工具►cmake

cmake 使用

简介

CMake是一个比make更高级的编译配置工具，它可以根据不同平台、不同的编译器，生成相应的Makefile或者vcproj项目。通过编写CMakeLists.txt，可以控制生成的Makefile，从而控制编译过程。CMake自动生成的Makefile不仅可以通过make命令构建项目生成目标文件，还支持安装（make install）、测试安装的程序是否能正确执行（make test，或者ctest）、生成当前平台的安装包（make package）、生成源码包（make package_source）、产生Dashboard显示数据并上传等高级功能，只要在CMakeLists.txt中简单配置，就可以完成很多复杂的功能，包括写测试用例。如果有嵌套目录，子目录下可以有自己的CMakeLists.txt。

步骤

  • 编写CMakeLists.txt
  • 执行命令cmake PATH 或 ccmake PATH 生成Makefile
  • 使用make命令编译，make -j4 指定编译并行度
  • 使用 make install 安装

编译

指定安装路径

参考 这里

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# 3.15 +
$ cmake --install /path/to/build --prefix /path/to/install [--config <CONFIG>]

# < 3.15
$ cd build
$ cmake -DCMAKE_INSTALL_PREFIX=/path/to/install -P cmake_install.cmake

指定编译类型

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# 1
$ cmake -DCMAKE_INSTALL_PREFIX:PATH=/path/to/install -DCMAKE_BUILD_TYPE=Release /path/to/src

# 2
$ cmake --config Release --build . --target install

语法

CMakeLists.txt 的语法比较简单，由命令、注释和空格组成。# 后面的是注释。

commond (args ...)

  • commond为命令名，大小写不敏感
  • args为参数
    • 如果包含空格，使用双引号

变量引用

变量引用用 ${VAR} 语法

命令

set

set命令将多变量放在一起。

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set (Foo a b c)
  • commond(${Foo}) 等价于 command(a b c)
  • commond("${Foo}") 等价于 command("a b c")

cmake_minimum_required

指定运行此配置文件所需的CMake的最低版本。

cmake_minimum_required (VERSION 2.8)

project

指定项目信息。

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project (Demo)

add_executable

指定生成目标。

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add_executable(Demo demo.cpp)

aux_source_directory

查找指定目录下的所有源文件，将结果存进指定变量名。

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aux_source_directory(<dir> <variable>)
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cmake_minimum_required (VERSION 2.8)
project (Demo)
aux_source_directory (. DIR_SRCS)
add_executable(Demo ${DIR_SRCS})

add_subdirectory

指明项目包含一个子目录，这样该目录下的CMakeLists.txt文件和源文件也会被处理。

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add_subdirectory(math)

指明可执行文件需要链接的库。

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target_link_libraries(Demo MathFunctions)

add_library

将指定的源文件生成链接文件，然后添加到工程中去

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aux_source_directory(. DIR_LIB_SRCS)
add_library(MathFunctions ${DIR_LIB_SRCS})

指定连接器查找库的文件夹。此命令的相对路径被解释为相对于当前源目录。

格式

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link_directories(directory1 directory2 ...)

示例

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link_directories(${PROJECT_BINARY_DIR}/third_party/googletest/)

include_directories

将给定的目录添加到编译器用来搜索头文件的目录中。相对路径被解释为相对于当前源目录。

格式

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include_directories([AFTER|BEFORE] [SYSTEM] dir1 [dir2 ...])

示例

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include_directories(${PROJECT_SOURCE_DIR}/third_party/glog/)
include_directories(${PROJECT_SOURCE_DIR}/third_party/hdfs/)

find_package_handle_standard_args

用于 find_package 的实现。

变量

Cache

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# CACHE, 不覆盖已有值. 
## 用途 
### 1. 在命令行指定变量, 且不被覆盖
set(MY_CACHE_VARIABLE "VALUE" CACHE STRING "Description")

# FORCE, 强制设置
set(MY_CACHE_VARIABLE "VALUE" CACHE STRING "" FORCE)

常用变量

  • PROJECT_BINARY_DIR
    • Full path to build directory for project.
  • PROJECT_SOURCE_DIR
    • Top level source directory for the current project.
  • CMAKE_CURRENT_SOURCE_DIR
    • This the full path to the source directory that is currently being processed by cmake.

Scope

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add_subdirectory : 建立新的 scope
include : 不会建立新的 scope
function : 建立新的 scope

示例

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bovenson@HP:~/Git/notes/C++/Code/CMake/test$ tree
.
├── CMakeLists.txt
└── t.cpp

0 directories, 2 files
bovenson@HP:~/Git/notes/C++/Code/CMake/test$ cat t.cpp 
#include <iostream>

using namespace std;

int main() {
    cout<<"Hello"<<endl;
    return 0;
}
bovenson@HP:~/Git/notes/C++/Code/CMake/test$ cat CMakeLists.txt 
project("test")
add_executable(Hello t.cpp)
bovenson@HP:~/Git/notes/C++/Code/CMake/test$ cmake .
-- The C compiler identification is GNU 5.4.0
-- The CXX compiler identification is GNU 5.4.0
-- 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: /home/bovenson/Git/notes/C++/Code/CMake/test
bovenson@HP:~/Git/notes/C++/Code/CMake/test$ tree
.
├── CMakeCache.txt
├── CMakeFiles
│   ├── 3.5.1
│   │   ├── CMakeCCompiler.cmake
│   │   ├── CMakeCXXCompiler.cmake
│   │   ├── CMakeDetermineCompilerABI_C.bin
│   │   ├── CMakeDetermineCompilerABI_CXX.bin
│   │   ├── CMakeSystem.cmake
│   │   ├── CompilerIdC
│   │   │   ├── a.out
│   │   │   └── CMakeCCompilerId.c
│   │   └── CompilerIdCXX
│   │       ├── a.out
│   │       └── CMakeCXXCompilerId.cpp
│   ├── cmake.check_cache
│   ├── CMakeDirectoryInformation.cmake
│   ├── CMakeOutput.log
│   ├── CMakeTmp
│   ├── feature_tests.bin
│   ├── feature_tests.c
│   ├── feature_tests.cxx
│   ├── Hello.dir
│   │   ├── build.make
│   │   ├── cmake_clean.cmake
│   │   ├── DependInfo.cmake
│   │   ├── depend.make
│   │   ├── flags.make
│   │   ├── link.txt
│   │   └── progress.make
│   ├── Makefile2
│   ├── Makefile.cmake
│   ├── progress.marks
│   └── TargetDirectories.txt
├── cmake_install.cmake
├── CMakeLists.txt
├── Makefile
└── t.cpp

6 directories, 31 files
bovenson@HP:~/Git/notes/C++/Code/CMake/test$ make
Scanning dependencies of target Hello
[ 50%] Building CXX object CMakeFiles/Hello.dir/t.cpp.o
[100%] Linking CXX executable Hello
[100%] Built target Hello
bovenson@HP:~/Git/notes/C++/Code/CMake/test$ tree
.
├── CMakeCache.txt
├── CMakeFiles
│   ├── 3.5.1
│   │   ├── CMakeCCompiler.cmake
│   │   ├── CMakeCXXCompiler.cmake
│   │   ├── CMakeDetermineCompilerABI_C.bin
│   │   ├── CMakeDetermineCompilerABI_CXX.bin
│   │   ├── CMakeSystem.cmake
│   │   ├── CompilerIdC
│   │   │   ├── a.out
│   │   │   └── CMakeCCompilerId.c
│   │   └── CompilerIdCXX
│   │       ├── a.out
│   │       └── CMakeCXXCompilerId.cpp
│   ├── cmake.check_cache
│   ├── CMakeDirectoryInformation.cmake
│   ├── CMakeOutput.log
│   ├── CMakeTmp
│   ├── feature_tests.bin
│   ├── feature_tests.c
│   ├── feature_tests.cxx
│   ├── Hello.dir
│   │   ├── build.make
│   │   ├── cmake_clean.cmake
│   │   ├── CXX.includecache
│   │   ├── DependInfo.cmake
│   │   ├── depend.internal
│   │   ├── depend.make
│   │   ├── flags.make
│   │   ├── link.txt
│   │   ├── progress.make
│   │   └── t.cpp.o
│   ├── Makefile2
│   ├── Makefile.cmake
│   ├── progress.marks
│   └── TargetDirectories.txt
├── cmake_install.cmake
├── CMakeLists.txt
├── Hello
├── Makefile
└── t.cpp

6 directories, 35 files
bovenson@HP:~/Git/notes/C++/Code/CMake/test$ ./Hello 
Hello

参考