/*
 * 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 symbolRange(const Token *tok, ExprEngine::ValuePtr value) {
            if (!tok || !value)
                return;
            const std::string &symbolicExpression = value->getSymbolicExpression();
            if (symbolicExpression[0] != '$')
                return;
            if (mSymbols.find(symbolicExpression) != mSymbols.end())
                return;
            mSymbols.insert(symbolicExpression);
            map[tok].push_back(symbolicExpression + "=" + value->getRange());

        }

        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;
                    if (column != tok->column())
                        continue;
                    const std::vector<std::string> &dumps = it.second;
                    for (const std::string &dump : dumps)
                        std::cout << lineNumber << ":" << column << ": " << dump << "\n";
                }
            }
        }
    private:
        int mDataIndex;
        std::set<std::string> mSymbols;
    };

    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;

        void assignValue(const Token *tok, unsigned int varId, ExprEngine::ValuePtr value) {
            mTrackExecution->symbolRange(tok, value);
            if (value) {
                if (auto arr = std::dynamic_pointer_cast<ExprEngine::ArrayValue>(value)) {
                    mTrackExecution->symbolRange(tok, arr->size);
                    for (const auto &indexAndValue: arr->data)
                        mTrackExecution->symbolRange(tok, indexAndValue.value);
                } else if (auto s = std::dynamic_pointer_cast<ExprEngine::StructValue>(value)) {
                    for (const auto &m: s->member)
                        mTrackExecution->symbolRange(tok, m.second);
                }
            }
            memory[varId] = value;
        }

        void assignStructMember(const Token *tok, ExprEngine::StructValue *structVal, const std::string &memberName, ExprEngine::ValuePtr value) {
            mTrackExecution->symbolRange(tok, value);
            structVal->member[memberName] = value;
        }

        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);
                                ret[0].assignValue(cond, 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);
                                ret[0].assignValue(cond, 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);
                                ret[0].assignValue(cond, mem->first, val);
                            }
                            if (intRange->maxValue > 0) {
                                auto val = std::make_shared<ExprEngine::IntRange>(getNewSymbolName(), 1, intRange->maxValue);
                                if (intRange->minValue < 0) {
                                    // create additional intrange..
                                    ret.push_back(Data(symbolValueIndex, tokenizer, settings, callbacks, mTrackExecution));
                                    ret.back().memory = ret[0].memory;
                                }
                                ret[0].assignValue(cond, 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);
                            ret[0].assignValue(cond, 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>();
            auto val = std::make_shared<ExprEngine::ArrayValue>(getNewSymbolName(), tok->variable());
            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) {
                assignValue(tok, varId, value);
            }
            return 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] == '$' && value->getSymbolicExpression() != value->name)
                    s << "(" << value->name << "," << value->getSymbolicExpression() << ")";
                else
                    s << value->name;
            }
            s << "}";
            mTrackExecution->state(tok, s.str());
        }
    private:
        TrackExecution * const mTrackExecution;
        const int mDataIndex;
    };
}

static ExprEngine::ValuePtr simplifyValue(ExprEngine::ValuePtr origValue)
{
    auto b = std::dynamic_pointer_cast<ExprEngine::BinOpResult>(origValue);
    if (!b)
        return origValue;
    if (!b->op1 || !b->op2)
        return origValue;
    auto intRange1 = std::dynamic_pointer_cast<ExprEngine::IntRange>(b->op1);
    auto intRange2 = std::dynamic_pointer_cast<ExprEngine::IntRange>(b->op1);
    if (intRange1 && intRange2 && intRange1->minValue == intRange1->maxValue && intRange2->minValue == intRange2->maxValue) {
        const std::string &binop = b->binop;
        int128_t v;
        if (binop == "+")
            v = intRange1->minValue + intRange2->minValue;
        else if (binop == "-")
            v = intRange1->minValue - intRange2->minValue;
        else if (binop == "*")
            v = intRange1->minValue * intRange2->minValue;
        else if (binop == "/" && intRange2->minValue != 0)
            v = intRange1->minValue / intRange2->minValue;
        else if (binop == "%" && intRange2->minValue != 0)
            v = intRange1->minValue % intRange2->minValue;
        else
            return origValue;
        return std::make_shared<ExprEngine::IntRange>(ExprEngine::str(v), v, v);
    }
    return origValue;
}


ExprEngine::ArrayValue::ArrayValue(const std::string &name, ExprEngine::ValuePtr size, ExprEngine::ValuePtr value)
    : Value(name, ExprEngine::ValueType::ArrayValue)
    , size(size)
{
    assign(ExprEngine::ValuePtr(), value);
}

ExprEngine::ArrayValue::ArrayValue(const std::string &name, const Variable *var)
    : Value(name, ExprEngine::ValueType::ArrayValue)
{
    if (var) {
        int sz = 1;
        for (const auto &dim : var->dimensions()) {
            if (!dim.known) {
                sz = -1;
                break;
            }
            sz *= dim.num;
        }
        if (sz >= 1)
            size = std::make_shared<ExprEngine::IntRange>(std::to_string(sz), sz, sz);
    }
    assign(ExprEngine::ValuePtr(), std::make_shared<ExprEngine::UninitValue>());
}

void ExprEngine::ArrayValue::assign(ExprEngine::ValuePtr index, ExprEngine::ValuePtr value)
{
    if (!index)
        data.clear();
    if (value) {
        ExprEngine::ArrayValue::IndexAndValue indexAndValue = {index, value};
        data.push_back(indexAndValue);
    }
}

void ExprEngine::ArrayValue::clear()
{
    data.clear();
    ExprEngine::ArrayValue::IndexAndValue indexAndValue = {
        ExprEngine::ValuePtr(), std::make_shared<ExprEngine::IntRange>("0", 0, 0)
    };
    data.push_back(indexAndValue);
}

static bool isEqual(ExprEngine::ValuePtr v1, ExprEngine::ValuePtr v2)
{
    if (!v1 || !v2)
        return !v1 && !v2;
    return v1->name == v2->name;
}

static bool isNonOverlapping(ExprEngine::ValuePtr v1, ExprEngine::ValuePtr v2)
{
    if (!v1 || !v2)
        return false; // Don't know!
    auto intRange1 = std::dynamic_pointer_cast<ExprEngine::IntRange>(v1);
    auto intRange2 = std::dynamic_pointer_cast<ExprEngine::IntRange>(v2);
    if (intRange1 && intRange2 && (intRange1->minValue > intRange2->maxValue || intRange1->maxValue < intRange2->maxValue))
        return true;
    return false;
}

ExprEngine::ConditionalValue::Vector ExprEngine::ArrayValue::read(ExprEngine::ValuePtr index) const
{
    ExprEngine::ConditionalValue::Vector ret;
    for (const auto indexAndValue : data) {
        if (isEqual(index, indexAndValue.index))
            ret.clear();
        if (isNonOverlapping(index, indexAndValue.index))
            continue;
        // Array contains string literal data...
        if (!indexAndValue.index && indexAndValue.value->type == ExprEngine::ValueType::StringLiteralValue) {
            auto stringLiteral = std::dynamic_pointer_cast<ExprEngine::StringLiteralValue>(indexAndValue.value);
            if (!stringLiteral) {
                ret.push_back(std::pair<ValuePtr,ValuePtr>(indexAndValue.index, std::make_shared<ExprEngine::IntRange>("", -128, 128)));
                continue;
            }
            if (auto i = std::dynamic_pointer_cast<ExprEngine::IntRange>(index)) {
                if (stringLiteral && i->minValue >= 0 && i->minValue == i->maxValue) {
                    int c = 0;
                    if (i->minValue < stringLiteral->size())
                        c = stringLiteral->string[i->minValue];
                    ret.push_back(std::pair<ValuePtr,ValuePtr>(indexAndValue.index, std::make_shared<ExprEngine::IntRange>(std::to_string(c), c, c)));
                    continue;
                }
            }
            int cmin = 0, cmax = 0;
            for (char c : stringLiteral->string) {
                if (c < cmin)
                    cmin = c;
                else if (c > cmax)
                    cmax = c;
            }
            ret.push_back(std::pair<ValuePtr,ValuePtr>(indexAndValue.index, std::make_shared<ExprEngine::IntRange>("", cmin, cmax)));
            continue;
        }
        ret.push_back(std::pair<ValuePtr,ValuePtr>(indexAndValue.index, indexAndValue.value));
    }

    if (ret.size() == 1)
        ret[0].first = ExprEngine::ValuePtr();
    else if (ret.size() == 2 && !ret[0].first) {
        ret[0].first = std::make_shared<ExprEngine::BinOpResult>("!=", index, ret[1].first);
        ret[1].first = std::make_shared<ExprEngine::BinOpResult>("==", index, ret[1].first);
    } else {
        // FIXME!!
        ret.clear();
    }

    return ret;
}

std::string ExprEngine::ConditionalValue::getSymbolicExpression() const
{
    std::ostringstream ostr;
    ostr << "{";
    bool first = true;
    for (auto condvalue : values) {
        ValuePtr cond = condvalue.first;
        ValuePtr value = condvalue.second;

        if (!first)
            ostr << ",";
        first = false;
        ostr << "{"
             << (cond ? cond->getSymbolicExpression() : std::string("(null)"))
             << ","
             << value->getSymbolicExpression()
             << "}";
    }
    ostr << "}";
    return ostr.str();
}

std::string ExprEngine::ArrayValue::getSymbolicExpression() const
{
    std::ostringstream ostr;
    ostr << "size=" << (size ? size->name : std::string("(null)"));
    for (const auto indexAndValue : data) {
        ostr << ",["
             << (!indexAndValue.index ? std::string(":") : indexAndValue.index->name)
             << "]="
             << indexAndValue.value->name;
    }
    return ostr.str();
}

std::string ExprEngine::StructValue::getSymbolicExpression() const
{
    std::ostringstream ostr;
    ostr << "{";
    bool first = true;
    for (const auto& m: member) {
        const std::string &memberName = m.first;
        auto memberValue = m.second;
        if (!first)
            ostr << ",";
        first = false;
        ostr << memberName << "=" << (memberValue ? memberValue->getSymbolicExpression() : std::string("(null)"));
    }
    ostr << "}";
    return ostr.str();
}

std::string ExprEngine::PointerValue::getRange() const
{
    std::string r;
    if (data)
        r = "->" + data->getSymbolicExpression();
    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::getSymbolicExpression() const
{
    return sign + std::to_string(bits) + "(" + inputValue->getSymbolicExpression() + ")";
}

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

#define BINARY_EQ_COMPARISON(OP) \
    if (binop == #OP && !lhs.isFloat() && !rhs.isFloat()) { \
        struct ExprEngine::BinOpResult::IntOrFloatValue result; \
        result.setIntValue(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(>>)
    BINARY_EQ_COMPARISON(==)
    BINARY_EQ_COMPARISON(!=)
    BINARY_RELATIONAL_COMPARISON(>=)
    BINARY_RELATIONAL_COMPARISON(>)
    BINARY_RELATIONAL_COMPARISON(<=)
    BINARY_RELATIONAL_COMPARISON(<)

    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
{
    if (!value)
        throw std::runtime_error("Internal error: null value");

    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);
            // Sign extension
            if (valueType->sign == ValueType::Sign::SIGNED && newValue & (1ULL << (bits - 1)))
                newValue |= ~(((int128_t)1 << bits) - 1);
            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 = simplifyValue(std::make_shared<ExprEngine::BinOpResult>(binop, lhsValue, rhsValue));
    }

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

    if (lhsToken->varId() > 0) {
        data.assignValue(lhsToken, 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 (assignValue->type == ExprEngine::ValueType::StringLiteralValue)
                    arrayValue->assign(ExprEngine::ValuePtr(), assignValue);
            } 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.assignValue(lhsToken, 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);
                }
            }
        }
    } else if (Token::Match(lhsToken, ". %name%")) {
        auto structVal = executeExpression(lhsToken->astOperand1(), data);
        if (structVal && structVal->type == ExprEngine::ValueType::StructValue)
            data.assignStructMember(tok, &*std::static_pointer_cast<ExprEngine::StructValue>(structVal), lhsToken->strAt(1), assignValue);
    }
    return assignValue;
}

static ExprEngine::ValuePtr executeFunctionCall(const Token *tok, Data &data)
{
    std::vector<ExprEngine::ValuePtr> argValues;
    for (const Token *argtok : getArguments(tok)) {
        auto val = executeExpression(argtok, data);
        argValues.push_back(val);
        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);
            arrayValue->assign(ExprEngine::ValuePtr(), 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.assignValue(argtok, 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 conditionalValues = arrayValue->read(indexValue);
        for (auto value: conditionalValues)
            call(data.callbacks, tok, value.second);
        return std::make_shared<ExprEngine::ConditionalValue>(data.getNewSymbolName(), conditionalValues);
    }
    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 = simplifyValue(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() || tok->tokType() == Token::Type::eChar)
        return executeNumber(tok);

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

    return ExprEngine::ValuePtr();
}

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

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()) {
                data.assignValue(tok, tok->varId(), std::make_shared<ExprEngine::ArrayValue>(data.getNewSymbolName(), tok->variable()));
                if (Token::Match(tok, "%name% ["))
                    tok = tok->linkAt(1);
            } else if (Token::Match(tok, "%var% ;"))
                data.assignValue(tok, tok->varId(), createVariableValue(*tok->variable(), data));
        } else if (!tok->astParent() && (tok->astOperand1() || tok->astOperand2()))
            executeExpression(tok, data);

        else 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 createStructVal(const Scope *structScope, bool uninitData, Data &data)
{
    if (!structScope)
        return ExprEngine::ValuePtr();
    std::shared_ptr<ExprEngine::StructValue> structValue = std::make_shared<ExprEngine::StructValue>(data.getNewSymbolName());
    auto uninitValue = std::make_shared<ExprEngine::UninitValue>();
    for (const Variable &member : structScope->varlist) {
        if (uninitData) {
            if (member.isPointer()) {
                structValue->member[member.name()] = uninitValue;
                continue;
            }
            if (member.valueType() && member.valueType()->type >= ::ValueType::Type::CHAR) {
                structValue->member[member.name()] = uninitValue;
                continue;
            }
        }
        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, var.isLocal() && !var.isStatic(), data);
    if (valueType->smartPointerType) {
        auto structValue = createStructVal(valueType->smartPointerType->classScope, var.isLocal() && !var.isStatic(), data);
        return std::make_shared<ExprEngine::PointerValue>(data.getNewSymbolName(), structValue, true, false);
    }
    if (valueType->container && valueType->container->stdStringLike) {
        auto size = std::make_shared<ExprEngine::IntRange>(data.getNewSymbolName(), 0, ~0ULL);
        auto value = std::make_shared<ExprEngine::IntRange>(data.getNewSymbolName(), -128, 127);
        return std::make_shared<ExprEngine::ArrayValue>(data.getNewSymbolName(), size, value);
    }
    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)
        data.assignValue(functionScope->bodyStart, arg.declarationId(), createVariableValue(arg, data));

    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::function<void(const Token *, const ExprEngine::Value &)> integerOverflow = [&](const Token *tok, const ExprEngine::Value &value) {
        if (!tok->isArithmeticalOp() || !tok->valueType() || !tok->valueType()->isIntegral() || tok->valueType()->pointer > 0)
            return;

        const ExprEngine::BinOpResult *b = dynamic_cast<const ExprEngine::BinOpResult *>(&value);
        if (!b)
            return;

        ExprEngine::BinOpResult::IntOrFloatValue minValue,maxValue;
        b->getRange(&minValue, &maxValue);
        if (minValue.isFloat() || maxValue.isFloat())
            return;

        int bits = getIntBitsFromValueType(tok->valueType(), *settings);
        if (tok->valueType()->sign == ::ValueType::Sign::SIGNED) {
            int128_t v = (int128_t)1 << (bits - 1);
            if (minValue.intValue >= -v && maxValue.intValue < v)
                return;
        } else {
            int128_t v = (int128_t)1 << bits;
            if (minValue.intValue >= 0 && maxValue.intValue < v)
                return;
        }

        std::string note;
        if (tok->valueType()->sign == ::ValueType::Sign::UNSIGNED)
            note = " Note that unsigned integer overflow is defined and will wrap around.";

        std::list<const Token*> callstack{tok};
        ErrorLogger::ErrorMessage errmsg(callstack, &tokenizer->list, Severity::SeverityType::error, "verificationIntegerOverflow", "Integer overflow, " + tok->valueType()->str() + " result." + note, false);
        errorLogger->reportErr(errmsg);
    };

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