Stowage/cpython
2
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-10-31 13:41:24 +00:00
Code Issues Projects Releases Packages Wiki Activity

Correction for issue1265 (pdb bug with "with" statement).

Browse source 
When an unfinished generator-iterator is garbage collected, PyEval_EvalFrameEx
is called with a GeneratorExit exception set.  This leads to funny results
if the sys.settrace function itself makes use of generators.
A visible effect is that the settrace function is reset to None.
Another is that the eventual "finally" block of the generator is not called.

It is necessary to save/restore the exception around the call to the trace
function.

This happens a lot with py3k: isinstance() of an ABCMeta instance runs
    def __instancecheck__(cls, instance):
        """Override for isinstance(instance, cls)."""
        return any(cls.__subclasscheck__(c)
                   for c in {instance.__class__, type(instance)})
which lets an opened generator expression each time it returns True.

Seems a backport candidate, even if the case is less frequent in 2.5.
This commit is contained in:
Amaury Forgeot d'Arc 2007-11-13 01:05:30 +00:00
parent 8161a65cd8
commit f05149a257
2 changed files with 59 additions and 9 deletions
Download patch file Download diff file Expand all files Collapse all files

19
Python/ceval.c
View file

@ -107,7 +107,7 @@ static int prtrace(PyObject *, char *);
#endif
static int call_trace(Py_tracefunc, PyObject *, PyFrameObject *,
int, PyObject *);
static void call_trace_protected(Py_tracefunc, PyObject *,
static int call_trace_protected(Py_tracefunc, PyObject *,
PyFrameObject *, int, PyObject *);
static void call_exc_trace(Py_tracefunc, PyObject *, PyFrameObject *);
static int maybe_call_line_trace(Py_tracefunc, PyObject *,
@ -717,8 +717,9 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
an argument which depends on the situation.
The global trace function is also called
whenever an exception is detected. */
if (call_trace(tstate->c_tracefunc, tstate->c_traceobj,
f, PyTrace_CALL, Py_None)) {
if (call_trace_protected(tstate->c_tracefunc,
tstate->c_traceobj,
f, PyTrace_CALL, Py_None)) {
/* Trace function raised an error */
goto exit_eval_frame;
}
@ -726,9 +727,9 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
if (tstate->c_profilefunc != NULL) {
/* Similar for c_profilefunc, except it needn't
return itself and isn't called for "line" events */
if (call_trace(tstate->c_profilefunc,
tstate->c_profileobj,
f, PyTrace_CALL, Py_None)) {
if (call_trace_protected(tstate->c_profilefunc,
tstate->c_profileobj,
f, PyTrace_CALL, Py_None)) {
/* Profile function raised an error */
goto exit_eval_frame;
}
@ -3127,7 +3128,7 @@ call_exc_trace(Py_tracefunc func, PyObject *self, PyFrameObject *f)
}
}
static void
static int
call_trace_protected(Py_tracefunc func, PyObject *obj, PyFrameObject *frame,
int what, PyObject *arg)
{
@ -3136,11 +3137,15 @@ call_trace_protected(Py_tracefunc func, PyObject *obj, PyFrameObject *frame,
PyErr_Fetch(&type, &value, &traceback);
err = call_trace(func, obj, frame, what, arg);
if (err == 0)
{
PyErr_Restore(type, value, traceback);
return 0;
}
else {
Py_XDECREF(type);
Py_XDECREF(value);
Py_XDECREF(traceback);
return -1;
}
}