itojun@iijlab.net wrote:

> 
> >Sources updated this morning; macppc:
> >cc  -O2 -pipe -Werror -Wreturn-type -Wpointer-arith 
> >-Wno-uninitialized -Wno-main -msoft-float -I. -I../../../../arch 
> >-I../../../.. -nostdinc -I../../../../../crypto-intl/sys 
> >-I../../../../../gnu/sys -DLKM -DDIAGNOSTIC -DTRAP_PANICWAIT 
> >-DNMBCLUSTERS="0x400" -DMAXUSERS=64 -D_KERNEL -Dmacppc  -c 
> >../../../../netinet6/icmp6.c
> >cc1: warnings being treated as errors
> >../../../../netinet6/icmp6.c: In function `ni6_dnsmatch':
> >../../../../netinet6/icmp6.c:1419: warning: comparison is always 0 
> >due to limited range of data type
> >../../../../netinet6/icmp6.c:1419: warning: comparison is always 0 
> >due to limited range of data type
> >*** Error code 1
> 
> 	how can I suppress the warning in this case?  it looks that macppc
> 	treats char as unsigned char, while for i386 char is signed.
> 	if the char is signed, I really need to check for negative numbers. 
> 
> itojun
> 
> 
> ---
> static int
> ni6_dnsmatch(a, alen, b, blen)
> 	const char *a;
> 	int alen;
> 	const char *b;
> 	int blen;
> {
> 	/* ... */
> 
> 	if (a[0] < 0 || b[0] < 0)	<---	line 1419 in the above
> 		return 0;
> 
> 	/* ... */
> }

Would something like:

	if ((signed char)a[0] < 0 || (signed char)b[0] < 0)

work?