xref: /aosp_15_r20/build/soong/python/scripts/precompile_python.py (revision 333d2b3687b3a337dbcca9d65000bca186795e39) 
1#!/usr/bin/env python3
2# Copyright 2023 Google Inc. All rights reserved.
3#
4# Licensed under the Apache License, Version 2.0 (the "License");
5# you may not use this file except in compliance with the License.
6# You may obtain a copy of the License at
7#
8#     http://www.apache.org/licenses/LICENSE-2.0
9#
10# Unless required by applicable law or agreed to in writing, software
11# distributed under the License is distributed on an "AS IS" BASIS,
12# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13# See the License for the specific language governing permissions and
14# limitations under the License.
15
16from __future__ import print_function
17import argparse
18import py_compile
19import os
20import sys
21import shutil
22import tempfile
23import zipfile
24
25# This file needs to support both python 2 and 3.
26
27
28def process_one_file(name, infile, outzip):
29    # Create a ZipInfo instance with a fixed date to ensure a deterministic output.
30    # Date was chosen to be the same as
31    # https://cs.android.com/android/platform/superproject/main/+/main:build/soong/jar/jar.go;l=36;drc=2863e4535eb65e15f955dc8ed48fa99b1d2a1db5
32    info = zipfile.ZipInfo(filename=name, date_time=(2008, 1, 1, 0, 0, 0))
33    info.compress_type = zipfile.ZIP_DEFLATED
34
35    if not info.filename.endswith('.py'):
36        outzip.writestr(info, infile.read())
37        return
38
39    # Unfortunately py_compile requires the input/output files to be written
40    # out to disk.
41    with tempfile.NamedTemporaryFile(prefix="Soong_precompile_", delete=False) as tmp:
42        shutil.copyfileobj(infile, tmp)
43        in_name = tmp.name
44    with tempfile.NamedTemporaryFile(prefix="Soong_precompile_", delete=False) as tmp:
45        out_name = tmp.name
46    try:
47        # Ensure a deterministic .pyc output by using the hash rather than the timestamp.
48        # Only works on Python 3.7+
49        # See https://docs.python.org/3/library/py_compile.html#py_compile.PycInvalidationMode
50        if sys.version_info >= (3, 7):
51            py_compile.compile(in_name, out_name, info.filename, doraise=True, invalidation_mode=py_compile.PycInvalidationMode.CHECKED_HASH)
52        else:
53            py_compile.compile(in_name, out_name, info.filename, doraise=True)
54        with open(out_name, 'rb') as f:
55            info.filename = info.filename + 'c'
56            outzip.writestr(info, f.read())
57    finally:
58        os.remove(in_name)
59        os.remove(out_name)
60
61
62def main():
63    parser = argparse.ArgumentParser()
64    parser.add_argument('src_zip')
65    parser.add_argument('dst_zip')
66    args = parser.parse_args()
67
68    errors = []
69    with open(args.dst_zip, 'wb') as outf, open(args.src_zip, 'rb') as inf:
70        with zipfile.ZipFile(outf, mode='w') as outzip, zipfile.ZipFile(inf, mode='r') as inzip:
71            for name in inzip.namelist():
72                with inzip.open(name, mode='r') as inzipf:
73                    try:
74                        process_one_file(name, inzipf, outzip)
75                    except py_compile.PyCompileError as e:
76                        errors.append(e)
77
78    if errors:
79        for i, error in enumerate(errors):
80            # Print an empty line in between each error
81            if i > 0:
82                print(file=sys.stderr)
83            print(str(error).strip(), file=sys.stderr)
84        sys.exit(1)
85
86
87if __name__ == "__main__":
88    main()
89