bpo-35444: Unify and optimize the helper for getting a builtin object. (GH-11047)

This speeds up pickling of some iterators.

This fixes also error handling in pickling methods when fail to
look up builtin "getattr".

Include/ceval.h

@@ -48,10 +48,12 @@ PyAPI_FUNC(PyObject *) PyEval_GetGlobals(void);
 PyAPI_FUNC(PyObject *) PyEval_GetLocals(void);
 PyAPI_FUNC(struct _frame *) PyEval_GetFrame(void);
 
+#ifndef Py_LIMITED_API
+/* Helper to look up a builtin object */
+PyAPI_FUNC(PyObject *) _PyEval_GetBuiltinId(_Py_Identifier *);
 /* Look at the current frame's (if any) code's co_flags, and turn on
    the corresponding compiler flags in cf->cf_flags.  Return 1 if any
    flag was set, else return 0. */
-#ifndef Py_LIMITED_API
 PyAPI_FUNC(int) PyEval_MergeCompilerFlags(PyCompilerFlags *cf);
 #endif
 

Include/cpython/object.h

@@ -330,9 +330,6 @@ PyAPI_FUNC(int)
 _PyObject_GenericSetAttrWithDict(PyObject *, PyObject *,
                                  PyObject *, PyObject *);
 
-/* Helper to look up a builtin object */
-PyAPI_FUNC(PyObject *) _PyObject_GetBuiltin(const char *name);
-
 #define PyType_HasFeature(t,f)  (((t)->tp_flags & (f)) != 0)
 
 static inline void _Py_Dealloc_inline(PyObject *op)

Misc/NEWS.d/next/Core and Builtins/2018-12-09-13-09-39.bpo-35444.9kYn4V.rst

@@ -0,0 +1,2 @@
+Fixed error handling in pickling methods when fail to look up builtin
+"getattr". Sped up pickling iterators.

Modules/_pickle.c

@@ -209,19 +209,15 @@ _Pickle_ClearState(PickleState *st)
 static int
 _Pickle_InitState(PickleState *st)
 {
-    PyObject *builtins;
     PyObject *copyreg = NULL;
     PyObject *compat_pickle = NULL;
     PyObject *codecs = NULL;
     PyObject *functools = NULL;
+    _Py_IDENTIFIER(getattr);
 
-    builtins = PyEval_GetBuiltins();
-    if (builtins == NULL)
-        goto error;
-    st->getattr = PyDict_GetItemString(builtins, "getattr");
+    st->getattr = _PyEval_GetBuiltinId(&PyId_getattr);
     if (st->getattr == NULL)
         goto error;
-    Py_INCREF(st->getattr);
 
     copyreg = PyImport_ImportModule("copyreg");
     if (!copyreg)

Modules/arraymodule.c

@@ -2943,7 +2943,8 @@ static PyObject *
 array_arrayiterator___reduce___impl(arrayiterobject *self)
 /*[clinic end generated code: output=7898a52e8e66e016 input=a062ea1e9951417a]*/
 {
-    PyObject *func = _PyObject_GetBuiltin("iter");
+    _Py_IDENTIFIER(iter);
+    PyObject *func = _PyEval_GetBuiltinId(&PyId_iter);
     if (self->ao == NULL) {
         return Py_BuildValue("N(())", func);
     }

Modules/itertoolsmodule.c

@@ -368,8 +368,9 @@ _grouper_next(_grouperobject *igo)
 static PyObject *
 _grouper_reduce(_grouperobject *lz, PyObject *Py_UNUSED(ignored))
 {
+    _Py_IDENTIFIER(iter);
     if (((groupbyobject *)lz->parent)->currgrouper != lz) {
-        return Py_BuildValue("N(())", _PyObject_GetBuiltin("iter"));
+        return Py_BuildValue("N(())", _PyEval_GetBuiltinId(&PyId_iter));
     }
     return Py_BuildValue("O(OO)", Py_TYPE(lz), lz->parent, lz->tgtkey);
 }

Objects/bytearrayobject.c

@@ -2358,11 +2358,12 @@ PyDoc_STRVAR(length_hint_doc,
 static PyObject *
 bytearrayiter_reduce(bytesiterobject *it, PyObject *Py_UNUSED(ignored))
 {
+    _Py_IDENTIFIER(iter);
     if (it->it_seq != NULL) {
-        return Py_BuildValue("N(O)n", _PyObject_GetBuiltin("iter"),
+        return Py_BuildValue("N(O)n", _PyEval_GetBuiltinId(&PyId_iter),
                              it->it_seq, it->it_index);
     } else {
-        return Py_BuildValue("N(())", _PyObject_GetBuiltin("iter"));
+        return Py_BuildValue("N(())", _PyEval_GetBuiltinId(&PyId_iter));
     }
 }
 

Objects/bytesobject.c

@@ -3089,11 +3089,12 @@ PyDoc_STRVAR(length_hint_doc,
 static PyObject *
 striter_reduce(striterobject *it, PyObject *Py_UNUSED(ignored))
 {
+    _Py_IDENTIFIER(iter);
     if (it->it_seq != NULL) {
-        return Py_BuildValue("N(O)n", _PyObject_GetBuiltin("iter"),
+        return Py_BuildValue("N(O)n", _PyEval_GetBuiltinId(&PyId_iter),
                              it->it_seq, it->it_index);
     } else {
-        return Py_BuildValue("N(())", _PyObject_GetBuiltin("iter"));
+        return Py_BuildValue("N(())", _PyEval_GetBuiltinId(&PyId_iter));
     }
 }
 

Objects/classobject.c

@@ -78,8 +78,6 @@ method_reduce(PyMethodObject *im, PyObject *Py_UNUSED(ignored))
 {
     PyObject *self = PyMethod_GET_SELF(im);
     PyObject *func = PyMethod_GET_FUNCTION(im);
-    PyObject *builtins;
-    PyObject *getattr;
     PyObject *funcname;
     _Py_IDENTIFIER(getattr);
 
@@ -87,9 +85,8 @@ method_reduce(PyMethodObject *im, PyObject *Py_UNUSED(ignored))
     if (funcname == NULL) {
         return NULL;
     }
-    builtins = PyEval_GetBuiltins();
-    getattr = _PyDict_GetItemId(builtins, &PyId_getattr);
-    return Py_BuildValue("O(ON)", getattr, self, funcname);
+    return Py_BuildValue("N(ON)", _PyEval_GetBuiltinId(&PyId_getattr),
+                         self, funcname);
 }
 
 static PyMethodDef method_methods[] = {

Objects/descrobject.c

@@ -452,14 +452,9 @@ descr_get_qualname(PyDescrObject *descr, void *Py_UNUSED(ignored))
 static PyObject *
 descr_reduce(PyDescrObject *descr, PyObject *Py_UNUSED(ignored))
 {
-    PyObject *builtins;
-    PyObject *getattr;
     _Py_IDENTIFIER(getattr);
-
-    builtins = PyEval_GetBuiltins();
-    getattr = _PyDict_GetItemId(builtins, &PyId_getattr);
-    return Py_BuildValue("O(OO)", getattr, PyDescr_TYPE(descr),
-                         PyDescr_NAME(descr));
+    return Py_BuildValue("N(OO)", _PyEval_GetBuiltinId(&PyId_getattr),
+                         PyDescr_TYPE(descr), PyDescr_NAME(descr));
 }
 
 static PyMethodDef descr_methods[] = {
@@ -1087,13 +1082,9 @@ wrapper_repr(wrapperobject *wp)
 static PyObject *
 wrapper_reduce(wrapperobject *wp, PyObject *Py_UNUSED(ignored))
 {
-    PyObject *builtins;
-    PyObject *getattr;
     _Py_IDENTIFIER(getattr);
-
-    builtins = PyEval_GetBuiltins();
-    getattr = _PyDict_GetItemId(builtins, &PyId_getattr);
-    return Py_BuildValue("O(OO)", getattr, wp->self, PyDescr_NAME(wp->descr));
+    return Py_BuildValue("N(OO)", _PyEval_GetBuiltinId(&PyId_getattr),
+                         wp->self, PyDescr_NAME(wp->descr));
 }
 
 static PyMethodDef wrapper_methods[] = {

Objects/dictobject.c

@@ -3810,6 +3810,7 @@ dict___reversed___impl(PyDictObject *self)
 static PyObject *
 dictiter_reduce(dictiterobject *di, PyObject *Py_UNUSED(ignored))
 {
+    _Py_IDENTIFIER(iter);
     /* copy the iterator state */
     dictiterobject tmp = *di;
     Py_XINCREF(tmp.di_dict);
@@ -3819,7 +3820,7 @@ dictiter_reduce(dictiterobject *di, PyObject *Py_UNUSED(ignored))
     if (list == NULL) {
         return NULL;
     }
-    return Py_BuildValue("N(N)", _PyObject_GetBuiltin("iter"), list);
+    return Py_BuildValue("N(N)", _PyEval_GetBuiltinId(&PyId_iter), list);
 }
 
 PyTypeObject PyDictRevIterItem_Type = {

Objects/iterobject.c

@@ -104,11 +104,12 @@ PyDoc_STRVAR(length_hint_doc, "Private method returning an estimate of len(list(
 static PyObject *
 iter_reduce(seqiterobject *it, PyObject *Py_UNUSED(ignored))
 {
+    _Py_IDENTIFIER(iter);
     if (it->it_seq != NULL)
-        return Py_BuildValue("N(O)n", _PyObject_GetBuiltin("iter"),
+        return Py_BuildValue("N(O)n", _PyEval_GetBuiltinId(&PyId_iter),
                              it->it_seq, it->it_index);
     else
-        return Py_BuildValue("N(())", _PyObject_GetBuiltin("iter"));
+        return Py_BuildValue("N(())", _PyEval_GetBuiltinId(&PyId_iter));
 }
 
 PyDoc_STRVAR(reduce_doc, "Return state information for pickling.");
@@ -243,11 +244,12 @@ calliter_iternext(calliterobject *it)
 static PyObject *
 calliter_reduce(calliterobject *it, PyObject *Py_UNUSED(ignored))
 {
+    _Py_IDENTIFIER(iter);
     if (it->it_callable != NULL && it->it_sentinel != NULL)
-        return Py_BuildValue("N(OO)", _PyObject_GetBuiltin("iter"),
+        return Py_BuildValue("N(OO)", _PyEval_GetBuiltinId(&PyId_iter),
                              it->it_callable, it->it_sentinel);
     else
-        return Py_BuildValue("N(())", _PyObject_GetBuiltin("iter"));
+        return Py_BuildValue("N(())", _PyEval_GetBuiltinId(&PyId_iter));
 }
 
 static PyMethodDef calliter_methods[] = {

Objects/listobject.c

@@ -3356,23 +3356,25 @@ listreviter_setstate(listreviterobject *it, PyObject *state)
 static PyObject *
 listiter_reduce_general(void *_it, int forward)
 {
+    _Py_IDENTIFIER(iter);
+    _Py_IDENTIFIER(reversed);
     PyObject *list;
 
     /* the objects are not the same, index is of different types! */
     if (forward) {
         listiterobject *it = (listiterobject *)_it;
         if (it->it_seq)
-            return Py_BuildValue("N(O)n", _PyObject_GetBuiltin("iter"),
+            return Py_BuildValue("N(O)n", _PyEval_GetBuiltinId(&PyId_iter),
                                  it->it_seq, it->it_index);
     } else {
         listreviterobject *it = (listreviterobject *)_it;
         if (it->it_seq)
-            return Py_BuildValue("N(O)n", _PyObject_GetBuiltin("reversed"),
+            return Py_BuildValue("N(O)n", _PyEval_GetBuiltinId(&PyId_reversed),
                                  it->it_seq, it->it_index);
     }
     /* empty iterator, create an empty list */
     list = PyList_New(0);
     if (list == NULL)
         return NULL;
-    return Py_BuildValue("N(N)", _PyObject_GetBuiltin("iter"), list);
+    return Py_BuildValue("N(N)", _PyEval_GetBuiltinId(&PyId_iter), list);
 }

Objects/methodobject.c

@@ -104,16 +104,13 @@ meth_dealloc(PyCFunctionObject *m)
 static PyObject *
 meth_reduce(PyCFunctionObject *m, PyObject *Py_UNUSED(ignored))
 {
-    PyObject *builtins;
-    PyObject *getattr;
     _Py_IDENTIFIER(getattr);
 
     if (m->m_self == NULL || PyModule_Check(m->m_self))
         return PyUnicode_FromString(m->m_ml->ml_name);
 
-    builtins = PyEval_GetBuiltins();
-    getattr = _PyDict_GetItemId(builtins, &PyId_getattr);
-    return Py_BuildValue("O(Os)", getattr, m->m_self, m->m_ml->ml_name);
+    return Py_BuildValue("N(Os)", _PyEval_GetBuiltinId(&PyId_getattr),
+                         m->m_self, m->m_ml->ml_name);
 }
 
 static PyMethodDef meth_methods[] = {

Objects/object.c

@@ -1080,23 +1080,6 @@ PyObject_SelfIter(PyObject *obj)
     return obj;
 }
 
-/* Convenience function to get a builtin from its name */
-PyObject *
-_PyObject_GetBuiltin(const char *name)
-{
-    PyObject *mod_name, *mod, *attr;
-
-    mod_name = _PyUnicode_FromId(&PyId_builtins);   /* borrowed */
-    if (mod_name == NULL)
-        return NULL;
-    mod = PyImport_Import(mod_name);
-    if (mod == NULL)
-        return NULL;
-    attr = PyObject_GetAttrString(mod, name);
-    Py_DECREF(mod);
-    return attr;
-}
-
 /* Helper used when the __next__ method is removed from a type:
    tp_iternext is never NULL and can be safely called without checking
    on every iteration.

Objects/odictobject.c

@@ -1806,6 +1806,7 @@ PyDoc_STRVAR(reduce_doc, "Return state information for pickling");
 static PyObject *
 odictiter_reduce(odictiterobject *di, PyObject *Py_UNUSED(ignored))
 {
+    _Py_IDENTIFIER(iter);
     /* copy the iterator state */
     odictiterobject tmp = *di;
     Py_XINCREF(tmp.di_odict);
@@ -1818,7 +1819,7 @@ odictiter_reduce(odictiterobject *di, PyObject *Py_UNUSED(ignored))
     if (list == NULL) {
         return NULL;
     }
-    return Py_BuildValue("N(N)", _PyObject_GetBuiltin("iter"), list);
+    return Py_BuildValue("N(N)", _PyEval_GetBuiltinId(&PyId_iter), list);
 }
 
 static PyMethodDef odictiter_methods[] = {

Objects/rangeobject.c

@@ -742,6 +742,7 @@ PyDoc_STRVAR(length_hint_doc,
 static PyObject *
 rangeiter_reduce(rangeiterobject *r, PyObject *Py_UNUSED(ignored))
 {
+    _Py_IDENTIFIER(iter);
     PyObject *start=NULL, *stop=NULL, *step=NULL;
     PyObject *range;
 
@@ -760,7 +761,8 @@ rangeiter_reduce(rangeiterobject *r, PyObject *Py_UNUSED(ignored))
     if (range == NULL)
         goto err;
     /* return the result */
-    return Py_BuildValue("N(N)i", _PyObject_GetBuiltin("iter"), range, r->index);
+    return Py_BuildValue("N(N)i", _PyEval_GetBuiltinId(&PyId_iter),
+                         range, r->index);
 err:
     Py_XDECREF(start);
     Py_XDECREF(stop);
@@ -898,6 +900,7 @@ longrangeiter_len(longrangeiterobject *r, PyObject *no_args)
 static PyObject *
 longrangeiter_reduce(longrangeiterobject *r, PyObject *Py_UNUSED(ignored))
 {
+    _Py_IDENTIFIER(iter);
     PyObject *product, *stop=NULL;
     PyObject *range;
 
@@ -921,7 +924,8 @@ longrangeiter_reduce(longrangeiterobject *r, PyObject *Py_UNUSED(ignored))
     }
 
     /* return the result */
-    return Py_BuildValue("N(N)O", _PyObject_GetBuiltin("iter"), range, r->index);
+    return Py_BuildValue("N(N)O", _PyEval_GetBuiltinId(&PyId_iter),
+                         range, r->index);
 }
 
 static PyObject *

Objects/setobject.c

@@ -842,6 +842,7 @@ static PyObject *setiter_iternext(setiterobject *si);
 static PyObject *
 setiter_reduce(setiterobject *si, PyObject *Py_UNUSED(ignored))
 {
+    _Py_IDENTIFIER(iter);
     /* copy the iterator state */
     setiterobject tmp = *si;
     Py_XINCREF(tmp.si_set);
@@ -852,7 +853,7 @@ setiter_reduce(setiterobject *si, PyObject *Py_UNUSED(ignored))
     if (list == NULL) {
         return NULL;
     }
-    return Py_BuildValue("N(N)", _PyObject_GetBuiltin("iter"), list);
+    return Py_BuildValue("N(N)", _PyEval_GetBuiltinId(&PyId_iter), list);
 }
 
 PyDoc_STRVAR(reduce_doc, "Return state information for pickling.");

Objects/tupleobject.c

@@ -1024,11 +1024,12 @@ PyDoc_STRVAR(length_hint_doc, "Private method returning an estimate of len(list(
 static PyObject *
 tupleiter_reduce(tupleiterobject *it, PyObject *Py_UNUSED(ignored))
 {
+    _Py_IDENTIFIER(iter);
     if (it->it_seq)
-        return Py_BuildValue("N(O)n", _PyObject_GetBuiltin("iter"),
+        return Py_BuildValue("N(O)n", _PyEval_GetBuiltinId(&PyId_iter),
                              it->it_seq, it->it_index);
     else
-        return Py_BuildValue("N(())", _PyObject_GetBuiltin("iter"));
+        return Py_BuildValue("N(())", _PyEval_GetBuiltinId(&PyId_iter));
 }
 
 static PyObject *

Objects/unicodeobject.c

@@ -15444,14 +15444,15 @@ PyDoc_STRVAR(length_hint_doc, "Private method returning an estimate of len(list(
 static PyObject *
 unicodeiter_reduce(unicodeiterobject *it, PyObject *Py_UNUSED(ignored))
 {
+    _Py_IDENTIFIER(iter);
     if (it->it_seq != NULL) {
-        return Py_BuildValue("N(O)n", _PyObject_GetBuiltin("iter"),
+        return Py_BuildValue("N(O)n", _PyEval_GetBuiltinId(&PyId_iter),
                              it->it_seq, it->it_index);
     } else {
         PyObject *u = (PyObject *)_PyUnicode_New(0);
         if (u == NULL)
             return NULL;
-        return Py_BuildValue("N(N)", _PyObject_GetBuiltin("iter"), u);
+        return Py_BuildValue("N(N)", _PyEval_GetBuiltinId(&PyId_iter), u);
     }
 }
 

Python/ceval.c

@@ -4437,6 +4437,20 @@ PyEval_GetBuiltins(void)
         return current_frame->f_builtins;
 }
 
+/* Convenience function to get a builtin from its name */
+PyObject *
+_PyEval_GetBuiltinId(_Py_Identifier *name)
+{
+    PyObject *attr = _PyDict_GetItemIdWithError(PyEval_GetBuiltins(), name);
+    if (attr) {
+        Py_INCREF(attr);
+    }
+    else if (!PyErr_Occurred()) {
+        PyErr_SetObject(PyExc_AttributeError, _PyUnicode_FromId(name));
+    }
+    return attr;
+}
+
 PyObject *
 PyEval_GetLocals(void)
 {