Re: [PATCH v1] gdb/python: fix memory leak in gdb_py_tp_name

[Tom Tromey <tom@tromey.com>]

>>>>> "Andrew" == Andrew Burgess <aburgess@redhat.com> writes:

Andrew> isn't throwing an error here going to be problematic as gdb_py_tp_name
Andrew> is called from Python callbacks?  Unless these are catching and handling
Andrew> exceptions then the error is going to end up trying to pass through
Andrew> Python's C code.

Yeah.

I guess maybe it isn't explicitly stated anywhere (not sure) but the
rule in gdb's Python layer is that gdb exceptions can't propagate into
Python itself.  So if a function is called from Python (say like a
__repr__ implementation), then that function has to be sure that it does
not throw.  And since most things in gdb can throw, this is why at
present we wrap calls into gdb's core in try/catch.

Andrew> So maybe just returning something like "<type name unavailable>" would
Andrew> be better?  This might be better even when the safety work _is_ merged;
Andrew> if gdb_py_tp_name is called as part of logging then we'd probably rather
Andrew> log "<type name unavailable>" than have GDB throw an exception?

Yeah, I think this is what should be done, since IIUC the cases where
this can set the Python exception are pathological in nature.

Or just propagating the Python exception.  Though this would mean using
a return type other than std::string.

Tom