[PATCH, COMMITTED] [AArch64] Provide symbol version for _mcount.

[Marcus Shawcroft <marcus.shawcroft@linaro.org>]

Hi, Revised following Joseph's comments and committed.
Thanks
/Marcus

---
 ports/ChangeLog.aarch64                            |  7 +++++
 ports/sysdeps/aarch64/Versions                     |  5 ++++
 ports/sysdeps/aarch64/machine-gmon.h               | 35 ++++++++++++++++++++++
 ports/sysdeps/aarch64/mcount.c                     | 33 ++++++++++++++++++++
 .../unix/sysv/linux/aarch64/nptl/libc.abilist      |  1 +
 5 files changed, 81 insertions(+)
 create mode 100644 ports/sysdeps/aarch64/Versions
 create mode 100644 ports/sysdeps/aarch64/machine-gmon.h
 create mode 100644 ports/sysdeps/aarch64/mcount.c

diff --git a/ports/ChangeLog.aarch64 b/ports/ChangeLog.aarch64
index 3f26cb7..537ae60 100644
--- a/ports/ChangeLog.aarch64
+++ b/ports/ChangeLog.aarch64
@@ -1,3 +1,10 @@
+2013-07-26  Marcus Shawcroft  <marcus.shawcroft@linaro.org>
+
+	* sysdeps/aarch64/Versions: New file.
+	* sysdeps/aarch64/machine-gmon.h: New file.
+	* sysdeps/aarch64/mcount.c: New file.
+	* sysdeps/unix/sysv/linux/aarch64/nptl/libc.abilist (_mcount): Add.
+
 2013-07-12  Marcus Shawcroft  <marcus.shawcroft@linaro.org>
 
 	* sysdeps/aarch64/Makefile (CFLAGS-backtrace.c): Define.
diff --git a/ports/sysdeps/aarch64/Versions b/ports/sysdeps/aarch64/Versions
new file mode 100644
index 0000000..e1aa44f
--- /dev/null
+++ b/ports/sysdeps/aarch64/Versions
@@ -0,0 +1,5 @@
+libc {
+  GLIBC_2.18 {
+    _mcount;
+  }
+}
diff --git a/ports/sysdeps/aarch64/machine-gmon.h b/ports/sysdeps/aarch64/machine-gmon.h
new file mode 100644
index 0000000..4425965
--- /dev/null
+++ b/ports/sysdeps/aarch64/machine-gmon.h
@@ -0,0 +1,35 @@
+/* AArch64 definitions for profiling support.
+   Copyright (C) 1996-2013 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* GCC version 2 gives us a perfect magical function to get
+   just the information we need:
+     void *__builtin_return_address (unsigned int N)
+   returns the return address of the frame N frames up.  */
+
+#include <sysdep.h>
+
+static void mcount_internal (u_long frompc, u_long selfpc);
+
+#define _MCOUNT_DECL(frompc, selfpc) \
+static inline void mcount_internal (u_long frompc, u_long selfpc)
+
+#define MCOUNT \
+void __mcount (void)							      \
+{									      \
+  mcount_internal ((u_long) RETURN_ADDRESS (1), (u_long) RETURN_ADDRESS (0)); \
+}
diff --git a/ports/sysdeps/aarch64/mcount.c b/ports/sysdeps/aarch64/mcount.c
new file mode 100644
index 0000000..10171b7
--- /dev/null
+++ b/ports/sysdeps/aarch64/mcount.c
@@ -0,0 +1,33 @@
+/* Copyright (C) 2013 Free Software Foundation, Inc.
+
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <shlib-compat.h>
+
+#include <gmon/mcount.c>
+
+/* We forgot to add _mcount in glibc 2.17.  We added it in 2.18
+   therefore we want it to be added with version GLIBC_2_18.  However,
+   setting the version is not straight forward because a generic
+   Version file includes an earlier 2.xx version for each this symbol
+   and the linker uses the first version it sees.  */
+
+#if SHLIB_COMPAT (libc, GLIBC_2_17, GLIBC_2_18)
+versioned_symbol (libc, __mcount, _mcount, GLIBC_2_18);
+#else
+strong_alias (__mcount, _mcount);
+#endif
diff --git a/ports/sysdeps/unix/sysv/linux/aarch64/nptl/libc.abilist b/ports/sysdeps/unix/sysv/linux/aarch64/nptl/libc.abilist
index b04a761..aeee312 100644
--- a/ports/sysdeps/unix/sysv/linux/aarch64/nptl/libc.abilist
+++ b/ports/sysdeps/unix/sysv/linux/aarch64/nptl/libc.abilist
@@ -2080,3 +2080,4 @@ GLIBC_2.17
 GLIBC_2.18
  GLIBC_2.18 A
  __cxa_thread_atexit_impl F
+ _mcount F
-- 
1.8.1.2