[Bug preprocessor/16358] -Wno-system-headers hides warning caused by user header vs system header conflict

[giovannibajo at libero dot it]

------- Additional Comments From giovannibajo at libero dot it  2004-07-05 16:15 -------
I agree with Avi. The system header doesn't do a #undef + #define, but just a 
#define and it silently overwrites the previous macro. Even if this is 
undefined behaviour, we can do better than we do now and emit at least a 
warning.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |UNCONFIRMED
         Resolution|INVALID                     |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16358