Cmake series tutorial 1- initial cmake

What is? CMake

CMake It's a Cross platform Installation （ compile ） Tools , Can use simple 、 Unified statement to describe the installation or compilation process of all platforms . Can output the output of different compilers makefile or project file . 

CMake Use CMakeLists.txt As a project organization document ,CMake Not a cross platform compilation tool , It's a project building tool , Engineering projects can be generated on different platforms according to construction parameters , for example Windows Can be built under the platform  Visual Studio engineering   or  NMake engineering , Optional designation Visual Studio Version of ; stay Unix structure  Makefile engineering  .

CMake What can be done

• The project build
  • Building complex projects
  • Build cross platform projects
• project management
  • Large projects are interdependent
  • Project function extension adaptation
• unit testing
  • ctest
• Continuous construction
• Packaging releases
  • cpack

Why use CMake

• Source control   
  Organize a large number of project source code files by writing simple scripts , Dependency libraries, macro definitions, etc , Code files can be saved and named as needed , from CMakeLists.txt File organization code file relationship , In particular, cross project common module management .
• Unified settings for complex projects   
  CMake With hierarchical inheritance , Subfolder of CMakeLists.txt The file will automatically integrate the public properties set by the parent directory , All reference library directories that need unified management 、 Project property settings 、 Macro definitions, etc. only need to be at the top CMakeLists.txt Set in the file to share the settings .
• Build across platforms   
  Don't worry about Windows Use bat Complete the project build ,Unix Use shell As a build script , Just one set CMake Scripts are compatible with different platforms 、 compiler .
• Good scalability   
  CMake Scripts have programmable features , It has similar extensibility to scripting language , Developers can organize through simple programming and logic , Compatible with various complex environments and various construction parameters .
• Integration with third-party libraries   
  In normal projects, it is inevitable to reference mature third-party libraries ,CMake Allow by adding
• Continuous integration   
  CMake Support the command line method to call , A continuously integrated platform only needs to be installed and deployed CMake Environmental Science , The batch 、shell、python Wait for the script to execute simple commands to build the project and compile , Lay a good foundation for continuous integration .
• Open source project building tools   
  Many well-known cross platform open source projects use CMake As a source code building tool , for example ： cURL, OGRE, OpenCV, LLVM and Clang, Qt, ZeroMQ etc. .  The tools and code bases that God is using must be outstanding , Not to mention the common choice of many excellent open source works .

How to download and deploy CMake

Installation and deployment

visit  CMake Official website  , stay   The download page   Select the corresponding platform installation package , Download and install .

Windows

• Download installation package  
  stay Windows Installation under system CMake, Recommended download  *.msi  Format installation package , Search page , Search for keywords  win64-x64.msi  Download link for （cmake-3.15.0-rc2-win64-x64.msi）, Click to download .
• install  
  Double click to run the downloaded installation package , Follow the prompts of the installation tool to install to the specified directory of the computer .
• Installation successful  
  Start the command line prompt （CMD）, Input  cmake --version  confirm CMake Installation successful , And set the environment variables correctly , Successful installation will output installation CMake Version information for .C:\WINDOWS\system32>cmake –version 
  cmake version 3.15.0  CMake suite maintained and supported by Kitware (kitware.com/cmake).

Unix

• Download the source code  
  Search the page for  *.tar.gz  Suffix's compression package （cmake-3.15.0-rc2.tar.gz）, Click to download .
• Decompress the source code  
  stay Unix Extract and release the source code to the current directory in the environment , And switch to the source directory .tar xvf cmake-3.15.0-rc2.tar.gz 
  cd cmake-3.15.0-rc2
• Compile source code ./configure 
  make
  1. perform ./configure, Check the current environment , Determine the installed code base of the environment , Generate the configuration files required for the build , Prepare for code compilation .
  2. make Compiled source code .
• Source code installation sudo make install The installation needs to copy the files to the root directory , Corresponding file read and write permissions are required （sudo）.
• Installation successful  
  Start the terminal , Input  cmake --version  confirm CMake Installation successful , And set the environment variables correctly , Successful installation will output installation CMake Version information for .

MacOS

• Download installation package  
  choice  *.dmg  Download link for （cmake-3.15.0-rc2-Darwin-x86_64.dmg）, Click to download .
• install  
  Double-click on the run  cmake-3.15.0-rc2-Darwin-x86_64.dmg  Installation .
• Installation successful  
  Start the terminal , Input  cmake --version  confirm CMake Installation successful , And set the environment variables correctly , Successful installation will output installation CMake Version information for .

CMake Supported compilers

After successful installation , You can input  cmake -h  see CMake Parameter description of supported compilers and tools .

• Visual Studio（ Various versions ）
• NMake Makefiles
• Borland Makefiles
• Unix Makefiles
• CodeBlocks (MinGW/NMake/Unix Makefiles)
• CodeLite (MinGW/NMake/Unix Makefiles)
• Eclipse CDT4 (MinGW/NMake/Unix Makefiles)
• Kate (MinGW/NMake/Unix Makefiles)
• Sublime (MinGW/NMake/Unix Makefiles)

Learning path

1. Introductory tutorial . Learn a brief tutorial about CMake The basic use method .
2. CMake Variables and basic syntax . Practice Mastery CMake Variable declaration and common syntax use .
3. CMake Advanced Grammar . Use CMake Write macros and functions to realize flexible and extensible project settings .
4. Compilation options . Combine the compilation options of compilers on different platforms , Use CMake Set the variables and tools provided .

Learning resources

CMake A brief tutorial （ chinese ） 

CMake A brief tutorial （ english ） 

CMake Official documents v3.15

more CMake course ：Virbox Technology blogs