Verilog: fix nested hierarchical identifiers

Hierarchical identifiers with more than one level now work.

Author: kroening

regression/verilog/hierarchical_identifiers/hierarchical_identifiers1.desc

@@ -0,0 +1,7 @@
+CORE
+hierarchical_identifiers1.v
+--module main --bound 0
+^EXIT=0$
+^SIGNAL=0$
+--
+^warning: ignoring

regression/verilog/hierarchical_identifiers1/main.v renamed to regression/verilog/hierarchical_identifiers/hierarchical_identifiers1.v

@@ -33,6 +33,16 @@ class hierarchical_identifier_exprt : public binary_exprt
     return item();
   }
 
+  const irep_idt &identifier() const
+  {
+    return get(ID_identifier);
+  }
+
+  void identifier(irep_idt _identifier)
+  {
+    set(ID_identifier, _identifier);
+  }
+
 protected:
   using binary_exprt::op0;
   using binary_exprt::op1;

regression/verilog/hierarchical_identifiers1/test.desc

@@ -791,15 +791,20 @@ void verilog_typecheck_exprt::convert_hierarchical_identifier(
 {
   convert_expr(expr.lhs());
 
-  if(expr.lhs().id() != ID_symbol)
-  {
-    throw errort().with_location(expr.source_location())
-      << "expected symbol on lhs of `.'";
-  }
+  const irep_idt &lhs_identifier = [](const exprt &lhs) {
+    if(lhs.id() == ID_symbol)
+      return to_symbol_expr(lhs).get_identifier();
+    else if(lhs.id() == ID_hierarchical_identifier)
+      return to_hierarchical_identifier_expr(lhs).identifier();
+    else
+    {
+      throw errort().with_location(lhs.source_location())
+        << "expected symbol or hierarchical identifier on lhs of `.'";
+    }
+  }(expr.lhs());
 
   DATA_INVARIANT(expr.rhs().id() == ID_symbol, "expected symbol on rhs of `.'");
 
-  const irep_idt &lhs_identifier = to_symbol_expr(expr.lhs()).get_identifier();
   const irep_idt &rhs_identifier = expr.rhs().get_identifier();
 
   irep_idt full_identifier;
@@ -820,6 +825,8 @@ void verilog_typecheck_exprt::convert_hierarchical_identifier(
     full_identifier=
       id2string(module)+"."+id2string(rhs_identifier);
 
+    expr.identifier(full_identifier);
+
     const symbolt *symbol;
     if(!ns.lookup(full_identifier, symbol))
     {