[PATCH] libgcc: use linker script for libgcc_s.so on xtensa

[Baruch Siach]

The xtensa port uses __xtensa_libgcc_window_spill in libgcc to implement
__builtin_frame_address. This symbol is local/hidden in libgcc. This is not a
problem when linking against static libgcc. But g++ defaults to
-shared-libgcc, thus breaking link against C++ shared libraries that are using
__builtin_frame_address as follows:

ld: test: hidden symbol `__xtensa_libgcc_window_spill' in 
.../libgcc.a(lib2funcs.o) is referenced by DSO

Make libgcc_s.so a linker script that links in unresolved symbols from the
static libgcc, similar to the ARM and PowerPC ports.

libgcc/
        * config.host (tmake_file): add t-slibgcc-libgcc for xtensa*-*-linux*.
---
 libgcc/config.host | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libgcc/config.host b/libgcc/config.host
index 75a17e3..178f6d9 100644
--- a/libgcc/config.host
+++ b/libgcc/config.host
@@ -1181,7 +1181,7 @@ xtensa*-*-elf*)
        extra_parts="$extra_parts crti.o crtn.o"
        ;;
 xtensa*-*-linux*)
-       tmake_file="$tmake_file xtensa/t-xtensa xtensa/t-linux"
+       tmake_file="$tmake_file xtensa/t-xtensa xtensa/t-linux t-slibgcc-libgcc"
        md_unwind_header=xtensa/linux-unwind.h
        ;;
 am33_2.0-*-linux*)
-- 
1.8.5.2