On Thu, Jan 16, 2020 at 10:52:06AM +0100, Martin Pieuchot wrote: > Found while compiling sgi kernel: > > /sys/netinet/igmp.c:140:22: error: implicit conversion from 'int' to 'int8_t' > (aka 'signed char') changes value from 148 to -108 > [-Werror,-Wconstant-conversion] > ra->ipopt_list[0] = IPOPT_RA; > ~ ^~~~~~~~ > /sys/netinet/ip.h:153:19: note: expanded from macro 'IPOPT_RA' > > Use an unsigned type in this case:
People argued against some of these types of changes previously. That is why kernels built with clang use -Wno-constant-conversion. patrick proposed this change in 2017 but it didn't happen https://marc.info/?l=openbsd-tech&m=148490401504785&w=2 > > Index: netinet/ip_var.h > =================================================================== > RCS file: /cvs/src/sys/netinet/ip_var.h,v > retrieving revision 1.86 > diff -u -p -r1.86 ip_var.h > --- netinet/ip_var.h 8 Dec 2019 11:08:22 -0000 1.86 > +++ netinet/ip_var.h 16 Jan 2020 09:48:41 -0000 > @@ -92,7 +92,7 @@ struct ipstat { > > struct ipoption { > struct in_addr ipopt_dst; /* first-hop dst if source routed */ > - int8_t ipopt_list[MAX_IPOPTLEN]; /* options proper */ > + uint8_t ipopt_list[MAX_IPOPTLEN]; /* options proper */ > }; > > #ifdef _KERNEL > >
