scons/gallium.py - platform/external/mesa3d - Gitiles

 """gallium

 Frontend-tool for Gallium3D architecture.

 """

 #
 # Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas.
 # All Rights Reserved.
 #
 # Permission is hereby granted, free of charge, to any person obtaining a
 # copy of this software and associated documentation files (the
 # "Software"), to deal in the Software without restriction, including
 # without limitation the rights to use, copy, modify, merge, publish,
 # distribute, sub license, and/or sell copies of the Software, and to
 # permit persons to whom the Software is furnished to do so, subject to
 # the following conditions:
 #
 # The above copyright notice and this permission notice (including the
 # next paragraph) shall be included in all copies or substantial portions
 # of the Software.
 #
 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 # OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
 # IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
 # ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 # TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 # SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #


 import distutils.version
 import os
 import os.path
 import re
 import subprocess
 import platform as _platform

 import SCons.Action
 import SCons.Builder
 import SCons.Scanner


 def symlink(target, source, env):
     target = str(target[0])
     source = str(source[0])
     if os.path.islink(target) or os.path.exists(target):
         os.remove(target)
     os.symlink(os.path.basename(source), target)

 def install(env, source, subdir):
     target_dir = os.path.join(env.Dir('#.').srcnode().abspath, env['build_dir'], subdir)
     return env.Install(target_dir, source)

 def install_program(env, source):
     return install(env, source, 'bin')

 def install_shared_library(env, sources, version = ()):
     targets = []
     install_dir = os.path.join(env.Dir('#.').srcnode().abspath, env['build_dir'])
     version = tuple(map(str, version))
     if env['SHLIBSUFFIX'] == '.dll':
         dlls = env.FindIxes(sources, 'SHLIBPREFIX', 'SHLIBSUFFIX')
         targets += install(env, dlls, 'bin')
         libs = env.FindIxes(sources, 'LIBPREFIX', 'LIBSUFFIX')
         targets += install(env, libs, 'lib')
     else:
         for source in sources:
             target_dir =  os.path.join(install_dir, 'lib')
             target_name = '.'.join((str(source),) + version)
             last = env.InstallAs(os.path.join(target_dir, target_name), source)
             targets += last
             while len(version):
                 version = version[:-1]
                 target_name = '.'.join((str(source),) + version)
                 action = SCons.Action.Action(symlink, "  Symlinking $TARGET ...")
                 last = env.Command(os.path.join(target_dir, target_name), last, action)
                 targets += last
     return targets


 def createInstallMethods(env):
     env.AddMethod(install_program, 'InstallProgram')
     env.AddMethod(install_shared_library, 'InstallSharedLibrary')


 def num_jobs():
     try:
         return int(os.environ['NUMBER_OF_PROCESSORS'])
     except (ValueError, KeyError):
         pass

     try:
         return os.sysconf('SC_NPROCESSORS_ONLN')
     except (ValueError, OSError, AttributeError):
         pass

     try:
         return int(os.popen2("sysctl -n hw.ncpu")[1].read())
     except ValueError:
         pass

     return 1


 def generate(env):
     """Common environment generation code"""

     # Tell tools which machine to compile for
     env['TARGET_ARCH'] = env['machine']
     env['MSVS_ARCH'] = env['machine']

     # Toolchain
     platform = env['platform']
     env.Tool(env['toolchain'])

     # Allow override compiler and specify additional flags from environment
     if os.environ.has_key('CC'):
         env['CC'] = os.environ['CC']
         # Update CCVERSION to match
         pipe = SCons.Action._subproc(env, [env['CC'], '--version'],
                                      stdin = 'devnull',
                                      stderr = 'devnull',
                                      stdout = subprocess.PIPE)
         if pipe.wait() == 0:
             line = pipe.stdout.readline()
             match = re.search(r'[0-9]+(\.[0-9]+)+', line)
             if match:
                 env['CCVERSION'] = match.group(0)
     if os.environ.has_key('CFLAGS'):
         env['CCFLAGS'] += SCons.Util.CLVar(os.environ['CFLAGS'])
     if os.environ.has_key('CXX'):
         env['CXX'] = os.environ['CXX']
     if os.environ.has_key('CXXFLAGS'):
         env['CXXFLAGS'] += SCons.Util.CLVar(os.environ['CXXFLAGS'])
     if os.environ.has_key('LDFLAGS'):
         env['LINKFLAGS'] += SCons.Util.CLVar(os.environ['LDFLAGS'])

     env['gcc'] = 'gcc' in os.path.basename(env['CC']).split('-')
     env['msvc'] = env['CC'] == 'cl'
     env['suncc'] = env['platform'] == 'sunos' and os.path.basename(env['CC']) == 'cc'
     env['clang'] = env['CC'] == 'clang'
     env['icc'] = 'icc' == os.path.basename(env['CC'])

     if env['msvc'] and env['toolchain'] == 'default' and env['machine'] == 'x86_64':
         # MSVC x64 support is broken in earlier versions of scons
         env.EnsurePythonVersion(2, 0)

     # shortcuts
     machine = env['machine']
     platform = env['platform']
     x86 = env['machine'] == 'x86'
     ppc = env['machine'] == 'ppc'
     gcc_compat = env['gcc'] or env['clang']
     msvc = env['msvc']
     suncc = env['suncc']
     icc = env['icc']

     # Determine whether we are cross compiling; in particular, whether we need
     # to compile code generators with a different compiler as the target code.
     host_platform = _platform.system().lower()
     if host_platform.startswith('cygwin'):
         host_platform = 'cygwin'
     host_machine = os.environ.get('PROCESSOR_ARCHITEW6432', os.environ.get('PROCESSOR_ARCHITECTURE', _platform.machine()))
     host_machine = {
         'x86': 'x86',
         'i386': 'x86',
         'i486': 'x86',
         'i586': 'x86',
         'i686': 'x86',
         'ppc' : 'ppc',
         'AMD64': 'x86_64',
         'x86_64': 'x86_64',
     }.get(host_machine, 'generic')
     env['crosscompile'] = platform != host_platform
     if machine == 'x86_64' and host_machine != 'x86_64':
         env['crosscompile'] = True
     env['hostonly'] = False

     # Backwards compatability with the debug= profile= options
     if env['build'] == 'debug':
         if not env['debug']:
             print 'scons: warning: debug option is deprecated and will be removed eventually; use instead'
             print
             print ' scons build=release'
             print
             env['build'] = 'release'
         if env['profile']:
             print 'scons: warning: profile option is deprecated and will be removed eventually; use instead'
             print
             print ' scons build=profile'
             print
             env['build'] = 'profile'
     if False:
         # Enforce SConscripts to use the new build variable
         env.popitem('debug')
         env.popitem('profile')
     else:
         # Backwards portability with older sconscripts
         if env['build'] in ('debug', 'checked'):
             env['debug'] = True
             env['profile'] = False
         if env['build'] == 'profile':
             env['debug'] = False
             env['profile'] = True
         if env['build'] == 'release':
             env['debug'] = False
             env['profile'] = False

     # Put build output in a separate dir, which depends on the current
     # configuration. See also http://www.scons.org/wiki/AdvancedBuildExample
     build_topdir = 'build'
     build_subdir = env['platform']
     if env['embedded']:
         build_subdir =  'embedded-' + build_subdir
     if env['machine'] != 'generic':
         build_subdir += '-' + env['machine']
     if env['build'] != 'release':
         build_subdir += '-' +  env['build']
     build_dir = os.path.join(build_topdir, build_subdir)
     # Place the .sconsign file in the build dir too, to avoid issues with
     # different scons versions building the same source file
     env['build_dir'] = build_dir
     env.SConsignFile(os.path.join(build_dir, '.sconsign'))
     if 'SCONS_CACHE_DIR' in os.environ:
         print 'scons: Using build cache in %s.' % (os.environ['SCONS_CACHE_DIR'],)
         env.CacheDir(os.environ['SCONS_CACHE_DIR'])
     env['CONFIGUREDIR'] = os.path.join(build_dir, 'conf')
     env['CONFIGURELOG'] = os.path.join(os.path.abspath(build_dir), 'config.log')

     # Parallel build
     if env.GetOption('num_jobs') <= 1:
         env.SetOption('num_jobs', num_jobs())

     env.Decider('MD5-timestamp')
     env.SetOption('max_drift', 60)

     # C preprocessor options
     cppdefines = []
     if env['build'] in ('debug', 'checked'):
         cppdefines += ['DEBUG']
     else:
         cppdefines += ['NDEBUG']
     if env['build'] == 'profile':
         cppdefines += ['PROFILE']
     if env['platform'] in ('posix', 'linux', 'freebsd', 'darwin'):
         cppdefines += [
             '_POSIX_SOURCE',
             ('_POSIX_C_SOURCE', '199309L'),
             '_SVID_SOURCE',
             '_BSD_SOURCE',
             '_GNU_SOURCE',
             'HAVE_PTHREAD',
             'HAVE_POSIX_MEMALIGN',
         ]
         if env['platform'] == 'darwin':
             cppdefines += [
                 '_DARWIN_C_SOURCE',
                 'GLX_USE_APPLEGL',
                 'GLX_DIRECT_RENDERING',
             ]
         else:
             cppdefines += [
                 'GLX_DIRECT_RENDERING',
                 'GLX_INDIRECT_RENDERING',
             ]
         if env['platform'] in ('linux', 'freebsd'):
             cppdefines += ['HAVE_ALIAS']
         else:
             cppdefines += ['GLX_ALIAS_UNSUPPORTED']
     if platform == 'windows':
         cppdefines += [
             'WIN32',
             '_WINDOWS',
             #'_UNICODE',
             #'UNICODE',
             # http://msdn.microsoft.com/en-us/library/aa383745.aspx
             ('_WIN32_WINNT', '0x0601'),
             ('WINVER', '0x0601'),
         ]
         if gcc_compat:
             cppdefines += [('__MSVCRT_VERSION__', '0x0700')]
         if msvc:
             cppdefines += [
                 'VC_EXTRALEAN',
                 '_USE_MATH_DEFINES',
                 '_CRT_SECURE_NO_WARNINGS',
                 '_CRT_SECURE_NO_DEPRECATE',
                 '_SCL_SECURE_NO_WARNINGS',
                 '_SCL_SECURE_NO_DEPRECATE',
                 '_ALLOW_KEYWORD_MACROS',
             ]
         if env['build'] in ('debug', 'checked'):
             cppdefines += ['_DEBUG']
     if platform == 'windows':
         cppdefines += ['PIPE_SUBSYSTEM_WINDOWS_USER']
     if platform == 'haiku':
         cppdefines += ['BEOS_THREADS']
     if env['embedded']:
         cppdefines += ['PIPE_SUBSYSTEM_EMBEDDED']
     if env['texture_float']:
         print 'warning: Floating-point textures enabled.'
         print 'warning: Please consult docs/patents.txt with your lawyer before building Mesa.'
         cppdefines += ['TEXTURE_FLOAT_ENABLED']
     env.Append(CPPDEFINES = cppdefines)

     # C compiler options
     cflags = [] # C
     cxxflags = [] # C++
     ccflags = [] # C & C++
     if gcc_compat:
         ccversion = env['CCVERSION']
         if env['build'] == 'debug':
             ccflags += ['-O0']
         elif env['gcc'] and ccversion.startswith('4.2.'):
             # gcc 4.2.x optimizer is broken
             print "warning: gcc 4.2.x optimizer is broken -- disabling optimizations"
             ccflags += ['-O0']
         else:
             ccflags += ['-O3']
         if env['gcc']:
             # gcc's builtin memcmp is slower than glibc's
             # http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43052
             ccflags += ['-fno-builtin-memcmp']
         # Work around aliasing bugs - developers should comment this out
         ccflags += ['-fno-strict-aliasing']
         ccflags += ['-g']
         if env['build'] in ('checked', 'profile'):
             # See http://code.google.com/p/jrfonseca/wiki/Gprof2Dot#Which_options_should_I_pass_to_gcc_when_compiling_for_profiling?
             ccflags += [
                 '-fno-omit-frame-pointer',
             ]
             if env['gcc']:
                 ccflags += ['-fno-optimize-sibling-calls']
         if env['machine'] == 'x86':
             ccflags += [
                 '-m32',
                 #'-march=pentium4',
             ]
             if distutils.version.LooseVersion(ccversion) >= distutils.version.LooseVersion('4.2') \
                and (platform != 'windows' or env['build'] == 'debug' or True) \
                and platform != 'haiku':
                 # NOTE: We need to ensure stack is realigned given that we
                 # produce shared objects, and have no control over the stack
                 # alignment policy of the application. Therefore we need
                 # -mstackrealign ore -mincoming-stack-boundary=2.
                 #
                 # XXX: -O and -mstackrealign causes stack corruption on MinGW
                 #
                 # XXX: We could have SSE without -mstackrealign if we always used
                 # __attribute__((force_align_arg_pointer)), but that's not
                 # always the case.
                 ccflags += [
                     '-mstackrealign', # ensure stack is aligned
                     '-mmmx', '-msse', '-msse2', # enable SIMD intrinsics
                     #'-mfpmath=sse',
                 ]
             if platform in ['windows', 'darwin']:
                 # Workaround http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37216
                 ccflags += ['-fno-common']
             if platform in ['haiku']:
                 # Make optimizations compatible with Pentium or higher on Haiku
                 ccflags += [
                     '-mstackrealign', # ensure stack is aligned
                     '-march=i586', # Haiku target is Pentium
                     '-mtune=i686' # use i686 where we can
                 ]
         if env['machine'] == 'x86_64':
             ccflags += ['-m64']
             if platform == 'darwin':
                 ccflags += ['-fno-common']
         if env['platform'] not in ('cygwin', 'haiku', 'windows'):
             ccflags += ['-fvisibility=hidden']
         # See also:
         # - http://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html
         ccflags += [
             '-Wall',
             '-Wno-long-long',
             '-fmessage-length=0', # be nice to Eclipse
         ]
         cflags += [
             '-Wmissing-prototypes',
             '-std=gnu99',
         ]
         if distutils.version.LooseVersion(ccversion) >= distutils.version.LooseVersion('4.2'):
             ccflags += [
                 '-Wpointer-arith',
             ]
             cflags += [
                 '-Wdeclaration-after-statement',
             ]
     if icc:
         cflags += [
             '-std=gnu99',
         ]
     if msvc:
         # See also:
         # - http://msdn.microsoft.com/en-us/library/19z1t1wy.aspx
         # - cl /?
         if env['build'] == 'debug':
             ccflags += [
               '/Od', # disable optimizations
               '/Oi', # enable intrinsic functions
             ]
         else:
             if 'MSVC_VERSION' in env and distutils.version.LooseVersion(env['MSVC_VERSION']) < distutils.version.LooseVersion('11.0'):
                 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 )'
             ccflags += [
                 '/O2', # optimize for speed
             ]
         if env['build'] == 'release':
             ccflags += [
                 '/GL', # enable whole program optimization
             ]
         else:
             ccflags += [
                 '/Oy-', # disable frame pointer omission
                 '/GL-', # disable whole program optimization
             ]
         ccflags += [
             '/W3', # warning level
             #'/Wp64', # enable 64 bit porting warnings
             '/wd4996', # disable deprecated POSIX name warnings
         ]
         if env['machine'] == 'x86':
             ccflags += [
                 #'/arch:SSE2', # use the SSE2 instructions
             ]
         if platform == 'windows':
             ccflags += [
                 # TODO
             ]
         # Automatic pdb generation
         # See http://scons.tigris.org/issues/show_bug.cgi?id=1656
         env.EnsureSConsVersion(0, 98, 0)
         env['PDB'] = '${TARGET.base}.pdb'
     env.Append(CCFLAGS = ccflags)
     env.Append(CFLAGS = cflags)
     env.Append(CXXFLAGS = cxxflags)

     if env['platform'] == 'windows' and msvc:
         # Choose the appropriate MSVC CRT
         # http://msdn.microsoft.com/en-us/library/2kzt1wy3.aspx
         if env['build'] in ('debug', 'checked'):
             env.Append(CCFLAGS = ['/MTd'])
             env.Append(SHCCFLAGS = ['/LDd'])
         else:
             env.Append(CCFLAGS = ['/MT'])
             env.Append(SHCCFLAGS = ['/LD'])

     # Assembler options
     if gcc_compat:
         if env['machine'] == 'x86':
             env.Append(ASFLAGS = ['-m32'])
         if env['machine'] == 'x86_64':
             env.Append(ASFLAGS = ['-m64'])

     # Linker options
     linkflags = []
     shlinkflags = []
     if gcc_compat:
         if env['machine'] == 'x86':
             linkflags += ['-m32']
         if env['machine'] == 'x86_64':
             linkflags += ['-m64']
         if env['platform'] not in ('darwin'):
             shlinkflags += [
                 '-Wl,-Bsymbolic',
             ]
         # Handle circular dependencies in the libraries
         if env['platform'] in ('darwin'):
             pass
         else:
             env['_LIBFLAGS'] = '-Wl,--start-group ' + env['_LIBFLAGS'] + ' -Wl,--end-group'
         if env['platform'] == 'windows':
             # Avoid depending on gcc runtime DLLs
             linkflags += ['-static-libgcc']
             if 'w64' in env['CC'].split('-'):
                 linkflags += ['-static-libstdc++']
             # Handle the @xx symbol munging of DLL exports
             shlinkflags += ['-Wl,--enable-stdcall-fixup']
             #shlinkflags += ['-Wl,--kill-at']
     if msvc:
         if env['build'] == 'release':
             # enable Link-time Code Generation
             linkflags += ['/LTCG']
             env.Append(ARFLAGS = ['/LTCG'])
     if platform == 'windows' and msvc:
         # See also:
         # - http://msdn2.microsoft.com/en-us/library/y0zzbyt4.aspx
         linkflags += [
             '/fixed:no',
             '/incremental:no',
         ]
     env.Append(LINKFLAGS = linkflags)
     env.Append(SHLINKFLAGS = shlinkflags)

     # We have C++ in several libraries, so always link with the C++ compiler
     if gcc_compat:
         env['LINK'] = env['CXX']

     # Default libs
     libs = []
     if env['platform'] in ('darwin', 'freebsd', 'linux', 'posix', 'sunos'):
         libs += ['m', 'pthread', 'dl']
     if env['platform'] in ('linux',):
         libs += ['rt']
     env.Append(LIBS = libs)

     # OpenMP
     if env['openmp']:
         if env['msvc']:
             env.Append(CCFLAGS = ['/openmp'])
             # When building openmp release VS2008 link.exe crashes with LNK1103 error.
             # Workaround: overwrite PDB flags with empty value as it isn't required anyways
             if env['build'] == 'release':
                 env['PDB'] = ''
         if env['gcc']:
             env.Append(CCFLAGS = ['-fopenmp'])
             env.Append(LIBS = ['gomp'])

     # Load tools
     env.Tool('lex')
     env.Tool('yacc')
     if env['llvm']:
         env.Tool('llvm')

     # Custom builders and methods
     env.Tool('custom')
     createInstallMethods(env)

     env.PkgCheckModules('X11', ['x11', 'xext', 'xdamage', 'xfixes'])
     env.PkgCheckModules('XCB', ['x11-xcb', 'xcb-glx >= 1.8.1'])
     env.PkgCheckModules('XF86VIDMODE', ['xxf86vm'])
     env.PkgCheckModules('DRM', ['libdrm >= 2.4.24'])
     env.PkgCheckModules('DRM_INTEL', ['libdrm_intel >= 2.4.30'])
     env.PkgCheckModules('DRM_RADEON', ['libdrm_radeon >= 2.4.42'])
     env.PkgCheckModules('XORG', ['xorg-server >= 1.6.0'])
     env.PkgCheckModules('KMS', ['libkms >= 2.4.24'])
     env.PkgCheckModules('UDEV', ['libudev > 150'])

     env['dri'] = env['x11'] and env['drm']

     # for debugging
     #print env.Dump()


 def exists(env):
     return 1
	"""gallium

	Frontend-tool for Gallium3D architecture.

	"""

	#
	# Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas.
	# All Rights Reserved.
	#
	# Permission is hereby granted, free of charge, to any person obtaining a
	# copy of this software and associated documentation files (the
	# "Software"), to deal in the Software without restriction, including
	# without limitation the rights to use, copy, modify, merge, publish,
	# distribute, sub license, and/or sell copies of the Software, and to
	# permit persons to whom the Software is furnished to do so, subject to
	# the following conditions:
	#
	# The above copyright notice and this permission notice (including the
	# next paragraph) shall be included in all copies or substantial portions
	# of the Software.
	#
	# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
	# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
	# IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
	# ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
	# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
	# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
	#


	import distutils.version
	import os
	import os.path
	import re
	import subprocess
	import platform as _platform

	import SCons.Action
	import SCons.Builder
	import SCons.Scanner


	def symlink(target, source, env):
	target = str(target[0])
	source = str(source[0])
	if os.path.islink(target) or os.path.exists(target):
	os.remove(target)
	os.symlink(os.path.basename(source), target)

	def install(env, source, subdir):
	target_dir = os.path.join(env.Dir('#.').srcnode().abspath, env['build_dir'], subdir)
	return env.Install(target_dir, source)

	def install_program(env, source):
	return install(env, source, 'bin')

	def install_shared_library(env, sources, version = ()):
	targets = []
	install_dir = os.path.join(env.Dir('#.').srcnode().abspath, env['build_dir'])
	version = tuple(map(str, version))
	if env['SHLIBSUFFIX'] == '.dll':
	dlls = env.FindIxes(sources, 'SHLIBPREFIX', 'SHLIBSUFFIX')
	targets += install(env, dlls, 'bin')
	libs = env.FindIxes(sources, 'LIBPREFIX', 'LIBSUFFIX')
	targets += install(env, libs, 'lib')
	else:
	for source in sources:
	target_dir = os.path.join(install_dir, 'lib')
	target_name = '.'.join((str(source),) + version)
	last = env.InstallAs(os.path.join(target_dir, target_name), source)
	targets += last
	while len(version):
	version = version[:-1]
	target_name = '.'.join((str(source),) + version)
	action = SCons.Action.Action(symlink, " Symlinking $TARGET ...")
	last = env.Command(os.path.join(target_dir, target_name), last, action)
	targets += last
	return targets


	def createInstallMethods(env):
	env.AddMethod(install_program, 'InstallProgram')
	env.AddMethod(install_shared_library, 'InstallSharedLibrary')


	def num_jobs():
	try:
	return int(os.environ['NUMBER_OF_PROCESSORS'])
	except (ValueError, KeyError):
	pass

	try:
	return os.sysconf('SC_NPROCESSORS_ONLN')
	except (ValueError, OSError, AttributeError):
	pass

	try:
	return int(os.popen2("sysctl -n hw.ncpu")[1].read())
	except ValueError:
	pass

	return 1


	def generate(env):
	"""Common environment generation code"""

	# Tell tools which machine to compile for
	env['TARGET_ARCH'] = env['machine']
	env['MSVS_ARCH'] = env['machine']

	# Toolchain
	platform = env['platform']
	env.Tool(env['toolchain'])

	# Allow override compiler and specify additional flags from environment
	if os.environ.has_key('CC'):
	env['CC'] = os.environ['CC']
	# Update CCVERSION to match
	pipe = SCons.Action._subproc(env, [env['CC'], '--version'],
	stdin = 'devnull',
	stderr = 'devnull',
	stdout = subprocess.PIPE)
	if pipe.wait() == 0:
	line = pipe.stdout.readline()
	match = re.search(r'[0-9]+(\.[0-9]+)+', line)
	if match:
	env['CCVERSION'] = match.group(0)
	if os.environ.has_key('CFLAGS'):
	env['CCFLAGS'] += SCons.Util.CLVar(os.environ['CFLAGS'])
	if os.environ.has_key('CXX'):
	env['CXX'] = os.environ['CXX']
	if os.environ.has_key('CXXFLAGS'):
	env['CXXFLAGS'] += SCons.Util.CLVar(os.environ['CXXFLAGS'])
	if os.environ.has_key('LDFLAGS'):
	env['LINKFLAGS'] += SCons.Util.CLVar(os.environ['LDFLAGS'])

	env['gcc'] = 'gcc' in os.path.basename(env['CC']).split('-')
	env['msvc'] = env['CC'] == 'cl'
	env['suncc'] = env['platform'] == 'sunos' and os.path.basename(env['CC']) == 'cc'
	env['clang'] = env['CC'] == 'clang'
	env['icc'] = 'icc' == os.path.basename(env['CC'])

	if env['msvc'] and env['toolchain'] == 'default' and env['machine'] == 'x86_64':
	# MSVC x64 support is broken in earlier versions of scons
	env.EnsurePythonVersion(2, 0)

	# shortcuts
	machine = env['machine']
	platform = env['platform']
	x86 = env['machine'] == 'x86'
	ppc = env['machine'] == 'ppc'
	gcc_compat = env['gcc'] or env['clang']
	msvc = env['msvc']
	suncc = env['suncc']
	icc = env['icc']

	# Determine whether we are cross compiling; in particular, whether we need
	# to compile code generators with a different compiler as the target code.
	host_platform = _platform.system().lower()
	if host_platform.startswith('cygwin'):
	host_platform = 'cygwin'
	host_machine = os.environ.get('PROCESSOR_ARCHITEW6432', os.environ.get('PROCESSOR_ARCHITECTURE', _platform.machine()))
	host_machine = {
	'x86': 'x86',
	'i386': 'x86',
	'i486': 'x86',
	'i586': 'x86',
	'i686': 'x86',
	'ppc' : 'ppc',
	'AMD64': 'x86_64',
	'x86_64': 'x86_64',
	}.get(host_machine, 'generic')
	env['crosscompile'] = platform != host_platform
	if machine == 'x86_64' and host_machine != 'x86_64':
	env['crosscompile'] = True
	env['hostonly'] = False

	# Backwards compatability with the debug= profile= options
	if env['build'] == 'debug':
	if not env['debug']:
	print 'scons: warning: debug option is deprecated and will be removed eventually; use instead'
	print
	print ' scons build=release'
	print
	env['build'] = 'release'
	if env['profile']:
	print 'scons: warning: profile option is deprecated and will be removed eventually; use instead'
	print
	print ' scons build=profile'
	print
	env['build'] = 'profile'
	if False:
	# Enforce SConscripts to use the new build variable
	env.popitem('debug')
	env.popitem('profile')
	else:
	# Backwards portability with older sconscripts
	if env['build'] in ('debug', 'checked'):
	env['debug'] = True
	env['profile'] = False
	if env['build'] == 'profile':
	env['debug'] = False
	env['profile'] = True
	if env['build'] == 'release':
	env['debug'] = False
	env['profile'] = False

	# Put build output in a separate dir, which depends on the current
	# configuration. See also http://www.scons.org/wiki/AdvancedBuildExample
	build_topdir = 'build'
	build_subdir = env['platform']
	if env['embedded']:
	build_subdir = 'embedded-' + build_subdir
	if env['machine'] != 'generic':
	build_subdir += '-' + env['machine']
	if env['build'] != 'release':
	build_subdir += '-' + env['build']
	build_dir = os.path.join(build_topdir, build_subdir)
	# Place the .sconsign file in the build dir too, to avoid issues with
	# different scons versions building the same source file
	env['build_dir'] = build_dir
	env.SConsignFile(os.path.join(build_dir, '.sconsign'))
	if 'SCONS_CACHE_DIR' in os.environ:
	print 'scons: Using build cache in %s.' % (os.environ['SCONS_CACHE_DIR'],)
	env.CacheDir(os.environ['SCONS_CACHE_DIR'])
	env['CONFIGUREDIR'] = os.path.join(build_dir, 'conf')
	env['CONFIGURELOG'] = os.path.join(os.path.abspath(build_dir), 'config.log')

	# Parallel build
	if env.GetOption('num_jobs') <= 1:
	env.SetOption('num_jobs', num_jobs())

	env.Decider('MD5-timestamp')
	env.SetOption('max_drift', 60)

	# C preprocessor options
	cppdefines = []
	if env['build'] in ('debug', 'checked'):
	cppdefines += ['DEBUG']
	else:
	cppdefines += ['NDEBUG']
	if env['build'] == 'profile':
	cppdefines += ['PROFILE']
	if env['platform'] in ('posix', 'linux', 'freebsd', 'darwin'):
	cppdefines += [
	'_POSIX_SOURCE',
	('_POSIX_C_SOURCE', '199309L'),
	'_SVID_SOURCE',
	'_BSD_SOURCE',
	'_GNU_SOURCE',
	'HAVE_PTHREAD',
	'HAVE_POSIX_MEMALIGN',
	]
	if env['platform'] == 'darwin':
	cppdefines += [
	'_DARWIN_C_SOURCE',
	'GLX_USE_APPLEGL',
	'GLX_DIRECT_RENDERING',
	]
	else:
	cppdefines += [
	'GLX_DIRECT_RENDERING',
	'GLX_INDIRECT_RENDERING',
	]
	if env['platform'] in ('linux', 'freebsd'):
	cppdefines += ['HAVE_ALIAS']
	else:
	cppdefines += ['GLX_ALIAS_UNSUPPORTED']
	if platform == 'windows':
	cppdefines += [
	'WIN32',
	'_WINDOWS',
	#'_UNICODE',
	#'UNICODE',
	# http://msdn.microsoft.com/en-us/library/aa383745.aspx
	('_WIN32_WINNT', '0x0601'),
	('WINVER', '0x0601'),
	]
	if gcc_compat:
	cppdefines += [('__MSVCRT_VERSION__', '0x0700')]
	if msvc:
	cppdefines += [
	'VC_EXTRALEAN',
	'_USE_MATH_DEFINES',
	'_CRT_SECURE_NO_WARNINGS',
	'_CRT_SECURE_NO_DEPRECATE',
	'_SCL_SECURE_NO_WARNINGS',
	'_SCL_SECURE_NO_DEPRECATE',
	'_ALLOW_KEYWORD_MACROS',
	]
	if env['build'] in ('debug', 'checked'):
	cppdefines += ['_DEBUG']
	if platform == 'windows':
	cppdefines += ['PIPE_SUBSYSTEM_WINDOWS_USER']
	if platform == 'haiku':
	cppdefines += ['BEOS_THREADS']
	if env['embedded']:
	cppdefines += ['PIPE_SUBSYSTEM_EMBEDDED']
	if env['texture_float']:
	print 'warning: Floating-point textures enabled.'
	print 'warning: Please consult docs/patents.txt with your lawyer before building Mesa.'
	cppdefines += ['TEXTURE_FLOAT_ENABLED']
	env.Append(CPPDEFINES = cppdefines)

	# C compiler options
	cflags = [] # C
	cxxflags = [] # C++
	ccflags = [] # C & C++
	if gcc_compat:
	ccversion = env['CCVERSION']
	if env['build'] == 'debug':
	ccflags += ['-O0']
	elif env['gcc'] and ccversion.startswith('4.2.'):
	# gcc 4.2.x optimizer is broken
	print "warning: gcc 4.2.x optimizer is broken -- disabling optimizations"
	ccflags += ['-O0']
	else:
	ccflags += ['-O3']
	if env['gcc']:
	# gcc's builtin memcmp is slower than glibc's
	# http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43052
	ccflags += ['-fno-builtin-memcmp']
	# Work around aliasing bugs - developers should comment this out
	ccflags += ['-fno-strict-aliasing']
	ccflags += ['-g']
	if env['build'] in ('checked', 'profile'):
	# See http://code.google.com/p/jrfonseca/wiki/Gprof2Dot#Which_options_should_I_pass_to_gcc_when_compiling_for_profiling?
	ccflags += [
	'-fno-omit-frame-pointer',
	]
	if env['gcc']:
	ccflags += ['-fno-optimize-sibling-calls']
	if env['machine'] == 'x86':
	ccflags += [
	'-m32',
	#'-march=pentium4',
	]
	if distutils.version.LooseVersion(ccversion) >= distutils.version.LooseVersion('4.2') \
	and (platform != 'windows' or env['build'] == 'debug' or True) \
	and platform != 'haiku':
	# NOTE: We need to ensure stack is realigned given that we
	# produce shared objects, and have no control over the stack
	# alignment policy of the application. Therefore we need
	# -mstackrealign ore -mincoming-stack-boundary=2.
	#
	# XXX: -O and -mstackrealign causes stack corruption on MinGW
	#
	# XXX: We could have SSE without -mstackrealign if we always used
	# __attribute__((force_align_arg_pointer)), but that's not
	# always the case.
	ccflags += [
	'-mstackrealign', # ensure stack is aligned
	'-mmmx', '-msse', '-msse2', # enable SIMD intrinsics
	#'-mfpmath=sse',
	]
	if platform in ['windows', 'darwin']:
	# Workaround http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37216
	ccflags += ['-fno-common']
	if platform in ['haiku']:
	# Make optimizations compatible with Pentium or higher on Haiku
	ccflags += [
	'-mstackrealign', # ensure stack is aligned
	'-march=i586', # Haiku target is Pentium
	'-mtune=i686' # use i686 where we can
	]
	if env['machine'] == 'x86_64':
	ccflags += ['-m64']
	if platform == 'darwin':
	ccflags += ['-fno-common']
	if env['platform'] not in ('cygwin', 'haiku', 'windows'):
	ccflags += ['-fvisibility=hidden']
	# See also:
	# - http://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html
	ccflags += [
	'-Wall',
	'-Wno-long-long',
	'-fmessage-length=0', # be nice to Eclipse
	]
	cflags += [
	'-Wmissing-prototypes',
	'-std=gnu99',
	]
	if distutils.version.LooseVersion(ccversion) >= distutils.version.LooseVersion('4.2'):
	ccflags += [
	'-Wpointer-arith',
	]
	cflags += [
	'-Wdeclaration-after-statement',
	]
	if icc:
	cflags += [
	'-std=gnu99',
	]
	if msvc:
	# See also:
	# - http://msdn.microsoft.com/en-us/library/19z1t1wy.aspx
	# - cl /?
	if env['build'] == 'debug':
	ccflags += [
	'/Od', # disable optimizations
	'/Oi', # enable intrinsic functions
	]
	else:
	if 'MSVC_VERSION' in env and distutils.version.LooseVersion(env['MSVC_VERSION']) < distutils.version.LooseVersion('11.0'):
	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 )'
	ccflags += [
	'/O2', # optimize for speed
	]
	if env['build'] == 'release':
	ccflags += [
	'/GL', # enable whole program optimization
	]
	else:
	ccflags += [
	'/Oy-', # disable frame pointer omission
	'/GL-', # disable whole program optimization
	]
	ccflags += [
	'/W3', # warning level
	#'/Wp64', # enable 64 bit porting warnings
	'/wd4996', # disable deprecated POSIX name warnings
	]
	if env['machine'] == 'x86':
	ccflags += [
	#'/arch:SSE2', # use the SSE2 instructions
	]
	if platform == 'windows':
	ccflags += [
	# TODO
	]
	# Automatic pdb generation
	# See http://scons.tigris.org/issues/show_bug.cgi?id=1656
	env.EnsureSConsVersion(0, 98, 0)
	env['PDB'] = '${TARGET.base}.pdb'
	env.Append(CCFLAGS = ccflags)
	env.Append(CFLAGS = cflags)
	env.Append(CXXFLAGS = cxxflags)

	if env['platform'] == 'windows' and msvc:
	# Choose the appropriate MSVC CRT
	# http://msdn.microsoft.com/en-us/library/2kzt1wy3.aspx
	if env['build'] in ('debug', 'checked'):
	env.Append(CCFLAGS = ['/MTd'])
	env.Append(SHCCFLAGS = ['/LDd'])
	else:
	env.Append(CCFLAGS = ['/MT'])
	env.Append(SHCCFLAGS = ['/LD'])

	# Assembler options
	if gcc_compat:
	if env['machine'] == 'x86':
	env.Append(ASFLAGS = ['-m32'])
	if env['machine'] == 'x86_64':
	env.Append(ASFLAGS = ['-m64'])

	# Linker options
	linkflags = []
	shlinkflags = []
	if gcc_compat:
	if env['machine'] == 'x86':
	linkflags += ['-m32']
	if env['machine'] == 'x86_64':
	linkflags += ['-m64']
	if env['platform'] not in ('darwin'):
	shlinkflags += [
	'-Wl,-Bsymbolic',
	]
	# Handle circular dependencies in the libraries
	if env['platform'] in ('darwin'):
	pass
	else:
	env['_LIBFLAGS'] = '-Wl,--start-group ' + env['_LIBFLAGS'] + ' -Wl,--end-group'
	if env['platform'] == 'windows':
	# Avoid depending on gcc runtime DLLs
	linkflags += ['-static-libgcc']
	if 'w64' in env['CC'].split('-'):
	linkflags += ['-static-libstdc++']
	# Handle the @xx symbol munging of DLL exports
	shlinkflags += ['-Wl,--enable-stdcall-fixup']
	#shlinkflags += ['-Wl,--kill-at']
	if msvc:
	if env['build'] == 'release':
	# enable Link-time Code Generation
	linkflags += ['/LTCG']
	env.Append(ARFLAGS = ['/LTCG'])
	if platform == 'windows' and msvc:
	# See also:
	# - http://msdn2.microsoft.com/en-us/library/y0zzbyt4.aspx
	linkflags += [
	'/fixed:no',
	'/incremental:no',
	]
	env.Append(LINKFLAGS = linkflags)
	env.Append(SHLINKFLAGS = shlinkflags)

	# We have C++ in several libraries, so always link with the C++ compiler
	if gcc_compat:
	env['LINK'] = env['CXX']

	# Default libs
	libs = []
	if env['platform'] in ('darwin', 'freebsd', 'linux', 'posix', 'sunos'):
	libs += ['m', 'pthread', 'dl']
	if env['platform'] in ('linux',):
	libs += ['rt']
	env.Append(LIBS = libs)

	# OpenMP
	if env['openmp']:
	if env['msvc']:
	env.Append(CCFLAGS = ['/openmp'])
	# When building openmp release VS2008 link.exe crashes with LNK1103 error.
	# Workaround: overwrite PDB flags with empty value as it isn't required anyways
	if env['build'] == 'release':
	env['PDB'] = ''
	if env['gcc']:
	env.Append(CCFLAGS = ['-fopenmp'])
	env.Append(LIBS = ['gomp'])

	# Load tools
	env.Tool('lex')
	env.Tool('yacc')
	if env['llvm']:
	env.Tool('llvm')

	# Custom builders and methods
	env.Tool('custom')
	createInstallMethods(env)

	env.PkgCheckModules('X11', ['x11', 'xext', 'xdamage', 'xfixes'])
	env.PkgCheckModules('XCB', ['x11-xcb', 'xcb-glx >= 1.8.1'])
	env.PkgCheckModules('XF86VIDMODE', ['xxf86vm'])
	env.PkgCheckModules('DRM', ['libdrm >= 2.4.24'])
	env.PkgCheckModules('DRM_INTEL', ['libdrm_intel >= 2.4.30'])
	env.PkgCheckModules('DRM_RADEON', ['libdrm_radeon >= 2.4.42'])
	env.PkgCheckModules('XORG', ['xorg-server >= 1.6.0'])
	env.PkgCheckModules('KMS', ['libkms >= 2.4.24'])
	env.PkgCheckModules('UDEV', ['libudev > 150'])

	env['dri'] = env['x11'] and env['drm']

	# for debugging
	#print env.Dump()


	def exists(env):
	return 1