Cmake构建工程设计——Cmake环境搭建

缺乏、安全感 2022-10-18 11:22 149阅读 0赞

Cmake为工程生成跨平台的工程构建工程，例如生成不同平台的Makefile或project文件，相比于Makefile，提供简单的语法功能。

# Cmake安装 #

进入官网下载Cmake版本：https://cmake.org/

## Windows ##

确保电脑安装有make和gcc。  
本次所使用的版本：

C:\Users\zx_work>make -v
    GNU Make 3.82.90
    Built for i686-pc-mingw32
    Copyright (C) 1988-2012 Free Software Foundation, Inc.
    License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
    This is free software: you are free to change and redistribute it.
    There is NO WARRANTY, to the extent permitted by law.
    
    C:\Users\zx_work>gcc -v
    Using built-in specs.
    COLLECT_GCC=gcc
    COLLECT_LTO_WRAPPER=f:/tools/mingw/bin/../libexec/gcc/mingw32/9.2.0/lto-wrapper.exe
    Target: mingw32
    Configured with: ../src/gcc-9.2.0/configure --build=x86_64-pc-linux-gnu --host=mingw32 --target=mingw32 --disable-win32-registry --with-arch=i586 --with-tune=generic --enable-static --enable-shared --enable-threads --enable-languages=c,c++,objc,obj-c++,fortran,ada --with-dwarf2 --disable-sjlj-exceptions --enable-version-specific-runtime-libs --enable-libgomp --disable-libvtv --with-libiconv-prefix=/mingw --with-libintl-prefix=/mingw --enable-libstdcxx-debug --disable-build-format-warnings --prefix=/mingw --with-gmp=/mingw --with-mpfr=/mingw --with-mpc=/mingw --with-isl=/mingw --enable-nls --with-pkgversion='MinGW.org GCC Build-2'
    Thread model: win32
    gcc version 9.2.0 (MinGW.org GCC Build-2)
    
    C:\Users\zx_work>g++ -v
    Using built-in specs.
    COLLECT_GCC=g++
    COLLECT_LTO_WRAPPER=f:/tools/mingw/bin/../libexec/gcc/mingw32/9.2.0/lto-wrapper.exe
    Target: mingw32
    Configured with: ../src/gcc-9.2.0/configure --build=x86_64-pc-linux-gnu --host=mingw32 --target=mingw32 --disable-win32-registry --with-arch=i586 --with-tune=generic --enable-static --enable-shared --enable-threads --enable-languages=c,c++,objc,obj-c++,fortran,ada --with-dwarf2 --disable-sjlj-exceptions --enable-version-specific-runtime-libs --enable-libgomp --disable-libvtv --with-libiconv-prefix=/mingw --with-libintl-prefix=/mingw --enable-libstdcxx-debug --disable-build-format-warnings --prefix=/mingw --with-gmp=/mingw --with-mpfr=/mingw --with-mpc=/mingw --with-isl=/mingw --enable-nls --with-pkgversion='MinGW.org GCC Build-2'
    Thread model: win32
    gcc version 9.2.0 (MinGW.org GCC Build-2)

本次所使用的Cmake版本为3.15.5

C:\Users\zx_work>cmake --version
    cmake version 3.15.5

**不同的版本对语法解析有差异。**

## Linux ##

推荐到官网下载源码安装，确保与Windows的保持一致  
Linux所使用的版本：

ghost@ghost-machine:~/test_Makefile$ make -v
    GNU Make 4.1
    为 x86_64-pc-linux-gnu 编译
    Copyright (C) 1988-2014 Free Software Foundation, Inc.
    许可证：GPLv3+：GNU 通用公共许可证第 3 版或更新版本<http://gnu.org/licenses/gpl.html>。
    本软件是自由软件：您可以自由修改和重新发布它。
    在法律允许的范围内没有其他保证。
    ghost@ghost-machine:~/test_Makefile$ gcc -v
    Using built-in specs.
    COLLECT_GCC=gcc
    COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/7/lto-wrapper
    OFFLOAD_TARGET_NAMES=nvptx-none
    OFFLOAD_TARGET_DEFAULT=1
    Target: x86_64-linux-gnu
    Configured with: ../src/configure -v --with-pkgversion='Ubuntu 7.5.0-3ubuntu1~18.04' --with-bugurl=file:///usr/share/doc/gcc-7/README.Bugs --enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++ --prefix=/usr --with-gcc-major-version-only --program-suffix=-7 --program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-libmpx --enable-plugin --enable-default-pie --with-system-zlib --with-target-system-zlib --enable-objc-gc=auto --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
    Thread model: posix
    gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04) 
    ghost@ghost-machine:~/test_Makefile$ g++ -v
    Using built-in specs.
    COLLECT_GCC=g++
    COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/7/lto-wrapper
    OFFLOAD_TARGET_NAMES=nvptx-none
    OFFLOAD_TARGET_DEFAULT=1
    Target: x86_64-linux-gnu
    Configured with: ../src/configure -v --with-pkgversion='Ubuntu 7.5.0-3ubuntu1~18.04' --with-bugurl=file:///usr/share/doc/gcc-7/README.Bugs --enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++ --prefix=/usr --with-gcc-major-version-only --program-suffix=-7 --program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-libmpx --enable-plugin --enable-default-pie --with-system-zlib --with-target-system-zlib --enable-objc-gc=auto --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
    Thread model: posix
    gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04)

# Cmake工程文件 #

Cmake依赖文件CMakeLists.txt和Makefile文件一样，用于构建工程。同时有着配置文件\*.cmake用于跨平台或交叉编译的配置。  
CMakeLists.txt示例

cmake_minimum_required(VERSION 3.15.5)
    
    set(PROJECT_TARGET project)
    project(${PROJECT_TARGET})

\*.cmake示例  
config.cmake

set(CMAKE_C_COMPILER "gcc")
    set(CMAKE_CXX_COMPILER "g++")
    
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
    
    set(LIBRARY_OUTPUT_PATH ${PROJECT_SOURCE_DIR}/target/libs)
    set(EXECUTABLE_OUTPUT_PATH ${PROJECT_SOURCE_DIR}/target)

# Cmake构建编译 #

cmake <CMakeLists.txt所在路径>
    make & make install

由于Cmake会在当前路径下创建编译的Makefile以及编译文件，因此创建一个build文件夹来放置缓存文件，通常通过脚本进行构建。  
其中也可以用Cmake命令代替，效果一样

只编译  
等同于make

cmake <CMakeLists.txt所在路径>
    cmake --build .

编译并安装  
等同于make & make install

cmake <CMakeLists.txt所在路径>
    cmake --build . --target install

# Cmake打印输出message #

Cmake在构建过程中需要输出信息，可使用message进行输出  
输出分等级  
message(\[output level\] “log information”)

无					：重要消息
    STATUS				：非重要消息
    WARNING				：警告信息，但Cmake会继续执行
    AUTHOR_WARNING		：警告信息（针对开发人员警告），但Cmake会继续执行
    SEND_ERROR			：错误，Cmake会继续执行处理，但不会生成Makefile
    FATAL_ERROR			：错误，Cmake会立即停止执行，不生成Makefile

测试输出

message("Cmake none message")
    message(STATUS "Cmake STATUS message")
    message(WARNING "Cmake WARNING message")
    message(AUTHOR_WARNING "Cmake AUTHOR_WARNING message")
    message(SEND_ERROR "Cmake SEND_ERROR message")
    message("Cmake end message")

执行结果

Cmake none message
    -- Cmake STATUS message
    CMake Warning at CMakeLists.txt:23 (message):
      Cmake WARNING message
    
    
    CMake Warning (dev) at CMakeLists.txt:24 (message):
      Cmake AUTHOR_WARNING message
    This warning is for project developers.  Use -Wno-dev to suppress it.
    
    CMake Error at CMakeLists.txt:25 (message):
      Cmake SEND_ERROR message
    
    
    Cmake end message
    PC Windows Debug
    using gcc
    -- Configuring incomplete, errors occurred!
    See also "G:/project/project_cache/CMakeFiles/CMakeOutput.log".
    camke filed

由于有SEND\_ERROR打印等级，CmakeList能够继续解析，但无法生成Makefile文件进行编译

测试输出

执行结果

Cmake none message
    -- Cmake STATUS message
    CMake Warning at CMakeLists.txt:23 (message):
      Cmake WARNING message
    
    
    CMake Warning (dev) at CMakeLists.txt:24 (message):
      Cmake AUTHOR_WARNING message
    This warning is for project developers.  Use -Wno-dev to suppress it.
    
    CMake Error at CMakeLists.txt:25 (message):
      Cmake SEND_ERROR message
    
    
    CMake Error at CMakeLists.txt:26 (message):
      Cmake FATAL_ERROR message
    
    
    -- Configuring incomplete, errors occurred!
    See also "G:/project/project_cache/CMakeFiles/CMakeOutput.log".
    camke filed

由于有FATAL\_ERROR打印等级，CmakeList立即中断执行并退出。

# Cmake默认变量 #

通过message在构建过程中打印类似于shell脚本的echo

message("PROJECT_SOURCE_DIR ${PROJECT_SOURCE_DIR}")
    message("PROJECT_BINARY_DIR ${PROJECT_BINARY_DIR}")
    message("CMAKE_CURRENT_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}")
    message("CMAKE_CURRENT_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}")
    
    message("CMAKE_COMPILER_IS_GNUCXX ${CMAKE_COMPILER_IS_GNUCXX}")
    message("CMAKE_SYSTEM_NAME ${CMAKE_SYSTEM_NAME}")
    
    message("CMAKE_TOOLCHAIN_FILE ${CMAKE_TOOLCHAIN_FILE}")
    message("LIBRARY_OUTPUT_PATH ${LIBRARY_OUTPUT_PATH}")
    message("EXECUTABLE_OUTPUT_PATH ${EXECUTABLE_OUTPUT_PATH}")
    
    if(WIN32)
    	message("PC Windows ${CMAKE_BUILD_TYPE}")
    elseif(UNIX)
    	message("PC UNIX ${CMAKE_BUILD_TYPE}")
    	add_definitions(-D USE_LINUX)	
    endif(WIN32)

变量说明

PROJECT_SOURCE_DIR：工程路径，执行cmake时加载的CMakeLists.txt所对应的路径
    PROJECT_BINARY_DIR：构建工程的路径，执行cmake时当前的路径，用于放置缓存
    CMAKE_CURRENT_SOURCE_DIR：当前CMakeLists.txt所在路径，不同的CMakeLists.txt对应的路径不同
    CMAKE_CURRENT_BINARY_DIR：当前CMakeLists.txt所对应的缓存路径，不同的CMakeLists.txt对应的路径不同
    CMAKE_COMPILER_IS_GNUCXX：是否是GNU的编译器
    CMAKE_SYSTEM_NAME：当前编译环境的系统名

在Windows与Linux下有着不同的打印  
Windows

PROJECT_SOURCE_DIR G:/share/Code/test_Makefile
    PROJECT_BINARY_DIR G:/share/Code/test_Makefile/project_cache
    CMAKE_CURRENT_SOURCE_DIR G:/share/Code/test_Makefile
    CMAKE_CURRENT_BINARY_DIR G:/share/Code/test_Makefile/project_cache
    CMAKE_COMPILER_IS_GNUCXX 1
    CMAKE_SYSTEM_NAME Windows

Linux

PROJECT_SOURCE_DIR /home/ghost/test_Makefile
    PROJECT_BINARY_DIR /home/ghost/test_Makefile/project_cache
    CMAKE_CURRENT_SOURCE_DIR /home/ghost/test_Makefile
    CMAKE_CURRENT_BINARY_DIR /home/ghost/test_Makefile/project_cache
    CMAKE_COMPILER_IS_GNUCXX 1
    CMAKE_SYSTEM_NAME Linux

# Cmake限制的最低版本 #

不同的Cmake版本对语法解析有差异，因此需要限定最低的Cmake版本。低于该版本的不能执行。本次限制的最低版本为3.15.5

cmake_minimum_required(VERSION 3.15.5)