Fix return in constructors (#3734)

src/V3LinkJump.cpp

@@ -234,7 +234,7 @@ private:
             return;
         } else if (!m_ftaskp) {
             nodep->v3error("Return isn't underneath a task or function");
-        } else if (funcp && !nodep->lhsp()) {
+        } else if (funcp && !nodep->lhsp() && !funcp->isConstructor()) {
             nodep->v3error("Return underneath a function should have return value");
         } else if (!funcp && nodep->lhsp()) {
             nodep->v3error("Return underneath a task shouldn't have return value");

test_regress/t/t_class_new_return.pl

@@ -0,0 +1,20 @@
+#!/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 Antmicro Ltd. 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_new_return.v

@@ -0,0 +1,36 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2022 by Antmicro Ltd.
+// SPDX-License-Identifier: CC0-1.0
+
+module t (/*AUTOARG*/
+      clk
+   );
+
+   input clk;
+
+   class foo;
+      int a;
+      function new;
+         a = 1;
+         return;
+         a = 2;
+      endfunction
+      function int get_a;
+         return a;
+      endfunction
+   endclass
+
+   foo foo_i;
+   initial foo_i = new;
+
+   always @(posedge clk) begin
+      if (foo_i.get_a() == 1) begin
+         $write("*-* All Finished *-*\n");
+         $finish;
+      end
+      else
+        $stop;
+   end
+endmodule