From 18fdfeca8b587baf819ded68f68a8fa4b196d035 Mon Sep 17 00:00:00 2001
From: Florian Forster <octo@huhu.verplant.org>
Date: Tue, 19 Jun 2007 20:48:15 +0200
Subject: [PATCH] configure: Implemented `--with-nan-emulation' for
 crosscompiling.

When crosscompiling you cannot do the runtime checks for the (0.0 / 0.0) hack.
With this option you can force this implementation if neccessary.
---
 configure.in | 38 ++++++++++++++++++++++++++------------
 1 file changed, 26 insertions(+), 12 deletions(-)

diff --git a/configure.in b/configure.in
index a726b0bf..77f0e49c 100644
--- a/configure.in
+++ b/configure.in
@@ -413,7 +413,17 @@ AC_CHECK_FUNCS(getgrgid getpwuid)
 AC_CHECK_FUNCS(getifaddrs)
 
 # Check for NAN
-nan_type="none"
+AC_ARG_WITH(nan-emulation, [AS_HELP_STRING([--with-nan-emulation], [use emulated NAN. For crosscompiling only.])],
+[
+ if test "x$withval" = "xno"; then
+	 nan_type="none"
+ else if test "x$withval" = "xyes"; then
+	 nan_type="zero"
+ else
+	 nan_type="$withval"
+ fi; fi
+],
+[nan_type="none"])
 if test "x$nan_type" = "xnone"; then
   AC_CACHE_CHECK([whether NAN is defined by default],
     [have_nan_default],
@@ -436,9 +446,7 @@ static float foo = NAN;
   )
   if test "x$have_nan_default" = "xyes"
   then
-   nan_type="default"
-   AC_DEFINE(NAN_STATIC_DEFAULT, 1,
-     [Define if NAN is defined by default and can initialize static variables.])
+    nan_type="default"
   fi
 fi
 if test "x$nan_type" = "xnone"; then
@@ -464,9 +472,7 @@ static float foo = NAN;
   )
   if test "x$have_nan_isoc" = "xyes"
   then
-   nan_type="isoc99"
-   AC_DEFINE(NAN_STATIC_ISOC, 1,
-     [Define if NAN is defined by __USE_ISOC99 and can initialize static variables.])
+    nan_type="isoc99"
   fi
 fi
 if test "x$nan_type" = "xnone"; then
@@ -498,14 +504,22 @@ static float foo = NAN;
   )
   if test "x$have_nan_zero" = "xyes"
   then
-   nan_type="zero"
-   AC_DEFINE(NAN_ZERO_ZERO, 1,
-     [Define if NAN can be defined as (0.0 / 0.0)])
+    nan_type="zero"
   fi
 fi
-if test "x$nan_type" = "xnone"; then
+
+if test "x$nan_type" = "xdefault"; then
+  AC_DEFINE(NAN_STATIC_DEFAULT, 1,
+    [Define if NAN is defined by default and can initialize static variables.])
+else if test "x$nan_type" = "xisoc99"; then
+  AC_DEFINE(NAN_STATIC_ISOC, 1,
+    [Define if NAN is defined by __USE_ISOC99 and can initialize static variables.])
+else if test "x$nan_type" = "xzero"; then
+  AC_DEFINE(NAN_ZERO_ZERO, 1,
+    [Define if NAN can be defined as (0.0 / 0.0)])
+else
   AC_MSG_ERROR([Didn't find out how to statically initialize variables to NAN. Sorry.])
-fi
+fi; fi; fi
 
 # For mount interface
 #AC_CHECK_FUNCS(getfsent getvfsent)
-- 
2.11.0