/*

Copyright (c) 2007-2020, Arvid Norberg

Copyright (c) 2008, Andrew Resch

Copyright (c) 2016-2017, Alden Torres

Copyright (c) 2017, Steven Siloti

Copyright (c) 2020, Tiger Wang

All rights reserved.

Redistribution and use in source and binary forms, with or without

modification, are permitted provided that the following conditions

are met:

    * Redistributions of source code must retain the above copyright

      notice, this list of conditions and the following disclaimer.

    * 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.

    * Neither the name of the author 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 OWNER 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.

*/

#include "libtorrent/config.hpp"

#include "libtorrent/assert.hpp"

#include "libtorrent/aux_/disable_warnings_push.hpp"

#ifdef TORRENT_PRODUCTION_ASSERTS

#include <atomic>

#endif

#if TORRENT_USE_ASSERTS \

  || defined TORRENT_ASIO_DEBUGGING \

  || defined TORRENT_PROFILE_CALLS \

  || defined TORRENT_DEBUG_BUFFERS

#ifdef __APPLE__

#include <AvailabilityMacros.h>

#endif

#include <string>

#include <cstring>

#include <cstdlib>

#include <cstdarg>

#include <cstdio> // for snprintf

#include <cinttypes> // for PRId64 et.al.

#include <array>

#include "libtorrent/aux_/disable_warnings_pop.hpp"

// uClibc++ doesn't have cxxabi.h

#if defined __GNUC__ && __GNUC__ >= 3 \

  && !defined __UCLIBCXX_MAJOR__

#include <cxxabi.h>

namespace libtorrent {

std::string demangle(char const* name)

{

// in case this string comes

  // this is needed on linux

  char const* start = std::strchr(name, '(');

  if (start != nullptr)

  {

    ++start;

  }

  else

  {

    // this is needed on macos x

    start = strstr(name, "0x");

    if (start != nullptr)

    {

      start = std::strchr(start, ' ');

      if (start != nullptr) ++start;

      else start = name;

    }

    else start = name;

  }

  char const* end = std::strchr(start, '+');

  if (end) while (*(end-1) == ' ') --end;

  std::string in;

  if (end == nullptr) in.assign(start);

  else in.assign(start, end);

  size_t len;

  int status;

  char* unmangled = ::abi::__cxa_demangle(in.c_str(), nullptr, &len, &status);

  if (unmangled == nullptr) return in;

  std::string ret(unmangled);

  ::free(unmangled);

  return ret;

}

}

#elif defined _WIN32 && !defined TORRENT_WINRT

#include "libtorrent/aux_/windows.hpp"

#include <DbgHelp.h>

namespace libtorrent {

std::string demangle(char const* name)

{

  char demangled_name[256];

  if (UnDecorateSymbolName(name, demangled_name, sizeof(demangled_name), UNDNAME_NO_THROW_SIGNATURES) == 0)

    demangled_name[0] = 0;

  return demangled_name;

}

}

#else

namespace libtorrent {

std::string demangle(char const* name) { return name; }

}

#endif

#include <cstdlib>

#include <cstdio>

#include <csignal>

#include "libtorrent/version.hpp"

#if TORRENT_USE_EXECINFO

#include <execinfo.h>

namespace libtorrent {

TORRENT_EXPORT void print_backtrace(char* out, int len, int max_depth, void*)

{

  void* stack[50];

  int size = ::backtrace(stack, 50);

  char** symbols = ::backtrace_symbols(stack, size);

  for (int i = 1; i < size && len > 0; ++i)

  {

    int ret = std::snprintf(out, std::size_t(len), "%d: %s\n", i, demangle(symbols[i]).c_str());

    out += ret;

    len -= ret;

    if (i - 1 == max_depth && max_depth > 0) break;

  }

  ::free(symbols);

}

}

#elif defined _WIN32 && !defined TORRENT_WINRT

#include "libtorrent/aux_/windows.hpp"

#include "libtorrent/utf8.hpp"

#include <mutex>

#include <WinBase.h>

#include <DbgHelp.h>

namespace libtorrent {

TORRENT_EXPORT void print_backtrace(char* out, int len, int max_depth

  , void* ctx)

{

  // all calls to DbgHlp.dll are thread-unsafe. i.e. they all need to be

  // synchronized and not called concurrently. This mutex serializes access

  static std::mutex dbghlp_mutex;

  std::lock_guard<std::mutex> l(dbghlp_mutex);

  CONTEXT context_record;

  if (ctx)

  {

    context_record = *static_cast<CONTEXT*>(ctx);

  }

  else

  {

    // use the current thread's context

    RtlCaptureContext(&context_record);

  }

  int size = 0;

  std::array<void*, 50> stack;

  STACKFRAME64 stack_frame = {};

#if defined(_M_IX86)

  int const machine_type = IMAGE_FILE_MACHINE_I386;

  stack_frame.AddrPC.Offset = context_record.Eip;

  stack_frame.AddrFrame.Offset = context_record.Ebp;

  stack_frame.AddrStack.Offset = context_record.Esp;

#elif defined(_M_X64)

  int const machine_type = IMAGE_FILE_MACHINE_AMD64;

  stack_frame.AddrPC.Offset = context_record.Rip;

  stack_frame.AddrFrame.Offset = context_record.Rbp;

  stack_frame.AddrStack.Offset = context_record.Rsp;

#elif defined(_M_ARM64)

  int const machine_type = IMAGE_FILE_MACHINE_ARM64;

  stack_frame.AddrPC.Offset = context_record.Pc;

  stack_frame.AddrFrame.Offset = context_record.Fp;

  stack_frame.AddrStack.Offset = context_record.Sp;

#endif

  stack_frame.AddrPC.Mode = AddrModeFlat;

  stack_frame.AddrFrame.Mode = AddrModeFlat;

  stack_frame.AddrStack.Mode = AddrModeFlat;

  while (StackWalk64(machine_type,

    GetCurrentProcess(),

    GetCurrentThread(),

    &stack_frame,

    &context_record,

    nullptr,

    &SymFunctionTableAccess64,

    &SymGetModuleBase64,

    nullptr) && size < int(stack.size()))

  {

    stack[size++] = reinterpret_cast<void*>(stack_frame.AddrPC.Offset);

  }

  struct symbol_bundle : SYMBOL_INFO

  {

    wchar_t name[MAX_SYM_NAME];

  };

  HANDLE p = GetCurrentProcess();

  static bool sym_initialized = false;

  if (!sym_initialized)

  {

    sym_initialized = true;

    SymInitialize(p, nullptr, true);

  }

  SymRefreshModuleList(p);

  for (int i = 0; i < size && len > 0; ++i)

  {

    DWORD_PTR frame_ptr = reinterpret_cast<DWORD_PTR>(stack[i]);

    DWORD64 displacement = 0;

    symbol_bundle symbol;

    symbol.MaxNameLen = MAX_SYM_NAME;

    symbol.SizeOfStruct = sizeof(SYMBOL_INFO);

    BOOL const has_symbol = SymFromAddr(p, frame_ptr, &displacement, &symbol);

    DWORD line_displacement = 0;

    IMAGEHLP_LINE64 line = {};

    line.SizeOfStruct = sizeof(IMAGEHLP_LINE64);

    BOOL const has_line = SymGetLineFromAddr64(GetCurrentProcess(), frame_ptr,

      &line_displacement, &line);

    int ret = std::snprintf(out, len, "%2d: %p", i, stack[i]);

    out += ret; len -= ret; if (len <= 0) break;

    if (has_symbol)

    {

      ret = std::snprintf(out, len, " %s +%-4" PRId64

        , demangle(symbol.Name).c_str(), displacement);

      out += ret; len -= ret; if (len <= 0) break;

    }

    if (has_line)

    {

      ret = std::snprintf(out, len, " %s:%d"

        , line.FileName, int(line.LineNumber));

      out += ret; len -= ret; if (len <= 0) break;

    }

    ret = std::snprintf(out, len, "\n");

    out += ret;

    len -= ret;

    if (i == max_depth && max_depth > 0) break;

  }

}

}

#else

namespace libtorrent {

TORRENT_EXPORT void print_backtrace(char* out, int len, int /*max_depth*/, void* /* ctx */)

{

  out[0] = 0;

  std::strncat(out, "<not supported>", std::size_t(len));

}

}

#endif

#endif

#if (TORRENT_USE_ASSERTS || defined TORRENT_ASIO_DEBUGGING) && \

  defined TORRENT_PRODUCTION_ASSERTS

char const* libtorrent_assert_log = "asserts.log";

namespace {

// the number of asserts we've printed to the log

std::atomic<int> assert_counter(0);

}

#endif

namespace libtorrent {

#if TORRENT_USE_ASSERTS || defined TORRENT_ASIO_DEBUGGING

TORRENT_FORMAT(1,2)

TORRENT_EXPORT void assert_print(char const* fmt, ...)

{

#ifdef TORRENT_PRODUCTION_ASSERTS

  if (assert_counter > 500) return;

  FILE* out = fopen(libtorrent_assert_log, "a+");

  if (out == nullptr) out = stderr;

#else

  FILE* out = stderr;

#endif

  va_list va;

  va_start(va, fmt);

  std::vfprintf(out, fmt, va);

  va_end(va);

#ifdef TORRENT_PRODUCTION_ASSERTS

  if (out != stderr) fclose(out);

#endif

}

// we deliberately don't want asserts to be marked as no-return, since that

// would trigger warnings in debug builds of any code coming after the assert

#ifdef __clang__

#pragma clang diagnostic push

#pragma clang diagnostic ignored "-Wmissing-noreturn"

#endif

TORRENT_EXPORT void assert_fail(char const* expr, int line

  , char const* file, char const* function, char const* value, int kind)

{

#ifdef TORRENT_PRODUCTION_ASSERTS

  // no need to flood the assert log with infinite number of asserts

  if (assert_counter.fetch_add(1) + 1 > 500) return;

#endif

  char stack[8192];

  stack[0] = '\0';

  print_backtrace(stack, sizeof(stack), 0);

  char const* message = "assertion failed. Please file a bugreport at "

    "https://github.com/arvidn/libtorrent/issues\n"

    "Please include the following information:\n\n"

    "version: " LIBTORRENT_VERSION "-" LIBTORRENT_REVISION "\n";

  switch (kind)

  {

    case 1:

      message = "A precondition of a libtorrent function has been violated.\n"

        "This indicates a bug in the client application using libtorrent\n";

  }

  assert_print("%s\n"

#ifdef TORRENT_PRODUCTION_ASSERTS

    "#: %d\n"

#endif

    "file: '%s'\n"

    "line: %d\n"

    "function: %s\n"

    "expression: %s\n"

    "%s%s\n"

    "stack:\n"

    "%s\n"

    , message

#ifdef TORRENT_PRODUCTION_ASSERTS

    , assert_counter.load()

#endif

    , file, line, function, expr

    , value ? value : "", value ? "\n" : ""

    , stack);

  // if production asserts are defined, don't abort, just print the error

#ifndef TORRENT_PRODUCTION_ASSERTS

#ifdef TORRENT_WINDOWS

  // SIGABRT doesn't trigger a break with msvc

  __debugbreak();

#else

  // send SIGABRT to the current process

  // to break into the debugger

  std::raise(SIGABRT);

#endif

  std::abort();

#endif

}

#ifdef __clang__

#pragma clang diagnostic pop

#endif

#elif !TORRENT_USE_ASSERTS

// these are just here to make it possible for a client that built with debug

// enable to be able to link against a release build (just possible, not

// necessarily supported)

TORRENT_FORMAT(1,2)

TORRENT_EXPORT void assert_print(char const*, ...) {}

TORRENT_EXPORT void assert_fail(char const*, int, char const*

  , char const*, char const*, int) {}

#endif

} // libtorrent namespace