bin/120025: warning in C++'s system header

[Mikhail T.]

>Number:         120025
>Category:       bin
>Synopsis:       warning in C++'s system header
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sat Jan 26 23:40:04 UTC 2008
>Closed-Date:
>Last-Modified:
>Originator:     Mikhail T.
>Release:        FreeBSD 8.0
>Organization:
Virtual Estates, Inc.
>Environment:
	7.x or 8.x system, where gcc-4.2 is the system compiler
>Description:

The following bug prevents ANY C++ code from being built with WARNS set
to anything, because -Wsystem-headers is included even when WARNS=1 (see
share/mk/bsd.sys.mk):

In file included from /usr/include/c++/4.2/ios:50,
                 from /usr/include/c++/4.2/ostream:45,
                 from /usr/include/c++/4.2/iostream:45,
		...
/usr/include/c++/4.2/bits/basic_ios.h: In member function 'void std::basic_ios<_CharT, _Traits>::_M_setstate(std::_Ios_Iostate)':
/usr/include/c++/4.2/bits/basic_ios.h:156: warning: empty body in an if-statement

>How-To-Repeat:

One example would be to build /usr/ports/graphics/libfpx/

>Fix:

Explicitly set NO_WERROR, as is currently done in 7.x. This defeats the
main purpose of WARNS, however...
>Release-Note:
>Audit-Trail:
>Unformatted: