[Bug c++/12258] New: -Wold-style-cast triggers on casts in macros from system headers

[stl at caltech dot edu]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12258

           Summary: -Wold-style-cast triggers on casts in macros from system
                    headers
           Product: gcc
           Version: 3.3
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: stl at caltech dot edu
                CC: gcc-bugs at gcc dot gnu dot org

See this thread:
http://gcc.gnu.org/ml/gcc/2003-09/msg00162.html

Basically, if something like

#pragma GCC system_header
#define NOTHING (int) 0

appears in something.h, and meow.cc consists of

#include <something.h>
int blah = NOTHING;

and meow.cc is compiled with -Wold-style-cast, the warning will trigger.

I originally encountered this using MinGW gcc 3.3, but Zack Weinberg's 
comments in the thread indicate that no version of gcc anywhere yet knows 
enough to not emit this warning.