From c92b37b1bdb08b3a3b5c5b3c670090f80cc8eb8d Mon Sep 17 00:00:00 2001
From: Stephen Williams <steve@icarus.com>
Date: Tue, 4 Sep 2007 16:26:43 -0700
Subject: [PATCH] Error message for inconnected primitive ports.

Error message (instead of a seg fault) when a primitive port
is left unconnected.

Signed-off-by: Stephen Williams <steve@icarus.com>
---
 elaborate.cc | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/elaborate.cc b/elaborate.cc
index 50734d53df..45d737ff73 100644
--- a/elaborate.cc
+++ b/elaborate.cc
@@ -469,6 +469,12 @@ void PGBuiltin::elaborate(Design*des, NetScope*scope) const
 
       for (unsigned idx = 0 ;  idx < pin_count() ;  idx += 1) {
 	    const PExpr*ex = pin(idx);
+	    if (ex == 0) {
+		  cerr << get_line() << ": error: Logic gate port "
+			"expressions are not optional." << endl;
+		  des->errors += 1;
+		  return;
+	    }
 	    NetNet*sig = (idx == 0)
 		  ? ex->elaborate_lnet(des, scope, true)
 		  : ex->elaborate_net(des, scope, 0, 0, 0, 0);