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 host_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 msvc2013_compat(env):
  86     if env['gcc']:
  87         env.Append(CCFLAGS = [
  88             '-Werror=vla',
  89             '-Werror=pointer-arith',
  90         ])
  91
  92
  93 def unit_test(env, test_name, program_target, args=None):
  94     env.InstallProgram(program_target)
  95
  96     cmd = [program_target[0].abspath]
  97     if args is not None:
  98         cmd += args
  99     cmd = ' '.join(cmd)
 100
 101     # http://www.scons.org/wiki/UnitTests
 102     action = SCons.Action.Action(cmd, "  Running $SOURCE ...")
 103     alias = env.Alias(test_name, program_target, action)
 104     env.AlwaysBuild(alias)
 105     env.Depends('check', alias)
 106
 107
 108 def num_jobs():
 109     try:
 110         return int(os.environ['NUMBER_OF_PROCESSORS'])
 111     except (ValueError, KeyError):
 112         pass
 113
 114     try:
 115         return os.sysconf('SC_NPROCESSORS_ONLN')
 116     except (ValueError, OSError, AttributeError):
 117         pass
 118
 119     try:
 120         return int(os.popen2("sysctl -n hw.ncpu")[1].read())
 121     except ValueError:
 122         pass
 123
 124     return 1
 125
 126
 127 def check_cc(env, cc, expr, cpp_opt = '-E'):
 128     # Invoke C-preprocessor to determine whether the specified expression is
 129     # true or not.
 130
 131     sys.stdout.write('Checking for %s ... ' % cc)
 132
 133     source = tempfile.NamedTemporaryFile(suffix='.c', delete=False)
 134     source.write('#if !(%s)\n#error\n#endif\n' % expr)
 135     source.close()
 136
 137     pipe = SCons.Action._subproc(env, [env['CC'], cpp_opt, source.name],
 138                                  stdin = 'devnull',
 139                                  stderr = 'devnull',
 140                                  stdout = 'devnull')
 141     result = pipe.wait() == 0
 142
 143     os.unlink(source.name)
 144
 145     sys.stdout.write(' %s\n' % ['no', 'yes'][int(bool(result))])
 146     return result
 147
 148
 149 def check_prog(env, prog):
 150     """Check whether this program exists."""
 151
 152     sys.stdout.write('Checking for %s ... ' % prog)
 153
 154     result = env.Detect(prog)
 155
 156     sys.stdout.write(' %s\n' % ['no', 'yes'][int(bool(result))])
 157     return result
 158
 159
 160 def generate(env):
 161     """Common environment generation code"""
 162
 163     # Tell tools which machine to compile for
 164     env['TARGET_ARCH'] = env['machine']
 165     env['MSVS_ARCH'] = env['machine']
 166
 167     # Toolchain
 168     platform = env['platform']
 169     env.Tool(env['toolchain'])
 170
 171     # Allow override compiler and specify additional flags from environment
 172     if os.environ.has_key('CC'):
 173         env['CC'] = os.environ['CC']
 174     if os.environ.has_key('CFLAGS'):
 175         env['CCFLAGS'] += SCons.Util.CLVar(os.environ['CFLAGS'])
 176     if os.environ.has_key('CXX'):
 177         env['CXX'] = os.environ['CXX']
 178     if os.environ.has_key('CXXFLAGS'):
 179         env['CXXFLAGS'] += SCons.Util.CLVar(os.environ['CXXFLAGS'])
 180     if os.environ.has_key('LDFLAGS'):
 181         env['LINKFLAGS'] += SCons.Util.CLVar(os.environ['LDFLAGS'])
 182
 183     # Detect gcc/clang not by executable name, but through pre-defined macros
 184     # as autoconf does, to avoid drawing wrong conclusions when using tools
 185     # that overrice CC/CXX like scan-build.
 186     env['gcc_compat'] = 0
 187     env['clang'] = 0
 188     env['msvc'] = 0
 189     if host_platform.system() == 'Windows':
 190         env['msvc'] = check_cc(env, 'MSVC', 'defined(_MSC_VER)', '/E')
 191     if not env['msvc']:
 192         env['gcc_compat'] = check_cc(env, 'GCC', 'defined(__GNUC__)')
 193     env['clang'] = check_cc(env, 'Clang', '__clang__')
 194     env['gcc'] = env['gcc_compat'] and not env['clang']
 195     env['suncc'] = env['platform'] == 'sunos' and os.path.basename(env['CC']) == 'cc'
 196     env['icc'] = 'icc' == os.path.basename(env['CC'])
 197
 198     if env['msvc'] and env['toolchain'] == 'default' and env['machine'] == 'x86_64':
 199         # MSVC x64 support is broken in earlier versions of scons
 200         env.EnsurePythonVersion(2, 0)
 201
 202     # shortcuts
 203     machine = env['machine']
 204     platform = env['platform']
 205     x86 = env['machine'] == 'x86'
 206     ppc = env['machine'] == 'ppc'
 207     gcc_compat = env['gcc_compat']
 208     msvc = env['msvc']
 209     suncc = env['suncc']
 210     icc = env['icc']
 211
 212     # Determine whether we are cross compiling; in particular, whether we need
 213     # to compile code generators with a different compiler as the target code.
 214     hosthost_platform = host_platform.system().lower()
 215     if hosthost_platform.startswith('cygwin'):
 216         hosthost_platform = 'cygwin'
 217     host_machine = os.environ.get('PROCESSOR_ARCHITEW6432', os.environ.get('PROCESSOR_ARCHITECTURE', host_platform.machine()))
 218     host_machine = {
 219         'x86': 'x86',
 220         'i386': 'x86',
 221         'i486': 'x86',
 222         'i586': 'x86',
 223         'i686': 'x86',
 224         'ppc' : 'ppc',
 225         'AMD64': 'x86_64',
 226         'x86_64': 'x86_64',
 227     }.get(host_machine, 'generic')
 228     env['crosscompile'] = platform != hosthost_platform
 229     if machine == 'x86_64' and host_machine != 'x86_64':
 230         env['crosscompile'] = True
 231     env['hostonly'] = False
 232
 233     # Backwards compatability with the debug= profile= options
 234     if env['build'] == 'debug':
 235         if not env['debug']:
 236             print 'scons: warning: debug option is deprecated and will be removed eventually; use instead'
 237             print
 238             print ' scons build=release'
 239             print
 240             env['build'] = 'release'
 241         if env['profile']:
 242             print 'scons: warning: profile option is deprecated and will be removed eventually; use instead'
 243             print
 244             print ' scons build=profile'
 245             print
 246             env['build'] = 'profile'
 247     if False:
 248         # Enforce SConscripts to use the new build variable
 249         env.popitem('debug')
 250         env.popitem('profile')
 251     else:
 252         # Backwards portability with older sconscripts
 253         if env['build'] in ('debug', 'checked'):
 254             env['debug'] = True
 255             env['profile'] = False
 256         if env['build'] == 'profile':
 257             env['debug'] = False
 258             env['profile'] = True
 259         if env['build'] in ('release', 'opt'):
 260             env['debug'] = False
 261             env['profile'] = False
 262
 263     # Put build output in a separate dir, which depends on the current
 264     # configuration. See also http://www.scons.org/wiki/AdvancedBuildExample
 265     build_topdir = 'build'
 266     build_subdir = env['platform']
 267     if env['embedded']:
 268         build_subdir =  'embedded-' + build_subdir
 269     if env['machine'] != 'generic':
 270         build_subdir += '-' + env['machine']
 271     if env['build'] != 'release':
 272         build_subdir += '-' +  env['build']
 273     build_dir = os.path.join(build_topdir, build_subdir)
 274     # Place the .sconsign file in the build dir too, to avoid issues with
 275     # different scons versions building the same source file
 276     env['build_dir'] = build_dir
 277     env.SConsignFile(os.path.join(build_dir, '.sconsign'))
 278     if 'SCONS_CACHE_DIR' in os.environ:
 279         print 'scons: Using build cache in %s.' % (os.environ['SCONS_CACHE_DIR'],)
 280         env.CacheDir(os.environ['SCONS_CACHE_DIR'])
 281     env['CONFIGUREDIR'] = os.path.join(build_dir, 'conf')
 282     env['CONFIGURELOG'] = os.path.join(os.path.abspath(build_dir), 'config.log')
 283
 284     # Parallel build
 285     if env.GetOption('num_jobs') <= 1:
 286         env.SetOption('num_jobs', num_jobs())
 287
 288     env.Decider('MD5-timestamp')
 289     env.SetOption('max_drift', 60)
 290
 291     # C preprocessor options
 292     cppdefines = []
 293     cppdefines += [
 294         '__STDC_CONSTANT_MACROS',
 295         '__STDC_FORMAT_MACROS',
 296         '__STDC_LIMIT_MACROS',
 297         'HAVE_NO_AUTOCONF',
 298     ]
 299     if env['build'] in ('debug', 'checked'):
 300         cppdefines += ['DEBUG']
 301     else:
 302         cppdefines += ['NDEBUG']
 303     if env['build'] == 'profile':
 304         cppdefines += ['PROFILE']
 305     if env['build'] in ('opt', 'profile'):
 306         cppdefines += ['VMX86_STATS']
 307     if env['platform'] in ('posix', 'linux', 'freebsd', 'darwin'):
 308         cppdefines += [
 309             '_POSIX_SOURCE',
 310             ('_POSIX_C_SOURCE', '199309L'),
 311             '_SVID_SOURCE',
 312             '_BSD_SOURCE',
 313             '_GNU_SOURCE',
 314             '_DEFAULT_SOURCE',
 315         ]
 316         if env['platform'] == 'darwin':
 317             cppdefines += [
 318                 '_DARWIN_C_SOURCE',
 319                 'GLX_USE_APPLEGL',
 320                 'GLX_DIRECT_RENDERING',
 321             ]
 322         else:
 323             cppdefines += [
 324                 'GLX_DIRECT_RENDERING',
 325                 'GLX_INDIRECT_RENDERING',
 326             ]
 327
 328         conf = SCons.Script.Configure(env)
 329         if conf.CheckHeader('xlocale.h'):
 330             cppdefines += ['HAVE_XLOCALE_H']
 331         env = conf.Finish()
 332
 333     if platform == 'windows':
 334         cppdefines += [
 335             'WIN32',
 336             '_WINDOWS',
 337             #'_UNICODE',
 338             #'UNICODE',
 339             # http://msdn.microsoft.com/en-us/library/aa383745.aspx
 340             ('_WIN32_WINNT', '0x0601'),
 341             ('WINVER', '0x0601'),
 342         ]
 343         if gcc_compat:
 344             cppdefines += [('__MSVCRT_VERSION__', '0x0700')]
 345         if msvc:
 346             cppdefines += [
 347                 'VC_EXTRALEAN',
 348                 '_USE_MATH_DEFINES',
 349                 '_CRT_SECURE_NO_WARNINGS',
 350                 '_CRT_SECURE_NO_DEPRECATE',
 351                 '_SCL_SECURE_NO_WARNINGS',
 352                 '_SCL_SECURE_NO_DEPRECATE',
 353                 '_ALLOW_KEYWORD_MACROS',
 354                 '_HAS_EXCEPTIONS=0', # Tell C++ STL to not use exceptions
 355             ]
 356         if env['build'] in ('debug', 'checked'):
 357             cppdefines += ['_DEBUG']
 358     if platform == 'windows':
 359         cppdefines += ['PIPE_SUBSYSTEM_WINDOWS_USER']
 360     if env['embedded']:
 361         cppdefines += ['PIPE_SUBSYSTEM_EMBEDDED']
 362     if env['texture_float']:
 363         print 'warning: Floating-point textures enabled.'
 364         print 'warning: Please consult docs/patents.txt with your lawyer before building Mesa.'
 365         cppdefines += ['TEXTURE_FLOAT_ENABLED']
 366     env.Append(CPPDEFINES = cppdefines)
 367
 368     # C compiler options
 369     cflags = [] # C
 370     cxxflags = [] # C++
 371     ccflags = [] # C & C++
 372     if gcc_compat:
 373         if env['build'] == 'debug':
 374             ccflags += ['-O0']
 375         else:
 376             ccflags += ['-O3']
 377         if env['gcc']:
 378             # gcc's builtin memcmp is slower than glibc's
 379             # http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43052
 380             ccflags += ['-fno-builtin-memcmp']
 381         # Work around aliasing bugs - developers should comment this out
 382         ccflags += ['-fno-strict-aliasing']
 383         ccflags += ['-g']
 384         if env['build'] in ('checked', 'profile') or env['asan']:
 385             # See http://code.google.com/p/jrfonseca/wiki/Gprof2Dot#Which_options_should_I_pass_to_gcc_when_compiling_for_profiling?
 386             ccflags += [
 387                 '-fno-omit-frame-pointer',
 388             ]
 389             if env['gcc']:
 390                 ccflags += ['-fno-optimize-sibling-calls']
 391         if env['machine'] == 'x86':
 392             ccflags += [
 393                 '-m32',
 394                 #'-march=pentium4',
 395             ]
 396             if platform != 'haiku':
 397                 # NOTE: We need to ensure stack is realigned given that we
 398                 # produce shared objects, and have no control over the stack
 399                 # alignment policy of the application. Therefore we need
 400                 # -mstackrealign ore -mincoming-stack-boundary=2.
 401                 #
 402                 # XXX: We could have SSE without -mstackrealign if we always used
 403                 # __attribute__((force_align_arg_pointer)), but that's not
 404                 # always the case.
 405                 ccflags += [
 406                     '-mstackrealign', # ensure stack is aligned
 407                     '-msse', '-msse2', # enable SIMD intrinsics
 408                     '-mfpmath=sse', # generate SSE floating-point arithmetic
 409                 ]
 410             if platform in ['windows', 'darwin']:
 411                 # Workaround http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37216
 412                 ccflags += ['-fno-common']
 413             if platform in ['haiku']:
 414                 # Make optimizations compatible with Pentium or higher on Haiku
 415                 ccflags += [
 416                     '-mstackrealign', # ensure stack is aligned
 417                     '-march=i586', # Haiku target is Pentium
 418                     '-mtune=i686' # use i686 where we can
 419                 ]
 420         if env['machine'] == 'x86_64':
 421             ccflags += ['-m64']
 422             if platform == 'darwin':
 423                 ccflags += ['-fno-common']
 424         if env['platform'] not in ('cygwin', 'haiku', 'windows'):
 425             ccflags += ['-fvisibility=hidden']
 426         # See also:
 427         # - http://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html
 428         ccflags += [
 429             '-Wall',
 430             '-Wno-long-long',
 431             '-fmessage-length=0', # be nice to Eclipse
 432         ]
 433         cflags += [
 434             '-Wmissing-prototypes',
 435             '-std=gnu99',
 436         ]
 437     if icc:
 438         cflags += [
 439             '-std=gnu99',
 440         ]
 441     if msvc:
 442         # See also:
 443         # - http://msdn.microsoft.com/en-us/library/19z1t1wy.aspx
 444         # - cl /?
 445         if env['build'] == 'debug':
 446             ccflags += [
 447               '/Od', # disable optimizations
 448               '/Oi', # enable intrinsic functions
 449             ]
 450         else:
 451             ccflags += [
 452                 '/O2', # optimize for speed
 453             ]
 454         if env['build'] in ('release', 'opt'):
 455             if not env['clang']:
 456                 ccflags += [
 457                     '/GL', # enable whole program optimization
 458                 ]
 459         else:
 460             ccflags += [
 461                 '/Oy-', # disable frame pointer omission
 462             ]
 463         ccflags += [
 464             '/W3', # warning level
 465             '/wd4018', # signed/unsigned mismatch
 466             '/wd4056', # overflow in floating-point constant arithmetic
 467             '/wd4244', # conversion from 'type1' to 'type2', possible loss of data
 468             '/wd4267', # 'var' : conversion from 'size_t' to 'type', possible loss of data
 469             '/wd4305', # truncation from 'type1' to 'type2'
 470             '/wd4351', # new behavior: elements of array 'array' will be default initialized
 471             '/wd4756', # overflow in constant arithmetic
 472             '/wd4800', # forcing value to bool 'true' or 'false' (performance warning)
 473             '/wd4996', # disable deprecated POSIX name warnings
 474         ]
 475         if env['clang']:
 476             ccflags += [
 477                 '-Wno-microsoft-enum-value', # enumerator value is not representable in underlying type 'int'
 478             ]
 479         if env['machine'] == 'x86':
 480             ccflags += [
 481                 '/arch:SSE2', # use the SSE2 instructions (default since MSVC 2012)
 482             ]
 483         if platform == 'windows':
 484             ccflags += [
 485                 # TODO
 486             ]
 487         # Automatic pdb generation
 488         # See http://scons.tigris.org/issues/show_bug.cgi?id=1656
 489         env.EnsureSConsVersion(0, 98, 0)
 490         env['PDB'] = '${TARGET.base}.pdb'
 491     env.Append(CCFLAGS = ccflags)
 492     env.Append(CFLAGS = cflags)
 493     env.Append(CXXFLAGS = cxxflags)
 494
 495     if env['platform'] == 'windows' and msvc:
 496         # Choose the appropriate MSVC CRT
 497         # http://msdn.microsoft.com/en-us/library/2kzt1wy3.aspx
 498         if env['build'] in ('debug', 'checked'):
 499             env.Append(CCFLAGS = ['/MTd'])
 500             env.Append(SHCCFLAGS = ['/LDd'])
 501         else:
 502             env.Append(CCFLAGS = ['/MT'])
 503             env.Append(SHCCFLAGS = ['/LD'])
 504
 505     # Static code analysis
 506     if env['analyze']:
 507         if env['msvc']:
 508             # http://msdn.microsoft.com/en-us/library/ms173498.aspx
 509             env.Append(CCFLAGS = [
 510                 '/analyze',
 511                 #'/analyze:log', '${TARGET.base}.xml',
 512                 '/wd28251', # Inconsistent annotation for function
 513             ])
 514         if env['clang']:
 515             # scan-build will produce more comprehensive output
 516             env.Append(CCFLAGS = ['--analyze'])
 517
 518     # https://github.com/google/sanitizers/wiki/AddressSanitizer
 519     if env['asan']:
 520         if gcc_compat:
 521             env.Append(CCFLAGS = [
 522                 '-fsanitize=address',
 523             ])
 524             env.Append(LINKFLAGS = [
 525                 '-fsanitize=address',
 526             ])
 527
 528     # Assembler options
 529     if gcc_compat:
 530         if env['machine'] == 'x86':
 531             env.Append(ASFLAGS = ['-m32'])
 532         if env['machine'] == 'x86_64':
 533             env.Append(ASFLAGS = ['-m64'])
 534
 535     # Linker options
 536     linkflags = []
 537     shlinkflags = []
 538     if gcc_compat:
 539         if env['machine'] == 'x86':
 540             linkflags += ['-m32']
 541         if env['machine'] == 'x86_64':
 542             linkflags += ['-m64']
 543         if env['platform'] not in ('darwin'):
 544             shlinkflags += [
 545                 '-Wl,-Bsymbolic',
 546             ]
 547         # Handle circular dependencies in the libraries
 548         if env['platform'] in ('darwin'):
 549             pass
 550         else:
 551             env['_LIBFLAGS'] = '-Wl,--start-group ' + env['_LIBFLAGS'] + ' -Wl,--end-group'
 552         if env['platform'] == 'windows':
 553             linkflags += [
 554                 '-Wl,--nxcompat', # DEP
 555                 '-Wl,--dynamicbase', # ASLR
 556             ]
 557             # Avoid depending on gcc runtime DLLs
 558             linkflags += ['-static-libgcc']
 559             if 'w64' in env['CC'].split('-'):
 560                 linkflags += ['-static-libstdc++']
 561             # Handle the @xx symbol munging of DLL exports
 562             shlinkflags += ['-Wl,--enable-stdcall-fixup']
 563             #shlinkflags += ['-Wl,--kill-at']
 564     if msvc:
 565         if env['build'] in ('release', 'opt') and not env['clang']:
 566             # enable Link-time Code Generation
 567             linkflags += ['/LTCG']
 568             env.Append(ARFLAGS = ['/LTCG'])
 569     if platform == 'windows' and msvc:
 570         # See also:
 571         # - http://msdn2.microsoft.com/en-us/library/y0zzbyt4.aspx
 572         linkflags += [
 573             '/fixed:no',
 574             '/incremental:no',
 575             '/dynamicbase', # ASLR
 576             '/nxcompat', # DEP
 577         ]
 578     env.Append(LINKFLAGS = linkflags)
 579     env.Append(SHLINKFLAGS = shlinkflags)
 580
 581     # We have C++ in several libraries, so always link with the C++ compiler
 582     if gcc_compat:
 583         env['LINK'] = env['CXX']
 584
 585     # Default libs
 586     libs = []
 587     if env['platform'] in ('darwin', 'freebsd', 'linux', 'posix', 'sunos'):
 588         libs += ['m', 'pthread', 'dl']
 589     if env['platform'] in ('linux',):
 590         libs += ['rt']
 591     if env['platform'] in ('haiku'):
 592         libs += ['root', 'be', 'network', 'translation']
 593     env.Append(LIBS = libs)
 594
 595     # OpenMP
 596     if env['openmp']:
 597         if env['msvc']:
 598             env.Append(CCFLAGS = ['/openmp'])
 599             # When building openmp release VS2008 link.exe crashes with LNK1103 error.
 600             # Workaround: overwrite PDB flags with empty value as it isn't required anyways
 601             if env['build'] == 'release':
 602                 env['PDB'] = ''
 603         if env['gcc']:
 604             env.Append(CCFLAGS = ['-fopenmp'])
 605             env.Append(LIBS = ['gomp'])
 606
 607     # Load tools
 608     env.Tool('lex')
 609     if env['msvc']:
 610         env.Append(LEXFLAGS = [
 611             # Force flex to use const keyword in prototypes, as relies on
 612             # __cplusplus or __STDC__ macro to determine whether it's safe to
 613             # use const keyword, but MSVC never defines __STDC__ unless we
 614             # disable all MSVC extensions.
 615             '-DYY_USE_CONST=',
 616         ])
 617         # Flex relies on __STDC_VERSION__>=199901L to decide when to include
 618         # C99 inttypes.h.  We always have inttypes.h available with MSVC
 619         # (either the one bundled with MSVC 2013, or the one we bundle
 620         # ourselves), but we can't just define __STDC_VERSION__ without
 621         # breaking stuff, as MSVC doesn't fully support C99.  There's also no
 622         # way to premptively include stdint.
 623         env.Append(CCFLAGS = ['-FIinttypes.h'])
 624     if host_platform.system() == 'Windows':
 625         # Prefer winflexbison binaries, as not only they are easier to install
 626         # (no additional dependencies), but also better Windows support.
 627         if check_prog(env, 'win_flex'):
 628             env["LEX"] = 'win_flex'
 629             env.Append(LEXFLAGS = [
 630                 # windows compatibility (uses <io.h> instead of <unistd.h> and
 631                 # _isatty, _fileno functions)
 632                 '--wincompat'
 633             ])
 634
 635     env.Tool('yacc')
 636     if host_platform.system() == 'Windows':
 637         if check_prog(env, 'win_bison'):
 638             env["YACC"] = 'win_bison'
 639
 640     if env['llvm']:
 641         env.Tool('llvm')
 642
 643     # Custom builders and methods
 644     env.Tool('custom')
 645     env.AddMethod(install_program, 'InstallProgram')
 646     env.AddMethod(install_shared_library, 'InstallSharedLibrary')
 647     env.AddMethod(msvc2013_compat, 'MSVC2013Compat')
 648     env.AddMethod(unit_test, 'UnitTest')
 649
 650     env.PkgCheckModules('X11', ['x11', 'xext', 'xdamage >= 1.1', 'xfixes', 'glproto >= 1.4.13', 'dri2proto >= 2.8'])
 651     env.PkgCheckModules('XCB', ['x11-xcb', 'xcb-glx >= 1.8.1', 'xcb-dri2 >= 1.8'])
 652     env.PkgCheckModules('XF86VIDMODE', ['xxf86vm'])
 653     env.PkgCheckModules('DRM', ['libdrm >= 2.4.75'])
 654
 655     if env['x11']:
 656         env.Append(CPPPATH = env['X11_CPPPATH'])
 657
 658     env['dri'] = env['x11'] and env['drm']
 659
 660     # for debugging
 661     #print env.Dump()
 662
 663
 664 def exists(env):
 665     return 1