scons/gallium.py

   1 """gallium
   2
   3 Frontend-tool for Gallium3D architecture.
   4
   5 """
   6
   7 #
   8 # Copyright 2008 VMware, Inc.
   9 # All Rights Reserved.
  10 #
  11 # Permission is hereby granted, free of charge, to any person obtaining a
  12 # copy of this software and associated documentation files (the
  13 # "Software"), to deal in the Software without restriction, including
  14 # without limitation the rights to use, copy, modify, merge, publish,
  15 # distribute, sub license, and/or sell copies of the Software, and to
  16 # permit persons to whom the Software is furnished to do so, subject to
  17 # the following conditions:
  18 #
  19 # The above copyright notice and this permission notice (including the
  20 # next paragraph) shall be included in all copies or substantial portions
  21 # of the Software.
  22 #
  23 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  24 # OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25 # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  26 # IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
  27 # ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  28 # TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  29 # SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  30 #
  31
  32
  33 import distutils.version
  34 import os
  35 import os.path
  36 import re
  37 import subprocess
  38 import platform as _platform
  39 import sys
  40 import tempfile
  41
  42 import SCons.Action
  43 import SCons.Builder
  44 import SCons.Scanner
  45
  46
  47 def symlink(target, source, env):
  48     target = str(target[0])
  49     source = str(source[0])
  50     if os.path.islink(target) or os.path.exists(target):
  51         os.remove(target)
  52     os.symlink(os.path.basename(source), target)
  53
  54 def install(env, source, subdir):
  55     target_dir = os.path.join(env.Dir('#.').srcnode().abspath, env['build_dir'], subdir)
  56     return env.Install(target_dir, source)
  57
  58 def install_program(env, source):
  59     return install(env, source, 'bin')
  60
  61 def install_shared_library(env, sources, version = ()):
  62     targets = []
  63     install_dir = os.path.join(env.Dir('#.').srcnode().abspath, env['build_dir'])
  64     version = tuple(map(str, version))
  65     if env['SHLIBSUFFIX'] == '.dll':
  66         dlls = env.FindIxes(sources, 'SHLIBPREFIX', 'SHLIBSUFFIX')
  67         targets += install(env, dlls, 'bin')
  68         libs = env.FindIxes(sources, 'LIBPREFIX', 'LIBSUFFIX')
  69         targets += install(env, libs, 'lib')
  70     else:
  71         for source in sources:
  72             target_dir =  os.path.join(install_dir, 'lib')
  73             target_name = '.'.join((str(source),) + version)
  74             last = env.InstallAs(os.path.join(target_dir, target_name), source)
  75             targets += last
  76             while len(version):
  77                 version = version[:-1]
  78                 target_name = '.'.join((str(source),) + version)
  79                 action = SCons.Action.Action(symlink, "  Symlinking $TARGET ...")
  80                 last = env.Command(os.path.join(target_dir, target_name), last, action)
  81                 targets += last
  82     return targets
  83
  84
  85 def createInstallMethods(env):
  86     env.AddMethod(install_program, 'InstallProgram')
  87     env.AddMethod(install_shared_library, 'InstallSharedLibrary')
  88
  89
  90 def num_jobs():
  91     try:
  92         return int(os.environ['NUMBER_OF_PROCESSORS'])
  93     except (ValueError, KeyError):
  94         pass
  95
  96     try:
  97         return os.sysconf('SC_NPROCESSORS_ONLN')
  98     except (ValueError, OSError, AttributeError):
  99         pass
 100
 101     try:
 102         return int(os.popen2("sysctl -n hw.ncpu")[1].read())
 103     except ValueError:
 104         pass
 105
 106     return 1
 107
 108
 109 def check_cc(env, cc, expr, cpp_opt = '-E'):
 110     # Invoke C-preprocessor to determine whether the specified expression is
 111     # true or not.
 112
 113     sys.stdout.write('Checking for %s ... ' % cc)
 114
 115     source = tempfile.NamedTemporaryFile(suffix='.c', delete=False)
 116     source.write('#if !(%s)\n#error\n#endif\n' % expr)
 117     source.close()
 118
 119     pipe = SCons.Action._subproc(env, [env['CC'], cpp_opt, source.name],
 120                                  stdin = 'devnull',
 121                                  stderr = 'devnull',
 122                                  stdout = 'devnull')
 123     result = pipe.wait() == 0
 124
 125     os.unlink(source.name)
 126
 127     sys.stdout.write(' %s\n' % ['no', 'yes'][int(bool(result))])
 128     return result
 129
 130
 131 def generate(env):
 132     """Common environment generation code"""
 133
 134     # Tell tools which machine to compile for
 135     env['TARGET_ARCH'] = env['machine']
 136     env['MSVS_ARCH'] = env['machine']
 137
 138     # Toolchain
 139     platform = env['platform']
 140     env.Tool(env['toolchain'])
 141
 142     # Allow override compiler and specify additional flags from environment
 143     if os.environ.has_key('CC'):
 144         env['CC'] = os.environ['CC']
 145         # Update CCVERSION to match
 146         pipe = SCons.Action._subproc(env, [env['CC'], '--version'],
 147                                      stdin = 'devnull',
 148                                      stderr = 'devnull',
 149                                      stdout = subprocess.PIPE)
 150         if pipe.wait() == 0:
 151             line = pipe.stdout.readline()
 152             match = re.search(r'[0-9]+(\.[0-9]+)+', line)
 153             if match:
 154                 env['CCVERSION'] = match.group(0)
 155     if os.environ.has_key('CFLAGS'):
 156         env['CCFLAGS'] += SCons.Util.CLVar(os.environ['CFLAGS'])
 157     if os.environ.has_key('CXX'):
 158         env['CXX'] = os.environ['CXX']
 159     if os.environ.has_key('CXXFLAGS'):
 160         env['CXXFLAGS'] += SCons.Util.CLVar(os.environ['CXXFLAGS'])
 161     if os.environ.has_key('LDFLAGS'):
 162         env['LINKFLAGS'] += SCons.Util.CLVar(os.environ['LDFLAGS'])
 163
 164     # Detect gcc/clang not by executable name, but through pre-defined macros
 165     # as autoconf does, to avoid drawing wrong conclusions when using tools
 166     # that overrice CC/CXX like scan-build.
 167     env['gcc'] = 0
 168     env['clang'] = 0
 169     env['msvc'] = 0
 170     if _platform.system() == 'Windows':
 171         env['msvc'] = check_cc(env, 'MSVC', 'defined(_MSC_VER)', '/E')
 172     if not env['msvc']:
 173         env['gcc'] = check_cc(env, 'GCC', 'defined(__GNUC__) && !defined(__clang__)')
 174         env['clang'] = check_cc(env, 'Clang', '__clang__')
 175     env['suncc'] = env['platform'] == 'sunos' and os.path.basename(env['CC']) == 'cc'
 176     env['icc'] = 'icc' == os.path.basename(env['CC'])
 177
 178     if env['msvc'] and env['toolchain'] == 'default' and env['machine'] == 'x86_64':
 179         # MSVC x64 support is broken in earlier versions of scons
 180         env.EnsurePythonVersion(2, 0)
 181
 182     # shortcuts
 183     machine = env['machine']
 184     platform = env['platform']
 185     x86 = env['machine'] == 'x86'
 186     ppc = env['machine'] == 'ppc'
 187     gcc_compat = env['gcc'] or env['clang']
 188     msvc = env['msvc']
 189     suncc = env['suncc']
 190     icc = env['icc']
 191
 192     # Determine whether we are cross compiling; in particular, whether we need
 193     # to compile code generators with a different compiler as the target code.
 194     host_platform = _platform.system().lower()
 195     if host_platform.startswith('cygwin'):
 196         host_platform = 'cygwin'
 197     host_machine = os.environ.get('PROCESSOR_ARCHITEW6432', os.environ.get('PROCESSOR_ARCHITECTURE', _platform.machine()))
 198     host_machine = {
 199         'x86': 'x86',
 200         'i386': 'x86',
 201         'i486': 'x86',
 202         'i586': 'x86',
 203         'i686': 'x86',
 204         'ppc' : 'ppc',
 205         'AMD64': 'x86_64',
 206         'x86_64': 'x86_64',
 207     }.get(host_machine, 'generic')
 208     env['crosscompile'] = platform != host_platform
 209     if machine == 'x86_64' and host_machine != 'x86_64':
 210         env['crosscompile'] = True
 211     env['hostonly'] = False
 212
 213     # Backwards compatability with the debug= profile= options
 214     if env['build'] == 'debug':
 215         if not env['debug']:
 216             print 'scons: warning: debug option is deprecated and will be removed eventually; use instead'
 217             print
 218             print ' scons build=release'
 219             print
 220             env['build'] = 'release'
 221         if env['profile']:
 222             print 'scons: warning: profile option is deprecated and will be removed eventually; use instead'
 223             print
 224             print ' scons build=profile'
 225             print
 226             env['build'] = 'profile'
 227     if False:
 228         # Enforce SConscripts to use the new build variable
 229         env.popitem('debug')
 230         env.popitem('profile')
 231     else:
 232         # Backwards portability with older sconscripts
 233         if env['build'] in ('debug', 'checked'):
 234             env['debug'] = True
 235             env['profile'] = False
 236         if env['build'] == 'profile':
 237             env['debug'] = False
 238             env['profile'] = True
 239         if env['build'] == 'release':
 240             env['debug'] = False
 241             env['profile'] = False
 242
 243     # Put build output in a separate dir, which depends on the current
 244     # configuration. See also http://www.scons.org/wiki/AdvancedBuildExample
 245     build_topdir = 'build'
 246     build_subdir = env['platform']
 247     if env['embedded']:
 248         build_subdir =  'embedded-' + build_subdir
 249     if env['machine'] != 'generic':
 250         build_subdir += '-' + env['machine']
 251     if env['build'] != 'release':
 252         build_subdir += '-' +  env['build']
 253     build_dir = os.path.join(build_topdir, build_subdir)
 254     # Place the .sconsign file in the build dir too, to avoid issues with
 255     # different scons versions building the same source file
 256     env['build_dir'] = build_dir
 257     env.SConsignFile(os.path.join(build_dir, '.sconsign'))
 258     if 'SCONS_CACHE_DIR' in os.environ:
 259         print 'scons: Using build cache in %s.' % (os.environ['SCONS_CACHE_DIR'],)
 260         env.CacheDir(os.environ['SCONS_CACHE_DIR'])
 261     env['CONFIGUREDIR'] = os.path.join(build_dir, 'conf')
 262     env['CONFIGURELOG'] = os.path.join(os.path.abspath(build_dir), 'config.log')
 263
 264     # Parallel build
 265     if env.GetOption('num_jobs') <= 1:
 266         env.SetOption('num_jobs', num_jobs())
 267
 268     env.Decider('MD5-timestamp')
 269     env.SetOption('max_drift', 60)
 270
 271     # C preprocessor options
 272     cppdefines = []
 273     if env['build'] in ('debug', 'checked'):
 274         cppdefines += ['DEBUG']
 275     else:
 276         cppdefines += ['NDEBUG']
 277     if env['build'] == 'profile':
 278         cppdefines += ['PROFILE']
 279     if env['platform'] in ('posix', 'linux', 'freebsd', 'darwin'):
 280         cppdefines += [
 281             '_POSIX_SOURCE',
 282             ('_POSIX_C_SOURCE', '199309L'),
 283             '_SVID_SOURCE',
 284             '_BSD_SOURCE',
 285             '_GNU_SOURCE',
 286             'HAVE_PTHREAD',
 287             'HAVE_POSIX_MEMALIGN',
 288         ]
 289         if env['platform'] == 'darwin':
 290             cppdefines += [
 291                 '_DARWIN_C_SOURCE',
 292                 'GLX_USE_APPLEGL',
 293                 'GLX_DIRECT_RENDERING',
 294             ]
 295         else:
 296             cppdefines += [
 297                 'GLX_DIRECT_RENDERING',
 298                 'GLX_INDIRECT_RENDERING',
 299             ]
 300         if env['platform'] in ('linux', 'freebsd'):
 301             cppdefines += ['HAVE_ALIAS']
 302         else:
 303             cppdefines += ['GLX_ALIAS_UNSUPPORTED']
 304     if env['platform'] == 'haiku':
 305         cppdefines += [
 306             'HAVE_PTHREAD',
 307             'HAVE_POSIX_MEMALIGN'
 308         ]
 309     if platform == 'windows':
 310         cppdefines += [
 311             'WIN32',
 312             '_WINDOWS',
 313             #'_UNICODE',
 314             #'UNICODE',
 315             # http://msdn.microsoft.com/en-us/library/aa383745.aspx
 316             ('_WIN32_WINNT', '0x0601'),
 317             ('WINVER', '0x0601'),
 318         ]
 319         if gcc_compat:
 320             cppdefines += [('__MSVCRT_VERSION__', '0x0700')]
 321         if msvc:
 322             cppdefines += [
 323                 'VC_EXTRALEAN',
 324                 '_USE_MATH_DEFINES',
 325                 '_CRT_SECURE_NO_WARNINGS',
 326                 '_CRT_SECURE_NO_DEPRECATE',
 327                 '_SCL_SECURE_NO_WARNINGS',
 328                 '_SCL_SECURE_NO_DEPRECATE',
 329                 '_ALLOW_KEYWORD_MACROS',
 330             ]
 331         if env['build'] in ('debug', 'checked'):
 332             cppdefines += ['_DEBUG']
 333     if platform == 'windows':
 334         cppdefines += ['PIPE_SUBSYSTEM_WINDOWS_USER']
 335     if env['embedded']:
 336         cppdefines += ['PIPE_SUBSYSTEM_EMBEDDED']
 337     if env['texture_float']:
 338         print 'warning: Floating-point textures enabled.'
 339         print 'warning: Please consult docs/patents.txt with your lawyer before building Mesa.'
 340         cppdefines += ['TEXTURE_FLOAT_ENABLED']
 341     env.Append(CPPDEFINES = cppdefines)
 342
 343     # C compiler options
 344     cflags = [] # C
 345     cxxflags = [] # C++
 346     ccflags = [] # C & C++
 347     if gcc_compat:
 348         ccversion = env['CCVERSION']
 349         if env['build'] == 'debug':
 350             ccflags += ['-O0']
 351         elif env['gcc'] and ccversion.startswith('4.2.'):
 352             # gcc 4.2.x optimizer is broken
 353             print "warning: gcc 4.2.x optimizer is broken -- disabling optimizations"
 354             ccflags += ['-O0']
 355         else:
 356             ccflags += ['-O3']
 357         if env['gcc']:
 358             # gcc's builtin memcmp is slower than glibc's
 359             # http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43052
 360             ccflags += ['-fno-builtin-memcmp']
 361         # Work around aliasing bugs - developers should comment this out
 362         ccflags += ['-fno-strict-aliasing']
 363         ccflags += ['-g']
 364         if env['build'] in ('checked', 'profile'):
 365             # See http://code.google.com/p/jrfonseca/wiki/Gprof2Dot#Which_options_should_I_pass_to_gcc_when_compiling_for_profiling?
 366             ccflags += [
 367                 '-fno-omit-frame-pointer',
 368             ]
 369             if env['gcc']:
 370                 ccflags += ['-fno-optimize-sibling-calls']
 371         if env['machine'] == 'x86':
 372             ccflags += [
 373                 '-m32',
 374                 #'-march=pentium4',
 375             ]
 376             if distutils.version.LooseVersion(ccversion) >= distutils.version.LooseVersion('4.2') \
 377                and (platform != 'windows' or env['build'] == 'debug' or True) \
 378                and platform != 'haiku':
 379                 # NOTE: We need to ensure stack is realigned given that we
 380                 # produce shared objects, and have no control over the stack
 381                 # alignment policy of the application. Therefore we need
 382                 # -mstackrealign ore -mincoming-stack-boundary=2.
 383                 #
 384                 # XXX: -O and -mstackrealign causes stack corruption on MinGW
 385                 #
 386                 # XXX: We could have SSE without -mstackrealign if we always used
 387                 # __attribute__((force_align_arg_pointer)), but that's not
 388                 # always the case.
 389                 ccflags += [
 390                     '-mstackrealign', # ensure stack is aligned
 391                     '-mmmx', '-msse', '-msse2', # enable SIMD intrinsics
 392                     #'-mfpmath=sse',
 393                 ]
 394             if platform in ['windows', 'darwin']:
 395                 # Workaround http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37216
 396                 ccflags += ['-fno-common']
 397             if platform in ['haiku']:
 398                 # Make optimizations compatible with Pentium or higher on Haiku
 399                 ccflags += [
 400                     '-mstackrealign', # ensure stack is aligned
 401                     '-march=i586', # Haiku target is Pentium
 402                     '-mtune=i686' # use i686 where we can
 403                 ]
 404         if env['machine'] == 'x86_64':
 405             ccflags += ['-m64']
 406             if platform == 'darwin':
 407                 ccflags += ['-fno-common']
 408         if env['platform'] not in ('cygwin', 'haiku', 'windows'):
 409             ccflags += ['-fvisibility=hidden']
 410         # See also:
 411         # - http://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html
 412         ccflags += [
 413             '-Wall',
 414             '-Wno-long-long',
 415             '-fmessage-length=0', # be nice to Eclipse
 416         ]
 417         cflags += [
 418             '-Wmissing-prototypes',
 419             '-std=gnu99',
 420         ]
 421         if distutils.version.LooseVersion(ccversion) >= distutils.version.LooseVersion('4.2'):
 422             ccflags += [
 423                 '-Wpointer-arith',
 424             ]
 425             cflags += [
 426                 '-Wdeclaration-after-statement',
 427             ]
 428     if icc:
 429         cflags += [
 430             '-std=gnu99',
 431         ]
 432     if msvc:
 433         # See also:
 434         # - http://msdn.microsoft.com/en-us/library/19z1t1wy.aspx
 435         # - cl /?
 436         if env['build'] == 'debug':
 437             ccflags += [
 438               '/Od', # disable optimizations
 439               '/Oi', # enable intrinsic functions
 440             ]
 441         else:
 442             if 'MSVC_VERSION' in env and distutils.version.LooseVersion(env['MSVC_VERSION']) < distutils.version.LooseVersion('11.0'):
 443                 print 'scons: warning: Visual Studio versions prior to 2012 are known to produce incorrect code when optimizations are enabled ( https://bugs.freedesktop.org/show_bug.cgi?id=58718 )'
 444             ccflags += [
 445                 '/O2', # optimize for speed
 446             ]
 447         if env['build'] == 'release':
 448             ccflags += [
 449                 '/GL', # enable whole program optimization
 450             ]
 451         else:
 452             ccflags += [
 453                 '/Oy-', # disable frame pointer omission
 454                 '/GL-', # disable whole program optimization
 455             ]
 456         ccflags += [
 457             '/W3', # warning level
 458             #'/Wp64', # enable 64 bit porting warnings
 459             '/wd4996', # disable deprecated POSIX name warnings
 460         ]
 461         if env['machine'] == 'x86':
 462             ccflags += [
 463                 #'/arch:SSE2', # use the SSE2 instructions
 464             ]
 465         if platform == 'windows':
 466             ccflags += [
 467                 # TODO
 468             ]
 469         # Automatic pdb generation
 470         # See http://scons.tigris.org/issues/show_bug.cgi?id=1656
 471         env.EnsureSConsVersion(0, 98, 0)
 472         env['PDB'] = '${TARGET.base}.pdb'
 473     env.Append(CCFLAGS = ccflags)
 474     env.Append(CFLAGS = cflags)
 475     env.Append(CXXFLAGS = cxxflags)
 476
 477     if env['platform'] == 'windows' and msvc:
 478         # Choose the appropriate MSVC CRT
 479         # http://msdn.microsoft.com/en-us/library/2kzt1wy3.aspx
 480         if env['build'] in ('debug', 'checked'):
 481             env.Append(CCFLAGS = ['/MTd'])
 482             env.Append(SHCCFLAGS = ['/LDd'])
 483         else:
 484             env.Append(CCFLAGS = ['/MT'])
 485             env.Append(SHCCFLAGS = ['/LD'])
 486
 487     # Static code analysis
 488     if env['analyze']:
 489         if env['msvc']:
 490             # http://msdn.microsoft.com/en-us/library/ms173498.aspx
 491             env.Append(CCFLAGS = [
 492                 '/analyze',
 493                 #'/analyze:log', '${TARGET.base}.xml',
 494             ])
 495         if env['clang']:
 496             # scan-build will produce more comprehensive output
 497             env.Append(CCFLAGS = ['--analyze'])
 498
 499     # Assembler options
 500     if gcc_compat:
 501         if env['machine'] == 'x86':
 502             env.Append(ASFLAGS = ['-m32'])
 503         if env['machine'] == 'x86_64':
 504             env.Append(ASFLAGS = ['-m64'])
 505
 506     # Linker options
 507     linkflags = []
 508     shlinkflags = []
 509     if gcc_compat:
 510         if env['machine'] == 'x86':
 511             linkflags += ['-m32']
 512         if env['machine'] == 'x86_64':
 513             linkflags += ['-m64']
 514         if env['platform'] not in ('darwin'):
 515             shlinkflags += [
 516                 '-Wl,-Bsymbolic',
 517             ]
 518         # Handle circular dependencies in the libraries
 519         if env['platform'] in ('darwin'):
 520             pass
 521         else:
 522             env['_LIBFLAGS'] = '-Wl,--start-group ' + env['_LIBFLAGS'] + ' -Wl,--end-group'
 523         if env['platform'] == 'windows':
 524             # Avoid depending on gcc runtime DLLs
 525             linkflags += ['-static-libgcc']
 526             if 'w64' in env['CC'].split('-'):
 527                 linkflags += ['-static-libstdc++']
 528             # Handle the @xx symbol munging of DLL exports
 529             shlinkflags += ['-Wl,--enable-stdcall-fixup']
 530             #shlinkflags += ['-Wl,--kill-at']
 531     if msvc:
 532         if env['build'] == 'release':
 533             # enable Link-time Code Generation
 534             linkflags += ['/LTCG']
 535             env.Append(ARFLAGS = ['/LTCG'])
 536     if platform == 'windows' and msvc:
 537         # See also:
 538         # - http://msdn2.microsoft.com/en-us/library/y0zzbyt4.aspx
 539         linkflags += [
 540             '/fixed:no',
 541             '/incremental:no',
 542         ]
 543     env.Append(LINKFLAGS = linkflags)
 544     env.Append(SHLINKFLAGS = shlinkflags)
 545
 546     # We have C++ in several libraries, so always link with the C++ compiler
 547     if gcc_compat:
 548         env['LINK'] = env['CXX']
 549
 550     # Default libs
 551     libs = []
 552     if env['platform'] in ('darwin', 'freebsd', 'linux', 'posix', 'sunos'):
 553         libs += ['m', 'pthread', 'dl']
 554     if env['platform'] in ('linux',):
 555         libs += ['rt']
 556     if env['platform'] in ('haiku'):
 557         libs += ['root', 'be', 'network', 'translation']
 558     env.Append(LIBS = libs)
 559
 560     # OpenMP
 561     if env['openmp']:
 562         if env['msvc']:
 563             env.Append(CCFLAGS = ['/openmp'])
 564             # When building openmp release VS2008 link.exe crashes with LNK1103 error.
 565             # Workaround: overwrite PDB flags with empty value as it isn't required anyways
 566             if env['build'] == 'release':
 567                 env['PDB'] = ''
 568         if env['gcc']:
 569             env.Append(CCFLAGS = ['-fopenmp'])
 570             env.Append(LIBS = ['gomp'])
 571
 572     # Load tools
 573     env.Tool('lex')
 574     env.Tool('yacc')
 575     if env['llvm']:
 576         env.Tool('llvm')
 577
 578     # Custom builders and methods
 579     env.Tool('custom')
 580     createInstallMethods(env)
 581
 582     env.PkgCheckModules('X11', ['x11', 'xext', 'xdamage', 'xfixes'])
 583     env.PkgCheckModules('XCB', ['x11-xcb', 'xcb-glx >= 1.8.1'])
 584     env.PkgCheckModules('XF86VIDMODE', ['xxf86vm'])
 585     env.PkgCheckModules('DRM', ['libdrm >= 2.4.38'])
 586     env.PkgCheckModules('DRM_INTEL', ['libdrm_intel >= 2.4.52'])
 587     env.PkgCheckModules('UDEV', ['libudev >= 151'])
 588
 589     env['dri'] = env['x11'] and env['drm']
 590
 591     # for debugging
 592     #print env.Dump()
 593
 594
 595 def exists(env):
 596     return 1