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From: David Rowley <dgrowleyml@gmail.com>
Date: Wed, 12 Mar 2025 19:38:50 +1300
Message-ID: 
 <CAApHDvow4CPgEyHWuSpfMQN8vRYrMgMTOqsy2SwNbQruPVV0rw@mail.gmail.com>
Subject: Re: pgsql: pg_logicalinspect: Fix possible crash when passing a
 directory p
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Masahiko Sawada <sawada.mshk@gmail.com>,
 pgsql-committers@lists.postgresql.org
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On Wed, 12 Mar 2025 at 18:18, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> I don't know of an easy way.  I experimented with doing this:
>
> diff --git a/src/include/c.h b/src/include/c.h
> index a14c6315162..467b1f58ae8 100644
> --- a/src/include/c.h
> +++ b/src/include/c.h
> @@ -315,7 +315,7 @@
>  #elif defined(_MSC_VER) && !defined(USE_ASSERT_CHECKING)
>  #define pg_unreachable() __assume(0)
>  #else
> -#define pg_unreachable() abort()
> +#define pg_unreachable() ((void) 0)
>  #endif
>
>  /*
>
> which seems like it ought to be enough to provoke such warnings
> (in assert-enabled builds).  I got upwards of sixty build warnings
> this way, but the place David mentions was *not* among them.
> So I'm confused.

Doing that for me does show the new warning.

drowley@amd7945hx:~/pg_src$ meson setup -Dcassert=3Dtrue build >
/dev/null && cd build && ninja | grep pg_logicalinspect.c
[1962/2356] Compiling C object
contrib/pg_logicalinspect/pg_logicalinspect.so.p/pg_logicalinspect.c.o
../contrib/pg_logicalinspect/pg_logicalinspect.c: In function
=E2=80=98parse_snapshot_filename=E2=80=99:
../contrib/pg_logicalinspect/pg_logicalinspect.c:88:1: warning:
control reaches end of non-void function [-Wreturn-type]
drowley@amd7945hx:~/pg_src$ gcc --version
gcc (Ubuntu 13.3.0-6ubuntu2~24.04) 13.3.0

David