Fix $ in filenames (#2768).

src/V3Options.cpp

@@ -18,6 +18,7 @@
 #include "verilatedos.h"
 
 #include "V3Global.h"
+#include "V3Ast.h"
 #include "V3String.h"
 #include "V3Os.h"
 #include "V3Options.h"
@@ -864,10 +865,10 @@ void V3Options::parseOpts(FileLine* fl, int argc, char** argv) {
     }
 
     // Default prefix to the filename
-    if (prefix() == "" && topModule() != "") m_prefix = string("V") + topModule();
+    if (prefix() == "" && topModule() != "")
-    if (prefix() == "" && vFilesList.size() >= 1) {
+        m_prefix = string("V") + AstNode::encodeName(topModule());
-        m_prefix = string("V") + V3Os::filenameNonExt(*(vFilesList.begin()));
+    if (prefix() == "" && vFilesList.size() >= 1)
-    }
+        m_prefix = string("V") + AstNode::encodeName(V3Os::filenameNonExt(*(vFilesList.begin())));
     if (modPrefix() == "") m_modPrefix = prefix();
 
     // Find files in makedir

test_regress/t/t_mod_dollar$.pl

@@ -0,0 +1,25 @@
+#!/usr/bin/env perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2019 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+scenarios(vlt => 1);
+
+# This doesn't use the general compile rule as we want to make sure we form
+# prefix properly using post-escaped identifiers
+run(cmd => ["../bin/verilator",
+            "--cc",
+            "--Mdir obj_vlt/t_mod_dollar",
+            "--exe --build --main",
+            't/t_mod_dollar$.v',
+    ],
+    verilator_run => 1,
+    );
+
+ok(1);
+1;

test_regress/t/t_mod_dollar$.v

@@ -0,0 +1,12 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2020 by engr248.
+// SPDX-License-Identifier: CC0-1.0
+
+module \foo$bar (/*AUTOARG*/);
+   initial begin
+      $write("*-* All Finished *-*\n");
+      $finish;
+   end
+endmodule