libunwind: backport patch to link against libgcc_s intead of libgcc

(From OE-Core rev: 9906f949627b64f9fc36bc129bb37c8dd84dc27c)

Signed-off-by: Jonathan Liu <net147@gmail.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-support/libunwind/libunwind-1.1/Link-libunwind-to-libgcc_s-rather-than-libgcc.patch

@@ -0,0 +1,42 @@
+From 508ca17a7be01d1cc960d9a07d0af4513948fb8d Mon Sep 17 00:00:00 2001
+From: Thierry Reding <treding@nvidia.com>
+Date: Fri, 27 Jun 2014 08:40:33 +0200
+Subject: [PATCH] Link libunwind to libgcc_s rather than libgcc
+
+For some architectures, -lgcc and -lgcc_s are not equivalent. On ARM for
+example, libgcc_s.so.1 contains some symbols needed by libunwind which
+are not present in libgcc.
+
+This causes the following link error when building the X.Org X server
+with libunwind support:
+
+	  CCLD     Xorg
+	/usr/lib/libunwind.so: undefined reference to `__aeabi_unwind_cpp_pr0'
+	/usr/lib/libunwind.so: undefined reference to `__aeabi_unwind_cpp_pr1'
+
+Linking against libgcc_s explicitly solves this problem.
+
+Upstream-Status: Backport
+
+Signed-off-by: Thierry Reding <treding@nvidia.com>
+Signed-off-by: Jonathan Liu <net147@gmail.com>
+---
+ configure.ac | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/configure.ac b/configure.ac
+index cffe19b..3beb5f2 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -258,7 +258,7 @@ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[#ifndef __INTEL_COMPILER
+ 
+ if test x$GCC = xyes -a x$intel_compiler != xyes; then
+   CFLAGS="${CFLAGS} -fexceptions -Wall -Wsign-compare"
+-  LIBCRTS="-lgcc"
++  LIBCRTS="-lgcc_s"
+ fi
+ AC_MSG_RESULT([$intel_compiler])
+ 
+-- 
+2.3.2
+

meta/recipes-support/libunwind/libunwind_1.1.bb

@@ -4,6 +4,7 @@ SRC_URI += "\
     file://Support-building-with-older-compilers.patch \
     file://AArch64-port.patch \
     file://Fix-test-case-link-failure-on-PowerPC-systems-with-Altivec.patch \
+    file://Link-libunwind-to-libgcc_s-rather-than-libgcc.patch \
 "
 
 SRC_URI[md5sum] = "fb4ea2f6fbbe45bf032cd36e586883ce"