[Bug go/64900] gotools don't link on Solaris 11/x86

["ro at CeBiTec dot Uni-Bielefeld.DE" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64900

--- Comment #2 from ro at CeBiTec dot Uni-Bielefeld.DE <ro at CeBiTec dot Uni-Bielefeld.DE> ---
> --- Comment #1 from Ian Lance Taylor <ian at airs dot com> ---
> Normally libgo.so will get the symbol _Unwind_GetLanguageSpecificData from
> libgcc_s.so.  The first step here is to find out why that didn't happen.  Was
> libgo.so not linked against libgcc_s.so?  Does libgcc_s.so not define

It wasn't: it turns out that Solaris 11/SPARC and x86 differ in their
libgcc spec (sparc vs. x86):

 *libgcc:
-%{static|static-libgcc:-lgcc
-lgcc_eh}%{!static:%{!static-libgcc:%{!shared:%{!s
hared-libgcc:-lgcc -lgcc_eh}%{shared-libgcc:-lgcc_s
-lgcc}}%{shared:%{shared-lib
gcc:-lgcc_s}%{!shared-libgcc:-lgcc}}}}
+%{static|static-libgcc:-lgcc
-lgcc_eh}%{!static:%{!static-libgcc:%{!shared-libg
cc:-lgcc --as-needed -lgcc_s --no-as-needed}%{shared-libgcc:-lgcc_s%{!shared:
-l
gcc}}}}

On x86, --as-needed support in gld was disabled due to binutils PR
ld/12320 (cf. gcc/configure.ac), thus libgcc_s is only linked with
-shared when explicitly specifying -shared-libgcc.

> _Unwind_GetLanguageSpecificData?

It does.

The following patch allowed me to correctly link libgo.so with
libgcc_s.so, and as expected, gotools also link without problems:

diff --git a/libgo/Makefile.am b/libgo/Makefile.am
--- a/libgo/Makefile.am
+++ b/libgo/Makefile.am
@@ -1991,7 +1991,8 @@ libgo_go_objs = \
     unicode/utf8.lo

 libgo_ldflags = \
-    -version-info $(libtool_VERSION) $(PTHREAD_CFLAGS) $(AM_LDFLAGS)
+    -version-info $(libtool_VERSION) -Wc,-shared-libgcc \
+    $(PTHREAD_CFLAGS) $(AM_LDFLAGS)

 libgo_libadd = \
     $(libgo_go_objs) ../libbacktrace/libbacktrace.la \

    Rainer