一、前言
二、Linux 平台
三、Windwos 平台
程序在执行过程中 crash 是非常严重的问题，一般都应该在测试阶段排除掉这些问题，但是总会有漏网之鱼被带到 release 阶段。
因此，程序的日志系统需要侦测这种情况，在代码崩溃的时候获取函数调用栈信息，为 debug 提供有效的信息。
这篇文章的理论知识很少，直接分享 2 段代码：在 Linux 和 Windows 这 2 个平台上，如何用 C++ 来捕获函数调用栈里的信息。
需要处理哪些异常信号
const std::map<int, std::string> Signals = {{SIGINT, "SIGINT"},{SIGABRT, "SIGABRT"},{SIGFPE, "SIGFPE"},{SIGILL, "SIGILL"},{SIGSEGV, "SIGSEGV"}// 可以添加其他信号};
注册信号处理函数
struct sigaction action;sigemptyset(&action.sa_mask);action.sa_sigaction = &sigHandler;action.sa_flags = SA_SIGINFO;for (const auto &sigPair : Signals){if (sigaction(sigPair.first, &action, NULL) < 0)fprintf(stderr, "Error: sigaction failed! \n");}
void sigHandler(int signum, siginfo_t *info, void *ctx){const size_t dump_size = 50;void *array[dump_size];int size = backtrace(array, dump_size);char **symbols = backtrace_symbols(array, size);std::ostringstream oss;for (int i = 0; i < size; ++i){char *mangleName = 0;char *offsetBegin = 0;char *offsetEnd = 0;for (char *p = symbols[i]; *p; ++p){if ('(' == *p){mangleName = p;}else if ('+' == *p){offsetBegin = p;}else if (')' == *p){offsetEnd = p;break;}}if (mangleName && offsetBegin && offsetEnd && mangleName < offsetBegin){*mangleName++ = '\0';*offsetBegin++ = '\0';*offsetEnd++ = '\0';int status;char *realName = abi::__cxa_demangle(mangleName, 0, 0, &status);if (0 == status)oss << "\tstack dump [" << i << "] " << symbols[i] << " : " << realName << "+";elseoss << "\tstack dump [" << i << "] " << symbols[i] << mangleName << "+";oss << offsetBegin << offsetEnd << std::endl;free(realName);}else{oss << "\tstack dump [" << i << "] " << symbols[i] << std::endl;}}free(symbols);oss << std::endl;std::cout << oss.str(); // 打印函数调用栈信息}
在 Windows 平台下的代码实现，参考了国外某个老兄的代码，如下：
SetUnhandledExceptionFilter(exceptionHandler);
void exceptionHandler(LPEXCEPTION_POINTERS info){CONTEXT *context = info->ContextRecord;std::shared_ptr<void> RaiiSysCleaner(nullptr, [&](void *) {SymCleanup(GetCurrentProcess());});const size_t dumpSize = 64;std::vector<uint64_t> frameVector(dumpSize);DWORD machine_type = 0;STACKFRAME64 frame = {};frame.AddrPC.Mode = AddrModeFlat;frame.AddrFrame.Mode = AddrModeFlat;frame.AddrStack.Mode = AddrModeFlat;frame.AddrPC.Offset = context->Eip;frame.AddrFrame.Offset = context->Ebp;frame.AddrStack.Offset = context->Esp;machine_type = IMAGE_FILE_MACHINE_I386;frame.AddrPC.Offset = context->Rip;frame.AddrFrame.Offset = context->Rbp;frame.AddrStack.Offset = context->Rsp;machine_type = IMAGE_FILE_MACHINE_AMD64;frame.AddrPC.Offset = context->StIIP;frame.AddrFrame.Offset = context->IntSp;frame.AddrStack.Offset = context->IntSp;machine_type = IMAGE_FILE_MACHINE_IA64;frame.AddrBStore.Offset = context.RsBSP;frame.AddrBStore.Mode = AddrModeFlat;frame.AddrPC.Offset = context->Eip;frame.AddrFrame.Offset = context->Ebp;frame.AddrStack.Offset = context->Esp;machine_type = IMAGE_FILE_MACHINE_I386;for (size_t index = 0; index < frameVector.size(); ++index){if (StackWalk64(machine_type,GetCurrentProcess(),GetCurrentThread(),&frame,context,NULL,SymFunctionTableAccess64,SymGetModuleBase64,NULL)) {frameVector[index] = frame.AddrPC.Offset;} else {break;}}std::string dump;const size_t kSize = frameVector.size();for (size_t index = 0; index < kSize && frameVector[index]; ++index) {dump += getSymbolInfo(index, frameVector);dump += "\n";}std::cout << dump;}主要是利用了 StackWalk64 这个函数，从地址转换为函数名称。
利用以上几个神器，基本上可以获取到程序崩溃时的函数调用栈信息，定位问题，有如神助！
