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|
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
])
|
