1 files changed, 72 insertions, 3 deletions

diff --git a/Lib/sysconfig.py b/Lib/sysconfig.py
index d74ca391c6..aa69351bf0 100644
--- a/Lib/sysconfig.py
+++ b/Lib/sysconfig.py
@@ -278,9 +278,10 @@ def _get_makefile_filename():
         return os.path.join(_PROJECT_BASE, "Makefile")
     return os.path.join(get_path('platstdlib'), "config", "Makefile")
 
-
-def _init_posix(vars):
-    """Initialize the module as appropriate for POSIX systems."""
+def _generate_posix_vars():
+    """Generate the Python module containing build-time variables."""
+    import pprint
+    vars = {}
     # load the installed Makefile:
     makefile = _get_makefile_filename()
     try:
@@ -308,6 +309,49 @@ def _init_posix(vars):
     if _PYTHON_BUILD:
         vars['LDSHARED'] = vars['BLDSHARED']
 
+    # There's a chicken-and-egg situation on OS X with regards to the
+    # _sysconfigdata module after the changes introduced by #15298:
+    # get_config_vars() is called by get_platform() as part of the
+    # `make pybuilddir.txt` target -- which is a precursor to the
+    # _sysconfigdata.py module being constructed.  Unfortunately,
+    # get_config_vars() eventually calls _init_posix(), which attempts
+    # to import _sysconfigdata, which we won't have built yet.  In order
+    # for _init_posix() to work, if we're on Darwin, just mock up the
+    # _sysconfigdata module manually and populate it with the build vars.
+    # This is more than sufficient for ensuring the subsequent call to
+    # get_platform() succeeds.
+    name = '_sysconfigdata'
+    if 'darwin' in sys.platform:
+        import imp
+        module = imp.new_module(name)
+        module.build_time_vars = vars
+        sys.modules[name] = module
+
+    pybuilddir = 'build/lib.%s-%s' % (get_platform(), sys.version[:3])
+    if hasattr(sys, "gettotalrefcount"):
+        pybuilddir += '-pydebug'
+    try:
+        os.makedirs(pybuilddir)
+    except OSError:
+        pass
+    destfile = os.path.join(pybuilddir, name + '.py')
+
+    with open(destfile, 'wb') as f:
+        f.write('# system configuration generated and used by'
+                ' the sysconfig module\n')
+        f.write('build_time_vars = ')
+        pprint.pprint(vars, stream=f)
+
+    # Create file used for sys.path fixup -- see Modules/getpath.c
+    with open('pybuilddir.txt', 'w') as f:
+        f.write(pybuilddir)
+
+def _init_posix(vars):
+    """Initialize the module as appropriate for POSIX systems."""
+    # _sysconfigdata is generated at build time, see _generate_posix_vars()
+    from _sysconfigdata import build_time_vars
+    vars.update(build_time_vars)
+
 def _init_non_posix(vars):
     """Initialize the module as appropriate for NT"""
     # set basic install directories
@@ -565,3 +609,28 @@ def get_platform():
 
 def get_python_version():
     return _PY_VERSION_SHORT
+
+
+def _print_dict(title, data):
+    for index, (key, value) in enumerate(sorted(data.items())):
+        if index == 0:
+            print '%s: ' % (title)
+        print '\t%s = "%s"' % (key, value)
+
+
+def _main():
+    """Display all information sysconfig detains."""
+    if '--generate-posix-vars' in sys.argv:
+        _generate_posix_vars()
+        return
+    print 'Platform: "%s"' % get_platform()
+    print 'Python version: "%s"' % get_python_version()
+    print 'Current installation scheme: "%s"' % _get_default_scheme()
+    print
+    _print_dict('Paths', get_paths())
+    print
+    _print_dict('Variables', get_config_vars())
+
+
+if __name__ == '__main__':
+    _main()