swab() in string.h

[Geoffrey Keating]

Having swab() in string.h means we need to drag in ssize_t, or
something similar.  The SVID doesn't specify a header file; XPG says
<unistd.h>.  GLibc defines it in <unistd.h> only, Solaris defines it
in <stdlib.h> and <unistd.h>, AIX defines it in <string.h> (only if
_ALL_SOURCE) and <unistd.h>.  HPUX defines it in <unistd.h>, or in
<string.h> only if _INCLUDE_AES_SOURCE is defined.

So in short I think it'd be better if we didn't define it in
<string.h>.  GCC knows about its prototype anyway, so this should not
cause any problems.  This lets us remove <sys/types.h> from
<string.h>.

Oh, and the doc is certainly wrong.  No-one should be expecting it in
string.h, even if it's there.  The Solaris, AIX, and HPUX manual pages
all say <unistd.h>.

(The reason for all this is that a customer was complaining that
including <string.h> caused, among other things, time_t and fdset_t to
be defined, a particularly nasty bit of namespace pollution especially
as the customer was using their own I/O library and only wanted the
string routines from newlib.)

OK to commit?

-- 
Geoff Keating <geoffk@cygnus.com>

===File ~/patches/newlib-swab.patch=========================
2000-08-29  Geoffrey Keating  <geoffk@cygnus.com>

	* libc/string/swab.c: Specify that it's defined in <unistd.h>.
	* libc/include/string.h: Don't include <sys/types.h>,
	as it causes really bad namespace pollution.  Don't declare
	swab(), it is properly declared in unistd.h.

Index: libc/include/string.h
===================================================================
RCS file: /cvs/src/src/newlib/libc/include/string.h,v
retrieving revision 1.7
diff -u -p -r1.7 string.h
--- string.h	2000/06/03 03:03:03	1.7
+++ string.h	2000/08/30 03:54:12
@@ -13,7 +13,6 @@ extern "C" {
 
 #include "_ansi.h"
 #include <sys/reent.h>
-#include <sys/types.h>
 
 #define __need_size_t
 #include <stddef.h>
@@ -72,7 +71,6 @@ const char  *_EXFUN(strsignal, (int __si
 #endif
 int     _EXFUN(strtosigno, (const char *__name));
 #endif
-void	 _EXFUN(swab,(const void *, void *, ssize_t));
 
 /* These function names are used on Windows and perhaps other systems.  */
 #ifndef strcmpi
Index: libc/string/swab.c
===================================================================
RCS file: /cvs/src/src/newlib/libc/string/swab.c,v
retrieving revision 1.3
diff -u -p -r1.3 swab.c
--- swab.c	2000/03/09 22:25:01	1.3
+++ swab.c	2000/08/30 03:54:13
@@ -3,7 +3,7 @@ FUNCTION
 	<<swab>>---swap adjacent bytes
 
 ANSI_SYNOPSIS
-	#include <string.h>
+	#include <unistd.h>
 	void swab(const void *<[in]>, void *<[out]>, ssize_t <[n]>);
 
 TRAD_SYNOPSIS
============================================================