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#include "qv4function_p.h"
#include "qv4managed_p.h"
#include "qv4string_p.h"
#include "qv4value_p.h"
#include "qv4engine_p.h"
#include "qv4lookup_p.h"
#include "qv4unwindhelper_p.h"

QT_BEGIN_NAMESPACE

using namespace QV4;

Function::Function(ExecutionEngine *engine, CompiledData::CompilationUnit *unit, const CompiledData::Function *function,
                   ReturnedValue (*codePtr)(ExecutionContext *, const uchar *), quint32 _codeSize)
        : compiledFunction(function)
        , compilationUnit(unit)
        , codePtr(codePtr)
        , codeData(0)
        , codeSize(_codeSize)
{
    name = compilationUnit->runtimeStrings[compiledFunction->nameIndex].asString();

    formals.resize(compiledFunction->nFormals);
    formals.fill(0);
    const quint32 *formalsIndices = compiledFunction->formalsTable();
    for (int i = 0; i < compiledFunction->nFormals; ++i)
        formals[i] = engine->newString(unit->data->stringAt(formalsIndices[i]));


    locals.resize(compiledFunction->nLocals);
    locals.fill(0);
    const quint32 *localsIndices = compiledFunction->localsTable();
    for (int i = 0; i < compiledFunction->nLocals; ++i)
        locals[i] = engine->newString(unit->data->stringAt(localsIndices[i]));
}

Function::~Function()
{
}


void Function::mark()
{
    if (name.asManaged())
        name.asManaged()->mark();
    for (int i = 0; i < formals.size(); ++i)
        formals.at(i)->mark();
    for (int i = 0; i < locals.size(); ++i)
        locals.at(i)->mark();
}

namespace QV4 {
struct LineNumberMappingHelper
{
    const quint32 *table;
    int lowerBound(int begin, int end, qptrdiff offset) {
        int middle;
        int n = int(end - begin);
        int half;

        while (n > 0) {
            half = n >> 1;
            middle = begin + half;
            if (table[middle * 2] < offset) {
                begin = middle + 1;
                n -= half + 1;
            } else {
                n = half;
            }
        }
        return begin;
    }
};

}

int Function::lineNumberForProgramCounter(qptrdiff offset) const
{
    LineNumberMappingHelper helper;
    helper.table = compiledFunction->lineNumberMapping();
    const uint count = compiledFunction->nLineNumberMappingEntries;

    int pos = helper.lowerBound(0, count, offset);
    if (pos != 0 && count > 0)
        --pos;
    if (pos == count)
        return -1;
    return helper.table[pos * 2 + 1];
}

QT_END_NAMESPACE