rs_bindings_from_cc/rs_bindings_from_cc.cc

// Part of the Crubit project, under the Apache License v2.0 with LLVM
// Exceptions. See /LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

// Parses C++ headers and generates:
// * a Rust source file with bindings for the C++ API
// * a C++ source file with the implementation of the bindings

#include <memory>
#include <string>
#include <vector>

#include "base/init_google.h"
#include "base/logging.h"
#include "devtools/cymbal/common/clang_tool.h"
#include "rs_bindings_from_cc/frontend_action.h"
#include "rs_bindings_from_cc/ir.h"
#include "rs_bindings_from_cc/ir_from_cc.h"
#include "rs_bindings_from_cc/src_code_gen.h"
#include "file/base/filesystem.h"
#include "file/base/helpers.h"
#include "file/base/options.h"
#include "third_party/absl/container/flat_hash_map.h"
#include "third_party/absl/flags/flag.h"
#include "third_party/absl/strings/string_view.h"
#include "third_party/absl/strings/substitute.h"
#include "third_party/llvm/llvm-project/clang/include/clang/Frontend/FrontendAction.h"
#include "util/task/status.h"

ABSL_FLAG(std::string, rs_out, "",
          "output path for the Rust source file with bindings");
ABSL_FLAG(std::string, cc_out, "",
          "output path for the C++ source file with bindings implementation");
ABSL_FLAG(std::string, ir_out, "",
          "(optional) output path for the JSON IR. If not present, the JSON IR "
          "will not be dumped.");
ABSL_FLAG(std::vector<std::string>, public_headers, std::vector<std::string>(),
          "public headers of the cc_library this tool should generate bindings "
          "for, in a format suitable for usage in google3-relative quote "
          "include (#include \"\").");

int main(int argc, char* argv[]) {
  InitGoogle(argv[0], &argc, &argv, true);

  auto rs_out = absl::GetFlag(FLAGS_rs_out);
  QCHECK(!rs_out.empty()) << "please specify --rs_out";
  auto cc_out = absl::GetFlag(FLAGS_cc_out);
  QCHECK(!cc_out.empty()) << "please specify --cc_out";
  auto public_headers = absl::GetFlag(FLAGS_public_headers);
  QCHECK(!public_headers.empty())
      << "please specify at least one header in --public_headers";

  auto ir_out = absl::GetFlag(FLAGS_ir_out);  // Optional.

  if (absl::StatusOr<rs_bindings_from_cc::IR> ir =
          rs_bindings_from_cc::IrFromCc(
              {},
              std::vector<absl::string_view>(public_headers.begin(),
                                             public_headers.end()),

              std::vector<absl::string_view>(argv, argv + argc));
      ir.ok()) {
    if (!ir_out.empty()) {
      CHECK_OK(file::SetContents(ir_out, ir->ToJson().dump(/*indent=*/2),
                                 file::Defaults()));
    }
    rs_bindings_from_cc::Bindings bindings =
        rs_bindings_from_cc::GenerateBindings(*ir);
    CHECK_OK(file::SetContents(rs_out, bindings.rs_api, file::Defaults()));
    CHECK_OK(file::SetContents(cc_out, bindings.rs_api_impl, file::Defaults()));
    return 0;
  }

  file::Delete(rs_out, file::Defaults()).IgnoreError();
  file::Delete(cc_out, file::Defaults()).IgnoreError();
  if (!ir_out.empty()) {
    file::Delete(ir_out, file::Defaults()).IgnoreError();
  }
  return 1;
}