Message-ID: <1c197f2d-49a2-4830-8dde-55867218b62d@vondra.me>
Date: Wed, 8 Apr 2026 12:20:53 +0200
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User-Agent: Mozilla Thunderbird
Subject: Re: Adding REPACK [concurrently]
To: Alvaro Herrera <alvherre@alvh.no-ip.org>, vignesh C <vignesh21@gmail.com>
Cc: Antonin Houska <ah@cybertec.at>,
 Srinath Reddy Sadipiralla <srinath2133@gmail.com>,
 Amit Kapila <amit.kapila16@gmail.com>,
 Mihail Nikalayeu <mihailnikalayeu@gmail.com>,
 Matthias van de Meent <boekewurm+postgres@gmail.com>,
 Pg Hackers <pgsql-hackers@lists.postgresql.org>,
 Robert Treat <rob@xzilla.net>
References: <202604060918.qw5ms7cbr2hz@alvherre.pgsql>
Content-Language: en-US
From: Tomas Vondra <tomas@vondra.me>
In-Reply-To: <202604060918.qw5ms7cbr2hz@alvherre.pgsql>
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 <https://www.postgresql.org/message-id/1c197f2d-49a2-4830-8dde-55867218b62d%40vondra.me>
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Hi,

while building on a rpi5 with a 32-bit system, I'm getting these warnings:

config.status: linking src/makefiles/Makefile.linux to src/Makefile.port
In file included from ../../../src/include/access/tupmacs.h:20,
                 from ../../../src/include/access/htup_details.h:20,
                 from ../../../src/include/access/relscan.h:17,
                 from ../../../src/include/access/heapam.h:19,
                 from repack.c:36:
In function ‘VARSIZE_ANY’,
    inlined from ‘restore_tuple’ at repack.c:2731:15:
../../../src/include/varatt.h:243:51: warning: array subscript
‘varattrib_4b[0]’ is partly outside array bounds of ‘union
<anonymous>[1]’ [-Warray-bounds=]
  243 |         ((((const varattrib_4b *) (PTR))->va_4byte.va_header >>
2) & 0x3FFFFFFF)
      |           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~
../../../src/include/varatt.h:467:24: note: in expansion of macro
‘VARSIZE_4B’
  467 |                 return VARSIZE_4B(PTR);
      |                        ^~~~~~~~~~
repack.c: In function ‘restore_tuple’:
repack.c:2717:49: note: object ‘chunk_header’ of size 4
 2717 |                         }                       chunk_header;
      |                                                 ^~~~~~~~~~~~
In function ‘VARSIZE_ANY’,
    inlined from ‘restore_tuple’ at repack.c:2734:4:
../../../src/include/varatt.h:243:51: warning: array subscript
‘varattrib_4b[0]’ is partly outside array bounds of ‘union
<anonymous>[1]’ [-Warray-bounds=]
  243 |         ((((const varattrib_4b *) (PTR))->va_4byte.va_header >>
2) & 0x3FFFFFFF)
      |           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~
../../../src/include/varatt.h:467:24: note: in expansion of macro
‘VARSIZE_4B’
  467 |                 return VARSIZE_4B(PTR);
      |                        ^~~~~~~~~~
repack.c: In function ‘restore_tuple’:
repack.c:2717:49: note: object ‘chunk_header’ of size 4
 2717 |                         }                       chunk_header;
      |                                                 ^~~~~~~~~~~~

I'm not sure if it's just the compiler (gcc 14.2) being pesky, or if
it's an actual issue. The repack tests seem to pass fine.

regards

-- 
Tomas Vondra