RE: 5.8.8 make sure we get the proper ldflags on libperl.so

On Fri, 09 Mar 2007, H.Merijn Brand wrote:
> On Thu, 22 Feb 2007 14:39:02 -0800, Tom Callaway (via
RT)
> <perlbug-followupperl.org> wrote:
> > As part of the review process for Perl, I'm
opening bugs for the
> > long list of patches to perl that Fedora has been
carrying around
> > (in some cases, for years), in the hopes that
these fixes can be
> > applied upstream. Unfortunately, I am not the
original author of
> > these patches, so please be patient with me as I
attempt to describe
> > why Fedora uses them.
>
> Thanks, applied in change #30530 I hope there is
someone out there in
> the wild that uses this in smokes as I don't think the
smokes pick up
> share libperl's

This patch breaks building libperl.so for both maint and
blead on at least
Redhat 7 and 9 (it builds fine on non-legacy distros):

`uname -a` for both machines:
  Linux redhat-70-i386 2.2.24-7.0.3 #1 Fri Mar 14 08:28:25
EST 2003 i686 unknown
  Linux redhat-9-i386 2.4.20-46.9.legacy #1 Thu Mar 2
16:11:28 EST 2006 i686 i686 i386 GNU/Linux

Both machines have all available patches applied to them.

The failure is identical on both and looks like this:

gcc -o libperl.so -shared -O2  -lnsl -ldl -lm -lcrypt -lutil
-lpthread -lc   gv.o toke.o perly.o op.o pad.o regcomp.o
dump.o util.o
mg.o reentr.o hv.o av.o perl.o run.o pp_hot.o sv.o pp.o
scope.o pp_ctl.o pp_sys.o doop.o doio.o regexec.o utf8.o
taint.o deb.o
universal.o xsutils.o activeperl.o globals.o perlio.o
perlapi.o numeric.o mathoms.o locale.o pp_pack.o pp_sort.o 
DynaLoader.o -lnsl
-ldl -lm -lcrypt -lutil -lpthread -lc 
/usr/bin/ld: libperl.so: undefined versioned symbol name
_LIB_VERSIONGLIBC_2.0
/usr/bin/ld: failed to set dynamic section sizes: Bad value
collect2: ld returned 1 exit status

It is some kind of weird interaction with this change:

  http://public.activestate.com/cgi-bin/perlbrowse/p/24371


Change 24371 could be made more specific to apply only on
BSD and Cygwin, but
I think the patch in this bug report (30530) is actually not
needed at all.

> > This patch is described as "make sure we get
the proper ldflags on
> > libperl.so". Presumably, without it, the
shared object does not get
> > the proper ldflags.

This patch doesn't add anything to the gcc commandline to
build libperl.so
that isn't already there (see above).  Therefore I think the
presumption is
wrong and the patch should be reverted.

Note that this will still only be treating the symptoms. 
Gozer came up with
the following simple test program that fails to link on
Redhat 7 and 9, even
without the duplicate -lm option:

  /* cc -o libfoo.so -shared -lm foo.c */
  #include <math.h>
  _LIB_VERSION_TYPE _LIB_VERSION = _IEEE_;

This is just for reference, in case the problem with
LIB_VERSION shows
up again; libperl.so seems to build fine again for now...

Cheers,
-Jan

> > --- perl-5.8.0/Makefile.SH.sharedlinker Tue Jun 18
12:36:27 2002
> > +++ perl-5.8.0/Makefile.SH      Tue Jun 18
12:37:31 2002
> >  -61,6 +61,9 
> >         netbsd*|freebsd[234]*|openbsd*)
> >                 linklibperl="-L.
-lperl"
> >                 ;;
> > +       linux*)
> > +               shrpldflags="$shrpldflags
$ldflags $perllibs $cryptlib"
> > +               ;;
> >         aix*)
> >                 shrpldflags="-H512 -T512
-bhalt:4 -bM:SRE -bE:perl.exp"
> >                 case "$osvers" in
> >

On 29/05/07, Jan Dubois <jandactivestate.com> wrote:
> Change 24371 could be made more specific to apply only
on BSD and Cygwin, but
> I think the patch in this bug report (30530) is
actually not needed at all.

OK, I reverted it now.