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.

2 files changed, 78 insertions, 11 deletions

diff --git a/Python/coreconfig.c b/Python/coreconfig.c
index ba5abb6..a434b25 100644
--- a/Python/coreconfig.c
+++ b/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;
+}
diff --git a/Python/preconfig.c b/Python/preconfig.c
index ac87a7a..c65ee28 100644
--- a/Python/preconfig.c
+++ b/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