bpo-36301: Add _PyWstrList structure (GH-12343)

Replace messy _Py_wstrlist_xxx() functions with a new clean
_PyWstrList structure and new _PyWstrList_xxx() functions.

Changes:

* Add _PyCoreConfig.use_module_search_paths to decide if
  _PyCoreConfig.module_search_paths should be computed or not, to
  support empty search path list.
* _PyWstrList_Clear() sets length to 0 and items to NULL, whereas
  _Py_wstrlist_clear() only freed memory.
* _PyWstrList_Append() returns an int, whereas _Py_wstrlist_append()
  returned _PyInitError.
* _PyWstrList uses Py_ssize_t for the length, instead of int.
* Replace (int, wchar_t**) with _PyWstrList in:

  * _PyPreConfig
  * _PyCoreConfig
  * _PyPreCmdline
  * _PyCmdline

* Replace "int orig_argv; wchar_t **orig_argv;"
  with "_PyWstrList orig_argv".
* _PyCmdline and _PyPreCmdline now also copy wchar_argv.
* Rename _PyArgv_Decode() to _PyArgv_AsWstrList().
* PySys_SetArgvEx() now pass the fixed (argc, argv) to
  _PyPathConfig_ComputeArgv0() (don't pass negative argc or NULL
  argv).
* _PyOS_GetOpt() uses Py_ssize_t

1 files changed, 4 insertions, 4 deletions

diff --git a/Python/getopt.c b/Python/getopt.c
index 1dc8720..10bd1d4 100644
--- a/Python/getopt.c
+++ b/Python/getopt.c
@@ -37,9 +37,9 @@
 extern "C" {
 #endif
 
-int _PyOS_opterr = 1;          /* generate error messages */
-int _PyOS_optind = 1;          /* index into argv array   */
-wchar_t *_PyOS_optarg = NULL;     /* optional argument       */
+int _PyOS_opterr = 1;                 /* generate error messages */
+Py_ssize_t _PyOS_optind = 1;          /* index into argv array   */
+const wchar_t *_PyOS_optarg = NULL;   /* optional argument       */
 
 static wchar_t *opt_ptr = L"";
 
@@ -61,7 +61,7 @@ void _PyOS_ResetGetOpt(void)
     opt_ptr = L"";
 }
 
-int _PyOS_GetOpt(int argc, wchar_t **argv, int *longindex)
+int _PyOS_GetOpt(Py_ssize_t argc, wchar_t **argv, int *longindex)
 {
     wchar_t *ptr;
     wchar_t option;