veclibfort: add new package (#2080)

* veclibfort: add new package

* veclibfort: add a small test

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

+##############################################################################
+# Copyright (c) 2013-2016, 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/llnl/spack
+# Please also see the LICENSE file 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 *
+import sys
+
+
+class Veclibfort(Package):
+    """Lightweight but flexible shim designed to rectify the incompatibilities
+    between the Accelerate/vecLib BLAS and LAPACK libraries shipped with macOS
+    and FORTRAN code compiled with modern compilers such as GNU Fortran."""
+
+    homepage = "https://github.com/mcg1969/vecLibFort"
+    url      = "https://github.com/mcg1969/vecLibFort/archive/0.4.2.tar.gz"
+
+    version('0.4.2', '83395ffcbe8a2122c3f726a5c3a7cf93')
+    version('develop', git='https://github.com/mcg1969/vecLibFort.git')
+
+    variant('shared', default=True,
+            description="Build shared libraries as well as static libs.")
+
+    # virtual dependency
+    provides('blas')
+    provides('lapack')
+
+    @property
+    def blas_libs(self):
+        shared = True if '+shared' in self.spec else False
+        return find_libraries(
+            ['libvecLibFort'], root=self.prefix, shared=shared, recurse=True
+        )
+
+    @property
+    def lapack_libs(self):
+        return self.blas_libs
+
+    def install(self, spec, prefix):
+        if sys.platform != 'darwin':
+            raise InstallError('vecLibFort can be installed on macOS only')
+
+        make('all')
+        make('PREFIX=%s' % prefix, 'install')
+
+        # test
+        fc = which('fc')
+        flags = ['-o', 'tester', '-O', 'tester.f90']
+        flags.extend(self.lapack_libs.ld_flags.split())
+        fc(*flags)
+        Executable('./tester')()