Thread: Suppressing compiler warning on Debian 12/gcc 12.2.0

Being a new user of Debian 12/gcc 12.2.0, I wrote the following shell
script to conditionally add gmake rules with compiler flags to
src/Makefile.custom to suppress warnings for certain files.  This allows
me to compile all supported Postgres releases without warnings.

I actually didn't how simple it was to add per-file compile flags until
I read:

    https://stackoverflow.com/questions/6546162/how-to-add-different-rules-for-specific-files

---------------------------------------------------------------------------

# PG 14+ uses configure.ac
if [ ! -e configure.in ] || grep -q 'AC_INIT(\[PostgreSQL\], \[13\.' configure.in
then    cat >> src/Makefile.custom <<END
# work around gcc -O1 bug found in PG 13-current, not -O[023], 2023-08-28
# https://www.postgresql.org/message-id/ZOz3cBySkbEA5RN+@momjian.us
# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111240
# gmake fix:  https://stackoverflow.com/questions/6546162/how-to-add-different-rules-for-specific-files
clauses.o: CFLAGS+=-O2
END
fi

if [ -e configure.in ] && grep -q 'AC_INIT(\[PostgreSQL\], \[11\.' configure.in
then    cat >> src/Makefile.custom <<END
# new warning in Debian 12, gcc (Debian 12.2.0-14) 12.2.0, 2023-08-14
# Fix for valid macro using stack_base_ptr, warning only in PG 11
postgres.o: CFLAGS+=-Wdangling-pointer=0
END
fi

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

  Only you can decide what is important to you.

On Thu, Aug 31, 2023 at 03:25:09PM -0400, Bruce Momjian wrote:
> Being a new user of Debian 12/gcc 12.2.0, I wrote the following shell
> script to conditionally add gmake rules with compiler flags to
> src/Makefile.custom to suppress warnings for certain files.  This allows
> me to compile all supported Postgres releases without warnings.
> 
> I actually didn't how simple it was to add per-file compile flags until
> I read:
> 
>     https://stackoverflow.com/questions/6546162/how-to-add-different-rules-for-specific-files

This might be simpler for people to modify since it abstracts out the
version checking.

---------------------------------------------------------------------------

# gmake per-file options:  https://stackoverflow.com/questions/6546162/how-to-add-different-rules-for-specific-files

for FILE in configure.in configure.ac
do      if [ -e "$FILE" ]
        then    VERSION=$(sed -n 's/^AC_INIT(\[PostgreSQL\], \[\([0-9]\+\).*$/\1/p' "$FILE")
                break
        fi
done

[ -z "$VERSION" ] && echo 'Could not find Postgres version' 1>&2 && exit 1

if [ "$VERSION" -eq 11 ]
then    cat >> src/Makefile.custom <<END

# new warning in Debian 12, gcc (Debian 12.2.0-14) 12.2.0, 2023-08-14
# Fix for valid macro using stack_base_ptr
postgres.o: CFLAGS+=-Wdangling-pointer=0
END
fi

if [ "$VERSION" -ge 13 ]
then    cat >> src/Makefile.custom <<END

# work around gcc -O1 bug found in PG 13-current, not -O[023], 2023-08-28
# https://www.postgresql.org/message-id/ZOz3cBySkbEA5RN+@momjian.us
# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111240
clauses.o: CFLAGS+=-O2
END
fi

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

  Only you can decide what is important to you.