Re: request for more descriptive plperl error messages

I've been maintaining a database that contains a very large number of
plperl functions. An error in one of these functions will produce a
message such as:

ERROR: error from Perl function: syntax error at or near "." at line 58.

This is helpful to a degree but the critical missing information is the
function name (schema name would be nice too). With the current behavior
have to guess at what function might be causing this problem and then
look up the line number and see if that makes sense. I then repeat this
for the other functions until I get lucky.

Looking at src/pl/plperl/plperl.c I've found the following code:
/* XXX need to find a way to assign an errcode here */
ereport(ERROR,
(errmsg("error from Perl function: %s",
strip_trailing_ws(SvPV(ERRSV, PL_na)))));

This is duplicated in plperl_call_perl_func() and
plperl_call_perl_trigger_func()

I'd like to modify the code to return the perl function name and submit
a patch but I've never developed in the postgres code base before and am
not sure where to start. Can the function and schema name be found in
the FunctionCallInfo structure that is passed? Is this an easy thing to
do or a hard thing to do? Would anyone else find it useful? Does anyone
else want to do it?

thanks!
Robert

Am Mittwoch, 3. Oktober 2007 schrieb Robert Kleemann:
> ERROR:  error from Perl function: syntax error at or near "." at line 58.
>
> This is helpful to a degree but the critical missing information is the
> function name (schema name would be nice too).

You need to increase the error verbosity in psql, by running

\set VERBOSITY verbose

--
Peter Eisentraut
http://developer.postgresql.org/~petere/

Peter Eisentraut <peter_e(at)gmx(dot)net> writes:
> Am Mittwoch, 3. Oktober 2007 schrieb Robert Kleemann:
>> ERROR: error from Perl function: syntax error at or near "." at line 58.
>>
>> This is helpful to a degree but the critical missing information is the
>> function name (schema name would be nice too).

> You need to increase the error verbosity in psql, by running
> \set VERBOSITY verbose

Doesn't seem like that's going to provide the info he wants, namely the
name of the plperl function that's being executed.

regards, tom lane

Tom's right. \set VERBOSITY versbose gives me:

ERROR: XX000: error from Perl function: syntax error at or near "." at
line 58.
LOCATION: plperl_call_perl_func, plperl.c:1076

but doesn't give the name of the plperl function.

Robert.

Robert Kleemann <kleemann(at)scharp(dot)org> writes:
> I'd like to modify the code to return the perl function name and submit
> a patch but I've never developed in the postgres code base before and am
> not sure where to start. Can the function and schema name be found in
> the FunctionCallInfo structure that is passed?

No. The easiest thing to do is save it in the plperl_proc_desc struct.
See
http://archives.postgresql.org/pgsql-committers/2007-10/msg00117.php

regards, tom lane

Thanks for the fix Tom. You're awesome!

I assume the fix won't be in the official pg until 8.3 right? I'll need
to patch my local installation.

Robert.