c++ - directory_iterator 遇到段错误

Question

这是我的代码:

#include <iostream>
#include <filesystem>

int main(int argc, char *argv[]) {
    auto iter = std::filesystem::directory_iterator("foo");
    for (auto &entry : iter) {
        std::cout << entry.path();
    }
}

当我运行它并且目录 foo 存在时，我得到一个 SIGSEGV。所以我启动了 gdb:

(gdb) run
Starting program: /home/krausefx/a.out 

Program received signal SIGSEGV, Segmentation fault.
0x0000555555556a87 in std::vector<std::filesystem::__cxx11::path::_Cmpt, std::allocator<std::filesystem::__cxx11::path::_Cmpt> >::~vector (
    this=0x23) at /usr/include/c++/8/bits/stl_vector.h:567
567     std::_Destroy(this->_M_impl._M_start, this->_M_impl._M_finish,
(gdb) backtrace
#0  0x0000555555556a87 in std::vector<std::filesystem::__cxx11::path::_Cmpt, std::allocator<std::filesystem::__cxx11::path::_Cmpt> >::~vector (
    this=0x23) at /usr/include/c++/8/bits/stl_vector.h:567
#1  0x00005555555566aa in std::filesystem::__cxx11::path::~path (this=0x3) at /usr/include/c++/8/bits/fs_path.h:208
#2  0x0000555555557ebe in std::filesystem::__cxx11::path::_Cmpt::~_Cmpt (this=<incomplete type>) at /usr/include/c++/8/bits/fs_path.h:643
#3  0x0000555555557ed9 in std::_Destroy<std::filesystem::__cxx11::path::_Cmpt> (__pointer=0x3) at /usr/include/c++/8/bits/stl_construct.h:98
#4  0x0000555555557ced in std::_Destroy_aux<false>::__destroy<std::filesystem::__cxx11::path::_Cmpt*> (__first=0x3, __last=0x0)
    at /usr/include/c++/8/bits/stl_construct.h:108
#5  0x00005555555576de in std::_Destroy<std::filesystem::__cxx11::path::_Cmpt*> (__first=0x3, __last=0x0)
    at /usr/include/c++/8/bits/stl_construct.h:137
#6  0x0000555555556fb9 in std::_Destroy<std::filesystem::__cxx11::path::_Cmpt*, std::filesystem::__cxx11::path::_Cmpt> (__first=0x3, __last=0x0)
    at /usr/include/c++/8/bits/stl_construct.h:206
#7  0x0000555555556a9d in std::vector<std::filesystem::__cxx11::path::_Cmpt, std::allocator<std::filesystem::__cxx11::path::_Cmpt> >::~vector (
    this=0x7fffffffdcf0) at /usr/include/c++/8/bits/stl_vector.h:567
#8  0x00005555555566aa in std::filesystem::__cxx11::path::~path (this=0x7fffffffdcd0) at /usr/include/c++/8/bits/fs_path.h:208
#9  0x000055555555630d in main (argc=32767, argv=0x7ffff7fadf40 <std::wcout>) at test.cpp:5
(gdb) p this
$1 = (vector * const) 0x23

显然，当初始化 directory_iterator 时，std::filesystem::path 的析构函数由于某种原因被调用，而在其中某处， 的析构函数被调用code>std::vector 在 0x23 的 this 值上被调用，这显然是一件坏事并导致 SIGSEGV。

这里发生了什么？难道我做错了什么？这是编译器错误吗(编译器是 g++ 8.3.0)？

Answer 1

我检查过 directory_iterator 在 Ubuntu 下使用 GCC 8 工作正常。

一定要在编译时加上链接器标志-lstdc++fs。

如果您没有成功结束编译，但至少在我的系统中，我会在开始迭代时遇到段错误。