text: #!/usr/bin/env python
  # encoding: utf-8
  # Thomas Nagy, 2005-2018 (ita)
  
  """
  C/C++/D configuration helpers
  """
  
  from __future__ import with_statement
  
  import os, re, shlex
  from waflib import Build, Utils, Task, Options, Logs, Errors, Runner
  from waflib.TaskGen import after_method, feature
  from waflib.Configure import conf
  
  WAF_CONFIG_H   = 'config.h'
  """default name for the config.h file"""
  
  DEFKEYS = 'define_key'
  INCKEYS = 'include_key'
  
  SNIP_EMPTY_PROGRAM = '''
  int main(int argc, char **argv) {
  	(void)argc; (void)argv;
  	return 0;
  }
  '''
  
  MACRO_TO_DESTOS = {
  '__linux__'                                      : 'linux',
  '__GNU__'                                        : 'gnu', # hurd
  '__FreeBSD__'                                    : 'freebsd',
  '__NetBSD__'                                     : 'netbsd',
  '__OpenBSD__'                                    : 'openbsd',
  '__sun'                                          : 'sunos',
  '__hpux'                                         : 'hpux',
  '__sgi'                                          : 'irix',
  '_AIX'                                           : 'aix',
  '__CYGWIN__'                                     : 'cygwin',
  '__MSYS__'                                       : 'cygwin',
  '_UWIN'                                          : 'uwin',
  '_WIN64'                                         : 'win32',
  '_WIN32'                                         : 'win32',
  # Note about darwin: this is also tested with 'defined __APPLE__ && defined __MACH__' somewhere below in this file.
  '__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__'  : 'darwin',
  '__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__' : 'darwin', # iphone
  '__QNX__'                                        : 'qnx',
  '__native_client__'                              : 'nacl' # google native client platform
  }
  
  MACRO_TO_DEST_CPU = {
  '__x86_64__'  : 'x86_64',
  '__amd64__'   : 'x86_64',
  '__i386__'    : 'x86',
  '__ia64__'    : 'ia',
  '__mips__'    : 'mips',
  '__sparc__'   : 'sparc',
  '__alpha__'   : 'alpha',
  '__aarch64__' : 'aarch64',
  '__thumb__'   : 'thumb',
  '__arm__'     : 'arm',
  '__hppa__'    : 'hppa',
  '__powerpc__' : 'powerpc',
  '__ppc__'     : 'powerpc',
  '__convex__'  : 'convex',
  '__m68k__'    : 'm68k',
  '__s390x__'   : 's390x',
  '__s390__'    : 's390',
  '__sh__'      : 'sh',
  '__xtensa__'  : 'xtensa',
  }
  
  @conf
  def parse_flags(self, line, uselib_store, env=None, force_static=False, posix=None):
  	"""
  	Parses flags from the input lines, and adds them to the relevant use variables::
  
  		def configure(conf):
  			conf.parse_flags('-O3', 'FOO')
  			# conf.env.CXXFLAGS_FOO = ['-O3']
  			# conf.env.CFLAGS_FOO = ['-O3']
  
  	:param line: flags
  	:type line: string
  	:param uselib_store: where to add the flags
  	:type uselib_store: string
  	:param env: config set or conf.env by default
  	:type env: :py:class:`waflib.ConfigSet.ConfigSet`
  	"""
  
  	assert(isinstance(line, str))
  
  	env = env or self.env
  
  	# Issue 811 and 1371
  	if posix is None:
  		posix = True
  		if '\\' in line:
  			posix = ('\\ ' in line) or ('\\\\' in line)
  
  	lex = shlex.shlex(line, posix=posix)
  	lex.whitespace_split = True
  	lex.commenters = ''
  	lst = list(lex)
  
  	# append_unique is not always possible
  	# for example, apple flags may require both -arch i386 and -arch ppc
  	uselib = uselib_store
  	def app(var, val):
  		env.append_value('%s_%s' % (var, uselib), val)
  	def appu(var, val):
  		env.append_unique('%s_%s' % (var, uselib), val)
  	static = False
  	while lst:
  		x = lst.pop(0)
  		st = x[:2]
  		ot = x[2:]
  
  		if st == '-I' or st == '/I':
  			if not ot:
  				ot = lst.pop(0)
  			appu('INCLUDES', ot)
  		elif st == '-i':
  			tmp = [x, lst.pop(0)]
  			app('CFLAGS', tmp)
  			app('CXXFLAGS', tmp)
  		elif st == '-D' or (env.CXX_NAME == 'msvc' and st == '/D'): # not perfect but..
  			if not ot:
  				ot = lst.pop(0)
  			app('DEFINES', ot)
  		elif st == '-l':
  			if not ot:
  				ot = lst.pop(0)
  			prefix = 'STLIB' if (force_static or static) else 'LIB'
  			app(prefix, ot)
  		elif st == '-L':
  			if not ot:
  				ot = lst.pop(0)
  			prefix = 'STLIBPATH' if (force_static or static) else 'LIBPATH'
  			appu(prefix, ot)
  		elif x.startswith('/LIBPATH:'):
  			prefix = 'STLIBPATH' if (force_static or static) else 'LIBPATH'
  			appu(prefix, x.replace('/LIBPATH:', ''))
  		elif x.startswith('-std='):
  			prefix = 'CXXFLAGS' if '++' in x else 'CFLAGS'
  			app(prefix, x)
  		elif x.startswith('+') or x in ('-pthread', '-fPIC', '-fpic', '-fPIE', '-fpie'):
  			app('CFLAGS', x)
  			app('CXXFLAGS', x)
  			app('LINKFLAGS', x)
  		elif x == '-framework':
  			appu('FRAMEWORK', lst.pop(0))
  		elif x.startswith('-F'):
  			appu('FRAMEWORKPATH', x[2:])
  		elif x == '-Wl,-rpath' or x == '-Wl,-R':
  			app('RPATH', lst.pop(0).lstrip('-Wl,'))
  		elif x.startswith('-Wl,-R,'):
  			app('RPATH', x[7:])
  		elif x.startswith('-Wl,-R'):
  			app('RPATH', x[6:])
  		elif x.startswith('-Wl,-rpath,'):
  			app('RPATH', x[11:])
  		elif x == '-Wl,-Bstatic' or x == '-Bstatic':
  			static = True
  		elif x == '-Wl,-Bdynamic' or x == '-Bdynamic':
  			static = False
  		elif x.startswith('-Wl') or x in ('-rdynamic', '-pie'):
  			app('LINKFLAGS', x)
  		elif x.startswith(('-m', '-f', '-dynamic', '-O', '-g')):
  			# Adding the -W option breaks python builds on Openindiana
  			app('CFLAGS', x)
  			app('CXXFLAGS', x)
  		elif x.startswith('-bundle'):
  			app('LINKFLAGS', x)
  		elif x.startswith(('-undefined', '-Xlinker')):
  			arg = lst.pop(0)
  			app('LINKFLAGS', [x, arg])
  		elif x.startswith(('-arch', '-isysroot')):
  			tmp = [x, lst.pop(0)]
  			app('CFLAGS', tmp)
  			app('CXXFLAGS', tmp)
  			app('LINKFLAGS', tmp)
  		elif x.endswith(('.a', '.so', '.dylib', '.lib')):
  			appu('LINKFLAGS', x) # not cool, #762
  		else:
  			self.to_log('Unhandled flag %r' % x)
  
  @conf
  def validate_cfg(self, kw):
  	"""
  	Searches for the program *pkg-config* if missing, and validates the
  	parameters to pass to :py:func:`waflib.Tools.c_config.exec_cfg`.
  
  	:param path: the **-config program to use** (default is *pkg-config*)
  	:type path: list of string
  	:param msg: message to display to describe the test executed
  	:type msg: string
  	:param okmsg: message to display when the test is successful
  	:type okmsg: string
  	:param errmsg: message to display in case of error
  	:type errmsg: string
  	"""
  	if not 'path' in kw:
  		if not self.env.PKGCONFIG:
  			self.find_program('pkg-config', var='PKGCONFIG')
  		kw['path'] = self.env.PKGCONFIG
  
  	# verify that exactly one action is requested
  	s = ('atleast_pkgconfig_version' in kw) + ('modversion' in kw) + ('package' in kw)
  	if s != 1:
  		raise ValueError('exactly one of atleast_pkgconfig_version, modversion and package must be set')
  	if not 'msg' in kw:
  		if 'atleast_pkgconfig_version' in kw:
  			kw['msg'] = 'Checking for pkg-config version >= %r' % kw['atleast_pkgconfig_version']
  		elif 'modversion' in kw:
  			kw['msg'] = 'Checking for %r version' % kw['modversion']
  		else:
  			kw['msg'] = 'Checking for %r' %(kw['package'])
  
  	# let the modversion check set the okmsg to the detected version
  	if not 'okmsg' in kw and not 'modversion' in kw:
  		kw['okmsg'] = 'yes'
  	if not 'errmsg' in kw:
  		kw['errmsg'] = 'not found'
  
  	# pkg-config version
  	if 'atleast_pkgconfig_version' in kw:
  		pass
  	elif 'modversion' in kw:
  		if not 'uselib_store' in kw:
  			kw['uselib_store'] = kw['modversion']
  		if not 'define_name' in kw:
  			kw['define_name'] = '%s_VERSION' % Utils.quote_define_name(kw['uselib_store'])
  	else:
  		if not 'uselib_store' in kw:
  			kw['uselib_store'] = Utils.to_list(kw['package'])[0].upper()
  		if not 'define_name' in kw:
  			kw['define_name'] = self.have_define(kw['uselib_store'])
  
  @conf
  def exec_cfg(self, kw):
  	"""
  	Executes ``pkg-config`` or other ``-config`` applications to collect configuration flags:
  
  	* if atleast_pkgconfig_version is given, check that pkg-config has the version n and return
  	* if modversion is given, then return the module version
  	* else, execute the *-config* program with the *args* and *variables* given, and set the flags on the *conf.env.FLAGS_name* variable
  
  	:param atleast_pkgconfig_version: minimum pkg-config version to use (disable other tests)
  	:type atleast_pkgconfig_version: string
  	:param package: package name, for example *gtk+-2.0*
  	:type package: string
  	:param uselib_store: if the test is successful, define HAVE\_*name*. It is also used to define *conf.env.FLAGS_name* variables.
  	:type uselib_store: string
  	:param modversion: if provided, return the version of the given module and define *name*\_VERSION
  	:type modversion: string
  	:param args: arguments to give to *package* when retrieving flags
  	:type args: list of string
  	:param variables: return the values of particular variables
  	:type variables: list of string
  	:param define_variable: additional variables to define (also in conf.env.PKG_CONFIG_DEFINES)
  	:type define_variable: dict(string: string)
  	"""
  
  	path = Utils.to_list(kw['path'])
  	env = self.env.env or None
  	if kw.get('pkg_config_path'):
  		if not env:
  			env = dict(self.environ)
  		env['PKG_CONFIG_PATH'] = kw['pkg_config_path']
  
  	def define_it():
  		define_name = kw['define_name']
  		# by default, add HAVE_X to the config.h, else provide DEFINES_X for use=X
  		if kw.get('global_define', 1):
  			self.define(define_name, 1, False)
  		else:
  			self.env.append_unique('DEFINES_%s' % kw['uselib_store'], "%s=1" % define_name)
  
  		if kw.get('add_have_to_env', 1):
  			self.env[define_name] = 1
  
  	# pkg-config version
  	if 'atleast_pkgconfig_version' in kw:
  		cmd = path + ['--atleast-pkgconfig-version=%s' % kw['atleast_pkgconfig_version']]
  		self.cmd_and_log(cmd, env=env)
  		return
  
  	# single version for a module
  	if 'modversion' in kw:
  		version = self.cmd_and_log(path + ['--modversion', kw['modversion']], env=env).strip()
  		if not 'okmsg' in kw:
  			kw['okmsg'] = version
  		self.define(kw['define_name'], version)
  		return version
  
  	lst = [] + path
  
  	defi = kw.get('define_variable')
  	if not defi:
  		defi = self.env.PKG_CONFIG_DEFINES or {}
  	for key, val in defi.items():
  		lst.append('--define-variable=%s=%s' % (key, val))
  
  	static = kw.get('force_static', False)
  	if 'args' in kw:
  		args = Utils.to_list(kw['args'])
  		if '--static' in args or '--static-libs' in args:
  			static = True
  		lst += args
  
  	# tools like pkgconf expect the package argument after the -- ones -_-
  	lst.extend(Utils.to_list(kw['package']))
  
  	# retrieving variables of a module
  	if 'variables' in kw:
  		v_env = kw.get('env', self.env)
  		vars = Utils.to_list(kw['variables'])
  		for v in vars:
  			val = self.cmd_and_log(lst + ['--variable=' + v], env=env).strip()
  			var = '%s_%s' % (kw['uselib_store'], v)
  			v_env[var] = val
  		return
  
  	# so we assume the command-line will output flags to be parsed afterwards
  	ret = self.cmd_and_log(lst, env=env)
  
  	define_it()
  	self.parse_flags(ret, kw['uselib_store'], kw.get('env', self.env), force_static=static, posix=kw.get('posix'))
  	return ret
  
  @conf
  def check_cfg(self, *k, **kw):
  	"""
  	Checks for configuration flags using a **-config**-like program (pkg-config, sdl-config, etc).
  	This wraps internal calls to :py:func:`waflib.Tools.c_config.validate_cfg` and :py:func:`waflib.Tools.c_config.exec_cfg`
  
  	A few examples::
  
  		def configure(conf):
  			conf.load('compiler_c')
  			conf.check_cfg(package='glib-2.0', args='--libs --cflags')
  			conf.check_cfg(package='pango')
  			conf.check_cfg(package='pango', uselib_store='MYPANGO', args=['--cflags', '--libs'])
  			conf.check_cfg(package='pango',
  				args=['pango >= 0.1.0', 'pango < 9.9.9', '--cflags', '--libs'],
  				msg="Checking for 'pango 0.1.0'")
  			conf.check_cfg(path='sdl-config', args='--cflags --libs', package='', uselib_store='SDL')
  			conf.check_cfg(path='mpicc', args='--showme:compile --showme:link',
  				package='', uselib_store='OPEN_MPI', mandatory=False)
  			# variables
  			conf.check_cfg(package='gtk+-2.0', variables=['includedir', 'prefix'], uselib_store='FOO')
  			print(conf.env.FOO_includedir)
  	"""
  	self.validate_cfg(kw)
  	if 'msg' in kw:
  		self.start_msg(kw['msg'], **kw)
  	ret = None
  	try:
  		ret = self.exec_cfg(kw)
  	except self.errors.WafError as e:
  		if 'errmsg' in kw:
  			self.end_msg(kw['errmsg'], 'YELLOW', **kw)
  		if Logs.verbose > 1:
  			self.to_log('Command failure: %s' % e)
  		self.fatal('The configuration failed')
  	else:
  		if not ret:
  			ret = True
  		kw['success'] = ret
  		if 'okmsg' in kw:
  			self.end_msg(self.ret_msg(kw['okmsg'], kw), **kw)
  
  	return ret
  
  def build_fun(bld):
  	"""
  	Build function that is used for running configuration tests with ``conf.check()``
  	"""
  	if bld.kw['compile_filename']:
  		node = bld.srcnode.make_node(bld.kw['compile_filename'])
  		node.write(bld.kw['code'])
  
  	o = bld(features=bld.kw['features'], source=bld.kw['compile_filename'], target='testprog')
  
  	for k, v in bld.kw.items():
  		setattr(o, k, v)
  
  	if not bld.kw.get('quiet'):
  		bld.conf.to_log("==>\n%s\n<==" % bld.kw['code'])
  
  @conf
  def validate_c(self, kw):
  	"""
  	Pre-checks the parameters that will be given to :py:func:`waflib.Configure.run_build`
  
  	:param compiler: c or cxx (tries to guess what is best)
  	:type compiler: string
  	:param type: cprogram, cshlib, cstlib - not required if *features are given directly*
  	:type type: binary to create
  	:param feature: desired features for the task generator that will execute the test, for example ``cxx cxxstlib``
  	:type feature: list of string
  	:param fragment: provide a piece of code for the test (default is to let the system create one)
  	:type fragment: string
  	:param uselib_store: define variables after the test is executed (IMPORTANT!)
  	:type uselib_store: string
  	:param use: parameters to use for building (just like the normal *use* keyword)
  	:type use: list of string
  	:param define_name: define to set when the check is over
  	:type define_name: string
  	:param execute: execute the resulting binary
  	:type execute: bool
  	:param define_ret: if execute is set to True, use the execution output in both the define and the return value
  	:type define_ret: bool
  	:param header_name: check for a particular header
  	:type header_name: string
  	:param auto_add_header_name: if header_name was set, add the headers in env.INCKEYS so the next tests will include these headers
  	:type auto_add_header_name: bool
  	"""
  	for x in ('type_name', 'field_name', 'function_name'):
  		if x in kw:
  			Logs.warn('Invalid argument %r in test' % x)
  
  	if not 'build_fun' in kw:
  		kw['build_fun'] = build_fun
  
  	if not 'env' in kw:
  		kw['env'] = self.env.derive()
  	env = kw['env']
  
  	if not 'compiler' in kw and not 'features' in kw:
  		kw['compiler'] = 'c'
  		if env.CXX_NAME and Task.classes.get('cxx'):
  			kw['compiler'] = 'cxx'
  			if not self.env.CXX:
  				self.fatal('a c++ compiler is required')
  		else:
  			if not self.env.CC:
  				self.fatal('a c compiler is required')
  
  	if not 'compile_mode' in kw:
  		kw['compile_mode'] = 'c'
  		if 'cxx' in Utils.to_list(kw.get('features', [])) or kw.get('compiler') == 'cxx':
  			kw['compile_mode'] = 'cxx'
  
  	if not 'type' in kw:
  		kw['type'] = 'cprogram'
  
  	if not 'features' in kw:
  		if not 'header_name' in kw or kw.get('link_header_test', True):
  			kw['features'] = [kw['compile_mode'], kw['type']] # "c ccprogram"
  		else:
  			kw['features'] = [kw['compile_mode']]
  	else:
  		kw['features'] = Utils.to_list(kw['features'])
  
  	if not 'compile_filename' in kw:
  		kw['compile_filename'] = 'test.c' + ((kw['compile_mode'] == 'cxx') and 'pp' or '')
  
  	def to_header(dct):
  		if 'header_name' in dct:
  			dct = Utils.to_list(dct['header_name'])
  			return ''.join(['#include <%s>\n' % x for x in dct])
  		return ''
  
  	if 'framework_name' in kw:
  		# OSX, not sure this is used anywhere
  		fwkname = kw['framework_name']
  		if not 'uselib_store' in kw:
  			kw['uselib_store'] = fwkname.upper()
  		if not kw.get('no_header'):
  			fwk = '%s/%s.h' % (fwkname, fwkname)
  			if kw.get('remove_dot_h'):
  				fwk = fwk[:-2]
  			val = kw.get('header_name', [])
  			kw['header_name'] = Utils.to_list(val) + [fwk]
  		kw['msg'] = 'Checking for framework %s' % fwkname
  		kw['framework'] = fwkname
  
  	elif 'header_name' in kw:
  		if not 'msg' in kw:
  			kw['msg'] = 'Checking for header %s' % kw['header_name']
  
  		l = Utils.to_list(kw['header_name'])
  		assert len(l), 'list of headers in header_name is empty'
  
  		kw['code'] = to_header(kw) + SNIP_EMPTY_PROGRAM
  		if not 'uselib_store' in kw:
  			kw['uselib_store'] = l[0].upper()
  		if not 'define_name' in kw:
  			kw['define_name'] = self.have_define(l[0])
  
  	if 'lib' in kw:
  		if not 'msg' in kw:
  			kw['msg'] = 'Checking for library %s' % kw['lib']
  		if not 'uselib_store' in kw:
  			kw['uselib_store'] = kw['lib'].upper()
  
  	if 'stlib' in kw:
  		if not 'msg' in kw:
  			kw['msg'] = 'Checking for static library %s' % kw['stlib']
  		if not 'uselib_store' in kw:
  			kw['uselib_store'] = kw['stlib'].upper()
  
  	if 'fragment' in kw:
  		# an additional code fragment may be provided to replace the predefined code
  		# in custom headers
  		kw['code'] = kw['fragment']
  		if not 'msg' in kw:
  			kw['msg'] = 'Checking for code snippet'
  		if not 'errmsg' in kw:
  			kw['errmsg'] = 'no'
  
  	for (flagsname,flagstype) in (('cxxflags','compiler'), ('cflags','compiler'), ('linkflags','linker')):
  		if flagsname in kw:
  			if not 'msg' in kw:
  				kw['msg'] = 'Checking for %s flags %s' % (flagstype, kw[flagsname])
  			if not 'errmsg' in kw:
  				kw['errmsg'] = 'no'
  
  	if not 'execute' in kw:
  		kw['execute'] = False
  	if kw['execute']:
  		kw['features'].append('test_exec')
  		kw['chmod'] = Utils.O755
  
  	if not 'errmsg' in kw:
  		kw['errmsg'] = 'not found'
  
  	if not 'okmsg' in kw:
  		kw['okmsg'] = 'yes'
  
  	if not 'code' in kw:
  		kw['code'] = SNIP_EMPTY_PROGRAM
  
  	# if there are headers to append automatically to the next tests
  	if self.env[INCKEYS]:
  		kw['code'] = '\n'.join(['#include <%s>' % x for x in self.env[INCKEYS]]) + '\n' + kw['code']
  
  	# in case defines lead to very long command-lines
  	if kw.get('merge_config_header') or env.merge_config_header:
  		kw['code'] = '%s\n\n%s' % (self.get_config_header(), kw['code'])
  		env.DEFINES = [] # modify the copy
  
  	if not kw.get('success'):
  		kw['success'] = None
  
  	if 'define_name' in kw:
  		self.undefine(kw['define_name'])
  	if not 'msg' in kw:
  		self.fatal('missing "msg" in conf.check(...)')
  
  @conf
  def post_check(self, *k, **kw):
  	"""
  	Sets the variables after a test executed in
  	:py:func:`waflib.Tools.c_config.check` was run successfully
  	"""
  	is_success = 0
  	if kw['execute']:
  		if kw['success'] is not None:
  			if kw.get('define_ret'):
  				is_success = kw['success']
  			else:
  				is_success = (kw['success'] == 0)
  	else:
  		is_success = (kw['success'] == 0)
  
  	if kw.get('define_name'):
  		comment = kw.get('comment', '')
  		define_name = kw['define_name']
  		if kw['execute'] and kw.get('define_ret') and isinstance(is_success, str):
  			if kw.get('global_define', 1):
  				self.define(define_name, is_success, quote=kw.get('quote', 1), comment=comment)
  			else:
  				if kw.get('quote', 1):
  					succ = '"%s"' % is_success
  				else:
  					succ = int(is_success)
  				val = '%s=%s' % (define_name, succ)
  				var = 'DEFINES_%s' % kw['uselib_store']
  				self.env.append_value(var, val)
  		else:
  			if kw.get('global_define', 1):
  				self.define_cond(define_name, is_success, comment=comment)
  			else:
  				var = 'DEFINES_%s' % kw['uselib_store']
  				self.env.append_value(var, '%s=%s' % (define_name, int(is_success)))
  
  		# define conf.env.HAVE_X to 1
  		if kw.get('add_have_to_env', 1):
  			if kw.get('uselib_store'):
  				self.env[self.have_define(kw['uselib_store'])] = 1
  			elif kw['execute'] and kw.get('define_ret'):
  				self.env[define_name] = is_success
  			else:
  				self.env[define_name] = int(is_success)
  
  	if 'header_name' in kw:
  		if kw.get('auto_add_header_name'):
  			self.env.append_value(INCKEYS, Utils.to_list(kw['header_name']))
  
  	if is_success and 'uselib_store' in kw:
  		from waflib.Tools import ccroot
  		# See get_uselib_vars in ccroot.py
  		_vars = set()
  		for x in kw['features']:
  			if x in ccroot.USELIB_VARS:
  				_vars |= ccroot.USELIB_VARS[x]
  
  		for k in _vars:
  			x = k.lower()
  			if x in kw:
  				self.env.append_value(k + '_' + kw['uselib_store'], kw[x])
  	return is_success
  
  @conf
  def check(self, *k, **kw):
  	"""
  	Performs a configuration test by calling :py:func:`waflib.Configure.run_build`.
  	For the complete list of parameters, see :py:func:`waflib.Tools.c_config.validate_c`.
  	To force a specific compiler, pass ``compiler='c'`` or ``compiler='cxx'`` to the list of arguments
  
  	Besides build targets, complete builds can be given through a build function. All files will
  	be written to a temporary directory::
  
  		def build(bld):
  			lib_node = bld.srcnode.make_node('libdir/liblc1.c')
  			lib_node.parent.mkdir()
  			lib_node.write('#include <stdio.h>\\nint lib_func(void) { FILE *f = fopen("foo", "r");}\\n', 'w')
  			bld(features='c cshlib', source=[lib_node], linkflags=conf.env.EXTRA_LDFLAGS, target='liblc')
  		conf.check(build_fun=build, msg=msg)
  	"""
  	self.validate_c(kw)
  	self.start_msg(kw['msg'], **kw)
  	ret = None
  	try:
  		ret = self.run_build(*k, **kw)
  	except self.errors.ConfigurationError:
  		self.end_msg(kw['errmsg'], 'YELLOW', **kw)
  		if Logs.verbose > 1:
  			raise
  		else:
  			self.fatal('The configuration failed')
  	else:
  		kw['success'] = ret
  
  	ret = self.post_check(*k, **kw)
  	if not ret:
  		self.end_msg(kw['errmsg'], 'YELLOW', **kw)
  		self.fatal('The configuration failed %r' % ret)
  	else:
  		self.end_msg(self.ret_msg(kw['okmsg'], kw), **kw)
  	return ret
  
  class test_exec(Task.Task):
  	"""
  	A task that runs programs after they are built. See :py:func:`waflib.Tools.c_config.test_exec_fun`.
  	"""
  	color = 'PINK'
  	def run(self):
  		if getattr(self.generator, 'rpath', None):
  			if getattr(self.generator, 'define_ret', False):
  				self.generator.bld.retval = self.generator.bld.cmd_and_log([self.inputs[0].abspath()])
  			else:
  				self.generator.bld.retval = self.generator.bld.exec_command([self.inputs[0].abspath()])
  		else:
  			env = self.env.env or {}
  			env.update(dict(os.environ))
  			for var in ('LD_LIBRARY_PATH', 'DYLD_LIBRARY_PATH', 'PATH'):
  				env[var] = self.inputs[0].parent.abspath() + os.path.pathsep + env.get(var, '')
  			if getattr(self.generator, 'define_ret', False):
  				self.generator.bld.retval = self.generator.bld.cmd_and_log([self.inputs[0].abspath()], env=env)
  			else:
  				self.generator.bld.retval = self.generator.bld.exec_command([self.inputs[0].abspath()], env=env)
  
  @feature('test_exec')
  @after_method('apply_link')
  def test_exec_fun(self):
  	"""
  	The feature **test_exec** is used to create a task that will to execute the binary
  	created (link task output) during the build. The exit status will be set
  	on the build context, so only one program may have the feature *test_exec*.
  	This is used by configuration tests::
  
  		def configure(conf):
  			conf.check(execute=True)
  	"""
  	self.create_task('test_exec', self.link_task.outputs[0])
  
  @conf
  def check_cxx(self, *k, **kw):
  	"""
  	Runs a test with a task generator of the form::
  
  		conf.check(features='cxx cxxprogram', ...)
  	"""
  	kw['compiler'] = 'cxx'
  	return self.check(*k, **kw)
  
  @conf
  def check_cc(self, *k, **kw):
  	"""
  	Runs a test with a task generator of the form::
  
  		conf.check(features='c cprogram', ...)
  	"""
  	kw['compiler'] = 'c'
  	return self.check(*k, **kw)
  
  @conf
  def set_define_comment(self, key, comment):
  	"""
  	Sets a comment that will appear in the configuration header
  
  	:type key: string
  	:type comment: string
  	"""
  	coms = self.env.DEFINE_COMMENTS
  	if not coms:
  		coms = self.env.DEFINE_COMMENTS = {}
  	coms[key] = comment or ''
  
  @conf
  def get_define_comment(self, key):
  	"""
  	Returns the comment associated to a define
  
  	:type key: string
  	"""
  	coms = self.env.DEFINE_COMMENTS or {}
  	return coms.get(key, '')
  
  @conf
  def define(self, key, val, quote=True, comment=''):
  	"""
  	Stores a single define and its state into ``conf.env.DEFINES``. The value is cast to an integer (0/1).
  
  	:param key: define name
  	:type key: string
  	:param val: value
  	:type val: int or string
  	:param quote: enclose strings in quotes (yes by default)
  	:type quote: bool
  	"""
  	assert isinstance(key, str)
  	if not key:
  		return
  	if val is True:
  		val = 1
  	elif val in (False, None):
  		val = 0
  
  	if isinstance(val, int) or isinstance(val, float):
  		s = '%s=%s'
  	else:
  		s = quote and '%s="%s"' or '%s=%s'
  	app = s % (key, str(val))
  
  	ban = key + '='
  	lst = self.env.DEFINES
  	for x in lst:
  		if x.startswith(ban):
  			lst[lst.index(x)] = app
  			break
  	else:
  		self.env.append_value('DEFINES', app)
  
  	self.env.append_unique(DEFKEYS, key)
  	self.set_define_comment(key, comment)
  
  @conf
  def undefine(self, key, comment=''):
  	"""
  	Removes a global define from ``conf.env.DEFINES``
  
  	:param key: define name
  	:type key: string
  	"""
  	assert isinstance(key, str)
  	if not key:
  		return
  	ban = key + '='
  	lst = [x for x in self.env.DEFINES if not x.startswith(ban)]
  	self.env.DEFINES = lst
  	self.env.append_unique(DEFKEYS, key)
  	self.set_define_comment(key, comment)
  
  @conf
  def define_cond(self, key, val, comment=''):
  	"""
  	Conditionally defines a name::
  
  		def configure(conf):
  			conf.define_cond('A', True)
  			# equivalent to:
  			# if val: conf.define('A', 1)
  			# else: conf.undefine('A')
  
  	:param key: define name
  	:type key: string
  	:param val: value
  	:type val: int or string
  	"""
  	assert isinstance(key, str)
  	if not key:
  		return
  	if val:
  		self.define(key, 1, comment=comment)
  	else:
  		self.undefine(key, comment=comment)
  
  @conf
  def is_defined(self, key):
  	"""
  	Indicates whether a particular define is globally set in ``conf.env.DEFINES``.
  
  	:param key: define name
  	:type key: string
  	:return: True if the define is set
  	:rtype: bool
  	"""
  	assert key and isinstance(key, str)
  
  	ban = key + '='
  	for x in self.env.DEFINES:
  		if x.startswith(ban):
  			return True
  	return False
  
  @conf
  def get_define(self, key):
  	"""
  	Returns the value of an existing define, or None if not found
  
  	:param key: define name
  	:type key: string
  	:rtype: string
  	"""
  	assert key and isinstance(key, str)
  
  	ban = key + '='
  	for x in self.env.DEFINES:
  		if x.startswith(ban):
  			return x[len(ban):]
  	return None
  
  @conf
  def have_define(self, key):
  	"""
  	Returns a variable suitable for command-line or header use by removing invalid characters
  	and prefixing it with ``HAVE_``
  
  	:param key: define name
  	:type key: string
  	:return: the input key prefixed by *HAVE_* and substitute any invalid characters.
  	:rtype: string
  	"""
  	return (self.env.HAVE_PAT or 'HAVE_%s') % Utils.quote_define_name(key)
  
  @conf
  def write_config_header(self, configfile='', guard='', top=False, defines=True, headers=False, remove=True, define_prefix=''):
  	"""
  	Writes a configuration header containing defines and includes::
  
  		def configure(cnf):
  			cnf.define('A', 1)
  			cnf.write_config_header('config.h')
  
  	This function only adds include guards (if necessary), consult
  	:py:func:`waflib.Tools.c_config.get_config_header` for details on the body.
  
  	:param configfile: path to the file to create (relative or absolute)
  	:type configfile: string
  	:param guard: include guard name to add, by default it is computed from the file name
  	:type guard: string
  	:param top: write the configuration header from the build directory (default is from the current path)
  	:type top: bool
  	:param defines: add the defines (yes by default)
  	:type defines: bool
  	:param headers: add #include in the file
  	:type headers: bool
  	:param remove: remove the defines after they are added (yes by default, works like in autoconf)
  	:type remove: bool
  	:type define_prefix: string
  	:param define_prefix: prefix all the defines in the file with a particular prefix
  	"""
  	if not configfile:
  		configfile = WAF_CONFIG_H
  	waf_guard = guard or 'W_%s_WAF' % Utils.quote_define_name(configfile)
  
  	node = top and self.bldnode or self.path.get_bld()
  	node = node.make_node(configfile)
  	node.parent.mkdir()
  
  	lst = ['/* WARNING! All changes made to this file will be lost! */\n']
  	lst.append('#ifndef %s\n#define %s\n' % (waf_guard, waf_guard))
  	lst.append(self.get_config_header(defines, headers, define_prefix=define_prefix))
  	lst.append('\n#endif /* %s */\n' % waf_guard)
  
  	node.write('\n'.join(lst))
  
  	# config files must not be removed on "waf clean"
  	self.env.append_unique(Build.CFG_FILES, [node.abspath()])
  
  	if remove:
  		for key in self.env[DEFKEYS]:
  			self.undefine(key)
  		self.env[DEFKEYS] = []
  
  @conf
  def get_config_header(self, defines=True, headers=False, define_prefix=''):
  	"""
  	Creates the contents of a ``config.h`` file from the defines and includes
  	set in conf.env.define_key / conf.env.include_key. No include guards are added.
  
  	A prelude will be added from the variable env.WAF_CONFIG_H_PRELUDE if provided. This
  	can be used to insert complex macros or include guards::
  
  		def configure(conf):
  			conf.env.WAF_CONFIG_H_PRELUDE = '#include <unistd.h>\\n'
  			conf.write_config_header('config.h')
  
  	:param defines: write the defines values
  	:type defines: bool
  	:param headers: write include entries for each element in self.env.INCKEYS
  	:type headers: bool
  	:type define_prefix: string
  	:param define_prefix: prefix all the defines with a particular prefix
  	:return: the contents of a ``config.h`` file
  	:rtype: string
  	"""
  	lst = []
  
  	if self.env.WAF_CONFIG_H_PRELUDE:
  		lst.append(self.env.WAF_CONFIG_H_PRELUDE)
  
  	if headers:
  		for x in self.env[INCKEYS]:
  			lst.append('#include <%s>' % x)
  
  	if defines:
  		tbl = {}
  		for k in self.env.DEFINES:
  			a, _, b = k.partition('=')
  			tbl[a] = b
  
  		for k in self.env[DEFKEYS]:
  			caption = self.get_define_comment(k)
  			if caption:
  				caption = ' /* %s */' % caption
  			try:
  				txt = '#define %s%s %s%s' % (define_prefix, k, tbl[k], caption)
  			except KeyError:
  				txt = '/* #undef %s%s */%s' % (define_prefix, k, caption)
  			lst.append(txt)
  	return "\n".join(lst)
  
  @conf
  def cc_add_flags(conf):
  	"""
  	Adds CFLAGS / CPPFLAGS from os.environ to conf.env
  	"""
  	conf.add_os_flags('CPPFLAGS', dup=False)
  	conf.add_os_flags('CFLAGS', dup=False)
  
  @conf
  def cxx_add_flags(conf):
  	"""
  	Adds CXXFLAGS / CPPFLAGS from os.environ to conf.env
  	"""
  	conf.add_os_flags('CPPFLAGS', dup=False)
  	conf.add_os_flags('CXXFLAGS', dup=False)
  
  @conf
  def link_add_flags(conf):
  	"""
  	Adds LINKFLAGS / LDFLAGS from os.environ to conf.env
  	"""
  	conf.add_os_flags('LINKFLAGS', dup=False)
  	conf.add_os_flags('LDFLAGS', dup=False)
  
  @conf
  def cc_load_tools(conf):
  	"""
  	Loads the Waf c extensions
  	"""
  	if not conf.env.DEST_OS:
  		conf.env.DEST_OS = Utils.unversioned_sys_platform()
  	conf.load('c')
  
  @conf
  def cxx_load_tools(conf):
  	"""
  	Loads the Waf c++ extensions
  	"""
  	if not conf.env.DEST_OS:
  		conf.env.DEST_OS = Utils.unversioned_sys_platform()
  	conf.load('cxx')
  
  @conf
  def get_cc_version(conf, cc, gcc=False, icc=False, clang=False):
  	"""
  	Runs the preprocessor to determine the gcc/icc/clang version
  
  	The variables CC_VERSION, DEST_OS, DEST_BINFMT and DEST_CPU will be set in *conf.env*
  
  	:raise: :py:class:`waflib.Errors.ConfigurationError`
  	"""
  	cmd = cc + ['-dM', '-E', '-']
  	env = conf.env.env or None
  	try:
  		out, err = conf.cmd_and_log(cmd, output=0, input='\n'.encode(), env=env)
  	except Errors.WafError:
  		conf.fatal('Could not determine the compiler version %r' % cmd)
  
  	if gcc:
  		if out.find('__INTEL_COMPILER') >= 0:
  			conf.fatal('The intel compiler pretends to be gcc')
  		if out.find('__GNUC__') < 0 and out.find('__clang__') < 0:
  			conf.fatal('Could not determine the compiler type')
  
  	if icc and out.find('__INTEL_COMPILER') < 0:
  		conf.fatal('Not icc/icpc')
  
  	if clang and out.find('__clang__') < 0:
  		conf.fatal('Not clang/clang++')
  	if not clang and out.find('__clang__') >= 0:
  		conf.fatal('Could not find gcc/g++ (only Clang), if renamed try eg: CC=gcc48 CXX=g++48 waf configure')
  
  	k = {}
  	if icc or gcc or clang:
  		out = out.splitlines()
  		for line in out:
  			lst = shlex.split(line)
  			if len(lst)>2:
  				key = lst[1]
  				val = lst[2]
  				k[key] = val
  
  		def isD(var):
  			return var in k
  
  		# Some documentation is available at http://predef.sourceforge.net
  		# The names given to DEST_OS must match what Utils.unversioned_sys_platform() returns.
  		if not conf.env.DEST_OS:
  			conf.env.DEST_OS = ''
  		for i in MACRO_TO_DESTOS:
  			if isD(i):
  				conf.env.DEST_OS = MACRO_TO_DESTOS[i]
  				break
  		else:
  			if isD('__APPLE__') and isD('__MACH__'):
  				conf.env.DEST_OS = 'darwin'
  			elif isD('__unix__'): # unix must be tested last as it's a generic fallback
  				conf.env.DEST_OS = 'generic'
  
  		if isD('__ELF__'):
  			conf.env.DEST_BINFMT = 'elf'
  		elif isD('__WINNT__') or isD('__CYGWIN__') or isD('_WIN32'):
  			conf.env.DEST_BINFMT = 'pe'
  			if not conf.env.IMPLIBDIR:
  				conf.env.IMPLIBDIR = conf.env.LIBDIR # for .lib or .dll.a files
  			conf.env.LIBDIR = conf.env.BINDIR
  		elif isD('__APPLE__'):
  			conf.env.DEST_BINFMT = 'mac-o'
  
  		if not conf.env.DEST_BINFMT:
  			# Infer the binary format from the os name.
  			conf.env.DEST_BINFMT = Utils.destos_to_binfmt(conf.env.DEST_OS)
  
  		for i in MACRO_TO_DEST_CPU:
  			if isD(i):
  				conf.env.DEST_CPU = MACRO_TO_DEST_CPU[i]
  				break
  
  		Logs.debug('ccroot: dest platform: ' + ' '.join([conf.env[x] or '?' for x in ('DEST_OS', 'DEST_BINFMT', 'DEST_CPU')]))
  		if icc:
  			ver = k['__INTEL_COMPILER']
  			conf.env.CC_VERSION = (ver[:-2], ver[-2], ver[-1])
  		else:
  			if isD('__clang__') and isD('__clang_major__'):
  				conf.env.CC_VERSION = (k['__clang_major__'], k['__clang_minor__'], k['__clang_patchlevel__'])
  			else:
  				# older clang versions and gcc
  				conf.env.CC_VERSION = (k['__GNUC__'], k['__GNUC_MINOR__'], k.get('__GNUC_PATCHLEVEL__', '0'))
  	return k
  
  @conf
  def get_xlc_version(conf, cc):
  	"""
  	Returns the Aix compiler version
  
  	:raise: :py:class:`waflib.Errors.ConfigurationError`
  	"""
  	cmd = cc + ['-qversion']
  	try:
  		out, err = conf.cmd_and_log(cmd, output=0)
  	except Errors.WafError:
  		conf.fatal('Could not find xlc %r' % cmd)
  
  	# the intention is to catch the 8.0 in "IBM XL C/C++ Enterprise Edition V8.0 for AIX..."
  	for v in (r"IBM XL C/C\+\+.* V(?P<major>\d*)\.(?P<minor>\d*)",):
  		version_re = re.compile(v, re.I).search
  		match = version_re(out or err)
  		if match:
  			k = match.groupdict()
  			conf.env.CC_VERSION = (k['major'], k['minor'])
  			break
  	else:
  		conf.fatal('Could not determine the XLC version.')
  
  @conf
  def get_suncc_version(conf, cc):
  	"""
  	Returns the Sun compiler version
  
  	:raise: :py:class:`waflib.Errors.ConfigurationError`
  	"""
  	cmd = cc + ['-V']
  	try:
  		out, err = conf.cmd_and_log(cmd, output=0)
  	except Errors.WafError as e:
  		# Older versions of the compiler exit with non-zero status when reporting their version
  		if not (hasattr(e, 'returncode') and hasattr(e, 'stdout') and hasattr(e, 'stderr')):
  			conf.fatal('Could not find suncc %r' % cmd)
  		out = e.stdout
  		err = e.stderr
  
  	version = (out or err)
  	version = version.splitlines()[0]
  
  	# cc: Sun C 5.10 SunOS_i386 2009/06/03
  	# cc: Studio 12.5 Sun C++ 5.14 SunOS_sparc Beta 2015/11/17
  	# cc: WorkShop Compilers 5.0 98/12/15 C 5.0
  	version_re = re.compile(r'cc: (studio.*?|\s+)?(sun\s+(c\+\+|c)|(WorkShop\s+Compilers))?\s+(?P<major>\d*)\.(?P<minor>\d*)', re.I).search
  	match = version_re(version)
  	if match:
  		k = match.groupdict()
  		conf.env.CC_VERSION = (k['major'], k['minor'])
  	else:
  		conf.fatal('Could not determine the suncc version.')
  
  # ============ the --as-needed flag should added during the configuration, not at runtime =========
  
  @conf
  def add_as_needed(self):
  	"""
  	Adds ``--as-needed`` to the *LINKFLAGS*
  	On some platforms, it is a default flag.  In some cases (e.g., in NS-3) it is necessary to explicitly disable this feature with `-Wl,--no-as-needed` flag.
  	"""
  	if self.env.DEST_BINFMT == 'elf' and 'gcc' in (self.env.CXX_NAME, self.env.CC_NAME):
  		self.env.append_unique('LINKFLAGS', '-Wl,--as-needed')
  
  # ============ parallel configuration
  
  class cfgtask(Task.Task):
  	"""
  	A task that executes build configuration tests (calls conf.check)
  
  	Make sure to use locks if concurrent access to the same conf.env data is necessary.
  	"""
  	def __init__(self, *k, **kw):
  		Task.Task.__init__(self, *k, **kw)
  		self.run_after = set()
  
  	def display(self):
  		return ''
  
  	def runnable_status(self):
  		for x in self.run_after:
  			if not x.hasrun:
  				return Task.ASK_LATER
  		return Task.RUN_ME
  
  	def uid(self):
  		return Utils.SIG_NIL
  
  	def signature(self):
  		return Utils.SIG_NIL
  
  	def run(self):
  		conf = self.conf
  		bld = Build.BuildContext(top_dir=conf.srcnode.abspath(), out_dir=conf.bldnode.abspath())
  		bld.env = conf.env
  		bld.init_dirs()
  		bld.in_msg = 1 # suppress top-level start_msg
  		bld.logger = self.logger
  		bld.multicheck_task = self
  		args = self.args
  		try:
  			if 'func' in args:
  				bld.test(build_fun=args['func'],
  					msg=args.get('msg', ''),
  					okmsg=args.get('okmsg', ''),
  					errmsg=args.get('errmsg', ''),
  					)
  			else:
  				args['multicheck_mandatory'] = args.get('mandatory', True)
  				args['mandatory'] = True
  				try:
  					bld.check(**args)
  				finally:
  					args['mandatory'] = args['multicheck_mandatory']
  		except Exception:
  			return 1
  
  	def process(self):
  		Task.Task.process(self)
  		if 'msg' in self.args:
  			with self.generator.bld.multicheck_lock:
  				self.conf.start_msg(self.args['msg'])
  				if self.hasrun == Task.NOT_RUN:
  					self.conf.end_msg('test cancelled', 'YELLOW')
  				elif self.hasrun != Task.SUCCESS:
  					self.conf.end_msg(self.args.get('errmsg', 'no'), 'YELLOW')
  				else:
  					self.conf.end_msg(self.args.get('okmsg', 'yes'), 'GREEN')
  
  @conf
  def multicheck(self, *k, **kw):
  	"""
  	Runs configuration tests in parallel; results are printed sequentially at the end of the build
  	but each test must provide its own msg value to display a line::
  
  		def test_build(ctx):
  			ctx.in_msg = True # suppress console outputs
  			ctx.check_large_file(mandatory=False)
  
  		conf.multicheck(
  			{'header_name':'stdio.h', 'msg':'... stdio', 'uselib_store':'STDIO', 'global_define':False},
  			{'header_name':'xyztabcd.h', 'msg':'... optional xyztabcd.h', 'mandatory': False},
  			{'header_name':'stdlib.h', 'msg':'... stdlib', 'okmsg': 'aye', 'errmsg': 'nope'},
  			{'func': test_build, 'msg':'... testing an arbitrary build function', 'okmsg':'ok'},
  			msg       = 'Checking for headers in parallel',
  			mandatory = True, # mandatory tests raise an error at the end
  			run_all_tests = True, # try running all tests
  		)
  
  	The configuration tests may modify the values in conf.env in any order, and the define
  	values can affect configuration tests being executed. It is hence recommended
  	to provide `uselib_store` values with `global_define=False` to prevent such issues.
  	"""
  	self.start_msg(kw.get('msg', 'Executing %d configuration tests' % len(k)), **kw)
  
  	# Force a copy so that threads append to the same list at least
  	# no order is guaranteed, but the values should not disappear at least
  	for var in ('DEFINES', DEFKEYS):
  		self.env.append_value(var, [])
  	self.env.DEFINE_COMMENTS = self.env.DEFINE_COMMENTS or {}
  
  	# define a task object that will execute our tests
  	class par(object):
  		def __init__(self):
  			self.keep = False
  			self.task_sigs = {}
  			self.progress_bar = 0
  		def total(self):
  			return len(tasks)
  		def to_log(self, *k, **kw):
  			return
  
  	bld = par()
  	bld.keep = kw.get('run_all_tests', True)
  	bld.imp_sigs = {}
  	tasks = []
  
  	id_to_task = {}
  	for dct in k:
  		x = Task.classes['cfgtask'](bld=bld, env=None)
  		tasks.append(x)
  		x.args = dct
  		x.bld = bld
  		x.conf = self
  		x.args = dct
  
  		# bind a logger that will keep the info in memory
  		x.logger = Logs.make_mem_logger(str(id(x)), self.logger)
  
  		if 'id' in dct:
  			id_to_task[dct['id']] = x
  
  	# second pass to set dependencies with after_test/before_test
  	for x in tasks:
  		for key in Utils.to_list(x.args.get('before_tests', [])):
  			tsk = id_to_task[key]
  			if not tsk:
  				raise ValueError('No test named %r' % key)
  			tsk.run_after.add(x)
  		for key in Utils.to_list(x.args.get('after_tests', [])):
  			tsk = id_to_task[key]
  			if not tsk:
  				raise ValueError('No test named %r' % key)
  			x.run_after.add(tsk)
  
  	def it():
  		yield tasks
  		while 1:
  			yield []
  	bld.producer = p = Runner.Parallel(bld, Options.options.jobs)
  	bld.multicheck_lock = Utils.threading.Lock()
  	p.biter = it()
  
  	self.end_msg('started')
  	p.start()
  
  	# flush the logs in order into the config.log
  	for x in tasks:
  		x.logger.memhandler.flush()
  
  	self.start_msg('-> processing test results')
  	if p.error:
  		for x in p.error:
  			if getattr(x, 'err_msg', None):
  				self.to_log(x.err_msg)
  				self.end_msg('fail', color='RED')
  				raise Errors.WafError('There is an error in the library, read config.log for more information')
  
  	failure_count = 0
  	for x in tasks:
  		if x.hasrun not in (Task.SUCCESS, Task.NOT_RUN):
  			failure_count += 1
  
  	if failure_count:
  		self.end_msg(kw.get('errmsg', '%s test failed' % failure_count), color='YELLOW', **kw)
  	else:
  		self.end_msg('all ok', **kw)
  
  	for x in tasks:
  		if x.hasrun != Task.SUCCESS:
  			if x.args.get('mandatory', True):
  				self.fatal(kw.get('fatalmsg') or 'One of the tests has failed, read config.log for more information')
  
  @conf
  def check_gcc_o_space(self, mode='c'):
  	if int(self.env.CC_VERSION[0]) > 4:
  		# this is for old compilers
  		return
  	self.env.stash()
  	if mode == 'c':
  		self.env.CCLNK_TGT_F = ['-o', '']
  	elif mode == 'cxx':
  		self.env.CXXLNK_TGT_F = ['-o', '']
  	features = '%s %sshlib' % (mode, mode)
  	try:
  		self.check(msg='Checking if the -o link must be split from arguments', fragment=SNIP_EMPTY_PROGRAM, features=features)
  	except self.errors.ConfigurationError:
  		self.env.revert()
  	else:
  		self.env.commit()
  
  