// Copyright (c) 2016-2019, The Monero Project
// Copyright (c)      2018, The Loki Project
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification, are
// permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this list of
//    conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice, this list
//    of conditions and the following disclaimer in the documentation and/or other
//    materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its contributors may be
//    used to endorse or promote products derived from this software without specific
//    prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#if !defined __GNUC__ || defined __MINGW32__ || defined __MINGW64__ || defined __ANDROID__
#define USE_UNWIND
#else
#define ELPP_FEATURE_CRASH_LOG 1
#endif
#include "easylogging++/easylogging++.h"

#include <stdexcept>
#ifdef USE_UNWIND
#define UNW_LOCAL_ONLY
#include <libunwind.h>
#include <cxxabi.h>
#endif
#ifndef STATICLIB
#include <dlfcn.h>
#endif
#include <boost/algorithm/string.hpp>
#include "common/stack_trace.h"
#include "misc_log_ex.h"

#undef LOKI_DEFAULT_LOG_CATEGORY
#define LOKI_DEFAULT_LOG_CATEGORY "stacktrace"

#define ST_LOG(x) \
  do { \
    auto elpp = ELPP; \
    if (elpp) { \
      CINFO(el::base::Writer,el::base::DispatchAction::FileOnlyLog,LOKI_DEFAULT_LOG_CATEGORY) << x; \
    } \
    else { \
      std::cout << x << std::endl; \
    } \
  } while(0)

// from https://stackoverflow.com/questions/11665829/how-can-i-print-stack-trace-for-caught-exceptions-in-c-code-injection-in-c

// The decl of __cxa_throw in /usr/include/.../cxxabi.h uses
// 'std::type_info *', but GCC's built-in protype uses 'void *'.
#ifdef __clang__
#define CXA_THROW_INFO_T std::type_info
#else // !__clang__
#define CXA_THROW_INFO_T void
#endif // !__clang__

#ifdef STATICLIB
#define CXA_THROW __wrap___cxa_throw
extern "C"
__attribute__((noreturn))
void __real___cxa_throw(void *ex, CXA_THROW_INFO_T *info, void (*dest)(void*));
#else // !STATICLIB
#define CXA_THROW __cxa_throw
extern "C"
typedef
#ifdef __clang__ // only clang, not GCC, lets apply the attr in typedef
__attribute__((noreturn))
#endif // __clang__
void (cxa_throw_t)(void *ex, CXA_THROW_INFO_T *info, void (*dest)(void*));
#endif // !STATICLIB

extern "C"
__attribute__((noreturn))
void CXA_THROW(void *ex, CXA_THROW_INFO_T *info, void (*dest)(void*))
{

  int status;
  char *dsym = abi::__cxa_demangle(((const std::type_info*)info)->name(), NULL, NULL, &status);
  tools::log_stack_trace((std::string("Exception: ")+((!status && dsym) ? dsym : (const char*)info)).c_str());
  free(dsym);

#ifndef STATICLIB
#ifndef __clang__ // for GCC the attr can't be applied in typedef like for clang
  __attribute__((noreturn))
#endif // !__clang__
   cxa_throw_t *__real___cxa_throw = (cxa_throw_t*)dlsym(RTLD_NEXT, "__cxa_throw");
#endif // !STATICLIB
  __real___cxa_throw(ex, info, dest);
}

namespace
{
  std::string stack_trace_log;
}

namespace tools
{

void set_stack_trace_log(const std::string &log)
{
  stack_trace_log = log;
}

void log_stack_trace(const char *msg)
{
#ifdef USE_UNWIND
  unw_context_t ctx;
  unw_cursor_t cur;
  unw_word_t ip, off;
  unsigned level;
  char sym[512], *dsym;
  int status;
  const char *log = stack_trace_log.empty() ? NULL : stack_trace_log.c_str();
#endif

  if (msg)
    ST_LOG(msg);
  ST_LOG("Unwound call stack:");

#ifdef USE_UNWIND
  if (unw_getcontext(&ctx) < 0) {
    ST_LOG("Failed to create unwind context");
    return;
  }
  if (unw_init_local(&cur, &ctx) < 0) {
    ST_LOG("Failed to find the first unwind frame");
    return;
  }
  for (level = 1; level < 999; ++level) { // 999 for safety
    int ret = unw_step(&cur);
    if (ret < 0) {
      ST_LOG("Failed to find the next frame");
      return;
    }
    if (ret == 0)
      break;
    if (unw_get_reg(&cur, UNW_REG_IP, &ip) < 0) {
      ST_LOG("  " << std::setw(4) << level);
      continue;
    }
    if (unw_get_proc_name(&cur, sym, sizeof(sym), &off) < 0) {
      ST_LOG("  " << std::setw(4) << level << std::setbase(16) << std::setw(20) << "0x" << ip);
      continue;
    }
    dsym = abi::__cxa_demangle(sym, NULL, NULL, &status);
    ST_LOG("  " << std::setw(4) << level << std::setbase(16) << std::setw(20) << "0x" << ip << " " << (!status && dsym ? dsym : sym) << " + " << "0x" << off);
    free(dsym);
  }
#else
  std::stringstream ss;
  ss << el::base::debug::StackTrace();
  std::vector<std::string> lines;
  std::string s = ss.str();
  boost::split(lines, s, boost::is_any_of("\n"));
  for (const auto &line: lines)
    ST_LOG(line);
#endif
}

}  // namespace tools
