bpo-32030: Split Py_Main() into subfunctions (#4399)

* Don't use "Python runtime" anymore to parse command line options or
  to get environment variables: pymain_init() is now a strict
  separation.
* Use an error message rather than "crashing" directly with
  Py_FatalError(). Limit the number of calls to Py_FatalError(). It
  prepares the code to handle errors more nicely later.
* Warnings options (-W, PYTHONWARNINGS) and "XOptions" (-X) are now
  only added to the sys module once Python core is properly
  initialized.
* _PyMain is now the well identified owner of some important strings
  like: warnings options, XOptions, and the "program name". The
  program name string is now properly freed at exit.
  pymain_free() is now responsible to free the "command" string.
* Rename most methods in Modules/main.c to use a "pymain_" prefix to
  avoid conflits and ease debug.
* Replace _Py_CommandLineDetails_INIT with memset(0)
* Reorder a lot of code to fix the initialization ordering. For
  example, initializing standard streams now comes before parsing
  PYTHONWARNINGS.
* Py_Main() now handles errors when adding warnings options and
  XOptions.
* Add _PyMem_GetDefaultRawAllocator() private function.
* Cleanup _PyMem_Initialize(): remove useless global constants: move
  them into _PyMem_Initialize().
* Call _PyRuntime_Initialize() as soon as possible:
  _PyRuntime_Initialize() now returns an error message on failure.
* Add _PyInitError structure and following macros:

  * _Py_INIT_OK()
  * _Py_INIT_ERR(msg)
  * _Py_INIT_USER_ERR(msg): "user" error, don't abort() in that case
  * _Py_INIT_FAILED(err)

1 files changed, 7 insertions, 1 deletions

diff --git a/Include/internal/pystate.h b/Include/internal/pystate.h
index 210917b..516f829 100644
--- a/Include/internal/pystate.h
+++ b/Include/internal/pystate.h
@@ -74,10 +74,16 @@ typedef struct pyruntimestate {
     // XXX Consolidate globals found via the check-c-globals script.
 } _PyRuntimeState;
 
+#define _PyRuntimeState_INIT {.initialized = 0, .core_initialized = 0}
+
 PyAPI_DATA(_PyRuntimeState) _PyRuntime;
-PyAPI_FUNC(void) _PyRuntimeState_Init(_PyRuntimeState *);
+PyAPI_FUNC(_PyInitError) _PyRuntimeState_Init(_PyRuntimeState *);
 PyAPI_FUNC(void) _PyRuntimeState_Fini(_PyRuntimeState *);
 
+/* Initialize _PyRuntimeState.
+   Return NULL on success, or return an error message on failure. */
+PyAPI_FUNC(_PyInitError) _PyRuntime_Initialize(void);
+
 #define _Py_CURRENTLY_FINALIZING(tstate) \
     (_PyRuntime.finalizing == tstate)