From: Tom Lane <tgl@sss.pgh.pa.us>
To: Bruce Momjian <bruce@momjian.us>
cc: John Naylor <john.naylor@enterprisedb.com>,
        David Rowley <dgrowleyml@gmail.com>,
        PostgreSQL-development <pgsql-hackers@postgresql.org>
Subject: Re: Debian 12 gcc warning
In-reply-to: <ZO6u1hySX4lBI/31@momjian.us>
References: <ZOz3cBySkbEA5RN+@momjian.us> <CAApHDvosmrsBB=vJDEwxsAJhdrLXvT-JTPOHw3DG+ERv0w-M7Q@mail.gmail.com> <CAFBsxsFbNiq-S9VyBmon7J43q_pkSBgyCqWnhwj=Get51jfcAA@mail.gmail.com> <ZO3yO5qiW9A82zo4@momjian.us> <1006857.1693318716@sss.pgh.pa.us> <ZO6u1hySX4lBI/31@momjian.us>
Comments: In-reply-to Bruce Momjian <bruce@momjian.us>
	message dated "Tue, 29 Aug 2023 22:52:06 -0400"
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Date: Tue, 29 Aug 2023 23:30:06 -0400
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Bruce Momjian <bruce@momjian.us> writes:
> On Tue, Aug 29, 2023 at 10:18:36AM -0400, Tom Lane wrote:
>> That seems like a pretty clear compiler bug, particularly since it just
>> appears in this one version.  Rather than contorting our code, I'd
>> suggest filing a gcc bug.

> I assume I have to create a test case to report this to the gcc team.  I
> tried to create such a test case on gcc 12 but it doesn't generate the
> warning.  Attached is my attempt.  Any ideas?  I assume we can't just
> tell them to download our software and compile it.

IIRC, they'll accept preprocessed compiler input for the specific file;
you don't need to provide a complete source tree.  Per
https://gcc.gnu.org/bugs/

    Please include all of the following items, the first three of which ca=
n be obtained from the output of gcc -v:

    the exact version of GCC;
    the system type;
    the options given when GCC was configured/built;
    the complete command line that triggers the bug;
    the compiler output (error messages, warnings, etc.); and
    the preprocessed file (*.i*) that triggers the bug, generated by addin=
g -save-temps to the complete compilation command, or, in the case of a bu=
g report for the GNAT front end, a complete set of source files (see below=
).

Obviously, if you can trim the input it's good, but it doesn't
have to be a minimal reproducer.

			regards, tom lane