public inbox for [email protected]
help / color / mirror / Atom feedFrom: Tom Lane <[email protected]>
To: David Rowley <[email protected]>
Cc: Peter Eisentraut <[email protected]>
Cc: Masahiko Sawada <[email protected]>
Cc: [email protected]
Subject: Re: pgsql: pg_logicalinspect: Fix possible crash when passing a directory p
Date: Wed, 16 Jul 2025 10:56:20 -0400
Message-ID: <[email protected]> (raw)
In-Reply-To: <CAApHDvrFdXjbrV6KCx_GHKYSufUbNDYSsjppcJQiGOURfJE6qg@mail.gmail.com>
References: <[email protected]>
<CAApHDvqrhFfnetbcwgGkJ=z63T8HfQ_OyP=vX8BYiXyxFKt67w@mail.gmail.com>
<[email protected]>
<CAApHDvqf4tKwE0oP8ybL2Eu-SD=C34pdZ9vVDSJwvqDXi88nUg@mail.gmail.com>
<[email protected]>
<CAApHDvrFdXjbrV6KCx_GHKYSufUbNDYSsjppcJQiGOURfJE6qg@mail.gmail.com>
[ this thread was referenced recently, bringing it back top-of-mind ]
David Rowley <[email protected]> writes:
> On Thu, 13 Mar 2025 at 21:33, Peter Eisentraut <[email protected]> wrote:
>> Is there a way to reshuffle those conditionals to make this actually do
>> something useful on MSVC?
> I've just been experimenting with this and it seems the problem isn't
> with pg_unreachable(), it's with the compiler not understanding that
> the particular pg_unreachable() is always reached.
> What's happening is down to the multi-eval protection code for elevel
> in ereport_domain(). Because elevel is assigned to the variable
> "elevel_" the compiler seems to lose its proof that the
> pg_unreachable() is always reached. Adjusting that condition to use
> the elevel parameter directly makes the warning disappear.
Looking again at the code for ereport_domain(), I wondered if
something like this would help MSVC see through it:
#define ereport_domain(elevel, domain, ...) \
do { \
const int elevel_ = (elevel); \
+ const bool is_error_ = (elevel_ >= ERROR); \
pg_prevent_errno_in_scope(); \
if (errstart(elevel_, domain)) \
__VA_ARGS__, errfinish(__FILE__, __LINE__, __func__); \
- if (elevel_ >= ERROR) \
+ if (is_error_) \
pg_unreachable(); \
} while(0)
This preserves single evaluation of the elevel parameter, and
perhaps it'd move the needle on whether the compiler thinks
is_error_ is a compile-time constant. I'm just guessing
though, don't have this compiler to test with.
regards, tom lane
view thread (16+ messages) latest in thread
reply
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: [email protected]
Cc: [email protected], [email protected], [email protected], [email protected], [email protected]
Subject: Re: pgsql: pg_logicalinspect: Fix possible crash when passing a directory p
In-Reply-To: <[email protected]>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox