Horton

Re: Consistently use the XLogRecPtrIsInvalid() macro

Bertrand Drouvot <bertranddrouvot.pg@gmail.com>

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From: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
To: Álvaro Herrera <alvherre@kurilemu.de>
Cc: Peter Eisentraut <peter@eisentraut.org>, Michael Paquier <michael@paquier.xyz>, Heikki Linnakangas <hlinnaka@iki.fi>, Quan Zongliang <quanzongliang@yeah.net>, pgsql-hackers@lists.postgresql.org
Date: 2025-11-13T14:11:08Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Replace literal 0 with InvalidXLogRecPtr for XLogRecPtr assignments

  2. Replace pointer comparisons and assignments to literal zero with NULL

  3. Use XLogRecPtrIsValid() in various places

  4. Introduce XLogRecPtrIsValid()

On Fri, Nov 07, 2025 at 02:37:32PM +0100, Álvaro Herrera wrote:

> Hmm, I tried to recreate your patch using this .cocci file, and in my
> run, there's a few changes in your patch that my spatch run didn't
> detect.  I wonder if that's because my spatch version is buggy, or
> because you hacked the .cocci file beyond what's in your github repo.

spatch needs to be run with --recursive-includes (so that the .cocci script
is able to collect information from all the structs of interest). The header
comment in the .cocci script did not mention that: just fixed).

But then I realized that if I run spatch that way:

spatch --sp-file replace_literal_0_assignement_with_InvalidXLogRecPtr.cocci \
      --dir /path/to/postgres/src \
      -I /path/to/postgres/src/include \
      --recursive-includes \
      > replace.patch

Then some headers were not included (no clue as to why). But if I run spatch on
the .c files one by one with the --recursive-includes then it works (i.e all
the headers of interest are included).

So, I created [1] to run spatch one by one on all the .c files (in parallel).

To produce the patch that I shared I ran:

./run_parallel.sh /absolute_path_to/replace_literal_0_assignement_with_InvalidXLogRecPtr.cocci -j 32

(patch can be found in /path/to/postgres once completed).

> (I'm wondering if I should reproduce your previous patches in case there
> were also differences there.  Life is short though.)

I guess/hope you'll get the same results if you use run_parallel.sh as mentioned
above.

[1]: https://github.com/bdrouvot/coccinelle_on_pg/blob/main/wrappers/run_parallel.sh

Regards,

-- 
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
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