Fix canonicalize loop-detection corner case.

[gnulib.git] / m4 / nanosleep.m4

diff --git a/m4/nanosleep.m4 b/m4/nanosleep.m4
index 56c66bb..1d832a3 100644 (file)
--- a/m4/nanosleep.m4
+++ b/m4/nanosleep.m4
@@ -1,12 +1,12 @@
-#serial 17
+#serial 23

 
 dnl From Jim Meyering.
 dnl Check for the nanosleep function.
 dnl If not found, use the supplied replacement.
 dnl
 
 
 dnl From Jim Meyering.
 dnl Check for the nanosleep function.
 dnl If not found, use the supplied replacement.
 dnl
 

-# Copyright (C) 1999, 2000, 2001, 2003, 2004, 2005, 2006 Free Software
-# Foundation, Inc.
+# Copyright (C) 1999, 2000, 2001, 2003, 2004, 2005, 2006, 2007 Free
+# Software Foundation, Inc.

 
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
 
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,


@@ -14,12 +14,11 @@ dnl
 
 AC_DEFUN([gl_FUNC_NANOSLEEP],
 [
 
 AC_DEFUN([gl_FUNC_NANOSLEEP],
 [

- AC_LIBSOURCES([nanosleep.c])
-

  dnl Persuade glibc and Solaris <time.h> to declare nanosleep.
  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
 
  dnl Persuade glibc and Solaris <time.h> to declare nanosleep.
  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
 

- AC_REQUIRE([AC_HEADER_TIME])
+ AC_REQUIRE([gl_HEADER_TIME_H_DEFAULTS])
+ AC_REQUIRE([gl_CLOCK_TIME])

  AC_CHECK_HEADERS_ONCE(sys/time.h)
 
  nanosleep_save_libs=$LIBS
  AC_CHECK_HEADERS_ONCE(sys/time.h)
 
  nanosleep_save_libs=$LIBS


@@ -29,42 +28,83 @@ AC_DEFUN([gl_FUNC_NANOSLEEP],
  AC_SEARCH_LIBS([nanosleep], [rt posix4],
                 [test "$ac_cv_search_nanosleep" = "none required" ||
                 LIB_NANOSLEEP=$ac_cv_search_nanosleep])
  AC_SEARCH_LIBS([nanosleep], [rt posix4],
                 [test "$ac_cv_search_nanosleep" = "none required" ||
                 LIB_NANOSLEEP=$ac_cv_search_nanosleep])

- AC_SUBST([LIB_NANOSLEEP])

 
 

- AC_CACHE_CHECK([for nanosleep],
+ AC_CACHE_CHECK([for working nanosleep],

   [gl_cv_func_nanosleep],
   [
   [gl_cv_func_nanosleep],
   [

-   AC_LINK_IFELSE([AC_LANG_SOURCE([[
-#   if TIME_WITH_SYS_TIME
-#    include <sys/time.h>
-#    include <time.h>
-#   else
-#    if HAVE_SYS_TIME_H
-#     include <sys/time.h>
-#    else
-#     include <time.h>
-#    endif
-#   endif
+   AC_RUN_IFELSE(
+     [AC_LANG_SOURCE([[
+       #include <errno.h>
+       #include <limits.h>
+       #include <signal.h>
+       #if HAVE_SYS_TIME_H
+        #include <sys/time.h>
+       #endif
+       #include <time.h>
+       #include <unistd.h>
+       #define TYPE_SIGNED(t) (! ((t) 0 < (t) -1))
+       #define TYPE_MAXIMUM(t) \
+         ((t) (! TYPE_SIGNED (t) \
+               ? (t) -1 \
+               : ~ (~ (t) 0 << (sizeof (t) * CHAR_BIT - 1))))

 
 

-    int
-    main ()
-    {
-      struct timespec ts_sleep, ts_remaining;
-      ts_sleep.tv_sec = 0;
-      ts_sleep.tv_nsec = 1;
-      return nanosleep (&ts_sleep, &ts_remaining) < 0;
-    }
-      ]])],
+       static void
+       check_for_SIGALRM (int sig)
+       {
+         if (sig != SIGALRM)
+           _exit (1);
+       }
+
+       int
+       main ()
+       {
+         static struct timespec ts_sleep;
+         static struct timespec ts_remaining;
+         static struct sigaction act;
+         if (! nanosleep)
+           return 1;
+         act.sa_handler = check_for_SIGALRM;
+         sigemptyset (&act.sa_mask);
+         sigaction (SIGALRM, &act, NULL);
+         ts_sleep.tv_sec = 0;
+         ts_sleep.tv_nsec = 1;
+         alarm (1);
+         if (nanosleep (&ts_sleep, NULL) != 0)
+           return 1;
+         ts_sleep.tv_sec = TYPE_MAXIMUM (time_t);
+         ts_sleep.tv_nsec = 999999999;
+         alarm (1);
+         if (nanosleep (&ts_sleep, &ts_remaining) == -1 && errno == EINTR
+             && TYPE_MAXIMUM (time_t) - 10 < ts_remaining.tv_sec)
+           return 0;
+         return 119;
+       }]])],

      [gl_cv_func_nanosleep=yes],
      [gl_cv_func_nanosleep=yes],

-     [gl_cv_func_nanosleep=no])
+     [case $? in dnl (
+      119) gl_cv_func_nanosleep='no (mishandles large arguments)';; dnl (
+      *)   gl_cv_func_nanosleep=no;;
+      esac],
+     [gl_cv_func_nanosleep=cross-compiling])

   ])
   ])

-  if test $gl_cv_func_nanosleep = no; then
+  if test "$gl_cv_func_nanosleep" = yes; then
+    REPLACE_NANOSLEEP=0
+  else
+    REPLACE_NANOSLEEP=1
+    if test "$gl_cv_func_nanosleep" = 'no (mishandles large arguments)'; then
+      AC_DEFINE([HAVE_BUG_BIG_NANOSLEEP], 1,
+       [Define to 1 if nanosleep mishandles large arguments.])
+      for ac_lib in $LIB_CLOCK_GETTIME; do
+       case " $LIB_NANOSLEEP " in
+       *" $ac_lib "*) ;;
+       *) LIB_NANOSLEEP="$LIB_NANOSLEEP $ac_lib";;
+       esac
+      done
+    fi

     AC_LIBOBJ(nanosleep)
     AC_LIBOBJ(nanosleep)

-    AC_DEFINE(nanosleep, rpl_nanosleep,
-      [Define to rpl_nanosleep if the replacement function should be used.])

     gl_PREREQ_NANOSLEEP
   fi
 
     gl_PREREQ_NANOSLEEP
   fi
 

+ AC_SUBST([LIB_NANOSLEEP])

  LIBS=$nanosleep_save_libs
 ])
 
  LIBS=$nanosleep_save_libs
 ])