Re: IRIX 6.5 and exporting symbols.

[Ralf Wildenhues]

Michael -- this might be of interest for you.  Quoting generously since
the ML archives don't provide me with a link yet.

* Peter Ekberg wrote on Wed, Mar 09, 2005 at 03:14:46PM CET:
> Ralf Wildenhues wrote:
> > * Peter Ekberg wrote on Wed, Mar 09, 2005 at 02:11:40PM CET:
> >> On 2005-01-13, I wrote:
> >>> 

[ libtool -export-symbols ... on IRIX 6.5 with gcc results in: ]

> >>> gcc -v -shared .libs/cleanup.o .libs/cleanup_stubs.o .libs/cpuid.o
> >>> .libs/conf.o .libs/debug.o .libs/dl.o .libs/init.o .libs/misc.o
> >>> .libs/parse.o .libs/string.o .libs/time.o .libs/task.o
> >>> .libs/ptlock.o .libs/ptsched.o -lpthread -Wl,-soname -Wl,libgg.so.2
> >>> -Wl,-set_version 
> >>> -Wl,sgi2.0 -Wl,-update_registry -Wl,.libs/so_locations
> >>> -Wl,-exports_file
> >>> -Wl,../gg/EXPSYMS -o .libs/libgg.so.2.0
> >>> 
> >>> gets me:
> >>> 
> >>> Reading specs from
> >>> /pkg/gcc/mips-irix65/3.2/lib/gcc-lib/mips-sgi-irix6.5/3.2/specs
> >>> *snip*
> >>> /pkg/gcc/mips-irix65/3.2/lib/gcc-lib/mips-sgi-irix6.5/3.2/crtend.o
> >>> ld32: ERROR 4: Conflicting flag setting: -exports_file 
> >>> ld32: ERROR 4: Conflicting flag setting: -exports_file
> >>> collect2: ld returned 2 exit status
> >>> 
> >>> Which provides further evidence that the gcc ML message referred to
> >>> in the original post was correct. I.e. the -hidden_symbol
> >>> argument is what
> >>> conflicts with -exports_file, since -exports_file automatically
> >>> hides all symbols not mentioned and hiding a symbol twice is
> >>> apparently treated as a conflict (which is a bit mysterious).
> >> 
> >> I thought I'd provide a patch against the 2.0 branch.
> >> 
> >> It simply disables the possibility to specify which symbols
> >> you want to export, since this can't be done in a reliable
> >> way.
> > 
> > Ouch.  And does so for all gcc versions and all irix[56] versions plus
> > nonstoupx (whatever that is..).  This is definitely too broad for a
> > workaround.  This must've worked at some time in the past (with some
> > older gcc maybe?), it would not be nice to kill that for
> > possible users.
> 
> At least I got some attention :-)

Hehe. :)

> I know that it happens for gcc 2.8.1 and gcc 3.2.something.
> The gcc bug report indicates that it also happens on
> gcc 3.4.0.

After some grepping I found out that archive_expsyms_cmds has only last
year been introduced for IRIX, patch here:
http://lists.gnu.org/archive/html/libtool-patches/2004-02/msg00152.html

Michael, did you have a chance to test this with gcc back then?
If so, maybe you could provide any information on the scope of this bug.

> All instances of the bug are on mips-sgi-irix6.5 and using
> the lib32 ABI (or whatever it's called). I have no other
> IRIX platform to check for how widespread the bug is.

> >> This makes it work for me, the namespace is sadly polluted,
> >> but there is nothing we can do about that, short of hacking
> >> the gcc specs file or wait for gcc 3.5/4.0 to be released
> >> as indicated by this bugzilla entry:
> >> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15288
> > 
> > We should try to at least enable it for gcc >= 4.0, so Libtool won't
> > need to change again then.  Plus, IRIX ld may have this fixed
> > eventually; did anyone bother SGI folks about this?
> 
> I did a cursory search for gcc version tests in libtool.m4
> in order to find some code to copy, but didn't find anything.
> How would I go about testing the gcc version?

Preprocess a file with __GNUC__ (and __GNUC_MINOR__ if necessary).
Maybe we can abandon that idea in favor of just running the linker
through gcc with `-exports_file' and see whether that blows up..

> I don't know if SGI folks has been bothered.

Anyone with a support contract reading?

> > Just thinking out loud: this issue is not ABI-dependent, right?
> 
> Might be, but I don't know enough about IRIX to know how to
> test though. If someone tells me how to do it, I can check.
*snip*

Thinking out lout yet again: we could go back to linking with
$LD (shudder).  This way, we could have all the functionality..
Any volunteers?

Regards,
Ralf

> 2005-03-09  Peter Ekberg  <spam.protected>
> 
>       * m4/libtool.m4 (_LT_LINKER_SHLIBS): Don't use the
>       -exports_file linker option on irix with gcc, as
>       the default gcc specs file includes a -hidden_symbol
>       option that is clashing with the -exports_file option.
>       See this gcc bugzilla entry for further details:
>       http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15288