bpo-38304: Add PyConfig.struct_size (GH-16451)

Add a new struct_size field to PyPreConfig and PyConfig structures to
allow to modify these structures in the future without breaking the
backward compatibility.

* Replace private _config_version field with public struct_size field
  in PyPreConfig and PyConfig.
* Public PyPreConfig_InitIsolatedConfig() and
  PyPreConfig_InitPythonConfig()
  return type becomes PyStatus, instead of void.
* Internal _PyConfig_InitCompatConfig(),
  _PyPreConfig_InitCompatConfig(), _PyPreConfig_InitFromConfig(),
  _PyPreConfig_InitFromPreConfig() return type becomes PyStatus,
  instead of void.
* Remove _Py_CONFIG_VERSION
* Update the Initialization Configuration documentation.

1 files changed, 6 insertions, 1 deletions

diff --git a/Python/pathconfig.c b/Python/pathconfig.c
index 8126145..6886ab7 100644
--- a/Python/pathconfig.c
+++ b/Python/pathconfig.c
@@ -434,7 +434,12 @@ pathconfig_global_read(_PyPathConfig *pathconfig)
 {
     PyStatus status;
     PyConfig config;
-    _PyConfig_InitCompatConfig(&config);
+    config.struct_size = sizeof(PyConfig);
+
+    status = _PyConfig_InitCompatConfig(&config);
+    if (_PyStatus_EXCEPTION(status)) {
+        goto done;
+    }
 
     /* Call _PyConfig_InitPathConfig() */
     status = PyConfig_Read(&config);