Add manifest_check tool

Add a tool that can check that the <uses-library> tags in an
AndroidManifest.xml file match a list provided by the build.

Bug: 132357300
Test: manifest_check_test
Change-Id: If15abf792282bef677469595e80f19923b87ab62
diff --git a/scripts/manifest.py b/scripts/manifest.py
new file mode 100755
index 0000000..4c75f8b
--- /dev/null
+++ b/scripts/manifest.py
@@ -0,0 +1,117 @@
+#!/usr/bin/env python
+#
+# Copyright (C) 2018 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+"""A tool for inserting values from the build system into a manifest."""
+
+from __future__ import print_function
+from xml.dom import minidom
+
+
+android_ns = 'http://schemas.android.com/apk/res/android'
+
+
+def get_children_with_tag(parent, tag_name):
+  children = []
+  for child in  parent.childNodes:
+    if child.nodeType == minidom.Node.ELEMENT_NODE and \
+       child.tagName == tag_name:
+      children.append(child)
+  return children
+
+
+def find_child_with_attribute(element, tag_name, namespace_uri,
+                              attr_name, value):
+  for child in get_children_with_tag(element, tag_name):
+    attr = child.getAttributeNodeNS(namespace_uri, attr_name)
+    if attr is not None and attr.value == value:
+      return child
+  return None
+
+
+def parse_manifest(doc):
+  """Get the manifest element."""
+
+  manifest = doc.documentElement
+  if manifest.tagName != 'manifest':
+    raise RuntimeError('expected manifest tag at root')
+  return manifest
+
+
+def ensure_manifest_android_ns(doc):
+  """Make sure the manifest tag defines the android namespace."""
+
+  manifest = parse_manifest(doc)
+
+  ns = manifest.getAttributeNodeNS(minidom.XMLNS_NAMESPACE, 'android')
+  if ns is None:
+    attr = doc.createAttributeNS(minidom.XMLNS_NAMESPACE, 'xmlns:android')
+    attr.value = android_ns
+    manifest.setAttributeNode(attr)
+  elif ns.value != android_ns:
+    raise RuntimeError('manifest tag has incorrect android namespace ' +
+                       ns.value)
+
+
+def as_int(s):
+  try:
+    i = int(s)
+  except ValueError:
+    return s, False
+  return i, True
+
+
+def compare_version_gt(a, b):
+  """Compare two SDK versions.
+
+  Compares a and b, treating codenames like 'Q' as higher
+  than numerical versions like '28'.
+
+  Returns True if a > b
+
+  Args:
+    a: value to compare
+    b: value to compare
+  Returns:
+    True if a is a higher version than b
+  """
+
+  a, a_is_int = as_int(a.upper())
+  b, b_is_int = as_int(b.upper())
+
+  if a_is_int == b_is_int:
+    # Both are codenames or both are versions, compare directly
+    return a > b
+  else:
+    # One is a codename, the other is not.  Return true if
+    # b is an integer version
+    return b_is_int
+
+
+def get_indent(element, default_level):
+  indent = ''
+  if element is not None and element.nodeType == minidom.Node.TEXT_NODE:
+    text = element.nodeValue
+    indent = text[:len(text)-len(text.lstrip())]
+  if not indent or indent == '\n':
+    # 1 indent = 4 space
+    indent = '\n' + (' ' * default_level * 4)
+  return indent
+
+
+def write_xml(f, doc):
+  f.write('<?xml version="1.0" encoding="utf-8"?>\n')
+  for node in doc.childNodes:
+    f.write(node.toxml(encoding='utf-8') + '\n')