Re: [COMMITTERS] pgsql: Add traceback information to PL/Python errors

On 07/04/11 23:01, Robert Haas wrote:
> On Wed, Apr 6, 2011 at 3:37 PM, Peter Eisentraut <peter_e@gmx.net> wrote:
>> Add traceback information to PL/Python errors
>>
>> This mimics the traceback information the Python interpreter prints
>> with exceptions.
>>
>> Jan Urbański
> 
> On my system this spits out a warning:
> 
> plpython.c: In function ‘PLy_traceback’:
> plpython.c:4487: warning: ‘s’ may be used uninitialized in this function
> plpython.c:4487: note: ‘s’ was declared here
> 
> That appears to be a live bug, unless it's guaranteed that lineno will
> always be > 0.

lineno should be > 0, unless Python is trying to tell us that the code
frame originates from before the function.

> Also, the loop test should really be written as current < lineno,
> rather than current != lineno, just in case we should manage to pass a
> lineno < 0, which with the current code would go into the tank and
> spin.

Yeah, good point.

> This part looks pretty sketchy, too:
> 
>     while (s && isspace((unsigned char) *s))
>         s++;
> 
> Perhaps we meant to test *s here.  It's hard to believe that we're
> really intending to test whether the pointer has fallen off the end of
> the address space and wrapped around to NULL.

Gah, so short a function and so many things that I managed to get wrong.

There's also this:
http://archives.postgresql.org/pgsql-hackers/2011-04/msg00334.php

Jan