Question

是否有任何Raspberry Pi优化/特定的回溯（）实现？我使用标准的backtrace（）代码，但期待my_backtrace函数的更详细输出。

void my_backtrace(){
     void *stack[10];
     int n = backtrace(stack, 10);
     std::cout << "Last  frames==" << n << std::endl;
     backtrace_symbols_fd(stack, n, STDOUT_FILENO);
}

Answer 1

//--There is list of options:
//a) backtrace in combination with abi::__cxa_demangle
//b) GDB
//c) [libunwind][1], [http://www.nongnu.org/libunwind/docs.html] 
//d) libbfd-dev 
//e) [backward-cpp][1], [https://github.com/bombela/backward-cpp]
//f) [libbacktrace][1], [https://github.com/ErwanLegrand/libbacktrace]
//-----------------------------------------------
#include <execinfo.h>
#include <iostream>
#include <sys/types.h>
#include <unistd.h>
#include <sstream>
#include <sys/wait.h>
//-----------------------------------------------
//Based on GDB
//-----------------------------------------------
void print_trace_gdb() {
    char pid_buf[30];
    sprintf(pid_buf, "%d", getpid());
    char name_buf[512];
    name_buf[readlink("/proc/self/exe", name_buf, 511)]=0;

    int child_pid = fork();
    if (!child_pid) {           
        dup2(2,1); // redirect output to stderr
        fprintf(stdout,"stack trace for %s pid=%s\n",name_buf, pid_buf);
        execlp("gdb", "gdb", "--batch", "-n", "-ex", "thread", "-ex", "bt", name_buf, pid_buf, NULL);
        //if gdb failed to start
        abort();
    } else {
        waitpid(child_pid,NULL,0);
    }
 }

//-----------------------------------------------
 void rec_function(int ii)
 {
     if ( ii == 0 ) {std::cout << "int value==" << ii << "\n";}
     else {rec_function(--ii);}
     print_trace_gdb();
 }

 //-----------------------------------------------
 int main()
{
   int jj=1;
   std::cout << "\n---begin test-----\n";
   std::cout << "int value==" << jj << "\n";
   rec_function(jj);
   std::cout << "---end test-----\n";
}

此代码的输出为

---begin test-----
int value==1
int value==0
stack trace for /opt/cpp/linux_backtrace_gdb pid=4181
0x00007f878b5ca4ca in waitpid () from /lib/x86_64-linux-gnu/libc.so.6
[Current thread is 1 (process 4181)]
#0  0x00007f878b5ca4ca in waitpid () from /lib/x86_64-linux-gnu/libc.so.6
#1  0x0000000000400e69 in print_trace_gdb () at linux_backtrace_gdb.cpp:25
#2  0x0000000000400ed2 in rec_function (ii=0) at linux_backtrace_gdb.cpp:34
#3  0x0000000000400ecd in rec_function (ii=0) at linux_backtrace_gdb.cpp:33
#4  0x0000000000400f29 in main () at linux_backtrace_gdb.cpp:43
stack trace for /opt/cpp/linux_backtrace_gdb pid=4181
0x00007f878b5ca4ca in waitpid () from /lib/x86_64-linux-gnu/libc.so.6
[Current thread is 1 (process 4181)]
#0  0x00007f878b5ca4ca in waitpid () from /lib/x86_64-linux-gnu/libc.so.6
#1  0x0000000000400e69 in print_trace_gdb () at linux_backtrace_gdb.cpp:25
#2  0x0000000000400ed2 in rec_function (ii=0) at linux_backtrace_gdb.cpp:34
#3  0x0000000000400f29 in main () at linux_backtrace_gdb.cpp:43
---end test-----

Raspberry Pi优化回溯（）

1 个答案: