[PATCH] Piecewise linking with GNU ld scripts

[Paolo Bonzini]

I ported this over from GCC's custom libtool (which I hope to get rid of 
some time, since GCC has entirely switched to Autoconf 2.5x now), is it 
ok for HEAD?

I attach a 'diff -u' and a 'diff -ub' patch for ease of review.

How am I supposed to test it, apart from 'make check' which does not 
test this path?

Paolo

2004-08-23  Paolo Bonzini  <address@hidden>

        * config/ltmain.in (piecewise linking): Use a GNU ld script if
        possible.
        * m4/libtool.m4 (_LT_LINKER_SHLIBS): Add per-tag variable
        with_gnu_ld.
        (_LT_LANG_CXX_CONFIG): Don't set unused variable with_gnu_ldcxx.

? build
? config-h.in
? config/compile
? config/config.guess
? config/config.sub
? config/depcomp
? libltdl/loaders/Makefile.in
? m4/ltversion.m4
Index: config/ltmain.in
===================================================================
RCS file: /cvsroot/libtool/libtool/config/ltmain.in,v
retrieving revision 1.2
diff -u -b -r1.2 ltmain.in
--- config/ltmain.in    3 Aug 2004 14:54:34 -0000       1.2
+++ config/ltmain.in    23 Aug 2004 13:21:56 -0000
@@ -4222,8 +4222,8 @@
           test "$len" -le "$max_cmd_len" || test "$max_cmd_len" -le -1; then
          :
        else
-         # The command line is too long to link in one step, link piecewise.
-         $echo "creating reloadable object files..."
+         # The command line is too long to link in one step, link piecewise
+         # or, if using GNU ld and skipped_export is not :, use a linker script
 
          # Save the value of $output and $libobjs because we want to
          # use them later.  If we have whole_archive_flag_spec, we
@@ -4247,6 +4247,18 @@
          delfiles=
          last_robj=
          k=1
+
+         if test "X$skipped_export" != "X:" && test "$with_gnu_ld" = yes; then
+           output=${output_objdir}/${output_la}.lnk
+           $echo "creating GNU ld script: $output"
+           $echo 'INPUT (' > $output
+           for obj in $save_libobjs
+           do
+             $echo \""$obj"\" >> $output
+           done
+           $echo ')' >> $output
+         else
+           $echo "creating reloadable object files..."
          output=$output_objdir/$output_la-${k}.$objext
          # Loop over the list of objects to be linked.
          for obj in $save_libobjs
@@ -4289,7 +4301,7 @@
            eval concat_cmds=\"\$concat_cmds~$export_symbols_cmds\"
           fi
 
-         # Set up a command to remove the reloadale object files
+           # Set up a command to remove the reloadable object files
          # after they are used.
          i=0
          while test "$i" -lt "$k"
@@ -4317,6 +4329,7 @@
            }
          done
          IFS="$save_ifs"
+         fi
 
          libobjs=$output
          # Restore the value of output.
Index: m4/libtool.m4
===================================================================
RCS file: /cvsroot/libtool/libtool/m4/libtool.m4,v
retrieving revision 1.91
diff -u -b -r1.91 libtool.m4
--- m4/libtool.m4       22 Aug 2004 22:02:07 -0000      1.91
+++ m4/libtool.m4       23 Aug 2004 13:21:56 -0000
@@ -4218,6 +4218,8 @@
 AC_MSG_RESULT([$_LT_TAGVAR(ld_shlibs, $1)])
 test "$_LT_TAGVAR(ld_shlibs, $1)" = no && can_build_shared=no
 
+_LT_TAGVAR(with_gnu_ld, $1)=$with_gnu_ld
+
 _LT_DECL([], [libext], [0], [Old archive suffix (normally "a")])dnl
 _LT_DECL([], [shrext_cmds], [1], [Shared library suffix (normally ".so")])dnl
 _LT_DECL([], [extract_expsyms_cmds], [2],
@@ -4302,6 +4304,8 @@
     [Commands used to build a loadable module if different from building
     a shared archive.])
 _LT_TAGDECL([], [module_expsym_cmds], [2])
+_LT_TAGDECL([with_gnu_ld], [with_gnu_ld], [1],
+    [Whether we are using GNU ld or not])
 _LT_TAGDECL([], [allow_undefined_flag], [1],
     [Flag that allows shared libraries with undefined symbols to be built])
 _LT_TAGDECL([], [no_undefined_flag], [1],
@@ -5377,7 +5381,6 @@
 LDCXX=$LD
 LD=$lt_save_LD
 GCC=$lt_save_GCC
-with_gnu_ldcxx=$with_gnu_ld
 with_gnu_ld=$lt_save_with_gnu_ld
 lt_cv_path_LDCXX=$lt_cv_path_LD
 lt_cv_path_LD=$lt_save_path_LD

Index: config/ltmain.in
===================================================================
RCS file: /cvsroot/libtool/libtool/config/ltmain.in,v
retrieving revision 1.2
diff -u -r1.2 ltmain.in
--- config/ltmain.in    3 Aug 2004 14:54:34 -0000       1.2
+++ config/ltmain.in    23 Aug 2004 11:35:33 -0000
@@ -4222,8 +4222,8 @@
           test "$len" -le "$max_cmd_len" || test "$max_cmd_len" -le -1; then
          :
        else
-         # The command line is too long to link in one step, link piecewise.
-         $echo "creating reloadable object files..."
+         # The command line is too long to link in one step, link piecewise
+         # or, if using GNU ld and skipped_export is not :, use a linker script
 
          # Save the value of $output and $libobjs because we want to
          # use them later.  If we have whole_archive_flag_spec, we
@@ -4247,76 +4247,89 @@
          delfiles=
          last_robj=
          k=1
-         output=$output_objdir/$output_la-${k}.$objext
-         # Loop over the list of objects to be linked.
-         for obj in $save_libobjs
-         do
-           eval test_cmds=\"$reload_cmds $objlist $last_robj\"
-           if test "X$objlist" = X ||
-              { len=`expr "X$test_cmds" : ".*"` &&
-                test "$len" -le "$max_cmd_len"; }; then
-             objlist="$objlist $obj"
-           else
-             # The command $test_cmds is almost too long, add a
-             # command to the queue.
-             if test "$k" -eq 1 ; then
-               # The first file doesn't have a previous command to add.
-               eval concat_cmds=\"$reload_cmds $objlist $last_robj\"
+
+         if test "X$skipped_export" != "X:" && test "$with_gnu_ld" = yes; then
+           output=${output_objdir}/${output_la}.lnk
+           $echo "creating GNU ld script: $output"
+           $echo 'INPUT (' > $output
+           for obj in $save_libobjs
+           do
+             $echo \""$obj"\" >> $output
+           done
+           $echo ')' >> $output
+         else
+           $echo "creating reloadable object files..."
+           output=$output_objdir/$output_la-${k}.$objext
+           # Loop over the list of objects to be linked.
+           for obj in $save_libobjs
+           do
+             eval test_cmds=\"$reload_cmds $objlist $last_robj\"
+             if test "X$objlist" = X ||
+                { len=`expr "X$test_cmds" : ".*"` &&
+                  test "$len" -le "$max_cmd_len"; }; then
+               objlist="$objlist $obj"
              else
-               # All subsequent reloadable object files will link in
-               # the last one created.
-               eval concat_cmds=\"\$concat_cmds~$reload_cmds $objlist 
$last_robj\"
+               # The command $test_cmds is almost too long, add a
+               # command to the queue.
+               if test "$k" -eq 1 ; then
+                 # The first file doesn't have a previous command to add.
+                 eval concat_cmds=\"$reload_cmds $objlist $last_robj\"
+               else
+                 # All subsequent reloadable object files will link in
+                 # the last one created.
+                 eval concat_cmds=\"\$concat_cmds~$reload_cmds $objlist 
$last_robj\"
+               fi
+               last_robj=$output_objdir/$output_la-${k}.$objext
+               k=`expr $k + 1`
+               output=$output_objdir/$output_la-${k}.$objext
+               objlist=$obj
+               len=1
              fi
-             last_robj=$output_objdir/$output_la-${k}.$objext
-             k=`expr $k + 1`
-             output=$output_objdir/$output_la-${k}.$objext
-             objlist=$obj
-             len=1
-           fi
-         done
-         # Handle the remaining objects by creating one last
-         # reloadable object file.  All subsequent reloadable object
-         # files will link in the last one created.
-         test -z "$concat_cmds" || concat_cmds=$concat_cmds~
-         eval concat_cmds=\"\${concat_cmds}$reload_cmds $objlist $last_robj\"
-
-         if ${skipped_export-false}; then
-           $show "generating symbol list for \`$libname.la'"
-           export_symbols="$output_objdir/$libname.exp"
-           $run $rm $export_symbols
-           libobjs=$output
-           # Append the command to create the export file.
-           eval concat_cmds=\"\$concat_cmds~$export_symbols_cmds\"
-          fi
-
-         # Set up a command to remove the reloadale object files
-         # after they are used.
-         i=0
-         while test "$i" -lt "$k"
-         do
-           i=`expr $i + 1`
-           delfiles="$delfiles $output_objdir/$output_la-${i}.$objext"
-         done
-
-         $echo "creating a temporary reloadable object file: $output"
+           done
+           # Handle the remaining objects by creating one last
+           # reloadable object file.  All subsequent reloadable object
+           # files will link in the last one created.
+           test -z "$concat_cmds" || concat_cmds=$concat_cmds~
+           eval concat_cmds=\"\${concat_cmds}$reload_cmds $objlist $last_robj\"
+
+           if ${skipped_export-false}; then
+             $show "generating symbol list for \`$libname.la'"
+             export_symbols="$output_objdir/$libname.exp"
+             $run $rm $export_symbols
+             libobjs=$output
+             # Append the command to create the export file.
+             eval concat_cmds=\"\$concat_cmds~$export_symbols_cmds\"
+            fi
+
+           # Set up a command to remove the reloadable object files
+           # after they are used.
+           i=0
+           while test "$i" -lt "$k"
+           do
+             i=`expr $i + 1`
+             delfiles="$delfiles $output_objdir/$output_la-${i}.$objext"
+           done
 
-         # Loop through the commands generated above and execute them.
-         save_ifs="$IFS"; IFS='~'
-         for cmd in $concat_cmds; do
-           IFS="$save_ifs"
-           $show "$cmd"
-           $run eval "$cmd" || {
-             lt_exit=$?
+           $echo "creating a temporary reloadable object file: $output"
 
-             # Restore the uninstalled library and exit
-             if test "$mode" = relink; then
-               $run eval '(cd $output_objdir && $rm ${realname}T && $mv 
${realname}U $realname)'
-             fi
+           # Loop through the commands generated above and execute them.
+           save_ifs="$IFS"; IFS='~'
+           for cmd in $concat_cmds; do
+             IFS="$save_ifs"
+             $show "$cmd"
+             $run eval "$cmd" || {
+               lt_exit=$?
+
+               # Restore the uninstalled library and exit
+               if test "$mode" = relink; then
+                 $run eval '(cd $output_objdir && $rm ${realname}T && $mv 
${realname}U $realname)'
+               fi
 
-             exit $lt_exit
-           }
-         done
-         IFS="$save_ifs"
+               exit $lt_exit
+             }
+           done
+           IFS="$save_ifs"
+         fi
 
          libobjs=$output
          # Restore the value of output.
Index: m4/libtool.m4
===================================================================
RCS file: /cvsroot/libtool/libtool/m4/libtool.m4,v
retrieving revision 1.91
diff -u -r1.91 libtool.m4
--- m4/libtool.m4       22 Aug 2004 22:02:07 -0000      1.91
+++ m4/libtool.m4       23 Aug 2004 11:35:34 -0000
@@ -4218,6 +4218,8 @@
 AC_MSG_RESULT([$_LT_TAGVAR(ld_shlibs, $1)])
 test "$_LT_TAGVAR(ld_shlibs, $1)" = no && can_build_shared=no
 
+_LT_TAGVAR(with_gnu_ld, $1)=$with_gnu_ld
+
 _LT_DECL([], [libext], [0], [Old archive suffix (normally "a")])dnl
 _LT_DECL([], [shrext_cmds], [1], [Shared library suffix (normally ".so")])dnl
 _LT_DECL([], [extract_expsyms_cmds], [2],
@@ -4302,6 +4304,8 @@
     [Commands used to build a loadable module if different from building
     a shared archive.])
 _LT_TAGDECL([], [module_expsym_cmds], [2])
+_LT_TAGDECL([with_gnu_ld], [with_gnu_ld], [1],
+    [Whether we are using GNU ld or not])
 _LT_TAGDECL([], [allow_undefined_flag], [1],
     [Flag that allows shared libraries with undefined symbols to be built])
 _LT_TAGDECL([], [no_undefined_flag], [1],
@@ -5377,7 +5381,6 @@
 LDCXX=$LD
 LD=$lt_save_LD
 GCC=$lt_save_GCC
-with_gnu_ldcxx=$with_gnu_ld
 with_gnu_ld=$lt_save_with_gnu_ld
 lt_cv_path_LDCXX=$lt_cv_path_LD
 lt_cv_path_LD=$lt_save_path_LD