Fix code which breaks strict aliasing rule in C language (#990)
Use memcpy() instead of dereferencing a type-punned pointer. This
avoids warnings from the compiler, which indicate it may optimize
the code in a way that results in unexpected behavior.
diff --git a/src/aio/usock_posix.inc b/src/aio/usock_posix.inc
index 0d2f805..1f716b2 100644
--- a/src/aio/usock_posix.inc
+++ b/src/aio/usock_posix.inc
@@ -1085,6 +1085,7 @@
#if defined NN_HAVE_MSG_CONTROL
struct cmsghdr *cmsg;
#endif
+ int fd;
/* If batch buffer doesn't exist, allocate it. The point of delayed
deallocation to allow non-receiving sockets, such as TCP listening
@@ -1152,13 +1153,16 @@
#if defined NN_HAVE_MSG_CONTROL
cmsg = CMSG_FIRSTHDR (&hdr);
while (cmsg) {
- if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) {
+ if (cmsg->cmsg_level == SOL_SOCKET &&
+ cmsg->cmsg_type == SCM_RIGHTS) {
if (self->in.pfd) {
- *self->in.pfd = *((int*) CMSG_DATA (cmsg));
+ memcpy (self->in.pfd, CMSG_DATA (cmsg),
+ sizeof (*self->in.pfd));
self->in.pfd = NULL;
}
else {
- nn_closefd (*((int*) CMSG_DATA (cmsg)));
+ memcpy (&fd, CMSG_DATA (cmsg), sizeof (fd));
+ nn_closefd (fd);
}
break;
}
@@ -1168,11 +1172,13 @@
if (hdr.msg_accrightslen > 0) {
nn_assert (hdr.msg_accrightslen == sizeof (int));
if (self->in.pfd) {
- *self->in.pfd = *((int*) hdr.msg_accrights);
+ memcpy (self->in.pfd, hdr.msg_accrights,
+ sizeof (*self->in.pfd));
self->in.pfd = NULL;
}
else {
- nn_closefd (*((int*) hdr.msg_accrights));
+ memcpy (&fd, hdr.msg_accrights, sizeof (fd));
+ nn_closefd (fd);
}
}
#endif
