[#99211] Static virtual ftasks detection

Signed-off-by: Igor Zaworski <izaworski@antmicro.com>

src/V3Task.cpp

@@ -1740,6 +1740,10 @@ class TaskVisitor final : public VNVisitor {
                                << nodep->prettyNameQ());
             }
 
+            if (nodep->isStatic() && nodep->isVirtual()) {
+                nodep->v3error("Static methods cannot be virtual");
+            }
+
             const bool noInline = m_statep->ftaskNoInline(nodep);
             const bool needsNonInlineCFunc = m_statep->ftaskNeedsNonInlineCFunc(nodep);
             // Warn if not inlining an impure ftask (unless method, recursive,

test_regress/t/t_class_static_virtual_method_bad.out

@@ -0,0 +1,6 @@
+%Error: t/t_class_static_virtual_method_bad.v:8:23: Static methods cannot be virtual
+                                                  : ... note: In instance '$unit.Foo'
+    8 |   static virtual task foo(); endtask
+      |                       ^~~
+        ... See the manual at https://verilator.org/verilator_doc.html?v=latest for more assistance.
+%Error: Exiting due to

test_regress/t/t_class_static_virtual_method_bad.py

@@ -0,0 +1,16 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# 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-FileCopyrightText: 2026 Wilson Snyder
+# 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_static_virtual_method_bad.v

@@ -0,0 +1,9 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain.
+// SPDX-FileCopyrightText: 2026 Antmicro
+// SPDX-License-Identifier: CC0-1.0
+
+class Foo;
+  static virtual task foo(); endtask
+endclass