bpo-36710: Add tstate parameter in import.c (GH-14218)

* Add 'tstate' parameter to many internal import.c functions.
* _PyImportZip_Init() now gets 'tstate' parameter rather than
  'interp'.
* Add 'interp' parameter to _PyState_ClearModules() and rename it
  to _PyInterpreterState_ClearModules().
* Move private _PyImport_FindBuiltin() to the internal C API; add
  'tstate' parameter to it.
* Remove private _PyImport_AddModuleObject() from the C API:
  use public PyImport_AddModuleObject() instead.
* Remove private _PyImport_FindExtensionObjectEx() from the C API:
  use private _PyImport_FindExtensionObject() instead.

Include/cpython/import.h

@@ -11,21 +11,14 @@ PyMODINIT_FUNC PyInit__imp(void);
 PyAPI_FUNC(int) _PyImport_IsInitialized(PyInterpreterState *);
 
 PyAPI_FUNC(PyObject *) _PyImport_GetModuleId(struct _Py_Identifier *name);
-PyAPI_FUNC(PyObject *) _PyImport_AddModuleObject(PyObject *name,
-                                                 PyObject *modules);
 PyAPI_FUNC(int) _PyImport_SetModule(PyObject *name, PyObject *module);
 PyAPI_FUNC(int) _PyImport_SetModuleString(const char *name, PyObject* module);
 
 PyAPI_FUNC(void) _PyImport_AcquireLock(void);
 PyAPI_FUNC(int) _PyImport_ReleaseLock(void);
 
-PyAPI_FUNC(PyObject *) _PyImport_FindBuiltin(
-    const char *name,            /* UTF-8 encoded string */
-    PyObject *modules
-    );
 PyAPI_FUNC(PyObject *) _PyImport_FindExtensionObject(PyObject *, PyObject *);
-PyAPI_FUNC(PyObject *) _PyImport_FindExtensionObjectEx(PyObject *, PyObject *,
-                                                       PyObject *);
+
 PyAPI_FUNC(int) _PyImport_FixupBuiltin(
     PyObject *mod,
     const char *name,            /* UTF-8 encoded string */

Include/cpython/pystate.h

@@ -148,7 +148,6 @@ struct _ts {
 PyAPI_FUNC(PyInterpreterState *) _PyInterpreterState_Get(void);
 
 PyAPI_FUNC(int) _PyState_AddModule(PyObject*, struct PyModuleDef*);
-PyAPI_FUNC(void) _PyState_ClearModules(void);
 PyAPI_FUNC(PyThreadState *) _PyThreadState_Prealloc(PyInterpreterState *);
 
 /* Similar to PyThreadState_Get(), but don't issue a fatal error

Include/internal/pycore_import.h

@@ -5,6 +5,11 @@
 extern "C" {
 #endif
 
+PyAPI_FUNC(PyObject *) _PyImport_FindBuiltin(
+    PyThreadState *tstate,
+    const char *name             /* UTF-8 encoded string */
+    );
+
 extern void _PyImport_ReInitLock(void);
 
 #ifdef __cplusplus

Include/internal/pycore_pylifecycle.h

@@ -55,7 +55,7 @@ extern int _PyFloat_Init(void);
 extern PyStatus _Py_HashRandomization_Init(const PyConfig *);
 
 extern PyStatus _PyTypes_Init(void);
-extern PyStatus _PyImportZip_Init(PyInterpreterState *interp);
+extern PyStatus _PyImportZip_Init(PyThreadState *tstate);
 
 
 /* Various internal finalizers */

Include/internal/pycore_pystate.h

@@ -310,6 +310,9 @@ PyAPI_FUNC(PyThreadState *) _PyThreadState_Swap(
 PyAPI_FUNC(PyStatus) _PyInterpreterState_Enable(_PyRuntimeState *runtime);
 PyAPI_FUNC(void) _PyInterpreterState_DeleteExceptMain(_PyRuntimeState *runtime);
 
+/* Used by PyImport_Cleanup() */
+extern void _PyInterpreterState_ClearModules(PyInterpreterState *interp);
+
 PyAPI_FUNC(void) _PyGILState_Reinit(_PyRuntimeState *runtime);
 
 #ifdef __cplusplus

Python/pylifecycle.c

@@ -6,6 +6,7 @@
 #undef Yield   /* undefine macro conflicting with <winbase.h> */
 #include "pycore_ceval.h"
 #include "pycore_context.h"
+#include "pycore_import.h"   /* _PyImport_FindBuiltin */
 #include "pycore_initconfig.h"
 #include "pycore_fileutils.h"
 #include "pycore_hamt.h"
@@ -197,17 +198,17 @@ init_importlib(PyInterpreterState *interp, PyObject *sysmod)
 }
 
 static PyStatus
-init_importlib_external(PyInterpreterState *interp)
+init_importlib_external(PyThreadState *tstate)
 {
     PyObject *value;
-    value = PyObject_CallMethod(interp->importlib,
+    value = PyObject_CallMethod(tstate->interp->importlib,
                                 "_install_external_importers", "");
     if (value == NULL) {
         PyErr_Print();
         return _PyStatus_ERR("external importer setup failed");
     }
     Py_DECREF(value);
-    return _PyImportZip_Init(interp);
+    return _PyImportZip_Init(tstate);
 }
 
 /* Helper functions to better handle the legacy C locale
@@ -924,7 +925,7 @@ pyinit_main(_PyRuntimeState *runtime, PyInterpreterState *interp)
         return _PyStatus_ERR("can't finish initializing sys");
     }
 
-    PyStatus status = init_importlib_external(interp);
+    PyStatus status = init_importlib_external(tstate);
     if (_PyStatus_EXCEPTION(status)) {
         return status;
     }
@@ -1449,7 +1450,7 @@ new_interpreter(PyThreadState **tstate_p)
     }
     interp->modules = modules;
 
-    PyObject *sysmod = _PyImport_FindBuiltin("sys", modules);
+    PyObject *sysmod = _PyImport_FindBuiltin(tstate, "sys");
     if (sysmod != NULL) {
         interp->sysdict = PyModule_GetDict(sysmod);
         if (interp->sysdict == NULL) {
@@ -1465,7 +1466,7 @@ new_interpreter(PyThreadState **tstate_p)
         goto handle_error;
     }
 
-    PyObject *bimod = _PyImport_FindBuiltin("builtins", modules);
+    PyObject *bimod = _PyImport_FindBuiltin(tstate, "builtins");
     if (bimod != NULL) {
         interp->builtins = PyModule_GetDict(bimod);
         if (interp->builtins == NULL)
@@ -1497,7 +1498,7 @@ new_interpreter(PyThreadState **tstate_p)
             return status;
         }
 
-        status = init_importlib_external(interp);
+        status = init_importlib_external(tstate);
         if (_PyStatus_EXCEPTION(status)) {
             return status;
         }

Python/pystate.c

@@ -741,28 +741,32 @@ PyState_RemoveModule(struct PyModuleDef* def)
     return PyList_SetItem(state->modules_by_index, index, Py_None);
 }
 
-/* used by import.c:PyImport_Cleanup */
+/* Used by PyImport_Cleanup() */
 void
-_PyState_ClearModules(void)
+_PyInterpreterState_ClearModules(PyInterpreterState *interp)
 {
-    PyInterpreterState *state = _PyInterpreterState_GET_UNSAFE();
-    if (state->modules_by_index) {
+    if (!interp->modules_by_index) {
+        return;
+    }
+
     Py_ssize_t i;
-        for (i = 0; i < PyList_GET_SIZE(state->modules_by_index); i++) {
-            PyObject *m = PyList_GET_ITEM(state->modules_by_index, i);
+    for (i = 0; i < PyList_GET_SIZE(interp->modules_by_index); i++) {
+        PyObject *m = PyList_GET_ITEM(interp->modules_by_index, i);
         if (PyModule_Check(m)) {
             /* cleanup the saved copy of module dicts */
             PyModuleDef *md = PyModule_GetDef(m);
-                if (md)
+            if (md) {
                 Py_CLEAR(md->m_base.m_copy);
             }
         }
+    }
+
     /* Setting modules_by_index to NULL could be dangerous, so we
        clear the list instead. */
-        if (PyList_SetSlice(state->modules_by_index,
-                            0, PyList_GET_SIZE(state->modules_by_index),
-                            NULL))
-            PyErr_WriteUnraisable(state->modules_by_index);
+    if (PyList_SetSlice(interp->modules_by_index,
+                        0, PyList_GET_SIZE(interp->modules_by_index),
+                        NULL)) {
+        PyErr_WriteUnraisable(interp->modules_by_index);
     }
 }