New submission from STINNER Victor <vstin...@python.org>:
Cython generates a __Pyx_PyFunction_FastCallDict() function which calls PyEval_EvalCodeEx(). With Python 3.9, it worked well. With Python 3.10 in debug mode, it fails with an assertion error: python3.10: Python/ceval.c:5148: PyEval_EvalCodeEx: Assertion `(((PyCodeObject *)_co)->co_flags & (CO_NEWLOCALS | CO_OPTIMIZED)) == 0' failed. With Python 3.10 in release mode, it does crash. Context of the failed assertion: * Assertion added recently to CPython 3.10 by python/cpython@0332e56 * The code object flags = (CO_NEWLOCALS | CO_OPTIMIZED | CO_NOFREE) * Code co_argcount = 2 * Code co_kwonlyargcount = 0 * Cython __Pyx_PyFunction_FastCallDict() called with: nargs=1 and kwargs=NULL See the Cython issue to a reproducer: https://github.com/cython/cython/issues/4025#issuecomment-801829541 In Python 3.9, _PyFunction_Vectorcall() has the following fast-path: if (co->co_kwonlyargcount == 0 && nkwargs == 0 && (co->co_flags & ~PyCF_MASK) == (CO_OPTIMIZED | CO_NEWLOCALS | CO_NOFREE)) { if (argdefs == NULL && co->co_argcount == nargs) { return function_code_fastcall(tstate, co, stack, nargs, globals); } else if (nargs == 0 && argdefs != NULL && co->co_argcount == PyTuple_GET_SIZE(argdefs)) { /* function called with no arguments, but all parameters have a default value: use default values as arguments .*/ stack = _PyTuple_ITEMS(argdefs); return function_code_fastcall(tstate, co, stack, PyTuple_GET_SIZE(argdefs), globals); } } When the bug occurs, __Pyx_PyFunction_FastCallDict() doesn't take the fast-path because nargs < co_argcount (1 < 2). In Python 3.10, _PyFunction_Vectorcall() is very different: if (((PyCodeObject *)f->fc_code)->co_flags & CO_OPTIMIZED) { return _PyEval_Vector(tstate, f, NULL, stack, nargs, kwnames); } else { return _PyEval_Vector(tstate, f, f->fc_globals, stack, nargs, kwnames); } PyEval_EvalCodeEx() must not crash if the code object has (CO_NEWLOCALS | CO_OPTIMIZED | CO_NOFREE) flags. ---------- components: C API messages: 389009 nosy: Mark.Shannon, pablogsal, vstinner priority: normal severity: normal status: open title: PyEval_EvalCodeEx() can no longer be called with code which has (CO_NEWLOCALS | CO_OPTIMIZED) flags versions: Python 3.10 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue43541> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
