recipes/clang_toolchain.resources/runtimes.py

# Copyright 2019 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.
"""Script to emit runtimes.json for Clang toolchain"""

import argparse
import collections
import json
import os
import re
import subprocess
import sys


def read_build_id(readelf, filename):
  p = subprocess.Popen([readelf, '-n', filename],
                       stdout=subprocess.PIPE,
                       env={'LC_ALL': 'C'})
  stdout, _ = p.communicate()
  if p.returncode != 0:
    raise Exception('failed to read notes')
  match = re.search(r'Build ID: ([a-zA-Z0-9_-]+)', stdout)
  if not match:
    raise Exception('build ID missing')
  return match.group(1)


def generate_entry(dirname, readelf, soname, filename):
  build_id = read_build_id(
      readelf, os.path.realpath(os.path.join(dirname, 'lib', filename)))
  return {
      'soname': soname,
      'dist': filename,
      'debug': 'debug/.build-id/%s/%s.debug' % (build_id[0:2], build_id[2:])
  }


Target = collections.namedtuple('Target', ['triple', 'aliases'])


class TargetAction(argparse.Action):

  def __call__(self, parser, namespace, values, option_string=None):
    targets = getattr(namespace, 'target')
    targets.append(Target(triple=values, aliases=[]))


class AliasAction(argparse.Action):

  def __call__(self, parser, namespace, values, option_string=None):
    targets = getattr(namespace, 'target')
    if not targets:
      raise argparse.ArgumentError(self, 'missing --target')
    targets[-1].aliases.append(values)


def main():
  parser = argparse.ArgumentParser(description=__doc__)
  parser.add_argument('--dir', default=os.getcwd(), help='Clang directory')
  parser.add_argument(
      '--readelf', required=True, help='path to readelf utility')
  parser.add_argument(
      '--resource-dir', required=True, help='Clang resource directory')
  parser.add_argument(
      '--manifest',
      action='store_const',
      const=True,
      default=False,
      help='Emit old manifest format instead of JSON')
  parser.add_argument(
      '--target',
      metavar='TRIPLE',
      default=[],
      action=TargetAction,
      help='--target=TRIPLE values to support')
  parser.add_argument(
      '--alias',
      metavar='TRIPLE',
      action=AliasAction,
      help='--target=TRIPLE alias, applies to preceding --target')
  args = parser.parse_args()

  runtimes = []
  for target in args.target:
    runtime_dir = '{resource_dir}/lib/{target}'.format(
        resource_dir=args.resource_dir, target=target.triple)
    cxx_lib_dir = '{target}/c++'.format(target=target.triple)
    manifest = {}
    for mode_ldflags in [[], ['-static-libstdc++']]:
      for mode_cflags, mode_multilib, mode_runtimes in [
          ([], '', []),
          (['-fsanitize=address'], 'asan/', ['libclang_rt.asan.so']),
          (['-fsanitize=undefined'], '', ['libclang_rt.ubsan_standalone.so']),
      ]:
        runtime = [
            generate_entry(args.dir, args.readelf, soname,
                           runtime_dir + '/' + soname)
            for soname in mode_runtimes
        ]
        for lib in runtime:
          manifest['lib/' + lib['soname']] = lib['dist']
        if not mode_ldflags:
          cxx_lib = [
              generate_entry(args.dir, args.readelf, soname,
                             cxx_lib_dir + '/' + mode_multilib + soname)
              for soname in ['libc++.so.2', 'libc++abi.so.1', 'libunwind.so.1']
          ]
          runtime.extend(cxx_lib)
          for lib in cxx_lib:
            manifest['lib/' + mode_multilib + lib['soname']] = lib['dist']

        runtimes.append({
            'target': [target.triple] + target.aliases,
            'cflags': mode_cflags,
            'ldflags': mode_ldflags,
            'runtime': runtime,
        })

  if args.manifest:
    sys.stdout.write(''.join(
        sorted('%s=%s\n' % x for x in manifest.iteritems())))
  else:
    json.dump(runtimes, sys.stdout, indent=2, sort_keys=True)

  return 0


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