cppcheck/lib/exprengine.cpp

/*
 * Cppcheck - A tool for static C/C++ code analysis
 * Copyright (C) 2007-2019 Cppcheck team.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "exprengine.h"
#include "astutils.h"
#include "settings.h"
#include "symboldatabase.h"
#include "tokenize.h"

#include <limits>
#include <memory>
#include <iostream>

std::string ExprEngine::str(int128_t value)
{
    std::ostringstream ostr;
#ifdef __GNUC__
    if (value == (int)value) {
        ostr << (int) value;
        return ostr.str();
    }
    if (value < 0) {
        ostr << "-";
        value = -value;
    }

    uint64_t high = value >> 64;
    uint64_t low = value;
    if (high > 0)
        ostr << "h" << std::hex << high << "l";
    ostr << std::hex << low;
#else
    ostr << value;
#endif
    return ostr.str();
}

static ExprEngine::ValuePtr getValueRangeFromValueType(const std::string &name, const ValueType *vt, const cppcheck::Platform &platform);

namespace {
    class TrackExecution {
    public:
        TrackExecution() : mDataIndex(0) {}
        std::map<const Token *, std::vector<std::string>> map;
        int getNewDataIndex() {
            return mDataIndex++;
        }

        void newValue(const Token *tok, ExprEngine::ValuePtr value) {
            if (!tok)
                return;
            if (!value)
                map[tok].push_back(tok->expressionString() + "=TODO_NO_VALUE");
            /*
                        else if (value->name[0] == '$')
                            map[tok].push_back(tok->expressionString() + "=(" + value->name + "," + value->getRange() + ")");
                        else
                            map[tok].push_back(tok->expressionString() + "=" + value->name);
            */
        }

        void state(const Token *tok, const std::string &s) {
            map[tok].push_back(s);
        }

        void print() {
            std::set<std::pair<int,int>> locations;
            for (auto it : map) {
                locations.insert(std::pair<int,int>(it.first->linenr(), it.first->column()));
            }
            for (const std::pair<int,int> &loc : locations) {
                int lineNumber = loc.first;
                int column = loc.second;
                for (auto &it : map) {
                    const Token *tok = it.first;
                    if (lineNumber != tok->linenr())
                        continue;
                    const std::vector<std::string> &dumps = it.second;
                    for (const std::string &dump : dumps)
                        std::cout << lineNumber << ":" << column << ": " << dump << "\n";
                }
            }
        }
    private:
        int mDataIndex;
    };

    class Data {
    public:
        Data(int *symbolValueIndex, const Tokenizer *tokenizer, const Settings *settings, const std::vector<ExprEngine::Callback> &callbacks, TrackExecution *trackExecution)
            : symbolValueIndex(symbolValueIndex)
            , tokenizer(tokenizer)
            , settings(settings)
            , callbacks(callbacks)
            , mTrackExecution(trackExecution)
            , mDataIndex(trackExecution->getNewDataIndex()) {}
        typedef std::map<nonneg int, std::shared_ptr<ExprEngine::Value>> Memory;
        Memory memory;
        int * const symbolValueIndex;
        const Tokenizer * const tokenizer;
        const Settings * const settings;
        const std::vector<ExprEngine::Callback> &callbacks;

        std::vector<Data> getData(const Token *cond, bool trueData) {
            std::vector<Data> ret;
            ret.push_back(Data(symbolValueIndex, tokenizer, settings, callbacks, mTrackExecution));
            for (Memory::const_iterator mem = memory.cbegin(); mem != memory.cend(); ++mem) {
                for (Data &data : ret)
                    data.memory[mem->first] = mem->second;

                if (cond->isComparisonOp() && cond->astOperand1()->varId() == mem->first && cond->astOperand2()->isNumber()) {
                    const int128_t rhsValue = MathLib::toLongNumber(cond->astOperand2()->str());
                    if (auto intRange = std::dynamic_pointer_cast<ExprEngine::IntRange>(mem->second)) {
                        if (cond->str() == ">") {
                            if (trueData) {
                                if (intRange->maxValue <= rhsValue)
                                    return std::vector<Data>();
                                auto val = std::make_shared<ExprEngine::IntRange>(getNewSymbolName(), rhsValue + 1, intRange->maxValue);
                                trackAssignment(cond, val);
                                ret[0].memory[mem->first] = val;
                            } else { /* if (!trueData) */
                                if (intRange->maxValue <= rhsValue)
                                    return std::vector<Data>();
                                auto val = std::make_shared<ExprEngine::IntRange>(getNewSymbolName(), intRange->minValue, rhsValue);
                                trackAssignment(cond, val);
                                ret[0].memory[mem->first] = val;
                            }
                        }
                    }
                }

                else if (cond->varId() == mem->first) {
                    if (auto intRange = std::dynamic_pointer_cast<ExprEngine::IntRange>(mem->second)) {
                        if (trueData) {
                            if (intRange->minValue == 0 && intRange->maxValue == 0)
                                return std::vector<Data>();
                            if (intRange->minValue < 0) {
                                auto val = std::make_shared<ExprEngine::IntRange>(getNewSymbolName(), intRange->minValue, -1);
                                trackAssignment(cond, val);
                                ret[0].memory[mem->first] = val;
                            }
                            if (intRange->maxValue > 0) {
                                auto val = std::make_shared<ExprEngine::IntRange>(getNewSymbolName(), 1, intRange->maxValue);
                                trackAssignment(cond, val);
                                if (intRange->minValue < 0) {
                                    // create additional intrange..
                                    ret.push_back(Data(symbolValueIndex, tokenizer, settings, callbacks, mTrackExecution));
                                    ret.back().memory = ret[0].memory;
                                }
                                ret[0].memory[mem->first] = val;
                            }
                        } else { /* if (!trueData) */
                            if (intRange->maxValue < 0 || intRange->minValue > 0)
                                return std::vector<Data>();

                            auto val = std::make_shared<ExprEngine::IntRange>(getNewSymbolName(), 0, 0);
                            trackAssignment(cond, val);
                            ret[0].memory[mem->first] = val;
                        }
                    }
                }
            }
            return ret;
        }

        std::string getNewSymbolName() {
            return "$" + std::to_string(++(*symbolValueIndex));
        }

        std::shared_ptr<ExprEngine::ArrayValue> getArrayValue(const Token *tok) {
            const Memory::iterator it = memory.find(tok->varId());
            if (it != memory.end())
                return std::dynamic_pointer_cast<ExprEngine::ArrayValue>(it->second);
            if (tok->varId() == 0)
                return std::shared_ptr<ExprEngine::ArrayValue>();
            unsigned int size = 1;
            for (const auto &dim : tok->variable()->dimensions())
                size *= dim.num;
            auto val = std::make_shared<ExprEngine::ArrayValue>(getNewSymbolName(), size);
            memory[tok->varId()] = val;
            return val;
        }

        ExprEngine::ValuePtr getValue(unsigned int varId, const ValueType *valueType, const Token *tok) {
            const Memory::const_iterator it = memory.find(varId);
            if (it != memory.end())
                return it->second;
            if (!valueType)
                return ExprEngine::ValuePtr();
            ExprEngine::ValuePtr value = getValueRangeFromValueType(getNewSymbolName(), valueType, *settings);
            if (value) {
                if (tok)
                    trackAssignment(tok, value);
                memory[varId] = value;
            }
            return value;
        }

        void trackAssignment(const Token *tok, ExprEngine::ValuePtr value) {
            return mTrackExecution->newValue(tok, value);
        }

        void trackProgramState(const Token *tok) {
            if (memory.empty())
                return;
            const SymbolDatabase * const symbolDatabase = tokenizer->getSymbolDatabase();
            std::ostringstream s;
            s << "{"; // << dataIndex << ":";
            for (auto mem : memory) {
                ExprEngine::ValuePtr value = mem.second;
                s << " " << symbolDatabase->getVariableFromVarId(mem.first)->name() << "=";
                if (!value)
                    s << "(null)";
                else if (value->name[0] == '$')
                    s << "(" << value->name << "," << value->getRange() << ")";
                else
                    s << value->name;
            }
            s << "}";
            mTrackExecution->state(tok, s.str());
        }
    private:
        TrackExecution * const mTrackExecution;
        const int mDataIndex;
    };
}

void ExprEngine::ArrayValue::assign(ExprEngine::ValuePtr index, ExprEngine::ValuePtr value)
{
    auto i1 = std::dynamic_pointer_cast<ExprEngine::IntRange>(index);
    if (i1) {
        if (i1->minValue == i1->maxValue && i1->minValue >= 0 && i1->maxValue < data.size())
            data[i1->minValue] = value;
    }
}

ExprEngine::ValuePtr ExprEngine::ArrayValue::read(ExprEngine::ValuePtr index)
{
    auto i1 = std::dynamic_pointer_cast<ExprEngine::IntRange>(index);
    if (i1) {
        if (i1->minValue == i1->maxValue && i1->minValue >= 0 && i1->maxValue < data.size())
            return data[i1->minValue];
    }
    return ExprEngine::ValuePtr();
}

std::string ExprEngine::ArrayValue::getRange() const
{
    std::ostringstream r;
    r << "[";
    for (size_t i = 0; i < data.size(); ++i) {
        r << (i==0?"":",") << data[i]->getRange();
    }
    r << "]";
    return r.str();
}

std::string ExprEngine::PointerValue::getRange() const
{
    std::string r;
    if (data)
        r = "->" + data->getRange();
    if (null)
        r += std::string(r.empty() ? "" : ",") + "null";
    if (uninitData)
        r += std::string(r.empty() ? "" : ",") + "->?";
    return r;
}

std::string ExprEngine::BinOpResult::getRange() const
{
    IntOrFloatValue minValue, maxValue;
    getRange(&minValue, &maxValue);
    const std::string s1 = minValue.isFloat()
                           ? std::to_string(minValue.floatValue)
                           : str(minValue.intValue);
    const std::string s2 = maxValue.isFloat()
                           ? std::to_string(maxValue.floatValue)
                           : str(maxValue.intValue);

    if (s1 == s2)
        return s1;
    return s1 + ":" + s2;
}

void ExprEngine::BinOpResult::getRange(ExprEngine::BinOpResult::IntOrFloatValue *minValue, ExprEngine::BinOpResult::IntOrFloatValue *maxValue) const
{
    std::map<ValuePtr, int> valueBit;
    // Assign a bit number for each leaf
    int bit = 0;
    for (ValuePtr v : mLeafs) {
        if (auto intRange = std::dynamic_pointer_cast<IntRange>(v)) {
            if (intRange->minValue == intRange->maxValue) {
                valueBit[v] = 30;
                continue;
            }
        }

        valueBit[v] = bit++;
    }

    if (bit > 24)
        throw std::runtime_error("Internal error: bits");

    for (int test = 0; test < (1 << bit); ++test) {
        auto result = evaluate(test, valueBit);
        if (test == 0)
            *minValue = *maxValue = result;
        else if (result.isFloat()) {
            if (result.floatValue < minValue->floatValue)
                *minValue = result;
            else if (result.floatValue > maxValue->floatValue)
                *maxValue = result;
        } else {
            if (result.intValue < minValue->intValue)
                *minValue = result;
            else if (result.intValue > maxValue->intValue)
                *maxValue = result;
        }
    }
}

std::string ExprEngine::IntegerTruncation::getRange() const
{
    return sign + std::to_string(bits) + "(" + inputValue->getRange() + ")";
}

bool ExprEngine::BinOpResult::isIntValueInRange(int value) const
{
    IntOrFloatValue minValue, maxValue;
    getRange(&minValue, &maxValue);
    return value >= minValue.intValue && value <= maxValue.intValue;
}

#define BINARY_OP(OP) \
    if (binop == #OP) { \
        struct ExprEngine::BinOpResult::IntOrFloatValue result(lhs); \
        if (lhs.isFloat()) \
        { result.type = lhs.type; result.floatValue = lhs.floatValue OP (rhs.isFloat() ? rhs.floatValue : rhs.intValue); } \
        else if (rhs.isFloat()) \
        { result.type = rhs.type; result.floatValue = lhs.intValue OP rhs.floatValue; } \
        else { result.type = lhs.type; result.intValue = lhs.intValue OP rhs.intValue; } \
        return result; \
    }

#define BINARY_INT_OP(OP) \
    if (binop == #OP) { \
        struct ExprEngine::BinOpResult::IntOrFloatValue result; \
        result.setIntValue(lhs.intValue OP rhs.intValue); \
        return result; \
    }

#define BINARY_OP_DIV(OP) \
    if (binop == #OP) { \
        struct ExprEngine::BinOpResult::IntOrFloatValue result(lhs); \
        if (lhs.isFloat()) \
        { result.type = lhs.type; result.floatValue = lhs.floatValue OP (rhs.isFloat() ? rhs.floatValue : rhs.intValue); } \
        else if (rhs.isFloat()) \
        { result.type = rhs.type; result.floatValue = lhs.intValue OP rhs.floatValue; } \
        else if (rhs.intValue != 0) { result.type = lhs.type; result.intValue = lhs.intValue OP rhs.intValue; } \
        return result; \
    }

ExprEngine::BinOpResult::IntOrFloatValue ExprEngine::BinOpResult::evaluate(int test, const std::map<ExprEngine::ValuePtr, int> &valueBit) const
{
    const ExprEngine::BinOpResult::IntOrFloatValue lhs = evaluateOperand(test, valueBit, op1);
    const ExprEngine::BinOpResult::IntOrFloatValue rhs = evaluateOperand(test, valueBit, op2);
    BINARY_OP(+)
    BINARY_OP(-)
    BINARY_OP(*)
    BINARY_OP_DIV(/)
    BINARY_INT_OP(&)
    BINARY_INT_OP(|)
    BINARY_INT_OP(^)
    BINARY_INT_OP(<<)
    BINARY_INT_OP(>>)

    if (binop == "%" && rhs.intValue != 0) {
        struct ExprEngine::BinOpResult::IntOrFloatValue result;
        result.setIntValue(lhs.intValue % rhs.intValue);
        return result;
    }

    throw std::runtime_error("Internal error: Unhandled operator;" + binop);
}

ExprEngine::BinOpResult::IntOrFloatValue ExprEngine::BinOpResult::evaluateOperand(int test, const std::map<ExprEngine::ValuePtr, int> &valueBit, ExprEngine::ValuePtr value) const
{
    auto binOpResult = std::dynamic_pointer_cast<ExprEngine::BinOpResult>(value);
    if (binOpResult)
        return binOpResult->evaluate(test, valueBit);

    auto it = valueBit.find(value);
    if (it == valueBit.end())
        throw std::runtime_error("Internal error: valueBit not set properly");

    bool valueType = test & (1 << it->second);
    if (auto intRange = std::dynamic_pointer_cast<IntRange>(value)) {
        ExprEngine::BinOpResult::IntOrFloatValue result;
        result.setIntValue(valueType ? intRange->minValue : intRange->maxValue);
        return result;
    }
    if (auto floatRange = std::dynamic_pointer_cast<FloatRange>(value)) {
        ExprEngine::BinOpResult::IntOrFloatValue result;
        result.setFloatValue(valueType ? floatRange->minValue : floatRange->maxValue);
        return result;
    }
    throw std::runtime_error("Internal error: Unhandled value:" + std::to_string((int)value->type()));
}

// Todo: This is taken from ValueFlow and modified.. we should reuse it
static int getIntBitsFromValueType(const ValueType *vt, const cppcheck::Platform &platform)
{
    if (!vt)
        return 0;

    switch (vt->type) {
    case ValueType::Type::BOOL:
        return 1;
    case ValueType::Type::CHAR:
        return platform.char_bit;
    case ValueType::Type::SHORT:
        return platform.short_bit;
    case ValueType::Type::INT:
        return platform.int_bit;
    case ValueType::Type::LONG:
        return platform.long_bit;
    case ValueType::Type::LONGLONG:
        return platform.long_long_bit;
    default:
        return 0;
    };
}

static ExprEngine::ValuePtr getValueRangeFromValueType(const std::string &name, const ValueType *vt, const cppcheck::Platform &platform)
{
    if (!vt || !(vt->isIntegral() || vt->isFloat()) || vt->pointer)
        return ExprEngine::ValuePtr();

    int bits = getIntBitsFromValueType(vt, platform);
    if (bits == 1) {
        return std::make_shared<ExprEngine::IntRange>(name, 0, 1);
    } else if (bits > 1) {
        if (vt->sign == ValueType::Sign::UNSIGNED) {
            return std::make_shared<ExprEngine::IntRange>(name, 0, ((int128_t)1 << bits) - 1);
        } else {
            return std::make_shared<ExprEngine::IntRange>(name, -((int128_t)1 << (bits - 1)), ((int128_t)1 << (bits - 1)) - 1);
        }
    }

    switch (vt->type) {
    case ValueType::Type::FLOAT:
        return std::make_shared<ExprEngine::FloatRange>(name, std::numeric_limits<float>::min(), std::numeric_limits<float>::max());
    case ValueType::Type::DOUBLE:
        return std::make_shared<ExprEngine::FloatRange>(name, std::numeric_limits<double>::min(), std::numeric_limits<double>::max());
    case ValueType::Type::LONGDOUBLE:
        return std::make_shared<ExprEngine::FloatRange>(name, std::numeric_limits<long double>::min(), std::numeric_limits<long double>::max());
    default:
        return ExprEngine::ValuePtr();
    };
}

static void call(const std::vector<ExprEngine::Callback> &callbacks, const Token *tok, ExprEngine::ValuePtr value)
{
    if (value) {
        for (ExprEngine::Callback f : callbacks) {
            f(tok, *value);
        }
    }
}

static ExprEngine::ValuePtr executeExpression(const Token *tok, Data &data);

static ExprEngine::ValuePtr executeReturn(const Token *tok, Data &data)
{
    ExprEngine::ValuePtr retval = executeExpression(tok->astOperand1(), data);
    call(data.callbacks, tok, retval);
    return retval;
}

static ExprEngine::ValuePtr truncateValue(ExprEngine::ValuePtr val, const ValueType *valueType, Data &data)
{
    if (!valueType)
        return val;
    if (valueType->pointer != 0)
        return val;
    if (!valueType->isIntegral())
        return val; // TODO

    int bits = getIntBitsFromValueType(valueType, *data.settings);
    if (bits == 0)
        // TODO
        return val;

    if (auto range = std::dynamic_pointer_cast<ExprEngine::IntRange>(val)) {

        if (range->minValue == range->maxValue) {
            int128_t newValue = range->minValue;
            newValue = newValue & (((int128_t)1 << bits) - 1);
            // TODO: Sign extension
            if (newValue == range->minValue)
                return val;
            return std::make_shared<ExprEngine::IntRange>(ExprEngine::str(newValue), newValue, newValue);
        }
        if (auto typeRange = getValueRangeFromValueType("", valueType, *data.settings)) {
            auto typeIntRange = std::dynamic_pointer_cast<ExprEngine::IntRange>(typeRange);
            if (typeIntRange) {
                if (range->minValue >= typeIntRange->minValue && range->maxValue <= typeIntRange->maxValue)
                    return val;
            }
        }

        return std::make_shared<ExprEngine::IntegerTruncation>(data.getNewSymbolName(), val, bits, valueType->sign == ValueType::Sign::SIGNED ? 's' : 'u');
    }
    // TODO
    return val;
}

static ExprEngine::ValuePtr executeAssign(const Token *tok, Data &data)
{
    ExprEngine::ValuePtr rhsValue = executeExpression(tok->astOperand2(), data);
    ExprEngine::ValuePtr assignValue;
    if (tok->str() == "=")
        assignValue = rhsValue;
    else {
        // "+=" => "+"
        std::string binop(tok->str());
        binop = binop.substr(0, binop.size() - 1);
        ExprEngine::ValuePtr lhsValue = executeExpression(tok->astOperand1(), data);
        assignValue = std::make_shared<ExprEngine::BinOpResult>(binop, lhsValue, rhsValue);
    }

    const Token *lhsToken = tok->astOperand1();
    assignValue = truncateValue(assignValue, lhsToken->valueType(), data);
    call(data.callbacks, tok, assignValue);

    data.trackAssignment(lhsToken, assignValue);
    if (lhsToken->varId() > 0) {
        data.memory[lhsToken->varId()] = assignValue;
    } else if (lhsToken->str() == "[") {
        auto arrayValue = data.getArrayValue(lhsToken->astOperand1());
        if (arrayValue) {
            // Is it array initialization?
            const Token *arrayInit = lhsToken->astOperand1();
            if (arrayInit && arrayInit->variable() && arrayInit->variable()->nameToken() == arrayInit) {
                if (auto strval = std::dynamic_pointer_cast<ExprEngine::StringLiteralValue>(assignValue)) {
                    for (size_t i = 0; i < strval->size(); ++i) {
                        uint8_t c = strval->string[i];
                        arrayValue->data[i] = std::make_shared<ExprEngine::IntRange>(std::to_string(int(c)),c,c);
                    }
                    auto v0 = std::make_shared<ExprEngine::IntRange>("0",0,0);
                    for (size_t i = strval->size(); i < arrayValue->data.size(); ++i)
                        arrayValue->data[i] = v0;
                }
            } else {
                auto indexValue = executeExpression(lhsToken->astOperand2(), data);
                arrayValue->assign(indexValue, assignValue);
            }
        }
    } else if (lhsToken->isUnaryOp("*")) {
        auto pval = executeExpression(lhsToken->astOperand1(), data);
        if (pval && pval->type() == ExprEngine::ValueType::AddressOfValue) {
            auto val = std::dynamic_pointer_cast<ExprEngine::AddressOfValue>(pval);
            if (val)
                data.memory[val->varId] = assignValue;
        } else if (pval && pval->type() == ExprEngine::ValueType::BinOpResult) {
            auto b = std::dynamic_pointer_cast<ExprEngine::BinOpResult>(pval);
            if (b && b->binop == "+") {
                std::shared_ptr<ExprEngine::ArrayValue> arr;
                ExprEngine::ValuePtr offset;
                if (b->op1->type() == ExprEngine::ValueType::ArrayValue) {
                    arr = std::dynamic_pointer_cast<ExprEngine::ArrayValue>(b->op1);
                    offset = b->op2;
                } else {
                    arr = std::dynamic_pointer_cast<ExprEngine::ArrayValue>(b->op2);
                    offset = b->op1;
                }
                if (arr && offset) {
                    arr->assign(offset, assignValue);
                }
            }
        }
    }
    return assignValue;
}

static ExprEngine::ValuePtr executeFunctionCall(const Token *tok, Data &data)
{
    for (const Token *argtok : getArguments(tok)) {
        auto val = executeExpression(argtok, data);
        if (!argtok->valueType() || (argtok->valueType()->constness & 1) == 1)
            continue;
        if (auto arrayValue = std::dynamic_pointer_cast<ExprEngine::ArrayValue>(val)) {
            ValueType vt(*argtok->valueType());
            vt.pointer = 0;
            auto anyVal = getValueRangeFromValueType(data.getNewSymbolName(), &vt, *data.settings);
            for (int i = 0; i < arrayValue->data.size(); ++i)
                arrayValue->data[i] = anyVal;
        } else if (auto addressOf = std::dynamic_pointer_cast<ExprEngine::AddressOfValue>(val)) {
            ValueType vt(*argtok->valueType());
            vt.pointer = 0;
            if (vt.isIntegral() && argtok->valueType()->pointer == 1)
                data.memory[addressOf->varId] = getValueRangeFromValueType(data.getNewSymbolName(), &vt, *data.settings);
        }
    }
    auto val = getValueRangeFromValueType(data.getNewSymbolName(), tok->valueType(), *data.settings);
    call(data.callbacks, tok, val);
    return val;
}

static ExprEngine::ValuePtr executeArrayIndex(const Token *tok, Data &data)
{
    auto arrayValue = data.getArrayValue(tok->astOperand1());
    if (arrayValue) {
        auto indexValue = executeExpression(tok->astOperand2(), data);
        auto value = arrayValue->read(indexValue);
        call(data.callbacks, tok, value);
        return value;
    }
    return ExprEngine::ValuePtr();
}

static ExprEngine::ValuePtr executeDot(const Token *tok, Data &data)
{
    if (!tok->astOperand1() || !tok->astOperand1()->varId())
        return ExprEngine::ValuePtr();
    std::shared_ptr<ExprEngine::StructValue> structValue = std::dynamic_pointer_cast<ExprEngine::StructValue>(data.getValue(tok->astOperand1()->varId(), nullptr, nullptr));
    if (!structValue)
        return ExprEngine::ValuePtr();
    return structValue->getValueOfMember(tok->astOperand2()->str());
}

static ExprEngine::ValuePtr executeBinaryOp(const Token *tok, Data &data)
{
    ExprEngine::ValuePtr v1 = executeExpression(tok->astOperand1(), data);
    ExprEngine::ValuePtr v2 = executeExpression(tok->astOperand2(), data);
    if (v1 && v2) {
        auto result = std::make_shared<ExprEngine::BinOpResult>(tok->str(), v1, v2);
        call(data.callbacks, tok, result);
        return result;
    }
    return ExprEngine::ValuePtr();
}

static ExprEngine::ValuePtr executeAddressOf(const Token *tok, Data &data)
{
    auto addr = std::make_shared<ExprEngine::AddressOfValue>(data.getNewSymbolName(), tok->astOperand1()->varId());
    call(data.callbacks, tok, addr);
    return addr;
}

static ExprEngine::ValuePtr executeDeref(const Token *tok, Data &data)
{
    ExprEngine::ValuePtr pval = executeExpression(tok->astOperand1(), data);
    if (pval) {
        auto addressOf = std::dynamic_pointer_cast<ExprEngine::AddressOfValue>(pval);
        if (addressOf) {
            auto val = data.getValue(addressOf->varId, tok->valueType(), tok);
            call(data.callbacks, tok, val);
            return val;
        }
        auto pointer = std::dynamic_pointer_cast<ExprEngine::PointerValue>(pval);
        if (pointer) {
            auto val = pointer->data;
            call(data.callbacks, tok, val);
            return val;
        }
    }
    return ExprEngine::ValuePtr();
}

static ExprEngine::ValuePtr executeVariable(const Token *tok, Data &data)
{
    auto val = data.getValue(tok->varId(), tok->valueType(), tok);
    call(data.callbacks, tok, val);
    return val;
}

static ExprEngine::ValuePtr executeKnownMacro(const Token *tok, Data &data)
{
    auto val = std::make_shared<ExprEngine::IntRange>(data.getNewSymbolName(), tok->getKnownIntValue(), tok->getKnownIntValue());
    call(data.callbacks, tok, val);
    return val;
}

static ExprEngine::ValuePtr executeNumber(const Token *tok)
{
    if (tok->valueType()->isFloat()) {
        long double value = MathLib::toDoubleNumber(tok->str());
        return std::make_shared<ExprEngine::FloatRange>(tok->str(), value, value);
    }
    int128_t value = MathLib::toLongNumber(tok->str());
    return std::make_shared<ExprEngine::IntRange>(tok->str(), value, value);
}

static ExprEngine::ValuePtr executeStringLiteral(const Token *tok, Data &data)
{
    std::string s = tok->str();
    return std::make_shared<ExprEngine::StringLiteralValue>(data.getNewSymbolName(), s.substr(1, s.size()-2));
}

static ExprEngine::ValuePtr executeExpression(const Token *tok, Data &data)
{
    if (tok->str() == "return")
        return executeReturn(tok, data);

    if (tok->isAssignmentOp())
        // TODO: Handle more operators
        return executeAssign(tok, data);

    if (tok->astOperand1() && tok->astOperand2() && tok->str() == "[")
        return executeArrayIndex(tok, data);

    if (tok->str() == "(" && !tok->isCast())
        return executeFunctionCall(tok, data);

    if (tok->str() == ".")
        return executeDot(tok, data);

    if (tok->astOperand1() && tok->astOperand2())
        return executeBinaryOp(tok, data);

    if (tok->isUnaryOp("&") && Token::Match(tok->astOperand1(), "%var%"))
        return executeAddressOf(tok, data);

    if (tok->isUnaryOp("*"))
        return executeDeref(tok, data);

    if (tok->varId())
        return executeVariable(tok, data);

    if (tok->isName() && tok->hasKnownIntValue())
        return executeKnownMacro(tok, data);

    if (tok->isNumber())
        return executeNumber(tok);

    if (tok->tokType() == Token::Type::eString)
        return executeStringLiteral(tok, data);

    return ExprEngine::ValuePtr();
}

static void execute(const Token *start, const Token *end, Data &data)
{
    for (const Token *tok = start; tok != end; tok = tok->next()) {
        if (Token::Match(tok, "[;{}]"))
            data.trackProgramState(tok);
        if (tok->variable() && tok->variable()->nameToken() == tok) {
            if (tok->variable()->isArray() && tok->variable()->dimensions().size() == 1 && tok->variable()->dimensions()[0].known) {
                data.memory[tok->varId()] = std::make_shared<ExprEngine::ArrayValue>(data.getNewSymbolName(), tok->variable()->dimension(0));
            }
            if (Token::Match(tok, "%name% ["))
                tok = tok->linkAt(1);
        }
        if (!tok->astParent() && (tok->astOperand1() || tok->astOperand2()))
            executeExpression(tok, data);

        if (Token::simpleMatch(tok, "if (")) {
            const Token *cond = tok->next()->astOperand2();
            /*const ExprEngine::ValuePtr condValue =*/ executeExpression(cond,data);
            std::vector<Data> trueData = data.getData(cond, true);
            std::vector<Data> falseData = data.getData(cond, false);
            const Token *thenStart = tok->linkAt(1)->next();
            const Token *thenEnd = thenStart->link();
            for (Data &d : trueData)
                execute(thenStart->next(), end, d);
            if (Token::simpleMatch(thenEnd, "} else {")) {
                const Token *elseStart = thenEnd->tokAt(2);
                for (Data &d : falseData)
                    execute(elseStart->next(), end, d);
            } else {
                for (Data &d : falseData)
                    execute(thenEnd->next(), end, d);
            }
            return;
        }

        if (Token::simpleMatch(tok, "} else {"))
            tok = tok->linkAt(2);
    }
}

void ExprEngine::executeAllFunctions(const Tokenizer *tokenizer, const Settings *settings, const std::vector<ExprEngine::Callback> &callbacks)
{
    const SymbolDatabase *symbolDatabase = tokenizer->getSymbolDatabase();
    for (const Scope *functionScope : symbolDatabase->functionScopes) {
        executeFunction(functionScope, tokenizer, settings, callbacks);
    }
}

static ExprEngine::ValuePtr createVariableValue(const Variable &var, Data &data);

static ExprEngine::ValuePtr createStructVal(const Scope *structScope, Data &data)
{
    if (!structScope)
        return ExprEngine::ValuePtr();
    std::shared_ptr<ExprEngine::StructValue> structValue = std::make_shared<ExprEngine::StructValue>(data.getNewSymbolName());
    for (const Variable &member : structScope->varlist) {
        ExprEngine::ValuePtr memberValue = createVariableValue(member, data);
        if (memberValue)
            structValue->member[member.name()] = memberValue;
    }
    return structValue;
}

static ExprEngine::ValuePtr createVariableValue(const Variable &var, Data &data)
{
    if (!var.nameToken())
        return ExprEngine::ValuePtr();
    const ValueType *valueType = var.valueType();
    if (!valueType || valueType->type == ValueType::Type::UNKNOWN_TYPE)
        valueType = var.nameToken()->valueType();
    if (!valueType || valueType->type == ValueType::Type::UNKNOWN_TYPE)
        return ExprEngine::ValuePtr();

    if (valueType->pointer > 0) {
        ValueType vt(*valueType);
        vt.pointer = 0;
        auto range = getValueRangeFromValueType(data.getNewSymbolName(), &vt, *data.settings);
        return std::make_shared<ExprEngine::PointerValue>(data.getNewSymbolName(), range, true, true);
    }
    if (valueType->isIntegral())
        return getValueRangeFromValueType(data.getNewSymbolName(), valueType, *data.settings);
    if (valueType->type == ValueType::Type::RECORD)
        return createStructVal(valueType->typeScope, data);
    if (valueType->smartPointerType) {
        auto structValue = createStructVal(valueType->smartPointerType->classScope, data);
        return std::make_shared<ExprEngine::PointerValue>(data.getNewSymbolName(), structValue, true, false);
    }
    return ExprEngine::ValuePtr();
}

void ExprEngine::executeFunction(const Scope *functionScope, const Tokenizer *tokenizer, const Settings *settings, const std::vector<ExprEngine::Callback> &callbacks)
{
    if (!functionScope->bodyStart)
        return;
    const Function *function = functionScope->function;
    if (!function)
        return;
    if (functionScope->bodyStart->fileIndex() > 0)
        // TODO.. what about functions in headers?
        return;

    int symbolValueIndex = 0;
    TrackExecution trackExecution;
    Data data(&symbolValueIndex, tokenizer, settings, callbacks, &trackExecution);

    for (const Variable &arg : function->argumentList) {
        ValuePtr val = createVariableValue(arg, data);
        if (val) {
            data.trackAssignment(arg.nameToken(), val);
            data.memory[arg.declarationId()] = val;
        }
    }

    execute(functionScope->bodyStart, functionScope->bodyEnd, data);

    if (settings->verification) {
        // TODO generate better output!!
        trackExecution.print();
    }
}

void ExprEngine::runChecks(ErrorLogger *errorLogger, const Tokenizer *tokenizer, const Settings *settings)
{
    std::function<void(const Token *, const ExprEngine::Value &)> divByZero = [&](const Token *tok, const ExprEngine::Value &value) {
        if (!Token::simpleMatch(tok->astParent(), "/"))
            return;
        if (tok->astParent()->astOperand2() == tok && value.isIntValueInRange(0)) {
            std::list<const Token*> callstack{tok->astParent()};
            ErrorLogger::ErrorMessage errmsg(callstack, &tokenizer->list, Severity::SeverityType::error, "verificationDivByZero", "Division by zero", false);
            errorLogger->reportErr(errmsg);
        }
    };

    std::vector<ExprEngine::Callback> callbacks;
    callbacks.push_back(divByZero);
    ExprEngine::executeAllFunctions(tokenizer, settings, callbacks);
}