如何使用工具include-what-you-use与CMake一起检测未使用的头文件?

The tool include-what-you-use can be used to detect unneeded headers. I am using CMake for my C++ software project. How can I instruct CMake to run include-what-you-use automatically on the source files of my software project?

可以使用包含“你使用什么”的工具来检测不需要的标题。我正在为我的c++软件项目使用CMake。我如何指示CMake在我的软件项目的源文件上自动运行包含-什么-你使用?

4 个解决方案

#1

CMake 3.3 introduced the new target property CXX_INCLUDE_WHAT_YOU_USE that can be set to the path of the program include-what-you-use. For instance this CMakeLists.txt

CMake 3.3引入了新的目标属性CXX_INCLUDE_WHAT_YOU_USE，可以将其设置为程序包含的-what-you-use的路径。例如这CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)
add_executable(hello main.cc)

find_program(iwyu_path NAMES include-what-you-use iwyu)
if(NOT iwyu_path)
  message(FATAL_ERROR "Could not find the program include-what-you-use")
endif()

set_property(TARGET hello PROPERTY CXX_INCLUDE_WHAT_YOU_USE ${iwyu_path})

is able to build the file main.cc

能够构建文件main.cc吗

#include <iostream>
#include <vector>

int main() {
  std::cout << "Hello World!" << std::endl;
  return 0;
}

and at the same time have include-what-you-use give out a warning that the included header vector is not needed.

与此同时，包含—使用—发出一个警告，其中包含的头向量是不需要的。

user@ubuntu:/tmp$ ls ~/hello
CMakeLists.txt  main.cc
user@ubuntu:/tmp$ mkdir /tmp/build
user@ubuntu:/tmp$ cd /tmp/build
user@ubuntu:/tmp/build$ ~/cmake-3.3.0-rc2-Linux-x86_64/bin/cmake ~/hello
-- The C compiler identification is GNU 4.9.2
-- The CXX compiler identification is GNU 4.9.2
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Configuring done
-- Generating done
-- Build files have been written to: /tmp/build
user@ubuntu:/tmp/build$ make
Scanning dependencies of target hello
[ 50%] Building CXX object CMakeFiles/hello.dir/main.cc.o
Warning: include-what-you-use reported diagnostics:

/home/user/hello/main.cc should add these lines:

/home/user/hello/main.cc should remove these lines:
- #include <vector>  // lines 2-2

The full include-list for /home/user/hello/main.cc:
#include <iostream>  // for operator<<, basic_ostream, cout, endl, ostream
---

[100%] Linking CXX executable hello
[100%] Built target hello
user@ubuntu:/tmp/build$ ./hello 
Hello World!
user@ubuntu:/tmp/build$

If you want to pass custom options to include-what-you-use, like for instance --mapping_file you can do it via

如果您想传递自定义选项来包含您使用的内容，比如mapping_file，您可以通过它来实现

set(iwyu_path_and_options
    ${iwyu_path}
    -Xiwyu
    --mapping_file=${my_mapping})

set_property(TARGET hello
    PROPERTY CXX_INCLUDE_WHAT_YOU_USE ${iwyu_path_and_options})

#2

If you don't have access to CMake 3.3, include-what-you-use comes with a python tool called iwyu_tool.py which can do what you want.

如果您无法访问CMake 3.3，那么您可以使用一个名为iwyu_tool的python工具。py可以做你想做的。

It works by parsing a clang compilation database, which is easily produced with CMake.

它通过解析clang编译数据库来工作，该数据库很容易使用CMake生成。

Running the tool manually

Assuming you already have a CMake build dir for your project, you first need to tell CMake to produce the compilation database:

假设您的项目已经有一个CMake build dir，您首先需要告诉CMake生成编译数据库:

$ cd build
$ cmake -DCMAKE_EXPORT_COMPILE_COMMANDS=ON .

This generates a file, compile_commands.json containing compiler invocations for every object file in your project. You don't need to rebuild the project.

这会生成一个名为compile_commands的文件。json包含对项目中的每个对象文件的编译器调用。您不需要重新构建项目。

You can now run include-what-you-use on your project by running the python tool on your build directory:

现在，您可以在您的构建目录上运行python工具，从而在项目上运行包含的内容:

$ python /path/to/iwyu_tool.py -p .

Adding a custom target to your cmake project

The following snippet can be used to add an iwyu target to a cmake project.

以下代码片段可用于向cmake项目添加iwyu目标。

# Generate clang compilation database
set(CMAKE_EXPORT_COMPILE_COMMANDS ON)

find_package(PythonInterp)
find_program(iwyu_tool_path NAMES iwyu_tool.py)
if (iwyu_tool_path AND PYTHONINTERP_FOUND)
  add_custom_target(iwyu
    ALL      # Remove ALL if you don't iwyu to be run by default.
    COMMAND "${PYTHON_EXECUTABLE}" "${iwyu_tool_path}" -p "${CMAKE_BINARY_DIR}"
    COMMENT "Running include-what-you-use tool"
    VERBATIM
  )
endif()

Notes

The include-what-you-use binary needs to be in your path for any of the above to work properly.

要使上述任何一种方法正常工作，您所使用的二进制代码都需要在您的路径中。

#3

You can also enable it globally outside the cmake script by setting the cmake variable:

您还可以通过设置cmake变量在cmake脚本之外的全局启用它:

cmake -DCMAKE_CXX_INCLUDE_WHAT_YOU_USE="iwyu" <builddir> 

It will then call it on each CXX target.

然后在每个CXX目标上调用它。

#4

I extended the source code from Alastair Harrison, in order to create a reusable solution. I've came up with the following that should work with all CMake versions:

我扩展了Alastair Harrison的源代码，以创建一个可重用的解决方案。我想到了下面的方法，它应该适用于所有CMake版本:

File iwyu.cmake:

文件iwyu.cmake:

#.rst:
# include-what-you-use (iwyu)
# ----------------------------
#
# Allows to run the static code analyzer `include-what-you-use (iwyu)
# <http://include-what-you-use.org>`_ as a custom target with the build system
# `CMake <http://cmake.org>`_.
#
# .. topic:: Dependencies
#
#  This module requires the following *CMake* modules:
#
#  * ``FindPythonInterp``
#
# .. topic:: Contributors
#
#  * Florian Wolters <[e-mail]>

#===============================================================================
# Copyright 2015 Florian Wolters
#
# Distributed under the Boost Software License, Version 1.0. (See accompanying
# file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
#===============================================================================

# ------------------------------------------------------------------------------
# Include guard for this file.
# ------------------------------------------------------------------------------

if(iwyu_included)
  return()
endif()

set(iwyu_included TRUE)

option(BUILD_IWYU
       "Run the include-what-you-use static analyzer on the source code of the project."
       OFF)

function(iwyu_enable)
  set(iwyu_EXECUTABLE_NAME include-what-you-use)
  find_program(iwyu_EXECUTABLE ${iwyu_EXECUTABLE_NAME})

  if(iwyu_EXECUTABLE)
    # This is not exactly the same behavior as with CMake v3.3, since here all
    # compiled targets are analyzed.
    set(iwyu_tool_EXECUTABLE_NAME iwyu_tool.py)

    find_package(PythonInterp)
    find_program(iwyu_tool_EXECUTABLE ${iwyu_tool_EXECUTABLE_NAME})

    if(PYTHONINTERP_FOUND AND iwyu_tool_EXECUTABLE)
      set(CMAKE_EXPORT_COMPILE_COMMANDS ON PARENT_SCOPE)

      add_custom_target(iwyu
                        ALL
                        COMMAND "${PYTHON_EXECUTABLE}" "${iwyu_tool_EXECUTABLE}" -p "${CMAKE_BINARY_DIR}"
                        COMMENT "Running the ${iwyu_tool_EXECUTABLE_NAME} compilation database driver"
                        VERBATIM)
    else()
      message(STATUS
              "Unable to find the Python interpreter and/or the ${iwyu_tool_EXECUTABLE_NAME} script")
    endif()
  else()
    message(STATUS "Unable to find the ${iwyu_EXECUTABLE_NAME} executable")
  endif()
endfunction()

File CMakeLists.txt:

文件CMakeLists.txt:

cmake_minimum_required(VERSION 3.0)

include(iwyu.cmake)

project(hello_world)
add_executable(${PROJECT_NAME} main.cc)

if(BUILD_IWYU)
  iwyu_enable()
endif()

Invoke CMake as follows to run include-what-you-use when the all target is invoked:

调用CMake，如下所示，在调用所有目标时运行include-what-you-use:

cmake -DBUILD_IWYU=ON <path-to-source>
cmake --build . --target all

The output should be as follows:

输出应如下:

-- Configuring done
-- Generating done
-- Build files have been written to: /home/wolters/workspace/include-what-you-use_example/build
[ 66%] Built target hello_world
[100%] Running the iwyu_tool.py compilation database driver

/home/wolters/workspace/include-what-you-use_example/develop/main.cc should add these lines:

/home/wolters/workspace/include-what-you-use_example/develop/main.cc should remove these lines:
- #include <vector>  // lines 1-1

The full include-list for /home/wolters/workspace/include-what-you-use_example/develop/main.cc:
#include <iostream>  // for operator<<, basic_ostream, cout, endl, ostream
---
[100%] Built target iwyu

Edit 2015-08-19: The approach with the CMake property <LANG>_INCLUDE_WHAT_YOU_USE did not work for me with CMake version 3.3.1. Therefore I updated the solution.

编辑2015-08-19:CMake属性 _INCLUDE_WHAT_YOU_USE的方法在CMake版本3.3.1中对我不起作用。因此我更新了解决方案。

Edit 2015-09-30: The output was wrong, since my include-what-you-use installation was broken. The include-what-you-use and iwyu_tool.py files have to be in the same directory as clang, clang++, etc.

编辑2015-09-30:输出错误，因为我的include-what-you-use安装坏了。include-what-you-use iwyu_tool。py文件必须在与clang、clang+等相同的目录中。