如何正确添加包含目录与CMake

大约一年前，我问过CMake中的头依赖关系。

我最近意识到，问题似乎是CMake认为这些头文件是项目的外部文件。至少，在生成Code::Blocks项目时，头文件不会出现在项目中(源文件会出现)。因此，在我看来，CMake认为这些头文件是项目的外部，并没有在依赖项中跟踪它们。

在CMake教程中快速搜索只指向include_directories，这似乎不是我想要的…

向CMake发出特定目录包含要包含的头文件，以及生成的Makefile应该跟踪这些头文件的正确方法是什么?

当前回答

如果与其他创建Makefile的方法(例如make或qmake)相比，CMake更像是一种脚本语言。它不像Python那样酷，但仍然很酷。

如果在各种开源项目中寻找人们如何包含目录，就没有“适当的方法”这样的东西。但是有两种方法。

Crude include_directories will append a directory to the current project and all other descendant projects which you will append via a series of add_subdirectory commands. Sometimes people say that such approach is legacy. A more elegant way is with target_include_directories. It allows to append a directory for a specific project/target without (maybe) unnecessary inheritance or clashing of various include directories. Also allow to perform even a subtle configuration and append one of the following markers for this command.

PRIVATE -仅用于此指定的构建目标

PUBLIC -用于指定目标和与此项目相关的目标

INTERFACE——仅用于与当前项目链接的目标

PS:

这两个命令都允许将目录标记为SYSTEM，以提示指定的目录是否包含警告与您无关。类似的答案是其他成对的命令target_compile_definitions/add_definitions, target_compile_options/CMAKE_C_FLAGS

2017-08-11 13:49:21

其他回答

项目结构

.
├── CMakeLists.txt
├── external //We simulate that code is provided by an "external" library outside of src
│   ├── CMakeLists.txt
│   ├── conversion.cpp
│   ├── conversion.hpp
│   └── README.md
├── src
│   ├── CMakeLists.txt
│   ├── evolution   //propagates the system in a time step
│   │   ├── CMakeLists.txt
│   │   ├── evolution.cpp
│   │   └── evolution.hpp
│   ├── initial    //produces the initial state
│   │   ├── CMakeLists.txt
│   │   ├── initial.cpp
│   │   └── initial.hpp
│   ├── io   //contains a function to print a row
│   │   ├── CMakeLists.txt
│   │   ├── io.cpp
│   │   └── io.hpp
│   ├── main.cpp      //the main function
│   └── parser   //parses the command-line input
│       ├── CMakeLists.txt
│       ├── parser.cpp
│       └── parser.hpp
└── tests  //contains two unit tests using the Catch2 library
    ├── catch.hpp
    ├── CMakeLists.txt
    └── test.cpp

怎么做

1. 顶层的CMakeLists.txt非常类似于配方1，代码重用函数和宏

cmake_minimum_required(VERSION 3.5 FATAL_ERROR)
  
project(recipe-07 LANGUAGES CXX)

set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_EXTENSIONS OFF)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

include(GNUInstallDirs)
set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY
  ${CMAKE_BINARY_DIR}/${CMAKE_INSTALL_LIBDIR})
set(CMAKE_LIBRARY_OUTPUT_DIRECTORY
  ${CMAKE_BINARY_DIR}/${CMAKE_INSTALL_LIBDIR})
set(CMAKE_RUNTIME_OUTPUT_DIRECTORY
  ${CMAKE_BINARY_DIR}/${CMAKE_INSTALL_BINDIR})

# defines targets and sources
add_subdirectory(src)

# contains an "external" library we will link to
add_subdirectory(external)

# enable testing and define tests
enable_testing()
add_subdirectory(tests)

2.目标和源定义在src/CMakeLists.txt中(转换目标除外)

add_executable(automata main.cpp)
  
add_subdirectory(evolution)
add_subdirectory(initial)
add_subdirectory(io)
add_subdirectory(parser)

target_link_libraries(automata
  PRIVATE
    conversion
    evolution
    initial
    io
    parser
  )

3.转换库定义在external/CMakeLists.txt中

add_library(conversion "")

target_sources(conversion
  PRIVATE
    ${CMAKE_CURRENT_LIST_DIR}/conversion.cpp
  PUBLIC
    ${CMAKE_CURRENT_LIST_DIR}/conversion.hpp
  )

target_include_directories(conversion
  PUBLIC
    ${CMAKE_CURRENT_LIST_DIR}
  )

4.src/CMakeLists.txt文件添加了更多的子目录，这些子目录又包含CMakeLists.txt文件。它们的结构都很相似;src/evolution/CMakeLists.txt包含以下内容:

add_library(evolution "")

target_sources(evolution
  PRIVATE
    ${CMAKE_CURRENT_LIST_DIR}/evolution.cpp
  PUBLIC
    ${CMAKE_CURRENT_LIST_DIR}/evolution.hpp
  )
target_include_directories(evolution
  PUBLIC
    ${CMAKE_CURRENT_LIST_DIR}
  )

5.单元测试注册在tests/CMakeLists.txt中

add_executable(cpp_test test.cpp)

target_link_libraries(cpp_test evolution)

add_test(
  NAME
    test_evolution
  COMMAND
    $<TARGET_FILE:cpp_test>
  )

如何运行它

$ mkdir -p build
$ cd build
$ cmake ..
$ cmake --build .

参考网址:https://github.com/sun1211/cmake_with_add_subdirectory

2021-07-13 10:14:31

在更新的CMake版本中，我们可以将包含路径限制为target，例如:

target_include_directories(MyApp PRIVATE "${CMAKE_CURRENT_LIST_DIR}/myFolder")

我的意思是，如果CMakeLists.txt有多个目标，否则，包含路径不与其他CMakeLists.txt脚本共享，它足以做一些事情，如:

include_directories("${CMAKE_CURRENT_LIST_DIR}/myFolder")

然而，也许我们可以模拟target_include_directories(…)在CMake 2.8.10或更老版本中的作用，比如:

set_property(
    TARGET MyApp
    APPEND PROPERTY
        INCLUDE_DIRECTORIES "${CMAKE_CURRENT_LIST_DIR}/myFolder"
)

所有这些都完成了，但似乎如果你想要源文件被重新编译，一旦他们使用的任何头文件被改变，所有这样的头文件也需要添加到每个目标，比如:

set(SOURCES src/main.cpp)

set(HEADERS
    ${CMAKE_CURRENT_LIST_DIR}/myFolder/myHeaderFile.h
    ${CMAKE_CURRENT_LIST_DIR}/myFolder/myOtherHeader.h
)

add_executable(MyApp ${SOURCES} ${HEADERS})

我的意思是，如果CMake愿意，它可以自动检测到这样的头文件，因为它无论如何都会解析项目的C/ c++文件。

2022-11-12 10:27:10

必须做两件事。

首先添加要包含的目录:

target_include_directories(test PRIVATE ${YOUR_DIRECTORY})

如果你被一个非常旧的CMake版本(2.8.10或更老)所困，不支持target_include_directories，你也可以使用遗留的include_directories来代替:

include_directories(${YOUR_DIRECTORY})

然后你还必须将头文件添加到当前目标的源文件列表中，例如:

set(SOURCES file.cpp file2.cpp ${YOUR_DIRECTORY}/file1.h ${YOUR_DIRECTORY}/file2.h)
add_executable(test ${SOURCES})

这样，头文件将作为依赖项出现在Makefile中，例如，如果生成了一个Visual Studio项目，头文件也将作为依赖项出现在生成的Visual Studio项目中。

如何使用这些头文件的几个目标:

set(HEADER_FILES ${YOUR_DIRECTORY}/file1.h ${YOUR_DIRECTORY}/file2.h)

add_library(mylib libsrc.cpp ${HEADER_FILES})
target_include_directories(mylib PRIVATE ${YOUR_DIRECTORY})
add_executable(myexec execfile.cpp ${HEADER_FILES})
target_include_directories(myexec PRIVATE ${YOUR_DIRECTORY})

2012-12-04 13:09:31

首先，使用include_directories()告诉CMake将目录作为-I添加到编译命令行。其次，在add_executable()或add_library()调用中列出头文件。

举个例子，如果你的项目源在src中，你需要include中的头文件，你可以这样做:

include_directories(include)

add_executable(MyExec
  src/main.c
  src/other_source.c
  include/header1.h
  include/header2.h
)

2012-12-04 13:10:33