pw_build_info/py/build_id_test.py

# Copyright 2021 The Pigweed Authors
#
# 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
#
#     https://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.
"""Tests for pw_build_info's GNU build ID support."""

import subprocess
import tempfile
import unittest
from pathlib import Path

from pw_build_info import build_id

# Since build_id.cc depends on pw_preprocessor, we have to use the in-tree path.
_MODULE_DIR = Path(__file__).parent.parent.resolve()
_MODULE_PY_DIR = Path(__file__).parent.resolve()

_SHA1_BUILD_ID_LENGTH = 20


class TestGnuBuildId(unittest.TestCase):
    """Unit tests for GNU build ID parsing."""
    def test_build_id_correctness(self):
        """Tests to ensure GNU build IDs are read/written correctly."""
        with tempfile.TemporaryDirectory() as exe_dir:
            exe_file = Path(exe_dir) / 'print_build_id.elf'

            # Compiles a binary that prints the embedded GNU build id.
            cmd = [
                'clang++',
                'build_id.cc',
                _MODULE_PY_DIR / 'print_build_id.cc',
                '-Ipublic',
                '-I../pw_polyfill/public',
                '-I../pw_preprocessor/public',
                '-I../pw_span/public',
                '-std=c++17',
                '-fuse-ld=lld',
                '-Wl,-Tadd_build_id_to_default_linker_script.ld',
                '-Wl,--build-id=sha1',
                '-o',
                exe_file,
            ]

            process = subprocess.run(cmd,
                                     stdout=subprocess.PIPE,
                                     stderr=subprocess.STDOUT,
                                     cwd=_MODULE_DIR)
            self.assertEqual(process.returncode, 0,
                             process.stdout.decode(errors='replace'))

            # Run the compiled binary so the printed build ID can be read.
            process = subprocess.run([exe_file],
                                     stdout=subprocess.PIPE,
                                     stderr=subprocess.STDOUT,
                                     cwd=_MODULE_DIR)
            self.assertEqual(process.returncode, 0)

            with open(exe_file, 'rb') as elf:
                expected = build_id.read_build_id_from_section(elf)
                self.assertEqual(len(expected), _SHA1_BUILD_ID_LENGTH)
                self.assertEqual(process.stdout.decode().rstrip(),
                                 expected.hex())

                # Test method that parses using symbol information.
                expected = build_id.read_build_id_from_symbol(elf)
                self.assertEqual(len(expected), _SHA1_BUILD_ID_LENGTH)
                self.assertEqual(process.stdout.decode().rstrip(),
                                 expected.hex())

                # Test the user-facing method.
                expected = build_id.read_build_id(elf)
                self.assertEqual(len(expected), _SHA1_BUILD_ID_LENGTH)
                self.assertEqual(process.stdout.decode().rstrip(),
                                 expected.hex())


if __name__ == '__main__':
    unittest.main()