Add error for cell output ports that are connected to constants

diff --git a/passes/hierarchy/hierarchy.cc b/passes/hierarchy/hierarchy.cc
index 41c1cfdedba0c414f605ae96eed667c92b512fd2..c460fbbfce158cdd24ed4e4f5609599bfdd2fcde 100644 (file)
--- a/passes/hierarchy/hierarchy.cc
+++ b/passes/hierarchy/hierarchy.cc
@@ -620,34 +620,31 @@ struct HierarchyPass : public Pass {
                        }
                }
 
-               if (!keep_portwidths)
+               for (auto module : design->modules())
+               for (auto cell : module->cells())
                {
-                       for (auto module : design->modules())
-                       for (auto cell : module->cells())
-                       {
-                               if (GetSize(cell->parameters) != 0)
-                                       continue;
-
-                               Module *m = design->module(cell->type);
+                       if (GetSize(cell->parameters) != 0)
+                               continue;
 
-                               if (m == nullptr || m->get_bool_attribute("\\blackbox"))
-                                       continue;
+                       Module *m = design->module(cell->type);
 
-                               for (auto &conn : cell->connections())
-                               {
-                                       Wire *w = m->wire(conn.first);
+                       if (m == nullptr || m->get_bool_attribute("\\blackbox"))
+                               continue;
 
-                                       if (w == nullptr || w->port_id == 0)
-                                               continue;
+                       for (auto &conn : cell->connections())
+                       {
+                               Wire *w = m->wire(conn.first);
 
-                                       if (GetSize(conn.second) == 0)
-                                               continue;
+                               if (w == nullptr || w->port_id == 0)
+                                       continue;
 
-                                       if (GetSize(w) == GetSize(conn.second))
-                                               continue;
+                               if (GetSize(conn.second) == 0)
+                                       continue;
 
-                                       SigSpec sig = conn.second;
+                               SigSpec sig = conn.second;
 
+                               if (!keep_portwidths && GetSize(w) != GetSize(conn.second))
+                               {
                                        if (GetSize(w) < GetSize(conn.second))
                                        {
                                                int n = GetSize(conn.second) - GetSize(w);
@@ -669,6 +666,10 @@ struct HierarchyPass : public Pass {
                                                                log_id(conn.first), GetSize(conn.second), GetSize(sig));
                                        cell->setPort(conn.first, sig);
                                }
+
+                               if (w->port_output && !w->port_input && sig.has_const())
+                                       log_error("Output port %s.%s.%s (%s) is connected to constants: %s\n",
+                                                       log_id(module), log_id(cell), log_id(conn.first), log_id(cell->type), log_signal(sig));
                        }
                }