[PATCH] RTEMS: Use __cxa_atexit by default for RTEMS

[Sebastian Huber]

The __cxa_atexit support is a reqirement for destructor registration of
thread-local objects.

For *-*-elf it is already enabled by default.  See comment line 810 in
"gcc/config.gcc".

Define TARGET_LIBGCC_SDATA_SECTION on PowerPC for RTEMS to ".sdata" to
place the __dso_handle.  The __dso_handle is referenced by application
code.  In case this code uses the small data section, the __dso_handle
must be there.

This patch should be committed to GCC 4.8 and 4.9.

Test results:

http://gcc.gnu.org/ml/gcc-testresults/2013-07/msg00671.html

gcc/ChangeLog
2013-07-08  Sebastian Huber  <sebastian.huber at embedded-brains.de>

	* config.gcc (*-*-rtems*): Use __cxa_atexit by default.
	* config/rs6000/rtems.h (TARGET_LIBGCC_SDATA_SECTION): Define.
---
 gcc/config.gcc            |    1 +
 gcc/config/rs6000/rtems.h |    3 +++
 2 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/gcc/config.gcc b/gcc/config.gcc
index a927964..1648dfe 100644
--- a/gcc/config.gcc
+++ b/gcc/config.gcc
@@ -734,6 +734,7 @@ case ${target} in
     yes) thread_file='rtems' ;;
   esac
   extra_options="${extra_options} rtems.opt"
+  default_use_cxa_atexit=yes
   use_gcc_stdint=wrap
   ;;
 *-*-uclinux*)
diff --git a/gcc/config/rs6000/rtems.h b/gcc/config/rs6000/rtems.h
index b910b5e..fb22be1 100644
--- a/gcc/config/rs6000/rtems.h
+++ b/gcc/config/rs6000/rtems.h
@@ -34,6 +34,9 @@
     }                                     \
   while (0)
 
+#undef TARGET_LIBGCC_SDATA_SECTION
+#define TARGET_LIBGCC_SDATA_SECTION ".sdata"
+
 #undef CPP_OS_DEFAULT_SPEC
 #define CPP_OS_DEFAULT_SPEC "%(cpp_os_rtems)"
 
-- 
1.7.7