[Buildroot] [PATCH 1/1] package/gcc: ensure __register_frame is optimized out for glibc

[James Hilliard]

On some architectures when building with -O0 the __register_frame
symbol fails to get optimized out which can cause linking failures
when building glibc.

To fix this set -O1 for GCC target libs when building with glibc
and BR2_OPTIMIZE_0 on the problematic target architectures.

Fixes:
 - http://autobuild.buildroot.net/results/89b/89b6c6924240b7cf82035a844f3573673e91b364
 - http://autobuild.buildroot.net/results/46f/46f4ec99d2b23d354a4bb5e92123d64f0da6ed27
 - http://autobuild.buildroot.net/results/839/839f929f700cf181ebdf34389c7806a96f55813e
 - http://autobuild.buildroot.net/results/0e2/0e202bf53a683930f3cad6edef2a4dea629eaecb
 - http://autobuild.buildroot.net/results/8a8/8a8c917f597fdcca744e696e19e9300b64004335
 - http://autobuild.buildroot.net/results/c05/c058b27ed2834dfa633b63ec6c3639ab1e8bf412
 - http://autobuild.buildroot.net/results/8ba/8ba8882a861cf7df359c23969c09b2be0725b2e5

Signed-off-by: James Hilliard <james.hilliard1 at gmail.com>
---
 package/gcc/gcc.mk | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/package/gcc/gcc.mk b/package/gcc/gcc.mk
index ec6f3b550a..a339f77970 100644
--- a/package/gcc/gcc.mk
+++ b/package/gcc/gcc.mk
@@ -103,6 +103,15 @@ GCC_COMMON_TARGET_CFLAGS += -matomic
 GCC_COMMON_TARGET_CXXFLAGS += -matomic
 endif
 
+# Enable GCC target libs optimizations to optimize out __register_frame
+# when needed for some architectures when building with glibc.
+ifeq ($(BR2_TOOLCHAIN_USES_GLIBC)$(BR2_OPTIMIZE_0),yy)
+ifeq ($(BR2_microblazebe)$(BR2_microblazeel)$(BR2_mips)$(BR2_mipsel)$(BR2_nios2)$(BR2_or1k)$(BR2_sh),y)
+GCC_COMMON_TARGET_CFLAGS += -O1
+GCC_COMMON_TARGET_CXXFLAGS += -O1
+endif
+endif
+
 # Propagate options used for target software building to GCC target libs
 HOST_GCC_COMMON_CONF_ENV += CFLAGS_FOR_TARGET="$(GCC_COMMON_TARGET_CFLAGS)"
 HOST_GCC_COMMON_CONF_ENV += CXXFLAGS_FOR_TARGET="$(GCC_COMMON_TARGET_CXXFLAGS)"
-- 
2.34.1