Adding upstream version 2.4.2.upstream/2.4.2upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 792 insertions, 0 deletions

diff --git a/third_party/waf/waflib/Tools/ccroot.py b/third_party/waf/waflib/Tools/ccroot.py
new file mode 100644
index 0000000..76deff5
--- /dev/null
+++ b/third_party/waf/waflib/Tools/ccroot.py
@@ -0,0 +1,792 @@
+#!/usr/bin/env python
+# encoding: utf-8
+# Thomas Nagy, 2005-2018 (ita)
+
+"""
+Classes and methods shared by tools providing support for C-like language such
+as C/C++/D/Assembly/Go (this support module is almost never used alone).
+"""
+
+import os, re
+from waflib import Task, Utils, Node, Errors, Logs
+from waflib.TaskGen import after_method, before_method, feature, taskgen_method, extension
+from waflib.Tools import c_aliases, c_preproc, c_config, c_osx, c_tests
+from waflib.Configure import conf
+
+SYSTEM_LIB_PATHS = ['/usr/lib64', '/usr/lib', '/usr/local/lib64', '/usr/local/lib']
+
+USELIB_VARS = Utils.defaultdict(set)
+"""
+Mapping for features to :py:class:`waflib.ConfigSet.ConfigSet` variables. See :py:func:`waflib.Tools.ccroot.propagate_uselib_vars`.
+"""
+
+USELIB_VARS['c']        = set(['INCLUDES', 'FRAMEWORKPATH', 'DEFINES', 'CPPFLAGS', 'CCDEPS', 'CFLAGS', 'ARCH'])
+USELIB_VARS['cxx']      = set(['INCLUDES', 'FRAMEWORKPATH', 'DEFINES', 'CPPFLAGS', 'CXXDEPS', 'CXXFLAGS', 'ARCH'])
+USELIB_VARS['d']        = set(['INCLUDES', 'DFLAGS'])
+USELIB_VARS['includes'] = set(['INCLUDES', 'FRAMEWORKPATH', 'ARCH'])
+
+USELIB_VARS['cprogram'] = USELIB_VARS['cxxprogram'] = set(['LIB', 'STLIB', 'LIBPATH', 'STLIBPATH', 'LINKFLAGS', 'RPATH', 'LINKDEPS', 'FRAMEWORK', 'FRAMEWORKPATH', 'ARCH', 'LDFLAGS'])
+USELIB_VARS['cshlib']   = USELIB_VARS['cxxshlib']   = set(['LIB', 'STLIB', 'LIBPATH', 'STLIBPATH', 'LINKFLAGS', 'RPATH', 'LINKDEPS', 'FRAMEWORK', 'FRAMEWORKPATH', 'ARCH', 'LDFLAGS'])
+USELIB_VARS['cstlib']   = USELIB_VARS['cxxstlib']   = set(['ARFLAGS', 'LINKDEPS'])
+
+USELIB_VARS['dprogram'] = set(['LIB', 'STLIB', 'LIBPATH', 'STLIBPATH', 'LINKFLAGS', 'RPATH', 'LINKDEPS'])
+USELIB_VARS['dshlib']   = set(['LIB', 'STLIB', 'LIBPATH', 'STLIBPATH', 'LINKFLAGS', 'RPATH', 'LINKDEPS'])
+USELIB_VARS['dstlib']   = set(['ARFLAGS', 'LINKDEPS'])
+
+USELIB_VARS['asm'] = set(['ASFLAGS'])
+
+# =================================================================================================
+
+@taskgen_method
+def create_compiled_task(self, name, node):
+	"""
+	Create the compilation task: c, cxx, asm, etc. The output node is created automatically (object file with a typical **.o** extension).
+	The task is appended to the list *compiled_tasks* which is then used by :py:func:`waflib.Tools.ccroot.apply_link`
+
+	:param name: name of the task class
+	:type name: string
+	:param node: the file to compile
+	:type node: :py:class:`waflib.Node.Node`
+	:return: The task created
+	:rtype: :py:class:`waflib.Task.Task`
+	"""
+	out = '%s.%d.o' % (node.name, self.idx)
+	task = self.create_task(name, node, node.parent.find_or_declare(out))
+	try:
+		self.compiled_tasks.append(task)
+	except AttributeError:
+		self.compiled_tasks = [task]
+	return task
+
+@taskgen_method
+def to_incnodes(self, inlst):
+	"""
+	Task generator method provided to convert a list of string/nodes into a list of includes folders.
+
+	The paths are assumed to be relative to the task generator path, except if they begin by **#**
+	in which case they are searched from the top-level directory (``bld.srcnode``).
+	The folders are simply assumed to be existing.
+
+	The node objects in the list are returned in the output list. The strings are converted
+	into node objects if possible. The node is searched from the source directory, and if a match is found,
+	the equivalent build directory is created and added to the returned list too. When a folder cannot be found, it is ignored.
+
+	:param inlst: list of folders
+	:type inlst: space-delimited string or a list of string/nodes
+	:rtype: list of :py:class:`waflib.Node.Node`
+	:return: list of include folders as nodes
+	"""
+	lst = []
+	seen = set()
+	for x in self.to_list(inlst):
+		if x in seen or not x:
+			continue
+		seen.add(x)
+
+		# with a real lot of targets, it is sometimes interesting to cache the results below
+		if isinstance(x, Node.Node):
+			lst.append(x)
+		else:
+			if os.path.isabs(x):
+				lst.append(self.bld.root.make_node(x) or x)
+			else:
+				if x[0] == '#':
+					p = self.bld.bldnode.make_node(x[1:])
+					v = self.bld.srcnode.make_node(x[1:])
+				else:
+					p = self.path.get_bld().make_node(x)
+					v = self.path.make_node(x)
+				if p.is_child_of(self.bld.bldnode):
+					p.mkdir()
+				lst.append(p)
+				lst.append(v)
+	return lst
+
+@feature('c', 'cxx', 'd', 'asm', 'fc', 'includes')
+@after_method('propagate_uselib_vars', 'process_source')
+def apply_incpaths(self):
+	"""
+	Task generator method that processes the attribute *includes*::
+
+		tg = bld(features='includes', includes='.')
+
+	The folders only need to be relative to the current directory, the equivalent build directory is
+	added automatically (for headers created in the build directory). This enables using a build directory
+	or not (``top == out``).
+
+	This method will add a list of nodes read by :py:func:`waflib.Tools.ccroot.to_incnodes` in ``tg.env.INCPATHS``,
+	and the list of include paths in ``tg.env.INCLUDES``.
+	"""
+
+	lst = self.to_incnodes(self.to_list(getattr(self, 'includes', [])) + self.env.INCLUDES)
+	self.includes_nodes = lst
+	cwd = self.get_cwd()
+	self.env.INCPATHS = [x.path_from(cwd) for x in lst]
+
+class link_task(Task.Task):
+	"""
+	Base class for all link tasks. A task generator is supposed to have at most one link task bound in the attribute *link_task*. See :py:func:`waflib.Tools.ccroot.apply_link`.
+
+	.. inheritance-diagram:: waflib.Tools.ccroot.stlink_task waflib.Tools.c.cprogram waflib.Tools.c.cshlib waflib.Tools.cxx.cxxstlib  waflib.Tools.cxx.cxxprogram waflib.Tools.cxx.cxxshlib waflib.Tools.d.dprogram waflib.Tools.d.dshlib waflib.Tools.d.dstlib waflib.Tools.ccroot.fake_shlib waflib.Tools.ccroot.fake_stlib waflib.Tools.asm.asmprogram waflib.Tools.asm.asmshlib waflib.Tools.asm.asmstlib
+	  :top-classes: waflib.Tools.ccroot.link_task
+	"""
+	color   = 'YELLOW'
+
+	weight  = 3
+	"""Try to process link tasks as early as possible"""
+
+	inst_to = None
+	"""Default installation path for the link task outputs, or None to disable"""
+
+	chmod   = Utils.O755
+	"""Default installation mode for the link task outputs"""
+
+	def add_target(self, target):
+		"""
+		Process the *target* attribute to add the platform-specific prefix/suffix such as *.so* or *.exe*.
+		The settings are retrieved from ``env.clsname_PATTERN``
+		"""
+		if isinstance(target, str):
+			base = self.generator.path
+			if target.startswith('#'):
+				# for those who like flat structures
+				target = target[1:]
+				base = self.generator.bld.bldnode
+
+			pattern = self.env[self.__class__.__name__ + '_PATTERN']
+			if not pattern:
+				pattern = '%s'
+			folder, name = os.path.split(target)
+
+			if self.__class__.__name__.find('shlib') > 0 and getattr(self.generator, 'vnum', None):
+				nums = self.generator.vnum.split('.')
+				if self.env.DEST_BINFMT == 'pe':
+					# include the version in the dll file name,
+					# the import lib file name stays unversioned.
+					name = name + '-' + nums[0]
+				elif self.env.DEST_OS == 'openbsd':
+					pattern = '%s.%s' % (pattern, nums[0])
+					if len(nums) >= 2:
+						pattern += '.%s' % nums[1]
+
+			if folder:
+				tmp = folder + os.sep + pattern % name
+			else:
+				tmp = pattern % name
+			target = base.find_or_declare(tmp)
+		self.set_outputs(target)
+
+	def exec_command(self, *k, **kw):
+		ret = super(link_task, self).exec_command(*k, **kw)
+		if not ret and self.env.DO_MANIFEST:
+			ret = self.exec_mf()
+		return ret
+
+	def exec_mf(self):
+		"""
+		Create manifest files for VS-like compilers (msvc, ifort, ...)
+		"""
+		if not self.env.MT:
+			return 0
+
+		manifest = None
+		for out_node in self.outputs:
+			if out_node.name.endswith('.manifest'):
+				manifest = out_node.abspath()
+				break
+		else:
+			# Should never get here.  If we do, it means the manifest file was
+			# never added to the outputs list, thus we don't have a manifest file
+			# to embed, so we just return.
+			return 0
+
+		# embedding mode. Different for EXE's and DLL's.
+		# see: http://msdn2.microsoft.com/en-us/library/ms235591(VS.80).aspx
+		mode = ''
+		for x in Utils.to_list(self.generator.features):
+			if x in ('cprogram', 'cxxprogram', 'fcprogram', 'fcprogram_test'):
+				mode = 1
+			elif x in ('cshlib', 'cxxshlib', 'fcshlib'):
+				mode = 2
+
+		Logs.debug('msvc: embedding manifest in mode %r', mode)
+
+		lst = [] + self.env.MT
+		lst.extend(Utils.to_list(self.env.MTFLAGS))
+		lst.extend(['-manifest', manifest])
+		lst.append('-outputresource:%s;%s' % (self.outputs[0].abspath(), mode))
+
+		return super(link_task, self).exec_command(lst)
+
+class stlink_task(link_task):
+	"""
+	Base for static link tasks, which use *ar* most of the time.
+	The target is always removed before being written.
+	"""
+	run_str = '${AR} ${ARFLAGS} ${AR_TGT_F}${TGT} ${AR_SRC_F}${SRC}'
+
+	chmod   = Utils.O644
+	"""Default installation mode for the static libraries"""
+
+def rm_tgt(cls):
+	old = cls.run
+	def wrap(self):
+		try:
+			os.remove(self.outputs[0].abspath())
+		except OSError:
+			pass
+		return old(self)
+	setattr(cls, 'run', wrap)
+rm_tgt(stlink_task)
+
+@feature('skip_stlib_link_deps')
+@before_method('process_use')
+def apply_skip_stlib_link_deps(self):
+	"""
+	This enables an optimization in the :py:func:wafilb.Tools.ccroot.processes_use: method that skips dependency and
+	link flag optimizations for targets that generate static libraries (via the :py:class:Tools.ccroot.stlink_task task).
+	The actual behavior is implemented in :py:func:wafilb.Tools.ccroot.processes_use: method so this feature only tells waf
+	to enable the new behavior.
+	"""
+	self.env.SKIP_STLIB_LINK_DEPS = True
+
+@feature('c', 'cxx', 'd', 'fc', 'asm')
+@after_method('process_source')
+def apply_link(self):
+	"""
+	Collect the tasks stored in ``compiled_tasks`` (created by :py:func:`waflib.Tools.ccroot.create_compiled_task`), and
+	use the outputs for a new instance of :py:class:`waflib.Tools.ccroot.link_task`. The class to use is the first link task
+	matching a name from the attribute *features*, for example::
+
+			def build(bld):
+				tg = bld(features='cxx cxxprogram cprogram', source='main.c', target='app')
+
+	will create the task ``tg.link_task`` as a new instance of :py:class:`waflib.Tools.cxx.cxxprogram`
+	"""
+
+	for x in self.features:
+		if x == 'cprogram' and 'cxx' in self.features: # limited compat
+			x = 'cxxprogram'
+		elif x == 'cshlib' and 'cxx' in self.features:
+			x = 'cxxshlib'
+
+		if x in Task.classes:
+			if issubclass(Task.classes[x], link_task):
+				link = x
+				break
+	else:
+		return
+
+	objs = [t.outputs[0] for t in getattr(self, 'compiled_tasks', [])]
+	self.link_task = self.create_task(link, objs)
+	self.link_task.add_target(self.target)
+
+	# remember that the install paths are given by the task generators
+	try:
+		inst_to = self.install_path
+	except AttributeError:
+		inst_to = self.link_task.inst_to
+	if inst_to:
+		# install a copy of the node list we have at this moment (implib not added)
+		self.install_task = self.add_install_files(
+			install_to=inst_to, install_from=self.link_task.outputs[:],
+			chmod=self.link_task.chmod, task=self.link_task)
+
+@taskgen_method
+def use_rec(self, name, **kw):
+	"""
+	Processes the ``use`` keyword recursively. This method is kind of private and only meant to be used from ``process_use``
+	"""
+
+	if name in self.tmp_use_not or name in self.tmp_use_seen:
+		return
+
+	try:
+		y = self.bld.get_tgen_by_name(name)
+	except Errors.WafError:
+		self.uselib.append(name)
+		self.tmp_use_not.add(name)
+		return
+
+	self.tmp_use_seen.append(name)
+	y.post()
+
+	# bind temporary attributes on the task generator
+	y.tmp_use_objects = objects = kw.get('objects', True)
+	y.tmp_use_stlib   = stlib   = kw.get('stlib', True)
+	try:
+		link_task = y.link_task
+	except AttributeError:
+		y.tmp_use_var = ''
+	else:
+		objects = False
+		if not isinstance(link_task, stlink_task):
+			stlib = False
+			y.tmp_use_var = 'LIB'
+		else:
+			y.tmp_use_var = 'STLIB'
+
+	p = self.tmp_use_prec
+	for x in self.to_list(getattr(y, 'use', [])):
+		if self.env["STLIB_" + x]:
+			continue
+		try:
+			p[x].append(name)
+		except KeyError:
+			p[x] = [name]
+		self.use_rec(x, objects=objects, stlib=stlib)
+
+@feature('c', 'cxx', 'd', 'use', 'fc')
+@before_method('apply_incpaths', 'propagate_uselib_vars')
+@after_method('apply_link', 'process_source')
+def process_use(self):
+	"""
+	Process the ``use`` attribute which contains a list of task generator names::
+
+		def build(bld):
+			bld.shlib(source='a.c', target='lib1')
+			bld.program(source='main.c', target='app', use='lib1')
+
+	See :py:func:`waflib.Tools.ccroot.use_rec`.
+	"""
+
+	use_not = self.tmp_use_not = set()
+	self.tmp_use_seen = [] # we would like an ordered set
+	use_prec = self.tmp_use_prec = {}
+	self.uselib = self.to_list(getattr(self, 'uselib', []))
+	self.includes = self.to_list(getattr(self, 'includes', []))
+	names = self.to_list(getattr(self, 'use', []))
+
+	for x in names:
+		self.use_rec(x)
+
+	for x in use_not:
+		if x in use_prec:
+			del use_prec[x]
+
+	# topological sort
+	out = self.tmp_use_sorted = []
+	tmp = []
+	for x in self.tmp_use_seen:
+		for k in use_prec.values():
+			if x in k:
+				break
+		else:
+			tmp.append(x)
+
+	while tmp:
+		e = tmp.pop()
+		out.append(e)
+		try:
+			nlst = use_prec[e]
+		except KeyError:
+			pass
+		else:
+			del use_prec[e]
+			for x in nlst:
+				for y in use_prec:
+					if x in use_prec[y]:
+						break
+				else:
+					tmp.append(x)
+	if use_prec:
+		raise Errors.WafError('Cycle detected in the use processing %r' % use_prec)
+	out.reverse()
+
+	link_task = getattr(self, 'link_task', None)
+	for x in out:
+		y = self.bld.get_tgen_by_name(x)
+		var = y.tmp_use_var
+		if var and link_task:
+			if self.env.SKIP_STLIB_LINK_DEPS and isinstance(link_task, stlink_task):
+				# If the skip_stlib_link_deps feature is enabled then we should
+				# avoid adding lib deps to the stlink_task instance.
+				pass
+			elif var == 'LIB' or y.tmp_use_stlib or x in names:
+				self.env.append_value(var, [y.target[y.target.rfind(os.sep) + 1:]])
+				self.link_task.dep_nodes.extend(y.link_task.outputs)
+				tmp_path = y.link_task.outputs[0].parent.path_from(self.get_cwd())
+				self.env.append_unique(var + 'PATH', [tmp_path])
+		else:
+			if y.tmp_use_objects:
+				self.add_objects_from_tgen(y)
+
+		if getattr(y, 'export_includes', None):
+			# self.includes may come from a global variable #2035
+			self.includes = self.includes + y.to_incnodes(y.export_includes)
+
+		if getattr(y, 'export_defines', None):
+			self.env.append_value('DEFINES', self.to_list(y.export_defines))
+
+
+	# and finally, add the use variables (no recursion needed)
+	for x in names:
+		try:
+			y = self.bld.get_tgen_by_name(x)
+		except Errors.WafError:
+			if not self.env['STLIB_' + x] and not x in self.uselib:
+				self.uselib.append(x)
+		else:
+			for k in self.to_list(getattr(y, 'use', [])):
+				if not self.env['STLIB_' + k] and not k in self.uselib:
+					self.uselib.append(k)
+
+@taskgen_method
+def accept_node_to_link(self, node):
+	"""
+	PRIVATE INTERNAL USE ONLY
+	"""
+	return not node.name.endswith('.pdb')
+
+@taskgen_method
+def add_objects_from_tgen(self, tg):
+	"""
+	Add the objects from the depending compiled tasks as link task inputs.
+
+	Some objects are filtered: for instance, .pdb files are added
+	to the compiled tasks but not to the link tasks (to avoid errors)
+	PRIVATE INTERNAL USE ONLY
+	"""
+	try:
+		link_task = self.link_task
+	except AttributeError:
+		pass
+	else:
+		for tsk in getattr(tg, 'compiled_tasks', []):
+			for x in tsk.outputs:
+				if self.accept_node_to_link(x):
+					link_task.inputs.append(x)
+
+@taskgen_method
+def get_uselib_vars(self):
+	"""
+	:return: the *uselib* variables associated to the *features* attribute (see :py:attr:`waflib.Tools.ccroot.USELIB_VARS`)
+	:rtype: list of string
+	"""
+	_vars = set()
+	for x in self.features:
+		if x in USELIB_VARS:
+			_vars |= USELIB_VARS[x]
+	return _vars
+
+@feature('c', 'cxx', 'd', 'fc', 'javac', 'cs', 'uselib', 'asm')
+@after_method('process_use')
+def propagate_uselib_vars(self):
+	"""
+	Process uselib variables for adding flags. For example, the following target::
+
+		def build(bld):
+			bld.env.AFLAGS_aaa = ['bar']
+			from waflib.Tools.ccroot import USELIB_VARS
+			USELIB_VARS['aaa'] = ['AFLAGS']
+
+			tg = bld(features='aaa', aflags='test')
+
+	The *aflags* attribute will be processed and this method will set::
+
+			tg.env.AFLAGS = ['bar', 'test']
+	"""
+	_vars = self.get_uselib_vars()
+	env = self.env
+	app = env.append_value
+	feature_uselib = self.features + self.to_list(getattr(self, 'uselib', []))
+	for var in _vars:
+		y = var.lower()
+		val = getattr(self, y, [])
+		if val:
+			app(var, self.to_list(val))
+
+		for x in feature_uselib:
+			val = env['%s_%s' % (var, x)]
+			if val:
+				app(var, val)
+
+# ============ the code above must not know anything about import libs ==========
+
+@feature('cshlib', 'cxxshlib', 'fcshlib')
+@after_method('apply_link')
+def apply_implib(self):
+	"""
+	Handle dlls and their import libs on Windows-like systems.
+
+	A ``.dll.a`` file called *import library* is generated.
+	It must be installed as it is required for linking the library.
+	"""
+	if not self.env.DEST_BINFMT == 'pe':
+		return
+
+	dll = self.link_task.outputs[0]
+	if isinstance(self.target, Node.Node):
+		name = self.target.name
+	else:
+		name = os.path.split(self.target)[1]
+	implib = self.env.implib_PATTERN % name
+	implib = dll.parent.find_or_declare(implib)
+	self.env.append_value('LINKFLAGS', self.env.IMPLIB_ST % implib.bldpath())
+	self.link_task.outputs.append(implib)
+
+	if getattr(self, 'defs', None) and self.env.DEST_BINFMT == 'pe':
+		node = self.path.find_resource(self.defs)
+		if not node:
+			raise Errors.WafError('invalid def file %r' % self.defs)
+		if self.env.def_PATTERN:
+			self.env.append_value('LINKFLAGS', self.env.def_PATTERN % node.path_from(self.get_cwd()))
+			self.link_task.dep_nodes.append(node)
+		else:
+			# gcc for windows takes *.def file as input without any special flag
+			self.link_task.inputs.append(node)
+
+	# where to put the import library
+	if getattr(self, 'install_task', None):
+		try:
+			# user has given a specific installation path for the import library
+			inst_to = self.install_path_implib
+		except AttributeError:
+			try:
+				# user has given an installation path for the main library, put the import library in it
+				inst_to = self.install_path
+			except AttributeError:
+				# else, put the library in BINDIR and the import library in LIBDIR
+				inst_to = '${IMPLIBDIR}'
+				self.install_task.install_to = '${BINDIR}'
+				if not self.env.IMPLIBDIR:
+					self.env.IMPLIBDIR = self.env.LIBDIR
+		self.implib_install_task = self.add_install_files(install_to=inst_to, install_from=implib,
+			chmod=self.link_task.chmod, task=self.link_task)
+
+# ============ the code above must not know anything about vnum processing on unix platforms =========
+
+re_vnum = re.compile('^([1-9]\\d*|0)([.]([1-9]\\d*|0)){0,2}?$')
+@feature('cshlib', 'cxxshlib', 'dshlib', 'fcshlib', 'vnum')
+@after_method('apply_link', 'propagate_uselib_vars')
+def apply_vnum(self):
+	"""
+	Enforce version numbering on shared libraries. The valid version numbers must have either zero or two dots::
+
+		def build(bld):
+			bld.shlib(source='a.c', target='foo', vnum='14.15.16')
+
+	In this example on Linux platform, ``libfoo.so`` is installed as ``libfoo.so.14.15.16``, and the following symbolic links are created:
+
+	* ``libfoo.so    → libfoo.so.14.15.16``
+	* ``libfoo.so.14 → libfoo.so.14.15.16``
+
+	By default, the library will be assigned SONAME ``libfoo.so.14``, effectively declaring ABI compatibility between all minor and patch releases for the major version of the library.  When necessary, the compatibility can be explicitly defined using `cnum` parameter:
+
+		def build(bld):
+			bld.shlib(source='a.c', target='foo', vnum='14.15.16', cnum='14.15')
+
+	In this case, the assigned SONAME will be ``libfoo.so.14.15`` with ABI compatibility only between path releases for a specific major and minor version of the library.
+
+	On OS X platform, install-name parameter will follow the above logic for SONAME with exception that it also specifies an absolute path (based on install_path) of the library.
+	"""
+	if not getattr(self, 'vnum', '') or os.name != 'posix' or self.env.DEST_BINFMT not in ('elf', 'mac-o'):
+		return
+
+	link = self.link_task
+	if not re_vnum.match(self.vnum):
+		raise Errors.WafError('Invalid vnum %r for target %r' % (self.vnum, getattr(self, 'name', self)))
+	nums = self.vnum.split('.')
+	node = link.outputs[0]
+
+	cnum = getattr(self, 'cnum', str(nums[0]))
+	cnums = cnum.split('.')
+	if len(cnums)>len(nums) or nums[0:len(cnums)] != cnums:
+		raise Errors.WafError('invalid compatibility version %s' % cnum)
+
+	libname = node.name
+	if libname.endswith('.dylib'):
+		name3 = libname.replace('.dylib', '.%s.dylib' % self.vnum)
+		name2 = libname.replace('.dylib', '.%s.dylib' % cnum)
+	else:
+		name3 = libname + '.' + self.vnum
+		name2 = libname + '.' + cnum
+
+	# add the so name for the ld linker - to disable, just unset env.SONAME_ST
+	if self.env.SONAME_ST:
+		v = self.env.SONAME_ST % name2
+		self.env.append_value('LINKFLAGS', v.split())
+
+	# the following task is just to enable execution from the build dir :-/
+	if self.env.DEST_OS != 'openbsd':
+		outs = [node.parent.make_node(name3)]
+		if name2 != name3:
+			outs.append(node.parent.make_node(name2))
+		self.create_task('vnum', node, outs)
+
+	if getattr(self, 'install_task', None):
+		self.install_task.hasrun = Task.SKIPPED
+		self.install_task.no_errcheck_out = True
+		path = self.install_task.install_to
+		if self.env.DEST_OS == 'openbsd':
+			libname = self.link_task.outputs[0].name
+			t1 = self.add_install_as(install_to='%s/%s' % (path, libname), install_from=node, chmod=self.link_task.chmod)
+			self.vnum_install_task = (t1,)
+		else:
+			t1 = self.add_install_as(install_to=path + os.sep + name3, install_from=node, chmod=self.link_task.chmod)
+			t3 = self.add_symlink_as(install_to=path + os.sep + libname, install_from=name3)
+			if name2 != name3:
+				t2 = self.add_symlink_as(install_to=path + os.sep + name2, install_from=name3)
+				self.vnum_install_task = (t1, t2, t3)
+			else:
+				self.vnum_install_task = (t1, t3)
+
+	if '-dynamiclib' in self.env.LINKFLAGS:
+		# this requires after(propagate_uselib_vars)
+		try:
+			inst_to = self.install_path
+		except AttributeError:
+			inst_to = self.link_task.inst_to
+		if inst_to:
+			p = Utils.subst_vars(inst_to, self.env)
+			path = os.path.join(p, name2)
+			self.env.append_value('LINKFLAGS', ['-install_name', path])
+			self.env.append_value('LINKFLAGS', '-Wl,-compatibility_version,%s' % cnum)
+			self.env.append_value('LINKFLAGS', '-Wl,-current_version,%s' % self.vnum)
+
+class vnum(Task.Task):
+	"""
+	Create the symbolic links for a versioned shared library. Instances are created by :py:func:`waflib.Tools.ccroot.apply_vnum`
+	"""
+	color = 'CYAN'
+	ext_in = ['.bin']
+	def keyword(self):
+		return 'Symlinking'
+	def run(self):
+		for x in self.outputs:
+			path = x.abspath()
+			try:
+				os.remove(path)
+			except OSError:
+				pass
+
+			try:
+				os.symlink(self.inputs[0].name, path)
+			except OSError:
+				return 1
+
+class fake_shlib(link_task):
+	"""
+	Task used for reading a system library and adding the dependency on it
+	"""
+	def runnable_status(self):
+		for t in self.run_after:
+			if not t.hasrun:
+				return Task.ASK_LATER
+		return Task.SKIP_ME
+
+class fake_stlib(stlink_task):
+	"""
+	Task used for reading a system library and adding the dependency on it
+	"""
+	def runnable_status(self):
+		for t in self.run_after:
+			if not t.hasrun:
+				return Task.ASK_LATER
+		return Task.SKIP_ME
+
+@conf
+def read_shlib(self, name, paths=[], export_includes=[], export_defines=[]):
+	"""
+	Read a system shared library, enabling its use as a local library. Will trigger a rebuild if the file changes::
+
+		def build(bld):
+			bld.read_shlib('m')
+			bld.program(source='main.c', use='m')
+	"""
+	return self(name=name, features='fake_lib', lib_paths=paths, lib_type='shlib', export_includes=export_includes, export_defines=export_defines)
+
+@conf
+def read_stlib(self, name, paths=[], export_includes=[], export_defines=[]):
+	"""
+	Read a system static library, enabling a use as a local library. Will trigger a rebuild if the file changes.
+	"""
+	return self(name=name, features='fake_lib', lib_paths=paths, lib_type='stlib', export_includes=export_includes, export_defines=export_defines)
+
+lib_patterns = {
+	'shlib' : ['lib%s.so', '%s.so', 'lib%s.dylib', 'lib%s.dll', '%s.dll'],
+	'stlib' : ['lib%s.a', '%s.a', 'lib%s.dll', '%s.dll', 'lib%s.lib', '%s.lib'],
+}
+
+@feature('fake_lib')
+def process_lib(self):
+	"""
+	Find the location of a foreign library. Used by :py:class:`waflib.Tools.ccroot.read_shlib` and :py:class:`waflib.Tools.ccroot.read_stlib`.
+	"""
+	node = None
+
+	names = [x % self.name for x in lib_patterns[self.lib_type]]
+	for x in self.lib_paths + [self.path] + SYSTEM_LIB_PATHS:
+		if not isinstance(x, Node.Node):
+			x = self.bld.root.find_node(x) or self.path.find_node(x)
+			if not x:
+				continue
+
+		for y in names:
+			node = x.find_node(y)
+			if node:
+				try:
+					Utils.h_file(node.abspath())
+				except EnvironmentError:
+					raise ValueError('Could not read %r' % y)
+				break
+		else:
+			continue
+		break
+	else:
+		raise Errors.WafError('could not find library %r' % self.name)
+	self.link_task = self.create_task('fake_%s' % self.lib_type, [], [node])
+	self.target = self.name
+
+
+class fake_o(Task.Task):
+	def runnable_status(self):
+		return Task.SKIP_ME
+
+@extension('.o', '.obj')
+def add_those_o_files(self, node):
+	tsk = self.create_task('fake_o', [], node)
+	try:
+		self.compiled_tasks.append(tsk)
+	except AttributeError:
+		self.compiled_tasks = [tsk]
+
+@feature('fake_obj')
+@before_method('process_source')
+def process_objs(self):
+	"""
+	Puts object files in the task generator outputs
+	"""
+	for node in self.to_nodes(self.source):
+		self.add_those_o_files(node)
+	self.source = []
+
+@conf
+def read_object(self, obj):
+	"""
+	Read an object file, enabling injection in libs/programs. Will trigger a rebuild if the file changes.
+
+	:param obj: object file path, as string or Node
+	"""
+	if not isinstance(obj, self.path.__class__):
+		obj = self.path.find_resource(obj)
+	return self(features='fake_obj', source=obj, name=obj.name)
+
+@feature('cxxprogram', 'cprogram')
+@after_method('apply_link', 'process_use')
+def set_full_paths_hpux(self):
+	"""
+	On hp-ux, extend the libpaths and static library paths to absolute paths
+	"""
+	if self.env.DEST_OS != 'hp-ux':
+		return
+	base = self.bld.bldnode.abspath()
+	for var in ['LIBPATH', 'STLIBPATH']:
+		lst = []
+		for x in self.env[var]:
+			if x.startswith('/'):
+				lst.append(x)
+			else:
+				lst.append(os.path.normpath(os.path.join(base, x)))
+		self.env[var] = lst
+