Fix class reference with pin that is a class reference (#5454).

Changes

@@ -44,6 +44,7 @@ Verilator 5.029 devel
 * Fix driving clocking block in reactive region (#5430). [Krzysztof Bieganski, Antmicro Ltd.]
 * Fix associative array next/prev/first/last mis-propagating constants (#5435). [Ethan Sifferman]
 * Fix fault on defparam with UNSUPPORTED ignored (#5450). [Luiza de Melo]
+* Fix class reference with pin that is a class reference (#5454).
 
 
 Verilator 5.028 2024-08-21

src/V3LinkDot.cpp

@@ -2414,6 +2414,7 @@ class LinkDotResolveVisitor final : public VNVisitor {
     void visit(AstCell* nodep) override {
         // Cell: Recurse inside or cleanup not founds
         checkNoDot(nodep);
+        VL_RESTORER(m_usedPins);
         m_usedPins.clear();
         UASSERT_OBJ(nodep->modp(), nodep,
                     "Cell has unlinked module");  // V3LinkCell should have errored out
@@ -2443,6 +2444,7 @@ class LinkDotResolveVisitor final : public VNVisitor {
     void visit(AstClassRefDType* nodep) override {
         // Cell: Recurse inside or cleanup not founds
         checkNoDot(nodep);
+        VL_RESTORER(m_usedPins);
         m_usedPins.clear();
         UASSERT_OBJ(nodep->classp(), nodep, "ClassRef has unlinked class");
         UASSERT_OBJ(m_statep->forPrimary() || !nodep->paramsp(), nodep,
@@ -3054,6 +3056,7 @@ class LinkDotResolveVisitor final : public VNVisitor {
     void visit(AstClassOrPackageRef* nodep) override {
         // Class: Recurse inside or cleanup not founds
         // checkNoDot not appropriate, can be under a dot
+        VL_RESTORER(m_usedPins);
         m_usedPins.clear();
         UASSERT_OBJ(m_statep->forPrimary() || VN_IS(nodep->classOrPackageNodep(), ParamTypeDType)
                         || nodep->classOrPackagep(),
@@ -4002,6 +4005,7 @@ class LinkDotResolveVisitor final : public VNVisitor {
             UASSERT_OBJ(ifacep, nodep, "Port parameters of AstIfaceRefDType without ifacep()");
             if (ifacep->dead()) return;
             checkNoDot(nodep);
+            VL_RESTORER(m_usedPins);
             m_usedPins.clear();
             VL_RESTORER(m_pinSymp);
             m_pinSymp = m_statep->getNodeSym(ifacep);

test_regress/t/t_class_ref_ref.py

@@ -0,0 +1,16 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2024 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+import vltest_bootstrap
+
+test.scenarios('linter')
+
+test.lint()
+
+test.passes()

test_regress/t/t_class_ref_ref.v

@@ -0,0 +1,21 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2024 by Wilson Snyder.
+// SPDX-License-Identifier: CC0-1.0
+
+class Cls#(type T = bit);
+endclass
+
+module t(/*AUTOARG*/);
+
+   Cls#(bit) cb;
+
+   Cls#(Cls#(bit)) ccb;
+
+   initial begin
+      $write("*-* All Finished *-*\n");
+      $finish;
+   end
+
+endmodule