铛似乎使用gcc库 [英] clang seems to use the gcc libraries

问题描述

这是我第一次使用 clang 。我注意到从clang引用std库的任何错误如下所示：

  / usr / bin /../ lib /gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/ostream:245:7：
 ^^^ ^^^ ^^^ 
  

所以它看起来像是clang链接 - 或者至少包括 - gcc库。

我使用的命令： clang ++ -c -Wall -Wextra -Werror -g test.cpp -o test.o 。 （该程序有一个故意的错误只是为了证明这一点）。

这怎么可能？我可以做些什么来使 clang 使用它自己的库（但不能打破gcc）？

---

其他信息：

我在Ubuntu 14.04机器上。

  clang ++ --version 
 Ubuntu clang版本3.5-1ubuntu1（trunk）（基于LLVM 3.5）
目标：x86_64-pc-linux-gnu 
线程模型： posix 
 
 g ++ --version 
 g ++（Ubuntu 4.8.2-19ubuntu1）4.8.2 
版权所有（C）2013 Free Software Foundation，Inc. 
  

我以前安装过几个版本（同时，它们用于 update-alternatives gcc 加上 apt-get 。现在我只有 4.8 （我已经卸载了其他）。那我可以搞砸了吗？我从来没有安装过clang（我猜这是默认的Ubuntu）。

澄清：正确的程序编译并运行在 clang ++

code>。

进一步的测试：我知道 gcc 没有实现像 is_trivially_constructible 并在 iostream 标准c ++ 11库（https://gcc.gnu.org/onlinedocs/libstdc++/manual/status.html ），并且该铿锵有完整的C ++ 11符合库所以我测试了那些用clang编译的代码，并且我得到了相应的gcc错误，这只能证实clang正在使用gcc库。

一个非常基本的程序

  #include< iostream> 
使用namespace std; 
 
 int main（）{
 cout<< Yada Yada<< ENDL; 
返回0; 
} 
  

在编译时使用-std = c ++ 1y时出现此错误++：

 从/usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/包含的文件中。 /../../../include/c++/4.8/iostream:39：
 ... 
 /usr/bin/../lib/gcc/x86_64-linux-gnu/4.8 /../../../../include/c++/4.8/cstdio:120:11：错误：全局命名空间中没有名为'gets'的成员使用:: gets获取; 
 ~~ ^ 
  

所以现在我无法用 c ++ 1y in clang。

解决方案

您需要安装 libc ++ 并让clang与 -stdlib = libc ++一起使用

This is the first time I use clang. What I notices is that any error from clang referencing the std library looks like this:

/usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/ostream:245:7:
                ^^^                  ^^^                         ^^^

So it looks like clang links — or at least includes — the gcc libraries.

The command I used: clang++ -c -Wall -Wextra -Werror -g test.cpp -o test.o. (The program had a intentional error just to prove this).

How is this possible? What can I do to make clang use its own libraries (but not break gcc)?

---

Additional information:

I am on a Ubuntu 14.04 machine.

clang++ --version
Ubuntu clang version 3.5-1ubuntu1 (trunk) (based on LLVM 3.5)
Target: x86_64-pc-linux-gnu
Thread model: posix

g++ --version
g++ (Ubuntu 4.8.2-19ubuntu1) 4.8.2
Copyright (C) 2013 Free Software Foundation, Inc.

I had previously installed several versions (at the same time, used them with update-alternatives) of gcc with apt-get. Right now I have only 4.8 (I have uninstalled the others). Could I have messed up something then? I have never installed clang (I guess it is default with Ubuntu).

Just to clarify: the correct programs compile and run in clang++.

Further tests: I know that gcc didn’t implement yet types like is_trivially_constructible and move operations on iostream in their standard c++11 library (https://gcc.gnu.org/onlinedocs/libstdc++/manual/status.html) and that clang has full c++11 conforming library so I tested those compiling with clang and I got the corresponding gcc errors, which only confirms that clang is using gcc libraries.

A very basic program

#include <iostream>
using namespace std;

int main() { 
  cout << "Yada Yada" << endl;
  return 0;
}

gives this error when compiling with -std=c++1y in clang++:

In file included from /usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/iostream:39:
...
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/cstdio:120:11: error: no member named 'gets' in the global namespace
  using ::gets;
        ~~^

So right now I can’t compile anything with c++1y in clang.

解决方案

You need to install libc++ and make clang use it with -stdlib=libc++

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