Darren Reed wrote:
Looking through ip.c for the refactor review, I found this gem;
5900 ip_net_mask(ipaddr_t addr)
5901 {
5902 uchar_t *up = (uchar_t *)&addr;
5903 ipaddr_t mask = 0;
5904 uchar_t *maskp = (uchar_t *)&mask;
5905 5906 #if defined(__i386) || defined(__amd64)
5907 #define TOTALLY_BRAIN_DAMAGED_C_COMPILER
5908 #endif
5909 #ifdef TOTALLY_BRAIN_DAMAGED_C_COMPILER
5910 maskp[0] = maskp[1] = maskp[2] = maskp[3] = 0;
5911 #endif
It predates the refactoring project so I'm reluctant to mention it here
but has anyone attempted to confirm if the above is still requried?
It looks like a workaround for an optimisation bug?
To test if this was still a problem, I used the following:
$ /ws/onnv-tools/SUNWspro/SS12/bin/cc -m64 -Ui386 -U__i386 -xO3
-D_ASM_INLINES -Xa -xspace -Wu,-save_args -v -xildoff -g -xc99=%all
-W0,-noglobal -xdebugformat=stabs -errtags=yes -errwarn=%all
-W0,-xglobalstatic -xstrconst -xinline=tcp_set_ws_value -D_SYSCALL32
-D_SYSCALL32_IMPL -D_ELF64 -D_DDI_STRICT -Dsun -D__sun -D__SVR4 foo.c -lnsl
$ ./a.out 1.2.3.4 224.1.1.1 192.168.1.1 129.1.1.1
255.0.0.0
240.0.0.0
255.255.255.0
255.255.0.0
$ cat foo.c
#include <stdio.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#ifdef _BIG_ENDIAN
#define N_IN_CLASSA_NET IN_CLASSA_NET
#define N_IN_CLASSD_NET IN_CLASSD_NET
#define N_INADDR_UNSPEC_GROUP INADDR_UNSPEC_GROUP
#define N_IN_LOOPBACK_NET (ipaddr_t)0x7f000000U
#else /* _BIG_ENDIAN */
#define N_IN_CLASSA_NET (ipaddr_t)0x000000ffU
#define N_IN_CLASSD_NET (ipaddr_t)0x000000f0U
#define N_INADDR_UNSPEC_GROUP (ipaddr_t)0x000000e0U
#define N_IN_LOOPBACK_NET (ipaddr_t)0x0000007fU
#endif /* _BIG_ENDIAN */
#define CLASSD(addr) (((addr) & N_IN_CLASSD_NET) ==
N_INADDR_UNSPEC_GROUP)
#define CLASSE(addr) (((addr) & N_IN_CLASSD_NET) == N_IN_CLASSD_NET)
#define IP_LOOPBACK_ADDR(addr) \
(((addr) & N_IN_CLASSA_NET == N_IN_LOOPBACK_NET))
/*
* Return the network mask
* associated with the specified address.
*/
ipaddr_t
ip_net_mask(ipaddr_t addr)
{
uchar_t *up = (uchar_t *)&addr;
ipaddr_t mask = 0;
uchar_t *maskp = (uchar_t *)&mask;
#if defined(__i386) || defined(__amd64)
#define TOTALLY_BRAIN_DAMAGED_C_COMPILERX
#endif
#ifdef TOTALLY_BRAIN_DAMAGED_C_COMPILER
maskp[0] = maskp[1] = maskp[2] = maskp[3] = 0;
#endif
if (CLASSD(addr)) {
maskp[0] = 0xF0;
return (mask);
}
/* We assume Class E default netmask to be 32 */
if (CLASSE(addr))
return (0xffffffffU);
if (addr == 0)
return (0);
maskp[0] = 0xFF;
if ((up[0] & 0x80) == 0)
return (mask);
maskp[1] = 0xFF;
if ((up[0] & 0xC0) == 0x80)
return (mask);
maskp[2] = 0xFF;
if ((up[0] & 0xE0) == 0xC0)
return (mask);
/* Otherwise return no mask */
return ((ipaddr_t)0);
}
int
main(int argc, char *argv[])
{
struct in_addr ip;
ipaddr_t in;
while (argc > 1) {
inet_pton(AF_INET, argv[1], &in);
ip.s_addr = ip_net_mask(in);
printf("%s\n", inet_ntoa(ip));
argc--;
argv++;
}
return (0);
}
Looks safe for removal... comments on compiling?
Darren
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