m4/c-strtod.m4

   1 # c-strtod.m4 serial 15
   2
   3 # Copyright (C) 2004-2006, 2009-2014 Free Software Foundation, Inc.
   4 # This file is free software; the Free Software Foundation
   5 # gives unlimited permission to copy and/or distribute it,
   6 # with or without modifications, as long as this notice is preserved.
   7
   8 # Written by Paul Eggert.
   9
  10 AC_DEFUN([gl_C99_STRTOLD],
  11 [
  12   AC_CACHE_CHECK([whether strtold conforms to C99],
  13     [gl_cv_func_c99_strtold],
  14     [AC_LINK_IFELSE(
  15        [AC_LANG_PROGRAM(
  16           [[/* On HP-UX before 11.23, strtold returns a struct instead of
  17                 long double.  Reject implementations like that, by requiring
  18                 compatibility with the C99 prototype.  */
  19              #include <stdlib.h>
  20              static long double (*p) (char const *, char **) = strtold;
  21              static long double
  22              test (char const *nptr, char **endptr)
  23              {
  24                long double r;
  25                r = strtold (nptr, endptr);
  26                return r;
  27              }]],
  28            [[return test ("1.0", NULL) != 1 || p ("1.0", NULL) != 1;]])],
  29        [gl_cv_func_c99_strtold=yes],
  30        [gl_cv_func_c99_strtold=no])])
  31   if test $gl_cv_func_c99_strtold = yes; then
  32     AC_DEFINE([HAVE_C99_STRTOLD], [1], [Define to 1 if strtold conforms to C99.])
  33   fi
  34 ])
  35
  36 dnl Prerequisites of lib/c-strtod.c.
  37 AC_DEFUN([gl_C_STRTOD],
  38 [
  39   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
  40   AC_CHECK_FUNCS([strtod_l])
  41 ])
  42
  43 dnl Prerequisites of lib/c-strtold.c.
  44 AC_DEFUN([gl_C_STRTOLD],
  45 [
  46   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
  47   AC_REQUIRE([gl_C99_STRTOLD])
  48   AC_CHECK_FUNCS([strtold_l])
  49 ])