From 741b17245da9b9480aa6ec870584af22fc0380c0 Mon Sep 17 00:00:00 2001
From: steve <steve>
Date: Sun, 16 Jul 2000 04:56:07 +0000
Subject: [PATCH]  Handle some edge cases during node scans.

---
 functor.cc    | 25 +++++++++++++++++++++++--
 functor.h     | 12 +++++++++++-
 net_design.cc |  6 +++++-
 netlist.h     |  6 +++++-
 4 files changed, 44 insertions(+), 5 deletions(-)

diff --git a/functor.cc b/functor.cc
index 0492f2024..b881f4849 100644
--- a/functor.cc
+++ b/functor.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: functor.cc,v 1.19 2000/07/15 05:13:43 steve Exp $"
+#ident "$Id: functor.cc,v 1.20 2000/07/16 04:56:07 steve Exp $"
 #endif
 
 # include  "functor.h"
@@ -110,12 +110,30 @@ void Design::functor(functor_t*fun)
 
 	// apply to nodes
       if (nodes_) {
+	      /* Scan the circular list of nodes, starting with the
+		 front of the list. (nodes_ points to the *end* of the
+		 list.) The bar is the end point. At the end of the
+		 do-while loop, I know that the bar has been
+		 processed or (if bar == 0) no undeleted node has been
+		 processed. */
 	    NetNode*cur = nodes_->node_next_;
+	    NetNode*bar = 0;
 	    do {
 		  NetNode*tmp = cur->node_next_;
 		  cur->functor_node(this, fun);
+
+		    /* Detect the case that cur has been deleted by
+		       noticing if tmp->node_prev_ no longer points to
+		       cur. If that's the case, clear the bar. */
+		  if (tmp->node_prev_ != cur) {
+			if (cur == bar)
+			      bar = 0;
+		  } else if (bar == 0) {
+			bar = cur;
+		  }
 		  cur = tmp;
-	    } while (nodes_ && cur != nodes_->node_next_);
+
+	    } while (nodes_ && (cur != bar));
       }
 }
 
@@ -227,6 +245,9 @@ int proc_match_t::event_wait(NetEvWait*)
 
 /*
  * $Log: functor.cc,v $
+ * Revision 1.20  2000/07/16 04:56:07  steve
+ *  Handle some edge cases during node scans.
+ *
  * Revision 1.19  2000/07/15 05:13:43  steve
  *  Detect muxing Vz as a bufufN.
  *
diff --git a/functor.h b/functor.h
index bc3090acf..c08b5b3f9 100644
--- a/functor.h
+++ b/functor.h
@@ -19,13 +19,20 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: functor.h,v 1.14 2000/07/15 05:13:44 steve Exp $"
+#ident "$Id: functor.h,v 1.15 2000/07/16 04:56:07 steve Exp $"
 #endif
 
 /*
  * The functor is an object that can be applied to a design to
  * transform it. This is different from the target_t, which can only
  * scan the design but not transform it in any way.
+ *
+ * When a functor it scanning a process, signal or node, the functor
+ * is free to manipulate the list by deleting items, including the
+ * node being scanned. The Design class scanner knows how to handle
+ * the situation. However, if objects are added to the netlist, there
+ * is no guarantee that object will be scanned unless the functor is
+ * rerun.
  */
 
 class Design;
@@ -82,6 +89,9 @@ struct proc_match_t {
 
 /*
  * $Log: functor.h,v $
+ * Revision 1.15  2000/07/16 04:56:07  steve
+ *  Handle some edge cases during node scans.
+ *
  * Revision 1.14  2000/07/15 05:13:44  steve
  *  Detect muxing Vz as a bufufN.
  *
diff --git a/net_design.cc b/net_design.cc
index ae4415753..1f82b80ad 100644
--- a/net_design.cc
+++ b/net_design.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: net_design.cc,v 1.9 2000/07/14 06:12:57 steve Exp $"
+#ident "$Id: net_design.cc,v 1.10 2000/07/16 04:56:08 steve Exp $"
 #endif
 
 /*
@@ -46,6 +46,7 @@ static string parse_last_name(string&path)
 Design:: Design()
 : errors(0), root_scope_(0), nodes_(0), procs_(0), lcounter_(0)
 {
+      procs_idx_ = 0;
 }
 
 Design::~Design()
@@ -470,6 +471,9 @@ void Design::delete_process(NetProcTop*top)
 
 /*
  * $Log: net_design.cc,v $
+ * Revision 1.10  2000/07/16 04:56:08  steve
+ *  Handle some edge cases during node scans.
+ *
  * Revision 1.9  2000/07/14 06:12:57  steve
  *  Move inital value handling from NetNet to Nexus
  *  objects. This allows better propogation of inital
diff --git a/netlist.h b/netlist.h
index 58decd43f..375edc900 100644
--- a/netlist.h
+++ b/netlist.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: netlist.h,v 1.146 2000/07/15 05:13:44 steve Exp $"
+#ident "$Id: netlist.h,v 1.147 2000/07/16 04:56:08 steve Exp $"
 #endif
 
 /*
@@ -266,6 +266,7 @@ class NetNode  : public NetObj {
       virtual void emit_node(ostream&, struct target_t*) const;
       virtual void dump_node(ostream&, unsigned) const;
 
+	// This is used to scan a modifiable netlist, one node at a time.
       virtual void functor_node(Design*, functor_t*);
 
     private:
@@ -2659,6 +2660,9 @@ extern ostream& operator << (ostream&, NetNet::Type);
 
 /*
  * $Log: netlist.h,v $
+ * Revision 1.147  2000/07/16 04:56:08  steve
+ *  Handle some edge cases during node scans.
+ *
  * Revision 1.146  2000/07/15 05:13:44  steve
  *  Detect muxing Vz as a bufufN.
  *