Add gams recipe (#12700)

* Add gams recipe

* Break down lines to pass lint

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

@@ -0,0 +1,37 @@
+# Copyright 2013-2019 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+from spack import *
+import os
+
+
+class Gams(Package):
+    """The General Algebraic Modeling System is a high-level modeling system
+    for mathematical optimization. GAMS is designed for modeling and solving
+    linear, nonlinear, and mixed-integer optimization problems."""
+
+    homepage = "https://www.gams.com/"
+    version('27.2', '4f3f3484a4389661e0522a4cfe0289fd', expand=False)
+
+    def url_for_version(self, version):
+        return "file://{0}/linux_x64_64_sfx.exe".format(os.getcwd())
+
+    def setup_environment(self, spack_env, run_env):
+        run_env.prepend_path("PATH", join_path(self.prefix,
+                                               'gams{0}_linux_x64_64_sfx'
+                                               .format(self.version)))
+
+    def install(self, spec, prefix):
+        os.chmod(join_path(self.stage.source_path,
+                           "linux_x64_64_sfx.exe"), 0o755)
+        os.system("./linux_x64_64_sfx.exe")
+        install_tree(join_path(self.stage.source_path,
+                               'gams{0}_linux_x64_64_sfx'
+                               .format(self.version)),
+                     join_path(self.prefix, 'gams{0}_linux_x64_64_sfx'
+                               .format(self.version)))
+        install('{0}/gamslice.txt'.format(os.getcwd()),
+                join_path(self.prefix, 'gams{0}_linux_x64_64_sfx'
+                          .format(self.version), 'gamslice.txt'))