包含静态库

包含静态库#

演示如何创建并链接静态库的hello world示例。该示例将库文件和可执行文件放在同一目录，实际项目中建议使用子项目结构。

项目文件结构：

. 
├── CMakeLists.txt
├── include
│   └── static
│       └── Hello.h
└── src
    ├── Hello.cpp
    └── main.cpp

关键文件：

  • CMakeLists.txt: 包含CMake构建指令

  • include/static/Hello.h: 头文件

  • src/Hello.cpp: 库源文件

  • src/main.cpp: 主程序文件

核心概念#

创建静态库#

使用add_library命令创建静态库：

add_library(hello_library STATIC
    src/Hello.cpp
)

这会生成libhello_library.a静态库文件。现代CMake推荐直接指定源文件路径。

包含目录配置#

使用target_include_directories设置公共包含目录：

target_include_directories(hello_library
    PUBLIC
        ${PROJECT_SOURCE_DIR}/include
)

作用域说明：

  • PRIVATE: 仅当前目标使用

  • INTERFACE: 仅链接本库的目标使用

  • PUBLIC: 同时适用于当前目标和链接目标

最佳实践：建议采用命名空间目录结构（如include/static/），源文件包含时使用：

#include "static/Hello.h"

链接库文件#

使用target_link_libraries链接库到可执行文件：

add_executable(hello_binary
    src/main.cpp
)

target_link_libraries(hello_binary
    PRIVATE
        hello_library
)

这会自动传播PUBLIC/INTERFACE包含目录。编译器实际执行的链接命令示例：

/usr/bin/c++ CMakeFiles/hello_binary.dir/src/main.cpp.o -o hello_binary -rdynamic libhello_library.a

构建流程#

$ mkdir build

$ cd build

$ cmake ..
-- The C compiler identification is GNU 4.8.4
-- The CXX compiler identification is GNU 4.8.4
-- 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
-- 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
-- Configuring done
-- Generating done
-- Build files have been written to: /home/matrim/workspace/cmake-examples/01-basic/C-static-library/build

$ make
Scanning dependencies of target hello_library
[ 50%] Building CXX object CMakeFiles/hello_library.dir/src/Hello.cpp.o
Linking CXX static library libhello_library.a
[ 50%] Built target hello_library
Scanning dependencies of target hello_binary
[100%] Building CXX object CMakeFiles/hello_binary.dir/src/main.cpp.o
Linking CXX executable hello_binary
[100%] Built target hello_binary

$ ls
CMakeCache.txt  CMakeFiles  cmake_install.cmake  hello_binary  libhello_library.a  Makefile

$ ./hello_binary
Hello Static Library!
目录