From 12728bc4780d737950442b2d009602fbd2d2f246 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Felix=20Neum=C3=A4rker?= <xdch47@posteo.de>
Date: Fri, 3 Mar 2023 18:54:38 -0500
Subject: [PATCH] Fix UNDRIVEN warning seg fault (#3989)

---
 Changes                                       |  1 +
 src/V3Undriven.cpp                            |  3 ++-
 ...ys_comb_multidriven_compile_public_flat.pl | 22 +++++++++++++++++++
 3 files changed, 25 insertions(+), 1 deletion(-)
 create mode 100755 test_regress/t/t_lint_always_comb_multidriven_compile_public_flat.pl

diff --git a/Changes b/Changes
index 4288bef85..0f533c39e 100644
--- a/Changes
+++ b/Changes
@@ -61,6 +61,7 @@ Verilator 5.007 devel
 * Fix subsequent parameter declarations (#3969). [Ryszard Rozak, Antmicro Ltd]
 * Fix timing delays to not truncate below 64 bits (#3973) (#3982). [Felix Neumärker]
 * Fix cmake on macOS to mark weak symbols with -U linker flag (#3978) (#3979). [Peter Debacker]
+* Fix UNDRIVEN warning seg fault (#3989). [Felix Neumärker]
 * Fix packed array structure replication.
 * Fix enum.next(0) and enum.prev(0).
 
diff --git a/src/V3Undriven.cpp b/src/V3Undriven.cpp
index 2b3973ecc..398abf29a 100644
--- a/src/V3Undriven.cpp
+++ b/src/V3Undriven.cpp
@@ -408,7 +408,8 @@ private:
                 }
                 if (entryp->isDrivenWhole() && !m_inBBox && !VN_IS(nodep, VarXRef)
                     && !VN_IS(nodep->dtypep()->skipRefp(), UnpackArrayDType)
-                    && nodep->fileline() != entryp->getNodeFileLinep() && !entryp->isUnderGen()) {
+                    && nodep->fileline() != entryp->getNodeFileLinep() && !entryp->isUnderGen()
+                    && entryp->getNodep()) {
                     if (m_alwaysCombp
                         && (!entryp->isDrivenAlwaysCombWhole()
                             || (entryp->isDrivenAlwaysCombWhole()
diff --git a/test_regress/t/t_lint_always_comb_multidriven_compile_public_flat.pl b/test_regress/t/t_lint_always_comb_multidriven_compile_public_flat.pl
new file mode 100755
index 000000000..9cf2c191e
--- /dev/null
+++ b/test_regress/t/t_lint_always_comb_multidriven_compile_public_flat.pl
@@ -0,0 +1,22 @@
+#!/usr/bin/env perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2023 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_lint_always_comb_multidriven.v");
+
+lint(
+    verilator_flags2 => ['--public-flat-rw --lint-only'],
+    fails => 1,
+    expect_filename => "t/t_lint_always_comb_multidriven.out",
+    );
+
+ok(1);
+1;