Add --protect-ids to obscure information in objects, bug1521.

src/V3Ast.cpp

@@ -81,6 +81,7 @@ void AstNode::init() {
     // Attributes
     m_didWidth = false;
     m_doingWidth = false;
+    m_protect = true;
     m_user1u = VNUser(0);
     m_user1Cnt = 0;
     m_user2u = VNUser(0);
@@ -133,6 +134,10 @@ string AstNode::encodeNumber(vlsint64_t num) {
     }
 }
 
+string AstNode::nameProtect() const {
+    return VIdProtect::protectIf(name(), protect());
+}
+
 string AstNode::shortName() const {
     string pretty = name();
     string::size_type pos;