bpo-40910: Export Py_GetArgcArgv() function (GH-20721)

Export explicitly the Py_GetArgcArgv() function to the C API and
document the function. Previously, it was exported implicitly which
no longer works since Python is built with -fvisibility=hidden.

* Add PyConfig._orig_argv member.
* Py_InitializeFromConfig() no longer calls _PyConfig_Write() twice.
* PyConfig_Read() no longer initializes Py_GetArgcArgv(): it is now
  _PyConfig_Write() responsibility.
* _PyConfig_Write() result type becomes PyStatus instead of void.
* Write an unit test on Py_GetArgcArgv().

1 files changed, 9 insertions, 5 deletions

diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index d730a98d3e..f2f7d585c8 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -460,7 +460,10 @@ pyinit_core_reconfigure(_PyRuntimeState *runtime,
         return _PyStatus_ERR("can't make main interpreter");
     }
 
-    _PyConfig_Write(config, runtime);
+    status = _PyConfig_Write(config, runtime);
+    if (_PyStatus_EXCEPTION(status)) {
+        return status;
+    }
 
     status = _PyInterpreterState_SetConfig(interp, config);
     if (_PyStatus_EXCEPTION(status)) {
@@ -486,7 +489,10 @@ pycore_init_runtime(_PyRuntimeState *runtime,
         return _PyStatus_ERR("main interpreter already initialized");
     }
 
-    _PyConfig_Write(config, runtime);
+    PyStatus status = _PyConfig_Write(config, runtime);
+    if (_PyStatus_EXCEPTION(status)) {
+        return status;
+    }
 
     /* Py_Finalize leaves _Py_Finalizing set in order to help daemon
      * threads behave a little more gracefully at interpreter shutdown.
@@ -499,7 +505,7 @@ pycore_init_runtime(_PyRuntimeState *runtime,
      */
     _PyRuntimeState_SetFinalizing(runtime, NULL);
 
-    PyStatus status = _Py_HashRandomization_Init(config);
+    status = _Py_HashRandomization_Init(config);
     if (_PyStatus_EXCEPTION(status)) {
         return status;
     }
@@ -746,8 +752,6 @@ pyinit_config(_PyRuntimeState *runtime,
               PyThreadState **tstate_p,
               const PyConfig *config)
 {
-    _PyConfig_Write(config, runtime);
-
     PyStatus status = pycore_init_runtime(runtime, config);
     if (_PyStatus_EXCEPTION(status)) {
         return status;