Add _PyImport_CheckSubinterpIncompatibleExtensionAllowed().

ericsnowcurrently · ericsnowcurrently · commit eb7d1ce08e4b · 2022-11-02T20:11:39.000-06:00
diff --git a/Include/internal/pycore_import.h b/Include/internal/pycore_import.h
@@ -20,6 +20,9 @@ PyAPI_DATA(const struct _frozen *) _PyImport_FrozenStdlib;
 PyAPI_DATA(const struct _frozen *) _PyImport_FrozenTest;
 extern const struct _module_alias * _PyImport_FrozenAliases;
 
+PyAPI_FUNC(int) _PyImport_CheckSubinterpIncompatibleExtensionAllowed(
+    const char *name);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/Python/import.c b/Python/import.c
@@ -2330,6 +2330,21 @@ exec_builtin_or_dynamic(PyObject *mod) {
     return PyModule_ExecDef(mod, def);
 }
 
+int
+_PyImport_CheckSubinterpIncompatibleExtensionAllowed(const char *name)
+{
+    PyInterpreterState *interp = _PyInterpreterState_Get();
+    if (_PyInterpreterState_HasFeature(
+                interp, Py_RTFLAGS_MULTI_INTERP_EXTENSIONS)) {
+        assert(!_Py_IsMainInterpreter(interp));
+        PyErr_Format(PyExc_ImportError,
+                     "module %s does not support loading in subinterpreters",
+                     name);
+        return -1;
+    }
+    return 0;
+}
+
 #ifdef HAVE_DYNAMIC_LOADING
 
 /*[clinic input]

Original file line number	Diff line number	Diff line change
`@@ -20,6 +20,9 @@ PyAPI_DATA(const struct _frozen *) _PyImport_FrozenStdlib;`
`20`	`20`	`PyAPI_DATA(const struct _frozen *) _PyImport_FrozenTest;`
`21`	`21`	`extern const struct _module_alias * _PyImport_FrozenAliases;`
`22`	`22`
	`23`	`+PyAPI_FUNC(int) _PyImport_CheckSubinterpIncompatibleExtensionAllowed(`
	`24`	`+ const char *name);`
	`25`	`+`
`23`	`26`	`#ifdef __cplusplus`
`24`	`27`	`}`
`25`	`28`	`#endif`