waflib: Add check_cxx_func() and check_c_func()

demos/c++/wscript

@@ -16,6 +16,7 @@ def options(opt):
 def configure(conf):
 	conf.load('compiler_cxx')
 	conf.check(header_name='stdio.h', features='cxx cxxprogram', mandatory=False)
+	conf.check_cxx_func('memcpy')
 
 def build(bld):
 	bld.shlib(source='a.cpp', target='mylib', vnum='9.8.7')

demos/c/wscript

@@ -41,6 +41,7 @@ def configure(conf):
 	conf.check(lib='m', cflags='-Wall', defines=['var=foo', 'x=y'], uselib_store='M', mandatory=False)
 	conf.check_large_file(mandatory=False)
 	conf.check_inline()
+	conf.check_c_func('memcpy')
 
 	endianness = conf.check_endianness()
 	conf.define_cond("BIG_ENDIAN", endianness == "big")

docs/sphinx/confmap.rst

@@ -33,6 +33,10 @@ Configuration methods
 
 * check_
 
+.. _check_c_func: tools/c_config.html#waflib.Tools.c_config.check_c_func
+
+* check_c_func_
+
 .. _check_cc: tools/c_config.html#waflib.Tools.c_config.check_cc
 
 * check_cc_
@@ -45,6 +49,10 @@ Configuration methods
 
 * check_cxx_
 
+.. _check_cxx_func: tools/c_config.html#waflib.Tools.c_config.check_cxx_func
+
+* check_cxx_func_
+
 .. _check_dlibrary: tools/d_config.html#waflib.Tools.d_config.check_dlibrary
 
 * check_dlibrary_

waflib/Tools/c_config.py

@@ -26,6 +26,32 @@ int main(int argc, char **argv) {
 }
 '''
 
+CHECK_FUNC_FRAGMENT = '''
+#define func innocuous_func
+
+#ifdef __STDC__
+#include <limits.h>
+#else
+#include <assert.h>
+#endif
+
+#undef func
+
+#ifdef __cplusplus
+extern "C"
+#endif
+char func();
+
+#if defined __stub_func || defined __stub___func
+#error "stub only"
+#endif
+
+int main(int argc, char **argv) {
+	(void)argc; (void)argv;
+	return func();
+}
+'''
+
 MACRO_TO_DESTOS = {
 '__linux__'                                      : 'linux',
 '__GNU__'                                        : 'gnu', # hurd
@@ -709,6 +735,56 @@ def check_cc(self, *k, **kw):
 	kw['compiler'] = 'c'
 	return self.check(*k, **kw)
 
+def check_func(function_name, **kw):
+	kw['define_name'] = 'HAVE_' + function_name.upper()
+	kw['fragment'] = CHECK_FUNC_FRAGMENT.replace('func', function_name)
+	kw['msg'] = 'Checking for ' + function_name
+	return kw;
+
+@conf
+def check_cxx_func(self, function_name, *k, **kw):
+	"""
+	Checks whether the library function specified by ``function_name``
+	exists.  This check is similar to the Autoconf AC_CHECK_FUNCS() macro.
+	Compiles and links a test program referencing the ``function_name``
+	symbol via a function call using the C++ compiler.  Defines
+	``HAVE_FUNCTION_NAME`` to 1 in the configuration header if the check
+	was successful, otherwise it is not defined.  The check may also
+	succeed in case the referenced symbol is actually not a function.  There
+	is no need to specify header files to include.  This function sets the
+	``compiler``, ``define_name``, ``features``, ``fragment``, and ``msg``
+	parameters and then calls :py:func:`waflib.Tools.c_config.check` to
+	carry out the check.
+
+	:param function_name: the name of the function to check
+	:type function_name: string
+	"""
+	kw = check_func(function_name, **kw)
+	kw['features'] = 'cxx cxxprogram'
+	return self.check_cxx(*k, **kw)
+
+@conf
+def check_c_func(self, function_name, *k, **kw):
+	"""
+	Checks whether the library function specified by ``function_name``
+	exists.  This check is similar to the Autoconf AC_CHECK_FUNCS() macro.
+	Compiles and links a test program referencing the ``function_name``
+	symbol via a function call using the C compiler.  Defines
+	``HAVE_FUNCTION_NAME`` to 1 in the configuration header if the check
+	was successful, otherwise it is not defined.  The check may also
+	succeed in case the referenced symbol is actually not a function.  There
+	is no need to specify header files to include.  This function sets the
+	``compiler``, ``define_name``, ``features``, ``fragment``, and ``msg``
+	parameters and then calls :py:func:`waflib.Tools.c_config.check` to
+	carry out the check.
+
+	:param function_name: the name of the function to check
+	:type function_name: string
+	"""
+	kw = check_func(function_name, **kw)
+	kw['features'] = 'c cprogram'
+	return self.check_cc(*k, **kw)
+
 @conf
 def set_define_comment(self, key, comment):
 	"""