sync changelog with gcc, plus commit the following patch:

2010-06-09  Iain Sandoe  <iains@gcc.gnu.org>

	PR bootstrap/43170
	* tls.m4 (GCC_CHECK_TLS): Add volatile qualifier to the test
	references.  Move the main () test reference ahead of
	pthread_create().  Add a comment to explain the requirements
	of the test.

diff --git a/config/ChangeLog b/config/ChangeLog
index e0561d2f1424e44954a5e70487cfdec5dabc07bb..27f49c2ee6a0a7fcfa09306a4bf6aebb0f328eeb 100644 (file)
--- a/config/ChangeLog
+++ b/config/ChangeLog
@@ -1,25 +1,35 @@
+2010-06-09  Iain Sandoe  <iains@gcc.gnu.org>
+
+       PR bootstrap/43170
+       * tls.m4 (GCC_CHECK_TLS): Add volatile qualifier to the test 
+       references.  Move the main () test reference ahead of 
+       pthread_create().  Add a comment to explain the requirements
+       of the test.
+
 2010-06-03  Joern Rennecke <joern.rennecke@embecosm.com>
-            Ralf Wildenhues  <Ralf.Wildenhues@gmx.de>
+           Ralf Wildenhues  <Ralf.Wildenhues@gmx.de>
 
-       Sync from GCC:
        PR bootstrap/42798
        * override.m4 (_AC_CHECK_DECL_BODY, _AC_CHECK_DECLS): Import
        definitions from git Autoconf.
 
-2010-06-01  Ralf Wildenhues  <Ralf.Wildenhues@gmx.de>
-
-       Sync from GCC:
+2010-04-13  Steve Ellcey  <sje@cup.hp.com>
 
-       2010-04-13  Steve Ellcey  <sje@cup.hp.com>
        * elf.m4: Add hppa[12]*-*-hpux* to list of non-elf platforms.
 
-       2010-01-05  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
+2010-03-23  Kai Tietz  <kai.tietz@onevision.com>
+
+       * mh-mingw: Revert accidentally checking r156315.
+
+2010-01-05  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
+
        * stdint.m4 (GCC_HEADER_STDINT): Don't typedef uint8_t etc. if
        corresponding macros already exist.
 
-2010-02-15  Nick Clifton  <nickc@redhat.com>
+2010-01-02  Richard Guenther  <rguenther@suse.de>
 
-       * elf.m4: Import from gcc mainline.
+       PR lto/41529
+       * elf.m4: New file.
 
 2009-11-30  Joseph Myers  <joseph@codesourcery.com>
 

diff --git a/config/tls.m4 b/config/tls.m4
index ef7e6d0b555bad6dc41a8de4a13683115686f978..4e170c8d6aec3194bc1124b7726ae478b0fcdbff 100644 (file)
--- a/config/tls.m4
+++ b/config/tls.m4
@@ -38,11 +38,16 @@ AC_DEFUN([GCC_CHECK_TLS], [
        CFLAGS="$chktls_save_CFLAGS"
        if test "X$thread_CFLAGS" != Xfailed; then
          CFLAGS="$thread_CFLAGS $chktls_save_CFLAGS"
+         dnl Test for an old glibc bug that violated the __thread property.
+         dnl Use volatile to ensure the compiler won't optimize away pointer
+         dnl accesses it might otherwise assume to be redundant, or reorder 
+         dnl them and reuse storage, which might lead to them pointing to
+         dnl the same location.
          AC_RUN_IFELSE(
            [AC_LANG_PROGRAM(
               [#include <pthread.h>
                __thread int a;
-               static int *a_in_other_thread;
+               static int *volatile a_in_other_thread;
                static void *
                thread_func (void *arg)
                {
@@ -51,11 +56,11 @@ AC_DEFUN([GCC_CHECK_TLS], [
                }],
               [pthread_t thread;
                void *thread_retval;
-               int *a_in_main_thread;
+               int *volatile a_in_main_thread;
+               a_in_main_thread = &a;
                if (pthread_create (&thread, (pthread_attr_t *)0,
                                    thread_func, (void *)0))
                  return 0;
-               a_in_main_thread = &a;
                if (pthread_join (thread, &thread_retval))
                  return 0;
                return (a_in_other_thread == a_in_main_thread);])],