C++获取"分段错误"Linux x64的文件名和行号

Question

没有运行GDB,只有程序本身.

编辑:我已经看过这样的程序,但我无法想象自己该怎么做:(

Answer 1

Tommie因解决这个问题值得赞扬.

我通过使用有点标准的backtrace实用程序从GDB中分离了他的答案<execinfo.h>.

static void dumpstack(void){
    static void *backbuf[ 50 ];
    int levels;

    levels = backtrace( backbuf, 50 );
    backtrace_symbols_fd( backbuf, levels, STDERR_FILENO );

    return;
}

您可以尝试打开文件而不是写作STDERR_FILENO,但我会在崩溃的过程中避免这种繁重的工作.

在我的系统上,输出如下所示:

Shadow:code dkrauss$ ./dumpy 
0   dumpy                               0x0000000100000d81 dumpstack + 25
1   dumpy                               0x0000000100000d18 signal_handler + 47
2   libSystem.B.dylib                   0x00007fff86b1766a _sigtramp + 26
3   ???                                 0x0000000000000000 0x0 + 0
4   dumpy                               0x0000000100000a18 start + 52
FATAL: Segmentation Fault

因此,它不提供文件名+行号,但它确实提供了函数名+代码偏移量,您可以轻松地进行转换.

Answer 2

嗯......你可以尝试这样做......

struct sigaction g_sigact;

void panic(const char *fmt, ...){
    char buf[PANICBUF_LEN];
    va_list argptr;
    va_start(argptr, fmt);
    vsprintf(buf, fmt, argptr);
    va_end(argptr);
    fprintf(stderr, "%s\n", buf);
    exit(-1);
}
void init_signals(void){
    g_sigact.sa_handler = signal_handler;
    sigemptyset(&g_sigact.sa_mask);
    g_sigact.sa_flags = 0;
    sigaction(SIGINT, &g_sigact, (struct sigaction *)NULL);

    sigaddset(&g_sigact.sa_mask, SIGSEGV);
    sigaction(SIGSEGV, &g_sigact, (struct sigaction *)NULL);

    sigaddset(&g_sigact.sa_mask, SIGBUS);
    sigaction(SIGBUS, &g_sigact, (struct sigaction *)NULL);

    sigaddset(&g_sigact.sa_mask, SIGQUIT);
    sigaction(SIGQUIT, &g_sigact, (struct sigaction *)NULL);

    sigaddset(&g_sigact.sa_mask, SIGHUP);
    sigaction(SIGHUP, &g_sigact, (struct sigaction *)NULL);

    sigaddset(&g_sigact.sa_mask, SIGKILL);
    sigaction(SIGKILL, &g_sigact, (struct sigaction *)NULL);
}

static void signal_handler(int sig){
    if (sig == SIGHUP) g_keepRunning = 0;
    if (sig == SIGSEGV || sig == SIGBUS){
        dumpstack();
        panic("FATAL: %s Fault\n", (sig == SIGSEGV) ? "Segmentation" : ((sig == SIGBUS) ? "Bus" : "Unknown"));
    }
    if ((sig == SIGQUIT || (sig == SIGKILL) || (sig == SIGINT)) ;
}

static void dumpstack(void){
    /* Got this routine from http://www.whitefang.com/unix/faq_toc.html
    ** Section 6.5. Modified to redirect to file to prevent clutter
    */
    char dbx[160];
    sprintf(dbx, "echo -ne 'detach\n' | gdb --eval-command=where --pid=%d > %d.dump", getpid(), getpid());
    system(dbx);
    return;
}

捕获分段错误时,dumpstack调用并打印最新的堆栈跟踪,直至分段出现故障并重定向到具有进程的数字pid的文件....