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#include <private/qv4bytecodegenerator_p.h>
#include <private/qv4jsir_p.h>
#include <private/qqmljsastfwd_p.h>

QT_USE_NAMESPACE
using namespace QV4;
using namespace Moth;

void BytecodeGenerator::setLocation(const QQmlJS::AST::SourceLocation &loc)
{
    if (static_cast<int>(loc.startLine) == currentLine)
        return;
    currentLine = static_cast<int>(loc.startLine);
    Instruction::Line line;
    line.lineNumber = currentLine;
//    addInstruction(line);
}

unsigned BytecodeGenerator::newTemp()
{
    int t = function->currentTemp++;
    if (function->tempCount < function->currentTemp)
        function->tempCount = function->currentTemp;
    return t;
}

unsigned BytecodeGenerator::newTempArray(int n)
{
    int t = function->currentTemp;
    function->currentTemp += n;
    if (function->tempCount < function->currentTemp)
        function->tempCount = function->currentTemp;
    return t;
}

QByteArray BytecodeGenerator::finalize()
{
    QByteArray code;

    Instruction::InitStackFrame init;
    init.instructionType = Instr::InitStackFrame;
    init.value = quint32(function->tempCount);
    code.append(reinterpret_cast<const char *>(&init), InstrMeta<Instr::InitStackFrame>::Size);

    // content
    QVector<int> instructionOffsets;
    instructionOffsets.reserve(instructions.size());
    for (const auto &i : qAsConst(instructions)) {
        instructionOffsets.append(code.size());
        code.append(reinterpret_cast<const char *>(&i.instr), i.size);
    }

    // resolve jumps
//    qDebug() << "resolving jumps";
    for (const auto &j : jumps) {
        Q_ASSERT(j.linkedLabel != -1);
        int linkedInstruction = labels.at(j.linkedLabel);
        Q_ASSERT(linkedInstruction != -1);
        int offset = instructionOffsets.at(j.instructionIndex) + j.offset;
//        qDebug() << "offset data is at" << offset;
        char *c = code.data() + offset;
        ptrdiff_t linkedInstructionOffset = instructionOffsets.at(linkedInstruction) - offset;
//        qDebug() << "linked instruction" << linkedInstruction << "at " << instructionOffsets.at(linkedInstruction);
        memcpy(c, &linkedInstructionOffset, sizeof(ptrdiff_t));
    }

    return code;
}