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Message-ID: <4f87171d-1623-4acf-8d7e-80a714ae68ea@eisentraut.org>
Date: Thu, 15 Aug 2024 09:50:15 +0200
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Subject: Re: format_datum debugging function
To: Paul Jungwirth <pj@illuminatedcomputing.com>,
 Aleksander Alekseev <aleksander@timescale.com>,
 PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
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 <463c034f-a1bb-4361-ada7-83e994d86bfb@illuminatedcomputing.com>
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 <991fd3e7-f414-4320-8674-e9651ece1b4e@illuminatedcomputing.com>
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From: Peter Eisentraut <peter@eisentraut.org>
In-Reply-To: <991fd3e7-f414-4320-8674-e9651ece1b4e@illuminatedcomputing.com>
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On 14.08.24 17:46, Paul Jungwirth wrote:
> On 8/14/24 02:16, Peter Eisentraut wrote:
>> On 12.08.24 23:15, Paul Jungwirth wrote:
>>> On 8/12/24 04:32, Aleksander Alekseev wrote:
>>>>> [...] This function takes a Datum and the appropriate out function, 
>>>>> and returns a char *. So you
>>>>> can do this:
>>>>>
>>>>> (gdb) call format_datum(range_out, $1)
>>>>> $2 = 0x59162692d938 "[1,4)"
>>>>>
>>>>> I assume a patch like this doesn't need documentation. Does it need 
>>>>> a test? Anything else?
>>>>
>>>> I think you forgot to attach the patch. Or is it just a proposal?
>>>
>>> Sorry, patch attached here.
>>
>> I don't think it's safe to call output functions at arbitrary points 
>> from a debugger.  But if you're okay with that during development, 
>> say, then I think you could just call 
>> OidOutputFunctionCall(F_RANGE_OUT, $1)?
> 
> I assumed it wasn't safe everywhere (e.g. there is potentially a TOAST 
> lookup), but for debugging a patch that's okay with me.
> 
> Are you doing something to get macro expansion? I've never gotten my gdb 
> to see #defines, although in theory this configure line should do it, 
> right?:

Oh I see, you don't have the F_* constants available then.  Maybe just 
put in the OID manually then?