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 createInstallMethods(env):
  86     env.AddMethod(install_program, 'InstallProgram')
  87     env.AddMethod(install_shared_library, 'InstallSharedLibrary')
  88
  89
  90 def msvc2013_compat(env):
  91     if env['gcc']:
  92         env.Append(CCFLAGS = [
  93             '-Werror=vla',
  94             '-Werror=pointer-arith',
  95         ])
  96
  97 def msvc2008_compat(env):
  98     msvc2013_compat(env)
  99     if env['gcc']:
 100         env.Append(CFLAGS = [
 101             '-Werror=declaration-after-statement',
 102         ])
 103
 104 def createMSVCCompatMethods(env):
 105     env.AddMethod(msvc2013_compat, 'MSVC2013Compat')
 106     env.AddMethod(msvc2008_compat, 'MSVC2008Compat')
 107
 108
 109 def num_jobs():
 110     try:
 111         return int(os.environ['NUMBER_OF_PROCESSORS'])
 112     except (ValueError, KeyError):
 113         pass
 114
 115     try:
 116         return os.sysconf('SC_NPROCESSORS_ONLN')
 117     except (ValueError, OSError, AttributeError):
 118         pass
 119
 120     try:
 121         return int(os.popen2("sysctl -n hw.ncpu")[1].read())
 122     except ValueError:
 123         pass
 124
 125     return 1
 126
 127
 128 def check_cc(env, cc, expr, cpp_opt = '-E'):
 129     # Invoke C-preprocessor to determine whether the specified expression is
 130     # true or not.
 131
 132     sys.stdout.write('Checking for %s ... ' % cc)
 133
 134     source = tempfile.NamedTemporaryFile(suffix='.c', delete=False)
 135     source.write('#if !(%s)\n#error\n#endif\n' % expr)
 136     source.close()
 137
 138     pipe = SCons.Action._subproc(env, [env['CC'], cpp_opt, source.name],
 139                                  stdin = 'devnull',
 140                                  stderr = 'devnull',
 141                                  stdout = 'devnull')
 142     result = pipe.wait() == 0
 143
 144     os.unlink(source.name)
 145
 146     sys.stdout.write(' %s\n' % ['no', 'yes'][int(bool(result))])
 147     return result
 148
 149
 150 def check_prog(env, prog):
 151     """Check whether this program exists."""
 152
 153     sys.stdout.write('Checking for %s ... ' % prog)
 154
 155     result = env.Detect(prog)
 156
 157     sys.stdout.write(' %s\n' % ['no', 'yes'][int(bool(result))])
 158     return result
 159
 160
 161 def generate(env):
 162     """Common environment generation code"""
 163
 164     # Tell tools which machine to compile for
 165     env['TARGET_ARCH'] = env['machine']
 166     env['MSVS_ARCH'] = env['machine']
 167
 168     # Toolchain
 169     platform = env['platform']
 170     env.Tool(env['toolchain'])
 171
 172     # Allow override compiler and specify additional flags from environment
 173     if os.environ.has_key('CC'):
 174         env['CC'] = os.environ['CC']
 175         # Update CCVERSION to match
 176         pipe = SCons.Action._subproc(env, [env['CC'], '--version'],
 177                                      stdin = 'devnull',
 178                                      stderr = 'devnull',
 179                                      stdout = subprocess.PIPE)
 180         if pipe.wait() == 0:
 181             line = pipe.stdout.readline()
 182             match = re.search(r'[0-9]+(\.[0-9]+)+', line)
 183             if match:
 184                 env['CCVERSION'] = match.group(0)
 185     if os.environ.has_key('CFLAGS'):
 186         env['CCFLAGS'] += SCons.Util.CLVar(os.environ['CFLAGS'])
 187     if os.environ.has_key('CXX'):
 188         env['CXX'] = os.environ['CXX']
 189     if os.environ.has_key('CXXFLAGS'):
 190         env['CXXFLAGS'] += SCons.Util.CLVar(os.environ['CXXFLAGS'])
 191     if os.environ.has_key('LDFLAGS'):
 192         env['LINKFLAGS'] += SCons.Util.CLVar(os.environ['LDFLAGS'])
 193
 194     # Detect gcc/clang not by executable name, but through pre-defined macros
 195     # as autoconf does, to avoid drawing wrong conclusions when using tools
 196     # that overrice CC/CXX like scan-build.
 197     env['gcc'] = 0
 198     env['clang'] = 0
 199     env['msvc'] = 0
 200     if host_platform.system() == 'Windows':
 201         env['msvc'] = check_cc(env, 'MSVC', 'defined(_MSC_VER)', '/E')
 202     if not env['msvc']:
 203         env['gcc'] = check_cc(env, 'GCC', 'defined(__GNUC__) && !defined(__clang__)')
 204         env['clang'] = check_cc(env, 'Clang', '__clang__')
 205     env['suncc'] = env['platform'] == 'sunos' and os.path.basename(env['CC']) == 'cc'
 206     env['icc'] = 'icc' == os.path.basename(env['CC'])
 207
 208     if env['msvc'] and env['toolchain'] == 'default' and env['machine'] == 'x86_64':
 209         # MSVC x64 support is broken in earlier versions of scons
 210         env.EnsurePythonVersion(2, 0)
 211
 212     # shortcuts
 213     machine = env['machine']
 214     platform = env['platform']
 215     x86 = env['machine'] == 'x86'
 216     ppc = env['machine'] == 'ppc'
 217     gcc_compat = env['gcc'] or env['clang']
 218     msvc = env['msvc']
 219     suncc = env['suncc']
 220     icc = env['icc']
 221
 222     # Determine whether we are cross compiling; in particular, whether we need
 223     # to compile code generators with a different compiler as the target code.
 224     hosthost_platform = host_platform.system().lower()
 225     if hosthost_platform.startswith('cygwin'):
 226         hosthost_platform = 'cygwin'
 227     host_machine = os.environ.get('PROCESSOR_ARCHITEW6432', os.environ.get('PROCESSOR_ARCHITECTURE', host_platform.machine()))
 228     host_machine = {
 229         'x86': 'x86',
 230         'i386': 'x86',
 231         'i486': 'x86',
 232         'i586': 'x86',
 233         'i686': 'x86',
 234         'ppc' : 'ppc',
 235         'AMD64': 'x86_64',
 236         'x86_64': 'x86_64',
 237     }.get(host_machine, 'generic')
 238     env['crosscompile'] = platform != hosthost_platform
 239     if machine == 'x86_64' and host_machine != 'x86_64':
 240         env['crosscompile'] = True
 241     env['hostonly'] = False
 242
 243     # Backwards compatability with the debug= profile= options
 244     if env['build'] == 'debug':
 245         if not env['debug']:
 246             print 'scons: warning: debug option is deprecated and will be removed eventually; use instead'
 247             print
 248             print ' scons build=release'
 249             print
 250             env['build'] = 'release'
 251         if env['profile']:
 252             print 'scons: warning: profile option is deprecated and will be removed eventually; use instead'
 253             print
 254             print ' scons build=profile'
 255             print
 256             env['build'] = 'profile'
 257     if False:
 258         # Enforce SConscripts to use the new build variable
 259         env.popitem('debug')
 260         env.popitem('profile')
 261     else:
 262         # Backwards portability with older sconscripts
 263         if env['build'] in ('debug', 'checked'):
 264             env['debug'] = True
 265             env['profile'] = False
 266         if env['build'] == 'profile':
 267             env['debug'] = False
 268             env['profile'] = True
 269         if env['build'] == 'release':
 270             env['debug'] = False
 271             env['profile'] = False
 272
 273     # Put build output in a separate dir, which depends on the current
 274     # configuration. See also http://www.scons.org/wiki/AdvancedBuildExample
 275     build_topdir = 'build'
 276     build_subdir = env['platform']
 277     if env['embedded']:
 278         build_subdir =  'embedded-' + build_subdir
 279     if env['machine'] != 'generic':
 280         build_subdir += '-' + env['machine']
 281     if env['build'] != 'release':
 282         build_subdir += '-' +  env['build']
 283     build_dir = os.path.join(build_topdir, build_subdir)
 284     # Place the .sconsign file in the build dir too, to avoid issues with
 285     # different scons versions building the same source file
 286     env['build_dir'] = build_dir
 287     env.SConsignFile(os.path.join(build_dir, '.sconsign'))
 288     if 'SCONS_CACHE_DIR' in os.environ:
 289         print 'scons: Using build cache in %s.' % (os.environ['SCONS_CACHE_DIR'],)
 290         env.CacheDir(os.environ['SCONS_CACHE_DIR'])
 291     env['CONFIGUREDIR'] = os.path.join(build_dir, 'conf')
 292     env['CONFIGURELOG'] = os.path.join(os.path.abspath(build_dir), 'config.log')
 293
 294     # Parallel build
 295     if env.GetOption('num_jobs') <= 1:
 296         env.SetOption('num_jobs', num_jobs())
 297
 298     env.Decider('MD5-timestamp')
 299     env.SetOption('max_drift', 60)
 300
 301     # C preprocessor options
 302     cppdefines = []
 303     if env['build'] in ('debug', 'checked'):
 304         cppdefines += ['DEBUG']
 305     else:
 306         cppdefines += ['NDEBUG']
 307     if env['build'] == 'profile':
 308         cppdefines += ['PROFILE']
 309     if env['platform'] in ('posix', 'linux', 'freebsd', 'darwin'):
 310         cppdefines += [
 311             '_POSIX_SOURCE',
 312             ('_POSIX_C_SOURCE', '199309L'),
 313             '_SVID_SOURCE',
 314             '_BSD_SOURCE',
 315             '_GNU_SOURCE',
 316             '_DEFAULT_SOURCE',
 317             'HAVE_PTHREAD',
 318             'HAVE_POSIX_MEMALIGN',
 319         ]
 320         if env['platform'] == 'darwin':
 321             cppdefines += [
 322                 '_DARWIN_C_SOURCE',
 323                 'GLX_USE_APPLEGL',
 324                 'GLX_DIRECT_RENDERING',
 325             ]
 326         else:
 327             cppdefines += [
 328                 'GLX_DIRECT_RENDERING',
 329                 'GLX_INDIRECT_RENDERING',
 330             ]
 331         if env['platform'] in ('linux', 'freebsd'):
 332             cppdefines += ['HAVE_ALIAS']
 333         else:
 334             cppdefines += ['GLX_ALIAS_UNSUPPORTED']
 335
 336         if env['platform'] in ('linux', 'darwin'):
 337             cppdefines += ['HAVE_XLOCALE_H']
 338
 339     if env['platform'] == 'haiku':
 340         cppdefines += [
 341             'HAVE_PTHREAD',
 342             'HAVE_POSIX_MEMALIGN'
 343         ]
 344     if platform == 'windows':
 345         cppdefines += [
 346             'WIN32',
 347             '_WINDOWS',
 348             #'_UNICODE',
 349             #'UNICODE',
 350             # http://msdn.microsoft.com/en-us/library/aa383745.aspx
 351             ('_WIN32_WINNT', '0x0601'),
 352             ('WINVER', '0x0601'),
 353         ]
 354         if gcc_compat:
 355             cppdefines += [('__MSVCRT_VERSION__', '0x0700')]
 356         if msvc:
 357             cppdefines += [
 358                 'VC_EXTRALEAN',
 359                 '_USE_MATH_DEFINES',
 360                 '_CRT_SECURE_NO_WARNINGS',
 361                 '_CRT_SECURE_NO_DEPRECATE',
 362                 '_SCL_SECURE_NO_WARNINGS',
 363                 '_SCL_SECURE_NO_DEPRECATE',
 364                 '_ALLOW_KEYWORD_MACROS',
 365                 '_HAS_EXCEPTIONS=0', # Tell C++ STL to not use exceptions
 366             ]
 367         if env['build'] in ('debug', 'checked'):
 368             cppdefines += ['_DEBUG']
 369     if platform == 'windows':
 370         cppdefines += ['PIPE_SUBSYSTEM_WINDOWS_USER']
 371     if env['embedded']:
 372         cppdefines += ['PIPE_SUBSYSTEM_EMBEDDED']
 373     if env['texture_float']:
 374         print 'warning: Floating-point textures enabled.'
 375         print 'warning: Please consult docs/patents.txt with your lawyer before building Mesa.'
 376         cppdefines += ['TEXTURE_FLOAT_ENABLED']
 377     if gcc_compat:
 378         ccversion = env['CCVERSION']
 379         cppdefines += [
 380             'HAVE___BUILTIN_EXPECT',
 381             'HAVE___BUILTIN_FFS',
 382             'HAVE___BUILTIN_FFSLL',
 383             'HAVE_FUNC_ATTRIBUTE_FLATTEN',
 384             'HAVE_FUNC_ATTRIBUTE_UNUSED',
 385             # GCC 3.0
 386             'HAVE_FUNC_ATTRIBUTE_FORMAT',
 387             'HAVE_FUNC_ATTRIBUTE_PACKED',
 388             # GCC 3.4
 389             'HAVE___BUILTIN_CTZ',
 390             'HAVE___BUILTIN_POPCOUNT',
 391             'HAVE___BUILTIN_POPCOUNTLL',
 392             'HAVE___BUILTIN_CLZ',
 393             'HAVE___BUILTIN_CLZLL',
 394         ]
 395         if distutils.version.LooseVersion(ccversion) >= distutils.version.LooseVersion('4.5'):
 396             cppdefines += ['HAVE___BUILTIN_UNREACHABLE']
 397     env.Append(CPPDEFINES = cppdefines)
 398
 399     # C compiler options
 400     cflags = [] # C
 401     cxxflags = [] # C++
 402     ccflags = [] # C & C++
 403     if gcc_compat:
 404         ccversion = env['CCVERSION']
 405         if env['build'] == 'debug':
 406             ccflags += ['-O0']
 407         elif env['gcc'] and ccversion.startswith('4.2.'):
 408             # gcc 4.2.x optimizer is broken
 409             print "warning: gcc 4.2.x optimizer is broken -- disabling optimizations"
 410             ccflags += ['-O0']
 411         else:
 412             ccflags += ['-O3']
 413         if env['gcc']:
 414             # gcc's builtin memcmp is slower than glibc's
 415             # http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43052
 416             ccflags += ['-fno-builtin-memcmp']
 417         # Work around aliasing bugs - developers should comment this out
 418         ccflags += ['-fno-strict-aliasing']
 419         ccflags += ['-g']
 420         if env['build'] in ('checked', 'profile'):
 421             # See http://code.google.com/p/jrfonseca/wiki/Gprof2Dot#Which_options_should_I_pass_to_gcc_when_compiling_for_profiling?
 422             ccflags += [
 423                 '-fno-omit-frame-pointer',
 424             ]
 425             if env['gcc']:
 426                 ccflags += ['-fno-optimize-sibling-calls']
 427         if env['machine'] == 'x86':
 428             ccflags += [
 429                 '-m32',
 430                 #'-march=pentium4',
 431             ]
 432             if platform != 'haiku':
 433                 # NOTE: We need to ensure stack is realigned given that we
 434                 # produce shared objects, and have no control over the stack
 435                 # alignment policy of the application. Therefore we need
 436                 # -mstackrealign ore -mincoming-stack-boundary=2.
 437                 #
 438                 # XXX: We could have SSE without -mstackrealign if we always used
 439                 # __attribute__((force_align_arg_pointer)), but that's not
 440                 # always the case.
 441                 ccflags += [
 442                     '-mstackrealign', # ensure stack is aligned
 443                     '-msse', '-msse2', # enable SIMD intrinsics
 444                     '-mfpmath=sse', # generate SSE floating-point arithmetic
 445                 ]
 446             if platform in ['windows', 'darwin']:
 447                 # Workaround http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37216
 448                 ccflags += ['-fno-common']
 449             if platform in ['haiku']:
 450                 # Make optimizations compatible with Pentium or higher on Haiku
 451                 ccflags += [
 452                     '-mstackrealign', # ensure stack is aligned
 453                     '-march=i586', # Haiku target is Pentium
 454                     '-mtune=i686' # use i686 where we can
 455                 ]
 456         if env['machine'] == 'x86_64':
 457             ccflags += ['-m64']
 458             if platform == 'darwin':
 459                 ccflags += ['-fno-common']
 460         if env['platform'] not in ('cygwin', 'haiku', 'windows'):
 461             ccflags += ['-fvisibility=hidden']
 462         # See also:
 463         # - http://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html
 464         ccflags += [
 465             '-Wall',
 466             '-Wno-long-long',
 467             '-fmessage-length=0', # be nice to Eclipse
 468         ]
 469         cflags += [
 470             '-Wmissing-prototypes',
 471             '-std=gnu99',
 472         ]
 473     if icc:
 474         cflags += [
 475             '-std=gnu99',
 476         ]
 477     if msvc:
 478         # See also:
 479         # - http://msdn.microsoft.com/en-us/library/19z1t1wy.aspx
 480         # - cl /?
 481         if 'MSVC_VERSION' not in env or distutils.version.LooseVersion(env['MSVC_VERSION']) < distutils.version.LooseVersion('12.0'):
 482             # Use bundled stdbool.h and stdint.h headers for older MSVC
 483             # versions.  stdint.h was introduced in MSVC 2010, but stdbool.h
 484             # was only introduced in MSVC 2013.
 485             top_dir = os.path.abspath(os.path.join(os.path.dirname(__file__), '..'))
 486             env.Append(CPPPATH = [os.path.join(top_dir, 'include/c99')])
 487         if env['build'] == 'debug':
 488             ccflags += [
 489               '/Od', # disable optimizations
 490               '/Oi', # enable intrinsic functions
 491             ]
 492         else:
 493             if 'MSVC_VERSION' in env and distutils.version.LooseVersion(env['MSVC_VERSION']) < distutils.version.LooseVersion('11.0'):
 494                 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 )'
 495             ccflags += [
 496                 '/O2', # optimize for speed
 497             ]
 498         if env['build'] == 'release':
 499             ccflags += [
 500                 '/GL', # enable whole program optimization
 501             ]
 502         else:
 503             ccflags += [
 504                 '/Oy-', # disable frame pointer omission
 505                 '/GL-', # disable whole program optimization
 506             ]
 507         ccflags += [
 508             '/W3', # warning level
 509             '/wd4018', # signed/unsigned mismatch
 510             '/wd4056', # overflow in floating-point constant arithmetic
 511             '/wd4244', # conversion from 'type1' to 'type2', possible loss of data
 512             '/wd4305', # truncation from 'type1' to 'type2'
 513             '/wd4756', # overflow in constant arithmetic
 514             '/wd4800', # forcing value to bool 'true' or 'false' (performance warning)
 515             '/wd4996', # disable deprecated POSIX name warnings
 516         ]
 517         if env['machine'] == 'x86':
 518             ccflags += [
 519                 '/arch:SSE2', # use the SSE2 instructions (default since MSVC 2012)
 520             ]
 521         if platform == 'windows':
 522             ccflags += [
 523                 # TODO
 524             ]
 525         # Automatic pdb generation
 526         # See http://scons.tigris.org/issues/show_bug.cgi?id=1656
 527         env.EnsureSConsVersion(0, 98, 0)
 528         env['PDB'] = '${TARGET.base}.pdb'
 529     env.Append(CCFLAGS = ccflags)
 530     env.Append(CFLAGS = cflags)
 531     env.Append(CXXFLAGS = cxxflags)
 532
 533     if env['platform'] == 'windows' and msvc:
 534         # Choose the appropriate MSVC CRT
 535         # http://msdn.microsoft.com/en-us/library/2kzt1wy3.aspx
 536         if env['build'] in ('debug', 'checked'):
 537             env.Append(CCFLAGS = ['/MTd'])
 538             env.Append(SHCCFLAGS = ['/LDd'])
 539         else:
 540             env.Append(CCFLAGS = ['/MT'])
 541             env.Append(SHCCFLAGS = ['/LD'])
 542
 543     # Static code analysis
 544     if env['analyze']:
 545         if env['msvc']:
 546             # http://msdn.microsoft.com/en-us/library/ms173498.aspx
 547             env.Append(CCFLAGS = [
 548                 '/analyze',
 549                 #'/analyze:log', '${TARGET.base}.xml',
 550             ])
 551         if env['clang']:
 552             # scan-build will produce more comprehensive output
 553             env.Append(CCFLAGS = ['--analyze'])
 554
 555     # Assembler options
 556     if gcc_compat:
 557         if env['machine'] == 'x86':
 558             env.Append(ASFLAGS = ['-m32'])
 559         if env['machine'] == 'x86_64':
 560             env.Append(ASFLAGS = ['-m64'])
 561
 562     # Linker options
 563     linkflags = []
 564     shlinkflags = []
 565     if gcc_compat:
 566         if env['machine'] == 'x86':
 567             linkflags += ['-m32']
 568         if env['machine'] == 'x86_64':
 569             linkflags += ['-m64']
 570         if env['platform'] not in ('darwin'):
 571             shlinkflags += [
 572                 '-Wl,-Bsymbolic',
 573             ]
 574         # Handle circular dependencies in the libraries
 575         if env['platform'] in ('darwin'):
 576             pass
 577         else:
 578             env['_LIBFLAGS'] = '-Wl,--start-group ' + env['_LIBFLAGS'] + ' -Wl,--end-group'
 579         if env['platform'] == 'windows':
 580             linkflags += [
 581                 '-Wl,--nxcompat', # DEP
 582                 '-Wl,--dynamicbase', # ASLR
 583             ]
 584             # Avoid depending on gcc runtime DLLs
 585             linkflags += ['-static-libgcc']
 586             if 'w64' in env['CC'].split('-'):
 587                 linkflags += ['-static-libstdc++']
 588             # Handle the @xx symbol munging of DLL exports
 589             shlinkflags += ['-Wl,--enable-stdcall-fixup']
 590             #shlinkflags += ['-Wl,--kill-at']
 591     if msvc:
 592         if env['build'] == 'release':
 593             # enable Link-time Code Generation
 594             linkflags += ['/LTCG']
 595             env.Append(ARFLAGS = ['/LTCG'])
 596     if platform == 'windows' and msvc:
 597         # See also:
 598         # - http://msdn2.microsoft.com/en-us/library/y0zzbyt4.aspx
 599         linkflags += [
 600             '/fixed:no',
 601             '/incremental:no',
 602             '/dynamicbase', # ASLR
 603             '/nxcompat', # DEP
 604         ]
 605     env.Append(LINKFLAGS = linkflags)
 606     env.Append(SHLINKFLAGS = shlinkflags)
 607
 608     # We have C++ in several libraries, so always link with the C++ compiler
 609     if gcc_compat:
 610         env['LINK'] = env['CXX']
 611
 612     # Default libs
 613     libs = []
 614     if env['platform'] in ('darwin', 'freebsd', 'linux', 'posix', 'sunos'):
 615         libs += ['m', 'pthread', 'dl']
 616     if env['platform'] in ('linux',):
 617         libs += ['rt']
 618     if env['platform'] in ('haiku'):
 619         libs += ['root', 'be', 'network', 'translation']
 620     env.Append(LIBS = libs)
 621
 622     # OpenMP
 623     if env['openmp']:
 624         if env['msvc']:
 625             env.Append(CCFLAGS = ['/openmp'])
 626             # When building openmp release VS2008 link.exe crashes with LNK1103 error.
 627             # Workaround: overwrite PDB flags with empty value as it isn't required anyways
 628             if env['build'] == 'release':
 629                 env['PDB'] = ''
 630         if env['gcc']:
 631             env.Append(CCFLAGS = ['-fopenmp'])
 632             env.Append(LIBS = ['gomp'])
 633
 634     # Load tools
 635     env.Tool('lex')
 636     if env['msvc']:
 637         env.Append(LEXFLAGS = [
 638             # Force flex to use const keyword in prototypes, as relies on
 639             # __cplusplus or __STDC__ macro to determine whether it's safe to
 640             # use const keyword, but MSVC never defines __STDC__ unless we
 641             # disable all MSVC extensions.
 642             '-DYY_USE_CONST=',
 643         ])
 644     if host_platform.system() == 'Windows':
 645         # Prefer winflexbison binaries, as not only they are easier to install
 646         # (no additional dependencies), but also better Windows support.
 647         if check_prog(env, 'win_flex'):
 648             env["LEX"] = 'win_flex'
 649             env.Append(LEXFLAGS = [
 650                 # windows compatibility (uses <io.h> instead of <unistd.h> and
 651                 # _isatty, _fileno functions)
 652                 '--wincompat'
 653             ])
 654
 655     env.Tool('yacc')
 656     if host_platform.system() == 'Windows':
 657         if check_prog(env, 'win_bison'):
 658             env["YACC"] = 'win_bison'
 659
 660     if env['llvm']:
 661         env.Tool('llvm')
 662
 663     # Custom builders and methods
 664     env.Tool('custom')
 665     createInstallMethods(env)
 666     createMSVCCompatMethods(env)
 667
 668     env.PkgCheckModules('X11', ['x11', 'xext', 'xdamage', 'xfixes', 'glproto >= 1.4.13'])
 669     env.PkgCheckModules('XCB', ['x11-xcb', 'xcb-glx >= 1.8.1', 'xcb-dri2 >= 1.8'])
 670     env.PkgCheckModules('XF86VIDMODE', ['xxf86vm'])
 671     env.PkgCheckModules('DRM', ['libdrm >= 2.4.38'])
 672     env.PkgCheckModules('UDEV', ['libudev >= 151'])
 673
 674     if env['x11']:
 675         env.Append(CPPPATH = env['X11_CPPPATH'])
 676
 677     env['dri'] = env['x11'] and env['drm']
 678
 679     # for debugging
 680     #print env.Dump()
 681
 682
 683 def exists(env):
 684     return 1