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_check.py b/scripts/manifest_check.py
new file mode 100755
index 0000000..9122da1
--- /dev/null
+++ b/scripts/manifest_check.py
@@ -0,0 +1,215 @@
+#!/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 checking that a manifest agrees with the build system."""
+
+from __future__ import print_function
+
+import argparse
+import sys
+from xml.dom import minidom
+
+
+from manifest import android_ns
+from manifest import get_children_with_tag
+from manifest import parse_manifest
+from manifest import write_xml
+
+
+class ManifestMismatchError(Exception):
+  pass
+
+
+def parse_args():
+  """Parse commandline arguments."""
+
+  parser = argparse.ArgumentParser()
+  parser.add_argument('--uses-library', dest='uses_libraries',
+                      action='append',
+                      help='specify uses-library entries known to the build system')
+  parser.add_argument('--optional-uses-library',
+                      dest='optional_uses_libraries',
+                      action='append',
+                      help='specify uses-library entries known to the build system with required:false')
+  parser.add_argument('--enforce-uses-libraries',
+                      dest='enforce_uses_libraries',
+                      action='store_true',
+                      help='check the uses-library entries known to the build system against the manifest')
+  parser.add_argument('--extract-target-sdk-version',
+                      dest='extract_target_sdk_version',
+                      action='store_true',
+                      help='print the targetSdkVersion from the manifest')
+  parser.add_argument('--output', '-o', dest='output', help='output AndroidManifest.xml file')
+  parser.add_argument('input', help='input AndroidManifest.xml file')
+  return parser.parse_args()
+
+
+def enforce_uses_libraries(doc, uses_libraries, optional_uses_libraries):
+  """Verify that the <uses-library> tags in the manifest match those provided by the build system.
+
+  Args:
+    doc: The XML document.
+    uses_libraries: The names of <uses-library> tags known to the build system
+    optional_uses_libraries: The names of <uses-library> tags with required:fals
+      known to the build system
+  Raises:
+    RuntimeError: Invalid manifest
+    ManifestMismatchError: Manifest does not match
+  """
+
+  manifest = parse_manifest(doc)
+  elems = get_children_with_tag(manifest, 'application')
+  application = elems[0] if len(elems) == 1 else None
+  if len(elems) > 1:
+    raise RuntimeError('found multiple <application> tags')
+  elif not elems:
+    if uses_libraries or optional_uses_libraries:
+      raise ManifestMismatchError('no <application> tag found')
+    return
+
+  verify_uses_library(application, uses_libraries, optional_uses_libraries)
+
+
+def verify_uses_library(application, uses_libraries, optional_uses_libraries):
+  """Verify that the uses-library values known to the build system match the manifest.
+
+  Args:
+    application: the <application> tag in the manifest.
+    uses_libraries: the names of expected <uses-library> tags.
+    optional_uses_libraries: the names of expected <uses-library> tags with required="false".
+  Raises:
+    ManifestMismatchError: Manifest does not match
+  """
+
+  if uses_libraries is None:
+    uses_libraries = []
+
+  if optional_uses_libraries is None:
+    optional_uses_libraries = []
+
+  manifest_uses_libraries, manifest_optional_uses_libraries = parse_uses_library(application)
+
+  err = []
+  if manifest_uses_libraries != uses_libraries:
+    err.append('Expected required <uses-library> tags "%s", got "%s"' %
+               (', '.join(uses_libraries), ', '.join(manifest_uses_libraries)))
+
+  if manifest_optional_uses_libraries != optional_uses_libraries:
+    err.append('Expected optional <uses-library> tags "%s", got "%s"' %
+               (', '.join(optional_uses_libraries), ', '.join(manifest_optional_uses_libraries)))
+
+  if err:
+    raise ManifestMismatchError('\n'.join(err))
+
+
+def parse_uses_library(application):
+  """Extract uses-library tags from the manifest.
+
+  Args:
+    application: the <application> tag in the manifest.
+  """
+
+  libs = get_children_with_tag(application, 'uses-library')
+
+  uses_libraries = [uses_library_name(x) for x in libs if uses_library_required(x)]
+  optional_uses_libraries = [uses_library_name(x) for x in libs if not uses_library_required(x)]
+
+  return first_unique_elements(uses_libraries), first_unique_elements(optional_uses_libraries)
+
+
+def first_unique_elements(l):
+  result = []
+  [result.append(x) for x in l if x not in result]
+  return result
+
+
+def uses_library_name(lib):
+  """Extract the name attribute of a uses-library tag.
+
+  Args:
+    lib: a <uses-library> tag.
+  """
+  name = lib.getAttributeNodeNS(android_ns, 'name')
+  return name.value if name is not None else ""
+
+
+def uses_library_required(lib):
+  """Extract the required attribute of a uses-library tag.
+
+  Args:
+    lib: a <uses-library> tag.
+  """
+  required = lib.getAttributeNodeNS(android_ns, 'required')
+  return (required.value == 'true') if required is not None else True
+
+
+def extract_target_sdk_version(doc):
+  """Returns the targetSdkVersion from the manifest.
+
+  Args:
+    doc: The XML document.
+  Raises:
+    RuntimeError: invalid manifest
+  """
+
+  manifest = parse_manifest(doc)
+
+  # Get or insert the uses-sdk element
+  uses_sdk = get_children_with_tag(manifest, 'uses-sdk')
+  if len(uses_sdk) > 1:
+    raise RuntimeError('found multiple uses-sdk elements')
+  elif len(uses_sdk) == 0:
+    raise RuntimeError('missing uses-sdk element')
+
+  uses_sdk = uses_sdk[0]
+
+  min_attr = uses_sdk.getAttributeNodeNS(android_ns, 'minSdkVersion')
+  if min_attr is None:
+    raise RuntimeError('minSdkVersion is not specified')
+
+  target_attr = uses_sdk.getAttributeNodeNS(android_ns, 'targetSdkVersion')
+  if target_attr is None:
+    target_attr = min_attr
+
+  return target_attr.value
+
+
+def main():
+  """Program entry point."""
+  try:
+    args = parse_args()
+
+    doc = minidom.parse(args.input)
+
+    if args.enforce_uses_libraries:
+      enforce_uses_libraries(doc,
+                             args.uses_libraries,
+                             args.optional_uses_libraries)
+
+    if args.extract_target_sdk_version:
+      print(extract_target_sdk_version(doc))
+
+    if args.output:
+      with open(args.output, 'wb') as f:
+        write_xml(f, doc)
+
+  # pylint: disable=broad-except
+  except Exception as err:
+    print('error: ' + str(err), file=sys.stderr)
+    sys.exit(-1)
+
+if __name__ == '__main__':
+  main()