Files
qt-creator/src/libs/cplusplus/PPToken.h
Tim Blechmann f4a64fd8c8 cplusplus: PPToken - introduce move constructor
profiling qt-creator on my codebase i saw quite a few instances where
reference counting of `QByteArray` showed up in
`Preprocessor::handleFunctionLikeMacro` (hundreds of milliseconds of CPU
time when profiling for a few seconds). using move semantics we can
avoid this source of reference counting.

Change-Id: I19a88a0501064f53d8095f7377bf901e462d25a0
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>
2021-04-27 10:56:52 +00:00

153 lines
4.3 KiB
C++

/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of Qt Creator.
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** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
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#pragma once
#include <cplusplus/CPlusPlus.h>
#include <cplusplus/Token.h>
#include <QByteArray>
namespace CPlusPlus {
class CPLUSPLUS_EXPORT ByteArrayRef
{
public:
ByteArrayRef()
: m_start("")
, m_length(0)
{}
ByteArrayRef(const QByteArray *ref)
: m_start(ref->constData())
, m_length(ref->length())
{}
ByteArrayRef(const char *start, int length)
: m_start(start)
, m_length(length)
{}
ByteArrayRef(const QByteArray *ref, int offset, int length)
: m_start(ref->constData() + offset)
, m_length(length)
{}
inline const char *start() const
{ return m_start; }
inline int length() const
{ return m_length; }
inline int size() const
{ return length(); }
inline char at(int pos) const
{ return pos >= 0 && pos < m_length ? m_start[pos] : '\0'; }
inline char operator[](int pos) const
{ return at(pos); }
QByteArray toByteArray() const
{ return QByteArray(m_start, m_length); }
bool operator==(const QByteArray &other) const
{ return m_length == other.length() && !qstrncmp(m_start, other.constData(), m_length); }
bool operator!=(const QByteArray &other) const
{ return !this->operator==(other); }
bool operator==(const char *other) const
{ return m_length == (int) qstrlen(other) && !qstrncmp(m_start, other, m_length); }
bool operator!=(const char *other) const
{ return !this->operator==(other); }
bool startsWith(const char *ch) const;
int count(char c) const;
private:
const char *m_start;
const int m_length;
};
inline bool operator==(const QByteArray &other, const ByteArrayRef &ref)
{ return ref == other; }
inline bool operator!=(const QByteArray &other, const ByteArrayRef &ref)
{ return ref != other; }
namespace Internal {
class CPLUSPLUS_EXPORT PPToken: public Token
{
public:
PPToken() {}
PPToken(const QByteArray &src)
: m_src(src)
{}
PPToken(QByteArray &&src)
: m_src(std::move(src))
{}
void setSource(const QByteArray &src)
{ m_src = src; }
const QByteArray &source() const
{ return m_src; }
bool hasSource() const
{ return !m_src.isEmpty(); }
void squeezeSource();
const char *bufferStart() const
{ return m_src.constData(); }
const char *tokenStart() const
{ return bufferStart() + byteOffset; }
ByteArrayRef asByteArrayRef() const
{ return ByteArrayRef(&m_src, byteOffset, bytes()); }
unsigned originalOffset() const
{ return m_originalOffset != -1 ? m_originalOffset : byteOffset; }
private:
QByteArray m_src;
// TODO: We may or may not be able to get rid of this member. In order to find out,
// all code calling this class' accessors (including the parent class'
// bytes* and utf16* functions) has to be looked at. Essentially, it boils
// down to whether there are contexts where an object of this class is used
// and the original "global" string is no longer available. (If not, then the
// m_src member would also not be needed.)
int m_originalOffset = -1;
};
} // namespace Internal
} // namespace CPlusPlus