gcc/config/futex.m4
Jakub Jelinek 0f3e711eef configure.ac (--enable-linux-futex): Add new configure option.
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.

From-SVN: r131399
2008-01-08 17:14:49 +01:00

65 lines
1.8 KiB
Plaintext

dnl ----------------------------------------------------------------------
dnl This whole bit snagged from libgomp.
dnl
dnl GCC_LINUX_FUTEX
dnl (SHELL-CODE_HANDLER)
dnl
AC_DEFUN([GCC_LINUX_FUTEX],[dnl
GCC_ENABLE(linux-futex,default, ,[use the Linux futex system call],
permit yes|no|default)
case "$target" in
*-linux*)
case "$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);])],
[save_LIBS="$LIBS"
LIBS="-lpthread $LIBS"
AC_LINK_IFELSE(
[AC_LANG_PROGRAM(
[#ifndef _GNU_SOURCE
#define _GNU_SOURCE 1
#endif
#include <pthread.h>
pthread_t th; void *status;],
[pthread_tryjoin_np (th, &status);])],[enable_linux_futex=yes],
[if test x$cross_compiling = xno; then
if getconf GNU_LIBPTHREAD_VERSION 2>/dev/null \
| LC_ALL=C grep -i NPTL > /dev/null 2>/dev/null; then :; else
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])
LIBS="$save_LIBS"])
;;
yes)
AC_LINK_IFELSE(
[AC_LANG_PROGRAM(
[#include <sys/syscall.h>
int lk;],
[syscall (SYS_gettid); syscall (SYS_futex, &lk, 0, 0, 0);])],[],
[AC_MSG_ERROR([SYS_gettid and SYS_futex required for --enable-linux-futex])])
;;
esac
;;
*)
enable_linux_futex=no
;;
esac
if test x$enable_linux_futex = xyes; then
$1
fi
])