147be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org/* 247be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org * Copyright 2014 The WebRTC Project Authors. All rights reserved. 347be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org * 447be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org * Use of this source code is governed by a BSD-style license 547be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org * that can be found in the LICENSE file in the root of the source 647be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org * tree. An additional intellectual property rights grant can be found 747be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org * in the file PATENTS. All contributing project authors may 847be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org * be found in the AUTHORS file in the root of the source tree. 947be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org */ 1047be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org 1147be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org// Borrowed from Chromium's src/base/numerics/safe_conversions.h. 1247be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org 1347be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org#ifndef WEBRTC_BASE_SAFE_CONVERSIONS_H_ 1447be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org#define WEBRTC_BASE_SAFE_CONVERSIONS_H_ 1547be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org 1647be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org#include <limits> 1747be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org 1847be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org#include "webrtc/base/common.h" 1947be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org#include "webrtc/base/logging.h" 2047be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org#include "webrtc/base/safe_conversions_impl.h" 2147be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org 2247be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.orgnamespace rtc { 2347be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org 2447be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.orginline void Check(bool condition) { 2547be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org if (!condition) { 2647be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org LOG(LS_ERROR) << "CHECK failed."; 2747be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org Break(); 2847be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org // The program should have crashed at this point. 2947be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org } 3047be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org} 3147be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org 3247be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org// Convenience function that returns true if the supplied value is in range 3347be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org// for the destination type. 3447be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.orgtemplate <typename Dst, typename Src> 3547be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.orginline bool IsValueInRangeForNumericType(Src value) { 3647be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org return internal::RangeCheck<Dst>(value) == internal::TYPE_VALID; 3747be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org} 3847be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org 3947be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org// checked_cast<> is analogous to static_cast<> for numeric types, 4047be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org// except that it CHECKs that the specified numeric conversion will not 4147be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org// overflow or underflow. NaN source will always trigger a CHECK. 4247be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.orgtemplate <typename Dst, typename Src> 4347be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.orginline Dst checked_cast(Src value) { 4447be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org Check(IsValueInRangeForNumericType<Dst>(value)); 4547be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org return static_cast<Dst>(value); 4647be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org} 4747be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org 4847be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org// saturated_cast<> is analogous to static_cast<> for numeric types, except 4947be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org// that the specified numeric conversion will saturate rather than overflow or 5047be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org// underflow. NaN assignment to an integral will trigger a CHECK condition. 5147be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.orgtemplate <typename Dst, typename Src> 5247be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.orginline Dst saturated_cast(Src value) { 5347be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org // Optimization for floating point values, which already saturate. 5447be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org if (std::numeric_limits<Dst>::is_iec559) 5547be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org return static_cast<Dst>(value); 5647be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org 5747be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org switch (internal::RangeCheck<Dst>(value)) { 5847be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org case internal::TYPE_VALID: 5947be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org return static_cast<Dst>(value); 6047be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org 6147be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org case internal::TYPE_UNDERFLOW: 6247be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org return std::numeric_limits<Dst>::min(); 6347be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org 6447be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org case internal::TYPE_OVERFLOW: 6547be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org return std::numeric_limits<Dst>::max(); 6647be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org 6747be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org // Should fail only on attempting to assign NaN to a saturated integer. 6847be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org case internal::TYPE_INVALID: 6947be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org Check(false); 7047be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org return std::numeric_limits<Dst>::max(); 7147be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org } 7247be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org 7347be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org Check(false); // NOTREACHED(); 7447be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org return static_cast<Dst>(value); 7547be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org} 7647be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org 7747be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org} // namespace rtc 7847be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org 7947be73b8629244d6bb63a28198f97f040ce53d21henrike@webrtc.org#endif // WEBRTC_BASE_SAFE_CONVERSIONS_H_ 80