With -Wpedantic change ASSIGNIN to a warning

docs/guide/exe_verilator.rst

@@ -1530,6 +1530,8 @@ Summary:
    :command:`gcc -Wpedantic`.  Rarely used, and intended only for strict
    compliance tests.
 
+   This option changes :option:`ASSIGNIN` from an error to a warning.
+
 .. option:: -Wwarn-<message>
 
    Enables the specified warning message.

src/V3Options.cpp

@@ -1526,7 +1526,10 @@ void V3Options::parseOptsList(FileLine* fl, const string& optdir, int argc, char
     });
     DECL_OPTION("-vpi", OnOff, &m_vpi);
 
-    DECL_OPTION("-Wpedantic", OnOff, &m_pedantic);
+    DECL_OPTION("-Wpedantic", CbCall, [this]() {
+        m_pedantic = true;
+        V3Error::pretendError(V3ErrorCode::ASSIGNIN, false);
+    });
     DECL_OPTION("-Wall", CbCall, []() {
         FileLine::globalWarnLintOff(false);
         FileLine::globalWarnStyleOff(false);

test_regress/t/t_var_in_assign_pedantic.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 2005 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(vlt => 1);
+
+top_filename("t/t_var_in_assign_bad.v");
+
+lint(
+    verilator_flags2 => ['-Wpedantic -Wno-fatal'],
+    );
+
+ok(1);
+1;