build/rust/run_bindgen.py

#!/usr/bin/env python3

# Copyright 2022 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import argparse
import os
import subprocess
import sys

# Set up path to be able to import action_helpers.
sys.path.append(
    os.path.join(os.path.dirname(os.path.abspath(__file__)), os.pardir,
                 os.pardir, 'build'))
import action_helpers

from filter_clang_args import filter_clang_args


def atomic_copy(in_path, out_path):
  with open(in_path, 'rb') as input:
    with action_helpers.atomic_output(out_path) as output:
      content = input.read()
      output.write(content)


def copy_to_prefixed_filename(path, filename, prefix):
  atomic_copy(os.path.join(path, filename),
              os.path.join(path, prefix + "_" + filename))


def main():
  parser = argparse.ArgumentParser("run_bindgen.py")
  parser.add_argument("--exe", help="Path to bindgen", required=True),
  parser.add_argument("--header",
                      help="C header file to generate bindings for",
                      required=True)
  parser.add_argument("--depfile",
                      help="depfile to output with header dependencies")
  parser.add_argument("--output", help="output .rs bindings", required=True)
  parser.add_argument("--ld-library-path",
                      help="LD_LIBRARY_PATH (or DYLD_LIBRARY_PATH on Mac) to "
                      "set")
  parser.add_argument("-I", "--include", help="include path", action="append")
  parser.add_argument("--bindgen-flags",
                      help="flags to pass to bindgen",
                      nargs="*")
  parser.add_argument(
      "clangargs",
      metavar="CLANGARGS",
      help="arguments to pass to libclang (see "
      "https://docs.rs/bindgen/latest/bindgen/struct.Builder.html#method.clang_args)",
      nargs="*")
  args = parser.parse_args()

  # Args passed to the actual bindgen cli
  genargs = []
  genargs.append('--no-layout-tests')
  if args.bindgen_flags is not None:
    for flag in args.bindgen_flags:
      genargs.append("--" + flag)

  # TODO(danakj): We need to point bindgen to
  # //third_party/rust-toolchain/bin/rustfmt.
  genargs.append('--no-rustfmt-bindings')
  genargs += ['--rust-target', 'nightly']

  if args.depfile:
    genargs.append('--depfile')
    genargs.append(args.depfile)
  genargs.append('--output')
  genargs.append(args.output)
  genargs.append(args.header)
  genargs.append('--')
  genargs.extend(filter_clang_args(args.clangargs))
  env = os.environ
  if args.ld_library_path:
    if sys.platform == 'darwin':
      env["DYLD_LIBRARY_PATH"] = args.ld_library_path
    else:
      env["LD_LIBRARY_PATH"] = args.ld_library_path
  returncode = subprocess.run([args.exe, *genargs], env=env).returncode
  if returncode != 0:
    # Make sure we don't emit anything if bindgen failed.
    try:
      os.remove(args.output)
    except FileNotFoundError:
      pass
    try:
      os.remove(args.depfile)
    except FileNotFoundError:
      pass
  return returncode


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