Fix associative array default type resolution

src/V3Width.cpp

@@ -5008,7 +5008,10 @@ class WidthVisitor final : public VNVisitor {
     }
     void patternAssoc(AstPattern* nodep, AstAssocArrayDType* arrayDtp, AstPatMember* defaultp) {
         AstNode* defaultValuep = nullptr;
-        if (defaultp) defaultValuep = defaultp->lhssp()->unlinkFrBack();
+        if (defaultp) {
+            defaultp->dtypep(arrayDtp->subDTypep());
+            defaultValuep = patternMemberValueIterate(defaultp);
+        }
         AstNodeExpr* newp = new AstConsAssoc{nodep->fileline(), defaultValuep};
         newp->dtypeFrom(arrayDtp);
         for (AstPatMember* patp = VN_AS(nodep->itemsp(), PatMember); patp;
@@ -5037,7 +5040,10 @@ class WidthVisitor final : public VNVisitor {
     void patternWildcard(AstPattern* nodep, AstWildcardArrayDType* arrayDtp,
                          AstPatMember* defaultp) {
         AstNode* defaultValuep = nullptr;
-        if (defaultp) defaultValuep = defaultp->lhssp()->unlinkFrBack();
+        if (defaultp) {
+            defaultp->dtypep(arrayDtp->subDTypep());
+            defaultValuep = patternMemberValueIterate(defaultp);
+        }
         AstNode* newp = new AstConsWildcard{nodep->fileline(), defaultValuep};
         newp->dtypeFrom(arrayDtp);
         for (AstPatMember* patp = VN_AS(nodep->itemsp(), PatMember); patp;

test_regress/t/t_assoc_default_func.py

@@ -0,0 +1,16 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2025 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_assoc_default_func.v

@@ -0,0 +1,20 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2025 by Wilson Snyder.
+// SPDX-License-Identifier: CC0-1.0
+
+module t;
+  class param_comp #(
+      type T = bit
+  );
+    static function int get_type();
+    endfunction
+  endclass
+
+  class test;
+    virtual function void check_phase();
+      int m_param_comp_bit_expect_wrapper[string] = '{default: param_comp#(bit)::get_type()};
+    endfunction
+  endclass
+endmodule