1 files changed, 84 insertions, 0 deletions
diff --git a/lib/ansible/vars/reserved.py b/lib/ansible/vars/reserved.py
new file mode 100644
index 0000000..2d1b4d5
--- /dev/null
+++ b/lib/ansible/vars/reserved.py
@@ -0,0 +1,84 @@
+# (c) 2017 Ansible By Red Hat
+#
+# This file is part of Ansible
+#
+# Ansible is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Ansible 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
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
+
+# Make coding more python3-ish
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+from ansible.playbook import Play
+from ansible.playbook.block import Block
+from ansible.playbook.role import Role
+from ansible.playbook.task import Task
+from ansible.utils.display import Display
+
+display = Display()
+
+
+def get_reserved_names(include_private=True):
+    ''' this function returns the list of reserved names associated with play objects'''
+
+    public = set()
+    private = set()
+    result = set()
+
+    # FIXME: find a way to 'not hardcode', possibly need role deps/includes
+    class_list = [Play, Role, Block, Task]
+
+    for aclass in class_list:
+        # build ordered list to loop over and dict with attributes
+        for name, attr in aclass.fattributes.items():
+            if attr.private:
+                private.add(name)
+            else:
+                public.add(name)
+
+    # local_action is implicit with action
+    if 'action' in public:
+        public.add('local_action')
+
+    # loop implies with_
+    # FIXME: remove after with_ is not only deprecated but removed
+    if 'loop' in private or 'loop' in public:
+        public.add('with_')
+
+    if include_private:
+        result = public.union(private)
+    else:
+        result = public
+
+    return result
+
+
+def warn_if_reserved(myvars, additional=None):
+    ''' this function warns if any variable passed conflicts with internally reserved names '''
+
+    if additional is None:
+        reserved = _RESERVED_NAMES
+    else:
+        reserved = _RESERVED_NAMES.union(additional)
+
+    varnames = set(myvars)
+    varnames.discard('vars')  # we add this one internally, so safe to ignore
+    for varname in varnames.intersection(reserved):
+        display.warning('Found variable using reserved name: %s' % varname)
+
+
+def is_reserved_name(name):
+    return name in _RESERVED_NAMES
+
+
+_RESERVED_NAMES = frozenset(get_reserved_names())