sdk/lib/fidl/llcpp/display_error.cc

// Copyright 2022 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.

#include <lib/fidl/coding.h>
#include <lib/fidl/llcpp/internal/display_error.h>
#include <zircon/assert.h>

#include <cstdio>

namespace fidl::internal {

size_t fidl::internal::DisplayError<int32_t>::Format(const int32_t& value, char* destination,
                                                     size_t capacity) {
  int num_would_write = snprintf(destination, capacity, "int32_t (value: %d)", value);
  return static_cast<size_t>(num_would_write) >= capacity ? capacity - 1 : num_would_write;
}

size_t fidl::internal::DisplayError<uint32_t>::Format(const uint32_t& value, char* destination,
                                                      size_t capacity) {
  int num_would_write = snprintf(destination, capacity, "uint32_t (value: %u)", value);
  return static_cast<size_t>(num_would_write) >= capacity ? capacity - 1 : num_would_write;
}

size_t FormatApplicationError(uint32_t value, const char* member_name, const fidl_type_t* type,
                              char* destination, size_t capacity) {
  ZX_ASSERT(capacity >= 1);
  size_t used = fidl_format_type_name(type, destination, capacity);
  if (used == capacity) {
    destination[used - 1] = '\0';
    return used - 1;
  }
  destination = &destination[used];
  capacity -= used;

  int num_would_write;
  if (member_name == nullptr) {
    member_name = "[UNKNOWN]";
  }
  num_would_write = snprintf(destination, capacity, ".%s (value: %d)", member_name, value);
  size_t num_did_write =
      static_cast<size_t>(num_would_write) >= capacity ? capacity - 1 : num_would_write;
  return num_did_write + used;
}

}  // namespace fidl::internal