bpo-36142: Rework error reporting in pymain_main() (GH-12113)

Add a new _Py_INIT_EXIT() macro to be able to exit Python with an
exitcode using _PyInitError API. Rewrite function calls by
pymain_main() to use _PyInitError.

Changes:

* Remove _PyMain.err and _PyMain.status field
* Add _Py_INIT_EXIT() macro and _PyInitError.exitcode field.
* Rename _Py_FatalInitError() to _Py_ExitInitError().

Include/cpython/coreconfig.h

@@ -11,6 +11,7 @@ typedef struct {
     const char *prefix;
     const char *msg;
     int user_err;
+    int exitcode;
 } _PyInitError;
 
 /* Almost all errors causing Python initialization to fail */
@@ -22,16 +23,18 @@ typedef struct {
 #endif
 
 #define _Py_INIT_OK() \
-    (_PyInitError){.prefix = NULL, .msg = NULL, .user_err = 0}
+    (_PyInitError){.prefix = NULL, .msg = NULL, .user_err = 0, .exitcode = -1}
 #define _Py_INIT_ERR(MSG) \
-    (_PyInitError){.prefix = _Py_INIT_GET_FUNC(), .msg = (MSG), .user_err = 0}
+    (_PyInitError){.prefix = _Py_INIT_GET_FUNC(), .msg = (MSG), .user_err = 0, .exitcode = -1}
 /* Error that can be fixed by the user like invalid input parameter.
    Don't abort() the process on such error. */
 #define _Py_INIT_USER_ERR(MSG) \
-    (_PyInitError){.prefix = _Py_INIT_GET_FUNC(), .msg = (MSG), .user_err = 1}
+    (_PyInitError){.prefix = _Py_INIT_GET_FUNC(), .msg = (MSG), .user_err = 1, .exitcode = -1}
 #define _Py_INIT_NO_MEMORY() _Py_INIT_USER_ERR("memory allocation failed")
+#define _Py_INIT_EXIT(EXITCODE) \
+    (_PyInitError){.prefix = NULL, .msg = NULL, .user_err = 0, .exitcode = (EXITCODE)}
 #define _Py_INIT_FAILED(err) \
-    (err.msg != NULL)
+    (err.msg != NULL || err.exitcode != -1)
 
 /* _PyCoreConfig */
 

Include/cpython/pylifecycle.h

@@ -39,7 +39,7 @@ PyAPI_FUNC(_PyInitError) _Py_InitializeMainInterpreter(
 
 PyAPI_FUNC(_PyInitError) _Py_InitializeFromConfig(
     const _PyCoreConfig *config);
-PyAPI_FUNC(void) _Py_NO_RETURN _Py_FatalInitError(_PyInitError err);
+PyAPI_FUNC(void) _Py_NO_RETURN _Py_ExitInitError(_PyInitError err);
 
 /* Py_PyAtExit is for the atexit module, Py_AtExit is for low-level
  * exit functions.

Programs/_freeze_importlib.c

@@ -89,7 +89,7 @@ main(int argc, char *argv[])
     /* No need to call _PyCoreConfig_Clear() since we didn't allocate any
        memory: program_name is a constant string. */
     if (_Py_INIT_FAILED(err)) {
-        _Py_FatalInitError(err);
+        _Py_ExitInitError(err);
     }
 
     sprintf(buf, "<frozen %s>", name);

Programs/_testembed.c

@@ -553,7 +553,7 @@ static int test_init_from_config(void)
     _PyInitError err = _Py_InitializeFromConfig(&config);
     /* Don't call _PyCoreConfig_Clear() since all strings are static */
     if (_Py_INIT_FAILED(err)) {
-        _Py_FatalInitError(err);
+        _Py_ExitInitError(err);
     }
     dump_config();
     Py_Finalize();
@@ -618,7 +618,7 @@ static int test_init_isolated(void)
     test_init_env_putenvs();
     _PyInitError err = _Py_InitializeFromConfig(&config);
     if (_Py_INIT_FAILED(err)) {
-        _Py_FatalInitError(err);
+        _Py_ExitInitError(err);
     }
     dump_config();
     Py_Finalize();
@@ -635,7 +635,7 @@ static int test_init_dev_mode(void)
     config.program_name = L"./_testembed";
     _PyInitError err = _Py_InitializeFromConfig(&config);
     if (_Py_INIT_FAILED(err)) {
-        _Py_FatalInitError(err);
+        _Py_ExitInitError(err);
     }
     dump_config();
     Py_Finalize();

Python/frozenmain.c

@@ -86,7 +86,7 @@ Py_FrozenMain(int argc, char **argv)
     /* No need to call _PyCoreConfig_Clear() since we didn't allocate any
        memory: program_name is a constant string. */
     if (_Py_INIT_FAILED(err)) {
-        _Py_FatalInitError(err);
+        _Py_ExitInitError(err);
     }
 
 #ifdef MS_WINDOWS

Python/pathconfig.c

@@ -408,7 +408,7 @@ pathconfig_global_init(void)
 
 error:
     _PyCoreConfig_Clear(&config);
-    _Py_FatalInitError(err);
+    _Py_ExitInitError(err);
 }
 
 

Python/pylifecycle.c

@@ -960,7 +960,7 @@ Py_InitializeEx(int install_sigs)
     _PyCoreConfig_Clear(&config);
 
     if (_Py_INIT_FAILED(err)) {
-        _Py_FatalInitError(err);
+        _Py_ExitInitError(err);
     }
 }
 
@@ -1432,7 +1432,7 @@ Py_NewInterpreter(void)
     PyThreadState *tstate;
     _PyInitError err = new_interpreter(&tstate);
     if (_Py_INIT_FAILED(err)) {
-        _Py_FatalInitError(err);
+        _Py_ExitInitError(err);
     }
     return tstate;
 
@@ -2073,12 +2073,17 @@ Py_FatalError(const char *msg)
 }
 
 void _Py_NO_RETURN
-_Py_FatalInitError(_PyInitError err)
+_Py_ExitInitError(_PyInitError err)
 {
-    /* On "user" error: exit with status 1.
-       For all other errors, call abort(). */
-    int status = err.user_err ? 1 : -1;
-    fatal_error(err.prefix, err.msg, status);
+    if (err.exitcode >= 0) {
+        exit(err.exitcode);
+    }
+    else {
+        /* On "user" error: exit with status 1.
+           For all other errors, call abort(). */
+        int status = err.user_err ? 1 : -1;
+        fatal_error(err.prefix, err.msg, status);
+    }
 }
 
 /* Clean up and exit */