gh-105340: include hidden fast-locals in locals() (#105715)

* gh-105340: include hidden fast-locals in locals()

Objects/frameobject.c

@@ -1200,15 +1200,28 @@ frame_get_var(_PyInterpreterFrame *frame, PyCodeObject *co, int i,
     return 1;
 }
 
-int
-_PyFrame_FastToLocalsWithError(_PyInterpreterFrame *frame)
+
+PyObject *
+_PyFrame_GetLocals(_PyInterpreterFrame *frame, int include_hidden)
 {
     /* Merge fast locals into f->f_locals */
     PyObject *locals = frame->f_locals;
     if (locals == NULL) {
         locals = frame->f_locals = PyDict_New();
         if (locals == NULL) {
-            return -1;
+            return NULL;
+        }
+    }
+    PyObject *hidden = NULL;
+
+    /* If include_hidden, "hidden" fast locals (from inlined comprehensions in
+       module/class scopes) will be included in the returned dict, but not in
+       frame->f_locals; the returned dict will be a modified copy. Non-hidden
+       locals will still be updated in frame->f_locals. */
+    if (include_hidden) {
+        hidden = PyDict_New();
+        if (hidden == NULL) {
+            return NULL;
         }
     }
 
@@ -1224,6 +1237,11 @@ _PyFrame_FastToLocalsWithError(_PyInterpreterFrame *frame)
         PyObject *name = PyTuple_GET_ITEM(co->co_localsplusnames, i);
         _PyLocals_Kind kind = _PyLocals_GetKind(co->co_localspluskinds, i);
         if (kind & CO_FAST_HIDDEN) {
+            if (include_hidden && value != NULL) {
+                if (PyObject_SetItem(hidden, name, value) != 0) {
+                    goto error;
+                }
+            }
             continue;
         }
         if (value == NULL) {
@@ -1232,16 +1250,53 @@ _PyFrame_FastToLocalsWithError(_PyInterpreterFrame *frame)
                     PyErr_Clear();
                 }
                 else {
-                    return -1;
+                    goto error;
                 }
             }
         }
         else {
             if (PyObject_SetItem(locals, name, value) != 0) {
-                return -1;
+                goto error;
             }
         }
     }
+
+    if (include_hidden && PyDict_Size(hidden)) {
+        PyObject *innerlocals = PyDict_New();
+        if (innerlocals == NULL) {
+            goto error;
+        }
+        if (PyDict_Merge(innerlocals, locals, 1) != 0) {
+            Py_DECREF(innerlocals);
+            goto error;
+        }
+        if (PyDict_Merge(innerlocals, hidden, 1) != 0) {
+            Py_DECREF(innerlocals);
+            goto error;
+        }
+        locals = innerlocals;
+    }
+    else {
+        Py_INCREF(locals);
+    }
+    Py_CLEAR(hidden);
+
+    return locals;
+
+  error:
+    Py_XDECREF(hidden);
+    return NULL;
+}
+
+
+int
+_PyFrame_FastToLocalsWithError(_PyInterpreterFrame *frame)
+{
+    PyObject *locals = _PyFrame_GetLocals(frame, 0);
+    if (locals == NULL) {
+        return -1;
+    }
+    Py_DECREF(locals);
     return 0;
 }
 

Objects/object.c

@@ -1690,13 +1690,15 @@ _dir_locals(void)
     PyObject *names;
     PyObject *locals;
 
-    locals = PyEval_GetLocals();
+    locals = _PyEval_GetFrameLocals();
     if (locals == NULL)
         return NULL;
 
     names = PyMapping_Keys(locals);
-    if (!names)
+    Py_DECREF(locals);
+    if (!names) {
         return NULL;
+    }
     if (!PyList_Check(names)) {
         PyErr_Format(PyExc_TypeError,
             "dir(): expected keys() of locals to be a list, "
@@ -1708,7 +1710,6 @@ _dir_locals(void)
         Py_DECREF(names);
         return NULL;
     }
-    /* the locals don't need to be DECREF'd */
     return names;
 }