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, 25 insertions, 4 deletions

diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index eed583a..ea0d7a5 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -735,7 +735,12 @@ _Py_PreInitializeFromPyArgv(const PyPreConfig *src_config, const _PyArgv *args)
     runtime->preinitializing = 1;
 
     PyPreConfig config;
-    _PyPreConfig_InitFromPreConfig(&config, src_config);
+    config.struct_size = sizeof(PyPreConfig);
+
+    status = _PyPreConfig_InitFromPreConfig(&config, src_config);
+    if (_PyStatus_EXCEPTION(status)) {
+        return status;
+    }
 
     status = _PyPreConfig_Read(&config, args);
     if (_PyStatus_EXCEPTION(status)) {
@@ -794,7 +799,12 @@ _Py_PreInitializeFromConfig(const PyConfig *config,
     }
 
     PyPreConfig preconfig;
-    _PyPreConfig_InitFromConfig(&preconfig, config);
+    preconfig.struct_size = sizeof(PyPreConfig);
+
+    status = _PyPreConfig_InitFromConfig(&preconfig, config);
+    if (_PyStatus_EXCEPTION(status)) {
+        return status;
+    }
 
     if (!config->parse_argv) {
         return Py_PreInitialize(&preconfig);
@@ -842,7 +852,12 @@ pyinit_core(_PyRuntimeState *runtime,
     }
 
     PyConfig config;
-    _PyConfig_InitCompatConfig(&config);
+    config.struct_size = sizeof(PyConfig);
+
+    status = _PyConfig_InitCompatConfig(&config);
+    if (_PyStatus_EXCEPTION(status)) {
+        goto done;
+    }
 
     status = _PyConfig_Copy(&config, src_config);
     if (_PyStatus_EXCEPTION(status)) {
@@ -1064,7 +1079,13 @@ Py_InitializeEx(int install_sigs)
     }
 
     PyConfig config;
-    _PyConfig_InitCompatConfig(&config);
+    config.struct_size = sizeof(PyConfig);
+
+    status = _PyConfig_InitCompatConfig(&config);
+    if (_PyStatus_EXCEPTION(status)) {
+        Py_ExitStatusException(status);
+    }
+
     config.install_signal_handlers = install_sigs;
 
     status = Py_InitializeFromConfig(&config);