From 8b647f09775b3a1e2153f9ab956ffaf5fa4ad9be Mon Sep 17 00:00:00 2001
From: Wilson Snyder <wsnyder@wsnyder.org>
Date: Tue, 2 Jun 2020 08:00:37 -0400
Subject: [PATCH] Fix error on UNPACKED in parser. (#1541)

---
 bin/verilator                         |  5 ++++-
 src/verilog.y                         |  2 +-
 test_regress/t/t_struct_unpacked2.out |  8 ++++++++
 test_regress/t/t_struct_unpacked2.pl  | 19 +++++++++++++++++++
 test_regress/t/t_struct_unpacked2.v   | 21 +++++++++++++++++++++
 5 files changed, 53 insertions(+), 2 deletions(-)
 create mode 100644 test_regress/t/t_struct_unpacked2.out
 create mode 100755 test_regress/t/t_struct_unpacked2.pl
 create mode 100644 test_regress/t/t_struct_unpacked2.v

diff --git a/bin/verilator b/bin/verilator
index cd0f84583..b8d345107 100755
--- a/bin/verilator
+++ b/bin/verilator
@@ -4816,7 +4816,10 @@ correctly.
 Warns that unpacked structs and unions are not supported.
 
 Ignoring this warning will make Verilator treat the structure as packed,
-which may make Verilator simulations differ from other simulators.
+which may make Verilator simulations differ from other simulators. This
+downgrading may also result what would normally be a legal unpacked
+struct/array inside an unpacked struct/array becomming an illegal unpacked
+struct/array inside a packed struct/array.
 
 =item UNSIGNED
 
diff --git a/src/verilog.y b/src/verilog.y
index 2d3bf6475..5a778c838 100644
--- a/src/verilog.y
+++ b/src/verilog.y
@@ -1667,7 +1667,7 @@ list_of_member_decl_assignments<nodep>:	// Derived from IEEE: list_of_variable_d
 member_decl_assignment<memberp>:	// Derived from IEEE: variable_decl_assignment
 	//			// At present we allow only packed structures/unions.  So this is different from variable_decl_assignment
 		id variable_dimensionListE
-			{ if ($2) $2->v3error("Unsupported: Unpacked array in packed struct/union");
+			{ if ($2) $2->v3warn(UNPACKED, "Unsupported: Unpacked array in packed struct/union (struct/union converted to unpacked)");
 			  $$ = new AstMemberDType($<fl>1, *$1, VFlagChildDType(),
 						  AstNodeDType::cloneTreeNull(GRAMMARP->m_memDTypep, true));
                           PARSEP->tagNodep($$);
diff --git a/test_regress/t/t_struct_unpacked2.out b/test_regress/t/t_struct_unpacked2.out
new file mode 100644
index 000000000..3d938df82
--- /dev/null
+++ b/test_regress/t/t_struct_unpacked2.out
@@ -0,0 +1,8 @@
+%Warning-UNPACKED: t/t_struct_unpacked2.v:10:13: Unsupported: Unpacked array in packed struct/union (struct/union converted to unpacked)
+   10 |       int b [2];
+      |             ^
+                   ... Use "/* verilator lint_off UNPACKED */" and lint_on around source to disable this message.
+%Warning-UNPACKED: t/t_struct_unpacked2.v:9:12: Unsupported: Unpacked struct/union
+    9 |    typedef struct {
+      |            ^~~~~~
+%Error: Exiting due to
diff --git a/test_regress/t/t_struct_unpacked2.pl b/test_regress/t/t_struct_unpacked2.pl
new file mode 100755
index 000000000..59ba0d6c6
--- /dev/null
+++ b/test_regress/t/t_struct_unpacked2.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 2003 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(linter => 1);
+
+lint(
+    fails => $Self->{vlt_all},
+    expect_filename => $Self->{golden_filename},
+    );
+
+ok(1);
+1;
diff --git a/test_regress/t/t_struct_unpacked2.v b/test_regress/t/t_struct_unpacked2.v
new file mode 100644
index 000000000..e7c6ff9ff
--- /dev/null
+++ b/test_regress/t/t_struct_unpacked2.v
@@ -0,0 +1,21 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2009 by Wilson Snyder.
+// SPDX-License-Identifier: CC0-1.0
+
+module x;
+
+   typedef struct {
+      int b [2];
+   } notpacked_t;
+
+   notpacked_t n;
+
+   initial begin
+      n.b[0] = 1;
+      if (n.b[0] != 1) $stop;
+      $write("*-* All Finished *-*\n");
+      $finish;
+   end
+endmodule