文章/答案/技术大牛

发布

社区首页 >问答首页 >在Clang++中定位iostream :致命错误：“iostream”文件未找到

问在Clang++中定位iostream :致命错误：“iostream”文件未找到
EN

Stack Overflow用户

提问于 2019-02-04 17:33:24

回答 5查看 19.8K关注 0票数 14

我编写了以下简单的C++程序：

#include <iostream>

using namespace std;

int main() {
    cout << "Hello, World" << endl;
    return 0;
}

当我用g++编译它时，它工作得很好。当我尝试用Clang++编译时，我会得到以下错误：

main.cpp:1:10: fatal error: 'iostream' file not found
#include <iostream>
         ^~~~~~~~~~
1 error generated.

使用-v参数运行时，我看到以下内容：

ignoring nonexistent directory "/usr/bin/../lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/x86_64-linux-gnu"
ignoring nonexistent directory "/usr/bin/../lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/backward"
ignoring nonexistent directory "/include"
ignoring duplicate directory "/usr/include/clang/6.0.0/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/bin/../lib/gcc/x86_64-linux-gnu/8/../../../../include/c++
 /usr/include/clang/6.0.0/include
 /usr/local/include
 /usr/include/x86_64-linux-gnu
 /usr/include
End of search list.

单独查看这些文件夹，我发现在/usr/bin/../lib/gcc/x86_64-linux-gnu/8/../../../../include/c++ (或者更简单地说，在/usr/include/c++中)中，我有以下目录：

drwxr-xr-x   5 root root 4.0K Feb  4 09:38 .
drwxr-xr-x 101 root root  20K Feb  4 12:22 ..
drwxr-xr-x  12 root root  12K May 24  2018 5
drwxr-xr-x  12 root root  12K Oct  9 14:53 7
drwxr-xr-x   5 root root 4.0K Feb  4 09:38 v1
lrwxrwxrwx   1 root root    1 Apr 11  2018 5.5.0 -> 5
lrwxrwxrwx   1 root root    1 Apr 15  2018 7.3.0 -> 7

在每个5、7和v1目录中都存在一个名为iostream的文件。

在/usr/include/x86_64-linux-gnu中还有一个c++目录，它与这个目录非常相似( 5、7、5.5.0和7.3.0目录)。

在/usr/include中也有一个c++目录，它看起来与上面的两个目录完全一样

我不知道我的dev环境是如何变得如此混乱，但此时我只想知道如何修复它，以便Clang++能够成功地找到这9个iostream实例中的一个，而不是抛出一个不存在的错误。我需要添加一个环境变量来告诉Clang在哪里查找吗？我是否需要传递一个命令行参数来告诉Clang递归搜索？

最新情况(1)

当我尝试使用libc++进行构建时，会得到以下错误：

$> clang++ -stdlib=libc++ main.cpp
/usr/bin/ld: cannot find -lc++abi
clang: error: linker command failed with exit code 1 (use -v to see invocation)

当我尝试使用手动重写的包含路径构建时，我会得到以下错误：

$> clang++ -isystem /usr/include/c++/7 -isystem /usr/include/x86_64-linux-gnu/c++/7 main.cpp
/usr/bin/ld: cannot find -lstdc++
clang: error: linker command failed with exit code 1 (use -v to see invocation)

当我同时尝试这两种方法时，我会得到以下(非常大的)错误：

$> clang++ -isystem /usr/include/c++/7 -isystem /usr/include/x86_64-linux-gnu/c++/7 -stdlib=libc++ main.cpp
In file included from main.cpp:1:
In file included from /usr/include/c++/7/iostream:39:
In file included from /usr/include/c++/7/ostream:38:
In file included from /usr/include/c++/7/ios:42:
In file included from /usr/include/c++/7/bits/ios_base.h:41:
In file included from /usr/include/c++/7/bits/locale_classes.h:40:
In file included from /usr/include/c++/7/string:52:
In file included from /usr/include/c++/7/bits/basic_string.h:6352:
In file included from /usr/include/c++/7/ext/string_conversions.h:41:
In file included from /usr/include/c++/7/cstdlib:77:
/usr/include/c++/7/bits/std_abs.h:56:3: error: declaration conflicts with target of using declaration already in scope
  abs(long __i) { return __builtin_labs(__i); }
  ^
/usr/include/c++/v1/stdlib.h:111:44: note: target of using declaration
inline _LIBCPP_INLINE_VISIBILITY long      abs(     long __x) _NOEXCEPT {return  labs(__x);}
                                           ^
/usr/include/c++/7/bits/std_abs.h:52:11: note: using declaration
  using ::abs;
          ^
/usr/include/c++/7/bits/std_abs.h:61:3: error: declaration conflicts with target of using declaration already in scope
  abs(long long __x) { return __builtin_llabs (__x); }
  ^
/usr/include/c++/v1/stdlib.h:113:44: note: target of using declaration
inline _LIBCPP_INLINE_VISIBILITY long long abs(long long __x) _NOEXCEPT {return llabs(__x);}
                                           ^
/usr/include/c++/7/bits/std_abs.h:52:11: note: using declaration
  using ::abs;
          ^
In file included from main.cpp:1:
In file included from /usr/include/c++/7/iostream:39:
In file included from /usr/include/c++/7/ostream:38:
In file included from /usr/include/c++/7/ios:42:
In file included from /usr/include/c++/7/bits/ios_base.h:41:
In file included from /usr/include/c++/7/bits/locale_classes.h:40:
In file included from /usr/include/c++/7/string:52:
In file included from /usr/include/c++/7/bits/basic_string.h:6352:
In file included from /usr/include/c++/7/ext/string_conversions.h:41:
/usr/include/c++/7/cstdlib:177:3: error: declaration conflicts with target of using declaration already in scope
  div(long __i, long __j) { return ldiv(__i, __j); }
  ^
/usr/include/c++/v1/stdlib.h:116:42: note: target of using declaration
inline _LIBCPP_INLINE_VISIBILITY  ldiv_t div(     long __x,      long __y) _NOEXCEPT {return  ldiv(__x, __y);}
                                         ^
/usr/include/c++/7/cstdlib:145:11: note: using declaration
  using ::div;
          ^

作为提醒，我真的只是想编译Hello

我还尝试使用以下命令卸载和重新安装Clang：

$> sudo apt-get purge --auto-remove clang
$> sudo apt-get update
$> sudo apt-get install clang

这没有效果。我正在运行Ubuntu18.04，我不知道哪里出了问题，也不知道从哪里开始修复它。我的建筑环境一团糟。

如果可能的话，我希望让Clang工作，而不是回到使用G++，因为我的IDE似乎是自动检测Clang并使用它进行语法检查。这意味着我编写的每个C++程序在第一行上都有一个致命错误("iostream not“)，而文件的其余部分没有检查，因为第一个是致命错误。

回答 5

Stack Overflow用户

回答已采纳

发布于 2019-02-28 13:25:09

我也被这个问题困扰了很久，time.You应该尝试删除文件夹(cd /usr/lib/gcc/aarch64-linux-gnu/8)。clang++不能工作的原因是这个文件夹不包含libstdc++.a。

clang version 6.0.0-1ubuntu2 (tags/RELEASE_600/final)
Target: aarch64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
Found candidate GCC installation: /usr/bin/../lib/gcc/aarch64-linux-gnu/5
Found candidate GCC installation: /usr/bin/../lib/gcc/aarch64-linux-gnu/5.5.0
Found candidate GCC installation: /usr/bin/../lib/gcc/aarch64-linux-gnu/6
Found candidate GCC installation: /usr/bin/../lib/gcc/aarch64-linux-gnu/6.5.0
Found candidate GCC installation: /usr/bin/../lib/gcc/aarch64-linux-gnu/7
Found candidate GCC installation: /usr/bin/../lib/gcc/aarch64-linux-gnu/7.3.0
Found candidate GCC installation: /usr/lib/gcc/aarch64-linux-gnu/5
Found candidate GCC installation: /usr/lib/gcc/aarch64-linux-gnu/5.5.0
Found candidate GCC installation: /usr/lib/gcc/aarch64-linux-gnu/6
Found candidate GCC installation: /usr/lib/gcc/aarch64-linux-gnu/6.5.0
Found candidate GCC installation: /usr/lib/gcc/aarch64-linux-gnu/7
Found candidate GCC installation: /usr/lib/gcc/aarch64-linux-gnu/7.3.0
Selected GCC installation: /usr/bin/../lib/gcc/aarch64-linux-gnu/7.3.0

检查/usr/lib/gcc/aarch64-linux-gnu/ clang++中的所有文件夹，确保最后一个文件夹中有libstdc++.a。

票数 15

Stack Overflow用户

发布于 2019-11-13 02:28:49

我发现clang使用的是/usr/lib/gcc/x86_64-linux-gnu/8中的安装(使用clang++ -v)，实际上这并不包含文件libstdc++.a。我没有按照另一个答案的建议删除整个目录，我只安装了libstdc++-8-dev。

我在Ubuntu 18.04，gcc已经安装好了。

票数 11

Stack Overflow用户

发布于 2019-10-11 10:02:06

首先找到您的版本(path)：

ls /usr/include/c++/

输出(您的版本可能不同)：

然后添加包含路径，并将11替换为您的版本，例如：

-I/usr/include/c++/11 
-I/usr/include/x86_64-linux-gnu/c++/11

构建

这在Linux上适用于我(并用您的版本替换11 )：

clang++ -I/usr/include/c++/11 -I/usr/include/x86_64-linux-gnu/c++/11 -L /usr/lib/gcc/x86_64-linux-gnu/11 main.cpp -o main

通过这个简单的例子(main.cpp)：

#include <iostream>
int main() { std::cout << "Hi\n"; }

此外，您还可以使用路径 (并用您的版本替换11 )：

export CPLUS_INCLUDE_PATH=/usr/include/c++/11:/usr/include/x86_64-linux-gnu/c++/11

然后这就起作用了：

clang++ main.cpp -o main

运行：

./main

并见：

https://superuser.com/questions/358255/bash-environment-variable-to-include-path-of-c-libraries

如何查询clang++的默认包含路径？

Clang没有看到基本的标题

https://askubuntu.com/questions/516801/clang-fails-to-compile-simple-hello-world-c-program

我希望这能帮上忙。

票数 7

页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持

原文链接：

https://stackoverflow.com/questions/54521402

复制

相似问题

问在Clang++中定位iostream :致命错误：“iostream”文件未找到
EN

回答 5

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问在Clang++中定位iostream :致命错误：“iostream”文件未找到EN

回答 5

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问在Clang++中定位iostream :致命错误：“iostream”文件未找到
EN