Date: Tue, 01 Nov 2011 01:10:36 -0600 From: Axel Gonzalez <loox@e-shell.net> To: Roman Divacky <rdivacky@freebsd.org> Cc: freebsd-current@freebsd.org Subject: Re: Strange warning with clang and 9RC1 (ntohs) Message-ID: <2104381.NqWTZMXtng@moonlight.e-shell.tk> In-Reply-To: <20111101065651.GA27751@freebsd.org> References: <1562351.Ln9lEKl2rv@moonlight.e-shell.tk> <20111101065651.GA27751@freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
Here is the output (short version):
...
(snip)
static __inline __uint16_t
__bswap16_var(__uint16_t _x)
{
return ((__uint16_t)((_x) << 8 | (_x) >> 8));
}
...
(snip)
int main()
{
uint16_t x = (__builtin_constant_p(80) ? (__uint16_t)(((__uint16_t)(80)) << 8
| ((__uint16_t)(80)) >> 8) : __bswap16_var(80));
printf("%hu\n", (uint16_t)(__builtin_constant_p(x) ? (__uint16_t)
(((__uint16_t)(x)) << 8 | ((__uint16_t)(x)) >> 8) : __bswap16_var(x)));
printf("%hu\n", (__builtin_constant_p(x) ? (__uint16_t)(((__uint16_t)(x)) <<
8 | ((__uint16_t)(x)) >> 8) : __bswap16_var(x)));
return (0);
}
% clang -E ntohs.c > ntohs_.c
% clang -Wall -o ntohs ntohs_.c
In file included from ntohs.c:1:
ntohs.c:8:12: warning: conversion specifies type 'unsigned short' but the
argument has type
'int' [-Wformat]
...%hu\n", (__builtin_constant_p(x) ? (__uint16_t)(((__uint16_t)(x)) << 8 |
((__uint16_t)(x)) >> 8) : __bswap16_var(x))...
~~^
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
%d
1 warning generated.
And I missed it the first mail:
FreeBSD moonlight 9.0-RC1 FreeBSD 9.0-RC1 #0: Fri Oct 28 22:53:45 CDT 2011
toor@moonlight:/usr/obj/usr/src/sys/LXCORE9 i386
Thanks!
A
On Tuesday 01 November 2011 07:56:51 Roman Divacky wrote:
> It doesnt warn here. Can you check with "clang -E" what the ntohs()
> is being expanded to and what the real prototype is?
>
--
Tue Nov 1 01:01:15 2011 GMT
**
*****
******
*******
*******
******
*****
** 6.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?2104381.NqWTZMXtng>