gh-106320: Remove _PyDict_GetItemStringWithError() function (#108313)

Remove private _PyDict_GetItemStringWithError() function of the
public C API: the new PyDict_GetItemStringRef() can be used instead.

* Move private _PyDict_GetItemStringWithError() to the internal C API.
* _testcapi get_code_extra_index() uses PyDict_GetItemStringRef().
  Avoid using private functions in _testcapi which tests the public C
  API.

Include/cpython/dictobject.h

@@ -36,7 +36,6 @@ PyAPI_FUNC(PyObject *) _PyDict_GetItem_KnownHash(PyObject *mp, PyObject *key,
                                        Py_hash_t hash);
 PyAPI_FUNC(PyObject *) _PyDict_GetItemIdWithError(PyObject *dp,
                                                   _Py_Identifier *key);
-PyAPI_FUNC(PyObject *) _PyDict_GetItemStringWithError(PyObject *, const char *);
 PyAPI_FUNC(PyObject *) PyDict_SetDefault(
     PyObject *mp, PyObject *key, PyObject *defaultobj);
 PyAPI_FUNC(int) _PyDict_SetItem_KnownHash(PyObject *mp, PyObject *key,

Include/internal/pycore_dict.h

@@ -13,6 +13,7 @@ extern "C" {
 
 // Unsafe flavor of PyDict_GetItemWithError(): no error checking
 extern PyObject* _PyDict_GetItemWithError(PyObject *dp, PyObject *key);
+extern PyObject* _PyDict_GetItemStringWithError(PyObject *, const char *);
 
 extern int _PyDict_Contains_KnownHash(PyObject *, PyObject *, Py_hash_t);
 

Modules/_testcapi/code.c

@@ -9,12 +9,12 @@ get_code_extra_index(PyInterpreterState* interp) {
     PyObject *interp_dict = PyInterpreterState_GetDict(interp); // borrowed
     assert(interp_dict);  // real users would handle missing dict... somehow
 
-    PyObject *index_obj = _PyDict_GetItemStringWithError(interp_dict, key); // borrowed
-    Py_ssize_t index = 0;
-    if (!index_obj) {
-        if (PyErr_Occurred()) {
+    PyObject *index_obj;
+    if (PyDict_GetItemStringRef(interp_dict, key, &index_obj) < 0) {
         goto finally;
     }
+    Py_ssize_t index = 0;
+    if (!index_obj) {
         index = PyUnstable_Eval_RequestCodeExtraIndex(NULL);
         if (index < 0 || PyErr_Occurred()) {
             goto finally;
@@ -31,6 +31,7 @@ get_code_extra_index(PyInterpreterState* interp) {
     }
     else {
         index = PyLong_AsSsize_t(index_obj);
+        Py_DECREF(index_obj);
         if (index == -1 && PyErr_Occurred()) {
             goto finally;
         }

Objects/structseq.c

@@ -8,6 +8,7 @@
 */
 
 #include "Python.h"
+#include "pycore_dict.h"          // _PyDict_GetItemStringWithError()
 #include "pycore_tuple.h"         // _PyTuple_FromArray()
 #include "pycore_object.h"        // _PyObject_GC_TRACK()
 

Python/codecs.c

@@ -10,6 +10,7 @@ Copyright (c) Corporation for National Research Initiatives.
 
 #include "Python.h"
 #include "pycore_call.h"          // _PyObject_CallNoArgs()
+#include "pycore_dict.h"          // _PyDict_GetItemStringWithError()
 #include "pycore_interp.h"        // PyInterpreterState.codec_search_path
 #include "pycore_pyerrors.h"      // _PyErr_FormatNote()
 #include "pycore_pystate.h"       // _PyInterpreterState_GET()

Python/import.c

@@ -1,7 +1,7 @@
 /* Module definition and import implementation */
 
 #include "Python.h"
-
+#include "pycore_dict.h"          // _PyDict_GetItemStringWithError()
 #include "pycore_hashtable.h"     // _Py_hashtable_new_full()
 #include "pycore_import.h"        // _PyImport_BootstrapImp()
 #include "pycore_initconfig.h"    // _PyStatus_OK()
@@ -15,6 +15,7 @@
 #include "pycore_pystate.h"       // _PyInterpreterState_GET()
 #include "pycore_sysmodule.h"     // _PySys_Audit()
 #include "pycore_weakref.h"       // _PyWeakref_GET_REF()
+
 #include "marshal.h"              // PyMarshal_ReadObjectFromString()
 #include "importdl.h"             // _PyImport_DynLoadFiletab
 #include "pydtrace.h"             // PyDTrace_IMPORT_FIND_LOAD_START_ENABLED()

Python/initconfig.c

@@ -1,4 +1,5 @@
 #include "Python.h"
+#include "pycore_dict.h"          // _PyDict_GetItemStringWithError()
 #include "pycore_fileutils.h"     // _Py_HasFileSystemDefaultEncodeErrors
 #include "pycore_getopt.h"        // _PyOS_GetOpt()
 #include "pycore_initconfig.h"    // _PyStatus_OK()

Python/pythonrun.c

@@ -15,6 +15,7 @@
 #include "pycore_ast.h"           // PyAST_mod2obj
 #include "pycore_ceval.h"         // _Py_EnterRecursiveCall
 #include "pycore_compile.h"       // _PyAST_Compile()
+#include "pycore_dict.h"          // _PyDict_GetItemStringWithError()
 #include "pycore_interp.h"        // PyInterpreterState.importlib
 #include "pycore_object.h"        // _PyDebug_PrintTotalRefs()
 #include "pycore_parser.h"        // _PyParser_ASTFromString()