Mercurial > cpython-lru_cache-weakref
diff Python/ceval.c @ 43846:d5fc6e96091f 2.5
Backport for issue1265 (pdb bug with "with" statement).
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.
And the problem can be reproduced in 2.5 with pure python code.
| author | Amaury Forgeot d'Arc <amauryfa@gmail.com> |
|---|---|
| date | Tue, 13 Nov 2007 22:43:05 +0000 |
| parents | 5623e233e9cc |
| children | fdd74bdeee15 |
line wrap: on
line diff
--- a/Python/ceval.c Tue Nov 13 05:23:21 2007 +0000 +++ b/Python/ceval.c Tue Nov 13 22:43:05 2007 +0000 @@ -105,7 +105,7 @@ #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 *, @@ -710,8 +710,9 @@ 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; } @@ -719,9 +720,9 @@ 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; } @@ -3192,7 +3193,7 @@ } } -static void +static int call_trace_protected(Py_tracefunc func, PyObject *obj, PyFrameObject *frame, int what, PyObject *arg) { @@ -3201,11 +3202,15 @@ 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; } }
