Source/wtf/CheckedArithmeticTest.cpp

/*
 * Copyright (C) 2011 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
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 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
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#include "config.h"
#include "wtf/CheckedArithmetic.h"

#include <gtest/gtest.h>

namespace WTF {

#define CheckedArithmeticTest(type, coerceLiteral, MixedSignednessTest) \
    TEST(CheckedArithmeticTest, Checked_##type) \
    { \
        Checked<type, RecordOverflow> value; \
        EXPECT_EQ(coerceLiteral(0), value.unsafeGet()); \
        EXPECT_EQ(std::numeric_limits<type>::max(), (value + std::numeric_limits<type>::max()).unsafeGet()); \
        EXPECT_EQ(std::numeric_limits<type>::max(), (std::numeric_limits<type>::max() + value).unsafeGet()); \
        EXPECT_EQ(std::numeric_limits<type>::min(), (value + std::numeric_limits<type>::min()).unsafeGet()); \
        EXPECT_EQ(std::numeric_limits<type>::min(), (std::numeric_limits<type>::min() + value).unsafeGet()); \
        EXPECT_EQ(coerceLiteral(0), (value * coerceLiteral(0)).unsafeGet()); \
        EXPECT_EQ(coerceLiteral(0), (coerceLiteral(0) * value).unsafeGet()); \
        EXPECT_EQ(coerceLiteral(0), (value * value).unsafeGet()); \
        EXPECT_EQ(coerceLiteral(0), (value - coerceLiteral(0)).unsafeGet()); \
        EXPECT_EQ(coerceLiteral(0), (coerceLiteral(0) - value).unsafeGet()); \
        EXPECT_EQ(coerceLiteral(0), (value - value).unsafeGet()); \
        EXPECT_EQ(coerceLiteral(0), (value++).unsafeGet()); \
        EXPECT_EQ(coerceLiteral(1), (value--).unsafeGet()); \
        EXPECT_EQ(coerceLiteral(1), (++value).unsafeGet()); \
        EXPECT_EQ(coerceLiteral(0), (--value).unsafeGet()); \
        EXPECT_EQ(coerceLiteral(10), (value += coerceLiteral(10)).unsafeGet()); \
        EXPECT_EQ(coerceLiteral(10), value.unsafeGet()); \
        EXPECT_EQ(coerceLiteral(100), (value *= coerceLiteral(10)).unsafeGet()); \
        EXPECT_EQ(coerceLiteral(100), value.unsafeGet()); \
        EXPECT_EQ(coerceLiteral(0), (value -= coerceLiteral(100)).unsafeGet()); \
        EXPECT_EQ(coerceLiteral(0), value.unsafeGet()); \
        value = 10; \
        EXPECT_EQ(coerceLiteral(10), value.unsafeGet()); \
        EXPECT_EQ(coerceLiteral(0), (value - coerceLiteral(10)).unsafeGet()); \
        EXPECT_EQ(coerceLiteral(10), value.unsafeGet()); \
        value = std::numeric_limits<type>::min(); \
        EXPECT_EQ(true, (Checked<type, RecordOverflow>(value - coerceLiteral(1))).hasOverflowed()); \
        EXPECT_EQ(true, !((value--).hasOverflowed())); \
        EXPECT_EQ(true, value.hasOverflowed()); \
        value = std::numeric_limits<type>::max(); \
        EXPECT_EQ(true, !value.hasOverflowed()); \
        EXPECT_EQ(true, (Checked<type, RecordOverflow>(value + coerceLiteral(1))).hasOverflowed()); \
        EXPECT_EQ(true, !(value++).hasOverflowed()); \
        EXPECT_EQ(true, value.hasOverflowed()); \
        value = std::numeric_limits<type>::max(); \
        EXPECT_EQ(true, (value += coerceLiteral(1)).hasOverflowed()); \
        EXPECT_EQ(true, value.hasOverflowed()); \
        value = 10; \
        type _value = 0; \
        EXPECT_EQ(true, CheckedState::DidNotOverflow == (value * Checked<type, RecordOverflow>(0)).safeGet(_value)); \
        _value = 0; \
        EXPECT_EQ(true, CheckedState::DidNotOverflow == (Checked<type, RecordOverflow>(0) * value).safeGet(_value)); \
        _value = 0; \
        EXPECT_EQ(true, CheckedState::DidOverflow == (value * Checked<type, RecordOverflow>(std::numeric_limits<type>::max())).safeGet(_value)); \
        _value = 0; \
        EXPECT_EQ(true, CheckedState::DidOverflow == (Checked<type, RecordOverflow>(std::numeric_limits<type>::max()) * value).safeGet(_value)); \
        value = 0; \
        _value = 0; \
        EXPECT_EQ(true, CheckedState::DidNotOverflow == (value * Checked<type, RecordOverflow>(std::numeric_limits<type>::max())).safeGet(_value)); \
        _value = 0; \
        EXPECT_EQ(true, CheckedState::DidNotOverflow == (Checked<type, RecordOverflow>(std::numeric_limits<type>::max()) * value).safeGet(_value)); \
        value = 1; \
        _value = 0; \
        EXPECT_EQ(true, CheckedState::DidNotOverflow == (value * Checked<type, RecordOverflow>(std::numeric_limits<type>::max())).safeGet(_value)); \
        _value = 0; \
        EXPECT_EQ(true, CheckedState::DidNotOverflow == (Checked<type, RecordOverflow>(std::numeric_limits<type>::max()) * value).safeGet(_value)); \
        _value = 0; \
        value = 0; \
        EXPECT_EQ(true, CheckedState::DidNotOverflow == (value * Checked<type, RecordOverflow>(std::numeric_limits<type>::max())).safeGet(_value)); \
        _value = 0; \
        EXPECT_EQ(true, CheckedState::DidNotOverflow == (Checked<type, RecordOverflow>(std::numeric_limits<type>::max()) * (type)0).safeGet(_value)); \
        _value = 0; \
        value = 1; \
        EXPECT_EQ(true, CheckedState::DidNotOverflow == (value * Checked<type, RecordOverflow>(std::numeric_limits<type>::max())).safeGet(_value)); \
        _value = 0; \
        EXPECT_EQ(true, CheckedState::DidNotOverflow == (Checked<type, RecordOverflow>(std::numeric_limits<type>::max()) * (type)1).safeGet(_value)); \
        _value = 0; \
        value = 2; \
        EXPECT_EQ(true, CheckedState::DidOverflow == (value * Checked<type, RecordOverflow>(std::numeric_limits<type>::max())).safeGet(_value)); \
        _value = 0; \
        EXPECT_EQ(true, CheckedState::DidOverflow == (Checked<type, RecordOverflow>(std::numeric_limits<type>::max()) * (type)2).safeGet(_value)); \
        value = 10; \
        EXPECT_EQ(true, (value * Checked<type, RecordOverflow>(std::numeric_limits<type>::max())).hasOverflowed()); \
        MixedSignednessTest(EXPECT_EQ(coerceLiteral(0), (value + -10).unsafeGet())); \
        MixedSignednessTest(EXPECT_EQ(0U, (value - 10U).unsafeGet())); \
        MixedSignednessTest(EXPECT_EQ(coerceLiteral(0), (-10 + value).unsafeGet())); \
        MixedSignednessTest(EXPECT_EQ(0U, (10U - value).unsafeGet())); \
        value = std::numeric_limits<type>::min(); \
        MixedSignednessTest(EXPECT_EQ(true, (Checked<type, RecordOverflow>(value - 1)).hasOverflowed())); \
        MixedSignednessTest(EXPECT_EQ(true, !(value--).hasOverflowed())); \
        MixedSignednessTest(EXPECT_EQ(true, value.hasOverflowed())); \
        value = std::numeric_limits<type>::max(); \
        MixedSignednessTest(EXPECT_EQ(true, !value.hasOverflowed())); \
        MixedSignednessTest(EXPECT_EQ(true, (Checked<type, RecordOverflow>(value + 1)).hasOverflowed())); \
        MixedSignednessTest(EXPECT_EQ(true, !(value++).hasOverflowed())); \
        MixedSignednessTest(EXPECT_EQ(true, value.hasOverflowed())); \
        value = std::numeric_limits<type>::max(); \
        MixedSignednessTest(EXPECT_EQ(true, (value += 1).hasOverflowed())); \
        MixedSignednessTest(EXPECT_EQ(true, value.hasOverflowed())); \
        value = std::numeric_limits<type>::min(); \
        MixedSignednessTest(EXPECT_EQ(true, (value - 1U).hasOverflowed())); \
        MixedSignednessTest(EXPECT_EQ(true, !(value--).hasOverflowed())); \
        MixedSignednessTest(EXPECT_EQ(true, value.hasOverflowed())); \
        value = std::numeric_limits<type>::max(); \
        MixedSignednessTest(EXPECT_EQ(true, !value.hasOverflowed())); \
        MixedSignednessTest(EXPECT_EQ(true, (Checked<type, RecordOverflow>(value + 1U)).hasOverflowed())); \
        MixedSignednessTest(EXPECT_EQ(true, !(value++).hasOverflowed())); \
        MixedSignednessTest(EXPECT_EQ(true, value.hasOverflowed())); \
        value = std::numeric_limits<type>::max(); \
        MixedSignednessTest(EXPECT_EQ(true, (value += 1U).hasOverflowed())); \
        MixedSignednessTest(EXPECT_EQ(true, value.hasOverflowed())); \
    }

#define CoerceLiteralToUnsigned(x) x##U
#define CoerceLiteralNop(x) x
#define AllowMixedSignednessTest(x) x
#define IgnoreMixedSignednessTest(x)
CheckedArithmeticTest(int8_t, CoerceLiteralNop, IgnoreMixedSignednessTest)
CheckedArithmeticTest(int16_t, CoerceLiteralNop, IgnoreMixedSignednessTest)
CheckedArithmeticTest(int32_t, CoerceLiteralNop, AllowMixedSignednessTest)
CheckedArithmeticTest(uint32_t, CoerceLiteralToUnsigned, AllowMixedSignednessTest)
CheckedArithmeticTest(int64_t, CoerceLiteralNop, IgnoreMixedSignednessTest)
CheckedArithmeticTest(uint64_t, CoerceLiteralToUnsigned, IgnoreMixedSignednessTest)

} // namespace WTF