Revision control
Copy as Markdown
// Copyright (C) 2019 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
// Qt-Security score:significant
#ifndef QV4UTIL_H
#define QV4UTIL_H
//
// W A R N I N G
// -------------
//
// This file is not part of the Qt API. It exists purely as an
// implementation detail. This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//
#include <QtCore/QBitArray>
#include <QtCore/private/qglobal_p.h>
#include <algorithm>
#include <vector>
QT_BEGIN_NAMESPACE
namespace QV4 {
#if !defined(BROKEN_STD_VECTOR_BOOL_OR_BROKEN_STD_FIND)
// Sanity:
class BitVector
{
std::vector<bool> bits;
public:
BitVector(int size = 0, bool value = false)
: bits(size, value)
{}
void clear()
{ bits = std::vector<bool>(bits.size(), false); }
void reserve(int size)
{ bits.reserve(size); }
int size() const
{
Q_ASSERT(bits.size() < INT_MAX);
return static_cast<int>(bits.size());
}
void resize(int newSize)
{ bits.resize(newSize); }
void resize(int newSize, bool newValue)
{ bits.resize(newSize, newValue); }
void assign(int newSize, bool value)
{ bits.assign(newSize, value); }
int findNext(int start, bool value, bool wrapAround) const
{
// The ++operator of std::vector<bool>::iterator in libc++ has a bug when using it on an
// iterator pointing to the last element. It will not be set to ::end(), but beyond
// that. (It will be set to the first multiple of the native word size that is bigger
// than size().)
//
//
// The work-around is to calculate the distance, and compare it to the size() to see if it's
// beyond the end, or take the minimum of the distance and the size.
size_t pos = std::distance(bits.begin(),
std::find(bits.begin() + start, bits.end(), value));
if (wrapAround && pos >= static_cast<size_t>(size()))
pos = std::distance(bits.begin(),
std::find(bits.begin(), bits.begin() + start, value));
pos = qMin(pos, static_cast<size_t>(size()));
Q_ASSERT(pos <= static_cast<size_t>(size()));
Q_ASSERT(pos < INT_MAX);
return static_cast<int>(pos);
}
bool at(int idx) const
{ return bits.at(idx); }
void setBit(int idx)
{ bits[idx] = true; }
void clearBit(int idx)
{ bits[idx] = false; }
};
#else // Insanity:
class BitVector
{
QBitArray bits;
public:
BitVector(int size = 0, bool value = false)
: bits(size, value)
{}
void clear()
{ bits = QBitArray(bits.size(), false); }
void reserve(int size)
{ Q_UNUSED(size); }
int size() const
{ return bits.size(); }
void resize(int newSize)
{ bits.resize(newSize); }
void resize(int newSize, bool newValue)
{
int oldSize = bits.size();
bits.resize(newSize);
bits.fill(newValue, oldSize, bits.size());
}
void assign(int newSize, bool value)
{
bits.resize(newSize);
bits.fill(value);
}
int findNext(int start, bool value, bool wrapAround) const
{
for (int i = start, ei = size(); i < ei; ++i) {
if (at(i) == value)
return i;
}
if (wrapAround) {
for (int i = 0, ei = start; i < ei; ++i) {
if (at(i) == value)
return i;
}
}
return size();
}
bool at(int idx) const
{ return bits.at(idx); }
void setBit(int idx)
{ bits[idx] = true; }
void clearBit(int idx)
{ bits[idx] = false; }
};
#endif
}
QT_END_NAMESPACE
#endif // QV4UTIL_H