gecko-dev/xpcom/base/nsError.h

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef nsError_h__
#define nsError_h__

#ifndef __cplusplus
#error nsError.h no longer supports C sources
#endif

#include "mozilla/Attributes.h"
#include "mozilla/Likely.h"

#include <stdint.h>

#define NS_ERROR_SEVERITY_SUCCESS       0
#define NS_ERROR_SEVERITY_ERROR         1

#include "ErrorList.h"

/**
 * @name Standard Error Handling Macros
 * @return 0 or 1 (false/true with bool type for C++)
 */

inline uint32_t
NS_FAILED_impl(nsresult aErr)
{
  return static_cast<uint32_t>(aErr) & 0x80000000;
}
#define NS_FAILED(_nsresult)    ((bool)MOZ_UNLIKELY(NS_FAILED_impl(_nsresult)))
#define NS_SUCCEEDED(_nsresult) ((bool)MOZ_LIKELY(!NS_FAILED_impl(_nsresult)))

/* Check that our enum type is actually uint32_t as expected */
static_assert(((nsresult)0) < ((nsresult)-1),
              "nsresult must be an unsigned type");
static_assert(sizeof(nsresult) == sizeof(uint32_t),
              "nsresult must be 32 bits");

#define MOZ_ALWAYS_SUCCEEDS(expr) MOZ_ALWAYS_TRUE(NS_SUCCEEDED(expr))

/**
 * @name Standard Error Generating Macros
 */

#define NS_ERROR_GENERATE(sev, module, code) \
  (nsresult)(((uint32_t)(sev) << 31) | \
             ((uint32_t)(module + NS_ERROR_MODULE_BASE_OFFSET) << 16) | \
             ((uint32_t)(code)))

#define NS_ERROR_GENERATE_SUCCESS(module, code) \
  NS_ERROR_GENERATE(NS_ERROR_SEVERITY_SUCCESS, module, code)

#define NS_ERROR_GENERATE_FAILURE(module, code) \
  NS_ERROR_GENERATE(NS_ERROR_SEVERITY_ERROR, module, code)

 /*
  * This will return the nsresult corresponding to the most recent NSPR failure
  * returned by PR_GetError.
  *
  ***********************************************************************
  *      Do not depend on this function. It will be going away!
  ***********************************************************************
  */
extern nsresult
NS_ErrorAccordingToNSPR();


/**
 * @name Standard Macros for retrieving error bits
 */

inline constexpr uint16_t
NS_ERROR_GET_CODE(nsresult aErr)
{
  return uint32_t(aErr) & 0xffff;
}
inline constexpr uint16_t
NS_ERROR_GET_MODULE(nsresult aErr)
{
  return ((uint32_t(aErr) >> 16) - NS_ERROR_MODULE_BASE_OFFSET) & 0x1fff;
}
inline bool
NS_ERROR_GET_SEVERITY(nsresult aErr)
{
  return uint32_t(aErr) >> 31;
}


#ifdef _MSC_VER
#pragma warning(disable: 4251) /* 'nsCOMPtr<class nsIInputStream>' needs to have dll-interface to be used by clients of class 'nsInputStream' */
#pragma warning(disable: 4275) /* non dll-interface class 'nsISupports' used as base for dll-interface class 'nsIRDFNode' */
#endif

#endif