From 3d646aa92cdcdf6f42300113227ff5fcfb0a424b Mon Sep 17 00:00:00 2001
From: steve <steve>
Date: Sat, 9 Mar 2002 04:02:26 +0000
Subject: [PATCH]  Constant expressions are not l-values for task ports.

---
 PExpr.h      |  7 ++++++-
 elab_lval.cc | 15 +++++++++++++--
 elaborate.cc | 26 ++++++++++++++++++++++----
 3 files changed, 41 insertions(+), 7 deletions(-)

diff --git a/PExpr.h b/PExpr.h
index 86e0e4df0..e9bc0036d 100644
--- a/PExpr.h
+++ b/PExpr.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: PExpr.h,v 1.55 2002/03/09 02:10:22 steve Exp $"
+#ident "$Id: PExpr.h,v 1.56 2002/03/09 04:02:26 steve Exp $"
 #endif
 
 # include  <string>
@@ -275,6 +275,8 @@ class PENumber : public PExpr {
 				    Link::strength_t drive1) const;
       virtual NetEConst*elaborate_expr(Design*des, NetScope*) const;
       virtual NetExpr*elaborate_pexpr(Design*des, NetScope*sc) const;
+      virtual NetAssign_* elaborate_lval(Design*des, NetScope*scope) const;
+
       virtual verinum* eval_const(const Design*des, const NetScope*sc) const;
       virtual verireal*eval_rconst(const Design*, const NetScope*) const;
 
@@ -473,6 +475,9 @@ class PECallFunction : public PExpr {
 
 /*
  * $Log: PExpr.h,v $
+ * Revision 1.56  2002/03/09 04:02:26  steve
+ *  Constant expressions are not l-values for task ports.
+ *
  * Revision 1.55  2002/03/09 02:10:22  steve
  *  Add the NetUserFunc netlist node.
  *
diff --git a/elab_lval.cc b/elab_lval.cc
index 2ab20f3f9..81fec6c0a 100644
--- a/elab_lval.cc
+++ b/elab_lval.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: elab_lval.cc,v 1.17 2001/12/03 04:47:14 steve Exp $"
+#ident "$Id: elab_lval.cc,v 1.18 2002/03/09 04:02:26 steve Exp $"
 #endif
 
 # include "config.h"
@@ -67,7 +67,7 @@
  */
 NetAssign_* PExpr::elaborate_lval(Design*des, NetScope*scope) const
 {
-      NetNet*ll = elaborate_net(des, scope, 0, 0, 0, 0);
+      NetNet*ll = 0; //XXXXelaborate_net(des, scope, 0, 0, 0, 0);
       if (ll == 0) {
 	    cerr << get_line() << ": Assignment l-value too complex."
 		 << endl;
@@ -275,8 +275,19 @@ NetAssign_* PEIdent::elaborate_lval(Design*des, NetScope*scope) const
       return lv;
 }
 
+NetAssign_* PENumber::elaborate_lval(Design*des, NetScope*) const
+{
+      cerr << get_line() << ": error: Constant values not allowed "
+	   << "in l-value expressions." << endl;
+      des->errors += 1;
+      return 0;
+}
+
 /*
  * $Log: elab_lval.cc,v $
+ * Revision 1.18  2002/03/09 04:02:26  steve
+ *  Constant expressions are not l-values for task ports.
+ *
  * Revision 1.17  2001/12/03 04:47:14  steve
  *  Parser and pform use hierarchical names as hname_t
  *  objects instead of encoded strings.
diff --git a/elaborate.cc b/elaborate.cc
index cfb1bd440..494031550 100644
--- a/elaborate.cc
+++ b/elaborate.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: elaborate.cc,v 1.240 2002/01/23 05:56:22 steve Exp $"
+#ident "$Id: elaborate.cc,v 1.241 2002/03/09 04:02:26 steve Exp $"
 #endif
 
 # include "config.h"
@@ -1487,9 +1487,24 @@ NetProc* PCallTask::elaborate_usr(Design*des, NetScope*scope) const
 	    }
 
 
-	    NetAssign_*lv = parms_[idx]
-		  ? parms_[idx]->elaborate_lval(des, scope)
-		  : 0;
+	      /* Elaborate an l-value version of the port expression
+		 for output and inout ports. If the expression does
+		 not exist then quietly skip it, but if the expression
+		 is not a valid l-value print an error message. Note
+		 that the elaborate_lval method already printed a
+		 detailed message. */
+	    NetAssign_*lv;
+	    if (parms_[idx]) {
+		  lv = parms_[idx]->elaborate_lval(des, scope);
+		  if (lv == 0) {
+			cerr << parms_[idx]->get_line() << ": error: "
+			     << "I give up on task port " << (idx+1)
+			     << " expression: " << *parms_[idx] << endl;
+		  }
+	    } else {
+		  lv = 0;
+	    }
+
 	    if (lv == 0)
 		  continue;
 
@@ -2408,6 +2423,9 @@ Design* elaborate(list<const char*>roots)
 
 /*
  * $Log: elaborate.cc,v $
+ * Revision 1.241  2002/03/09 04:02:26  steve
+ *  Constant expressions are not l-values for task ports.
+ *
  * Revision 1.240  2002/01/23 05:56:22  steve
  *  elaborate deassign lval as done for assign.
  *