[git commit master] *: eliminate more aliasing warnings
Denys Vlasenko
vda.linux at googlemail.com
Thu Feb 4 17:41:18 UTC 2010
commit: http://git.busybox.net/busybox/commit/?id=12ca080a1ca8dfd0aeac54485451b906a7e61b16
branch: http://git.busybox.net/busybox/commit/?id=refs/heads/master
Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
include/platform.h | 12 ++++++---
libbb/udp_io.c | 12 +++++-----
networking/ipcalc.c | 44 +++++++++++++++++-------------------
networking/udhcp/arpping.c | 3 +-
util-linux/mkswap.c | 2 +-
util-linux/volume_id/linux_raid.c | 3 +-
6 files changed, 40 insertions(+), 36 deletions(-)
diff --git a/include/platform.h b/include/platform.h
index ab4402e..dcc61a7 100644
--- a/include/platform.h
+++ b/include/platform.h
@@ -201,10 +201,14 @@
* a lvalue. This makes it more likely to not swap them by mistake
*/
#if defined(i386) || defined(__x86_64__)
-# define move_from_unaligned_int(v, intp) ((v) = *(int*)(intp))
-# define move_from_unaligned16(v, u16p) ((v) = *(uint16_t*)(u16p))
-# define move_from_unaligned32(v, u32p) ((v) = *(uint32_t*)(u32p))
-# define move_to_unaligned32(u32p, v) (*(uint32_t*)(u32p) = (v))
+# include <stdint.h>
+typedef int bb__aliased_int FIX_ALIASING;
+typedef uint16_t bb__aliased_uint16_t FIX_ALIASING;
+typedef uint32_t bb__aliased_uint32_t FIX_ALIASING;
+# define move_from_unaligned_int(v, intp) ((v) = *(bb__aliased_int*)(intp))
+# define move_from_unaligned16(v, u16p) ((v) = *(bb__aliased_uint16_t*)(u16p))
+# define move_from_unaligned32(v, u32p) ((v) = *(bb__aliased_uint32_t*)(u32p))
+# define move_to_unaligned32(u32p, v) (*(bb__aliased_uint32_t*)(u32p) = (v))
/* #elif ... - add your favorite arch today! */
#else
/* performs reasonably well (gcc usually inlines memcpy here) */
diff --git a/libbb/udp_io.c b/libbb/udp_io.c
index d9375ea..24237be 100644
--- a/libbb/udp_io.c
+++ b/libbb/udp_io.c
@@ -152,24 +152,24 @@ recv_from_to(int fd, void *buf, size_t len, int flags,
if (cmsgptr->cmsg_level == IPPROTO_IP
&& cmsgptr->cmsg_type == IP_PKTINFO
) {
-# define pktinfo(cmsgptr) ( (struct in_pktinfo*)(CMSG_DATA(cmsgptr)) )
+ const int IPI_ADDR_OFF = offsetof(struct in_pktinfo, ipi_addr);
to->sa_family = AF_INET;
+ /*# define pktinfo(cmsgptr) ( (struct in_pktinfo*)(CMSG_DATA(cmsgptr)) )*/
/*to4->sin_addr = pktinfo(cmsgptr)->ipi_addr; - may be unaligned */
- memcpy(&to4->sin_addr, &pktinfo(cmsgptr)->ipi_addr, sizeof(to4->sin_addr));
+ memcpy(&to4->sin_addr, (char*)(CMSG_DATA(cmsgptr)) + IPI_ADDR_OFF, sizeof(to4->sin_addr));
/*to4->sin_port = 123; - this data is not supplied by kernel */
-# undef pktinfo
break;
}
# if ENABLE_FEATURE_IPV6 && defined(IPV6_PKTINFO)
if (cmsgptr->cmsg_level == IPPROTO_IPV6
&& cmsgptr->cmsg_type == IPV6_PKTINFO
) {
-# define pktinfo(cmsgptr) ( (struct in6_pktinfo*)(CMSG_DATA(cmsgptr)) )
+ const int IPI6_ADDR_OFF = offsetof(struct in6_pktinfo, ipi6_addr);
to->sa_family = AF_INET6;
+ /*# define pktinfo(cmsgptr) ( (struct in6_pktinfo*)(CMSG_DATA(cmsgptr)) )*/
/*to6->sin6_addr = pktinfo(cmsgptr)->ipi6_addr; - may be unaligned */
- memcpy(&to6->sin6_addr, &pktinfo(cmsgptr)->ipi6_addr, sizeof(to6->sin6_addr));
+ memcpy(&to6->sin6_addr, (char*)(CMSG_DATA(cmsgptr)) + IPI6_ADDR_OFF, sizeof(to6->sin6_addr));
/*to6->sin6_port = 123; */
-# undef pktinfo
break;
}
# endif
diff --git a/networking/ipcalc.c b/networking/ipcalc.c
index 18abc12..7855849 100644
--- a/networking/ipcalc.c
+++ b/networking/ipcalc.c
@@ -75,29 +75,34 @@ int get_prefix(unsigned long netmask);
#endif
int ipcalc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int ipcalc_main(int argc, char **argv)
+int ipcalc_main(int argc UNUSED_PARAM, char **argv)
{
unsigned opt;
- int have_netmask = 0;
- in_addr_t netmask, broadcast, network, ipaddr;
- struct in_addr a;
+ bool have_netmask = 0;
+ struct in_addr s_netmask, s_broadcast, s_network, s_ipaddr;
+ /* struct in_addr { in_addr_t s_addr; } and in_addr_t
+ * (which in turn is just a typedef to uint32_t)
+ * are essentially the same type. A few macros for less verbosity: */
+#define netmask (s_netmask.s_addr)
+#define broadcast (s_broadcast.s_addr)
+#define network (s_network.s_addr)
+#define ipaddr (s_ipaddr.s_addr)
char *ipstr;
#if ENABLE_FEATURE_IPCALC_LONG_OPTIONS
applet_long_options = ipcalc_longopts;
#endif
opt = getopt32(argv, "mbn" IF_FEATURE_IPCALC_FANCY("phs"));
- argc -= optind;
argv += optind;
+ if (opt & SILENT)
+ logmode = LOGMODE_NONE; /* suppress error_msg() output */
if (opt & (BROADCAST | NETWORK | NETPREFIX)) {
- if (argc > 2 || argc <= 0)
+ if (!argv[0] || !argv[1] || argv[2])
bb_show_usage();
} else {
- if (argc != 1)
+ if (!argv[0] || argv[1])
bb_show_usage();
}
- if (opt & SILENT)
- logmode = LOGMODE_NONE; /* Suppress error_msg() output */
ipstr = argv[0];
if (ENABLE_FEATURE_IPCALC_FANCY) {
@@ -108,8 +113,7 @@ int ipcalc_main(int argc, char **argv)
while (*prefixstr) {
if (*prefixstr == '/') {
- *prefixstr = (char)0;
- prefixstr++;
+ *prefixstr++ = '\0';
if (*prefixstr) {
unsigned msk;
netprefix = xatoul_range(prefixstr, 0, 32);
@@ -130,42 +134,36 @@ int ipcalc_main(int argc, char **argv)
prefixstr++;
}
}
- ipaddr = inet_aton(ipstr, &a);
- if (ipaddr == 0) {
+ if (inet_aton(ipstr, &s_ipaddr) == 0) {
bb_error_msg_and_die("bad IP address: %s", argv[0]);
}
- ipaddr = a.s_addr;
- if (argc == 2) {
+ if (argv[1]) {
if (ENABLE_FEATURE_IPCALC_FANCY && have_netmask) {
bb_error_msg_and_die("use prefix or netmask, not both");
}
-
- netmask = inet_aton(argv[1], &a);
- if (netmask == 0) {
+ if (inet_aton(argv[1], &s_netmask) == 0) {
bb_error_msg_and_die("bad netmask: %s", argv[1]);
}
- netmask = a.s_addr;
} else {
-
/* JHC - If the netmask wasn't provided then calculate it */
if (!ENABLE_FEATURE_IPCALC_FANCY || !have_netmask)
netmask = get_netmask(ipaddr);
}
if (opt & NETMASK) {
- printf("NETMASK=%s\n", inet_ntoa((*(struct in_addr *) &netmask)));
+ printf("NETMASK=%s\n", inet_ntoa(s_netmask));
}
if (opt & BROADCAST) {
broadcast = (ipaddr & netmask) | ~netmask;
- printf("BROADCAST=%s\n", inet_ntoa((*(struct in_addr *) &broadcast)));
+ printf("BROADCAST=%s\n", inet_ntoa(s_broadcast));
}
if (opt & NETWORK) {
network = ipaddr & netmask;
- printf("NETWORK=%s\n", inet_ntoa((*(struct in_addr *) &network)));
+ printf("NETWORK=%s\n", inet_ntoa(s_network));
}
if (ENABLE_FEATURE_IPCALC_FANCY) {
diff --git a/networking/udhcp/arpping.c b/networking/udhcp/arpping.c
index 548796e..cf18153 100644
--- a/networking/udhcp/arpping.c
+++ b/networking/udhcp/arpping.c
@@ -87,6 +87,7 @@ int FAST_FUNC arpping(uint32_t test_nip,
/* wait for arp reply, and check it */
timeout_ms = 2000;
do {
+ typedef uint32_t aliased_uint32_t FIX_ALIASING;
int r;
unsigned prevTime = monotonic_ms();
@@ -107,7 +108,7 @@ int FAST_FUNC arpping(uint32_t test_nip,
&& arp.operation == htons(ARPOP_REPLY)
/* don't check it: Linux doesn't return proper tHaddr (fixed in 2.6.24?) */
/* && memcmp(arp.tHaddr, from_mac, 6) == 0 */
- && *((uint32_t *) arp.sInaddr) == test_nip
+ && *(aliased_uint32_t*)arp.sInaddr == test_nip
) {
/* if ARP source MAC matches safe_mac
* (which is client's MAC), then it's not a conflict
diff --git a/util-linux/mkswap.c b/util-linux/mkswap.c
index 949c71a..7e32d91 100644
--- a/util-linux/mkswap.c
+++ b/util-linux/mkswap.c
@@ -65,7 +65,7 @@ struct swap_header_v1 {
uint32_t padding[117]; /* 11..127 */
uint32_t badpages[1]; /* 128 */
/* total 129 32-bit words in 2nd kilobyte */
-};
+} FIX_ALIASING;
#define NWORDS 129
#define hdr ((struct swap_header_v1*)bb_common_bufsiz1)
diff --git a/util-linux/volume_id/linux_raid.c b/util-linux/volume_id/linux_raid.c
index d1bf0c3..e1c8636 100644
--- a/util-linux/volume_id/linux_raid.c
+++ b/util-linux/volume_id/linux_raid.c
@@ -44,6 +44,7 @@ struct mdp_super_block {
int FAST_FUNC volume_id_probe_linux_raid(struct volume_id *id /*,uint64_t off*/, uint64_t size)
{
+ typedef uint32_t aliased_uint32_t FIX_ALIASING;
#define off ((uint64_t)0)
uint64_t sboff;
uint8_t uuid[16];
@@ -63,7 +64,7 @@ int FAST_FUNC volume_id_probe_linux_raid(struct volume_id *id /*,uint64_t off*/,
if (mdp->md_magic != cpu_to_le32(MD_MAGIC))
return -1;
- *(uint32_t*)uuid = mdp->set_uuid0;
+ *(aliased_uint32_t*)uuid = mdp->set_uuid0;
memcpy(&uuid[4], &mdp->set_uuid1, 12);
volume_id_set_uuid(id, uuid, UUID_DCE);
--
1.6.3.3
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