add package verilator (#7332)

* add verilator package

* try to add environment variable and include folder

* manually install existing scripts and patch out spack's CXX wrapper

* added some comments

* make flake8 happy

var/spack/repos/builtin/packages/verilator/package.py

@@ -0,0 +1,80 @@
+##############################################################################
+# Copyright (c) 2013-2017, Lawrence Livermore National Security, LLC.
+# Produced at the Lawrence Livermore National Laboratory.
+#
+# This file is part of Spack.
+# Created by Todd Gamblin, tgamblin@llnl.gov, All rights reserved.
+# LLNL-CODE-647188
+#
+# For details, see https://github.com/spack/spack
+# Please also see the NOTICE and LICENSE files for our notice and the LGPL.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License (as
+# published by the Free Software Foundation) version 2.1, February 1999.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the IMPLIED WARRANTY OF
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the terms and
+# conditions of the GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+##############################################################################
+from spack import *
+
+
+class Verilator(AutotoolsPackage):
+    """Verilator is the fastest free Verilog HDL simulator.
+
+    It compiles synthesizable Verilog (not test-bench code!), plus some PSL,
+    SystemVerilog and Synthesis assertions into C++ or SystemC code. It is
+    designed for large projects where fast simulation performance is of primary
+    concern, and is especially well suited to generate executable models of
+    CPUs for embedded software design teams.
+
+    Please do not download this program if you are expecting a full featured
+    replacement for NC-Verilog, VCS or another commercial Verilog simulator
+    or Verilog compiler for a little project! (Try Icarus instead.) However, if
+    you are looking for a path to migrate synthesizable Verilog to C++ or
+    SystemC, and writing just a touch of C code and Makefiles doesn't scare you
+    off, this is the free Verilog compiler for you.
+
+    Verilator supports the synthesis subset of Verilog, plus initial
+    statements, proper blocking/non-blocking assignments, functions, tasks,
+    multi-dimensional arrays, and signed numbers. It also supports very simple
+    forms of SystemVerilog assertions and coverage analysis. Verilator supports
+    the more important Verilog 2005 constructs, and some SystemVerilog
+    features, with additional constructs being added as users request them.
+
+    Verilator has been used to simulate many very large multi-million gate
+    designs with thousands of modules."""
+
+    homepage = "https://www.veripool.org/projects/verilator"
+    url      = "https://www.veripool.org/ftp/verilator-3.920.tgz"
+
+    version('3.920', '71de7b9ddb27a72e96ed2a04e5ccf933')
+
+    depends_on('bison')
+    depends_on('flex')
+    depends_on('perl')
+
+    def setup_environment(self, spack_env, run_env):
+        run_env.prepend_path('VERILATOR_ROOT', self.prefix)
+
+    # verilator requires access to its shipped scripts (bin) and include
+    # but the standard make doesn't put it in the correct places
+    @run_before('install')
+    def install_include(self):
+        install_tree('include', prefix.include)
+        install_tree('bin', prefix.bin)
+
+    # we need to fix the CXX and LINK paths, as they point to the spack
+    # wrapper scripts which aren't usable without spack
+    @run_after('install')
+    def patch_CXX(self):
+        filter_file(r'^CXX\s*=.*', 'CXX = {0}'.format(self.compiler.cxx),
+                    join_path(self.prefix.include, 'verilated.mk'))
+        filter_file(r'^LINK\s*=.*', 'LINK = {0}'.format(self.compiler.cxx),
+                    join_path(self.prefix.include, 'verilated.mk'))