Fix class parameters of enum types (#4219)

src/V3Param.cpp

@@ -307,7 +307,9 @@ class ParamProcessor final : public VNDeleter {
     }
 
     static string paramValueString(const AstNode* nodep) {
-        if (const AstRefDType* const refp = VN_CAST(nodep, RefDType)) { nodep = refp->skipRefp(); }
+        if (const AstRefDType* const refp = VN_CAST(nodep, RefDType)) {
+            nodep = refp->skipRefToEnump();
+        }
         string key = nodep->name();
         if (const AstIfaceRefDType* const ifrtp = VN_CAST(nodep, IfaceRefDType)) {
             if (ifrtp->cellp() && ifrtp->cellp()->modp()) {
@@ -344,7 +346,9 @@ class ParamProcessor final : public VNDeleter {
         // TODO: This parameter value number lookup via a constructed key string is not
         //       particularly robust for type parameters. We should really have a type
         //       equivalence predicate function.
-        if (const AstRefDType* const refp = VN_CAST(nodep, RefDType)) nodep = refp->skipRefp();
+        if (const AstRefDType* const refp = VN_CAST(nodep, RefDType)) {
+            nodep = refp->skipRefToEnump();
+        }
         const string paramStr = paramValueString(nodep);
         // cppcheck-has-bug-suppress unreadVariable
         V3Hash hash = V3Hasher::uncachedHash(nodep) + paramStr;

test_regress/t/t_class_param_enum.pl

@@ -0,0 +1,21 @@
+#!/usr/bin/env perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2022 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
+
+scenarios(simulator => 1);
+
+compile(
+    );
+
+execute(
+    check_finished => 1,
+    );
+
+ok(1);
+1;

test_regress/t/t_class_param_enum.v

@@ -0,0 +1,25 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2023 by Antmicro Ltd.
+// SPDX-License-Identifier: CC0-1.0
+
+typedef enum bit {A = 0, B = 1} enum_t;
+
+class Converter #(type T);
+   function int toInt(T t);
+      return int'(t);
+   endfunction
+endclass
+
+module t;
+   initial begin
+      Converter#(enum_t) conv1 = new;
+      Converter#(bit) conv2 = new;
+      if (conv1.toInt(A) != 0) $stop;
+      if (conv2.toInt(1) != 1) $stop;
+
+      $write("*-* All Finished *-*\n");
+      $finish;
+   end
+endmodule

test_regress/t/t_class_param_enum_bad.out

@@ -0,0 +1,11 @@
+%Error: t/t_class_param_enum_bad.v:20:31: Assign RHS expects a CLASSREFDTYPE 'Converter__Tz2', got CLASSREFDTYPE 'Converter__Tz1'
+                                        : ... In instance t
+   20 |       Converter#(bit) conv2 = conv1;
+      |                               ^~~~~
+%Error-ENUMVALUE: t/t_class_param_enum_bad.v:21:19: Implicit conversion to enum 'T' from 'logic[31:0]' (IEEE 1800-2017 6.19.3)
+                                                  : ... In instance t
+                                                  : ... Suggest use enum's mnemonic, or static cast
+   21 |       conv1.toInt(0);
+      |                   ^
+                  ... For error description see https://verilator.org/warn/ENUMVALUE?v=latest
+%Error: Exiting due to

test_regress/t/t_class_param_enum_bad.pl

@@ -0,0 +1,19 @@
+#!/usr/bin/env perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2022 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
+
+scenarios(simulator => 1);
+
+compile(
+    fails => 1,
+    expect_filename => $Self->{golden_filename},
+    );
+
+ok(1);
+1;

test_regress/t/t_class_param_enum_bad.v

@@ -0,0 +1,24 @@
+// 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
+
+typedef enum bit {A = 0, B = 1} enum_t;
+
+class Converter #(type T);
+   function int toInt(T t);
+      return int'(t);
+   endfunction
+endclass
+
+module t;
+   initial begin
+      Converter#(enum_t) conv1 = new;
+      // enum types does not match with other types (sections 6.22.1 and 6.22.4 of IEEE Std 1800-2017)
+      // The assignment and the function call should throw an error.
+      Converter#(bit) conv2 = conv1;
+      conv1.toInt(0);
+      $stop;
+   end
+endmodule