Fix test failure on Cygwin.

[gnulib.git] / m4 / strtod.m4

diff --git a/m4/strtod.m4 b/m4/strtod.m4
index 8aaf4b7..5d52617 100644 (file)
--- a/m4/strtod.m4
+++ b/m4/strtod.m4
@@ -1,69 +1,79 @@
-## Copyright (C) 1996 Free Software Foundation, Inc.
+# strtod.m4 serial 9
+dnl Copyright (C) 2002, 2003, 2006, 2007, 2008 Free Software
+dnl 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.
 
-## This program is free software; you can redistribute it and/or modify
-## it under the terms of the GNU General Public License as published by
-## the Free Software Foundation; either version 2, or (at your option)
-## any later version.
-
-## This program is distributed in the hope that it will be useful,
-## but WITHOUT ANY WARRANTY; without even the implied warranty of
-## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-## GNU General Public License for more details.
-
-## You should have received a copy of the GNU General Public License
-## along with this program; if not, write to the Free Software
-## Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
-## 02111-1307, USA.
-
-## From Jim Meyering.
-
-## serial 1
-
-## @defmac AC_FUNC_STRTOD
-## @maindex FUNC_STRTOD
-## @ovindex LIBOBJS
-## If the @code{strtod} function is not available, or does not work
-## correctly (like the one on SunOS 5.4), add @samp{strtod.o} to output
-## variable @code{LIBOBJS}.
-## @end defmac
-
-AC_DEFUN(AM_FUNC_STRTOD,
-[AC_CACHE_CHECK(for working strtod, am_cv_func_strtod,
-[AC_TRY_RUN([
-double strtod ();
-int
-main()
+AC_DEFUN([gl_FUNC_STRTOD],
+[
+  AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
+  AC_FUNC_STRTOD
+  dnl Note: AC_FUNC_STRTOD does AC_LIBOBJ(strtod).
+  if test $ac_cv_func_strtod = no; then
+    HAVE_STRTOD=0
+    REPLACE_STRTOD=1
+    gl_PREREQ_STRTOD
+  else
+    AC_CACHE_CHECK([whether strtod obeys C99], [gl_cv_func_strtod_works],
+      [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+#include <stdlib.h>
+#include <math.h>
+/* Compare two numbers with ==.
+   This is a separate function because IRIX 6.5 "cc -O" miscompiles an
+   'x == x' test.  */
+static int
+numeric_equal (double x, double y)
 {
+  return x == y;
+}
+]], [[
   {
-    /* Some versions of Linux strtod mis-parse strings with leading '+'.  */
-    char *string = " +69";
+    /* Older glibc and Cygwin mis-parse "-0x".  */
+    const char *string = "-0x";
     char *term;
-    double value;
-    value = strtod (string, &term);
-    if (value != 69 || term != (string + 4))
-      exit (1);
+    double value = strtod (string, &term);
+    double zero = 0.0;
+    if (1.0 / value != -1.0 / zero || term != (string + 2))
+      return 1;
   }
-
   {
-    /* Under Solaris 2.4, strtod returns the wrong value for the
-       terminating character under some conditions.  */
-    char *string = "NaN";
+    /* Many platforms do not parse hex floats.  */
+    const char *string = "0XaP+1";
     char *term;
-    strtod (string, &term);
-    if (term != string && *(term - 1) == 0)
-      exit (1);
+    double value = strtod (string, &term);
+    if (value != 20.0 || term != (string + 6))
+      return 1;
   }
-  exit (0);
-}
-], am_cv_func_strtod=yes, am_cv_func_strtod=no, am_cv_func_strtod=no)])
-test $am_cv_func_strtod = no && LIBOBJS="$LIBOBJS strtod.o"
-AC_SUBST(LIBOBJS)dnl
-am_cv_func_strtod_needs_libm=no
-if test $am_cv_func_strtod = no; then
-  AC_CHECK_FUNCS(pow)
-  if test $ac_cv_func_pow = no; then
-    AC_CHECK_LIB(m, pow, [am_cv_func_strtod_needs_libm=yes],
-                [AC_MSG_WARN(can't find library containing definition of pow)])
+  {
+    /* Many platforms do not parse infinities.  */
+    const char *string = "inf";
+    char *term;
+    double value = strtod (string, &term);
+    if (value != HUGE_VAL || term != (string + 3))
+      return 1;
+  }
+  {
+    /* glibc 2.7 and cygwin 1.5.24 misparse "nan()".  */
+    const char *string = "nan()";
+    char *term;
+    double value = strtod (string, &term);
+    if (numeric_equal (value, value) || term != (string + 5))
+      return 1;
+  }
+]])],
+       [gl_cv_func_strtod_works=yes],
+       [gl_cv_func_strtod_works=no],
+       [gl_cv_func_strtod_works="guessing no"])])
+    if test "$gl_cv_func_strtod_works" != yes; then
+      REPLACE_STRTOD=1
+      gl_PREREQ_STRTOD
+      dnl Use undocumented macro to set POW_LIB correctly.
+      _AC_LIBOBJ_STRTOD
+    fi
   fi
-fi
 ])
+
+# Prerequisites of lib/strtod.c.
+# The need for pow() is already handled by AC_FUNC_STRTOD.
+AC_DEFUN([gl_PREREQ_STRTOD], [:])