+def check_cc(env, cc, expr, cpp_opt = '-E'):
+ # Invoke C-preprocessor to determine whether the specified expression is
+ # true or not.
+
+ sys.stdout.write('Checking for %s ... ' % cc)
+
+ source = tempfile.NamedTemporaryFile(suffix='.c', delete=False)
+ source.write('#if !(%s)\n#error\n#endif\n' % expr)
+ source.close()
+
+ # sys.stderr.write('%r %s %s\n' % (env['CC'], cpp_opt, source.name));
+
+ pipe = SCons.Action._subproc(env, env.Split(env['CC']) + [cpp_opt, source.name],
+ stdin = 'devnull',
+ stderr = 'devnull',
+ stdout = 'devnull')
+ result = pipe.wait() == 0
+
+ os.unlink(source.name)
+
+ sys.stdout.write(' %s\n' % ['no', 'yes'][int(bool(result))])
+ return result
+
+def check_header(env, header):
+ '''Check if the header exist'''
+
+ conf = SCons.Script.Configure(env)
+ have_header = False
+
+ if conf.CheckHeader(header):
+ have_header = True
+
+ env = conf.Finish()
+ return have_header
+
+def check_functions(env, functions):
+ '''Check if all of the functions exist'''
+
+ conf = SCons.Script.Configure(env)
+ have_functions = True
+
+ for function in functions:
+ if not conf.CheckFunc(function):
+ have_functions = False
+
+ env = conf.Finish()
+ return have_functions
+
+def check_prog(env, prog):
+ """Check whether this program exists."""
+
+ sys.stdout.write('Checking for %s ... ' % prog)
+
+ result = env.Detect(prog)
+
+ sys.stdout.write(' %s\n' % ['no', 'yes'][int(bool(result))])
+ return result
+
+