/*
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <folly/ExceptionString.h>

namespace folly {

/**
 * Debug string for an exception: include type and what(), if
 * defined.
 */
fbstring exceptionStr(const std::exception& e) {
#if FOLLY_HAS_RTTI
  fbstring rv(demangle(typeid(e)));
  rv += ": ";
#else
  fbstring rv("Exception (no RTTI available): ");
#endif
  rv += e.what();
  return rv;
}

fbstring exceptionStr(std::exception_ptr ep) {
  if (!kHasExceptions) {
    return "Exception (catch unavailable)";
  }
  return catch_exception(
      [&]() -> fbstring {
        return catch_exception<std::exception const&>(
            [&]() -> fbstring { std::rethrow_exception(ep); },
            [](auto&& e) { return exceptionStr(e); });
      },
      []() -> fbstring { return "<unknown exception>"; });
}

} // namespace folly

/*
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <folly/ExceptionString.h>

#include <utility>

namespace folly {

/**
 * Debug string for an exception: include type and what(), if
 * defined.
 */
fbstring exceptionStr(const std::exception& e) {
#if FOLLY_HAS_RTTI
  fbstring rv(demangle(typeid(e)));
  rv += ": ";
#else
  fbstring rv("Exception (no RTTI available): ");
#endif
  rv += e.what();
  return rv;
}

fbstring exceptionStr(std::exception_ptr ep) {
  if (!kHasExceptions) {
    return "Exception (catch unavailable)";
  }
  return catch_exception(
      [&]() -> fbstring {
        return catch_exception<std::exception const&>(
            [&]() -> fbstring { std::rethrow_exception(std::move(ep)); },
            [](auto&& e) { return exceptionStr(e); });
      },
      []() -> fbstring { return "<unknown exception>"; });
}

} // namespace folly

Move an exception_ptr in exceptionStr
Move an exception_ptr in exceptionStr

Summary: [Folly] Move an `exception_ptr` in `exceptionStr`, which should be ever-so-slightly cheaper than copying it since that may avoid atomic refcount operations. It's not much cheaper overall because the throw/catch machinery remains expensive.

Reviewed By: ot, luciang

Differential Revision: D22529858

fbshipit-source-id: 7e5d4ec5c1ca601a766c63133ae759651ae7be85
