/*
  backtrace_unix.cpp

  This file is part of GammaRay, the Qt application inspection and
  manipulation tool.

  Copyright (C) 2010-2016 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com
  Author: Milian Wolff <milian.wolff@kdab.com>

  Licensees holding valid commercial KDAB GammaRay licenses may use this file in
  accordance with GammaRay Commercial License Agreement provided with the Software.

  Contact info@kdab.com if any conditions of this licensing are not clear to you.

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.

  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
*/
// krazy:excludeall=cpp since lots of low-level stuff in here

#include <config-gammaray.h>
#include "backtrace.h"

#include <QString>
#include <stdlib.h>

#ifdef HAVE_BACKTRACE
#include <execinfo.h>

#ifdef HAVE_CXA_DEMANGLE
#include <cxxabi.h>
#endif

static QString maybeDemangleName(char *name)
{
#ifdef HAVE_CXA_DEMANGLE
    auto mangledNameStart = strstr(name, "(_Z");
    if (mangledNameStart) {
        ++mangledNameStart;
        const auto mangledNameEnd = strstr(mangledNameStart, "+");
        if (mangledNameEnd) {
            int status;
            *mangledNameEnd = 0;
            auto demangled = abi::__cxa_demangle(mangledNameStart, 0, 0, &status);
            *mangledNameEnd = '+';
            if (status == 0 && demangled) {
                QString ret = QString::fromLatin1(name, mangledNameStart - name)
                              +QString::fromLatin1(demangled)
                              +QString::fromLatin1(mangledNameEnd);
                free(demangled);
                return ret;
            }
        }
    }
#endif
    return QString::fromLatin1(name);
}

#endif

Backtrace getBacktrace(int levels)
{
    QStringList s;
#ifdef HAVE_BACKTRACE
    void *trace[256];
    int n = backtrace(trace, 256);
    if (!n)
        return s;
    char **strings = backtrace_symbols(trace, n);

    if (levels != -1)
        n = qMin(n, levels);

    s.reserve(n);
    for (int i = 0; i < n; ++i)
        s << maybeDemangleName(strings[i]);

    if (strings)
        free(strings);

#else
    Q_UNUSED(levels);
#endif
    return s;
}
