Re: [PATCH] Build AIX shared libraries with binutils 2.19.50+

[Ralf Wildenhues]

Hello Richard,

sorry for the long delay.  Apparently the 4.3.3 system has flaky
hardware; anyway I don't trust its results any more.

I've now pushed your two proposed patches, added a small NEWS entry to
the first, and added you to THANKS.

Thanks again!
Ralf

2009-06-06  Richard Sandiford  <address@hidden>

        Build AIX shared libraries with binutils 2.19.50+.
        * libltdl/m4/libtool.m4 (_LT_LINKER_SHLIBS, _LT_LANG_CXX_CONFIG)
        <lt_use_gnu_ld_interface>: New variable to control whether the
        GNU ld or native ld interface is used.  Set to "no" for GNU ld
        2.19.50+ on AIX, otherwise mirror $with_gnu_ld.  Update the
        warning message that is printed when using GNU ld on AIX.
        Adjust the whole_archive_flag_spec value for GNU ld on AIX.
        * NEWS, THANKS: Update.

diff --git a/NEWS b/NEWS
index 42d3c69..3656acd 100644
--- a/NEWS
+++ b/NEWS
@@ -20,6 +20,7 @@ New in 2.2.8 2009-??-??: git version 2.2.7a, Libtool team:
   - Support for GNU/kOpenSolaris (kopensolaris*-gnu).
   - Initial support for compilers on BlueGene BG/L.
   - Improved support for Atari FreeMiNT.
+  - With binutils 2.19.50+, shared libraries can be built on AIX.
 
 * Bug fixes:
 
diff --git a/libltdl/m4/libtool.m4 b/libltdl/m4/libtool.m4
index 3596384..21db0b0 100644
--- a/libltdl/m4/libtool.m4
+++ b/libltdl/m4/libtool.m4
@@ -4208,7 +4208,33 @@ dnl Note also adjust exclude_expsyms for C++ above.
   esac
 
   _LT_TAGVAR(ld_shlibs, $1)=yes
+
+  # On some targets, GNU ld is compatible enough with the native linker
+  # that we're better off using the native interface for both.
+  lt_use_gnu_ld_interface=no
   if test "$with_gnu_ld" = yes; then
+    case $host_os in
+      aix*)
+       # The AIX port of GNU ld has always aspired to compatibility
+       # with the native linker.  However, as the warning in the GNU ld
+       # block says, versions before 2.19.5* couldn't really create working
+       # shared libraries, regardless of the interface used.
+       case `$LD -v 2>&1` in
+         *\ \(GNU\ Binutils\)\ 2.19.5*) ;;
+         *\ \(GNU\ Binutils\)\ 2.[[2-9]]*) ;;
+         *\ \(GNU\ Binutils\)\ [[3-9]]*) ;;
+         *)
+           lt_use_gnu_ld_interface=yes
+           ;;
+       esac
+       ;;
+      *)
+       lt_use_gnu_ld_interface=yes
+       ;;
+    esac
+  fi
+
+  if test "$lt_use_gnu_ld_interface" = yes; then
     # If archive_cmds runs LD, not CC, wlarc should be empty
     wlarc='${wl}'
 
@@ -4241,11 +4267,12 @@ dnl Note also adjust exclude_expsyms for C++ above.
        _LT_TAGVAR(ld_shlibs, $1)=no
        cat <<_LT_EOF 1>&2
 
-*** Warning: the GNU linker, at least up to release 2.9.1, is reported
+*** Warning: the GNU linker, at least up to release 2.19, is reported
 *** to be unable to reliably create shared libraries on AIX.
 *** Therefore, libtool is disabling shared libraries support.  If you
-*** really care for shared libraries, you may want to modify your PATH
-*** so that a non-GNU linker is found, and then restart.
+*** really care for shared libraries, you may want to install binutils
+*** 2.20 or above, or modify your PATH so that a non-GNU linker is found.
+*** You will then need to restart the configuration process.
 
 _LT_EOF
       fi
@@ -4605,8 +4632,13 @@ _LT_EOF
          # -berok will link without error, but may produce a broken library.
          _LT_TAGVAR(no_undefined_flag, $1)=' ${wl}-bernotok'
          _LT_TAGVAR(allow_undefined_flag, $1)=' ${wl}-berok'
-         # Exported symbols can be pulled into shared objects from archives
-         _LT_TAGVAR(whole_archive_flag_spec, $1)='$convenience'
+         if test "$with_gnu_ld" = yes; then
+           # We only use this code for GNU lds that support --whole-archive.
+           _LT_TAGVAR(whole_archive_flag_spec, 
$1)='${wl}--whole-archive$convenience ${wl}--no-whole-archive'
+         else
+           # Exported symbols can be pulled into shared objects from archives
+           _LT_TAGVAR(whole_archive_flag_spec, $1)='$convenience'
+         fi
          _LT_TAGVAR(archive_cmds_need_lc, $1)=yes
          # This is similar to how AIX traditionally builds its shared 
libraries.
          _LT_TAGVAR(archive_expsym_cmds, $1)="\$CC $shared_flag"' -o 
$output_objdir/$soname $libobjs $deplibs ${wl}-bnoentry $compiler_flags 
${wl}-bE:$export_symbols${allow_undefined_flag}~$AR $AR_FLAGS 
$output_objdir/$libname$release.a $output_objdir/$soname'
@@ -5546,8 +5578,13 @@ if test "$_lt_caught_CXX_error" != yes; then
            # -berok will link without error, but may produce a broken library.
            _LT_TAGVAR(no_undefined_flag, $1)=' ${wl}-bernotok'
            _LT_TAGVAR(allow_undefined_flag, $1)=' ${wl}-berok'
-           # Exported symbols can be pulled into shared objects from archives
-           _LT_TAGVAR(whole_archive_flag_spec, $1)='$convenience'
+           if test "$with_gnu_ld" = yes; then
+             # We only use this code for GNU lds that support --whole-archive.
+             _LT_TAGVAR(whole_archive_flag_spec, 
$1)='${wl}--whole-archive$convenience ${wl}--no-whole-archive'
+           else
+             # Exported symbols can be pulled into shared objects from archives
+             _LT_TAGVAR(whole_archive_flag_spec, $1)='$convenience'
+           fi
            _LT_TAGVAR(archive_cmds_need_lc, $1)=yes
            # This is similar to how AIX traditionally builds its shared
            # libraries.



2009-06-06  Richard Sandiford  <address@hidden>

        Fix GNU nm invocation for AIX.
        * libldtl/m4/libtool.m4 (_LT_LINKER_SHLIBS)
        <export_symbols_cmds>: Modify the GNU-nm-on-AIX version so that
        it adds weak defined symbols to the export list.

diff --git a/libltdl/m4/libtool.m4 b/libltdl/m4/libtool.m4
index 21db0b0..a7d9bf5 100644
--- a/libltdl/m4/libtool.m4
+++ b/libltdl/m4/libtool.m4
@@ -4129,8 +4129,10 @@ m4_if([$1], [CXX], [
   aix[[4-9]]*)
     # If we're using GNU nm, then we don't want the "-C" option.
     # -C means demangle to AIX nm, but means don't demangle with GNU nm
+    # Also, AIX nm treats weak defined symbols like other global defined
+    # symbols, whereas GNU nm marks them as "W".
     if $NM -V 2>&1 | $GREP 'GNU' > /dev/null; then
-      _LT_TAGVAR(export_symbols_cmds, $1)='$NM -Bpg $libobjs $convenience | 
awk '\''{ if (((\$ 2 == "T") || (\$ 2 == "D") || (\$ 2 == "B")) && ([substr](\$ 
3,1,1) != ".")) { print \$ 3 } }'\'' | sort -u > $export_symbols'
+      _LT_TAGVAR(export_symbols_cmds, $1)='$NM -Bpg $libobjs $convenience | 
awk '\''{ if (((\$ 2 == "T") || (\$ 2 == "D") || (\$ 2 == "B") || (\$ 2 == 
"W")) && ([substr](\$ 3,1,1) != ".")) { print \$ 3 } }'\'' | sort -u > 
$export_symbols'
     else
       _LT_TAGVAR(export_symbols_cmds, $1)='$NM -BCpg $libobjs $convenience | 
awk '\''{ if (((\$ 2 == "T") || (\$ 2 == "D") || (\$ 2 == "B")) && ([substr](\$ 
3,1,1) != ".")) { print \$ 3 } }'\'' | sort -u > $export_symbols'
     fi
@@ -4527,8 +4529,10 @@ _LT_EOF
       else
        # If we're using GNU nm, then we don't want the "-C" option.
        # -C means demangle to AIX nm, but means don't demangle with GNU nm
+       # Also, AIX nm treats weak defined symbols like other global
+       # defined symbols, whereas GNU nm marks them as "W".
        if $NM -V 2>&1 | $GREP 'GNU' > /dev/null; then
-         _LT_TAGVAR(export_symbols_cmds, $1)='$NM -Bpg $libobjs $convenience | 
awk '\''{ if (((\$ 2 == "T") || (\$ 2 == "D") || (\$ 2 == "B")) && ([substr](\$ 
3,1,1) != ".")) { print \$ 3 } }'\'' | sort -u > $export_symbols'
+         _LT_TAGVAR(export_symbols_cmds, $1)='$NM -Bpg $libobjs $convenience | 
awk '\''{ if (((\$ 2 == "T") || (\$ 2 == "D") || (\$ 2 == "B") || (\$ 2 == 
"W")) && ([substr](\$ 3,1,1) != ".")) { print \$ 3 } }'\'' | sort -u > 
$export_symbols'
        else
          _LT_TAGVAR(export_symbols_cmds, $1)='$NM -BCpg $libobjs $convenience 
| awk '\''{ if (((\$ 2 == "T") || (\$ 2 == "D") || (\$ 2 == "B")) && 
([substr](\$ 3,1,1) != ".")) { print \$ 3 } }'\'' | sort -u > $export_symbols'
        fi