1#!/usr/bin/env python3
2#
3# Copyright (C) 2019 The Android Open Source Project
4#
5# Licensed under the Apache License, Version 2.0 (the "License");
6# you may not use this file except in compliance with the License.
7# You may obtain a copy of the License at
8#
9#      http://www.apache.org/licenses/LICENSE-2.0
10#
11# Unless required by applicable law or agreed to in writing, software
12# distributed under the License is distributed on an "AS IS" BASIS,
13# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14# See the License for the specific language governing permissions and
15# limitations under the License.
16
17"""This module contains utilities to extract Android build system variables."""
18
19import os.path
20
21
22def find_android_build_top(path):
23    """This function finds ANDROID_BUILD_TOP by searching parent directories of
24    `path`."""
25    path = os.path.dirname(os.path.abspath(path))
26    prev = None
27    while prev != path:
28        if os.path.exists(os.path.join(path, '.repo', 'manifest.xml')):
29            return path
30        prev = path
31        path = os.path.dirname(path)
32    raise ValueError('failed to find ANDROID_BUILD_TOP')
33