strtoumax: fix typo in previous commit.

[gnulib.git] / m4 / ceill.m4

diff --git a/m4/ceill.m4 b/m4/ceill.m4
index 8116de1..e26c1b0 100644 (file)
--- a/m4/ceill.m4
+++ b/m4/ceill.m4
@@ -1,5 +1,5 @@
-# ceill.m4 serial 9
-dnl Copyright (C) 2007, 2009-2011 Free Software Foundation, Inc.
+# ceill.m4 serial 14
+dnl Copyright (C) 2007, 2009-2013 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -8,10 +8,13 @@ AC_DEFUN([gl_FUNC_CEILL],
 [
   m4_divert_text([DEFAULTS], [gl_ceill_required=plain])
   AC_REQUIRE([gl_MATH_H_DEFAULTS])
+  AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])
+
   dnl Persuade glibc <math.h> to declare ceill().
   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
   dnl Test whether ceill() is declared.
-  AC_CHECK_DECLS([ceill], , , [#include <math.h>])
+  AC_CHECK_DECLS([ceill], , , [[#include <math.h>]])
   if test "$ac_cv_have_decl_ceill" = yes; then
     dnl Test whether ceill() can be used without libm.
     gl_FUNC_CEILL_LIBS
@@ -22,6 +25,7 @@ AC_DEFUN([gl_FUNC_CEILL],
     fi
     m4_ifdef([gl_FUNC_CEILL_IEEE], [
       if test $gl_ceill_required = ieee && test $REPLACE_CEILL = 0; then
+        AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
         AC_CACHE_CHECK([whether ceill works according to ISO C 99 with IEC 60559],
           [gl_cv_func_ceill_ieee],
           [
@@ -35,17 +39,25 @@ AC_DEFUN([gl_FUNC_CEILL],
 #include <math.h>
 ]gl_LONG_DOUBLE_MINUS_ZERO_CODE[
 ]gl_LONG_DOUBLE_SIGNBIT_CODE[
-int main()
+static long double dummy (long double f) { return 0; }
+int main (int argc, char *argv[])
 {
+  long double (*my_ceill) (long double) = argc ? ceill : dummy;
   /* Test whether ceill (-0.3L) is -0.0L.  */
-  if (signbitl (minus_zerol) && !signbitl (ceill (-0.3L)))
+  if (signbitl (minus_zerol) && !signbitl (my_ceill (-0.3L)))
     return 1;
   return 0;
 }
               ]])],
               [gl_cv_func_ceill_ieee=yes],
               [gl_cv_func_ceill_ieee=no],
-              [gl_cv_func_ceill_ieee="guessing no"])
+              [case "$host_os" in
+                         # Guess yes on glibc systems.
+                 *-gnu*) gl_cv_func_ceill_ieee="guessing yes" ;;
+                         # If we don't know, assume the worst.
+                 *)      gl_cv_func_ceill_ieee="guessing no" ;;
+               esac
+              ])
             LIBS="$save_LIBS"
           ])
         case "$gl_cv_func_ceill_ieee" in
@@ -58,8 +70,13 @@ int main()
     HAVE_DECL_CEILL=0
   fi
   if test $HAVE_DECL_CEILL = 0 || test $REPLACE_CEILL = 1; then
-    dnl No libraries are needed to link lib/ceill.c.
-    CEILL_LIBM=
+    dnl Find libraries needed to link lib/ceill.c.
+    if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then
+      AC_REQUIRE([gl_FUNC_CEIL])
+      CEILL_LIBM="$CEIL_LIBM"
+    else
+      CEILL_LIBM=
+    fi
   fi
   AC_SUBST([CEILL_LIBM])
 ])
@@ -76,8 +93,9 @@ AC_DEFUN([gl_FUNC_CEILL_LIBS],
            # define __NO_MATH_INLINES 1 /* for glibc */
            #endif
            #include <math.h>
+           long double (*funcptr) (long double) = ceill;
            long double x;]],
-         [[x = ceill(x);]])],
+         [[x = funcptr(x) + ceill(x);]])],
       [gl_cv_func_ceill_libm=])
     if test "$gl_cv_func_ceill_libm" = "?"; then
       save_LIBS="$LIBS"
@@ -88,8 +106,9 @@ AC_DEFUN([gl_FUNC_CEILL_LIBS],
              # define __NO_MATH_INLINES 1 /* for glibc */
              #endif
              #include <math.h>
+             long double (*funcptr) (long double) = ceill;
              long double x;]],
-           [[x = ceill(x);]])],
+           [[x = funcptr(x) + ceill(x);]])],
         [gl_cv_func_ceill_libm="-lm"])
       LIBS="$save_LIBS"
     fi