-Wconversion considers unsigned short int unequal to itself?

[Marc Glisse]

On Mon, 22 Feb 2010, Davies, Aaron wrote:

> I discoved the following behavior while trying to get warnings-clean on some existing code. It was intially found in a call to ntohs(3); the below snippet isolates it. Is this warning expected?
>
> $ gcc --version
> gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-44)
> Copyright (C) 2006 Free Software Foundation, Inc.
> This is free software; see the source for copying conditions.  There is NO
> warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
>
> $ cat test.c
> int f(unsigned short int i){return i;}
> int main(int c,char**v){return f((unsigned short int)0);}
> $ gcc -Wall -Wconversion test.c
> test.c: In function 'main':
> test.c:2: warning: passing argument 1 of 'f' with different width due to prototype

gcc-4.3 and later don't give this warning anymore.

-- 
Marc Glisse