From b337acebcc46527c68b365a68aaea0d77ec5ad59 Mon Sep 17 00:00:00 2001
From: Wilson Snyder <wsnyder@wsnyder.org>
Date: Fri, 28 Oct 2011 18:19:04 -0400
Subject: [PATCH] When multiple tops, show example

---
 src/V3LinkCells.cpp | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/V3LinkCells.cpp b/src/V3LinkCells.cpp
index 6b1b72617..74616e81f 100644
--- a/src/V3LinkCells.cpp
+++ b/src/V3LinkCells.cpp
@@ -135,7 +135,15 @@ private:
 		AstNodeModule* modp = vvertexp->modp();
 		modp->level(vvertexp->rank()+1);
 		if (vvertexp == m_topVertexp && modp->level() != 2) {
-		    v3error("Specified --top-module '"<<v3Global.opt.topModule()<<"' isn't at the top level, it's under another cell.");
+		    AstNodeModule* abovep = NULL;
+		    if (V3GraphEdge* edgep = vvertexp->inBeginp()) {
+			if (LinkCellsVertex* eFromVertexp = dynamic_cast<LinkCellsVertex*>(edgep->fromp())) {
+			    abovep = eFromVertexp->modp();
+			}
+		    }
+		    v3error("Specified --top-module '"<<v3Global.opt.topModule()
+			    <<"' isn't at the top level, it's under another cell '"
+			    <<(abovep ? abovep->prettyName() : "UNKNOWN")<<"'");
 		}
 	    }
 	}