bpo-36763: Implement the PEP 587 (GH-13592)

* Add a whole new documentation page:
  "Python Initialization Configuration"
* PyWideStringList_Append() return type is now PyStatus,
  instead of int
* PyInterpreterState_New() now calls PyConfig_Clear() if
  PyConfig_InitPythonConfig() fails.
* Rename files:

  * Python/coreconfig.c => Python/initconfig.c
  * Include/cpython/coreconfig.h => Include/cpython/initconfig.h
  * Include/internal/: pycore_coreconfig.h => pycore_initconfig.h

* Rename structures

  * _PyCoreConfig => PyConfig
  * _PyPreConfig => PyPreConfig
  * _PyInitError => PyStatus
  * _PyWstrList => PyWideStringList

* Rename PyConfig fields:

  * use_module_search_paths => module_search_paths_set
  * module_search_path_env => pythonpath_env

* Rename PyStatus field: _func => func
* PyInterpreterState: rename core_config field to config
* Rename macros and functions:

  * _PyCoreConfig_SetArgv() => PyConfig_SetBytesArgv()
  * _PyCoreConfig_SetWideArgv() => PyConfig_SetArgv()
  * _PyCoreConfig_DecodeLocale() => PyConfig_SetBytesString()
  * _PyInitError_Failed() => PyStatus_Exception()
  * _Py_INIT_ERROR_TYPE_xxx enums => _PyStatus_TYPE_xxx
  * _Py_UnixMain() => Py_BytesMain()
  * _Py_ExitInitError() => Py_ExitStatusException()
  * _Py_PreInitializeFromArgs() => Py_PreInitializeFromBytesArgs()
  * _Py_PreInitializeFromWideArgs() => Py_PreInitializeFromArgs()
  * _Py_PreInitialize() => Py_PreInitialize()
  * _Py_RunMain() => Py_RunMain()
  * _Py_InitializeFromConfig() => Py_InitializeFromConfig()
  * _Py_INIT_XXX() => _PyStatus_XXX()
  * _Py_INIT_FAILED() => _PyStatus_EXCEPTION()

* Rename 'err' PyStatus variables to 'status'
* Convert RUN_CODE() macro to config_run_code() static inline function
* Remove functions:

  * _Py_InitializeFromArgs()
  * _Py_InitializeFromWideArgs()
  * _PyInterpreterState_GetCoreConfig()

3 files changed, 82 insertions, 91 deletions

diff --git a/Include/cpython/coreconfig.h b/Include/cpython/initconfig.h
index ef5fde2..a98b91a 100644
--- a/Include/cpython/coreconfig.h
+++ b/Include/cpython/initconfig.h
@@ -5,56 +5,49 @@
 extern "C" {
 #endif
 
-/* --- _PyInitError ----------------------------------------------- */
+/* --- PyStatus ----------------------------------------------- */
 
 typedef struct {
     enum {
-        _Py_INIT_ERR_TYPE_OK=0,
-        _Py_INIT_ERR_TYPE_ERROR=1,
-        _Py_INIT_ERR_TYPE_EXIT=2
+        _PyStatus_TYPE_OK=0,
+        _PyStatus_TYPE_ERROR=1,
+        _PyStatus_TYPE_EXIT=2
     } _type;
-    const char *_func;
+    const char *func;
     const char *err_msg;
     int exitcode;
-} _PyInitError;
+} PyStatus;
 
-PyAPI_FUNC(_PyInitError) _PyInitError_Ok(void);
-PyAPI_FUNC(_PyInitError) _PyInitError_Error(const char *err_msg);
-PyAPI_FUNC(_PyInitError) _PyInitError_NoMemory(void);
-PyAPI_FUNC(_PyInitError) _PyInitError_Exit(int exitcode);
-PyAPI_FUNC(int) _PyInitError_IsError(_PyInitError err);
-PyAPI_FUNC(int) _PyInitError_IsExit(_PyInitError err);
-PyAPI_FUNC(int) _PyInitError_Failed(_PyInitError err);
+PyAPI_FUNC(PyStatus) PyStatus_Ok(void);
+PyAPI_FUNC(PyStatus) PyStatus_Error(const char *err_msg);
+PyAPI_FUNC(PyStatus) PyStatus_NoMemory(void);
+PyAPI_FUNC(PyStatus) PyStatus_Exit(int exitcode);
+PyAPI_FUNC(int) PyStatus_IsError(PyStatus err);
+PyAPI_FUNC(int) PyStatus_IsExit(PyStatus err);
+PyAPI_FUNC(int) PyStatus_Exception(PyStatus err);
 
-/* --- _PyWstrList ------------------------------------------------ */
+/* --- PyWideStringList ------------------------------------------------ */
 
 typedef struct {
     /* If length is greater than zero, items must be non-NULL
        and all items strings must be non-NULL */
     Py_ssize_t length;
     wchar_t **items;
-} _PyWstrList;
+} PyWideStringList;
 
+PyAPI_FUNC(PyStatus) PyWideStringList_Append(PyWideStringList *list,
+    const wchar_t *item);
 
-/* --- _PyPreConfig ----------------------------------------------- */
-
-#define _Py_CONFIG_VERSION 1
-
-typedef enum {
-    /* Py_Initialize() API: backward compatibility with Python 3.6 and 3.7 */
-    _PyConfig_INIT_COMPAT = 1,
-    _PyConfig_INIT_PYTHON = 2,
-    _PyConfig_INIT_ISOLATED = 3
-} _PyConfigInitEnum;
 
+/* --- PyPreConfig ----------------------------------------------- */
 
 typedef struct {
     int _config_version;  /* Internal configuration version,
                              used for ABI compatibility */
     int _config_init;     /* _PyConfigInitEnum value */
 
-    /* Parse _Py_PreInitializeFromArgs() arguments?
-       See _PyCoreConfig.parse_argv */
+    /* Parse Py_PreInitializeFromBytesArgs() arguments?
+       See PyConfig.parse_argv */
     int parse_argv;
 
     /* If greater than 0, enable isolated mode: sys.path contains
@@ -124,22 +117,22 @@ typedef struct {
     /* Memory allocator: PYTHONMALLOC env var.
        See PyMemAllocatorName for valid values. */
     int allocator;
-} _PyPreConfig;
+} PyPreConfig;
 
-PyAPI_FUNC(void) _PyPreConfig_InitPythonConfig(_PyPreConfig *config);
-PyAPI_FUNC(void) _PyPreConfig_InitIsolatedConfig(_PyPreConfig *config);
+PyAPI_FUNC(void) PyPreConfig_InitPythonConfig(PyPreConfig *config);
+PyAPI_FUNC(void) PyPreConfig_InitIsolatedConfig(PyPreConfig *config);
 
 
-/* --- _PyCoreConfig ---------------------------------------------- */
+/* --- PyConfig ---------------------------------------------- */
 
 typedef struct {
     int _config_version;  /* Internal configuration version,
                              used for ABI compatibility */
     int _config_init;     /* _PyConfigInitEnum value */
 
-    int isolated;         /* Isolated mode? see _PyPreConfig.isolated */
-    int use_environment;  /* Use environment variables? see _PyPreConfig.use_environment */
-    int dev_mode;         /* Development mode? See _PyPreConfig.dev_mode */
+    int isolated;         /* Isolated mode? see PyPreConfig.isolated */
+    int use_environment;  /* Use environment variables? see PyPreConfig.use_environment */
+    int dev_mode;         /* Development mode? See PyPreConfig.dev_mode */
 
     /* Install signal handlers? Yes by default. */
     int install_signal_handlers;
@@ -207,7 +200,7 @@ typedef struct {
 
        If argv is empty, an empty string is added to ensure that sys.argv
        always exists and is never empty. */
-    _PyWstrList argv;
+    PyWideStringList argv;
 
     /* Program name:
 
@@ -219,8 +212,8 @@ typedef struct {
        - Use "python" on Windows, or "python3 on other platforms. */
     wchar_t *program_name;
 
-    _PyWstrList xoptions;     /* Command line -X options */
-    _PyWstrList warnoptions;  /* Warnings options */
+    PyWideStringList xoptions;     /* Command line -X options */
+    PyWideStringList warnoptions;  /* Warnings options */
 
     /* If equal to zero, disable the import of the module site and the
        site-dependent manipulations of sys.path that it entails. Also disable
@@ -347,17 +340,37 @@ typedef struct {
     int legacy_windows_stdio;
 #endif
 
+    /* Value of the --check-hash-based-pycs command line option:
+
+       - "default" means the 'check_source' flag in hash-based pycs
+         determines invalidation
+       - "always" causes the interpreter to hash the source file for
+         invalidation regardless of value of 'check_source' bit
+       - "never" causes the interpreter to always assume hash-based pycs are
+         valid
+
+       The default value is "default".
+
+       See PEP 552 "Deterministic pycs" for more details. */
+    wchar_t *check_hash_pycs_mode;
+
     /* --- Path configuration inputs ------------ */
 
-    wchar_t *module_search_path_env; /* PYTHONPATH environment variable */
+    /* If greater than 0, suppress _PyPathConfig_Calculate() warnings on Unix.
+       The parameter has no effect on Windows.
+
+       If set to -1 (default), inherit !Py_FrozenFlag value. */
+    int pathconfig_warnings;
+
+    wchar_t *pythonpath_env; /* PYTHONPATH environment variable */
     wchar_t *home;          /* PYTHONHOME environment variable,
                                see also Py_SetPythonHome(). */
 
     /* --- Path configuration outputs ----------- */
 
-    int use_module_search_paths;  /* If non-zero, use module_search_paths */
-    _PyWstrList module_search_paths;  /* sys.path paths. Computed if
-                                       use_module_search_paths is equal
+    int module_search_paths_set;  /* If non-zero, use module_search_paths */
+    PyWideStringList module_search_paths;  /* sys.path paths. Computed if
+                                       module_search_paths_set is equal
                                        to zero. */
 
     wchar_t *executable;    /* sys.executable */
@@ -384,48 +397,28 @@ typedef struct {
        Needed by freeze_importlib. */
     int _install_importlib;
 
-    /* Value of the --check-hash-based-pycs command line option:
-
-       - "default" means the 'check_source' flag in hash-based pycs
-         determines invalidation
-       - "always" causes the interpreter to hash the source file for
-         invalidation regardless of value of 'check_source' bit
-       - "never" causes the interpreter to always assume hash-based pycs are
-         valid
-
-       The default value is "default".
-
-       See PEP 552 "Deterministic pycs" for more details. */
-    wchar_t *check_hash_pycs_mode;
-
-    /* If greater than 0, suppress _PyPathConfig_Calculate() warnings on Unix.
-       The parameter has no effect on Windows.
-
-       If set to -1 (default), inherit !Py_FrozenFlag value. */
-    int pathconfig_warnings;
-
     /* If equal to 0, stop Python initialization before the "main" phase */
     int _init_main;
 
-} _PyCoreConfig;
+} PyConfig;
 
-PyAPI_FUNC(_PyInitError) _PyCoreConfig_InitPythonConfig(_PyCoreConfig *config);
-PyAPI_FUNC(_PyInitError) _PyCoreConfig_InitIsolatedConfig(_PyCoreConfig *config);
-PyAPI_FUNC(void) _PyCoreConfig_Clear(_PyCoreConfig *);
-PyAPI_FUNC(_PyInitError) _PyCoreConfig_SetString(
-    _PyCoreConfig *config,
+PyAPI_FUNC(PyStatus) PyConfig_InitPythonConfig(PyConfig *config);
+PyAPI_FUNC(PyStatus) PyConfig_InitIsolatedConfig(PyConfig *config);
+PyAPI_FUNC(void) PyConfig_Clear(PyConfig *);
+PyAPI_FUNC(PyStatus) PyConfig_SetString(
+    PyConfig *config,
     wchar_t **config_str,
     const wchar_t *str);
-PyAPI_FUNC(_PyInitError) _PyCoreConfig_DecodeLocale(
-    _PyCoreConfig *config,
+PyAPI_FUNC(PyStatus) PyConfig_SetBytesString(
+    PyConfig *config,
     wchar_t **config_str,
     const char *str);
-PyAPI_FUNC(_PyInitError) _PyCoreConfig_Read(_PyCoreConfig *config);
-PyAPI_FUNC(_PyInitError) _PyCoreConfig_SetArgv(
-    _PyCoreConfig *config,
+PyAPI_FUNC(PyStatus) PyConfig_Read(PyConfig *config);
+PyAPI_FUNC(PyStatus) PyConfig_SetBytesArgv(
+    PyConfig *config,
     Py_ssize_t argc,
     char * const *argv);
-PyAPI_FUNC(_PyInitError) _PyCoreConfig_SetWideArgv(_PyCoreConfig *config,
+PyAPI_FUNC(PyStatus) PyConfig_SetArgv(PyConfig *config,
     Py_ssize_t argc,
     wchar_t * const *argv);
 
diff --git a/Include/cpython/pylifecycle.h b/Include/cpython/pylifecycle.h
index ba56664..2f3a0db 100644
--- a/Include/cpython/pylifecycle.h
+++ b/Include/cpython/pylifecycle.h
@@ -14,14 +14,14 @@ PyAPI_FUNC(int) Py_SetStandardStreamEncoding(const char *encoding,
 
 /* PEP 432 Multi-phase initialization API (Private while provisional!) */
 
-PyAPI_FUNC(_PyInitError) _Py_PreInitialize(
-    const _PyPreConfig *src_config);
-PyAPI_FUNC(_PyInitError) _Py_PreInitializeFromArgs(
-    const _PyPreConfig *src_config,
+PyAPI_FUNC(PyStatus) Py_PreInitialize(
+    const PyPreConfig *src_config);
+PyAPI_FUNC(PyStatus) Py_PreInitializeFromBytesArgs(
+    const PyPreConfig *src_config,
     Py_ssize_t argc,
     char **argv);
-PyAPI_FUNC(_PyInitError) _Py_PreInitializeFromWideArgs(
-    const _PyPreConfig *src_config,
+PyAPI_FUNC(PyStatus) Py_PreInitializeFromArgs(
+    const PyPreConfig *src_config,
     Py_ssize_t argc,
     wchar_t **argv);
 
@@ -30,22 +30,22 @@ PyAPI_FUNC(int) _Py_IsCoreInitialized(void);
 
 /* Initialization and finalization */
 
-PyAPI_FUNC(_PyInitError) _Py_InitializeFromConfig(
-    const _PyCoreConfig *config);
-PyAPI_FUNC(_PyInitError) _Py_InitializeFromArgs(
-    const _PyCoreConfig *config,
+PyAPI_FUNC(PyStatus) Py_InitializeFromConfig(
+    const PyConfig *config);
+PyAPI_FUNC(PyStatus) _Py_InitializeFromArgs(
+    const PyConfig *config,
     Py_ssize_t argc,
     char * const *argv);
-PyAPI_FUNC(_PyInitError) _Py_InitializeFromWideArgs(
-    const _PyCoreConfig *config,
+PyAPI_FUNC(PyStatus) _Py_InitializeFromWideArgs(
+    const PyConfig *config,
     Py_ssize_t argc,
     wchar_t * const *argv);
-PyAPI_FUNC(_PyInitError) _Py_InitializeMain(void);
+PyAPI_FUNC(PyStatus) _Py_InitializeMain(void);
 
-PyAPI_FUNC(int) _Py_RunMain(void);
+PyAPI_FUNC(int) Py_RunMain(void);
 
 
-PyAPI_FUNC(void) _Py_NO_RETURN _Py_ExitInitError(_PyInitError err);
+PyAPI_FUNC(void) _Py_NO_RETURN Py_ExitStatusException(PyStatus err);
 
 /* Py_PyAtExit is for the atexit module, Py_AtExit is for low-level
  * exit functions.
diff --git a/Include/cpython/pystate.h b/Include/cpython/pystate.h
index 94331f3..6b7663f 100644
--- a/Include/cpython/pystate.h
+++ b/Include/cpython/pystate.h
@@ -6,13 +6,11 @@
 extern "C" {
 #endif
 
-#include "cpython/coreconfig.h"
+#include "cpython/initconfig.h"
 
 PyAPI_FUNC(int) _PyInterpreterState_RequiresIDRef(PyInterpreterState *);
 PyAPI_FUNC(void) _PyInterpreterState_RequireIDRef(PyInterpreterState *, int);
 
-PyAPI_FUNC(_PyCoreConfig *) _PyInterpreterState_GetCoreConfig(PyInterpreterState *);
-
 PyAPI_FUNC(PyObject *) _PyInterpreterState_GetMainModule(PyInterpreterState *);
 
 /* State unique per thread */