binutils-gdb/gdb/python/py-obj-type.h
Matthieu Longo dafd73bcda gdb/python: fix memory leak in gdb_py_tp_name
The current implementation of gdb_py_tp_name() leaks a reference to the
object returned by PyType_GetFullyQualifiedName() for Python >= 3.13, and
PyType_GetQualName() for Python >= 3.11.

Managing the strong reference on the returned PyObject* with a gdbpy_ref<>
fixes the reference count, but also causes the temporary object to be
deallocated on function exit. As a consequence, the 'const char *' returned
by PyUnicode_AsUTF8AndSize() becomes dangling and can no longer safely be
returned.

The proposed approach consists in changing gdb_py_tp_name() to return a
std::string, and forcing a copy of the 'const char *' value, statically
or dynamically allocated, stored in a temporary or non-temporary PyObject,
depending on the version of Python it was compiled with.
An unfortunate side effect of this fix is that every call sites where the
tp_name is printed, must now use `.c_str()' because PyErr_Format()
and its siblings cannot handle std::string.

Approved-By: Andrew Burgess <aburgess@redhat.com>
2026-06-04 15:09:54 +01:00

29 lines
1.1 KiB
C++

/* Helpers related to Python object type
Copyright (C) 2026 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#ifndef GDB_PYTHON_PY_OBJ_TYPE_H
#define GDB_PYTHON_PY_OBJ_TYPE_H
/* Return the type's fully qualified name from a PyTypeObject. */
extern std::string gdb_py_tp_name (PyTypeObject *py_type) noexcept;
/* Return the type's fully qualified name from a PyObject. */
extern std::string gdbpy_py_obj_tp_name (PyObject *self) noexcept;
#endif /* GDB_PYTHON_PY_OBJ_TYPE_H */