c++ - 忽略 clang-tidy 中的系统头文件

Question

tldr;> 如何在 clang-tidy 中隐藏来自系统 header 的警告？

我有以下最小示例源文件，它会在系统 header 中触发一个整洁的警告:

#include <future>

int main() {
  std::promise<int> p;
  p.set_value(3);
}

在 Ubuntu 17.04 上使用 clang-tidy 4.0.0 使用 libstdc++ 7.0.1 调用它:

$ clang-tidy main.cpp -extra-arg=-std=c++14

产量

Running without flags.
1 warning generated.
/usr/lib/gcc/x86_64-linux-gnu/7.0.1/../../../../include/c++/7.0.1/mutex:693:5: warning: Address of stack memory associated with local variable '__callable' is still referred to by the global variable '__once_callable' upon returning to the caller.  This will be a dangling reference [clang-analyzer-core.StackAddressEscape]
    }
    ^
/home/user/main.cpp:5:3: note: Calling 'promise::set_value'
  p.set_value(3);
  ^
/usr/lib/gcc/x86_64-linux-gnu/7.0.1/../../../../include/c++/7.0.1/future:1094:9: note: Calling '_State_baseV2::_M_set_result'
      { _M_future->_M_set_result(_State::__setter(this, std::move(__r))); }
        ^
/usr/lib/gcc/x86_64-linux-gnu/7.0.1/../../../../include/c++/7.0.1/future:401:2: note: Calling 'call_once'
        call_once(_M_once, &_State_baseV2::_M_do_set, this,
        ^
/usr/lib/gcc/x86_64-linux-gnu/7.0.1/../../../../include/c++/7.0.1/mutex:691:11: note: Assuming '__e' is 0
      if (__e)
          ^
/usr/lib/gcc/x86_64-linux-gnu/7.0.1/../../../../include/c++/7.0.1/mutex:691:7: note: Taking false branch
      if (__e)
      ^
/usr/lib/gcc/x86_64-linux-gnu/7.0.1/../../../../include/c++/7.0.1/mutex:693:5: note: Address of stack memory associated with local variable '__callable' is still referred to by the global variable '__once_callable' upon returning to the caller.  This will be a dangling reference
    }

我想在系统标题中隐藏警告。我尝试了以下方法:

$ clang-tidy -extra-arg=-std=c++14 main.cpp -header-filter=$(realpath .) -system-headers=0

但警告仍然显示。

Answer 1

我也遇到了这个问题，并花了一些时间试图解决这个问题，但我看不到在 clang-tidy 中禁用此类警告的方法。

通过阅读 this discussion on the LLVM issue tracker regarding a similar issue ，我得到的印象是问题在于从 clang-tidy 的角度来看，警告实际上位于 main.cpp ，因为对 set_value 的调用是从那里开始的。

我的解决方法是禁用clang-tidy中的静态分析检查，并使用scan-build utility运行clang的静态分析，这似乎可以避免这些问题。例如，使用您的 main.cpp :

$ scan-build-3.9 clang++ -std=c++14 main.cpp 
scan-build: Using '/usr/lib/llvm-3.9/bin/clang' for static analysis
In file included from main.cpp:1:
In file included from /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/future:39:
/usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/mutex:621:11: warning: Address of stack memory associated with local variable '__callable' is still referred to by the global variable '__once_callable' upon returning to the caller.  This will be a dangling reference
      if (__e)
          ^~~
1 warning generated.
scan-build: Removing directory '/tmp/scan-build-2017-12-02-112018-13035-1' because it contains no reports.
scan-build: No bugs found.

分析器在系统 header 中发现了相同的错误，但它足够聪明，不会将其包含在最终报告中。 (“未发现错误”)

如果您对样式指南类型的警告感兴趣，您仍然需要单独运行 clang-tidy，例如 modernize-* 或 readability-* 。