一、介绍

如先前在第三方库中所述，较新版本的 CMake 允许您使用导入的 ALIAS imported 目标链接第三方库。

本教程中的文件树如下:

$ tree
.
├── CMakeLists.txt
├── main.cpp

• CMakeLists.txt：CMake 指令
• main.cpp：源文件

二、环境版本

• CMake v3.5+
• 安装在默认位置的 boost 库

解析

导入目标

Imported targets 是 FindXXX 模块导出的只读目标。

在 CMake 命令中包含 boost 这个库：

  target_link_libraries( imported_targets
      PRIVATE
          Boost::filesystem
  )

作用是自动链接 Boost::filesystem 和 Boost :: system 库，同时还包括 Boost 头文件目录。

三、编译例子

$ mkdir build
$ cd build/
$ 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
-- Boost version: 1.58.0
-- Found the following Boost libraries:
--   filesystem
--   system
boost found
-- Configuring done
-- Generating done
-- Build files have been written to: /data/code/01-basic/K-imported-targets/build
$ make
Scanning dependencies of target imported_targets
[ 50%] Building CXX object CMakeFiles/imported_targets.dir/main.cpp.o
[100%] Linking CXX executable imported_targets
[100%] Built target imported_targets
$ ./imported_targets
Hello Third Party Include!
Path is not relative