Reviewed by: bde

Changes to support building with _POSIX_SOURCE set to 199309L:

1. Add sys/_posix.h to handle those preprocessor defs that POSIX
says have effects when defined before including any header files;

2. Change POSIX4_VISIBLE back to _POSIX4_VISIBLE

3. Add _POSIX4_VISIBLE_HISTORICALLY for pre-existing BSD features now
defined in POSIX.  These show up when:

_POSIX_SOURCE and _POSIX_C_SOURCE are not set or
_POSIX_C_SOURCE is set >= 199309L

and vanish when:

_POSIX_SOURCE is set or _POSIX_C_SOURCE is < 199309L.

4. Explain these in man 9 posix4;

5. Include _posix.h and conditionalize on new feature test.

7 files changed, 96 insertions, 105 deletions

diff --git a/sys/sys/_posix.h b/sys/sys/_posix.h
new file mode 100644
index 0000000..daf4fe2
--- /dev/null
+++ b/sys/sys/_posix.h
@@ -0,0 +1,73 @@
+#ifndef _SYS__POSIX_H_
+#define _SYS__POSIX_H_
+
+/*-
+ * Copyright (c) 1998 HD Associates, Inc.
+ * All rights reserved.
+ * contact: dufault@hda.com
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	$Id: $
+ */
+
+/*
+ * This is a stand alone header file to set up for feature specification
+ * defined to take place before the inclusion of any standard header.
+ * It should only handle pre-processor defines.
+ *
+ * See section B.2.7 of 1003.1b-1993 
+ *
+ */
+
+#ifndef _POSIX_VERSION
+#define	_POSIX_VERSION		199009L
+#endif
+
+/* Test for visibility of pre-existing POSIX.4 features that should really
+ * be conditional.  If _POSIX_C_SOURCE and _POSIX_SOURCE are not
+ * defined then permit the pre-existing features to show up:
+ */
+#if !defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE)
+#define _POSIX4_VISIBLE_HISTORICALLY
+#endif
+
+/* Test for visibility of additional POSIX.4 features:
+ */
+#if _POSIX_VERSION  >= 199309L && \
+    (!defined(_POSIX_C_SOURCE) || _POSIX_C_SOURCE >= 199309L)
+#define _POSIX4_VISIBLE
+#define _POSIX4_VISIBLE_HISTORICALLY
+#endif
+
+/* I'm not sure if I'm allowed to do this, but at least initially
+ * it may catch some teething problems:
+ */
+
+#if defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE > _POSIX_VERSION)
+#error _POSIX_C_SOURCE > _POSIX_VERSION
+#endif
+
+#define POSIX4_VISIBLE You missed the leading _!!
+#define POSIX4_VISIBLE_FORCEABLY You left the old define in the code!!
+
+#endif /* _SYS__POSIX_H_ */
diff --git a/sys/sys/aio.h b/sys/sys/aio.h
index 4b1604b..09627da 100644
--- a/sys/sys/aio.h
+++ b/sys/sys/aio.h
@@ -16,40 +16,11 @@
  * bad that happens because of using this software isn't the responsibility
  * of the author.  This software is distributed AS-IS.
  *
- * $Id: aio.h,v 1.2 1997/07/17 04:49:43 dyson Exp $
+ * $Id: aio.h,v 1.3 1997/12/08 02:18:14 dyson Exp $
  */
 
 #include <sys/types.h>
 
-/**************************************************************************/
-/* Additions to signal.h -- hack alert.                                   */
-/**************************************************************************/
-/*
- * sigval structure:
- */
-union sigval {
-	int	sival_int;
-	void	*sival_ptr;
-};
-
-/*
- * this is the sigevent structure:
- */
-struct sigevent {
-	int	sigev_notify;		/* Notification */
-	int	sigev_signo;		/* Signal number */
-	union sigval sigev_value;	/* Not used yet in FreeBSD */
-};
-
-/*
- * values for sigev_notify:
- */	
-#define	SIGEV_NONE	0		/* Don't post a signal */
-#define	SIGEV_SIGNAL	1		/* Post specified signal */
-
-/**************************************************************************/
-/* Actual AIO header                                                      */
-/**************************************************************************/
 /*
  * Returned by aio_cancel:
  *  (Note that FreeBSD's aio is not cancellable -- yet.)
@@ -72,11 +43,6 @@ struct sigevent {
 #define	LIO_WAIT		0x1
 
 /*
- * Maximum number of allowed LIO operations
- */
-#define	AIO_LISTIO_MAX		16
-
-/*
  * Private mode bit for aio.
  * (This bit is set by the library routine
  *  to allow the kernel to support sync
diff --git a/sys/sys/mman.h b/sys/sys/mman.h
index f0b609f..764ef35 100644
--- a/sys/sys/mman.h
+++ b/sys/sys/mman.h
@@ -31,12 +31,14 @@
  * SUCH DAMAGE.
  *
  *	@(#)mman.h	8.2 (Berkeley) 1/9/95
- * $Id: mman.h,v 1.20 1997/12/31 01:22:00 alex Exp $
+ * $Id: mman.h,v 1.21 1998/03/04 10:26:35 dufault Exp $
  */
 
 #ifndef _SYS_MMAN_H_
 #define _SYS_MMAN_H_
 
+#include <sys/_posix.h>
+
 /*
  * Protections are chosen from these bits, or-ed together
  */
@@ -63,14 +65,14 @@
 #define	MAP_NOEXTEND	 0x0100	/* for MAP_FILE, don't change file size */
 #define	MAP_HASSEMAPHORE 0x0200	/* region may contain semaphores */
 
-#ifdef POSIX4_VISIBLE
+#ifdef _POSIX4_VISIBLE
 /*
  * Process memory locking
  */
 #define MCL_CURRENT	0x0001	/* Lock only current memory */
 #define MCL_FUTURE	0x0002	/* Lock all future memory as well */
 
-#endif /* POSIX4_VISIBLE */
+#endif /* _POSIX4_VISIBLE */
 
 /*
  * Error return from mmap()
@@ -115,12 +117,12 @@
 #include <sys/cdefs.h>
 
 __BEGIN_DECLS
-#ifdef POSIX4_VISIBLE
+#ifdef _POSIX4_VISIBLE
 int	mlockall __P((int));
 int	munlockall __P((void));
 int	shm_open __P((const char *, int, mode_t));
 int	shm_unlink __P((const char *));
-#endif /* POSIX4_VISIBLE */
+#endif /* _POSIX4_VISIBLE */
 int	mlock __P((const void *, size_t));
 #ifndef _MMAP_DECLARED
 #define	_MMAP_DECLARED
diff --git a/sys/sys/posix4.h b/sys/sys/posix4.h
index 5037b03..99ba882 100644
--- a/sys/sys/posix4.h
+++ b/sys/sys/posix4.h
@@ -33,22 +33,14 @@
  *
  */
 
-#if defined(_POSIX_VERSION) && _POSIX_VERSION >= 199309L
+#include <sys/_posix.h>
+
+#ifdef _POSIX4_VISIBLE
+
 #include <sys/param.h>
 #include <sys/ioccom.h>
 #include <sched.h>
 
-/*
- * This defines POSIX4_VISIBLE to indicate posix4 extensions should show up.
- * You should test this when you add a posix4 extension to a header
- * that exists in POSIX.1.  Try "man 9 posix4".
- */
-
-#if !defined(_POSIX_C_SOURCE) || \
- defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 199309L
-#define POSIX4_VISIBLE
-#endif
-
 /* 
  *
  * March 1, 1998: Details from here on change and this header file
@@ -296,5 +288,5 @@ int kmunlock(int *, void *, const void *, size_t );
 	{ "timer_max", CTLTYPE_INT }, \
 }
 
-#endif /* _POSIX_VERSION >= 199309L */
+#endif /* _POSIX4_VISIBLE */
 #endif /* _POSIX4_POSIX4_H_ */
diff --git a/sys/sys/rtprio.h b/sys/sys/rtprio.h
index 5b6830d..c4a031c 100644
--- a/sys/sys/rtprio.h
+++ b/sys/sys/rtprio.h
@@ -28,7 +28,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: rtprio.h,v 1.4 1997/02/22 09:45:48 peter Exp $
+ *	$Id: rtprio.h,v 1.5 1998/03/04 10:26:39 dufault Exp $
  */
 
 #ifndef _SYS_RTPRIO_H_
@@ -44,23 +44,14 @@
 #define RTP_PRIO_NORMAL		1
 #define RTP_PRIO_IDLE		2
 
-/* RTP_PRIO_FIFO is Posix 4 SCHED_FIFO.
- * Careful: These are based on the kernel config POSIX4 and not
- * the compile time test _POSIX_PRIORITY_SCHEDULING since they
- * set the behavior of the system.
+/* RTP_PRIO_FIFO is POSIX.4 SCHED_FIFO.
  */
 
-#ifdef POSIX4
 #define RTP_PRIO_FIFO_BIT	4
 #define RTP_PRIO_FIFO		(RTP_PRIO_REALTIME | RTP_PRIO_FIFO_BIT)
 #define RTP_PRIO_BASE(P)	((P) & ~RTP_PRIO_FIFO_BIT)
 #define RTP_PRIO_IS_REALTIME(P) (RTP_PRIO_BASE(P) == RTP_PRIO_REALTIME)
 #define RTP_PRIO_NEED_RR(P)	((P) != RTP_PRIO_FIFO)
-#else
-#define RTP_PRIO_BASE(P)	(P)
-#define RTP_PRIO_IS_REALTIME(P)	(P == RTP_PRIO_REALTIME)
-#define RTP_PRIO_NEED_RR(P)	(1)
-#endif
 
 /* priority range */
 #define RTP_PRIO_MIN		0	/* Highest priority */
diff --git a/sys/sys/semaphore.h b/sys/sys/semaphore.h
index fbcab13..a24ac35 100644
--- a/sys/sys/semaphore.h
+++ b/sys/sys/semaphore.h
@@ -36,7 +36,7 @@
  *
  */
 
-#ifdef POSIX4_INCLUDE_MAYBES
+#ifdef _POSIX4_INCLUDE_MAYBES
 #include <sys/types.h>
 #include <fcntl.h>
 #endif
@@ -46,6 +46,7 @@ typedef int sem_t;
 #ifndef KERNEL
 #include <sys/cdefs.h>
 
+__BEGIN_DECLS
 int sem_init __P(sem_t *, int, unsigned int));
 int sem_destroy __P((sem_t *));
 sem_t sem_open __P((const char *, int, ...));
@@ -55,6 +56,7 @@ int sem_wait((sem_t *));
 int sem_trywait((sem_t *));
 int sem_post((sem_t *));
 int sem_getvalue((sem_t *, int *));
+__END_DECLS
 
 #endif /* KERNEL */
 
diff --git a/sys/sys/unistd.h b/sys/sys/unistd.h
index e31a7d3..9ac2c03 100644
--- a/sys/sys/unistd.h
+++ b/sys/sys/unistd.h
@@ -31,12 +31,14 @@
  * SUCH DAMAGE.
  *
  *	@(#)unistd.h	8.2 (Berkeley) 1/7/94
- * $Id: unistd.h,v 1.14 1997/06/16 00:29:26 dyson Exp $
+ * $Id: unistd.h,v 1.15 1998/03/04 10:26:46 dufault Exp $
  */
 
 #ifndef _SYS_UNISTD_H_
 #define	_SYS_UNISTD_H_
 
+#include <sys/_posix.h>
+
 /* compile-time symbolic constants */
 #define	_POSIX_JOB_CONTROL	/* implementation supports job control */
 
@@ -50,47 +52,10 @@
 #define	_POSIX_SAVED_IDS	/* saved set-user-ID and set-group-ID */
 #endif
 
-#ifdef POSIX4
-
-/* Select POSIX.4 regardless.
- * Don't undef first - we want an error on conflicts. 
- */
-
-#define _POSIX_VERSION 199309L
-#endif
-
-#ifndef _POSIX_VERSION
-#define	_POSIX_VERSION		199009L
-#endif
-
-#if _POSIX_VERSION > 199009L
-/*
- * Set it up so that all new headers can assume _POSIX_C_SOURCE is the
- * only thing that must be looked at to determine the feature set,
- * and so that old headers don't have to change:
- */
-#if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE)
-/*
- * Default to latest:
- */
-#define _POSIX_C_SOURCE _POSIX_VERSION
-#endif
-
-#if defined(_POSIX_C_SOURCE) && !defined(_POSIX_SOURCE)
-/*
- * Define _POSIX_SOURCE for older headers:
- */
-#define _POSIX_SOURCE
-#endif
-
 #if _POSIX_VERSION >= 199309L
 #include <posix4/posix4.h>
 #endif
 
-#endif	/* _POSIX_VERSION */
-
-
-
 #define	_POSIX2_VERSION		199212L
 
 /* execution-time symbolic constants */
@@ -162,7 +127,7 @@
 /* configurable system strings */
 #define	_CS_PATH		 1
 
-#ifdef POSIX4_VISIBLE
+#ifdef _POSIX4_VISIBLE
 
 #if 0
 /* Not until the dust settles after the header commit
@@ -205,7 +170,7 @@
 #define _PC_PRIO_IO		54
 #define _PC_SYNC_IO		55
 
-#endif /* POSIX4_VISIBLE */
+#endif /* _POSIX4_VISIBLE */
 
 #ifndef _POSIX_SOURCE
 /*