Re: Clobbered parameter names via DECLARE in PL/PgSQL

2012/4/15 Brendan Jurd <direvus(at)gmail(dot)com>:
> On 15 April 2012 18:54, Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> wrote:
>> 2012/4/15 Brendan Jurd <direvus(at)gmail(dot)com>:
>>> Perhaps it's a failure of imagination on my part, but I can't think of
>>> a legitimate reason for a programmer to deliberately use the same name
>>> to refer to a declared variable and a function parameter.  What would
>>> be the benefit?
>>
>> it depends on level of nesting blocks. For simple functions there
>> parameter redeclaration is clean bug, but for more nested blocks and
>> complex procedures, there should be interesting using some local
>> variables with same identifier like some parameters and blocking
>> parameter's identifier can be same unfriendly feature like RO
>> parameters in previous pg versions.
>>
>> I understand your motivation well, but solution should be warning, not
>> blocking. I think.
>
> I can accept that ... but I wonder about the implementation of such a
> warning.  Can we raise a WARNING message on CREATE [OR REPLACE]
> FUNCTION?  If so, should there be a way to switch it off?  If so,
> would this be implemented globally, or per-function?  Would it be a
> postgres run-time setting, or an extension to CREATE FUNCTION syntax,
> or something within the PL/pgSQL code (like Perl's 'use strict')?

We can raise warning from CREATE OR REPLACE FUNCTION - but I would to
like have plpgsql_check_function inside core - and it is better place
for this and similar issues.

Now we talk about features in 9.3, and there check_function should be.

Regards

Pavel

>
> Cheers,
> BJ