From af38e8d38731dc8bbd1e69afafefe636d6d3b451 Mon Sep 17 00:00:00 2001
From: Wilson Snyder <wsnyder@wsnyder.org>
Date: Tue, 14 Jan 2020 07:33:12 -0500
Subject: [PATCH] Improve error on > 127 char modnames. #2106.

---
 src/V3Options.cpp                  |  7 +++-
 test_regress/t/t_inst_long_bad.out |  6 +++
 test_regress/t/t_inst_long_bad.pl  | 60 ++++++++++++++++++++++++++++++
 3 files changed, 72 insertions(+), 1 deletion(-)
 create mode 100644 test_regress/t/t_inst_long_bad.out
 create mode 100755 test_regress/t/t_inst_long_bad.pl

diff --git a/src/V3Options.cpp b/src/V3Options.cpp
index 184d92c5b..455050a66 100644
--- a/src/V3Options.cpp
+++ b/src/V3Options.cpp
@@ -374,7 +374,12 @@ string V3Options::filePath(FileLine* fl, const string& modname, const string& la
 
 void V3Options::filePathLookedMsg(FileLine* fl, const string& modname) {
     static bool shown_notfound_msg = false;
-    if (!shown_notfound_msg) {
+    if (modname.find("__Vhsh") != string::npos) {
+        std::cerr << V3Error::warnMore() << "... Unsupported: Name is longer than 127 characters;"
+                  << " automatic file lookup not supported.\n";
+        std::cerr << V3Error::warnMore() << "... Suggest putting filename with this module/package"
+                  << " onto command line instead.\n";
+    } else if (!shown_notfound_msg) {
         shown_notfound_msg = true;
         if (m_impp->m_incDirUsers.empty()) {
             fl->v3error("This may be because there's no search path specified with -I<dir>."<<endl);
diff --git a/test_regress/t/t_inst_long_bad.out b/test_regress/t/t_inst_long_bad.out
new file mode 100644
index 000000000..24c5fdbae
--- /dev/null
+++ b/test_regress/t/t_inst_long_bad.out
@@ -0,0 +1,6 @@
+%Error: obj_vlt/t_inst_long_bad/t_inst_long.v:4: Cannot find file containing module: 'long_long_long_long_long_long_lo__Vhsh1JZCXQVBM1QiASYlLmgTuAXYyUr7VAbJYwVHfiAD'
+  long_long_long_long_long_long_long_long_long_long_long_long_long_long_long_long_long_long_long_long_long_long_long_long_long_long_long_long_long_long_long_long_long_long_long_long_long_long_long_long_ inst ();
+  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+        ... Unsupported: Name is longer than 127 characters; automatic file lookup not supported.
+        ... Suggest putting filename with this module/package onto command line instead.
+%Error: Exiting due to
diff --git a/test_regress/t/t_inst_long_bad.pl b/test_regress/t/t_inst_long_bad.pl
new file mode 100755
index 000000000..7bcd414ac
--- /dev/null
+++ b/test_regress/t/t_inst_long_bad.pl
@@ -0,0 +1,60 @@
+#!/usr/bin/perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+
+use IO::File;
+use strict;
+use vars qw($Self);
+
+scenarios(vlt => 1);
+
+my $length = 200;
+my $long = "long_" x (($length + 4) / 5);
+
+sub gen_top {
+    my $filename = shift;
+
+    my $fh = IO::File->new(">$filename")
+        or $Self->error("Can't write $filename");
+    $fh->print("// Generated by t_inst_long.pl\n");
+    $fh->print("module t;\n");
+    $fh->print("\n");
+    $fh->print("  ${long} inst ();\n");
+    $fh->print("\n");
+    $fh->print("endmodule\n");
+    $fh->close;
+}
+
+sub gen_sub {
+    my $filename = shift;
+
+    my $fh = IO::File->new(">$filename")
+        or $Self->error("Can't write $filename");
+    $fh->print("// Generated by t_inst_long.pl\n");
+    $fh->print("module ${long};\n");
+    $fh->print("\n");
+    $fh->print("  initial begin\n");
+    $fh->print("     \$write(\"*-* All Finished *-*\\n\");\n");
+    $fh->print("     \$finish;\n");
+    $fh->print("  end\n");
+    $fh->print("endmodule\n");
+    $fh->close;
+}
+
+top_filename("$Self->{obj_dir}/t_inst_long.v", $long);
+
+gen_top($Self->{top_filename});
+gen_sub("$Self->{obj_dir}/${long}.v");
+
+lint(
+    fails => 1,
+    expect_filename => $Self->{golden_filename},
+    );
+
+ok(1);
+1;