Eliminate hardcode_libdir_flag_spec_ld tag variable. (was: [OMPI devel] "make check" (libtool) failure on Linux/ppc w/ XLC (1.5rc5 and 1.4.3rc1))

[Ralf Wildenhues]

[ moving to the libtool-patches list from here:
  http://www.open-mpi.org/community/lists/devel/2010/08/8399.php ]

* Ralf Wildenhues wrote on Thu, Oct 14, 2010 at 08:56:19PM CEST:
> this bug has been addressed in upstream Libtool commit
> v2.2.6-59-gb7dbec6:
> <http://git.savannah.gnu.org/cgit/libtool.git/commit/?id=v2.2.6-59-gb7dbec6>
> 
> It is not wholly fixed yet, but for all cases interesting to OpenMPI.
> (A libtoolized package using only Fortran but no C compiler may still
> have issues.)

Not totally true; since C will be enabled by libtool anyway, we are
fairly safe here (as the test will be run with the C compiler then, and
not rerun with Fortran due to caching).

However, we should fix setting hardcode_libdir_flag_spec for XL Fortran
on GNU/Linux anyway, and for that we need to ensure $wl is unset in the
shared library creation code in ltmain.  The patch below does that and
eliminates the need for hardcode_libdir_flag_spec_ld in the process.
This should also help when hardcoding flags in programs created by this
compiler.

The idea is that, if $archive_cmds contains the string `$LD ' literally,
then we are going to link with ld, and $wl can be nullified.

Warning 1: this also nullifies $wl for all following tag variable
expansions in the ltmain code.  I *think* this is safe, as by this time
all we're going to do is create a shared library; but I'm not 100% sure.
(OTOH, the number of systems where $LD is used for linking is pretty low
in practice by now.)

Warning 2: we might be creating the library with either one of
  archive_cmds
  archive_expsym_cmds
  module_cmds
  module_expsym_cmds

but the code only checks the former, rather the one that really will be
selected later.  Should I fix that, for future-proofness in case we ever
have the case where module creation differs from archive creation in
whether $LD is used directly for linking?  (Sounds fairly remote,
right?)

Tested on GNU/Linux/ppc with the XL compiler suite, as well as on
HP-UX 10.20 (no regressions in the latter).

OK to commit and add Paul to THANKS?

Thanks,
Ralf

    Eliminate hardcode_libdir_flag_spec_ld tag variable.
    
    * libltdl/config/ltmain.m4sh (func_mode_link): Set $wl to empty
    if $LD is used for creating shared libraries.  Do not use
    hardcode_libdir_flag_spec_ld any more.
    * libltdl/m4/libtool.m4 (_LT_LINKER_SHLIBS, _LT_LANG_CXX_CONFIG)
    (_LT_LANG_F77_CONFIG, _LT_LANG_FC_CONFIG, _LT_SYS_DYNAMIC_LINKER)
    <hardcode_libdir_flag_spec_ld>: Remove all instances of the tag
    variable.
    (_LT_LINKER_SHLIBS) [linux, xlf] <hardcode_libdir_flag_spec>:
    Set variable, including ${wl}.  Fixes hardcoding in programs
    created by XL Fortran on GNU/Linux.
    * NEWS, THANKS: Update.
    Report by Paul H. Hargrove.

diff --git a/NEWS b/NEWS
index d8d692e..9c12714 100644
--- a/NEWS
+++ b/NEWS
@@ -9,6 +9,15 @@ New in 2.4.2 2010-12-??: git version 2.4.1a, Libtool team:
   - The bug that leaked developer tool paths into the release tarballs
     from ./bootstrap is fixed.
 
+* Important incompatible changes:
+
+  - The undocumented hardcode_libdir_flag_spec_ld tag variable has been
+    removed in favor of using hardcode_libdir_flag_spec with $wl set to empty.
+
+* Changes in supported systems or compilers:
+
+  - Fixes for gfortran on Darwin, XL Fortran on GNU/Linux.
+
 New in 2.4 2010-09-22: git version 2.2.11a, Libtool team:
 
 * New features:
diff --git a/libltdl/config/ltmain.m4sh b/libltdl/config/ltmain.m4sh
index af46cb8..aff8a1c 100644
--- a/libltdl/config/ltmain.m4sh
+++ b/libltdl/config/ltmain.m4sh
@@ -7237,6 +7237,11 @@ EOF
 
       # Test again, we may have decided not to build it any more
       if test "$build_libtool_libs" = yes; then
+       # Remove ${wl} instances when linking with ld.
+       # FIXME: should test the right _cmds variable.
+       case $archive_cmds in
+         *\$LD\ *) wl= ;;
+        esac
        if test "$hardcode_into_libs" = yes; then
          # Hardcode the library paths
          hardcode_libdirs=
@@ -7275,11 +7280,7 @@ EOF
          if test -n "$hardcode_libdir_separator" &&
             test -n "$hardcode_libdirs"; then
            libdir="$hardcode_libdirs"
-           if test -n "$hardcode_libdir_flag_spec_ld"; then
-             eval dep_rpath=\"$hardcode_libdir_flag_spec_ld\"
-           else
-             eval dep_rpath=\"$hardcode_libdir_flag_spec\"
-           fi
+           eval "dep_rpath=\"$hardcode_libdir_flag_spec\""
          fi
          if test -n "$runpath_var" && test -n "$perm_rpath"; then
            # We should set the runpath_var.
diff --git a/libltdl/m4/libtool.m4 b/libltdl/m4/libtool.m4
index d8b3a4d..419ffe1 100644
--- a/libltdl/m4/libtool.m4
+++ b/libltdl/m4/libtool.m4
@@ -4522,7 +4522,6 @@ m4_if([$1], [CXX], [
   _LT_TAGVAR(hardcode_direct, $1)=no
   _LT_TAGVAR(hardcode_direct_absolute, $1)=no
   _LT_TAGVAR(hardcode_libdir_flag_spec, $1)=
-  _LT_TAGVAR(hardcode_libdir_flag_spec_ld, $1)=
   _LT_TAGVAR(hardcode_libdir_separator, $1)=
   _LT_TAGVAR(hardcode_minus_L, $1)=no
   _LT_TAGVAR(hardcode_shlibpath_var, $1)=unsupported
@@ -4773,8 +4772,7 @@ _LT_EOF
        xlf* | bgf* | bgxlf* | mpixlf*)
          # IBM XL Fortran 10.1 on PPC cannot create shared libs itself
          _LT_TAGVAR(whole_archive_flag_spec, $1)='--whole-archive$convenience 
--no-whole-archive'
-         _LT_TAGVAR(hardcode_libdir_flag_spec, $1)=
-         _LT_TAGVAR(hardcode_libdir_flag_spec_ld, $1)='-rpath $libdir'
+         _LT_TAGVAR(hardcode_libdir_flag_spec, $1)='${wl}-rpath ${wl}$libdir'
          _LT_TAGVAR(archive_cmds, $1)='$LD -shared $libobjs $deplibs 
$linker_flags -soname $soname -o $lib'
          if test "x$supports_anon_versioning" = xyes; then
            _LT_TAGVAR(archive_expsym_cmds, $1)='echo "{ global:" > 
$output_objdir/$libname.ver~
@@ -5171,7 +5169,6 @@ _LT_EOF
       fi
       if test "$with_gnu_ld" = no; then
        _LT_TAGVAR(hardcode_libdir_flag_spec, $1)='${wl}+b ${wl}$libdir'
-       _LT_TAGVAR(hardcode_libdir_flag_spec_ld, $1)='+b $libdir'
        _LT_TAGVAR(hardcode_libdir_separator, $1)=:
        _LT_TAGVAR(hardcode_direct, $1)=yes
        _LT_TAGVAR(hardcode_direct_absolute, $1)=yes
@@ -5613,9 +5610,6 @@ _LT_TAGDECL([], [no_undefined_flag], [1],
 _LT_TAGDECL([], [hardcode_libdir_flag_spec], [1],
     [Flag to hardcode $libdir into a binary during linking.
     This must work even if $libdir does not exist])
-_LT_TAGDECL([], [hardcode_libdir_flag_spec_ld], [1],
-    [[If ld is used when linking, flag to hardcode $libdir into a binary
-    during linking.  This must work even if $libdir does not exist]])
 _LT_TAGDECL([], [hardcode_libdir_separator], [1],
     [Whether we need a single "-rpath" flag with a separated argument])
 _LT_TAGDECL([], [hardcode_direct], [0],
@@ -5773,7 +5767,6 @@ _LT_TAGVAR(export_dynamic_flag_spec, $1)=
 _LT_TAGVAR(hardcode_direct, $1)=no
 _LT_TAGVAR(hardcode_direct_absolute, $1)=no
 _LT_TAGVAR(hardcode_libdir_flag_spec, $1)=
-_LT_TAGVAR(hardcode_libdir_flag_spec_ld, $1)=
 _LT_TAGVAR(hardcode_libdir_separator, $1)=
 _LT_TAGVAR(hardcode_minus_L, $1)=no
 _LT_TAGVAR(hardcode_shlibpath_var, $1)=unsupported
@@ -7106,7 +7099,6 @@ _LT_TAGVAR(export_dynamic_flag_spec, $1)=
 _LT_TAGVAR(hardcode_direct, $1)=no
 _LT_TAGVAR(hardcode_direct_absolute, $1)=no
 _LT_TAGVAR(hardcode_libdir_flag_spec, $1)=
-_LT_TAGVAR(hardcode_libdir_flag_spec_ld, $1)=
 _LT_TAGVAR(hardcode_libdir_separator, $1)=
 _LT_TAGVAR(hardcode_minus_L, $1)=no
 _LT_TAGVAR(hardcode_automatic, $1)=no
@@ -7239,7 +7231,6 @@ _LT_TAGVAR(export_dynamic_flag_spec, $1)=
 _LT_TAGVAR(hardcode_direct, $1)=no
 _LT_TAGVAR(hardcode_direct_absolute, $1)=no
 _LT_TAGVAR(hardcode_libdir_flag_spec, $1)=
-_LT_TAGVAR(hardcode_libdir_flag_spec_ld, $1)=
 _LT_TAGVAR(hardcode_libdir_separator, $1)=
 _LT_TAGVAR(hardcode_minus_L, $1)=no
 _LT_TAGVAR(hardcode_automatic, $1)=no