Merge "Add lint database filtering tool" into sc-dev

1 files changed, 136 insertions, 0 deletions

diff --git a/api/api_versions_trimmer.py b/api/api_versions_trimmer.py
new file mode 100755
index 000000000000..9afd95a3003a
--- /dev/null
+++ b/api/api_versions_trimmer.py
@@ -0,0 +1,136 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2021 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.
+
+"""Script to remove mainline APIs from the api-versions.xml."""
+
+import argparse
+import re
+import xml.etree.ElementTree as ET
+import zipfile
+
+
+def read_classes(stubs):
+  """Read classes from the stubs file.
+
+  Args:
+    stubs: argument can be a path to a file (a string), a file-like object or a
+    path-like object
+
+  Returns:
+    a set of the classes found in the file (set of strings)
+  """
+  classes = set()
+  with zipfile.ZipFile(stubs) as z:
+    for info in z.infolist():
+      if (not info.is_dir()
+          and info.filename.endswith(".class")
+          and not info.filename.startswith("META-INF")):
+        # drop ".class" extension
+        classes.add(info.filename[:-6])
+  return classes
+
+
+def filter_method_tag(method, classes_to_remove):
+  """Updates the signature of this method by calling filter_method_signature.
+
+  Updates the method passed into this function.
+
+  Args:
+    method: xml element that represents a method
+    classes_to_remove: set of classes you to remove
+  """
+  filtered = filter_method_signature(method.get("name"), classes_to_remove)
+  method.set("name", filtered)
+
+
+def filter_method_signature(signature, classes_to_remove):
+  """Removes mentions of certain classes from this method signature.
+
+  Replaces any existing classes that need to be removed, with java/lang/Object
+
+  Args:
+    signature: string that is a java representation of a method signature
+    classes_to_remove: set of classes you to remove
+  """
+  regex = re.compile("L.*?;")
+  start = signature.find("(")
+  matches = set(regex.findall(signature[start:]))
+  for m in matches:
+    # m[1:-1] to drop the leading `L` and `;` ending
+    if m[1:-1] in classes_to_remove:
+      signature = signature.replace(m, "Ljava/lang/Object;")
+  return signature
+
+
+def filter_lint_database(database, classes_to_remove, output):
+  """Reads a lint database and writes a filtered version without some classes.
+
+  Reads database from api-versions.xml and removes any references to classes
+  in the second argument. Writes the result (another xml with the same format
+  of the database) to output.
+
+  Args:
+    database: path to xml with lint database to read
+    classes_to_remove: iterable (ideally a set or similar for quick
+    lookups) that enumerates the classes that should be removed
+    output: path to write the filtered database
+  """
+  xml = ET.parse(database)
+  root = xml.getroot()
+  for c in xml.findall("class"):
+    cname = c.get("name")
+    if cname in classes_to_remove:
+      root.remove(c)
+    else:
+      # find the <extends /> tag inside this class to see if the parent
+      # has been removed from the known classes (attribute called name)
+      super_classes = c.findall("extends")
+      for super_class in super_classes:
+        super_class_name = super_class.get("name")
+        if super_class_name in classes_to_remove:
+          super_class.set("name", "java/lang/Object")
+      interfaces = c.findall("implements")
+      for interface in interfaces:
+        interface_name = interface.get("name")
+        if interface_name in classes_to_remove:
+          c.remove(interface)
+      for method in c.findall("method"):
+        filter_method_tag(method, classes_to_remove)
+  xml.write(output)
+
+
+def main():
+  """Run the program."""
+  parser = argparse.ArgumentParser(
+      description=
+      ("Read a lint database (api-versions.xml) and many stubs jar files. "
+       "Produce another database file that doesn't include the classes present "
+       "in the stubs file(s)."))
+  parser.add_argument("output", help="Destination of the result (xml file).")
+  parser.add_argument(
+      "api_versions",
+      help="The lint database (api-versions.xml file) to read data from"
+  )
+  parser.add_argument("stubs", nargs="+", help="The stubs jar file(s)")
+  parsed = parser.parse_args()
+  classes = set()
+  for stub in parsed.stubs:
+    classes.update(read_classes(stub))
+  filter_lint_database(parsed.api_versions, classes, parsed.output)
+
+
+if __name__ == "__main__":
+  main()