add_guard: skip if no width info available

rtlrepair/analysis.py

@@ -228,7 +228,8 @@ def generic_visit(self, node):
                 # check the lhs first because it might influence the lhs
                 lhs_width = self.expr_width(node.left.var, None)
                 rhs_width = self.expr_width(node.right.var, lhs_width)
-            except RuntimeError:
+            except RuntimeError as e:
+                # print(e)
                 pass  # ignore failure
         elif isinstance(node, vast.IfStatement):
             self.expr_width(node.cond, 1)

rtlrepair/templates/add_guard.py

@@ -43,6 +43,14 @@ def visit_Assign(self, node: vast.Assign):
         # assignments outside of a process
         if self.in_proc:
             return node  # unexpected
+        # Sometimes our with inference algorithm is at wit's end, and we need to skip the node because we do
+        # not know if it will be 1-bit. This generally happens in generate for loops when the induction variable
+        # would need to be known in order to determine the width of an expression. In that case there might
+        # not even be a single with for that particular expression, as the width could be different in each loop
+        # iteration.
+        if node.left.var not in self.a.widths:
+            return node
+
         # check to see if this is a 1-bit assignment
         if self.a.widths[node.left.var] != 1:
             return node