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**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
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** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 as published by the Free Software
** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
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/*
  Copyright 2005 Roberto Raggi <roberto@kdevelop.org>

  Permission to use, copy, modify, distribute, and sell this software and its
  documentation for any purpose is hereby granted without fee, provided that
  the above copyright notice appear in all copies and that both that
  copyright notice and this permission notice appear in supporting
  documentation.

  The above copyright notice and this permission notice shall be included in
  all copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
  KDEVELOP TEAM BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

#include "PreprocessorEnvironment.h"

#include "Macro.h"

#include <QDebug>

#include <cstring>

namespace CPlusPlus {

static unsigned hashCode(const char *str, int length)
{
    unsigned hash_value = 0;

    for (int i = 0; i < length; ++i)
        hash_value = (hash_value << 5) - hash_value + str[i];

    return hash_value;
}


Environment::Environment()
    : currentLine(0),
      hideNext(false),
      _macros(nullptr),
      _allocated_macros(0),
      _macro_count(-1),
      _hash(nullptr),
      _hash_count(401)
{
}

Environment::~Environment()
{
    if (_macros) {
        qDeleteAll(firstMacro(), lastMacro());
        free(_macros);
    }

    if (_hash)
        free(_hash);
}

unsigned Environment::macroCount() const
{
    return _macro_count + 1;
}

Macro *Environment::macroAt(unsigned index) const
{
    return _macros[index];
}

Macro *Environment::bind(const Macro &macro)
{
    Q_ASSERT(! macro.name().isEmpty());

    Macro *m = new Macro (macro);
    const QByteArray &name = m->name();
    m->_hashcode = hashCode(name.begin(), name.size());

    if (++_macro_count == _allocated_macros) {
        if (! _allocated_macros)
            _allocated_macros = 401;
        else
            _allocated_macros <<= 1;

        _macros = reinterpret_cast<Macro **>(realloc(_macros, sizeof(Macro *) * _allocated_macros));
    }

    _macros[_macro_count] = m;

    if (! _hash || _macro_count > (_hash_count >> 1)) {
        rehash();
    } else {
        const unsigned h = m->_hashcode % _hash_count;
        m->_next = _hash[h];
        _hash[h] = m;
    }

    return m;
}

void Environment::addMacros(const QList<Macro> &macros)
{
    foreach (const Macro &macro, macros) {
        bind(macro);
    }
}

Macro *Environment::remove(const ByteArrayRef &name)
{
    Macro macro;
    macro.setName(name.toByteArray());
    macro.setHidden(true);
    macro.setFileName(currentFile);
    macro.setLine(currentLine);
    return bind(macro);
}

void Environment::reset()
{
    if (_macros) {
        qDeleteAll(firstMacro(), lastMacro());
        free(_macros);
    }

    if (_hash)
        free(_hash);

    _macros = nullptr;
    _allocated_macros = 0;
    _macro_count = -1;
    _hash = nullptr;
    _hash_count = 401;
}

bool Environment::isBuiltinMacro(const ByteArrayRef &s)
{
    if (s.length() != 8)
        return false;

    if (s[0] == '_') {
        if (s[1] == '_') {
            if (s[2] == 'D') {
                if (s[3] == 'A') {
                    if (s[4] == 'T') {
                        if (s[5] == 'E') {
                            if (s[6] == '_') {
                                if (s[7] == '_') {
                                    return true;
                                }
                            }
                        }
                    }
                }
            } else if (s[2] == 'F') {
                if (s[3] == 'I') {
                    if (s[4] == 'L') {
                        if (s[5] == 'E') {
                            if (s[6] == '_') {
                                if (s[7] == '_') {
                                    return true;
                                }
                            }
                        }
                    }
                }
            } else if (s[2] == 'L') {
                if (s[3] == 'I') {
                    if (s[4] == 'N') {
                        if (s[5] == 'E') {
                            if (s[6] == '_') {
                                if (s[7] == '_') {
                                    return true;
                                }
                            }
                        }
                    }
                }
            } else if (s[2] == 'T') {
                if (s[3] == 'I') {
                    if (s[4] == 'M') {
                        if (s[5] == 'E') {
                            if (s[6] == '_') {
                                if (s[7] == '_') {
                                    return true;
                                }
                            }
                        }
                    }
                }
            }
        }
    }
    return false;
}

Environment::iterator Environment::firstMacro() const
{ return _macros; }

Environment::iterator Environment::lastMacro() const
{ return _macros + _macro_count + 1; }

Macro *Environment::resolve(const ByteArrayRef &name) const
{
    if (! _macros)
        return nullptr;

    Macro *it = _hash[hashCode(name.start(), name.size()) % _hash_count];
    for (; it; it = it->_next) {
        if (it->name() != name)
            continue;
        else if (it->isHidden())
            return nullptr;
        else break;
    }
    return it;
}

void Environment::rehash()
{
    if (_hash) {
        free(_hash);
        _hash_count <<= 1;
    }

    _hash = reinterpret_cast<Macro **>(calloc(_hash_count, sizeof(Macro *)));

    for (iterator it = firstMacro(); it != lastMacro(); ++it) {
        Macro *m = *it;
        const unsigned h = m->_hashcode % _hash_count;
        m->_next = _hash[h];
        _hash[h] = m;
    }
}

void Environment::dump() const
{
    for (iterator it = firstMacro(); it != lastMacro(); ++it) {
        Macro *m = *it;
        qDebug() << m->decoratedName();
    }
}

} // namespace CPlusPlus