scons/generic.py - third_party/mesa - Git at Google

 """generic

 Generic tool that provides a commmon ground for all platforms.

 """

 #
 # 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 os
 import os.path
 import re
 import platform as _platform
 import sys

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


 def quietCommandLines(env):
     # Quiet command lines
     # See also http://www.scons.org/wiki/HidingCommandLinesInOutput
     env['CCCOMSTR'] = "Compiling $SOURCE ..."
     env['CXXCOMSTR'] = "Compiling $SOURCE ..."
     env['ARCOMSTR'] = "Archiving $TARGET ..."
     env['RANLIBCOMSTR'] = ""
     env['LINKCOMSTR'] = "Linking $TARGET ..."


 def createConvenienceLibBuilder(env):
     """This is a utility function that creates the ConvenienceLibrary
     Builder in an Environment if it is not there already.

     If it is already there, we return the existing one.

     Based on the stock StaticLibrary and SharedLibrary builders.
     """

     try:
         convenience_lib = env['BUILDERS']['ConvenienceLibrary']
     except KeyError:
         action_list = [ SCons.Action.Action("$ARCOM", "$ARCOMSTR") ]
         if env.Detect('ranlib'):
             ranlib_action = SCons.Action.Action("$RANLIBCOM", "$RANLIBCOMSTR")
             action_list.append(ranlib_action)

         convenience_lib = SCons.Builder.Builder(action = action_list,
                                   emitter = '$LIBEMITTER',
                                   prefix = '$LIBPREFIX',
                                   suffix = '$LIBSUFFIX',
                                   src_suffix = '$SHOBJSUFFIX',
                                   src_builder = 'SharedObject')
         env['BUILDERS']['ConvenienceLibrary'] = convenience_lib

     return convenience_lib


 # TODO: handle import statements with multiple modules
 # TODO: handle from import statements
 import_re = re.compile(r'^import\s+(\S+)$', re.M)

 def python_scan(node, env, path):
     # http://www.scons.org/doc/0.98.5/HTML/scons-user/c2781.html#AEN2789
     contents = node.get_contents()
     source_dir = node.get_dir()
     imports = import_re.findall(contents)
     results = []
     for imp in imports:
         for dir in path:
             file = os.path.join(str(dir), imp.replace('.', os.sep) + '.py')
             if os.path.exists(file):
                 results.append(env.File(file))
                 break
             file = os.path.join(str(dir), imp.replace('.', os.sep), '__init__.py')
             if os.path.exists(file):
                 results.append(env.File(file))
                 break
     return results

 python_scanner = SCons.Scanner.Scanner(function = python_scan, skeys = ['.py'])


 def code_generate(env, script, target, source, command):
     """Method to simplify code generation via python scripts.

     http://www.scons.org/wiki/UsingCodeGenerators
     http://www.scons.org/doc/0.98.5/HTML/scons-user/c2768.html
     """

     # We're generating code using Python scripts, so we have to be
     # careful with our scons elements.  This entry represents
     # the generator file *in the source directory*.
     script_src = env.File(script).srcnode()

     # This command creates generated code *in the build directory*.
     command = command.replace('$SCRIPT', script_src.path)
     code = env.Command(target, source, command)

     # Explicitly mark that the generated code depends on the generator,
     # and on implicitly imported python modules
     path = (script_src.get_dir(),)
     deps = [script_src]
     deps += script_src.get_implicit_deps(env, python_scanner, path)
     env.Depends(code, deps)

     # Running the Python script causes .pyc files to be generated in the
     # source directory.  When we clean up, they should go too. So add side
     # effects for .pyc files
     for dep in deps:
         pyc = env.File(str(dep) + 'c')
         env.SideEffect(pyc, code)

     return code


 def createCodeGenerateMethod(env):
     env.Append(SCANNERS = python_scanner)
     env.AddMethod(code_generate, 'CodeGenerate')


 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_shared_library(env, source, version = ()):
     source = str(source[0])
     version = tuple(map(str, version))
     target_dir =  os.path.join(env.Dir('#.').srcnode().abspath, env['build'], 'lib')
     target_name = '.'.join((str(source),) + version)
     last = env.InstallAs(os.path.join(target_dir, target_name), source)
     while len(version):
         version = version[:-1]
         target_name = '.'.join((str(source),) + version)
         action = SCons.Action.Action(symlink, "$TARGET -> $SOURCE")
         last = env.Command(os.path.join(target_dir, target_name), last, action)

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


 _platform_map = {
     'linux2': 'linux',
     'win32': 'windows',
 }


 _machine_map = {
 	'x86': 'x86',
 	'i386': 'x86',
 	'i486': 'x86',
 	'i586': 'x86',
 	'i686': 'x86',
 	'ppc': 'ppc',
 	'x86_64': 'x86_64',
 }


 _toolchain_map = {
     'winddk': 'winddk',
     'wince': 'wcesdk',
 }


 _bool_map = {
     'y': 1,
     'yes': 1,
     't': 1,
     'true': 1,
     '1': 1,
     'on': 1,
     'all': 1,
     'n': 0,
     'no': 0,
     'f': 0,
     'false': 0,
     '0': 0,
     'off': 0,
     'none': 0,
 }


 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"""

     from SCons.Script import ARGUMENTS

     # FIXME: this is already too late
     #if env.get('quiet', False):
     #    quietCommandLines(env)


     # Platform
     try:
         env['platform'] = ARGUMENTS['platform']
     except KeyError:
         env['platform'] = _platform_map.get(sys.platform, sys.platform)

     # Machine
     try:
         env['machine'] = ARGUMENTS['machine']
     except KeyError:
         env['machine'] = _machine_map.get(os.environ.get('PROCESSOR_ARCHITECTURE', _platform.machine()), 'generic')

     # Toolchain
     try:
         env['toolchain'] = ARGUMENTS['toolchain']
     except KeyError:
         if env['platform'] in ('windows', 'winddk', 'wince') and sys.platform != 'win32':
             env['toolchain'] = 'crossmingw'
         else:
             env['toolchain'] = _toolchain_map.get(env['platform'], 'default')
     if env['toolchain'] == 'crossmingw' and env['machine'] not in ('generic', 'x86'):
             env['machine'] = 'x86'

     try:
         env['MSVS_VERSION'] = ARGUMENTS['MSVS_VERSION']
     except KeyError:
         pass

     # Build type
     env['debug'] = _bool_map[ARGUMENTS.get('debug', 'no')]
     env['profile'] = _bool_map[ARGUMENTS.get('profile', 'no')]

     # Put build output in a separate dir, which depends on the current
     # configuration. See also http://www.scons.org/wiki/AdvancedBuildExample
     try:
         env['build'] = ARGUMENTS['build']
     except KeyError:
         build_topdir = 'build'
         build_subdir = env['platform']
         if env['machine'] != 'generic':
             build_subdir += '-' + env['machine']
         if env['debug']:
             build_subdir += "-debug"
         if env['profile']:
             build_subdir += "-profile"
         env['build'] = 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.SConsignFile(os.path.join(env['build'], '.sconsign'))

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

     # Summary
     print
     print '  platform=%s' % env['platform']
     print '  machine=%s' % env['machine']
     print '  toolchain=%s' % env['toolchain']
     print '  debug=%s' % ['no', 'yes'][env['debug']]
     print '  profile=%s' % ['no', 'yes'][env['profile']]
     print '  build=%s' % env['build']
     print '  %s jobs' % env.GetOption('num_jobs')
     print

     # Load tool chain
     env.Tool(env['toolchain'])

     env['gcc'] = 'gcc' in os.path.basename(env['CC']).split('-')
     env['msvc'] = env['CC'] == 'cl'

     # shortcuts
     debug = env['debug']
     machine = env['machine']
     platform = env['platform']
     x86 = env['machine'] == 'x86'
     ppc = env['machine'] == 'ppc'
     gcc = env['gcc']
     msvc = env['msvc']

     # C preprocessor options
     cppdefines = []
     if debug:
         cppdefines += ['DEBUG']
     else:
         cppdefines += ['NDEBUG']
     if env['profile']:
         cppdefines += ['PROFILE']
     if platform == 'windows':
         cppdefines += [
             'WIN32',
             '_WINDOWS',
             #'_UNICODE',
             #'UNICODE',
             # http://msdn2.microsoft.com/en-us/library/6dwk3a1z.aspx,
             #'WIN32_LEAN_AND_MEAN',
         ]
         if msvc:
             cppdefines += [
                 'VC_EXTRALEAN',
                 '_USE_MATH_DEFINES',
                 '_CRT_SECURE_NO_DEPRECATE',
             ]
         if debug:
             cppdefines += ['_DEBUG']
     if platform == 'winddk':
         # Mimic WINDDK's builtin flags. See also:
         # - WINDDK's bin/makefile.new i386mk.inc for more info.
         # - buildchk_wxp_x86.log files, generated by the WINDDK's build
         # - http://alter.org.ua/docs/nt_kernel/vc8_proj/
         cppdefines += [
             ('_X86_', '1'),
             ('i386', '1'),
             'STD_CALL',
             ('CONDITION_HANDLING', '1'),
             ('NT_INST', '0'),
             ('WIN32', '100'),
             ('_NT1X_', '100'),
             ('WINNT', '1'),
             ('_WIN32_WINNT', '0x0501'), # minimum required OS version
             ('WINVER', '0x0501'),
             ('_WIN32_IE', '0x0603'),
             ('WIN32_LEAN_AND_MEAN', '1'),
             ('DEVL', '1'),
             ('__BUILDMACHINE__', 'WinDDK'),
             ('FPO', '0'),
         ]
         if debug:
             cppdefines += [('DBG', 1)]
     if platform == 'wince':
         cppdefines += [
             '_CRT_SECURE_NO_DEPRECATE',
             '_USE_32BIT_TIME_T',
             'UNICODE',
             '_UNICODE',
             ('UNDER_CE', '600'),
             ('_WIN32_WCE', '0x600'),
             'WINCEOEM',
             'WINCEINTERNAL',
             'WIN32',
             'STRICT',
             'x86',
             '_X86_',
             'INTERNATIONAL',
             ('INTLMSG_CODEPAGE', '1252'),
         ]
     env.Append(CPPDEFINES = cppdefines)

     # C preprocessor includes
     if platform == 'winddk':
         env.Append(CPPPATH = [
             env['SDK_INC_PATH'],
             env['DDK_INC_PATH'],
             env['WDM_INC_PATH'],
             env['CRT_INC_PATH'],
         ])

     # C compiler options
     cflags = [] # C
     cxxflags = [] # C++
     ccflags = [] # C & C++
     if gcc:
         if debug:
             ccflags += ['-O0', '-g3']
         elif env['toolchain'] == 'crossmingw':
             ccflags += ['-O0', '-g3'] # mingw 4.2.1 optimizer is broken
         else:
             ccflags += ['-O3', '-g0']
         if env['profile']:
             ccflags += ['-pg']
         if env['machine'] == 'x86':
             ccflags += [
                 '-m32',
                 #'-march=pentium4',
                 '-mmmx', '-msse', '-msse2', # enable SIMD intrinsics
                 #'-mfpmath=sse',
             ]
         if env['machine'] == 'x86_64':
             ccflags += ['-m64']
         # See also:
         # - http://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html
         ccflags += [
             '-Wall',
             '-Wmissing-field-initializers',
             '-Wpointer-arith',
             '-Wno-long-long',
             '-ffast-math',
             '-fmessage-length=0', # be nice to Eclipse
         ]
         cflags += [
             '-Werror=declaration-after-statement',
             '-Wmissing-prototypes',
             '-std=gnu99',
         ]
     if msvc:
         # See also:
         # - http://msdn.microsoft.com/en-us/library/19z1t1wy.aspx
         # - cl /?
         if debug:
             ccflags += [
               '/Od', # disable optimizations
               '/Oi', # enable intrinsic functions
               '/Oy-', # disable frame pointer omission
               '/GL-', # disable whole program optimization
             ]
         else:
             ccflags += [
               '/Ox', # maximum optimizations
               '/Oi', # enable intrinsic functions
               '/Ot', # favor code speed
               #'/fp:fast', # fast floating point
             ]
         if env['profile']:
             ccflags += [
                 '/Gh', # enable _penter hook function
                 '/GH', # enable _pexit hook function
             ]
         ccflags += [
             '/W3', # warning level
             #'/Wp64', # enable 64 bit porting warnings
         ]
         if env['machine'] == 'x86':
             ccflags += [
                 #'/QIfist', # Suppress _ftol
                 #'/arch:SSE2', # use the SSE2 instructions
             ]
         if platform == 'windows':
             ccflags += [
                 # TODO
             ]
         if platform == 'winddk':
             ccflags += [
                 '/Zl', # omit default library name in .OBJ
                 '/Zp8', # 8bytes struct member alignment
                 '/Gy', # separate functions for linker
                 '/Gm-', # disable minimal rebuild
                 '/WX', # treat warnings as errors
                 '/Gz', # __stdcall Calling convention
                 '/GX-', # disable C++ EH
                 '/GR-', # disable C++ RTTI
                 '/GF', # enable read-only string pooling
                 '/G6', # optimize for PPro, P-II, P-III
                 '/Ze', # enable extensions
                 '/Gi-', # disable incremental compilation
                 '/QIfdiv-', # disable Pentium FDIV fix
                 '/hotpatch', # prepares an image for hotpatching.
                 #'/Z7', #enable old-style debug info
             ]
         if platform == 'wince':
             # See also C:\WINCE600\public\common\oak\misc\makefile.def
             ccflags += [
                 '/Zl', # omit default library name in .OBJ
                 '/GF', # enable read-only string pooling
                 '/GR-', # disable C++ RTTI
                 '/GS', # enable security checks
                 # Allow disabling language conformance to maintain backward compat
                 #'/Zc:wchar_t-', # don't force wchar_t as native type, instead of typedef
                 #'/Zc:forScope-', # don't enforce Standard C++ for scoping rules
                 #'/wd4867',
                 #'/wd4430',
                 #'/MT',
                 #'/U_MT',
             ]
         # 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['debug']:
             env.Append(CCFLAGS = ['/MTd'])
             env.Append(SHCCFLAGS = ['/LDd'])
         else:
             env.Append(CCFLAGS = ['/MT'])
             env.Append(SHCCFLAGS = ['/LD'])

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

     # Linker options
     linkflags = []
     if gcc:
         if env['machine'] == 'x86':
             linkflags += ['-m32']
         if env['machine'] == 'x86_64':
             linkflags += ['-m64']
     if platform == 'windows' and msvc:
         # See also:
         # - http://msdn2.microsoft.com/en-us/library/y0zzbyt4.aspx
         linkflags += [
             '/fixed:no',
             '/incremental:no',
         ]
     if platform == 'winddk':
         linkflags += [
             '/merge:_PAGE=PAGE',
             '/merge:_TEXT=.text',
             '/section:INIT,d',
             '/opt:ref',
             '/opt:icf',
             '/ignore:4198,4010,4037,4039,4065,4070,4078,4087,4089,4221',
             '/incremental:no',
             '/fullbuild',
             '/release',
             '/nodefaultlib',
             '/wx',
             '/debug',
             '/debugtype:cv',
             '/version:5.1',
             '/osversion:5.1',
             '/functionpadmin:5',
             '/safeseh',
             '/pdbcompress',
             '/stack:0x40000,0x1000',
             '/driver',
             '/align:0x80',
             '/subsystem:native,5.01',
             '/base:0x10000',

             '/entry:DrvEnableDriver',
         ]
         if env['debug'] or env['profile']:
             linkflags += [
                 '/MAP', # http://msdn.microsoft.com/en-us/library/k7xkk3e2.aspx
             ]
     if platform == 'wince':
         linkflags += [
             '/nodefaultlib',
             #'/incremental:no',
             #'/fullbuild',
             '/entry:_DllMainCRTStartup',
         ]
     env.Append(LINKFLAGS = linkflags)

     # Default libs
     env.Append(LIBS = [])

     # Custom builders and methods
     createConvenienceLibBuilder(env)
     createCodeGenerateMethod(env)
     createInstallMethods(env)

     # for debugging
     #print env.Dump()


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

	Generic tool that provides a commmon ground for all platforms.

	"""

	#
	# 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 os
	import os.path
	import re
	import platform as _platform
	import sys

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


	def quietCommandLines(env):
	# Quiet command lines
	# See also http://www.scons.org/wiki/HidingCommandLinesInOutput
	env['CCCOMSTR'] = "Compiling $SOURCE ..."
	env['CXXCOMSTR'] = "Compiling $SOURCE ..."
	env['ARCOMSTR'] = "Archiving $TARGET ..."
	env['RANLIBCOMSTR'] = ""
	env['LINKCOMSTR'] = "Linking $TARGET ..."


	def createConvenienceLibBuilder(env):
	"""This is a utility function that creates the ConvenienceLibrary
	Builder in an Environment if it is not there already.

	If it is already there, we return the existing one.

	Based on the stock StaticLibrary and SharedLibrary builders.
	"""

	try:
	convenience_lib = env['BUILDERS']['ConvenienceLibrary']
	except KeyError:
	action_list = [ SCons.Action.Action("$ARCOM", "$ARCOMSTR") ]
	if env.Detect('ranlib'):
	ranlib_action = SCons.Action.Action("$RANLIBCOM", "$RANLIBCOMSTR")
	action_list.append(ranlib_action)

	convenience_lib = SCons.Builder.Builder(action = action_list,
	emitter = '$LIBEMITTER',
	prefix = '$LIBPREFIX',
	suffix = '$LIBSUFFIX',
	src_suffix = '$SHOBJSUFFIX',
	src_builder = 'SharedObject')
	env['BUILDERS']['ConvenienceLibrary'] = convenience_lib

	return convenience_lib


	# TODO: handle import statements with multiple modules
	# TODO: handle from import statements
	import_re = re.compile(r'^import\s+(\S+)$', re.M)

	def python_scan(node, env, path):
	# http://www.scons.org/doc/0.98.5/HTML/scons-user/c2781.html#AEN2789
	contents = node.get_contents()
	source_dir = node.get_dir()
	imports = import_re.findall(contents)
	results = []
	for imp in imports:
	for dir in path:
	file = os.path.join(str(dir), imp.replace('.', os.sep) + '.py')
	if os.path.exists(file):
	results.append(env.File(file))
	break
	file = os.path.join(str(dir), imp.replace('.', os.sep), '__init__.py')
	if os.path.exists(file):
	results.append(env.File(file))
	break
	return results

	python_scanner = SCons.Scanner.Scanner(function = python_scan, skeys = ['.py'])


	def code_generate(env, script, target, source, command):
	"""Method to simplify code generation via python scripts.

	http://www.scons.org/wiki/UsingCodeGenerators
	http://www.scons.org/doc/0.98.5/HTML/scons-user/c2768.html
	"""

	# We're generating code using Python scripts, so we have to be
	# careful with our scons elements. This entry represents
	# the generator file in the source directory.
	script_src = env.File(script).srcnode()

	# This command creates generated code in the build directory.
	command = command.replace('$SCRIPT', script_src.path)
	code = env.Command(target, source, command)

	# Explicitly mark that the generated code depends on the generator,
	# and on implicitly imported python modules
	path = (script_src.get_dir(),)
	deps = [script_src]
	deps += script_src.get_implicit_deps(env, python_scanner, path)
	env.Depends(code, deps)

	# Running the Python script causes .pyc files to be generated in the
	# source directory. When we clean up, they should go too. So add side
	# effects for .pyc files
	for dep in deps:
	pyc = env.File(str(dep) + 'c')
	env.SideEffect(pyc, code)

	return code


	def createCodeGenerateMethod(env):
	env.Append(SCANNERS = python_scanner)
	env.AddMethod(code_generate, 'CodeGenerate')


	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_shared_library(env, source, version = ()):
	source = str(source[0])
	version = tuple(map(str, version))
	target_dir = os.path.join(env.Dir('#.').srcnode().abspath, env['build'], 'lib')
	target_name = '.'.join((str(source),) + version)
	last = env.InstallAs(os.path.join(target_dir, target_name), source)
	while len(version):
	version = version[:-1]
	target_name = '.'.join((str(source),) + version)
	action = SCons.Action.Action(symlink, "$TARGET -> $SOURCE")
	last = env.Command(os.path.join(target_dir, target_name), last, action)

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


	_platform_map = {
	'linux2': 'linux',
	'win32': 'windows',
	}


	_machine_map = {
	'x86': 'x86',
	'i386': 'x86',
	'i486': 'x86',
	'i586': 'x86',
	'i686': 'x86',
	'ppc': 'ppc',
	'x86_64': 'x86_64',
	}


	_toolchain_map = {
	'winddk': 'winddk',
	'wince': 'wcesdk',
	}


	_bool_map = {
	'y': 1,
	'yes': 1,
	't': 1,
	'true': 1,
	'1': 1,
	'on': 1,
	'all': 1,
	'n': 0,
	'no': 0,
	'f': 0,
	'false': 0,
	'0': 0,
	'off': 0,
	'none': 0,
	}


	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"""

	from SCons.Script import ARGUMENTS

	# FIXME: this is already too late
	#if env.get('quiet', False):
	# quietCommandLines(env)


	# Platform
	try:
	env['platform'] = ARGUMENTS['platform']
	except KeyError:
	env['platform'] = _platform_map.get(sys.platform, sys.platform)

	# Machine
	try:
	env['machine'] = ARGUMENTS['machine']
	except KeyError:
	env['machine'] = _machine_map.get(os.environ.get('PROCESSOR_ARCHITECTURE', _platform.machine()), 'generic')

	# Toolchain
	try:
	env['toolchain'] = ARGUMENTS['toolchain']
	except KeyError:
	if env['platform'] in ('windows', 'winddk', 'wince') and sys.platform != 'win32':
	env['toolchain'] = 'crossmingw'
	else:
	env['toolchain'] = _toolchain_map.get(env['platform'], 'default')
	if env['toolchain'] == 'crossmingw' and env['machine'] not in ('generic', 'x86'):
	env['machine'] = 'x86'

	try:
	env['MSVS_VERSION'] = ARGUMENTS['MSVS_VERSION']
	except KeyError:
	pass

	# Build type
	env['debug'] = _bool_map[ARGUMENTS.get('debug', 'no')]
	env['profile'] = _bool_map[ARGUMENTS.get('profile', 'no')]

	# Put build output in a separate dir, which depends on the current
	# configuration. See also http://www.scons.org/wiki/AdvancedBuildExample
	try:
	env['build'] = ARGUMENTS['build']
	except KeyError:
	build_topdir = 'build'
	build_subdir = env['platform']
	if env['machine'] != 'generic':
	build_subdir += '-' + env['machine']
	if env['debug']:
	build_subdir += "-debug"
	if env['profile']:
	build_subdir += "-profile"
	env['build'] = 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.SConsignFile(os.path.join(env['build'], '.sconsign'))

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

	# Summary
	print
	print ' platform=%s' % env['platform']
	print ' machine=%s' % env['machine']
	print ' toolchain=%s' % env['toolchain']
	print ' debug=%s' % ['no', 'yes'][env['debug']]
	print ' profile=%s' % ['no', 'yes'][env['profile']]
	print ' build=%s' % env['build']
	print ' %s jobs' % env.GetOption('num_jobs')
	print

	# Load tool chain
	env.Tool(env['toolchain'])

	env['gcc'] = 'gcc' in os.path.basename(env['CC']).split('-')
	env['msvc'] = env['CC'] == 'cl'

	# shortcuts
	debug = env['debug']
	machine = env['machine']
	platform = env['platform']
	x86 = env['machine'] == 'x86'
	ppc = env['machine'] == 'ppc'
	gcc = env['gcc']
	msvc = env['msvc']

	# C preprocessor options
	cppdefines = []
	if debug:
	cppdefines += ['DEBUG']
	else:
	cppdefines += ['NDEBUG']
	if env['profile']:
	cppdefines += ['PROFILE']
	if platform == 'windows':
	cppdefines += [
	'WIN32',
	'_WINDOWS',
	#'_UNICODE',
	#'UNICODE',
	# http://msdn2.microsoft.com/en-us/library/6dwk3a1z.aspx,
	#'WIN32_LEAN_AND_MEAN',
	]
	if msvc:
	cppdefines += [
	'VC_EXTRALEAN',
	'_USE_MATH_DEFINES',
	'_CRT_SECURE_NO_DEPRECATE',
	]
	if debug:
	cppdefines += ['_DEBUG']
	if platform == 'winddk':
	# Mimic WINDDK's builtin flags. See also:
	# - WINDDK's bin/makefile.new i386mk.inc for more info.
	# - buildchk_wxp_x86.log files, generated by the WINDDK's build
	# - http://alter.org.ua/docs/nt_kernel/vc8_proj/
	cppdefines += [
	('_X86_', '1'),
	('i386', '1'),
	'STD_CALL',
	('CONDITION_HANDLING', '1'),
	('NT_INST', '0'),
	('WIN32', '100'),
	('_NT1X_', '100'),
	('WINNT', '1'),
	('_WIN32_WINNT', '0x0501'), # minimum required OS version
	('WINVER', '0x0501'),
	('_WIN32_IE', '0x0603'),
	('WIN32_LEAN_AND_MEAN', '1'),
	('DEVL', '1'),
	('__BUILDMACHINE__', 'WinDDK'),
	('FPO', '0'),
	]
	if debug:
	cppdefines += [('DBG', 1)]
	if platform == 'wince':
	cppdefines += [
	'_CRT_SECURE_NO_DEPRECATE',
	'_USE_32BIT_TIME_T',
	'UNICODE',
	'_UNICODE',
	('UNDER_CE', '600'),
	('_WIN32_WCE', '0x600'),
	'WINCEOEM',
	'WINCEINTERNAL',
	'WIN32',
	'STRICT',
	'x86',
	'_X86_',
	'INTERNATIONAL',
	('INTLMSG_CODEPAGE', '1252'),
	]
	env.Append(CPPDEFINES = cppdefines)

	# C preprocessor includes
	if platform == 'winddk':
	env.Append(CPPPATH = [
	env['SDK_INC_PATH'],
	env['DDK_INC_PATH'],
	env['WDM_INC_PATH'],
	env['CRT_INC_PATH'],
	])

	# C compiler options
	cflags = [] # C
	cxxflags = [] # C++
	ccflags = [] # C & C++
	if gcc:
	if debug:
	ccflags += ['-O0', '-g3']
	elif env['toolchain'] == 'crossmingw':
	ccflags += ['-O0', '-g3'] # mingw 4.2.1 optimizer is broken
	else:
	ccflags += ['-O3', '-g0']
	if env['profile']:
	ccflags += ['-pg']
	if env['machine'] == 'x86':
	ccflags += [
	'-m32',
	#'-march=pentium4',
	'-mmmx', '-msse', '-msse2', # enable SIMD intrinsics
	#'-mfpmath=sse',
	]
	if env['machine'] == 'x86_64':
	ccflags += ['-m64']
	# See also:
	# - http://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html
	ccflags += [
	'-Wall',
	'-Wmissing-field-initializers',
	'-Wpointer-arith',
	'-Wno-long-long',
	'-ffast-math',
	'-fmessage-length=0', # be nice to Eclipse
	]
	cflags += [
	'-Werror=declaration-after-statement',
	'-Wmissing-prototypes',
	'-std=gnu99',
	]
	if msvc:
	# See also:
	# - http://msdn.microsoft.com/en-us/library/19z1t1wy.aspx
	# - cl /?
	if debug:
	ccflags += [
	'/Od', # disable optimizations
	'/Oi', # enable intrinsic functions
	'/Oy-', # disable frame pointer omission
	'/GL-', # disable whole program optimization
	]
	else:
	ccflags += [
	'/Ox', # maximum optimizations
	'/Oi', # enable intrinsic functions
	'/Ot', # favor code speed
	#'/fp:fast', # fast floating point
	]
	if env['profile']:
	ccflags += [
	'/Gh', # enable _penter hook function
	'/GH', # enable _pexit hook function
	]
	ccflags += [
	'/W3', # warning level
	#'/Wp64', # enable 64 bit porting warnings
	]
	if env['machine'] == 'x86':
	ccflags += [
	#'/QIfist', # Suppress _ftol
	#'/arch:SSE2', # use the SSE2 instructions
	]
	if platform == 'windows':
	ccflags += [
	# TODO
	]
	if platform == 'winddk':
	ccflags += [
	'/Zl', # omit default library name in .OBJ
	'/Zp8', # 8bytes struct member alignment
	'/Gy', # separate functions for linker
	'/Gm-', # disable minimal rebuild
	'/WX', # treat warnings as errors
	'/Gz', # __stdcall Calling convention
	'/GX-', # disable C++ EH
	'/GR-', # disable C++ RTTI
	'/GF', # enable read-only string pooling
	'/G6', # optimize for PPro, P-II, P-III
	'/Ze', # enable extensions
	'/Gi-', # disable incremental compilation
	'/QIfdiv-', # disable Pentium FDIV fix
	'/hotpatch', # prepares an image for hotpatching.
	#'/Z7', #enable old-style debug info
	]
	if platform == 'wince':
	# See also C:\WINCE600\public\common\oak\misc\makefile.def
	ccflags += [
	'/Zl', # omit default library name in .OBJ
	'/GF', # enable read-only string pooling
	'/GR-', # disable C++ RTTI
	'/GS', # enable security checks
	# Allow disabling language conformance to maintain backward compat
	#'/Zc:wchar_t-', # don't force wchar_t as native type, instead of typedef
	#'/Zc:forScope-', # don't enforce Standard C++ for scoping rules
	#'/wd4867',
	#'/wd4430',
	#'/MT',
	#'/U_MT',
	]
	# 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['debug']:
	env.Append(CCFLAGS = ['/MTd'])
	env.Append(SHCCFLAGS = ['/LDd'])
	else:
	env.Append(CCFLAGS = ['/MT'])
	env.Append(SHCCFLAGS = ['/LD'])

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

	# Linker options
	linkflags = []
	if gcc:
	if env['machine'] == 'x86':
	linkflags += ['-m32']
	if env['machine'] == 'x86_64':
	linkflags += ['-m64']
	if platform == 'windows' and msvc:
	# See also:
	# - http://msdn2.microsoft.com/en-us/library/y0zzbyt4.aspx
	linkflags += [
	'/fixed:no',
	'/incremental:no',
	]
	if platform == 'winddk':
	linkflags += [
	'/merge:_PAGE=PAGE',
	'/merge:_TEXT=.text',
	'/section:INIT,d',
	'/opt:ref',
	'/opt:icf',
	'/ignore:4198,4010,4037,4039,4065,4070,4078,4087,4089,4221',
	'/incremental:no',
	'/fullbuild',
	'/release',
	'/nodefaultlib',
	'/wx',
	'/debug',
	'/debugtype:cv',
	'/version:5.1',
	'/osversion:5.1',
	'/functionpadmin:5',
	'/safeseh',
	'/pdbcompress',
	'/stack:0x40000,0x1000',
	'/driver',
	'/align:0x80',
	'/subsystem:native,5.01',
	'/base:0x10000',

	'/entry:DrvEnableDriver',
	]
	if env['debug'] or env['profile']:
	linkflags += [
	'/MAP', # http://msdn.microsoft.com/en-us/library/k7xkk3e2.aspx
	]
	if platform == 'wince':
	linkflags += [
	'/nodefaultlib',
	#'/incremental:no',
	#'/fullbuild',
	'/entry:_DllMainCRTStartup',
	]
	env.Append(LINKFLAGS = linkflags)

	# Default libs
	env.Append(LIBS = [])

	# Custom builders and methods
	createConvenienceLibBuilder(env)
	createCodeGenerateMethod(env)
	createInstallMethods(env)

	# for debugging
	#print env.Dump()


	def exists(env):
	return 1