mesa +osmesa

After investigating this for Alexander and comparing with my local build, I'm wondering if mesa +osmesa can resolve #52 (closed). I'm going to put this MR here so I can see if it starts building llvm, which we don't want...

spack/packages/mesa/package.py

-# Copyright 2013-2021 Lawrence Livermore National Security, LLC and other
-# Spack Project Developers. See the top-level COPYRIGHT file for details.
-#
-# SPDX-License-Identifier: (Apache-2.0 OR MIT)
-
-import sys
-
-from spack import *
-
-
-class Mesa(MesonPackage):
-    """Mesa is an open-source implementation of the OpenGL specification
-     - a system for rendering interactive 3D graphics."""
-
-    homepage = "http://www.mesa3d.org"
-    maintainers = ['chuckatkins', 'v-dobrev']
-
-    git = "https://gitlab.freedesktop.org/mesa/mesa.git"
-    url = "https://archive.mesa3d.org/mesa-20.2.1.tar.xz"
-
-    version('master', tag='master')
-    version('21.0.3', sha256='565c6f4bd2d5747b919454fc1d439963024fc78ca56fd05158c3b2cde2f6912b')
-    version('21.0.0', sha256='e6204e98e6a8d77cf9dc5d34f99dd8e3ef7144f3601c808ca0dd26ba522e0d84')
-    version('20.3.4', sha256='dc21a987ec1ff45b278fe4b1419b1719f1968debbb80221480e44180849b4084')
-    version('20.2.1', sha256='d1a46d9a3f291bc0e0374600bdcb59844fa3eafaa50398e472a36fc65fd0244a')
-
-    depends_on('meson@0.52:', type='build')
-
-    depends_on('pkgconfig', type='build')
-    depends_on('bison', type='build')
-    depends_on('cmake', type='build')
-    depends_on('flex', type='build')
-    depends_on('gettext', type='build')
-    depends_on('python@3:', type='build')
-    depends_on('py-mako@0.8.0:', type='build')
-    depends_on('expat')
-    depends_on('zlib@1.2.3:')
-
-    # Internal options
-    variant('llvm', default=True, description="Enable LLVM.")
-    variant('swr', default='auto',
-            values=('auto', 'none', 'avx', 'avx2', 'knl', 'skx'),
-            multi=True,
-            description="Enable the SWR driver.")
-    # conflicts('~llvm', when='~swr=none')
-
-    # Front ends
-    variant('osmesa', default=True, description="Enable the OSMesa frontend.")
-
-    is_linux = sys.platform.startswith('linux')
-    variant('glx', default=is_linux, description="Enable the GLX frontend.")
-
-    # TODO: effectively deal with EGL.  The implications of this have not been
-    # worked through yet
-    # variant('egl', default=False, description="Enable the EGL frontend.")
-
-    # TODO: Effectively deal with hardware drivers
-    # The implication of this is enabling DRI, among other things, and
-    # needing to check which llvm targets were built (ptx or amdgpu, etc.)
-
-    # Back ends
-    variant('opengl', default=True, description="Enable full OpenGL support.")
-    variant('opengles', default=False, description="Enable OpenGL ES support.")
-
-    # Provides
-    provides('gl@4.5',  when='+opengl')
-    provides('glx@1.4', when='+glx')
-    # provides('egl@1.5', when='+egl')
-    provides('osmesa', when='+osmesa')
-
-    # Variant dependencies
-    depends_on('llvm@6:', when='+llvm')
-    depends_on('libx11',  when='+glx')
-    depends_on('libxcb',  when='+glx')
-    depends_on('libxext', when='+glx')
-    depends_on('libxt',  when='+glx')
-    depends_on('xrandr', when='+glx')
-    depends_on('glproto@1.4.14:', when='+glx')
-
-    # version specific issue
-    # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96130
-    conflicts('%gcc@10.1.0', msg='GCC 10.1.0 has a bug')
-
-    # Require at least 1 front-end
-    # TODO: Add egl to this conflict once made available
-    conflicts('~osmesa ~glx')
-
-    # Require at least 1 back-end
-    # TODO: Add vulkan to this conflict once made available
-    conflicts('~opengl ~opengles')
-
-    # OpenGL ES requires OpenGL
-    conflicts('~opengl +opengles')
-
-    # requires native to be added to llvm_modules when using gallium swrast
-    patch('https://cgit.freedesktop.org/mesa/mesa/patch/meson.build?id=054dd668a69acc70d47c73abe4646e96a1f23577', sha256='36096a178070e40217945e12d542dfe80016cb897284a01114d616656c577d73', when='@21.0.0:21.0.3')
-
-    # 'auto' needed when shared llvm is built
-    @when('^llvm~shared_libs')
-    def patch(self):
-        filter_file(
-            r"_llvm_method = 'auto'",
-            "_llvm_method = 'config-tool'",
-            "meson.build")
-
-    def meson_args(self):
-        spec = self.spec
-        args = [
-            '-Dvulkan-drivers=',
-            '-Dgallium-vdpau=disabled',
-            '-Dgallium-xvmc=disabled',
-            '-Dgallium-omx=disabled',
-            '-Dgallium-va=disabled',
-            '-Dgallium-xa=disabled',
-            '-Dgallium-nine=false',
-            '-Dgallium-opencl=disabled',
-            '-Dbuild-tests=false',
-            '-Dglvnd=false']
-        args_platforms = []
-        args_gallium_drivers = ['swrast']
-        args_dri_drivers = []
-
-        opt_enable = lambda c, o: '-D%s=%sabled' % (o, 'en' if c else 'dis')
-        opt_bool = lambda c, o: '-D%s=%s' % (o, str(c).lower())
-        if spec.target.family == 'arm' or spec.target.family == 'aarch64':
-            args.append('-Dlibunwind=disabled')
-
-        num_frontends = 0
-
-        if spec.satisfies('@:20.3'):
-            osmesa_enable, osmesa_disable = ('gallium', 'none')
-        else:
-            osmesa_enable, osmesa_disable = ('true', 'false')
-
-        if '+osmesa' in spec:
-            num_frontends += 1
-            args.append('-Dosmesa={0}'.format(osmesa_enable))
-        else:
-            args.append('-Dosmesa={0}'.format(osmesa_disable))
-
-        if '+glx' in spec:
-            num_frontends += 1
-            if '+egl' in spec:
-                args.append('-Dglx=dri')
-            else:
-                args.append('-Dglx=gallium-xlib')
-            args_platforms.append('x11')
-        else:
-            args.append('-Dglx=disabled')
-
-        if '+egl' in spec:
-            num_frontends += 1
-            args.extend(['-Degl=enabled', '-Dgbm=enabled', '-Ddri3=enabled'])
-            args_platforms.append('surfaceless')
-        else:
-            args.extend(
-                ['-Degl=disabled', '-Dgbm=disabled', '-Ddri3=disabled'])
-
-        args.append(opt_bool('+opengl' in spec, 'opengl'))
-        args.append(opt_enable('+opengles' in spec, 'gles1'))
-        args.append(opt_enable('+opengles' in spec, 'gles2'))
-
-        args.append(opt_enable(num_frontends > 1, 'shared-glapi'))
-
-        if '+llvm' in spec:
-            args.append('-Dllvm=enabled')
-            args.append(opt_enable(
-                '+link_dylib' in spec['llvm'], 'shared-llvm'))
-        else:
-            args.append('-Dllvm=disabled')
-
-        args_swr_arches = []
-        if 'swr=auto' in spec:
-            if 'avx' in spec.target:
-                args_swr_arches.append('avx')
-            if 'avx2' in spec.target:
-                args_swr_arches.append('avx2')
-            if 'avx512f' in spec.target:
-                if 'avx512er' in spec.target:
-                    args_swr_arches.append('knl')
-                if 'avx512bw' in spec.target:
-                    args_swr_arches.append('skx')
-        else:
-            if 'swr=avx' in spec:
-                args_swr_arches.append('avx')
-            if 'swr=avx2' in spec:
-                args_swr_arches.append('avx2')
-            if 'swr=knl' in spec:
-                args_swr_arches.append('knl')
-            if 'swr=skx' in spec:
-                args_swr_arches.append('skx')
-
-        if args_swr_arches:
-            if '+llvm' not in spec:
-                raise SpecError('Variant swr requires +llvm')
-            args_gallium_drivers.append('swr')
-            args.append('-Dswr-arches=' + ','.join(args_swr_arches))
-
-        # Add the remaining list args
-        args.append('-Dplatforms=' + ','.join(args_platforms))
-        args.append('-Dgallium-drivers=' + ','.join(args_gallium_drivers))
-        args.append('-Ddri-drivers=' + ','.join(args_dri_drivers))
-
-        return args
-
-    @property
-    def libs(self):
-        spec = self.spec
-        libs_to_seek = set()
-
-        if '+osmesa' in spec:
-            libs_to_seek.add('libOSMesa')
-
-        if '+glx' in spec:
-            libs_to_seek.add('libGL')
-
-        if '+opengl' in spec:
-            libs_to_seek.add('libGL')
-
-        if '+opengles' in spec:
-            libs_to_seek.add('libGLES')
-            libs_to_seek.add('libGLES2')
-
-        if libs_to_seek:
-            return find_libraries(list(libs_to_seek),
-                                  root=self.spec.prefix,
-                                  recursive=True)
-        return LibraryList()
-
-    @property
-    def osmesa_libs(self):
-        return find_libraries('libOSMesa',
-                              root=self.spec.prefix,
-                              recursive=True)
-
-    @property
-    def glx_libs(self):
-        return find_libraries('libGL',
-                              root=self.spec.prefix,
-                              recursive=True)
-
-    @property
-    def gl_libs(self):
-        return find_libraries('libGL',
-                              root=self.spec.prefix,
-                              recursive=True)