Re: [PATCH 1/3] libga68: honour a preset A68FLAGS

Hello Trevor.

Thanks for the patch.
I just installed it on your behalf.

> AC_PROG_A68 declares A68FLAGS as a user variable with AC_ARG_VAR, which
> promises that a value from the environment or the configure command line
> is used, and then assigns it unconditionally nine lines later. Any value
> the user supplied is discarded, so there is no way to control the flags
> the Algol 68 compiles in libga68 are built with.
>
> This matters when libga68 is built for a target whose objects have to be
> reproducible: the sources compiled by ga68 receive A68FLAGS rather than
> CFLAGS, so options such as -ffile-prefix-map never reach them and the
> build directory is recorded in the debug information.
>
> Default the variable only when it is unset, which is what libphobos
> already does for GDCFLAGS in its own configure.ac:
>
>     if test -z "$GDCFLAGS"; then
>         GDCFLAGS="-g -O2"
>     fi
>
> Assisted by: Codex (Claude Opus 5)
>
> libga68/ChangeLog:
>
> 	* m4/autoconf.m4 (AC_PROG_A68): Only default A68FLAGS when it
> 	is unset.
> 	* configure: Regenerate.
>
> Signed-off-by: Trevor Woerner <[email protected]>
> ---
>  libga68/configure      | 4 +++-
>  libga68/m4/autoconf.m4 | 4 +++-
>  2 files changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/libga68/configure b/libga68/configure
> index 731476fc9095..1208c3fa616d 100755
> --- a/libga68/configure
> +++ b/libga68/configure
> @@ -5906,7 +5906,9 @@ $as_echo "$ac_try_echo"; } >&5
>    rm -f conftest.er1 conftest.err
>    $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
>    test $ac_status = 0; }
> -A68FLAGS="-g -O2"
> +if test -z "$A68FLAGS"; then
> +  A68FLAGS="-g -O2"
> +fi
>  ac_ext=c
>  ac_cpp='$CPP $CPPFLAGS'
>  ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
> diff --git a/libga68/m4/autoconf.m4 b/libga68/m4/autoconf.m4
> index 7b85996265c0..daf67322f35e 100644
> --- a/libga68/m4/autoconf.m4
> +++ b/libga68/m4/autoconf.m4
> @@ -126,6 +126,8 @@ ac_compiler=$[2]
>  _AC_DO_LIMIT([$ac_compiler --version >&AS_MESSAGE_LOG_FD])
>  m4_expand_once([_AC_COMPILER_EXEEXT])[]dnl
>  m4_expand_once([_AC_COMPILER_OBJEXT])[]dnl
> -A68FLAGS="-g -O2"
> +if test -z "$A68FLAGS"; then
> +  A68FLAGS="-g -O2"
> +fi
>  AC_LANG_POP(Algol 68)dnl
>  ])# AC_PROG_A68