Improve class extends error format

src/V3LinkDot.cpp

@@ -4769,7 +4769,7 @@ class LinkDotResolveVisitor final : public VNVisitor {
                 } else {
                     nodep->v3warn(E_UNSUPPORTED,
                                   "Unsupported: " << foundp->nodep()->prettyTypeName()
-                                                  << " in AstClassExtends");
+                                                  << " in 'class extends'");
                     return;
                 }
             } else {

test_regress/t/t_class_extends_alias.out

@@ -0,0 +1,5 @@
+%Error-UNSUPPORTED: t/t_class_extends_alias.v:24:21: Unsupported: TYPEDEF 'foo_t' in 'class extends'
+   24 |   class bar extends foo_t;
+      |                     ^~~~~
+                    ... For error description see https://verilator.org/warn/UNSUPPORTED?v=latest
+%Error: Exiting due to

test_regress/t/t_class_extends_alias.v

@@ -0,0 +1,40 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2023 by Antmicro Ltd.
+// SPDX-License-Identifier: CC0-1.0
+
+package pkg;
+endpackage
+
+module t;
+
+  class foo;
+    int x = 1;
+    function int get_x;
+      return x;
+    endfunction
+    function int get_3;
+      return 3;
+    endfunction
+  endclass
+
+  typedef foo foo_t;
+
+  class bar extends foo_t;
+  endclass
+
+  bar bar_foo_t_i;
+
+  initial begin
+    bar_foo_t_i = new;
+    if (bar_foo_t_i.get_x() == 1 && bar_foo_t_i.get_3() == 3) begin
+      $write("*-* All Finished *-*\n");
+      $finish;
+    end
+    else begin
+      $stop;
+    end
+  end
+
+endmodule

test_regress/t/t_class_extends_alias_unsup.out

@@ -1,5 +0,0 @@
-%Error-UNSUPPORTED: t/t_class_extends_alias_unsup.v:22:22: Unsupported: TYPEDEF 'foo_t' in AstClassExtends
-   22 |    class bar extends foo_t;
-      |                      ^~~~~
-                    ... For error description see https://verilator.org/warn/UNSUPPORTED?v=latest
-%Error: Exiting due to

test_regress/t/t_class_extends_alias_unsup.v

@@ -1,38 +0,0 @@
-// DESCRIPTION: Verilator: Verilog Test module
-//
-// This file ONLY is placed under the Creative Commons Public Domain, for
-// any use, without warranty, 2023 by Antmicro Ltd.
-// SPDX-License-Identifier: CC0-1.0
-
-module t (/*AUTOARG*/
-   );
-
-   class foo;
-      int x = 1;
-      function int get_x;
-         return x;
-      endfunction
-      function int get_3;
-         return 3;
-      endfunction
-   endclass
-
-   typedef foo foo_t;
-
-   class bar extends foo_t;
-   endclass
-
-
-   bar bar_foo_t_i;
-
-   initial begin
-      bar_foo_t_i = new;
-      if (bar_foo_t_i.get_x() == 1 && bar_foo_t_i.get_3() == 3) begin
-         $write("*-* All Finished *-*\n");
-         $finish;
-      end
-      else begin
-         $stop;
-      end
-   end
-endmodule

test_regress/t/t_class_extends_pkg_bad.out

@@ -0,0 +1,5 @@
+%Error-UNSUPPORTED: t/t_class_extends_pkg_bad.v:22:21: Unsupported: PACKAGE 'pkg' in 'class extends'
+   22 |   class bar extends pkg;
+      |                     ^~~
+                    ... For error description see https://verilator.org/warn/UNSUPPORTED?v=latest
+%Error: Exiting due to

test_regress/t/t_class_extends_pkg_bad.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(fails=True, expect_filename=test.golden_filename)
+
+test.passes()

test_regress/t/t_class_extends_pkg_bad.v

@@ -0,0 +1,38 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2023 by Antmicro Ltd.
+// SPDX-License-Identifier: CC0-1.0
+
+package pkg;
+endpackage
+
+module t;
+
+  class foo;
+    int x = 1;
+    function int get_x;
+      return x;
+    endfunction
+    function int get_3;
+      return 3;
+    endfunction
+  endclass
+
+  class bar extends pkg;
+  endclass
+
+
+  bar bar_foo_t_i;
+
+  initial begin
+    bar_foo_t_i = new;
+    if (bar_foo_t_i.get_x() == 1 && bar_foo_t_i.get_3() == 3) begin
+      $write("*-* All Finished *-*\n");
+      $finish;
+    end
+    else begin
+      $stop;
+    end
+  end
+endmodule