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?
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
这招对我很管用:
set(SOURCE main.cpp)
add_executable(${PROJECT_NAME} ${SOURCE})
# target_include_directories must be added AFTER add_executable
target_include_directories(${PROJECT_NAME} PUBLIC ${INTERNAL_INCLUDES})
其他回答
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
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
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
)
不要忘记包含${CMAKE_CURRENT_LIST_DIR}。 这就是给我带来麻烦的原因。
示例应该是这样的:
target_include_directories(projectname
PUBLIC "${CMAKE_CURRENT_LIST_DIR}/include"
)
PUBLIC用于您想要包含在父项目中的依赖项。 对于那些你不喜欢的人来说是私密的。
这招对我很管用:
set(SOURCE main.cpp)
add_executable(${PROJECT_NAME} ${SOURCE})
# target_include_directories must be added AFTER add_executable
target_include_directories(${PROJECT_NAME} PUBLIC ${INTERNAL_INCLUDES})