Fix passing typedef value as parameter (#6543)

src/V3Param.cpp

@@ -62,6 +62,7 @@
 
 #include <cctype>
 #include <deque>
+#include <map>
 #include <memory>
 #include <vector>
 
@@ -1265,6 +1266,7 @@ public:
 class ParamVisitor final : public VNVisitor {
     // NODE STATE
     // AstNodeModule::user1 -> bool: already fixed level (temporary)
+    // AstNodeDType::user2  -> bool: already visited from typedef
 
     // STATE - across all visitors
     ParamState& m_state;  // Common state
@@ -1279,6 +1281,8 @@ class ParamVisitor final : public VNVisitor {
     // STATE - for current visit position (use VL_RESTORER)
     AstNodeModule* m_modp;  // Module iterating
     string m_generateHierName;  // Generate portion of hierarchy name
+    std::map<const AstRefDType*, bool>
+        m_isCircularTypeCache;  // Caches return values of `V3Width::isCircularType` calls
 
     // METHODS
 
@@ -1413,6 +1417,25 @@ class ParamVisitor final : public VNVisitor {
             processWorkQ();
         }
     }
+    void visit(AstRefDType* nodep) override {
+        const auto iter = m_isCircularTypeCache.find(nodep);
+        bool isCircular;
+        if (iter != m_isCircularTypeCache.end()) {
+            isCircular = iter->second;
+        } else {
+            isCircular = V3Width::isCircularType(nodep);
+            m_isCircularTypeCache.emplace(nodep, isCircular);
+        }
+        if (isCircular) {
+            nodep->v3error("Typedef's type is circular: " << nodep->prettyName());
+        } else if (nodep->typedefp() && nodep->subDTypep()
+                   && (VN_IS(nodep->subDTypep()->skipRefOrNullp(), IfaceRefDType)
+                       || VN_IS(nodep->subDTypep()->skipRefOrNullp(), ClassRefDType))
+                   && !nodep->skipRefp()->user2SetOnce()) {
+            iterate(nodep->skipRefp());
+        }
+        iterateChildren(nodep);
+    }
     void visit(AstCell* nodep) override {
         checkParamNotHier(nodep->paramsp());
         visitCellOrClassRef(nodep, VN_IS(nodep->modp(), Iface));