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, 10 insertions, 15 deletions

diff --git a/Modules/main.c b/Modules/main.c
index ae99901f1d..5c7f7e4567 100644
--- a/Modules/main.c
+++ b/Modules/main.c
@@ -84,15 +84,15 @@ error:
 static PyObject*
 mainconfig_create_xoptions_dict(const _PyCoreConfig *config)
 {
-    int nxoption = config->nxoption;
-    wchar_t **xoptions = config->xoptions;
+    Py_ssize_t nxoption = config->xoptions.length;
+    wchar_t * const * xoptions = config->xoptions.items;
     PyObject *dict = PyDict_New();
     if (dict == NULL) {
         return NULL;
     }
 
-    for (int i=0; i < nxoption; i++) {
-        wchar_t *option = xoptions[i];
+    for (Py_ssize_t i=0; i < nxoption; i++) {
+        const wchar_t *option = xoptions[i];
         if (mainconfig_add_xoption(dict, option) < 0) {
             Py_DECREF(dict);
             return NULL;
@@ -243,22 +243,18 @@ _PyMainInterpreterConfig_Read(_PyMainInterpreterConfig *main_config,
             } \
         } \
     } while (0)
-#define COPY_WSTRLIST(ATTR, LEN, LIST) \
+#define COPY_WSTRLIST(ATTR, LIST) \
     do { \
         if (ATTR == NULL) { \
-            ATTR = _Py_wstrlist_as_pylist(LEN, LIST); \
+            ATTR = _PyWstrList_AsList(LIST); \
             if (ATTR == NULL) { \
                 return _Py_INIT_NO_MEMORY(); \
             } \
         } \
     } while (0)
 
-    COPY_WSTRLIST(main_config->warnoptions,
-                  config->nwarnoption, config->warnoptions);
-    if (config->argc >= 0) {
-        COPY_WSTRLIST(main_config->argv,
-                      config->argc, config->argv);
-    }
+    COPY_WSTRLIST(main_config->warnoptions, &config->warnoptions);
+    COPY_WSTRLIST(main_config->argv, &config->argv);
 
     if (config->_install_importlib) {
         COPY_WSTR(executable);
@@ -268,7 +264,7 @@ _PyMainInterpreterConfig_Read(_PyMainInterpreterConfig *main_config,
         COPY_WSTR(base_exec_prefix);
 
         COPY_WSTRLIST(main_config->module_search_path,
-                      config->nmodule_search_path, config->module_search_paths);
+                      &config->module_search_paths);
 
         if (config->pycache_prefix != NULL) {
             COPY_WSTR(pycache_prefix);
@@ -784,8 +780,7 @@ pymain_run_python(PyInterpreterState *interp, int *exitcode)
         }
     }
     else if (!config->preconfig.isolated) {
-        PyObject *path0 = _PyPathConfig_ComputeArgv0(config->argc,
-                                                     config->argv);
+        PyObject *path0 = _PyPathConfig_ComputeArgv0(&config->argv);
         if (path0 == NULL) {
             err = _Py_INIT_NO_MEMORY();
             goto done;