Re: Darwin & Dynamic modules

[Christoph Pfisterer]

Max Horn wrote:
> OK, I think I  just found out that this is the reason modules are 
> not built right on darwin:
>
> # Commands used to build and install a shared archive.
> archive_cmds="\$CC \$(test \\"x\$module\\" = xyes && echo -bundle || 
> echo -dynamiclib) \$allow_undefined_flag -o \$lib \$libobjs 
> \$deplibs\$linker_flags -install_name \$rpath/\$soname \$verstring"
>
> Changing the two \\" to \" worked nicely for me. Libtool, with this 
> change, produces modules now when asked for them.

As Guido noted this is in fact an old problem and has been fixed 
before. Unfortunately, it was reintroduced into branch-1-4 and HEAD 
when my latest Darwin support patch was merged on September 2nd. The 
1.4.1 and 1.4.2 releases are affected by this. Some quotes:

Before (libtool.m4 revision 1.166.2.16):
    archive_cmds='$nonopt $(test .$module = .yes && echo -bundle || 
echo -dynami
clib) $allow_undefined_flag -o $lib $libobjs $deplibs$linker_flags 
-install_name
 $rpath/$soname $(test -n "$verstring" -a x$verstring != x0.0 && echo 
$verstring
)'

My submitted patch:
    archive_cmds='$nonopt $(test .$module = .yes && echo -bundle || echo -dynam
iclib) $allow_undefined_flag -o $lib $libobjs $deplibs$linker_flags 
-install_nam
e $rpath/$soname $verstring'

After (libtool.m4 revision 1.166.2.17):
    archive_cmds='$nonopt $(test "x$module" = xyes && echo -bundle || 
echo -dyna
miclib) $allow_undefined_flag -o $lib $libobjs $deplibs$linker_flags 
-install_na
me $rpath/$soname $verstring'

I actually explained in my mail at the time that double quotes don't 
work in archive_cmds with zsh, which forced me to move the $verstring 
handling to ltmain.sh... I guess that was a case of pre-release 
stress.


As for the convenience library issue: Gary refused the patch saying 
that it breaks the cdemo tests. It was not said on which platform, 
but I assume it was Linux. Actually, I was able to reproduce the 
failure on my Debian Linux box (potato w/ 2.4 kernel) with branch-1-4 
as of Wednesday. After reverting back to a clean copy, running 
cdemo-conf and cdemo-make in verbose mode produces these command 
lines at the end of cdemo-make (still on Linux):

  /bin/sh ./libtool --mode=link gcc  -g -O2  -o cdemo  main.o libfoo.la
  gcc -g -O2 -o cdemo main.o  ./.libs/libfoo.al -lm

As I understand it, listing a convenience library on the link command 
line is supposed to be equivalent to listing its member objects. 
'cdemo/libtool --config' shows that libtool knows the special flags 
to accheive this:

  whole_archive_flag_spec="\${wl}--whole-archive\$convenience 
\${wl}--no-whole-archive"

For some reason, this is not used in this situation. My conclusion is 
that convenience library linking is broken as it is and needs to be 
fixed. That the patch that fixes it on Darwin breaks other platforms 
is just a symptom of greater breakage.

I'll be happy to provide more information if required.

Hope this helps,
-chrisp

--
chrisp a.k.a. Christoph Pfisterer   "Any sufficiently advanced
address@hidden - http://chrisp.de      bug is indistinguishable
PGP key & geek code available        from a feature."