/*
 *     .============.
 *    //  M A K E  / \
 *   //  C++ DEV  /   \
 *  //  E A S Y  /  \/ \
 * ++ ----------.  \/\  .
 *  \\     \     \ /\  /
 *   \\     \     \   /
 *    \\     \     \ /
 *     -============'
 *
 * Copyright (c) 2018 Hevake and contributors, all rights reserved.
 *
 * This file is part of cpp-tbox (https://github.com/cpp-main/cpp-tbox)
 * Use of this source code is governed by MIT license that can be found
 * in the LICENSE file in the root of the source tree. All contributing
 * project authors may be found in the CONTRIBUTORS.md file in the root
 * of the source tree.
 */

#include "backtrace.h"

/**
 * 目前只有glibc支持execinfo.h，其它库如uclibc是没有支持。
 * 为避免编译出错，可以在外部将 HAVE_EXECINFO_H 指定为0
 */
#ifndef HAVE_EXECINFO_H
# define HAVE_EXECINFO_H 1  //! 如果是uclibc，请改成0
#endif //HAVE_EXECINFO_H

#if HAVE_EXECINFO_H
# include <execinfo.h>
# include <cxxabi.h>
# include <dlfcn.h>
# include <unistd.h>
# include <iostream>
# include <iomanip>
#endif //HAVE_EXECINFO_H

#include <sstream>
#include "defines.h"

namespace tbox {

std::string DumpBacktrace(const unsigned int max_frames)
{
    std::ostringstream oss;

#if HAVE_EXECINFO_H
    Dl_info info;

    void *callstack[max_frames];

    unsigned int number_frames = ::backtrace(callstack, max_frames);
    char **symbols = ::backtrace_symbols(callstack, number_frames);

    for (unsigned int i = 0; i < number_frames; ++i) {
        /// try to translate an address to symbolic information
        std::string func_name;

        if (dladdr(callstack[i], &info)) {
            int status = -1;
            char *demangled = abi::__cxa_demangle(info.dli_sname, NULL, 0, &status);
            if (demangled != nullptr) {
                func_name = demangled;
                free(demangled);
            } else if (info.dli_sname != nullptr) {
                func_name = info.dli_sname;
            } else {
                func_name = "null";
            }
        } else {
            func_name = (symbols != nullptr ? symbols[i] : "null");
        }

        oss << '[' << std::setw(2) << i << "]: " << func_name << " <" << callstack[i] << '>' << std::endl;
    }

    if (symbols != nullptr)
        free(symbols);

    if (number_frames >= max_frames)
        oss << "[truncated]" << std::endl;

#else
    UNUSED_VAR(max_frames);
    oss << "not support backtrace" << std::endl;
#endif //HAVE_EXECINFO_H

    return oss.str();
}

}