[patch] cooperation between gcc's and mingw's float.h

[Mark Brand <mabrand at mabrand dot nl>]

 Hi,

I'm reluctantly cross-posting because this issue requires cooperation 
between gcc and mingw.

Both mingw and gcc have a float.h. The mingw version supplements the gcc 
version, declaring _clear87 and _control87 among other things. The mingw 
version has an #include_next which is meant to include the gcc version. 
This works only when the mingw include dir is first in the header search 
path, which may not be correct.

When the header search list is ordered with the mingw include directory 
after the gcc's, a common symptom is that _clear87 and _control87 are 
undeclared.

A web search for "mingw gcc float.h _clear87" turns up lots of 
references to this problem, one of which is here:
http://bugreports.qt.nokia.com/browse/QTBUG-7576.

An easy (and correct?) solution is to move the #include_next<float.h> 
from the mingw version into the gcc version regards. The attached 
patches do this. But I imagine some discussion might be needed.

These patches are against  tarballs gcc-4.5.0.tar.bz2 and 
mingwrt-3.18-mingw32-dev.tar.gz

Mark
diff -urN a/gcc/ginclude/float.h b/gcc/ginclude/float.h
--- a/gcc/ginclude/float.h	2009-04-09 17:00:19.000000000 +0200
+++ b/gcc/ginclude/float.h	2010-06-05 12:03:41.887724045 +0200
@@ -236,3 +236,7 @@
 #endif /* __STDC_WANT_DEC_FP__ */
 
 #endif /* _FLOAT_H___ */
+
+#ifdef __MINGW32__
+#include_next<float.h>
+#endif

diff -urN a/include/float.h b/include/float.h
--- a/include/float.h	2010-03-07 04:31:41.000000000 +0100
+++ b/include/float.h	2010-06-05 12:29:08.899723741 +0200
@@ -16,8 +16,6 @@
  *
  */
 
-#include_next<float.h>
-
 #ifndef _MINGW_FLOAT_H_
 #define _MINGW_FLOAT_H_