strace: Fix and enable tracing of msghdr structures.

Useful for sendmsg/recvmsg. However at present it only works for recvmsg,
as sendmsg's parameter is const, and this is not automatically matched.

src/bin/debug/strace/NetworkTypes.cpp

@@ -562,19 +562,6 @@ format_pointer(Context &context, socket_args *args)
 }
 
 
-static string
-get_iovec(Context &context, iovec *iov, int iovlen)
-{
-	if (iov == NULL && iovlen == 0)
-		return "(empty)";
-
-	string r = "{";
-	r += context.FormatPointer(iov);
-	r += ", " + context.FormatSigned(iovlen);
-	return r + "}";
-}
-
-
 static string
 format_pointer(Context &context, message_args *msg)
 {
@@ -587,6 +574,20 @@ format_pointer(Context &context, message_args *msg)
 
 	return r;
 }
+#endif
+
+
+static string
+get_iovec(Context &context, iovec *iov, int iovlen)
+{
+	if (iov == NULL && iovlen == 0)
+		return "(empty)";
+
+	string r = "{";
+	r += context.FormatPointer(iov);
+	r += ", " + context.FormatSigned(iovlen);
+	return r + "}";
+}
 
 
 static string
@@ -605,7 +606,7 @@ format_pointer(Context &context, msghdr *h)
 
 	return r;
 }
-#endif
+
 
 static string
 format_pointer(Context &context, ifreq *ifr)
@@ -710,9 +711,9 @@ POINTER_TYPE(ifconf_ptr, ifconf);
 POINTER_TYPE(ifreq_ptr, ifreq);
 DEFINE_TYPE(pollfd_ptr, pollfd *);
 POINTER_TYPE(siginfo_t_ptr, siginfo_t);
+POINTER_TYPE(msghdr_ptr, msghdr);
 #if 0
 POINTER_TYPE(message_args_ptr, message_args);
-POINTER_TYPE(msghdr_ptr, msghdr);
 POINTER_TYPE(sockaddr_args_ptr, sockaddr_args);
 POINTER_TYPE(sockopt_args_ptr, sockopt_args);
 POINTER_TYPE(socket_args_ptr, socket_args);

src/bin/debug/strace/TypeHandler.h

@@ -101,6 +101,7 @@ struct fd_set;
 struct flock;
 struct ifconf;
 struct ifreq;
+struct msghdr;
 struct message_args;
 struct pollfd;
 struct sockaddr_args;
@@ -111,6 +112,7 @@ DEFINE_FACTORY(fdset_ptr, fd_set *);
 DEFINE_FACTORY(flock_ptr, flock *);
 DEFINE_FACTORY(ifconf_ptr, ifconf *);
 DEFINE_FACTORY(ifreq_ptr, ifreq *);
+DEFINE_FACTORY(msghdr_ptr, msghdr *);
 DEFINE_FACTORY(message_args_ptr, message_args *);
 DEFINE_FACTORY(pollfd_ptr, pollfd *);
 DEFINE_FACTORY(siginfo_t_ptr, siginfo_t *);