Imported Upstream version 93u+upstream

1 files changed, 157 insertions, 0 deletions

diff --git a/src/lib/libast/cdt/dtview.c b/src/lib/libast/cdt/dtview.c
new file mode 100644
index 0000000..94f4a54
--- /dev/null
+++ b/src/lib/libast/cdt/dtview.c
@@ -0,0 +1,157 @@
+/***********************************************************************
+*                                                                      *
+*               This software is part of the ast package               *
+*          Copyright (c) 1985-2011 AT&T Intellectual Property          *
+*                      and is licensed under the                       *
+*                 Eclipse Public License, Version 1.0                  *
+*                    by AT&T Intellectual Property                     *
+*                                                                      *
+*                A copy of the License is available at                 *
+*          http://www.eclipse.org/org/documents/epl-v10.html           *
+*         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
+*                                                                      *
+*              Information and Software Systems Research               *
+*                            AT&T Research                             *
+*                           Florham Park NJ                            *
+*                                                                      *
+*                 Glenn Fowler <gsf@research.att.com>                  *
+*                  David Korn <dgk@research.att.com>                   *
+*                   Phong Vo <kpv@research.att.com>                    *
+*                                                                      *
+***********************************************************************/
+#include	"dthdr.h"
+
+/*	Set a view path from dict to view.
+**
+**	Written by Kiem-Phong Vo (5/25/96)
+*/
+
+/* these operations must be done without viewpathing */
+#define DT_NOVIEWPATH	(DT_INSERT|DT_APPEND|DT_DELETE|\
+			 DT_ATTACH|DT_DETACH|DT_RELINK|DT_CLEAR| \
+			 DT_FLATTEN|DT_EXTRACT|DT_RESTORE|DT_STAT)
+
+#if __STD_C
+static Void_t* dtvsearch(Dt_t* dt, reg Void_t* obj, reg int type)
+#else
+static Void_t* dtvsearch(dt,obj,type)
+Dt_t*		dt;
+reg Void_t*	obj;
+reg int		type;
+#endif
+{
+	int		cmp;
+	Dt_t		*d, *p;
+	Void_t		*o, *n, *oky, *nky;
+
+	if(type&DT_NOVIEWPATH)
+		return (*(dt->meth->searchf))(dt,obj,type);
+
+	o = NIL(Void_t*);
+
+	/* these ops look for the first appearance of an object of the right type */
+	if((type & (DT_MATCH|DT_SEARCH)) ||
+	   ((type & (DT_FIRST|DT_LAST|DT_ATLEAST|DT_ATMOST)) && !(dt->meth->type&DT_ORDERED) ) )
+	{	for(d = dt; d; d = d->view)
+			if((o = (*(d->meth->searchf))(d,obj,type)) )
+				break;
+		dt->walk = d;
+		return o;
+	}
+
+	if(dt->meth->type & DT_ORDERED) /* ordered sets/bags */
+	{	if(!(type & (DT_FIRST|DT_LAST|DT_NEXT|DT_PREV|DT_ATLEAST|DT_ATMOST)) )
+			return NIL(Void_t*);
+
+		/* find the min/max element that satisfies the op requirement */
+		n = nky = NIL(Void_t*); p = NIL(Dt_t*);
+		for(d = dt; d; d = d->view)
+		{	if(!(o = (*d->meth->searchf)(d, obj, type)) )
+				continue;
+			oky = _DTKEY(d->disc,o);
+
+			if(n) /* get the right one among all dictionaries */
+			{	cmp = _DTCMP(d,oky,nky,d->disc);
+				if(((type & (DT_NEXT|DT_FIRST|DT_ATLEAST)) && cmp < 0) ||
+				   ((type & (DT_PREV|DT_LAST|DT_ATMOST)) && cmp > 0) )
+					goto b_est;
+			}
+			else
+			{ b_est: /* current best element to fit op requirement */
+				p  = d;
+				n  = o;
+				nky = oky;
+			}
+		}
+
+		dt->walk = p;
+		return n;
+	}
+
+	/* unordered collections */
+	if(!(type&(DT_NEXT|DT_PREV)) )
+		return NIL(Void_t*);
+
+	if(!dt->walk )
+	{	for(d = dt; d; d = d->view)
+			if((o = (*(d->meth->searchf))(d, obj, DT_SEARCH)) )
+				break;
+		dt->walk = d;
+		if(!(obj = o) )
+			return NIL(Void_t*);
+	}
+
+	for(d = dt->walk, obj = (*d->meth->searchf)(d, obj, type);; )
+	{	while(obj) /* keep moving until finding an uncovered object */
+		{	for(p = dt; ; p = p->view)
+			{	if(p == d) /* adjacent object is uncovered */	
+					return obj;
+				if((*(p->meth->searchf))(p, obj, DT_SEARCH) )
+					break;
+			}
+			obj = (*d->meth->searchf)(d, obj, type);
+		}
+
+		if(!(d = dt->walk = d->view) ) /* move on to next dictionary */
+			return NIL(Void_t*);
+		else if(type&DT_NEXT)
+			obj = (*(d->meth->searchf))(d,NIL(Void_t*),DT_FIRST);
+		else	obj = (*(d->meth->searchf))(d,NIL(Void_t*),DT_LAST);
+	}
+}
+
+#if __STD_C
+Dt_t* dtview(reg Dt_t* dt, reg Dt_t* view)
+#else
+Dt_t* dtview(dt,view)
+reg Dt_t*	dt;
+reg Dt_t*	view;
+#endif
+{
+	reg Dt_t*	d;
+
+	if(view && view->meth != dt->meth) /* must use the same method */
+		return NIL(Dt_t*);
+
+	/* make sure there won't be a cycle */
+	for(d = view; d; d = d->view)
+		if(d == dt)
+			return NIL(Dt_t*);
+
+	/* no more viewing lower dictionary */
+	if((d = dt->view) )
+		d->nview -= 1;
+	dt->view = dt->walk = NIL(Dt_t*);
+
+	if(!view)
+	{	dt->searchf = dt->meth->searchf;
+		return d;
+	}
+
+	/* ok */
+	dt->view = view;
+	dt->searchf = dtvsearch;
+	view->nview += 1;
+
+	return view;
+}