Richard Guenther <rguent...@suse.de> writes:
> On Fri, 18 Mar 2011, Rainer Orth wrote:
>
>> Richard Guenther <richard.guent...@gmail.com> writes:
>>
>> > It seemed to have disabled linker-plugin support for old binutils
>> > with --with-plugin-ld=/usr/local/bin/gold, explicit -fuse-linker-plugin
>> > says
>> > it is not supported. The system linker does not have plugin support
>> > (nor gold). /usr/local has gold from binutils 2.20.50.xxx. So it seems
>> > that
>> >
>> > # Allow -fuse-linker-plugin to enable plugin support in GNU gold 2.20.
>> > elif test "$ld_is_gold" = yes -a "$ld_vers_major" -eq 2 -a
>> > "$ld_vers_minor" -eq 20; then
>> > gcc_cv_lto_plugin=1
>> > fi
>> >
>> > only allows explicit -fuse-linker-plugin for recent gold but based on
>> > checking
>> > the system linker version (instead of that of --with-plugin-ld). I'd say
>> > allow explicit -fuse-linker-plugin always if --with-plugin-ld is specified.
>>
>> Agreed. I'll have a look and refrain from installing on 4.6 until this
>> is resolved. I wasn't even aware of --with-plugin-ld, which isn't
>> documented in install.texi ;-( This stuff seems insanely complicated to
>> me, though: which user is supposed to deal with such complications?
>
> It's sort of historic ... with plugin support for GNU ld we can probably
> drop this flag for 4.7 (eventually I'd even like to enforce the use
> of the plugin all the time or disable LTO, just for the sake of reducing
> the testing and bugreporting matrix ...).
>
> I just noticed the above with the LTO setup of our SPEC testers
> which are using somewhat old system tools.
Here's the patch I came up with. It is on top of the previous one, so
if we want to backport to 4.6 later, both are necessary.
It also fixes a typo in the in_tree_ld case, which can never have worked.
Tested by i386-pc-solaris2.11 bootstraps with either Sun ld or gld 2.21,
and by configuring with Sun ld --with-plugin-ld=gld-2.21 and obvserving
HAVE_LTO_PLUGIN being set to 1.
Ok for mainline now and 4.6 after some soak time?
Thanks.
Rainer
2011-03-19 Rainer Orth <r...@cebitec.uni-bielefeld.de>
* configure.ac (gcc_cv_lto_plugin): Fix typo.
Allow -fuse-linker-plugin for non-default plugin linker.
* configure: Regenerate.
diff -r 916a52719d80 gcc/configure.ac
--- a/gcc/configure.ac Sat Mar 19 08:54:19 2011 +0100
+++ b/gcc/configure.ac Sun Mar 20 13:37:38 2011 +0100
@@ -3192,14 +3192,14 @@
AC_MSG_CHECKING(linker plugin support)
gcc_cv_lto_plugin=0
if test -f liblto_plugin.la; then
- if test $in_tree_ld = yes -a x"$ORIGINAL_PLUGIN_LD_FOR_TARGET=" =
x"$gcc_cv_ld"; then
+ if test $in_tree_ld = yes -a x"$ORIGINAL_PLUGIN_LD_FOR_TARGET" =
x"$gcc_cv_ld"; then
if test "$gcc_cv_gld_major_version" -eq 2 -a "$gcc_cv_gld_minor_version"
-ge 21 -o "$gcc_cv_gld_major_version" -gt 2; then
gcc_cv_lto_plugin=2
elif test "$ld_is_gold" = yes -a "$gcc_cv_gld_major_version" -eq 2 -a
"$gcc_cv_gld_minor_version" -eq 20; then
gcc_cv_lto_plugin=1
fi
- elif echo "$ld_ver" | grep GNU > /dev/null; then
+ elif test x"$ORIGINAL_PLUGIN_LD_FOR_TARGET" = x"$gcc_cv_ld" && echo
"$ld_ver" | grep GNU > /dev/null; then
# Require GNU ld or gold 2.21+ for plugin support by default.
if test "$ld_vers_major" -eq 2 -a "$ld_vers_minor" -ge 21; then
gcc_cv_lto_plugin=2
@@ -3207,6 +3207,10 @@
elif test "$ld_is_gold" = yes -a "$ld_vers_major" -eq 2 -a
"$ld_vers_minor" -eq 20; then
gcc_cv_lto_plugin=1
fi
+ elif test x"$ORIGINAL_PLUGIN_LD_FOR_TARGET" != x"$gcc_cv_ld"; then
+ # Allow -fuse-linker-plugin if plugin linker differs from
+ # default/specified linker.
+ gcc_cv_lto_plugin=1
fi
fi
AC_DEFINE_UNQUOTED(HAVE_LTO_PLUGIN, $gcc_cv_lto_plugin,
--
-----------------------------------------------------------------------------
Rainer Orth, Center for Biotechnology, Bielefeld University
