From 53695e6729e8ae603be7e7cd9bc8b29758d61a11 Mon Sep 17 00:00:00 2001
From: Bogdan Vukobratovic <bogdan.vukobratovic@gmail.com>
Date: Fri, 14 Jun 2019 11:39:24 +0200
Subject: Prepare for situation when port of the signal cannot be found

---
 kernel/algo.h | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

(limited to 'kernel')

diff --git a/kernel/algo.h b/kernel/algo.h
index 9626c780e..f029ad6ab 100644
--- a/kernel/algo.h
+++ b/kernel/algo.h
@@ -58,10 +58,14 @@ struct Netlist {
 		return sigbit_driver_map.at(sig);
 	}
 
-	RTLIL::SigBit& driver_port(RTLIL::SigBit sig)
+	RTLIL::SigSpec driver_port(RTLIL::SigBit sig)
 	{
 		RTLIL::Cell *cell = driver_cell(sig);
 
+		if (!cell) {
+			return RTLIL::SigSpec();
+		}
+
 		for (auto &port : cell->connections_) {
 			if (ct.cell_output(cell->type, port.first)) {
 				RTLIL::SigSpec port_sig = sigmap(port.second);
@@ -72,6 +76,8 @@ struct Netlist {
 				}
 			}
 		}
+
+		return RTLIL::SigSpec();
 	}
 
 	void setup_netlist(RTLIL::Module *module, const CellTypes &ct)
-- 
cgit v1.2.3