bpo-28411: Remove "modules" field from Py_InterpreterState. (#1638)

sys.modules is the one true source.

8 files changed, 207 insertions, 84 deletions

diff --git a/Python/_warnings.c b/Python/_warnings.c
index add72e4ebb..8616195c4e 100644
--- a/Python/_warnings.c
+++ b/Python/_warnings.c
@@ -44,7 +44,6 @@ static PyObject *
 get_warnings_attr(const char *attr, int try_import)
 {
     static PyObject *warnings_str = NULL;
-    PyObject *all_modules;
     PyObject *warnings_module, *obj;
 
     if (warnings_str == NULL) {
@@ -64,9 +63,7 @@ get_warnings_attr(const char *attr, int try_import)
         }
     }
     else {
-        all_modules = PyImport_GetModuleDict();
-
-        warnings_module = PyDict_GetItem(all_modules, warnings_str);
+        warnings_module = _PyImport_GetModule(warnings_str);
         if (warnings_module == NULL)
             return NULL;
 
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index 5e1f1d3854..c363cfe8ce 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -2685,7 +2685,7 @@ _PyBuiltin_Init(void)
         PyType_Ready(&PyZip_Type) < 0)
         return NULL;
 
-    mod = PyModule_Create(&builtinsmodule);
+    mod = _PyModule_CreateInitialized(&builtinsmodule, PYTHON_API_VERSION);
     if (mod == NULL)
         return NULL;
     dict = PyModule_GetDict(mod);
diff --git a/Python/ceval.c b/Python/ceval.c
index 92b1331135..436e5cad25 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -5054,7 +5054,7 @@ import_from(PyObject *v, PyObject *name)
         Py_DECREF(pkgname);
         return NULL;
     }
-    x = PyDict_GetItem(PyImport_GetModuleDict(), fullmodname);
+    x = _PyImport_GetModule(fullmodname);
     Py_DECREF(fullmodname);
     if (x == NULL) {
         goto error;
diff --git a/Python/import.c b/Python/import.c
index f27b7cb010..542a91b9e6 100644
--- a/Python/import.c
+++ b/Python/import.c
@@ -303,10 +303,115 @@ _PyImport_Fini(void)
 PyObject *
 PyImport_GetModuleDict(void)
 {
-    PyInterpreterState *interp = PyThreadState_GET()->interp;
-    if (interp->modules == NULL)
-        Py_FatalError("PyImport_GetModuleDict: no module dictionary!");
-    return interp->modules;
+    PyObject *sysdict = PyThreadState_GET()->interp->sysdict;
+    if (sysdict == NULL) {
+        Py_FatalError("PyImport_GetModuleDict: no sys module!");
+    }
+
+    _Py_IDENTIFIER(modules);
+    PyObject *modules = _PyDict_GetItemId(sysdict, &PyId_modules);
+    if (modules == NULL) {
+        Py_FatalError("lost sys.modules");
+    }
+    return modules;
+}
+
+/* In some corner cases it is important to be sure that the import
+   machinery has been initialized (or not cleaned up yet).  For
+   example, see issue #4236 and PyModule_Create2(). */
+
+int
+_PyImport_IsInitialized(PyInterpreterState *interp)
+{
+    if (interp->sysdict == NULL)
+        return 0;
+    _Py_IDENTIFIER(modules);
+    PyObject *modules = _PyDict_GetItemId(interp->sysdict, &PyId_modules);
+    if (modules == NULL)
+        return 0;
+    return 1;
+}
+
+PyObject *
+_PyImport_GetModule(PyObject *name)
+{
+    PyObject *modules = PyImport_GetModuleDict();
+    if (PyDict_CheckExact(modules)) {
+        return PyDict_GetItem(modules, name);
+    }
+
+    PyObject *mod = PyObject_GetItem(modules, name);
+    // For backward-comaptibility we copy the behavior of PyDict_GetItem().
+    if (PyErr_Occurred()) {
+        PyErr_Clear();
+    }
+    Py_XDECREF(mod);
+    return mod;
+}
+
+PyObject *
+_PyImport_GetModuleWithError(PyObject *name)
+{
+    PyObject *modules = PyImport_GetModuleDict();
+    if (PyDict_CheckExact(modules)) {
+        return PyDict_GetItemWithError(modules, name);
+    }
+
+    PyObject *mod = PyObject_GetItem(modules, name);
+    // For backward-comaptibility we copy the behavior
+    // of PyDict_GetItemWithError().
+    if (PyErr_ExceptionMatches(PyExc_KeyError)) {
+        PyErr_Clear();
+    }
+    return mod;
+}
+
+PyObject *
+_PyImport_GetModuleId(struct _Py_Identifier *nameid)
+{
+    PyObject *name = _PyUnicode_FromId(nameid); /* borrowed */
+    if (name == NULL) {
+        return NULL;
+    }
+    return _PyImport_GetModule(name);
+}
+
+int
+_PyImport_SetModule(PyObject *name, PyObject *m)
+{
+    PyObject *modules = PyImport_GetModuleDict();
+    return PyObject_SetItem(modules, name, m);
+}
+
+int
+_PyImport_SetModuleString(const char *name, PyObject *m)
+{
+    PyObject *modules = PyImport_GetModuleDict();
+    return PyMapping_SetItemString(modules, name, m);
+}
+
+PyObject *
+PyImport_GetModule(PyObject *name)
+{
+    PyObject *m;
+    PyObject *modules = PyImport_GetModuleDict();
+    if (modules == NULL) {
+        PyErr_SetString(PyExc_RuntimeError, "unable to get sys.modules");
+        return NULL;
+    }
+    Py_INCREF(modules);
+    if (PyDict_CheckExact(modules)) {
+        m = PyDict_GetItemWithError(modules, name);  /* borrowed */
+        Py_XINCREF(m);
+    }
+    else {
+        m = PyObject_GetItem(modules, name);
+        if (PyErr_ExceptionMatches(PyExc_KeyError)) {
+            PyErr_Clear();
+        }
+    }
+    Py_DECREF(modules);
+    return m;
 }
 
 
@@ -336,7 +441,7 @@ PyImport_Cleanup(void)
     Py_ssize_t pos;
     PyObject *key, *value, *dict;
     PyInterpreterState *interp = PyThreadState_GET()->interp;
-    PyObject *modules = interp->modules;
+    PyObject *modules = PyImport_GetModuleDict();
     PyObject *weaklist = NULL;
     const char * const *p;
 
@@ -398,7 +503,7 @@ PyImport_Cleanup(void)
             if (Py_VerboseFlag && PyUnicode_Check(key))
                 PySys_FormatStderr("# cleanup[2] removing %U\n", key);
             STORE_MODULE_WEAKREF(key, value);
-            PyDict_SetItem(modules, key, Py_None);
+            PyObject_SetItem(modules, key, Py_None);
         }
     }
 
@@ -465,7 +570,6 @@ PyImport_Cleanup(void)
     /* Clear and delete the modules directory.  Actual modules will
        still be there only if imported during the execution of some
        destructor. */
-    interp->modules = NULL;
     Py_DECREF(modules);
 
     /* Once more */
@@ -524,9 +628,9 @@ PyImport_GetMagicTag(void)
 
 int
 _PyImport_FixupExtensionObject(PyObject *mod, PyObject *name,
-                               PyObject *filename)
+                                 PyObject *filename, PyObject *modules)
 {
-    PyObject *modules, *dict, *key;
+    PyObject *dict, *key;
     struct PyModuleDef *def;
     int res;
     if (extensions == NULL) {
@@ -543,11 +647,10 @@ _PyImport_FixupExtensionObject(PyObject *mod, PyObject *name,
         PyErr_BadInternalCall();
         return -1;
     }
-    modules = PyImport_GetModuleDict();
-    if (PyDict_SetItem(modules, name, mod) < 0)
+    if (PyObject_SetItem(modules, name, mod) < 0)
         return -1;
     if (_PyState_AddModule(mod, def) < 0) {
-        PyDict_DelItem(modules, name);
+        PyMapping_DelItem(modules, name);
         return -1;
     }
     if (def->m_size == -1) {
@@ -575,14 +678,14 @@ _PyImport_FixupExtensionObject(PyObject *mod, PyObject *name,
 }
 
 int
-_PyImport_FixupBuiltin(PyObject *mod, const char *name)
+_PyImport_FixupBuiltin(PyObject *mod, const char *name, PyObject *modules)
 {
     int res;
     PyObject *nameobj;
     nameobj = PyUnicode_InternFromString(name);
     if (nameobj == NULL)
         return -1;
-    res = _PyImport_FixupExtensionObject(mod, nameobj, nameobj);
+    res = _PyImport_FixupExtensionObject(mod, nameobj, nameobj, modules);
     Py_DECREF(nameobj);
     return res;
 }
@@ -590,6 +693,14 @@ _PyImport_FixupBuiltin(PyObject *mod, const char *name)
 PyObject *
 _PyImport_FindExtensionObject(PyObject *name, PyObject *filename)
 {
+    PyObject *modules = PyImport_GetModuleDict();
+    return _PyImport_FindExtensionObjectEx(name, filename, modules);
+}
+
+PyObject *
+_PyImport_FindExtensionObjectEx(PyObject *name, PyObject *filename,
+                                PyObject *modules)
+{
     PyObject *mod, *mdict, *key;
     PyModuleDef* def;
     if (extensions == NULL)
@@ -605,7 +716,7 @@ _PyImport_FindExtensionObject(PyObject *name, PyObject *filename)
         /* Module does not support repeated initialization */
         if (def->m_base.m_copy == NULL)
             return NULL;
-        mod = PyImport_AddModuleObject(name);
+        mod = _PyImport_AddModuleObject(name, modules);
         if (mod == NULL)
             return NULL;
         mdict = PyModule_GetDict(mod);
@@ -620,14 +731,14 @@ _PyImport_FindExtensionObject(PyObject *name, PyObject *filename)
         mod = def->m_base.m_init();
         if (mod == NULL)
             return NULL;
-        if (PyDict_SetItem(PyImport_GetModuleDict(), name, mod) == -1) {
+        if (PyObject_SetItem(modules, name, mod) == -1) {
             Py_DECREF(mod);
             return NULL;
         }
         Py_DECREF(mod);
     }
     if (_PyState_AddModule(mod, def) < 0) {
-        PyDict_DelItem(PyImport_GetModuleDict(), name);
+        PyMapping_DelItem(modules, name);
         Py_DECREF(mod);
         return NULL;
     }
@@ -639,13 +750,13 @@ _PyImport_FindExtensionObject(PyObject *name, PyObject *filename)
 }
 
 PyObject *
-_PyImport_FindBuiltin(const char *name)
+_PyImport_FindBuiltin(const char *name, PyObject *modules)
 {
     PyObject *res, *nameobj;
     nameobj = PyUnicode_InternFromString(name);
     if (nameobj == NULL)
         return NULL;
-    res = _PyImport_FindExtensionObject(nameobj, nameobj);
+    res = _PyImport_FindExtensionObjectEx(nameobj, nameobj, modules);
     Py_DECREF(nameobj);
     return res;
 }
@@ -660,19 +771,34 @@ PyObject *
 PyImport_AddModuleObject(PyObject *name)
 {
     PyObject *modules = PyImport_GetModuleDict();
-    PyObject *m;
+    return _PyImport_AddModuleObject(name, modules);
+}
 
-    if ((m = PyDict_GetItemWithError(modules, name)) != NULL &&
-        PyModule_Check(m)) {
-        return m;
+PyObject *
+_PyImport_AddModuleObject(PyObject *name, PyObject *modules)
+{
+    PyObject *m;
+    if (PyDict_CheckExact(modules)) {
+        m = PyDict_GetItemWithError(modules, name);
+    }
+    else {
+        m = PyObject_GetItem(modules, name);
+        // For backward-comaptibility we copy the behavior
+        // of PyDict_GetItemWithError().
+        if (PyErr_ExceptionMatches(PyExc_KeyError)) {
+            PyErr_Clear();
+        }
     }
     if (PyErr_Occurred()) {
         return NULL;
     }
+    if (m != NULL && PyModule_Check(m)) {
+        return m;
+    }
     m = PyModule_NewObject(name);
     if (m == NULL)
         return NULL;
-    if (PyDict_SetItem(modules, name, m) != 0) {
+    if (PyObject_SetItem(modules, name, m) != 0) {
         Py_DECREF(m);
         return NULL;
     }
@@ -699,11 +825,13 @@ static void
 remove_module(PyObject *name)
 {
     PyObject *modules = PyImport_GetModuleDict();
-    if (PyDict_GetItem(modules, name) == NULL)
-        return;
-    if (PyDict_DelItem(modules, name) < 0)
+    if (PyMapping_DelItem(modules, name) < 0) {
+        if (!PyMapping_HasKey(modules, name)) {
+            return;
+        }
         Py_FatalError("import:  deleting existing key in"
                       "sys.modules failed");
+    }
 }
 
 
@@ -812,7 +940,6 @@ module_dict_for_exec(PyObject *name)
 static PyObject *
 exec_code_in_module(PyObject *name, PyObject *module_dict, PyObject *code_object)
 {
-    PyObject *modules = PyImport_GetModuleDict();
     PyObject *v, *m;
 
     v = PyEval_EvalCode(code_object, module_dict, module_dict);
@@ -822,7 +949,8 @@ exec_code_in_module(PyObject *name, PyObject *module_dict, PyObject *code_object
     }
     Py_DECREF(v);
 
-    if ((m = PyDict_GetItem(modules, name)) == NULL) {
+    m = _PyImport_GetModule(name);
+    if (m == NULL) {
         PyErr_Format(PyExc_ImportError,
                      "Loaded module %R not found in sys.modules",
                      name);
@@ -1055,6 +1183,7 @@ _imp_create_builtin(PyObject *module, PyObject *spec)
         return NULL;
     }
 
+    PyObject *modules = NULL;
     for (p = PyImport_Inittab; p->name != NULL; p++) {
         PyModuleDef *def;
         if (_PyUnicode_EqualToASCIIString(name, p->name)) {
@@ -1080,7 +1209,11 @@ _imp_create_builtin(PyObject *module, PyObject *spec)
                     return NULL;
                 }
                 def->m_base.m_init = p->initfunc;
-                if (_PyImport_FixupExtensionObject(mod, name, name) < 0) {
+                if (modules == NULL) {
+                    modules = PyImport_GetModuleDict();
+                }
+                if (_PyImport_FixupExtensionObject(mod, name, name,
+                                                   modules) < 0) {
                     Py_DECREF(name);
                     return NULL;
                 }
@@ -1524,7 +1657,7 @@ PyImport_ImportModuleLevelObject(PyObject *name, PyObject *globals,
         Py_INCREF(abs_name);
     }
 
-    mod = PyDict_GetItem(interp->modules, abs_name);
+    mod = _PyImport_GetModule(abs_name);
     if (mod != NULL && mod != Py_None) {
         _Py_IDENTIFIER(__spec__);
         _Py_IDENTIFIER(_initializing);
@@ -1611,7 +1744,7 @@ PyImport_ImportModuleLevelObject(PyObject *name, PyObject *globals,
                     goto error;
                 }
 
-                final_mod = PyDict_GetItem(interp->modules, to_return);
+                final_mod = _PyImport_GetModule(to_return);
                 Py_DECREF(to_return);
                 if (final_mod == NULL) {
                     PyErr_Format(PyExc_KeyError,
@@ -1664,10 +1797,10 @@ PyImport_ImportModuleLevel(const char *name, PyObject *globals, PyObject *locals
 PyObject *
 PyImport_ReloadModule(PyObject *m)
 {
+    _Py_IDENTIFIER(imp);
     _Py_IDENTIFIER(reload);
     PyObject *reloaded_module = NULL;
-    PyObject *modules = PyImport_GetModuleDict();
-    PyObject *imp = PyDict_GetItemString(modules, "imp");
+    PyObject *imp = _PyImport_GetModuleId(&PyId_imp);
     if (imp == NULL) {
         imp = PyImport_ImportModule("imp");
         if (imp == NULL) {
@@ -1702,7 +1835,6 @@ PyImport_Import(PyObject *module_name)
     PyObject *globals = NULL;
     PyObject *import = NULL;
     PyObject *builtins = NULL;
-    PyObject *modules = NULL;
     PyObject *r = NULL;
 
     /* Initialize constant string objects */
@@ -1757,8 +1889,7 @@ PyImport_Import(PyObject *module_name)
         goto err;
     Py_DECREF(r);
 
-    modules = PyImport_GetModuleDict();
-    r = PyDict_GetItemWithError(modules, module_name);
+    r = _PyImport_GetModule(module_name);
     if (r != NULL) {
         Py_INCREF(r);
     }
diff --git a/Python/importdl.c b/Python/importdl.c
index d8656b9433..32fb7e1be2 100644
--- a/Python/importdl.c
+++ b/Python/importdl.c
@@ -215,7 +215,8 @@ _PyImport_LoadDynamicModuleWithSpec(PyObject *spec, FILE *fp)
     else
         Py_INCREF(path);
 
-    if (_PyImport_FixupExtensionObject(m, name_unicode, path) < 0)
+    PyObject *modules = PyImport_GetModuleDict();
+    if (_PyImport_FixupExtensionObject(m, name_unicode, path, modules) < 0)
         goto error;
 
     Py_DECREF(name_unicode);
diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index eaa7b7f459..662405bdeb 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -41,6 +41,7 @@ _Py_IDENTIFIER(name);
 _Py_IDENTIFIER(stdin);
 _Py_IDENTIFIER(stdout);
 _Py_IDENTIFIER(stderr);
+_Py_IDENTIFIER(threading);
 
 #ifdef __cplusplus
 extern "C" {
@@ -262,7 +263,6 @@ initimport(PyInterpreterState *interp, PyObject *sysmod)
 {
     PyObject *importlib;
     PyObject *impmod;
-    PyObject *sys_modules;
     PyObject *value;
 
     /* Import _importlib through its frozen version, _frozen_importlib. */
@@ -293,11 +293,7 @@ initimport(PyInterpreterState *interp, PyObject *sysmod)
     else if (Py_VerboseFlag) {
         PySys_FormatStderr("import _imp # builtin\n");
     }
-    sys_modules = PyImport_GetModuleDict();
-    if (Py_VerboseFlag) {
-        PySys_FormatStderr("import sys # builtin\n");
-    }
-    if (PyDict_SetItemString(sys_modules, "_imp", impmod) < 0) {
+    if (_PyImport_SetModuleString("_imp", impmod) < 0) {
         Py_FatalError("Py_Initialize: can't save _imp to sys.modules");
     }
 
@@ -647,10 +643,20 @@ void _Py_InitializeCore(const _PyCoreConfig *config)
     if (!_PyFloat_Init())
         Py_FatalError("Py_InitializeCore: can't init float");
 
-    interp->modules = PyDict_New();
-    if (interp->modules == NULL)
+    PyObject *modules = PyDict_New();
+    if (modules == NULL)
         Py_FatalError("Py_InitializeCore: can't make modules dictionary");
 
+    sysmod = _PySys_BeginInit();
+    if (sysmod == NULL)
+        Py_FatalError("Py_InitializeCore: can't initialize sys");
+    interp->sysdict = PyModule_GetDict(sysmod);
+    if (interp->sysdict == NULL)
+        Py_FatalError("Py_InitializeCore: can't initialize sys dict");
+    Py_INCREF(interp->sysdict);
+    PyDict_SetItemString(interp->sysdict, "modules", modules);
+    _PyImport_FixupBuiltin(sysmod, "sys", modules);
+
     /* Init Unicode implementation; relies on the codec registry */
     if (_PyUnicode_Init() < 0)
         Py_FatalError("Py_InitializeCore: can't initialize unicode");
@@ -661,7 +667,7 @@ void _Py_InitializeCore(const _PyCoreConfig *config)
     bimod = _PyBuiltin_Init();
     if (bimod == NULL)
         Py_FatalError("Py_InitializeCore: can't initialize builtins modules");
-    _PyImport_FixupBuiltin(bimod, "builtins");
+    _PyImport_FixupBuiltin(bimod, "builtins", modules);
     interp->builtins = PyModule_GetDict(bimod);
     if (interp->builtins == NULL)
         Py_FatalError("Py_InitializeCore: can't initialize builtins dict");
@@ -670,17 +676,6 @@ void _Py_InitializeCore(const _PyCoreConfig *config)
     /* initialize builtin exceptions */
     _PyExc_Init(bimod);
 
-    sysmod = _PySys_BeginInit();
-    if (sysmod == NULL)
-        Py_FatalError("Py_InitializeCore: can't initialize sys");
-    interp->sysdict = PyModule_GetDict(sysmod);
-    if (interp->sysdict == NULL)
-        Py_FatalError("Py_InitializeCore: can't initialize sys dict");
-    Py_INCREF(interp->sysdict);
-    _PyImport_FixupBuiltin(sysmod, "sys");
-    PyDict_SetItemString(interp->sysdict, "modules",
-                         interp->modules);
-
     /* Set up a preliminary stderr printer until we have enough
        infrastructure for the io module in place. */
     pstderr = PyFile_NewStdPrinter(fileno(stderr));
@@ -1178,9 +1173,22 @@ Py_NewInterpreter(void)
 
     /* XXX The following is lax in error checking */
 
-    interp->modules = PyDict_New();
+    PyObject *modules = PyDict_New();
+    if (modules == NULL)
+        Py_FatalError("Py_NewInterpreter: can't make modules dictionary");
 
-    bimod = _PyImport_FindBuiltin("builtins");
+    sysmod = _PyImport_FindBuiltin("sys", modules);
+    if (sysmod != NULL) {
+        interp->sysdict = PyModule_GetDict(sysmod);
+        if (interp->sysdict == NULL)
+            goto handle_error;
+        Py_INCREF(interp->sysdict);
+        PyDict_SetItemString(interp->sysdict, "modules", modules);
+        PySys_SetPath(Py_GetPath());
+        _PySys_EndInit(interp->sysdict);
+    }
+
+    bimod = _PyImport_FindBuiltin("builtins", modules);
     if (bimod != NULL) {
         interp->builtins = PyModule_GetDict(bimod);
         if (interp->builtins == NULL)
@@ -1191,18 +1199,9 @@ Py_NewInterpreter(void)
     /* initialize builtin exceptions */
     _PyExc_Init(bimod);
 
-    sysmod = _PyImport_FindBuiltin("sys");
     if (bimod != NULL && sysmod != NULL) {
         PyObject *pstderr;
 
-        interp->sysdict = PyModule_GetDict(sysmod);
-        if (interp->sysdict == NULL)
-            goto handle_error;
-        Py_INCREF(interp->sysdict);
-        _PySys_EndInit(interp->sysdict);
-        PySys_SetPath(Py_GetPath());
-        PyDict_SetItemString(interp->sysdict, "modules",
-                             interp->modules);
         /* Set up a preliminary stderr printer until we have enough
            infrastructure for the io module in place. */
         pstderr = PyFile_NewStdPrinter(fileno(stderr));
@@ -1882,14 +1881,13 @@ wait_for_thread_shutdown(void)
 #ifdef WITH_THREAD
     _Py_IDENTIFIER(_shutdown);
     PyObject *result;
-    PyThreadState *tstate = PyThreadState_GET();
-    PyObject *threading = PyMapping_GetItemString(tstate->interp->modules,
-                                                  "threading");
+    PyObject *threading = _PyImport_GetModuleId(&PyId_threading);
     if (threading == NULL) {
         /* threading not imported */
         PyErr_Clear();
         return;
     }
+    Py_INCREF(threading);
     result = _PyObject_CallMethodId(threading, &PyId__shutdown, NULL);
     if (result == NULL) {
         PyErr_WriteUnraisable(threading);
diff --git a/Python/pystate.c b/Python/pystate.c
index 24a08ebf4f..30a372212e 100644
--- a/Python/pystate.c
+++ b/Python/pystate.c
@@ -97,7 +97,6 @@ PyInterpreterState_New(void)
         if (head_mutex == NULL)
             Py_FatalError("Can't initialize threads for interpreter");
 #endif
-        interp->modules = NULL;
         interp->modules_by_index = NULL;
         interp->sysdict = NULL;
         interp->builtins = NULL;
@@ -158,7 +157,6 @@ PyInterpreterState_Clear(PyInterpreterState *interp)
     Py_CLEAR(interp->codec_search_path);
     Py_CLEAR(interp->codec_search_cache);
     Py_CLEAR(interp->codec_error_registry);
-    Py_CLEAR(interp->modules);
     Py_CLEAR(interp->modules_by_index);
     Py_CLEAR(interp->sysdict);
     Py_CLEAR(interp->builtins);
diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index ab435c8310..852babbed7 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -159,13 +159,11 @@ static PyObject *
 sys_displayhook(PyObject *self, PyObject *o)
 {
     PyObject *outf;
-    PyInterpreterState *interp = PyThreadState_GET()->interp;
-    PyObject *modules = interp->modules;
     PyObject *builtins;
     static PyObject *newline = NULL;
     int err;
 
-    builtins = _PyDict_GetItemId(modules, &PyId_builtins);
+    builtins = _PyImport_GetModuleId(&PyId_builtins);
     if (builtins == NULL) {
         PyErr_SetString(PyExc_RuntimeError, "lost builtins module");
         return NULL;
@@ -1929,7 +1927,7 @@ _PySys_BeginInit(void)
     PyObject *m, *sysdict, *version_info;
     int res;
 
-    m = PyModule_Create(&sysmodule);
+    m = _PyModule_CreateInitialized(&sysmodule, PYTHON_API_VERSION);
     if (m == NULL)
         return NULL;
     sysdict = PyModule_GetDict(m);