libcruft-util/backtrace_execinfo.cpp

/*
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * Copyright 2010-2014 Danny Robson <danny@nerdcruft.net>
 */


#include "backtrace.hpp"

#include "debug.hpp"
#include "types/casts.hpp"

#include <cstdlib>
#include <execinfo.h>
#include <algorithm>
#include <memory>


using namespace std;


//-----------------------------------------------------------------------------
debug::backtrace::backtrace (void):
    m_frames (DEFAULT_DEPTH) {

    size_t last;
    size_t size = m_frames.size ();

    while ((last = ::backtrace (&m_frames[0], m_frames.size ())) == size)
        m_frames.resize (size = m_frames.size () * 2);

    CHECK_GT (last, 0);
    m_frames.resize (last);
}


//-----------------------------------------------------------------------------
ostream&
debug::operator <<(ostream &os, const debug::backtrace &rhs) {
    const auto frames = rhs.frames ();

    // We don't use the array form of unique_ptr as clang fails on ambigious constructors
    typedef unique_ptr<char *, decltype(&std::free)> unique_str;
    unique_str names (backtrace_symbols (frames.data (), frames.size ()), ::free);

    for (unsigned int i = 0; i < frames.size (); ++i)
        os << frames[i] << "\t" << names.get()[i] << "\n";

    return os;
}