fix dependency on ADVANCED_REALTIME

Do not depend on ADVANCED REALTIME for mq_send/mq_receive
Added stubs implementation based on libc's stubs.c

Signed-off-by: Peter S. Mazinger <ps.m@gmx.net>

librt/mq_receive.c

@@ -2,22 +2,23 @@
  * mq_receive.c - functions for receiving from message queue.
  */
 
-#include <errno.h>
-#include <stddef.h>
 #include <sys/syscall.h>
+
+#ifdef __NR_mq_timedreceive
+
+#include <stddef.h>
 #include <mqueue.h>
-#warning FIXME: hard dependency on ADVANCED REALTIME feature
 
+#ifdef __UCLIBC_HAS_THREADS_NATIVE__
 librt_hidden_proto(mq_timedreceive)
+#else
 
-#ifndef __UCLIBC_HAS_THREADS_NATIVE__
-#ifdef __NR_mq_timedreceive
-#define __NR___syscall_mq_timedreceive __NR_mq_timedreceive
-static __inline__ _syscall5(int, __syscall_mq_timedreceive, int, mqdes,
-			char *, msg_ptr, size_t, msg_len, unsigned int *,
-			msg_prio, const void *, abs_timeout);
-#endif
+# define __NR___syscall_mq_timedreceive __NR_mq_timedreceive
+static _syscall5(int, __syscall_mq_timedreceive, int, mqdes,
+		 char *, msg_ptr, size_t, msg_len, unsigned int *,
+		 msg_prio, const void *, abs_timeout);
 
+# ifdef __UCLIBC_HAS_ADVANCED_REALTIME__
 /*
  * Receive the oldest from highest priority messages.
  * Stop waiting if abs_timeout expires.
@@ -26,21 +27,22 @@ ssize_t mq_timedreceive(mqd_t mqdes, char *msg_ptr, size_t msg_len,
 			unsigned int *msg_prio,
 			const struct timespec *abs_timeout)
 {
-#ifdef __NR_mq_timedreceive
 	return __syscall_mq_timedreceive(mqdes, msg_ptr, msg_len, msg_prio,
 					 abs_timeout);
-#else
-	errno = ENOSYS;
-	return -1;
-#endif
 }
+# endif
 
-librt_hidden_def(mq_timedreceive)
 #endif
 
 /* Receive the oldest from highest priority messages */
 ssize_t mq_receive(mqd_t mqdes, char *msg_ptr, size_t msg_len,
 		   unsigned int *msg_prio)
 {
+#ifdef __UCLIBC_HAS_THREADS_NATIVE__
 	return mq_timedreceive(mqdes, msg_ptr, msg_len, msg_prio, NULL);
+#else
+	return __syscall_mq_timedreceive(mqdes, msg_ptr, msg_len, msg_prio, NULL);
+#endif
 }
+
+#endif

librt/mq_send.c

@@ -2,22 +2,23 @@
  * mq_send.c - functions for sending to message queue.
  */
 
-#include <errno.h>
-#include <stddef.h>
 #include <sys/syscall.h>
+
+#ifdef __NR_mq_timedsend
+
+#include <stddef.h>
 #include <mqueue.h>
-#warning FIXME: hard dependency on ADVANCED REALTIME feature
 
+#ifdef __UCLIBC_HAS_THREADS_NATIVE__
 librt_hidden_proto(mq_timedsend)
+#else
 
-#ifndef __UCLIBC_HAS_THREADS_NATIVE__
-#ifdef __NR_mq_timedsend
-#define __NR___syscall_mq_timedsend __NR_mq_timedsend
-static __inline__ _syscall5(int, __syscall_mq_timedsend, int, mqdes,
-			const char *, msg_ptr, size_t, msg_len, unsigned int,
-			msg_prio, const void *, abs_timeout);
-#endif
+# define __NR___syscall_mq_timedsend __NR_mq_timedsend
+static _syscall5(int, __syscall_mq_timedsend, int, mqdes,
+		 const char *, msg_ptr, size_t, msg_len, unsigned int,
+		 msg_prio, const void *, abs_timeout);
 
+# ifdef __UCLIBC_HAS_ADVANCED_REALTIME__
 /*
  * Add a message to queue. If O_NONBLOCK is set and queue is full, wait
  * for sufficient room in the queue until abs_timeout expires.
@@ -25,21 +26,21 @@ static __inline__ _syscall5(int, __syscall_mq_timedsend, int, mqdes,
 int mq_timedsend(mqd_t mqdes, const char *msg_ptr, size_t msg_len,
 		 unsigned int msg_prio, const struct timespec *abs_timeout)
 {
-#ifdef __NR_mq_timedsend
 	return __syscall_mq_timedsend(mqdes, msg_ptr, msg_len, msg_prio,
 				      abs_timeout);
-#else
-	errno = ENOSYS;
-	return -1;
-#endif
 }
-
-librt_hidden_def(mq_timedsend)
+# endif
 #endif
 
 /* Add a message to queue */
 int mq_send(mqd_t mqdes, const char *msg_ptr, size_t msg_len,
 	    unsigned int msg_prio)
 {
+#ifdef __UCLIBC_HAS_THREADS_NATIVE__
 	return mq_timedsend(mqdes, msg_ptr, msg_len, msg_prio, NULL);
+#else
+	return __syscall_mq_timedsend(mqdes, msg_ptr, msg_len, msg_prio, NULL);
+#endif
 }
+
+#endif

librt/rt_stubs.c

@@ -0,0 +1,39 @@
+/*
+ * system call not available stub
+ * based on libc's stubs.c
+ *
+ * Copyright (C) 2009 Analog Devices Inc.
+ *
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ */
+
+#include <errno.h>
+#include <sys/syscall.h>
+
+#ifdef __UCLIBC_HAS_STUBS__
+
+static int rt_enosys_stub(void)
+{
+	__set_errno(ENOSYS);
+	return -1;
+}
+
+#define make_stub(stub) \
+	link_warning(stub, #stub ": this function is not implemented") \
+	strong_alias(rt_enosys_stub, stub)
+
+#ifndef __NR_mq_timedreceive
+make_stub(mq_receive)
+# ifdef __UCLIBC_HAS_ADVANCED_REALTIME__
+make_stub(mq_timedreceive)
+# endif
+#endif
+
+#ifndef __NR_mq_timedsend
+make_stub(mq_send)
+# ifdef __UCLIBC_HAS_ADVANCED_REALTIME__
+make_stub(mq_timedsend)
+# endif
+#endif
+
+#endif