Add SCons-based build system.

config/python.py

@@ -0,0 +1,98 @@
+#
+# Copyright (c) 2016 Stefan Seefeld
+# All rights reserved.
+#
+# Distributed under the Boost Software License, Version 1.0.
+# (See accompanying file LICENSE_1_0.txt or copy at
+# http://www.boost.org/LICENSE_1_0.txt)
+
+from . import ui
+
+def add_options(vars):
+
+    ui.add_option('--python', help='the python executable')
+
+
+def check(context):
+
+    python_source_file = r"""
+// If defined, enforces linking againg PythonXXd.lib, which
+// is usually not included in Python environments.
+#undef _DEBUG
+#include "Python.h"
+int main()
+{
+  Py_Initialize();
+  Py_Finalize();
+  return 0;
+}
+"""
+
+    import platform
+    import subprocess
+    import re, os
+
+    def check_python(cmd):
+        return subprocess.check_output([python, '-c', cmd]).strip()
+
+    def check_sysconfig(cmd):
+        r = check_python('import distutils.sysconfig as c; print(c.%s)'%cmd)
+        return r if r != 'None' else ''
+
+    context.Message('Checking for Python...')
+    python = context.env.GetOption('python') or 'python'
+    context.env['PYTHON'] = python
+    incpath = check_sysconfig('get_python_inc()')
+    context.env.AppendUnique(CPPPATH=[incpath])
+    if platform.system() == 'Windows':
+        version = check_python('import sys; print("%d%d"%sys.version_info[0:2])')
+        prefix = check_python('import sys; print(sys.prefix)')
+        libfile = os.path.join(prefix, 'libs', 'python%s.lib'%version)
+        libpath = os.path.join(prefix, 'libs')
+        lib = 'python%s'%version
+        context.env.AppendUnique(LIBS=[lib])
+    else:
+        libpath = check_sysconfig('get_config_var("LIBDIR")')
+        libfile = check_sysconfig('get_config_var("LIBRARY")')
+        match = re.search('(python.*)\.(a|so|dylib)', libfile)
+        lib = None
+        if match:
+            lib = match.group(1)
+            context.env.AppendUnique(PYTHONLIBS=[lib])
+            if match.group(2) == 'a':
+                flags = check_sysconfig('get_config_var("LINKFORSHARED")')
+                if flags is not None:
+                    context.env.AppendUnique(LINKFLAGS=flags.split())
+    context.env.AppendUnique(LIBPATH=[libpath])
+    oldlibs = context.AppendLIBS([lib])
+    flags = check_sysconfig('get_config_var("MODLIBS")')
+    flags += ' ' + check_sysconfig('get_config_var("SHLIBS")')
+    flags = [f[2:] for f in flags.strip().split() if f.startswith('-l')]
+    if flags:
+        context.AppendLIBS([flags])
+    result = context.TryLink(python_source_file,'.cpp')
+    if not result and context.env['PLATFORM'] == 'darwin':
+        # Sometimes we need some extra stuff on Mac OS
+        frameworkDir = libpath # search up the libDir tree for the proper home for frameworks
+        while frameworkDir and frameworkDir != "/":
+            frameworkDir, d2 = os.path.split(frameworkDir)
+            if d2 == "Python.framework":
+                if not "Python" in os.listdir(os.path.join(frameworkDir, d2)):
+                    context.Result(0)
+                    print((
+                        "Expected to find Python in framework directory %s, but it isn't there"
+                        % frameworkDir))
+                    return False
+                break
+        context.env.AppendUnique(LINKFLAGS="-F%s" % frameworkDir)
+        result = context.TryLink(python_source_file,'.cpp')
+    if not result:
+        context.Result(0)
+        print("Cannot link program with Python.")
+        return False
+    if context.env['PLATFORM'] == 'darwin':
+        context.env['LDMODULESUFFIX'] = '.so'
+    context.Result(1)
+    context.SetLIBS(oldlibs)
+    context.env.AppendUnique(PYTHONLIBS=[lib] + flags)
+    return True