From: Peter Eisentraut <peter@eisentraut.org>
To: pgsql-committers@lists.postgresql.org
Subject: pgsql: Fix "inconsistent DLL linkage" warning on Windows MSVC
Date: Fri, 07 Nov 2025 09:34:54 +0000
Message-ID: <E1vHIru-005QgH-0j@gemulon.postgresql.org> (raw)
Fix "inconsistent DLL linkage" warning on Windows MSVC
This warning was disabled in meson.build (warning 4273). If you
enable it, it looks like this:
../src/backend/utils/misc/ps_status.c(27): warning C4273: '__p__environ': inconsistent dll linkage
C:\Program Files (x86)\Windows Kits\10\include\10.0.22621.0\ucrt\stdlib.h(1158): note: see previous definition of '__p__environ'
The declaration in ps_status.c was:
#if !defined(WIN32) || defined(_MSC_VER)
extern char **environ;
#endif
The declaration in the OS header file is:
_DCRTIMP char*** __cdecl __p__environ (void);
#define _environ (*__p__environ())
So it is evident that this could be problematic.
The old declaration was required by the old MSVCRT library, but we
don't support that anymore with MSVC.
To fix, disable the re-declaration in ps_status.c, and also in some
other places that use the same code pattern but didn't trigger the
warning.
Then we can also re-enable the warning (delete the disablement in
meson.build).
Reviewed-by: Bryan Green <dbryan.green@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://www.postgresql.org/message-id/flat/bf060644-47ff-441b-97cf-c685d0827757@eisentraut.org
Branch
------
master
Details
-------
https://git.postgresql.org/pg/commitdiff/a3ea5330fcf47390c8ab420bbf433a97a54505d6
Modified Files
--------------
meson.build | 1 -
src/backend/postmaster/postmaster.c | 2 +-
src/backend/utils/misc/ps_status.c | 2 +-
src/test/regress/regress.c | 2 +-
4 files changed, 3 insertions(+), 4 deletions(-)
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-committers@postgresql.org
Cc: peter@eisentraut.org, pgsql-committers@lists.postgresql.org
Subject: Re: pgsql: Fix "inconsistent DLL linkage" warning on Windows MSVC
In-Reply-To: <E1vHIru-005QgH-0j@gemulon.postgresql.org>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox