Merge commit '8c96b17a5393bffee0c521c4872a9fa999048032' as 'waflib'

1 files changed, 627 insertions, 0 deletions

diff --git a/waflib/Tools/python.py b/waflib/Tools/python.py
new file mode 100644
index 0000000..25841d0
--- /dev/null
+++ b/waflib/Tools/python.py
@@ -0,0 +1,627 @@
+#!/usr/bin/env python
+# encoding: utf-8
+# Thomas Nagy, 2007-2015 (ita)
+# Gustavo Carneiro (gjc), 2007
+
+"""
+Support for Python, detect the headers and libraries and provide
+*use* variables to link C/C++ programs against them::
+
+	def options(opt):
+		opt.load('compiler_c python')
+	def configure(conf):
+		conf.load('compiler_c python')
+		conf.check_python_version((2,4,2))
+		conf.check_python_headers()
+	def build(bld):
+		bld.program(features='pyembed', source='a.c', target='myprog')
+		bld.shlib(features='pyext', source='b.c', target='mylib')
+"""
+
+import os, sys
+from waflib import Errors, Logs, Node, Options, Task, Utils
+from waflib.TaskGen import extension, before_method, after_method, feature
+from waflib.Configure import conf
+
+FRAG = '''
+#include <Python.h>
+#ifdef __cplusplus
+extern "C" {
+#endif
+	void Py_Initialize(void);
+	void Py_Finalize(void);
+#ifdef __cplusplus
+}
+#endif
+int main(int argc, char **argv)
+{
+   (void)argc; (void)argv;
+   Py_Initialize();
+   Py_Finalize();
+   return 0;
+}
+'''
+"""
+Piece of C/C++ code used in :py:func:`waflib.Tools.python.check_python_headers`
+"""
+
+INST = '''
+import sys, py_compile
+py_compile.compile(sys.argv[1], sys.argv[2], sys.argv[3], True)
+'''
+"""
+Piece of Python code used in :py:class:`waflib.Tools.python.pyo` and :py:class:`waflib.Tools.python.pyc` for byte-compiling python files
+"""
+
+DISTUTILS_IMP = ['from distutils.sysconfig import get_config_var, get_python_lib']
+
+@before_method('process_source')
+@feature('py')
+def feature_py(self):
+	"""
+	Create tasks to byte-compile .py files and install them, if requested
+	"""
+	self.install_path = getattr(self, 'install_path', '${PYTHONDIR}')
+	install_from = getattr(self, 'install_from', None)
+	if install_from and not isinstance(install_from, Node.Node):
+		install_from = self.path.find_dir(install_from)
+	self.install_from = install_from
+
+	ver = self.env.PYTHON_VERSION
+	if not ver:
+		self.bld.fatal('Installing python files requires PYTHON_VERSION, try conf.check_python_version')
+
+	if int(ver.replace('.', '')) > 31:
+		self.install_32 = True
+
+@extension('.py')
+def process_py(self, node):
+	"""
+	Add signature of .py file, so it will be byte-compiled when necessary
+	"""
+	assert(hasattr(self, 'install_path')), 'add features="py"'
+
+	# where to install the python file
+	if self.install_path:
+		if self.install_from:
+			self.add_install_files(install_to=self.install_path, install_from=node, cwd=self.install_from, relative_trick=True)
+		else:
+			self.add_install_files(install_to=self.install_path, install_from=node, relative_trick=True)
+
+	lst = []
+	if self.env.PYC:
+		lst.append('pyc')
+	if self.env.PYO:
+		lst.append('pyo')
+
+	if self.install_path:
+		if self.install_from:
+			pyd = Utils.subst_vars("%s/%s" % (self.install_path, node.path_from(self.install_from)), self.env)
+		else:
+			pyd = Utils.subst_vars("%s/%s" % (self.install_path, node.path_from(self.path)), self.env)
+	else:
+		pyd = node.abspath()
+
+	for ext in lst:
+		if self.env.PYTAG and not self.env.NOPYCACHE:
+			# __pycache__ installation for python 3.2 - PEP 3147
+			name = node.name[:-3]
+			pyobj = node.parent.get_bld().make_node('__pycache__').make_node("%s.%s.%s" % (name, self.env.PYTAG, ext))
+			pyobj.parent.mkdir()
+		else:
+			pyobj = node.change_ext(".%s" % ext)
+
+		tsk = self.create_task(ext, node, pyobj)
+		tsk.pyd = pyd
+
+		if self.install_path:
+			self.add_install_files(install_to=os.path.dirname(pyd), install_from=pyobj, cwd=node.parent.get_bld(), relative_trick=True)
+
+class pyc(Task.Task):
+	"""
+	Byte-compiling python files
+	"""
+	color = 'PINK'
+	def __str__(self):
+		node = self.outputs[0]
+		return node.path_from(node.ctx.launch_node())
+	def run(self):
+		cmd = [Utils.subst_vars('${PYTHON}', self.env), '-c', INST, self.inputs[0].abspath(), self.outputs[0].abspath(), self.pyd]
+		ret = self.generator.bld.exec_command(cmd)
+		return ret
+
+class pyo(Task.Task):
+	"""
+	Byte-compiling python files
+	"""
+	color = 'PINK'
+	def __str__(self):
+		node = self.outputs[0]
+		return node.path_from(node.ctx.launch_node())
+	def run(self):
+		cmd = [Utils.subst_vars('${PYTHON}', self.env), Utils.subst_vars('${PYFLAGS_OPT}', self.env), '-c', INST, self.inputs[0].abspath(), self.outputs[0].abspath(), self.pyd]
+		ret = self.generator.bld.exec_command(cmd)
+		return ret
+
+@feature('pyext')
+@before_method('propagate_uselib_vars', 'apply_link')
+@after_method('apply_bundle')
+def init_pyext(self):
+	"""
+	Change the values of *cshlib_PATTERN* and *cxxshlib_PATTERN* to remove the
+	*lib* prefix from library names.
+	"""
+	self.uselib = self.to_list(getattr(self, 'uselib', []))
+	if not 'PYEXT' in self.uselib:
+		self.uselib.append('PYEXT')
+	# override shlib_PATTERN set by the osx module
+	self.env.cshlib_PATTERN = self.env.cxxshlib_PATTERN = self.env.macbundle_PATTERN = self.env.pyext_PATTERN
+	self.env.fcshlib_PATTERN = self.env.dshlib_PATTERN = self.env.pyext_PATTERN
+
+	try:
+		if not self.install_path:
+			return
+	except AttributeError:
+		self.install_path = '${PYTHONARCHDIR}'
+
+@feature('pyext')
+@before_method('apply_link', 'apply_bundle')
+def set_bundle(self):
+	"""Mac-specific pyext extension that enables bundles from c_osx.py"""
+	if Utils.unversioned_sys_platform() == 'darwin':
+		self.mac_bundle = True
+
+@before_method('propagate_uselib_vars')
+@feature('pyembed')
+def init_pyembed(self):
+	"""
+	Add the PYEMBED variable.
+	"""
+	self.uselib = self.to_list(getattr(self, 'uselib', []))
+	if not 'PYEMBED' in self.uselib:
+		self.uselib.append('PYEMBED')
+
+@conf
+def get_python_variables(self, variables, imports=None):
+	"""
+	Spawn a new python process to dump configuration variables
+
+	:param variables: variables to print
+	:type variables: list of string
+	:param imports: one import by element
+	:type imports: list of string
+	:return: the variable values
+	:rtype: list of string
+	"""
+	if not imports:
+		try:
+			imports = self.python_imports
+		except AttributeError:
+			imports = DISTUTILS_IMP
+
+	program = list(imports) # copy
+	program.append('')
+	for v in variables:
+		program.append("print(repr(%s))" % v)
+	os_env = dict(os.environ)
+	try:
+		del os_env['MACOSX_DEPLOYMENT_TARGET'] # see comments in the OSX tool
+	except KeyError:
+		pass
+
+	try:
+		out = self.cmd_and_log(self.env.PYTHON + ['-c', '\n'.join(program)], env=os_env)
+	except Errors.WafError:
+		self.fatal('The distutils module is unusable: install "python-devel"?')
+	self.to_log(out)
+	return_values = []
+	for s in out.splitlines():
+		s = s.strip()
+		if not s:
+			continue
+		if s == 'None':
+			return_values.append(None)
+		elif (s[0] == "'" and s[-1] == "'") or (s[0] == '"' and s[-1] == '"'):
+			return_values.append(eval(s))
+		elif s[0].isdigit():
+			return_values.append(int(s))
+		else: break
+	return return_values
+
+@conf
+def test_pyembed(self, mode, msg='Testing pyembed configuration'):
+	self.check(header_name='Python.h', define_name='HAVE_PYEMBED', msg=msg,
+		fragment=FRAG, errmsg='Could not build a python embedded interpreter',
+		features='%s %sprogram pyembed' % (mode, mode))
+
+@conf
+def test_pyext(self, mode, msg='Testing pyext configuration'):
+	self.check(header_name='Python.h', define_name='HAVE_PYEXT', msg=msg,
+		fragment=FRAG, errmsg='Could not build python extensions',
+		features='%s %sshlib pyext' % (mode, mode))
+
+@conf
+def python_cross_compile(self, features='pyembed pyext'):
+	"""
+	For cross-compilation purposes, it is possible to bypass the normal detection and set the flags that you want:
+	PYTHON_VERSION='3.4' PYTAG='cpython34' pyext_PATTERN="%s.so" PYTHON_LDFLAGS='-lpthread -ldl' waf configure
+
+	The following variables are used:
+	PYTHON_VERSION    required
+	PYTAG             required
+	PYTHON_LDFLAGS    required
+	pyext_PATTERN     required
+	PYTHON_PYEXT_LDFLAGS
+	PYTHON_PYEMBED_LDFLAGS
+	"""
+	features = Utils.to_list(features)
+	if not ('PYTHON_LDFLAGS' in self.environ or 'PYTHON_PYEXT_LDFLAGS' in self.environ or 'PYTHON_PYEMBED_LDFLAGS' in self.environ):
+		return False
+
+	for x in 'PYTHON_VERSION PYTAG pyext_PATTERN'.split():
+		if not x in self.environ:
+			self.fatal('Please set %s in the os environment' % x)
+		else:
+			self.env[x] = self.environ[x]
+
+	xx = self.env.CXX_NAME and 'cxx' or 'c'
+	if 'pyext' in features:
+		flags = self.environ.get('PYTHON_PYEXT_LDFLAGS', self.environ.get('PYTHON_LDFLAGS'))
+		if flags is None:
+			self.fatal('No flags provided through PYTHON_PYEXT_LDFLAGS as required')
+		else:
+			self.parse_flags(flags, 'PYEXT')
+		self.test_pyext(xx)
+	if 'pyembed' in features:
+		flags = self.environ.get('PYTHON_PYEMBED_LDFLAGS', self.environ.get('PYTHON_LDFLAGS'))
+		if flags is None:
+			self.fatal('No flags provided through PYTHON_PYEMBED_LDFLAGS as required')
+		else:
+			self.parse_flags(flags, 'PYEMBED')
+		self.test_pyembed(xx)
+	return True
+
+@conf
+def check_python_headers(conf, features='pyembed pyext'):
+	"""
+	Check for headers and libraries necessary to extend or embed python by using the module *distutils*.
+	On success the environment variables xxx_PYEXT and xxx_PYEMBED are added:
+
+	* PYEXT: for compiling python extensions
+	* PYEMBED: for embedding a python interpreter
+	"""
+	features = Utils.to_list(features)
+	assert ('pyembed' in features) or ('pyext' in features), "check_python_headers features must include 'pyembed' and/or 'pyext'"
+	env = conf.env
+	if not env.CC_NAME and not env.CXX_NAME:
+		conf.fatal('load a compiler first (gcc, g++, ..)')
+
+	# bypass all the code below for cross-compilation
+	if conf.python_cross_compile(features):
+		return
+
+	if not env.PYTHON_VERSION:
+		conf.check_python_version()
+
+	pybin = env.PYTHON
+	if not pybin:
+		conf.fatal('Could not find the python executable')
+
+	# so we actually do all this for compatibility reasons and for obtaining pyext_PATTERN below
+	v = 'prefix SO LDFLAGS LIBDIR LIBPL INCLUDEPY Py_ENABLE_SHARED MACOSX_DEPLOYMENT_TARGET LDSHARED CFLAGS LDVERSION'.split()
+	try:
+		lst = conf.get_python_variables(["get_config_var('%s') or ''" % x for x in v])
+	except RuntimeError:
+		conf.fatal("Python development headers not found (-v for details).")
+
+	vals = ['%s = %r' % (x, y) for (x, y) in zip(v, lst)]
+	conf.to_log("Configuration returned from %r:\n%s\n" % (pybin, '\n'.join(vals)))
+
+	dct = dict(zip(v, lst))
+	x = 'MACOSX_DEPLOYMENT_TARGET'
+	if dct[x]:
+		env[x] = conf.environ[x] = dct[x]
+	env.pyext_PATTERN = '%s' + dct['SO'] # not a mistake
+
+
+	# Try to get pythonX.Y-config
+	num = '.'.join(env.PYTHON_VERSION.split('.')[:2])
+	conf.find_program([''.join(pybin) + '-config', 'python%s-config' % num, 'python-config-%s' % num, 'python%sm-config' % num], var='PYTHON_CONFIG', msg="python-config", mandatory=False)
+
+	if env.PYTHON_CONFIG:
+		# python2.6-config requires 3 runs
+		all_flags = [['--cflags', '--libs', '--ldflags']]
+		if sys.hexversion < 0x2070000:
+			all_flags = [[k] for k in all_flags[0]]
+
+		xx = env.CXX_NAME and 'cxx' or 'c'
+
+		if 'pyembed' in features:
+			for flags in all_flags:
+				conf.check_cfg(msg='Asking python-config for pyembed %r flags' % ' '.join(flags), path=env.PYTHON_CONFIG, package='', uselib_store='PYEMBED', args=flags)
+
+			try:
+				conf.test_pyembed(xx)
+			except conf.errors.ConfigurationError:
+				# python bug 7352
+				if dct['Py_ENABLE_SHARED'] and dct['LIBDIR']:
+					env.append_unique('LIBPATH_PYEMBED', [dct['LIBDIR']])
+					conf.test_pyembed(xx)
+				else:
+					raise
+
+		if 'pyext' in features:
+			for flags in all_flags:
+				conf.check_cfg(msg='Asking python-config for pyext %r flags' % ' '.join(flags), path=env.PYTHON_CONFIG, package='', uselib_store='PYEXT', args=flags)
+
+			try:
+				conf.test_pyext(xx)
+			except conf.errors.ConfigurationError:
+				# python bug 7352
+				if dct['Py_ENABLE_SHARED'] and dct['LIBDIR']:
+					env.append_unique('LIBPATH_PYEXT', [dct['LIBDIR']])
+					conf.test_pyext(xx)
+				else:
+					raise
+
+		conf.define('HAVE_PYTHON_H', 1)
+		return
+
+	# No python-config, do something else on windows systems
+	all_flags = dct['LDFLAGS'] + ' ' + dct['CFLAGS']
+	conf.parse_flags(all_flags, 'PYEMBED')
+
+	all_flags = dct['LDFLAGS'] + ' ' + dct['LDSHARED'] + ' ' + dct['CFLAGS']
+	conf.parse_flags(all_flags, 'PYEXT')
+
+	result = None
+	if not dct["LDVERSION"]:
+		dct["LDVERSION"] = env.PYTHON_VERSION
+
+	# further simplification will be complicated
+	for name in ('python' + dct['LDVERSION'], 'python' + env.PYTHON_VERSION + 'm', 'python' + env.PYTHON_VERSION.replace('.', '')):
+
+		# LIBPATH_PYEMBED is already set; see if it works.
+		if not result and env.LIBPATH_PYEMBED:
+			path = env.LIBPATH_PYEMBED
+			conf.to_log("\n\n# Trying default LIBPATH_PYEMBED: %r\n" % path)
+			result = conf.check(lib=name, uselib='PYEMBED', libpath=path, mandatory=False, msg='Checking for library %s in LIBPATH_PYEMBED' % name)
+
+		if not result and dct['LIBDIR']:
+			path = [dct['LIBDIR']]
+			conf.to_log("\n\n# try again with -L$python_LIBDIR: %r\n" % path)
+			result = conf.check(lib=name, uselib='PYEMBED', libpath=path, mandatory=False, msg='Checking for library %s in LIBDIR' % name)
+
+		if not result and dct['LIBPL']:
+			path = [dct['LIBPL']]
+			conf.to_log("\n\n# try again with -L$python_LIBPL (some systems don't install the python library in $prefix/lib)\n")
+			result = conf.check(lib=name, uselib='PYEMBED', libpath=path, mandatory=False, msg='Checking for library %s in python_LIBPL' % name)
+
+		if not result:
+			path = [os.path.join(dct['prefix'], "libs")]
+			conf.to_log("\n\n# try again with -L$prefix/libs, and pythonXY name rather than pythonX.Y (win32)\n")
+			result = conf.check(lib=name, uselib='PYEMBED', libpath=path, mandatory=False, msg='Checking for library %s in $prefix/libs' % name)
+
+		if result:
+			break # do not forget to set LIBPATH_PYEMBED
+
+	if result:
+		env.LIBPATH_PYEMBED = path
+		env.append_value('LIB_PYEMBED', [name])
+	else:
+		conf.to_log("\n\n### LIB NOT FOUND\n")
+
+	# under certain conditions, python extensions must link to
+	# python libraries, not just python embedding programs.
+	if Utils.is_win32 or dct['Py_ENABLE_SHARED']:
+		env.LIBPATH_PYEXT = env.LIBPATH_PYEMBED
+		env.LIB_PYEXT = env.LIB_PYEMBED
+
+	conf.to_log("Include path for Python extensions (found via distutils module): %r\n" % (dct['INCLUDEPY'],))
+	env.INCLUDES_PYEXT = [dct['INCLUDEPY']]
+	env.INCLUDES_PYEMBED = [dct['INCLUDEPY']]
+
+	# Code using the Python API needs to be compiled with -fno-strict-aliasing
+	if env.CC_NAME == 'gcc':
+		env.append_value('CFLAGS_PYEMBED', ['-fno-strict-aliasing'])
+		env.append_value('CFLAGS_PYEXT', ['-fno-strict-aliasing'])
+	if env.CXX_NAME == 'gcc':
+		env.append_value('CXXFLAGS_PYEMBED', ['-fno-strict-aliasing'])
+		env.append_value('CXXFLAGS_PYEXT', ['-fno-strict-aliasing'])
+
+	if env.CC_NAME == "msvc":
+		from distutils.msvccompiler import MSVCCompiler
+		dist_compiler = MSVCCompiler()
+		dist_compiler.initialize()
+		env.append_value('CFLAGS_PYEXT', dist_compiler.compile_options)
+		env.append_value('CXXFLAGS_PYEXT', dist_compiler.compile_options)
+		env.append_value('LINKFLAGS_PYEXT', dist_compiler.ldflags_shared)
+
+	# See if it compiles
+	conf.check(header_name='Python.h', define_name='HAVE_PYTHON_H', uselib='PYEMBED', fragment=FRAG, errmsg='Distutils not installed? Broken python installation? Get python-config now!')
+
+@conf
+def check_python_version(conf, minver=None):
+	"""
+	Check if the python interpreter is found matching a given minimum version.
+	minver should be a tuple, eg. to check for python >= 2.4.2 pass (2,4,2) as minver.
+
+	If successful, PYTHON_VERSION is defined as 'MAJOR.MINOR' (eg. '2.4')
+	of the actual python version found, and PYTHONDIR and PYTHONARCHDIR
+	are defined, pointing to the site-packages directories appropriate for
+	this python version, where modules/packages/extensions should be
+	installed.
+
+	:param minver: minimum version
+	:type minver: tuple of int
+	"""
+	assert minver is None or isinstance(minver, tuple)
+	pybin = conf.env.PYTHON
+	if not pybin:
+		conf.fatal('could not find the python executable')
+
+	# Get python version string
+	cmd = pybin + ['-c', 'import sys\nfor x in sys.version_info: print(str(x))']
+	Logs.debug('python: Running python command %r', cmd)
+	lines = conf.cmd_and_log(cmd).split()
+	assert len(lines) == 5, "found %r lines, expected 5: %r" % (len(lines), lines)
+	pyver_tuple = (int(lines[0]), int(lines[1]), int(lines[2]), lines[3], int(lines[4]))
+
+	# Compare python version with the minimum required
+	result = (minver is None) or (pyver_tuple >= minver)
+
+	if result:
+		# define useful environment variables
+		pyver = '.'.join([str(x) for x in pyver_tuple[:2]])
+		conf.env.PYTHON_VERSION = pyver
+
+		if 'PYTHONDIR' in conf.env:
+			# Check if --pythondir was specified
+			pydir = conf.env.PYTHONDIR
+		elif 'PYTHONDIR' in conf.environ:
+			# Check environment for PYTHONDIR
+			pydir = conf.environ['PYTHONDIR']
+		else:
+			# Finally, try to guess
+			if Utils.is_win32:
+				(python_LIBDEST, pydir) = conf.get_python_variables(
+					  ["get_config_var('LIBDEST') or ''",
+					   "get_python_lib(standard_lib=0) or ''"])
+			else:
+				python_LIBDEST = None
+				(pydir,) = conf.get_python_variables( ["get_python_lib(standard_lib=0, prefix=%r) or ''" % conf.env.PREFIX])
+			if python_LIBDEST is None:
+				if conf.env.LIBDIR:
+					python_LIBDEST = os.path.join(conf.env.LIBDIR, 'python' + pyver)
+				else:
+					python_LIBDEST = os.path.join(conf.env.PREFIX, 'lib', 'python' + pyver)
+
+		if 'PYTHONARCHDIR' in conf.env:
+			# Check if --pythonarchdir was specified
+			pyarchdir = conf.env.PYTHONARCHDIR
+		elif 'PYTHONARCHDIR' in conf.environ:
+			# Check environment for PYTHONDIR
+			pyarchdir = conf.environ['PYTHONARCHDIR']
+		else:
+			# Finally, try to guess
+			(pyarchdir, ) = conf.get_python_variables( ["get_python_lib(plat_specific=1, standard_lib=0, prefix=%r) or ''" % conf.env.PREFIX])
+			if not pyarchdir:
+				pyarchdir = pydir
+
+		if hasattr(conf, 'define'): # conf.define is added by the C tool, so may not exist
+			conf.define('PYTHONDIR', pydir)
+			conf.define('PYTHONARCHDIR', pyarchdir)
+
+		conf.env.PYTHONDIR = pydir
+		conf.env.PYTHONARCHDIR = pyarchdir
+
+	# Feedback
+	pyver_full = '.'.join(map(str, pyver_tuple[:3]))
+	if minver is None:
+		conf.msg('Checking for python version', pyver_full)
+	else:
+		minver_str = '.'.join(map(str, minver))
+		conf.msg('Checking for python version >= %s' % (minver_str,), pyver_full, color=result and 'GREEN' or 'YELLOW')
+
+	if not result:
+		conf.fatal('The python version is too old, expecting %r' % (minver,))
+
+PYTHON_MODULE_TEMPLATE = '''
+import %s as current_module
+version = getattr(current_module, '__version__', None)
+if version is not None:
+	print(str(version))
+else:
+	print('unknown version')
+'''
+
+@conf
+def check_python_module(conf, module_name, condition=''):
+	"""
+	Check if the selected python interpreter can import the given python module::
+
+		def configure(conf):
+			conf.check_python_module('pygccxml')
+			conf.check_python_module('re', condition="ver > num(2, 0, 4) and ver <= num(3, 0, 0)")
+
+	:param module_name: module
+	:type module_name: string
+	"""
+	msg = "Checking for python module %r" % module_name
+	if condition:
+		msg = '%s (%s)' % (msg, condition)
+	conf.start_msg(msg)
+	try:
+		ret = conf.cmd_and_log(conf.env.PYTHON + ['-c', PYTHON_MODULE_TEMPLATE % module_name])
+	except Errors.WafError:
+		conf.end_msg(False)
+		conf.fatal('Could not find the python module %r' % module_name)
+
+	ret = ret.strip()
+	if condition:
+		conf.end_msg(ret)
+		if ret == 'unknown version':
+			conf.fatal('Could not check the %s version' % module_name)
+
+		from distutils.version import LooseVersion
+		def num(*k):
+			if isinstance(k[0], int):
+				return LooseVersion('.'.join([str(x) for x in k]))
+			else:
+				return LooseVersion(k[0])
+		d = {'num': num, 'ver': LooseVersion(ret)}
+		ev = eval(condition, {}, d)
+		if not ev:
+			conf.fatal('The %s version does not satisfy the requirements' % module_name)
+	else:
+		if ret == 'unknown version':
+			conf.end_msg(True)
+		else:
+			conf.end_msg(ret)
+
+def configure(conf):
+	"""
+	Detect the python interpreter
+	"""
+	v = conf.env
+	if getattr(Options.options, 'pythondir', None):
+		v.PYTHONDIR = Options.options.pythondir
+	if getattr(Options.options, 'pythonarchdir', None):
+		v.PYTHONARCHDIR = Options.options.pythonarchdir
+	if getattr(Options.options, 'nopycache', None):
+		v.NOPYCACHE=Options.options.nopycache
+
+	if not v.PYTHON:
+		v.PYTHON = [getattr(Options.options, 'python', None) or sys.executable]
+	v.PYTHON = Utils.to_list(v.PYTHON)
+	conf.find_program('python', var='PYTHON')
+
+	v.PYFLAGS = ''
+	v.PYFLAGS_OPT = '-O'
+
+	v.PYC = getattr(Options.options, 'pyc', 1)
+	v.PYO = getattr(Options.options, 'pyo', 1)
+
+	try:
+		v.PYTAG = conf.cmd_and_log(conf.env.PYTHON + ['-c', "import imp;print(imp.get_tag())"]).strip()
+	except Errors.WafError:
+		pass
+
+def options(opt):
+	"""
+	Add python-specific options
+	"""
+	pyopt=opt.add_option_group("Python Options")
+	pyopt.add_option('--nopyc', dest = 'pyc', action='store_false', default=1,
+					 help = 'Do not install bytecode compiled .pyc files (configuration) [Default:install]')
+	pyopt.add_option('--nopyo', dest='pyo', action='store_false', default=1,
+					 help='Do not install optimised compiled .pyo files (configuration) [Default:install]')
+	pyopt.add_option('--nopycache',dest='nopycache', action='store_true',
+					 help='Do not use __pycache__ directory to install objects [Default:auto]')
+	pyopt.add_option('--python', dest="python",
+					 help='python binary to be used [Default: %s]' % sys.executable)
+	pyopt.add_option('--pythondir', dest='pythondir',
+					 help='Installation path for python modules (py, platform-independent .py and .pyc files)')
+	pyopt.add_option('--pythonarchdir', dest='pythonarchdir',
+					 help='Installation path for python extension (pyext, platform-dependent .so or .dylib files)')
+