New module 'ceill'.

[gnulib.git] / m4 / ceill.m4

diff --git a/m4/ceill.m4 b/m4/ceill.m4
new file mode 100644 (file)
index 0000000..7413a31
--- /dev/null
+++ b/m4/ceill.m4
@@ -0,0 +1,48 @@
+# ceill.m4 serial 1
+dnl Copyright (C) 2007 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.
+
+AC_DEFUN([gl_FUNC_CEILL],
+[
+  AC_REQUIRE([gl_MATH_H_DEFAULTS])
+  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>])
+  if test "$ac_cv_have_decl_ceill" = yes; then
+    dnl Test whether ceill() can be used without libm.
+    CEILL_LIBM=?
+    AC_TRY_LINK([
+       #ifndef __NO_MATH_INLINES
+       # define __NO_MATH_INLINES 1 /* for glibc */
+       #endif
+       #include <math.h>
+       long double x;],
+      [x = ceill(x);],
+      [CEILL_LIBM=])
+    if test "$CEILL_LIBM" = "?"; then
+      save_LIBS="$LIBS"
+      LIBS="$LIBS -lm"
+      AC_TRY_LINK([
+         #ifndef __NO_MATH_INLINES
+         # define __NO_MATH_INLINES 1 /* for glibc */
+         #endif
+         #include <math.h>
+         long double x;],
+        [x = ceill(x);],
+        [CEILL_LIBM="-lm"])
+      LIBS="$save_LIBS"
+    fi
+    if test "$CEILL_LIBM" = "?"; then
+      CEILL_LIBM=
+    fi
+  else
+    HAVE_DECL_CEILL=0
+    AC_LIBOBJ([ceill])
+    CEILL_LIBM=
+  fi
+  AC_SUBST([HAVE_DECL_CEILL])
+  AC_SUBST([CEILL_LIBM])
+])