bpo-42093: Cleanup _PyDict_GetItemHint()

Objects/dictobject.c

@@ -1439,11 +1439,8 @@ PyDict_GetItem(PyObject *op, PyObject *key)
 
 Py_ssize_t
 _PyDict_GetItemHint(PyDictObject *mp, PyObject *key,
-  Py_ssize_t hint, PyObject **value)
+ Py_ssize_t hint, PyObject **value)
 {
- Py_hash_t hash;
- PyThreadState *tstate;
-
  assert(*value == NULL);
  assert(PyDict_CheckExact((PyObject*)mp));
  assert(PyUnicode_CheckExact(key));
@@ -1467,39 +1464,15 @@ _PyDict_GetItemHint(PyDictObject *mp, PyObject *key,
  }
  }
 
- if ((hash = ((PyASCIIObject *) key)->hash) == -1)
- {
+ Py_hash_t hash = ((PyASCIIObject *) key)->hash;
+ if (hash == -1) {
  hash = PyObject_Hash(key);
  if (hash == -1) {
- PyErr_Clear();
- return -1;
- }
- }
-
- // We can arrive here with a NULL tstate during initialization: try
- // running "python -Wi" for an example related to string interning
- tstate = _PyThreadState_UncheckedGet();
- Py_ssize_t ix = 0;
- if (tstate != NULL && tstate->curexc_type != NULL) {
- /* preserve the existing exception */
- PyObject *err_type, *err_value, *err_tb;
- PyErr_Fetch(&err_type, &err_value, &err_tb);
- ix = (mp->ma_keys->dk_lookup)(mp, key, hash, value);
- /* ignore errors */
- PyErr_Restore(err_type, err_value, err_tb);
- if (ix < 0) {
- return -1;
- }
- }
- else {
- ix = (mp->ma_keys->dk_lookup)(mp, key, hash, value);
- if (ix < 0) {
- PyErr_Clear();
  return -1;
  }
  }
 
- return ix;
+ return (mp->ma_keys->dk_lookup)(mp, key, hash, value);
 }
 
 /* Same as PyDict_GetItemWithError() but with hash supplied by caller.

Python/ceval.c

@@ -3217,9 +3217,10 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
  Py_ssize_t hint = la->hint;
  Py_INCREF(dict);
  res = NULL;
+ assert(!_PyErr_Occurred(tstate));
  la->hint = _PyDict_GetItemHint((PyDictObject*)dict, name, hint, &res);
-
  if (res != NULL) {
+ assert(la->hint >= 0);
  if (la->hint == hint && hint >= 0) {
  // Our hint has helped -- cache hit.
  OPCACHE_STAT_ATTR_HIT();
@@ -3234,18 +3235,22 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
  Py_DECREF(owner);
  Py_DECREF(dict);
  DISPATCH();
- } else {
+ }
+ else {
+ _PyErr_Clear(tstate);
  // This attribute can be missing sometimes;
  // we don't want to optimize this lookup.
  OPCACHE_DEOPT_LOAD_ATTR();
  Py_DECREF(dict);
  }
- } else {
+ }
+ else {
  // There is no dict, or __dict__ doesn't satisfy PyDict_CheckExact.
  OPCACHE_DEOPT_LOAD_ATTR();
  }
  }
- } else {
+ }
+ else {
  // The type of the object has either been updated,
  // or is different. Maybe it will stabilize?
  OPCACHE_MAYBE_DEOPT_LOAD_ATTR();
@@ -3301,14 +3306,16 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
  }
  // Else it's some other kind of descriptor that we don't handle.
  OPCACHE_DEOPT_LOAD_ATTR();
- } else if (type->tp_dictoffset > 0) {
+ }
+ else if (type->tp_dictoffset > 0) {
  // We found an instance with a __dict__.
  dictptr = (PyObject **) ((char *)owner + type->tp_dictoffset);
  dict = *dictptr;
 
  if (dict != NULL && PyDict_CheckExact(dict)) {
  Py_INCREF(dict);
  res = NULL;
+ assert(!_PyErr_Occurred(tstate));
  Py_ssize_t hint = _PyDict_GetItemHint((PyDictObject*)dict, name, -1, &res);
  if (res != NULL) {
  Py_INCREF(res);
@@ -3325,10 +3332,14 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
  la = &co_opcache->u.la;
  la->type = type;
  la->tp_version_tag = type->tp_version_tag;
+ assert(hint >= 0);
  la->hint = hint;
 
  DISPATCH();
  }
+ else {
+ _PyErr_Clear(tstate);
+ }
  Py_DECREF(dict);
  } else {
  // There is no dict, or __dict__ doesn't satisfy PyDict_CheckExact.