text: /*
   *
   * Copyright 2016 gRPC authors.
   *
   * 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 <grpc/support/port_platform.h>
  
  #include "src/core/lib/transport/error_utils.h"
  
  #include <grpc/support/string_util.h>
  
  #include "src/core/lib/gprpp/status_helper.h"
  #include "src/core/lib/iomgr/error_internal.h"
  #include "src/core/lib/slice/slice_internal.h"
  #include "src/core/lib/transport/status_conversion.h"
  
  static grpc_error_handle recursively_find_error_with_field(
      grpc_error_handle error, grpc_error_ints which) {
    intptr_t unused;
    // If the error itself has a status code, return it.
    if (grpc_error_get_int(error, which, &unused)) {
      return error;
    }
  #ifdef GRPC_ERROR_IS_ABSEIL_STATUS
    std::vector<absl::Status> children = grpc_core::StatusGetChildren(error);
    for (auto child : children) {
      grpc_error_handle result = recursively_find_error_with_field(child, which);
      if (result != GRPC_ERROR_NONE) return result;
    }
  #else
    if (grpc_error_is_special(error)) return GRPC_ERROR_NONE;
    // Otherwise, search through its children.
    uint8_t slot = error->first_err;
    while (slot != UINT8_MAX) {
      grpc_linked_error* lerr =
          reinterpret_cast<grpc_linked_error*>(error->arena + slot);
      grpc_error_handle result =
          recursively_find_error_with_field(lerr->err, which);
      if (result) return result;
      slot = lerr->next;
    }
  #endif
    return GRPC_ERROR_NONE;
  }
  
  void grpc_error_get_status(grpc_error_handle error, grpc_millis deadline,
                             grpc_status_code* code, grpc_slice* slice,
                             grpc_http2_error_code* http_error,
                             const char** error_string) {
    // Fast path: We expect no error.
    if (GPR_LIKELY(error == GRPC_ERROR_NONE)) {
      if (code != nullptr) *code = GRPC_STATUS_OK;
      if (slice != nullptr) {
        // Normally, we call grpc_error_get_str(
        //   error, GRPC_ERROR_STR_GRPC_MESSAGE, slice).
        // We can fastpath since we know that:
        // 1) Error is null
        // 2) which == GRPC_ERROR_STR_GRPC_MESSAGE
        // 3) The resulting slice is statically known.
        // 4) Said resulting slice is of length 0 ("").
        // This means 3 movs, instead of 10s of instructions and a strlen.
        *slice = grpc_core::ExternallyManagedSlice("");
      }
      if (http_error != nullptr) {
        *http_error = GRPC_HTTP2_NO_ERROR;
      }
      return;
    }
  
    // Start with the parent error and recurse through the tree of children
    // until we find the first one that has a status code.
    grpc_error_handle found_error =
        recursively_find_error_with_field(error, GRPC_ERROR_INT_GRPC_STATUS);
    if (found_error == GRPC_ERROR_NONE) {
      /// If no grpc-status exists, retry through the tree to find a http2 error
      /// code
      found_error =
          recursively_find_error_with_field(error, GRPC_ERROR_INT_HTTP2_ERROR);
    }
  
    // If we found an error with a status code above, use that; otherwise,
    // fall back to using the parent error.
    if (found_error == GRPC_ERROR_NONE) found_error = error;
  
    grpc_status_code status = GRPC_STATUS_UNKNOWN;
    intptr_t integer;
    if (grpc_error_get_int(found_error, GRPC_ERROR_INT_GRPC_STATUS, &integer)) {
      status = static_cast<grpc_status_code>(integer);
    } else if (grpc_error_get_int(found_error, GRPC_ERROR_INT_HTTP2_ERROR,
                                  &integer)) {
      status = grpc_http2_error_to_grpc_status(
          static_cast<grpc_http2_error_code>(integer), deadline);
    }
    if (code != nullptr) *code = status;
  
    if (error_string != nullptr && status != GRPC_STATUS_OK) {
      *error_string = gpr_strdup(grpc_error_std_string(error).c_str());
    }
  
    if (http_error != nullptr) {
      if (grpc_error_get_int(found_error, GRPC_ERROR_INT_HTTP2_ERROR, &integer)) {
        *http_error = static_cast<grpc_http2_error_code>(integer);
      } else if (grpc_error_get_int(found_error, GRPC_ERROR_INT_GRPC_STATUS,
                                    &integer)) {
        *http_error =
            grpc_status_to_http2_error(static_cast<grpc_status_code>(integer));
      } else {
        *http_error = found_error == GRPC_ERROR_NONE ? GRPC_HTTP2_NO_ERROR
                                                     : GRPC_HTTP2_INTERNAL_ERROR;
      }
    }
  
    // If the error has a status message, use it.  Otherwise, fall back to
    // the error description.
    if (slice != nullptr) {
      if (!grpc_error_get_str(found_error, GRPC_ERROR_STR_GRPC_MESSAGE, slice)) {
        if (!grpc_error_get_str(found_error, GRPC_ERROR_STR_DESCRIPTION, slice)) {
  #ifdef GRPC_ERROR_IS_ABSEIL_STATUS
          *slice =
              grpc_slice_from_copied_string(grpc_error_std_string(error).c_str());
  #else
          *slice = grpc_slice_from_static_string("unknown error");
  #endif
        }
      }
    }
  }
  
  absl::Status grpc_error_to_absl_status(grpc_error_handle error) {
    grpc_status_code status;
    // TODO(yashykt): This should be updated once we decide on how to use the
    // absl::Status payload to capture all the contents of grpc_error.
    grpc_slice message;
    grpc_error_get_status(error, GRPC_MILLIS_INF_FUTURE, &status, &message,
                          nullptr /* http_error */, nullptr /* error_string */);
    return absl::Status(static_cast<absl::StatusCode>(status),
                        absl::string_view(reinterpret_cast<const char*>(
                                              GRPC_SLICE_START_PTR(message)),
                                          GRPC_SLICE_LENGTH(message)));
  }
  
  grpc_error_handle absl_status_to_grpc_error(absl::Status status) {
    // Special error checks
    if (status.ok()) {
      return GRPC_ERROR_NONE;
    }
    return grpc_error_set_int(
        GRPC_ERROR_CREATE_FROM_STRING_VIEW(status.message()),
        GRPC_ERROR_INT_GRPC_STATUS, static_cast<grpc_status_code>(status.code()));
  }
  
  bool grpc_error_has_clear_grpc_status(grpc_error_handle error) {
    intptr_t unused;
    if (grpc_error_get_int(error, GRPC_ERROR_INT_GRPC_STATUS, &unused)) {
      return true;
    }
  #ifdef GRPC_ERROR_IS_ABSEIL_STATUS
    std::vector<absl::Status> children = grpc_core::StatusGetChildren(error);
    for (auto child : children) {
      if (grpc_error_has_clear_grpc_status(child)) {
        return true;
      }
    }
  #else
    uint8_t slot = error->first_err;
    while (slot != UINT8_MAX) {
      grpc_linked_error* lerr =
          reinterpret_cast<grpc_linked_error*>(error->arena + slot);
      if (grpc_error_has_clear_grpc_status(lerr->err)) {
        return true;
      }
      slot = lerr->next;
    }
  #endif
    return false;
  }
  