tools/lint_gn_rules_present.py

#!/usr/bin/env python3
# Copyright 2021 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""Checks that all source files are present in exactly 1 gn target"""

import sys
import os
# Ensure that this file can import from cobalt root even if run as a script.
sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))

import subprocess
import json
from tools import get_files

# Find the root directory of the cobalt core repository (One directory up from the tools/ directory)
cobalt_root = os.path.abspath(
    os.path.join(os.path.join(os.path.dirname(__file__), '..')))

ALLOW_ABSENCE = [
    # TODO(fxbug.dev/93229): Remove these once StatusOr move is done.
    'src/lib/statusor/statusor.h',  # Symlink to file in src/public/lib/statusor/
    'src/lib/statusor/status_macros.h',  # Symlink to file in src/public/lib/statusor/
    'src/lib/statusor/statusor_internals.h',  # Symlink to file in src/public/lib/statusor/
]

def main():
  out_path = os.path.join(cobalt_root, 'out')
  p = subprocess.Popen(
      ['gn', 'desc', out_path, '//*', 'sources', '--format=json'],
      stdout=subprocess.PIPE)
  out, err = p.communicate()

  if p.returncode != 0:
    print('Received non-zero return code (%s)' % p.returncode)
    print(out.decode())
    return 1

  data = json.loads(out)

  present_files = [
      os.path.relpath(f, cobalt_root) for f in get_files.files_to_lint(
          ('.h', '.cc'), only_directories=['src', 'keys'], all_files=True)
  ]

  seen_sources = set()
  errors = 0
  for target, attributes in data.items():
    if 'sources' not in attributes.keys():
      continue
    for source in attributes['sources']:
      if source.startswith('//out') or source.startswith(
          '//build') or source.startswith('//third_party'):
        # Auto-generated or added by //build rules. Duplicates are allowed.
        continue
      if source in seen_sources:
        print(
            f'Duplicate source detected {source} present in multiple GN targets {target}'
        )
        errors += 1
      seen_sources.add(source)

  for needed_file in present_files:
    if f'//{needed_file}' not in seen_sources and needed_file not in ALLOW_ABSENCE:
      print(
          f"Saw source file {needed_file} that wasn't present in any gn targets"
      )
      errors += 1

  return errors


if __name__ == '__main__':
  exit(main())