libstdc++-v3/

	* configure.ac (--enable-linux-futex): Add new configure option.
	(HAVE_LINUX_FUTEX): New AC_DEFINE.
	* Makefile.in: Rebuilt.
	* aclocal.m4: Rebuilt.
	* configure: Rebuilt.
	* config.h.in: Rebuilt.
	* config/cpu/generic/cxxabi_tweaks.h (_GLIBCXX_GUARD_BIT,
	_GLIBCXX_GUARD_PENDING_BIT, _GLIBCXX_GUARD_WAITING_BIT): Define.
	* config/cpu/arm/cxxabi_tweaks.h (_GLIBCXX_GUARD_BIT,
	_GLIBCXX_GUARD_PENDING_BIT, _GLIBCXX_GUARD_WAITING_BIT): Define.
	* libsupc++/guard.cc: Include climits and syscall.h.
	(_GLIBCXX_USE_FUTEX): Define if futex syscall and atomic builtins
	are supported.
	(_GLIBCXX_FUTEX_WAIT, _GLIBCXX_FUTEX_WAKE): Likewise.
	(__guard_test_bit): New static inline.
	(__cxa_guard_acquire, __cxa_guard_release, __cxa_guard_abort): Use
	atomic builtins and futex syscall if _GLIBCXX_USE_FUTEX.
config/
	* futex.m4: New file.
libgomp/
	* configure.ac: Move futex checking into ../config/futex.m4.
	* configure: Rebuilt.
	* aclocal.m4: Rebuilt.
	* Makefile.in: Rebuilt.

	* configure.tgt: Rename have_tls to gcc_cv_have_tls to match
	2007-10-15 ../config/tls.m4 change.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@131399 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 2 insertions, 48 deletions

diff --git a/libgomp/configure.ac b/libgomp/configure.ac
index 68a18e17561..0cda749d593 100644
--- a/libgomp/configure.ac
+++ b/libgomp/configure.ac
@@ -15,12 +15,6 @@ LIBGOMP_ENABLE(version-specific-runtime-libs, no, ,
    permit yes|no)
 AC_MSG_RESULT($enable_version_specific_runtime_libs)
 
-AC_MSG_CHECKING([for --enable-linux-futex])
-LIBGOMP_ENABLE(linux-futex, default, ,
-  [Use the Linux futex system call],
-  permit yes|no|default)
-AC_MSG_RESULT($enable_linux_futex)
-
 # We would like our source tree to be readonly. However when releases or
 # pre-releases are generated, the flex/bison generated files as well as the
 # various formats of manuals need to be included along with the rest of the
@@ -192,50 +186,10 @@ case "$host" in
     AC_DEFINE(HAVE_BROKEN_POSIX_SEMAPHORES, 1,
 	Define if the POSIX Semaphores do not work on your system.)
     ;;
-  *-linux*)
-    case "$enable_linux_futex" in
-      default)
-	# If headers don't have gettid/futex syscalls definition, then
-	# default to no, otherwise there will be compile time failures.
-	# Otherwise, default to yes.  If we don't detect we are
-	# compiled/linked against NPTL and not cross-compiling, check
-	# if programs are run by default against NPTL and if not, issue
-	# a warning.
-	enable_linux_futex=no
-	AC_LINK_IFELSE(
-	 [AC_LANG_PROGRAM(
-	  [#include <sys/syscall.h>
-	   int lk;],
-	  [syscall (SYS_gettid); syscall (SYS_futex, &lk, 0, 0, 0);])],
-	  [AC_LINK_IFELSE(
-	   [AC_LANG_PROGRAM(
-	    [#ifndef _GNU_SOURCE
-	     #define _GNU_SOURCE 1
-	     #endif
-	     #include <pthread.h>
-	     pthread_t th; void *status;],
-	    [pthread_tryjoin_np (th, &status);])],[enable_linux_futex=yes],
-	    [if test x$cross_compiling = xno; then
-	       if getconf GNU_LIBPTHREAD_VERSION 2>/dev/null \
-		  | LC_ALL=C grep -i NPTL > /dev/null 2>/dev/null; then
-		 AC_MSG_WARN([The kernel might not support futex or gettid syscalls.
-If so, please configure with --disable-linux-futex])
-	       fi
-	     fi
-	     enable_linux_futex=yes])])
-	;;
-      yes)
-	AC_LINK_IFELSE(
-	 [AC_LANG_PROGRAM(
-	  [#include <sys/syscall.h>
-	   int lk;],
-	  [syscall (SYS_gettid); syscall (SYS_futex, &lk, 0, 0, 0);])],[],
-	  [AC_MSG_ERROR([SYS_gettid and SYS_futex required for --enable-linux-futex])])
-	;;
-    esac
-    ;;
 esac
 
+GCC_LINUX_FUTEX(:)
+
 # Check for pthread_{,attr_}[sg]etaffinity_np.
 AC_LINK_IFELSE(
  [AC_LANG_PROGRAM(