程序崩潰時(shí)，如何獲取函數(shù)調(diào)用棧信息

• 一、前言

• 二、Linux 平臺(tái)

• 三、Windwos 平臺(tái)

一、前言

程序在執(zhí)行過(guò)程中 crash 是非常嚴(yán)重的問(wèn)題，一般都應(yīng)該在測(cè)試階段排除掉這些問(wèn)題，但是總會(huì)有漏網(wǎng)之魚(yú)被帶到 release 階段。

因此，程序的日志系統(tǒng)需要偵測(cè)這種情況，在代碼崩潰的時(shí)候獲取函數(shù)調(diào)用棧信息，為 debug 提供有效的信息。

這篇文章的理論知識(shí)很少，直接分享 2 段代碼：在 Linux 和 Windows 這 2 個(gè)平臺(tái)上，如何用 C++ 來(lái)捕獲函數(shù)調(diào)用棧里的信息。

二、Linux 平臺(tái)

1. 注冊(cè)異常信號(hào)的處理函數(shù)

需要處理哪些異常信號(hào)

#include <execinfo.h>#include <cxxabi.h>#include <signal.h>
const std::map<int, std::string> Signals = {    {SIGINT, "SIGINT"},        {SIGABRT, "SIGABRT"},     {SIGFPE, "SIGFPE"},       {SIGILL, "SIGILL"},      {SIGSEGV, "SIGSEGV"}    // 可以添加其他信號(hào)};

注冊(cè)信號(hào)處理函數(shù)

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"); }

2. 捕獲異常，獲取函數(shù)調(diào)用棧信息

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 << "+";            else                oss << "\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(); // 打印函數(shù)調(diào)用棧信息}

三、Windwos 平臺(tái)

在 Windows 平臺(tái)下的代碼實(shí)現(xiàn)，參考了國(guó)外某個(gè)老兄的代碼，如下：

1. 設(shè)置異常處理函數(shù)

#include <windows.h>#include <dbghelp.h>
SetUnhandledExceptionFilter(exceptionHandler);

2. 捕獲異常，獲取函數(shù)調(diào)用棧信息

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;
#ifdef _M_IX86  frame.AddrPC.Offset = context->Eip;  frame.AddrFrame.Offset = context->Ebp;  frame.AddrStack.Offset = context->Esp;  machine_type = IMAGE_FILE_MACHINE_I386;#elif _M_X64  frame.AddrPC.Offset = context->Rip;  frame.AddrFrame.Offset = context->Rbp;  frame.AddrStack.Offset = context->Rsp;  machine_type = IMAGE_FILE_MACHINE_AMD64;#elif _M_IA64  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;#else  frame.AddrPC.Offset = context->Eip;  frame.AddrFrame.Offset = context->Ebp;  frame.AddrStack.Offset = context->Esp;  machine_type = IMAGE_FILE_MACHINE_I386;#endif
  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 這個(gè)函數(shù)，從地址轉(zhuǎn)換為函數(shù)名稱(chēng)。

利用以上幾個(gè)神器，基本上可以獲取到程序崩潰時(shí)的函數(shù)調(diào)用棧信息，定位問(wèn)題，有如神助！