C99 math-type macros

[Schleicher Ralph (LLI)]

autoconf (GNU Autoconf) 2.53

Hi,

on hppa2.0w-hp-hpux11.00, the Autoconf macro sequence

    AC_SEARCH_LIBS([pow], [m])
    AC_CHECK_FUNCS([isinf])

reports

    checking for library containing pow... -lm
    checking for isinf... no

The manual page for isinf(3) says:

   "The isinf() macro replaces the isinf() and isinff() functions,
    which are obsolete and are no longer supported."

Well, C99 replaces the traditional isnan() and isinf() functions with
generic isnan() and isinf() math-type macros.  When the traditional
symbols are removed from the math library, the Autoconf test fails.
There seems to be a need for a new Autoconf test taking care for the
C99 math-type macros.  Up to now I use the following test:

# RS_CHECK_MATH_FUNC(FUNCTION)
# ----------------------------
AC_DEFUN([RS_CHECK_MATH_FUNC],
[dnl
AC_MSG_CHECKING([for $1])
AC_TRY_LINK([#include <math.h>],
            [#ifdef $1
             char *__conftest = 0;
             #else
             char *__conftest = (char *) $1;
             #endif],
            [AC_MSG_RESULT([yes])
             AC_DEFINE_UNQUOTED(AS_TR_CPP([HAVE_$1]), [1],
                                [Define to 1 if you have
                                 the `$1' function.])],
            [AC_MSG_RESULT([no])])])

It would be nice if support for C99 math-type macros could be added to
Autoconf.  Thanks,

-- 
Ralph Schleicher

System Engineering
Environmental Control Systems

Liebherr-Aerospace Lindenberg GmbH
P.O. Box 1363 * 88153 Lindenberg * Germany
Phone +49-8381-46-4057 * Fax +49-8381-46-4623