234 most of the popular compilers, a complete list is available
 235 `here <https://mesonbuild.com/Reference-tables.html#compiler-ids>`__.
 236
 237 LLVM
 238 ^^^^
 239
 240 Meson includes upstream logic to wrap llvm-config using its standard
 241 dependency interface.
 242
 243 As of meson 0.51.0 meson can use cmake to find llvm (the cmake finder
 244 was added in meson 0.49.0, but LLVM cannot be found until 0.51) Due to
 245 the way LLVM implements its cmake finder it will only find static
 246 libraries, it will never find libllvm.so. There is also a
 247 ``-Dcmake_module_path`` option in this meson version, which points to
 248 the root of an alternative installation (the prefix). For example:
 249
 250 .. code-block:: console
 251
 252    meson builddir -Dcmake_module_path=/home/user/mycmake/prefix
 253
 254 As of meson 0.49.0 meson also has the concept of a `"native
 255 file" <https://mesonbuild.com/Native-environments.html>`__, these files
 256 provide information about the native build environment (as opposed to a
 257 cross build environment). They are ini formatted and can override where
 258 to find llvm-config:
 259
 260 custom-llvm.ini
 261
 262 ::
 263
 264    [binaries]
 265    llvm-config = '/usr/local/bin/llvm/llvm-config'
 266
 267 Then configure meson:
 268
 269 .. code-block:: console
 270
 271    meson builddir/ --native-file custom-llvm.ini
 272
 273 Meson < 0.49 doesn't support native files, so to specify a custom
 274 ``llvm-config`` you need to modify your ``$PATH`` (or ``%PATH%`` on
 275 windows), which will be searched for ``llvm-config``,
 276 ``llvm-config$version``, and ``llvm-config-$version``:
 277
 278 .. code-block:: console
 279
 280    PATH=/path/to/folder/with/llvm-config:$PATH meson build
 281
 282 For selecting llvm-config for cross compiling a `"cross
 283 file" <https://mesonbuild.com/Cross-compilation.html#defining-the-environment>`__
 284 should be used. It uses the same format as the native file above:
 285
 286 cross-llvm.ini
 287
 288 ::
 289
 290    [binaries]
 291    ...
 292    llvm-config = '/usr/lib/llvm-config-32'
 293    cmake = '/usr/bin/cmake-for-my-arch'
 294
 295 Obviously, only cmake or llvm-config is required.
 296
 297 Then configure meson:
 298
 299 .. code-block:: console
 300
 301    meson builddir/ --cross-file cross-llvm.ini
 302
 303 See the `Cross Compilation <#cross-compilation>`__ section for more
 304 information.
 305
 306 On windows (and in other cases), using llvm-config or cmake may be
 307 either undesirable or impossible. Meson's solution for this is a
 308 `wrap <https://mesonbuild.com/Wrap-dependency-system-manual.html>`__, in
 309 this case a "binary wrap". Follow the steps below:
 310
 311 -  Install the binaries and headers into the
 312    ``$mesa_src/subprojects/llvm``
 313 -  Add a meson build.build file to that directory (more on that later)
 314
 315 The wrap file must define the following:
 316
 317 -  ``dep_llvm``: a ``declare_dependency()`` object with
 318    include_directories, dependencies, and version set)
 319
 320 It may also define:
 321
 322 -  ``irbuilder_h``: a ``files()`` object pointing to llvm/IR/IRBuilder.h
 323    (this is requred for SWR)
 324 -  ``has_rtti``: a ``bool`` that declares whether LLVM was built with
 325    RTTI. Defaults to true
 326
 327 such a meson.build file might look like:
 328
 329 ::
 330
 331    project('llvm', ['cpp'])
 332
 333    cpp = meson.get_compiler('cpp')
 334
 335    _deps = []
 336    _search = join_paths(meson.current_source_dir(), 'lib')
 337    foreach d : ['libLLVMCodeGen', 'libLLVMScalarOpts', 'libLLVMAnalysis',
 338                 'libLLVMTransformUtils', 'libLLVMCore', 'libLLVMX86CodeGen',
 339                 'libLLVMSelectionDAG', 'libLLVMipo', 'libLLVMAsmPrinter',
 340                 'libLLVMInstCombine', 'libLLVMInstrumentation', 'libLLVMMC',
 341                 'libLLVMGlobalISel', 'libLLVMObjectYAML', 'libLLVMDebugInfoPDB',
 342                 'libLLVMVectorize', 'libLLVMPasses', 'libLLVMSupport',
 343                 'libLLVMLTO', 'libLLVMObject', 'libLLVMDebugInfoCodeView',
 344                 'libLLVMDebugInfoDWARF', 'libLLVMOrcJIT', 'libLLVMProfileData',
 345                 'libLLVMObjCARCOpts', 'libLLVMBitReader', 'libLLVMCoroutines',
 346                 'libLLVMBitWriter', 'libLLVMRuntimeDyld', 'libLLVMMIRParser',
 347                 'libLLVMX86Desc', 'libLLVMAsmParser', 'libLLVMTableGen',
 348                 'libLLVMFuzzMutate', 'libLLVMLinker', 'libLLVMMCParser',
 349                 'libLLVMExecutionEngine', 'libLLVMCoverage', 'libLLVMInterpreter',
 350                 'libLLVMTarget', 'libLLVMX86AsmParser', 'libLLVMSymbolize',
 351                 'libLLVMDebugInfoMSF', 'libLLVMMCJIT', 'libLLVMXRay',
 352                 'libLLVMX86AsmPrinter', 'libLLVMX86Disassembler',
 353                 'libLLVMMCDisassembler', 'libLLVMOption', 'libLLVMIRReader',
 354                 'libLLVMLibDriver', 'libLLVMDlltoolDriver', 'libLLVMDemangle',
 355                 'libLLVMBinaryFormat', 'libLLVMLineEditor',
 356                 'libLLVMWindowsManifest', 'libLLVMX86Info', 'libLLVMX86Utils']
 357      _deps += cpp.find_library(d, dirs : _search)
 358    endforeach
 359
 360    dep_llvm = declare_dependency(
 361      include_directories : include_directories('include'),
 362      dependencies : _deps,
 363      version : '6.0.0',
 364    )
 365
 366    has_rtti = false
 367    irbuilder_h = files('include/llvm/IR/IRBuilder.h')
 368
 369 It is very important that version is defined and is accurate, if it is
 370 not, workarounds for the wrong version of LLVM might be used resulting
 371 in build failures.
 372
 373 ``PKG_CONFIG_PATH``
 374 ^^^^^^^^^^^^^^^^^^^
 375
 376 The ``pkg-config`` utility is a hard requirement for configuring and
 377 building Mesa on Unix-like systems. It is used to search for external
 378 libraries on the system. This environment variable is used to control
 379 the search path for ``pkg-config``. For instance, setting
 380 ``PKG_CONFIG_PATH=/usr/X11R6/lib/pkgconfig`` will search for package
 381 metadata in ``/usr/X11R6`` before the standard directories.
 382
 383 Options
 384 ^^^^^^^
 385
 386 One of the oddities of meson is that some options are different when
 387 passed to the ``meson`` than to ``meson configure``. These options are
 388 passed as --option=foo to ``meson``, but -Doption=foo to
 389 ``meson configure``. Mesa defined options are always passed as
 390 -Doption=foo.
 391
 392 For those coming from autotools be aware of the following:
 393
 394 ``--buildtype/-Dbuildtype``
 395    This option will set the compiler debug/optimisation levels to aid
 396    debugging the Mesa libraries.
 397
 398    Note that in meson this defaults to ``debugoptimized``, and not
 399    setting it to ``release`` will yield non-optimal performance and
 400    binary size. Not using ``debug`` may interfere with debugging as some
 401    code and validation will be optimized away.
 402
 403    For those wishing to pass their own optimization flags, use the
 404    ``plain`` buildtype, which causes meson to inject no additional
 405    compiler arguments, only those in the C/CXXFLAGS and those that mesa
 406    itself defines.
 407
 408 ``-Db_ndebug``
 409    This option controls assertions in meson projects. When set to
 410    ``false`` (the default) assertions are enabled, when set to true they
 411    are disabled. This is unrelated to the ``buildtype``; setting the
 412    latter to ``release`` will not turn off assertions.
 413
 414 4. Cross-compilation and 32-bit builds
 415 --------------------------------------
 416
 417 `Meson supports
 418 cross-compilation <https://mesonbuild.com/Cross-compilation.html>`__ by
 419 specifying a number of binary paths and settings in a file and passing
 420 this file to ``meson`` or ``meson configure`` with the ``--cross-file``
 421 parameter.
 422
 423 This file can live at any location, but you can use the bare filename
 424 (without the folder path) if you put it in $XDG_DATA_HOME/meson/cross or
 425 ~/.local/share/meson/cross
 426
 427 Below are a few example of cross files, but keep in mind that you will
 428 likely have to alter them for your system.
 429
 430 Those running on ArchLinux can use the AUR-maintained packages for some
 431 of those, as they'll have the right values for your system:
 432
 433 -  `meson-cross-x86-linux-gnu <https://aur.archlinux.org/packages/meson-cross-x86-linux-gnu>`__
 434 -  `meson-cross-aarch64-linux-gnu <https://aur.archlinux.org/packages/meson-cross-aarch64-linux-gnu>`__
 435
 436 32-bit build on x86 linux:
 437
 438 ::
 439
 440    [binaries]
 441    c = '/usr/bin/gcc'
 442    cpp = '/usr/bin/g++'
 443    ar = '/usr/bin/gcc-ar'
 444    strip = '/usr/bin/strip'
 445    pkgconfig = '/usr/bin/pkg-config-32'
 446    llvm-config = '/usr/bin/llvm-config32'
 447
 448    [properties]
 449    c_args = ['-m32']
 450    c_link_args = ['-m32']
 451    cpp_args = ['-m32']
 452    cpp_link_args = ['-m32']
 453
 454    [host_machine]
 455    system = 'linux'
 456    cpu_family = 'x86'
 457    cpu = 'i686'
 458    endian = 'little'
 459
 460 64-bit build on ARM linux:
 461
 462 ::
 463
 464    [binaries]
 465    c = '/usr/bin/aarch64-linux-gnu-gcc'
 466    cpp = '/usr/bin/aarch64-linux-gnu-g++'
 467    ar = '/usr/bin/aarch64-linux-gnu-gcc-ar'
 468    strip = '/usr/bin/aarch64-linux-gnu-strip'
 469    pkgconfig = '/usr/bin/aarch64-linux-gnu-pkg-config'
 470    exe_wrapper = '/usr/bin/qemu-aarch64-static'
 471
 472    [host_machine]
 473    system = 'linux'
 474    cpu_family = 'aarch64'
 475    cpu = 'aarch64'
 476    endian = 'little'
 477
 478 64-bit build on x86 windows:
 479
 480 ::
 481
 482    [binaries]
 483    c = '/usr/bin/x86_64-w64-mingw32-gcc'
 484    cpp = '/usr/bin/x86_64-w64-mingw32-g++'
 485    ar = '/usr/bin/x86_64-w64-mingw32-ar'
 486    strip = '/usr/bin/x86_64-w64-mingw32-strip'
 487    pkgconfig = '/usr/bin/x86_64-w64-mingw32-pkg-config'
 488    exe_wrapper = 'wine'
 489
 490    [host_machine]
 491    system = 'windows'
 492    cpu_family = 'x86_64'
 493    cpu = 'i686'
 494    endian = 'little'