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 Windows specific instructions
 145 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 146
 147 On windows you have a couple of choices for compilers. If you installed
 148 mingw with chocolatey and want to use ninja you should be able to open
 149 any shell and follow the instructions above. If you want to you MSVC,
 150 clang-cl, or ICL (the Intel Compiler), read on.
 151
 152 Both ICL and MSVC come with shell environments, the easiest way to use
 153 meson with these it to open a shell. For clang-cl you will need to open
 154 an MSVC shell, and then override the compilers, either using a `native
 155 file <https://mesonbuild.com/Native-environments.html>`__, or with the
 156 CC and CXX environment variables.
 157
 158 All of these compilers are tested and work with ninja, but if you want
 159 visual studio integration or you just like msbuild, passing
 160 ``--backend=vs`` to meson will generate a visual studio solution. If you
 161 want to use ICL or clang-cl with the vsbackend you will need meson
 162 0.52.0 or greater. Older versions always use the microsoft compiler.
 163
 164 3. Advanced Usage
 165 -----------------
 166
 167 Installation Location
 168 ^^^^^^^^^^^^^^^^^^^^^
 169
 170 Meson default to installing libGL.so in your system's main lib/
 171 directory and DRI drivers to a dri/ subdirectory.
 172
 173 Developers will often want to install Mesa to a testing directory rather
 174 than the system library directory. This can be done with the --prefix
 175 option. For example:
 176
 177 .. code-block:: console
 178
 179    meson --prefix="${PWD}/build/install" build/
 180
 181 will put the final libraries and drivers into the build/install/
 182 directory. Then you can set LD_LIBRARY_PATH and LIBGL_DRIVERS_PATH to
 183 that location to run/test the driver.
 184
 185 Meson also honors ``DESTDIR`` for installs.
 186
 187 Compiler Options
 188 ^^^^^^^^^^^^^^^^
 189
 190 Meson supports the common CFLAGS, CXXFLAGS, etc. environment variables
 191 but their use is discouraged because of the many caveats in using them.
 192
 193 Instead, it is recomended to use ``-D${lang}_args`` and
 194 ``-D${lang}_link_args``. Among the benefits of these options is that
 195 they are guaranteed to persist across rebuilds and reconfigurations.
 196
 197 This example sets -fmax-errors for compiling C sources and -DMAGIC=123
 198 for C++ sources:
 199
 200 .. code-block:: console
 201
 202    meson builddir/ -Dc_args=-fmax-errors=10 -Dcpp_args=-DMAGIC=123
 203
 204 Compiler Specification
 205 ^^^^^^^^^^^^^^^^^^^^^^
 206
 207 Meson supports the standard CC and CXX environment variables for
 208 changing the default compiler. Note that Meson does not allow changing
 209 the compilers in a configured builddir so you will need to create a new
 210 build dir for a different compiler.
 211
 212 This is an example of specifying the clang compilers and cleaning the
 213 build directory before reconfiguring with an extra C option:
 214
 215 .. code-block:: console
 216
 217    CC=clang CXX=clang++ meson build-clang
 218    ninja -C build-clang
 219    ninja -C build-clang clean
 220    meson configure build -Dc_args="-Wno-typedef-redefinition"
 221    ninja -C build-clang
 222
 223 The default compilers depends on your operating system. Meson supports
 224 most of the popular compilers, a complete list is available
 225 `here <https://mesonbuild.com/Reference-tables.html#compiler-ids>`__.
 226
 227 LLVM
 228 ^^^^
 229
 230 Meson includes upstream logic to wrap llvm-config using its standard
 231 dependency interface.
 232
 233 As of meson 0.51.0 meson can use cmake to find llvm (the cmake finder
 234 was added in meson 0.49.0, but LLVM cannot be found until 0.51) Due to
 235 the way LLVM implements its cmake finder it will only find static
 236 libraries, it will never find libllvm.so. There is also a
 237 ``-Dcmake_module_path`` option in this meson version, which points to
 238 the root of an alternative installation (the prefix). For example:
 239
 240 .. code-block:: console
 241
 242    meson builddir -Dcmake_module_path=/home/user/mycmake/prefix
 243
 244 As of meson 0.49.0 meson also has the concept of a `"native
 245 file" <https://mesonbuild.com/Native-environments.html>`__, these files
 246 provide information about the native build environment (as opposed to a
 247 cross build environment). They are ini formatted and can override where
 248 to find llvm-config:
 249
 250 custom-llvm.ini
 251
 252 ::
 253
 254    [binaries]
 255    llvm-config = '/usr/local/bin/llvm/llvm-config'
 256
 257 Then configure meson:
 258
 259 .. code-block:: console
 260
 261    meson builddir/ --native-file custom-llvm.ini
 262
 263 Meson < 0.49 doesn't support native files, so to specify a custom
 264 ``llvm-config`` you need to modify your ``$PATH`` (or ``%PATH%`` on
 265 windows), which will be searched for ``llvm-config``,
 266 ``llvm-config$version``, and ``llvm-config-$version``:
 267
 268 .. code-block:: console
 269
 270    PATH=/path/to/folder/with/llvm-config:$PATH meson build
 271
 272 For selecting llvm-config for cross compiling a `"cross
 273 file" <https://mesonbuild.com/Cross-compilation.html#defining-the-environment>`__
 274 should be used. It uses the same format as the native file above:
 275
 276 cross-llvm.ini
 277
 278 ::
 279
 280    [binaries]
 281    ...
 282    llvm-config = '/usr/lib/llvm-config-32'
 283    cmake = '/usr/bin/cmake-for-my-arch'
 284
 285 Obviously, only cmake or llvm-config is required.
 286
 287 Then configure meson:
 288
 289 .. code-block:: console
 290
 291    meson builddir/ --cross-file cross-llvm.ini
 292
 293 See the :ref:`Cross Compilation <cross-compilation>` section for more
 294 information.
 295
 296 On windows (and in other cases), using llvm-config or cmake may be
 297 either undesirable or impossible. Meson's solution for this is a
 298 `wrap <https://mesonbuild.com/Wrap-dependency-system-manual.html>`__, in
 299 this case a "binary wrap". Follow the steps below:
 300
 301 -  Install the binaries and headers into the
 302    ``$mesa_src/subprojects/llvm``
 303 -  Add a meson build.build file to that directory (more on that later)
 304
 305 The wrap file must define the following:
 306
 307 -  ``dep_llvm``: a ``declare_dependency()`` object with
 308    include_directories, dependencies, and version set)
 309
 310 It may also define:
 311
 312 -  ``irbuilder_h``: a ``files()`` object pointing to llvm/IR/IRBuilder.h
 313    (this is requred for SWR)
 314 -  ``has_rtti``: a ``bool`` that declares whether LLVM was built with
 315    RTTI. Defaults to true
 316
 317 such a meson.build file might look like:
 318
 319 ::
 320
 321    project('llvm', ['cpp'])
 322
 323    cpp = meson.get_compiler('cpp')
 324
 325    _deps = []
 326    _search = join_paths(meson.current_source_dir(), 'lib')
 327    foreach d : ['libLLVMCodeGen', 'libLLVMScalarOpts', 'libLLVMAnalysis',
 328                 'libLLVMTransformUtils', 'libLLVMCore', 'libLLVMX86CodeGen',
 329                 'libLLVMSelectionDAG', 'libLLVMipo', 'libLLVMAsmPrinter',
 330                 'libLLVMInstCombine', 'libLLVMInstrumentation', 'libLLVMMC',
 331                 'libLLVMGlobalISel', 'libLLVMObjectYAML', 'libLLVMDebugInfoPDB',
 332                 'libLLVMVectorize', 'libLLVMPasses', 'libLLVMSupport',
 333                 'libLLVMLTO', 'libLLVMObject', 'libLLVMDebugInfoCodeView',
 334                 'libLLVMDebugInfoDWARF', 'libLLVMOrcJIT', 'libLLVMProfileData',
 335                 'libLLVMObjCARCOpts', 'libLLVMBitReader', 'libLLVMCoroutines',
 336                 'libLLVMBitWriter', 'libLLVMRuntimeDyld', 'libLLVMMIRParser',
 337                 'libLLVMX86Desc', 'libLLVMAsmParser', 'libLLVMTableGen',
 338                 'libLLVMFuzzMutate', 'libLLVMLinker', 'libLLVMMCParser',
 339                 'libLLVMExecutionEngine', 'libLLVMCoverage', 'libLLVMInterpreter',
 340                 'libLLVMTarget', 'libLLVMX86AsmParser', 'libLLVMSymbolize',
 341                 'libLLVMDebugInfoMSF', 'libLLVMMCJIT', 'libLLVMXRay',
 342                 'libLLVMX86AsmPrinter', 'libLLVMX86Disassembler',
 343                 'libLLVMMCDisassembler', 'libLLVMOption', 'libLLVMIRReader',
 344                 'libLLVMLibDriver', 'libLLVMDlltoolDriver', 'libLLVMDemangle',
 345                 'libLLVMBinaryFormat', 'libLLVMLineEditor',
 346                 'libLLVMWindowsManifest', 'libLLVMX86Info', 'libLLVMX86Utils']
 347      _deps += cpp.find_library(d, dirs : _search)
 348    endforeach
 349
 350    dep_llvm = declare_dependency(
 351      include_directories : include_directories('include'),
 352      dependencies : _deps,
 353      version : '6.0.0',
 354    )
 355
 356    has_rtti = false
 357    irbuilder_h = files('include/llvm/IR/IRBuilder.h')
 358
 359 It is very important that version is defined and is accurate, if it is
 360 not, workarounds for the wrong version of LLVM might be used resulting
 361 in build failures.
 362
 363 ``PKG_CONFIG_PATH``
 364 ^^^^^^^^^^^^^^^^^^^
 365
 366 The ``pkg-config`` utility is a hard requirement for configuring and
 367 building Mesa on Unix-like systems. It is used to search for external
 368 libraries on the system. This environment variable is used to control
 369 the search path for ``pkg-config``. For instance, setting
 370 ``PKG_CONFIG_PATH=/usr/X11R6/lib/pkgconfig`` will search for package
 371 metadata in ``/usr/X11R6`` before the standard directories.
 372
 373 Options
 374 ^^^^^^^
 375
 376 One of the oddities of meson is that some options are different when
 377 passed to the ``meson`` than to ``meson configure``. These options are
 378 passed as --option=foo to ``meson``, but -Doption=foo to
 379 ``meson configure``. Mesa defined options are always passed as
 380 -Doption=foo.
 381
 382 For those coming from autotools be aware of the following:
 383
 384 ``--buildtype/-Dbuildtype``
 385    This option will set the compiler debug/optimisation levels to aid
 386    debugging the Mesa libraries.
 387
 388    Note that in meson this defaults to ``debugoptimized``, and not
 389    setting it to ``release`` will yield non-optimal performance and
 390    binary size. Not using ``debug`` may interfere with debugging as some
 391    code and validation will be optimized away.
 392
 393    For those wishing to pass their own optimization flags, use the
 394    ``plain`` buildtype, which causes meson to inject no additional
 395    compiler arguments, only those in the C/CXXFLAGS and those that mesa
 396    itself defines.
 397
 398 ``-Db_ndebug``
 399    This option controls assertions in meson projects. When set to
 400    ``false`` (the default) assertions are enabled, when set to true they
 401    are disabled. This is unrelated to the ``buildtype``; setting the
 402    latter to ``release`` will not turn off assertions.
 403
 404 .. _cross-compilation:
 405
 406 4. Cross-compilation and 32-bit builds
 407 --------------------------------------
 408
 409 `Meson supports
 410 cross-compilation <https://mesonbuild.com/Cross-compilation.html>`__ by
 411 specifying a number of binary paths and settings in a file and passing
 412 this file to ``meson`` or ``meson configure`` with the ``--cross-file``
 413 parameter.
 414
 415 This file can live at any location, but you can use the bare filename
 416 (without the folder path) if you put it in $XDG_DATA_HOME/meson/cross or
 417 ~/.local/share/meson/cross
 418
 419 Below are a few example of cross files, but keep in mind that you will
 420 likely have to alter them for your system.
 421
 422 Those running on ArchLinux can use the AUR-maintained packages for some
 423 of those, as they'll have the right values for your system:
 424
 425 -  `meson-cross-x86-linux-gnu <https://aur.archlinux.org/packages/meson-cross-x86-linux-gnu>`__
 426 -  `meson-cross-aarch64-linux-gnu <https://aur.archlinux.org/packages/meson-cross-aarch64-linux-gnu>`__
 427
 428 32-bit build on x86 linux:
 429
 430 ::
 431
 432    [binaries]
 433    c = '/usr/bin/gcc'
 434    cpp = '/usr/bin/g++'
 435    ar = '/usr/bin/gcc-ar'
 436    strip = '/usr/bin/strip'
 437    pkgconfig = '/usr/bin/pkg-config-32'
 438    llvm-config = '/usr/bin/llvm-config32'
 439
 440    [properties]
 441    c_args = ['-m32']
 442    c_link_args = ['-m32']
 443    cpp_args = ['-m32']
 444    cpp_link_args = ['-m32']
 445
 446    [host_machine]
 447    system = 'linux'
 448    cpu_family = 'x86'
 449    cpu = 'i686'
 450    endian = 'little'
 451
 452 64-bit build on ARM linux:
 453
 454 ::
 455
 456    [binaries]
 457    c = '/usr/bin/aarch64-linux-gnu-gcc'
 458    cpp = '/usr/bin/aarch64-linux-gnu-g++'
 459    ar = '/usr/bin/aarch64-linux-gnu-gcc-ar'
 460    strip = '/usr/bin/aarch64-linux-gnu-strip'
 461    pkgconfig = '/usr/bin/aarch64-linux-gnu-pkg-config'
 462    exe_wrapper = '/usr/bin/qemu-aarch64-static'
 463
 464    [host_machine]
 465    system = 'linux'
 466    cpu_family = 'aarch64'
 467    cpu = 'aarch64'
 468    endian = 'little'
 469
 470 64-bit build on x86 windows:
 471
 472 ::
 473
 474    [binaries]
 475    c = '/usr/bin/x86_64-w64-mingw32-gcc'
 476    cpp = '/usr/bin/x86_64-w64-mingw32-g++'
 477    ar = '/usr/bin/x86_64-w64-mingw32-ar'
 478    strip = '/usr/bin/x86_64-w64-mingw32-strip'
 479    pkgconfig = '/usr/bin/x86_64-w64-mingw32-pkg-config'
 480    exe_wrapper = 'wine'
 481
 482    [host_machine]
 483    system = 'windows'
 484    cpu_family = 'x86_64'
 485    cpu = 'i686'
 486    endian = 'little'