bpo-36301: Add _Py_GetConfigsAsDict() function (GH-12540)

* Add _Py_GetConfigsAsDict() function to get all configurations as a
  dict.
* dump_config() of _testembed.c now dumps preconfig as a separated
  key: call _Py_GetConfigsAsDict().
* Make _PyMainInterpreterConfig_AsDict() private.

Include/cpython/coreconfig.h

@@ -400,8 +400,7 @@ typedef struct {
 
 /* --- Function used for testing ---------------------------------- */
 
-PyAPI_FUNC(PyObject *) _Py_GetGlobalVariablesAsDict(void);
-PyAPI_FUNC(PyObject *) _PyCoreConfig_AsDict(const _PyCoreConfig *config);
+PyAPI_FUNC(PyObject*) _Py_GetConfigsAsDict(void);
 
 #ifdef __cplusplus
 }

Include/cpython/pylifecycle.h

@@ -33,9 +33,6 @@ PyAPI_FUNC(void) _PyMainInterpreterConfig_Clear(_PyMainInterpreterConfig *);
 PyAPI_FUNC(int) _PyMainInterpreterConfig_Copy(
     _PyMainInterpreterConfig *config,
     const _PyMainInterpreterConfig *config2);
-/* Used by _testcapi.get_main_config() */
-PyAPI_FUNC(PyObject*) _PyMainInterpreterConfig_AsDict(
-    const _PyMainInterpreterConfig *config);
 
 PyAPI_FUNC(_PyInitError) _Py_InitializeMainInterpreter(
     PyInterpreterState *interp,

Include/internal/pycore_coreconfig.h

@@ -90,8 +90,7 @@ PyAPI_FUNC(void) _Py_get_env_flag(_PyPreConfig *config,
 PyAPI_FUNC(_PyInitError) _PyPreConfig_Read(_PyPreConfig *config,
     const _PyArgv *args,
     const _PyCoreConfig *coreconfig);
-PyAPI_FUNC(int) _PyPreConfig_AsDict(const _PyPreConfig *config,
-    PyObject *dict);
+PyAPI_FUNC(PyObject*) _PyPreConfig_AsDict(const _PyPreConfig *config);
 PyAPI_FUNC(_PyInitError) _PyPreConfig_ReadFromArgv(_PyPreConfig *config,
     const _PyArgv *args);
 PyAPI_FUNC(_PyInitError) _PyPreConfig_Write(_PyPreConfig *config);
@@ -121,6 +120,11 @@ PyAPI_FUNC(_PyInitError) _PyCoreConfig_ReadFromArgv(_PyCoreConfig *config,
     const _PyArgv *args);
 PyAPI_FUNC(_PyInitError) _PyCoreConfig_Write(const _PyCoreConfig *config);
 
+/* --- _PyMainInterpreterConfig ----------------------------------- */
+
+PyAPI_FUNC(PyObject*) _PyMainInterpreterConfig_AsDict(
+    const _PyMainInterpreterConfig *config);
+
 #ifdef __cplusplus
 }
 #endif

Lib/test/pythoninfo.py

@@ -598,18 +598,15 @@ def collect_get_config(info_add):
     # Dump global configuration variables, _PyCoreConfig
     # and _PyMainInterpreterConfig
     try:
-        from _testcapi import get_global_config, get_core_config, get_main_config
+        from _testcapi import get_configs
     except ImportError:
         return
 
-    for prefix, get_config_func in (
-        ('global_config', get_global_config),
-        ('core_config', get_core_config),
-        ('main_config', get_main_config),
-    ):
-        config = get_config_func()
+    all_configs = get_configs()
+    for config_type in sorted(all_configs):
+        config = all_configs[config_type]
         for key in sorted(config):
-            info_add('%s[%s]' % (prefix, key), repr(config[key]))
+            info_add('%s[%s]' % (config_type, key), repr(config[key]))
 
 
 def collect_subprocess(info_add):

Modules/_testcapimodule.c

@@ -4675,27 +4675,9 @@ decode_locale_ex(PyObject *self, PyObject *args)
 
 
 static PyObject *
-get_global_config(PyObject *self, PyObject *Py_UNUSED(args))
+get_configs(PyObject *self, PyObject *Py_UNUSED(args))
 {
-    return _Py_GetGlobalVariablesAsDict();
-}
-
-
-static PyObject *
-get_core_config(PyObject *self, PyObject *Py_UNUSED(args))
-{
-    PyInterpreterState *interp = _PyInterpreterState_Get();
-    const _PyCoreConfig *config = _PyInterpreterState_GetCoreConfig(interp);
-    return _PyCoreConfig_AsDict(config);
-}
-
-
-static PyObject *
-get_main_config(PyObject *self, PyObject *Py_UNUSED(args))
-{
-    PyInterpreterState *interp = _PyInterpreterState_Get();
-    const _PyMainInterpreterConfig *config = _PyInterpreterState_GetMainConfig(interp);
-    return _PyMainInterpreterConfig_AsDict(config);
+    return _Py_GetConfigsAsDict();
 }
 
 
@@ -4942,9 +4924,7 @@ static PyMethodDef TestMethods[] = {
     {"bad_get", (PyCFunction)(void(*)(void))bad_get, METH_FASTCALL},
     {"EncodeLocaleEx", encode_locale_ex, METH_VARARGS},
     {"DecodeLocaleEx", decode_locale_ex, METH_VARARGS},
-    {"get_global_config", get_global_config, METH_NOARGS},
-    {"get_core_config", get_core_config, METH_NOARGS},
-    {"get_main_config", get_main_config, METH_NOARGS},
+    {"get_configs", get_configs, METH_NOARGS},
 #ifdef Py_REF_DEBUG
     {"negative_refcount", negative_refcount, METH_NOARGS},
 #endif

Programs/_testembed.c

@@ -301,64 +301,29 @@ static int test_initialize_pymain(void)
 static int
 dump_config_impl(void)
 {
-    PyObject *config = NULL;
-    PyObject *dict = NULL;
-
-    config = PyDict_New();
+    PyObject *config = _Py_GetConfigsAsDict();
     if (config == NULL) {
-        goto error;
-    }
-
-    /* global config */
-    dict = _Py_GetGlobalVariablesAsDict();
-    if (dict == NULL) {
-        goto error;
-    }
-    if (PyDict_SetItemString(config, "global_config", dict) < 0) {
-        goto error;
-    }
-    Py_CLEAR(dict);
-
-    /* core config */
-    PyInterpreterState *interp = _PyInterpreterState_Get();
-    const _PyCoreConfig *core_config = _PyInterpreterState_GetCoreConfig(interp);
-    dict = _PyCoreConfig_AsDict(core_config);
-    if (dict == NULL) {
-        goto error;
-    }
-    if (PyDict_SetItemString(config, "core_config", dict) < 0) {
-        goto error;
-    }
-    Py_CLEAR(dict);
-
-    /* main config */
-    const _PyMainInterpreterConfig *main_config = _PyInterpreterState_GetMainConfig(interp);
-    dict = _PyMainInterpreterConfig_AsDict(main_config);
-    if (dict == NULL) {
-        goto error;
-    }
-    if (PyDict_SetItemString(config, "main_config", dict) < 0) {
-        goto error;
+        return -1;
     }
-    Py_CLEAR(dict);
 
+    PyObject *res;
     PyObject *json = PyImport_ImportModule("json");
-    PyObject *res = PyObject_CallMethod(json, "dumps", "O", config);
+    if (json) {
+        res = PyObject_CallMethod(json, "dumps", "O", config);
         Py_DECREF(json);
+    }
+    else {
+        res = NULL;
+    }
     Py_CLEAR(config);
     if (res == NULL) {
-        goto error;
+        return -1;
     }
 
     PySys_FormatStdout("%S\n", res);
     Py_DECREF(res);
 
     return 0;
-
-error:
-    Py_XDECREF(config);
-    Py_XDECREF(dict);
-    return -1;
 }
 
 

Python/coreconfig.c

@@ -131,7 +131,7 @@ int Py_LegacyWindowsStdioFlag = 0; /* Uses FileIO instead of WindowsConsoleIO */
 #endif
 
 
-PyObject *
+static PyObject *
 _Py_GetGlobalVariablesAsDict(void)
 {
     PyObject *dict, *obj;
@@ -1563,7 +1563,7 @@ _PyCoreConfig_Write(const _PyCoreConfig *config)
 }
 
 
-PyObject *
+static PyObject *
 _PyCoreConfig_AsDict(const _PyCoreConfig *config)
 {
     PyObject *dict;
@@ -1573,11 +1573,6 @@ _PyCoreConfig_AsDict(const _PyCoreConfig *config)
         return NULL;
     }
 
-    if (_PyPreConfig_AsDict(&config->preconfig, dict) < 0) {
-        Py_DECREF(dict);
-        return NULL;
-    }
-
 #define SET_ITEM(KEY, EXPR) \
         do { \
             PyObject *obj = (EXPR); \
@@ -2158,3 +2153,67 @@ done:
     cmdline_clear(&cmdline);
     return err;
 }
+
+
+PyObject*
+_Py_GetConfigsAsDict(void)
+{
+    PyObject *config = NULL;
+    PyObject *dict = NULL;
+
+    config = PyDict_New();
+    if (config == NULL) {
+        goto error;
+    }
+
+    /* global config */
+    dict = _Py_GetGlobalVariablesAsDict();
+    if (dict == NULL) {
+        goto error;
+    }
+    if (PyDict_SetItemString(config, "global_config", dict) < 0) {
+        goto error;
+    }
+    Py_CLEAR(dict);
+
+    /* pre config */
+    PyInterpreterState *interp = _PyInterpreterState_Get();
+    const _PyCoreConfig *core_config = _PyInterpreterState_GetCoreConfig(interp);
+    const _PyPreConfig *pre_config = &core_config->preconfig;
+    dict = _PyPreConfig_AsDict(pre_config);
+    if (dict == NULL) {
+        goto error;
+    }
+    if (PyDict_SetItemString(config, "pre_config", dict) < 0) {
+        goto error;
+    }
+    Py_CLEAR(dict);
+
+    /* core config */
+    dict = _PyCoreConfig_AsDict(core_config);
+    if (dict == NULL) {
+        goto error;
+    }
+    if (PyDict_SetItemString(config, "core_config", dict) < 0) {
+        goto error;
+    }
+    Py_CLEAR(dict);
+
+    /* main config */
+    const _PyMainInterpreterConfig *main_config = _PyInterpreterState_GetMainConfig(interp);
+    dict = _PyMainInterpreterConfig_AsDict(main_config);
+    if (dict == NULL) {
+        goto error;
+    }
+    if (PyDict_SetItemString(config, "main_config", dict) < 0) {
+        goto error;
+    }
+    Py_CLEAR(dict);
+
+    return config;
+
+error:
+    Py_XDECREF(config);
+    Py_XDECREF(dict);
+    return NULL;
+}

Python/preconfig.c

@@ -574,9 +574,16 @@ _PyPreCmdline_SetPreConfig(const _PyPreCmdline *cmdline, _PyPreConfig *config)
 }
 
 
-int
-_PyPreConfig_AsDict(const _PyPreConfig *config, PyObject *dict)
+PyObject*
+_PyPreConfig_AsDict(const _PyPreConfig *config)
 {
+    PyObject *dict;
+
+    dict = PyDict_New();
+    if (dict == NULL) {
+        return NULL;
+    }
+
 #define SET_ITEM(KEY, EXPR) \
         do { \
             PyObject *obj = (EXPR); \
@@ -608,10 +615,11 @@ _PyPreConfig_AsDict(const _PyPreConfig *config, PyObject *dict)
 #endif
     SET_ITEM_INT(dev_mode);
     SET_ITEM_STR(allocator);
-    return 0;
+    return dict;
 
 fail:
-    return -1;
+    Py_DECREF(dict);
+    return NULL;
 
 #undef FROM_STRING
 #undef SET_ITEM