text: #!/usr/bin/env python
  # Copyright 2019 The Chromium Authors. All rights reserved.
  # Use of this source code is governed by a BSD-style license that can be
  # found in the LICENSE file.
  r"""Automatically fetch, build, and run clang-tidy from source.
  
  This script seeks to automate the steps detailed in docs/clang_tidy.md.
  
  Example: the following command disables clang-tidy's default checks (-*) and
  enables the clang static analyzer checks.
  
      tools/clang/scripts/clang_tidy_tool.py \\
         --checks='-*,clang-analyzer-*,-clang-analyzer-alpha*' \\
         --header-filter='.*' \\
         out/Release chrome
  
  The same, but checks the changes only.
  
      git diff -U5 | tools/clang/scripts/clang_tidy_tool.py \\
         --diff \\
         --checks='-*,clang-analyzer-*,-clang-analyzer-alpha*' \\
         --header-filter='.*' \\
         out/Release chrome
  """
  
  from __future__ import print_function
  
  import argparse
  import os
  import subprocess
  import sys
  import update
  
  import build_clang_tools_extra
  
  
  def GetBinaryPath(build_dir, binary):
    if sys.platform == 'win32':
      binary += '.exe'
    return os.path.join(build_dir, 'bin', binary)
  
  
  def BuildNinjaTarget(out_dir, ninja_target):
    args = ['autoninja', '-C', out_dir, ninja_target]
    subprocess.check_call(args, shell=sys.platform == 'win32')
  
  
  def GenerateCompDb(out_dir):
    gen_compdb_script = os.path.join(
        os.path.dirname(__file__), 'generate_compdb.py')
    comp_db_file_path = os.path.join(out_dir, 'compile_commands.json')
    args = [
        sys.executable,
        gen_compdb_script,
        '-p',
        out_dir,
        '-o',
        comp_db_file_path,
    ]
    subprocess.check_call(args)
  
    # The resulting CompDb file includes /showIncludes which causes clang-tidy to
    # output a lot of unnecessary text to the console.
    with open(comp_db_file_path, 'r') as comp_db_file:
      comp_db_data = comp_db_file.read();
  
    # The trailing space on /showIncludes helps keep single-spaced flags.
    comp_db_data = comp_db_data.replace('/showIncludes ', '')
  
    with open(comp_db_file_path, 'w') as comp_db_file:
      comp_db_file.write(comp_db_data)
  
  
  def RunClangTidy(checks, header_filter, auto_fix, clang_src_dir,
                   clang_build_dir, out_dir, ninja_target):
    """Invoke the |run-clang-tidy.py| script."""
    run_clang_tidy_script = os.path.join(
        clang_src_dir, 'clang-tools-extra', 'clang-tidy', 'tool',
        'run-clang-tidy.py')
  
    clang_tidy_binary = GetBinaryPath(clang_build_dir, 'clang-tidy')
    clang_apply_rep_binary = GetBinaryPath(clang_build_dir,
                                           'clang-apply-replacements')
  
    args = [
        sys.executable,
        run_clang_tidy_script,
        '-quiet',
        '-p',
        out_dir,
        '-clang-tidy-binary',
        clang_tidy_binary,
        '-clang-apply-replacements-binary',
        clang_apply_rep_binary,
    ]
  
    if checks:
      args.append('-checks={}'.format(checks))
  
    if header_filter:
      args.append('-header-filter={}'.format(header_filter))
  
    if auto_fix:
      args.append('-fix')
  
    args.append(ninja_target)
    subprocess.check_call(args)
  
  
  def RunClangTidyDiff(checks, header_filter, auto_fix, clang_src_dir,
                       clang_build_dir, out_dir):
    """Invoke the |clang-tidy-diff.py| script over the diff from stdin."""
    clang_tidy_diff_script = os.path.join(
        clang_src_dir, 'clang-tools-extra', 'clang-tidy', 'tool',
        'clang-tidy-diff.py')
  
    clang_tidy_binary = GetBinaryPath(clang_build_dir, 'clang-tidy')
  
    args = [
        clang_tidy_diff_script,
        '-quiet',
        '-p1',
        '-path',
        out_dir,
        '-clang-tidy-binary',
        clang_tidy_binary,
    ]
  
    if checks:
      args.append('-checks={}'.format(checks))
  
    if header_filter:
      args.append('-header-filter={}'.format(header_filter))
  
    if auto_fix:
      args.append('-fix')
  
    subprocess.check_call(args)
  
  
  def main():
    script_name = sys.argv[0]
  
    parser = argparse.ArgumentParser(
        formatter_class=argparse.RawDescriptionHelpFormatter, epilog=__doc__)
    parser.add_argument(
        '--fetch',
        nargs='?',
        const=update.CLANG_REVISION,
        help='Fetch and build clang sources')
    parser.add_argument(
        '--build',
        action='store_true',
        help='build clang sources to get clang-tidy')
    parser.add_argument(
        '--diff',
        action='store_true',
        default=False,
        help ='read diff from the stdin and check it')
    parser.add_argument('--clang-src-dir', type=str,
                        help='override llvm and clang checkout location')
    parser.add_argument('--clang-build-dir', type=str,
                        help='override clang build dir location')
    parser.add_argument('--checks', help='passed to clang-tidy')
    parser.add_argument('--header-filter', help='passed to clang-tidy')
    parser.add_argument(
        '--auto-fix',
        action='store_true',
        help='tell clang-tidy to auto-fix errors')
    parser.add_argument('OUT_DIR', help='where we are building Chrome')
    parser.add_argument('NINJA_TARGET', help='ninja target')
    args = parser.parse_args()
  
    steps = []
  
    # If the user hasn't provided a clang checkout and build dir, checkout and
    # build clang-tidy where update.py would.
    if not args.clang_src_dir:
      args.clang_src_dir = build_clang_tools_extra.GetCheckoutDir(args.OUT_DIR)
    if not args.clang_build_dir:
      args.clang_build_dir = build_clang_tools_extra.GetBuildDir(args.OUT_DIR)
    elif (args.clang_build_dir and not
          os.path.isfile(GetBinaryPath(args.clang_build_dir, 'clang-tidy'))):
      sys.exit('clang-tidy binary doesn\'t exist at ' +
               GetBinaryPath(args.clang_build_dir, 'clang-tidy'))
  
    if args.fetch:
      steps.append(('Fetching LLVM sources', lambda:
                    build_clang_tools_extra.FetchLLVM(args.clang_src_dir,
                                                      args.fetch)))
  
    if args.build:
      steps.append(('Building clang-tidy',
                    lambda: build_clang_tools_extra.BuildTargets(
                        args.clang_build_dir,
                        ['clang-tidy', 'clang-apply-replacements'])))
  
    steps += [
        ('Building ninja target: %s' % args.NINJA_TARGET,
        lambda: BuildNinjaTarget(args.OUT_DIR, args.NINJA_TARGET)),
        ('Generating compilation DB', lambda: GenerateCompDb(args.OUT_DIR))
      ]
    if args.diff:
      steps += [
          ('Running clang-tidy on diff',
           lambda: RunClangTidyDiff(args.checks, args.header_filter,
                                    args.auto_fix, args.clang_src_dir,
                                    args.clang_build_dir, args.OUT_DIR,
                                    args.NINJA_TARGET)),
      ]
    else:
      steps += [
          ('Running clang-tidy',
          lambda: RunClangTidy(args.checks, args.header_filter,
                               args.auto_fix, args.clang_src_dir,
                               args.clang_build_dir, args.OUT_DIR,
                               args.NINJA_TARGET)),
      ]
  
    # Run the steps in sequence.
    for i, (msg, step_func) in enumerate(steps):
      # Print progress message
      print('-- %s %s' % (script_name, '-' * (80 - len(script_name) - 4)))
      print('-- [%d/%d] %s' % (i + 1, len(steps), msg))
      print(80 * '-')
  
      step_func()
  
    return 0
  
  
  if __name__ == '__main__':
    sys.exit(main())
  