Add "no driver for signal bit" error msg to btor back-end

diff --git a/backends/btor/btor.cc b/backends/btor/btor.cc
index 3c5381ce63ebec7b2e01f503876c091cf800950c..61a2f8ba3a3c5e9e6b9d0473d9497a38cd458070 100644 (file)
--- a/backends/btor/btor.cc
+++ b/backends/btor/btor.cc
@@ -775,6 +775,8 @@ struct BtorWorker
                                        }
                                        else
                                        {
+                                               if (bit_cell.count(bit) == 0)
+                                                       log_error("No driver for signal bit %s.\n", log_signal(bit));
                                                export_cell(bit_cell.at(bit));
                                                log_assert(bit_nid.count(bit));
                                        }