Ubuntu系统下交叉编译cJSON

一、参考资料

二、准备工作

1. 编译环境

• 宿主机：Ubuntu 20.04.6 LTS
• Host：ARM32位
• 交叉编译器：arm-linux-gnueabihf-gcc-11.1.0

2. 设置交叉编译工具链

在交叉编译之前，需要设置交叉编译工具链的环境变量。

export PATH=/path/to/toolchains/arm-linux-gnueabihf/bin:$PATH

三、交叉编译cJSON

1. 下载源码

GitHub - DaveGamble/cJSON: Ultralightweight JSON parser in ANSI C

下载并解压源码。

tar -xvzf cJSON-1.7.18.tar.gz

2. 编译安装

cd cJSON-1.7.18
mkdir build && cd build

cmake -DCMAKE_INSTALL_PREFIX=/path/to/cjson/arm_install \
	  -DCMAKE_C_COMPILER=arm-linux-gnueabihf-gcc \
      -DCMAKE_CXX_COMPILER=arm-linux-gnueabihf-g++ \
      -DBUILD_SHARED_LIBS=ON \
      -DENABLE_CJSON_TEST=OFF ..  # 关闭测试程序
      
make -j8
make install 

编译安装之后的文件目录：

yoyo@yoyo:~/360Downloads/cJSON-1.7.18$ tree -L 3 arm_install/
arm_install/
├── include
│   └── cjson
│       └── cJSON.h
└── lib
    ├── cmake
    │   └── cJSON
    ├── libcjson.so -> libcjson.so.1
    ├── libcjson.so.1 -> libcjson.so.1.7.18
    ├── libcjson.so.1.7.18
    └── pkgconfig
        └── libcjson.pc

cmake编译：

yoyo@yoyo:~/360Downloads/cJSON-1.7.18/build$ cmake -DCMAKE_INSTALL_PREFIX=/path/to/cJSON-1.7.18/arm_install \
>   -DCMAKE_C_COMPILER=arm-linux-gnueabihf-gcc \
>       -DCMAKE_CXX_COMPILER=arm-linux-gnueabihf-g++ \
>       -DBUILD_SHARED_LIBS=ON \
>       -DENABLE_CJSON_TEST=OFF ..
CMake Deprecation Warning at CMakeLists.txt:2 (cmake_minimum_required):
  Compatibility with CMake < 3.10 will be removed from a future version of
  CMake.

  Update the VERSION argument <min> value.  Or, use the <min>...<max> syntax
  to tell CMake that the project requires at least <min> but has been updated
  to work with policies introduced by <max> or earlier.


-- The C compiler identification is GNU 11.1.0
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /path/to/toolchains/arm-linux-gnueabihf/bin/arm-linux-gnueabihf-gcc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Performing Test FLAG_SUPPORTED_stdc89
-- Performing Test FLAG_SUPPORTED_stdc89 - Success
-- Performing Test FLAG_SUPPORTED_pedantic
-- Performing Test FLAG_SUPPORTED_pedantic - Success
-- Performing Test FLAG_SUPPORTED_Wall
-- Performing Test FLAG_SUPPORTED_Wall - Success
-- Performing Test FLAG_SUPPORTED_Wextra
-- Performing Test FLAG_SUPPORTED_Wextra - Success
-- Performing Test FLAG_SUPPORTED_Werror
-- Performing Test FLAG_SUPPORTED_Werror - Success
-- Performing Test FLAG_SUPPORTED_Wstrictprototypes
-- Performing Test FLAG_SUPPORTED_Wstrictprototypes - Success
-- Performing Test FLAG_SUPPORTED_Wwritestrings
-- Performing Test FLAG_SUPPORTED_Wwritestrings - Success
-- Performing Test FLAG_SUPPORTED_Wshadow
-- Performing Test FLAG_SUPPORTED_Wshadow - Success
-- Performing Test FLAG_SUPPORTED_Winitself
-- Performing Test FLAG_SUPPORTED_Winitself - Success
-- Performing Test FLAG_SUPPORTED_Wcastalign
-- Performing Test FLAG_SUPPORTED_Wcastalign - Success
-- Performing Test FLAG_SUPPORTED_Wformat2
-- Performing Test FLAG_SUPPORTED_Wformat2 - Success
-- Performing Test FLAG_SUPPORTED_Wmissingprototypes
-- Performing Test FLAG_SUPPORTED_Wmissingprototypes - Success
-- Performing Test FLAG_SUPPORTED_Wstrictoverflow2
-- Performing Test FLAG_SUPPORTED_Wstrictoverflow2 - Success
-- Performing Test FLAG_SUPPORTED_Wcastqual
-- Performing Test FLAG_SUPPORTED_Wcastqual - Success
-- Performing Test FLAG_SUPPORTED_Wundef
-- Performing Test FLAG_SUPPORTED_Wundef - Success
-- Performing Test FLAG_SUPPORTED_Wswitchdefault
-- Performing Test FLAG_SUPPORTED_Wswitchdefault - Success
-- Performing Test FLAG_SUPPORTED_Wconversion
-- Performing Test FLAG_SUPPORTED_Wconversion - Success
-- Performing Test FLAG_SUPPORTED_Wccompat
-- Performing Test FLAG_SUPPORTED_Wccompat - Success
-- Performing Test FLAG_SUPPORTED_fstackprotectorstrong
-- Performing Test FLAG_SUPPORTED_fstackprotectorstrong - Success
-- Performing Test FLAG_SUPPORTED_Wcomma
-- Performing Test FLAG_SUPPORTED_Wcomma - Failed
-- Performing Test FLAG_SUPPORTED_Wdoublepromotion
-- Performing Test FLAG_SUPPORTED_Wdoublepromotion - Success
-- Performing Test FLAG_SUPPORTED_Wparentheses
-- Performing Test FLAG_SUPPORTED_Wparentheses - Success
-- Performing Test FLAG_SUPPORTED_Wformatoverflow
-- Performing Test FLAG_SUPPORTED_Wformatoverflow - Success
-- Performing Test FLAG_SUPPORTED_Wunusedmacros
-- Performing Test FLAG_SUPPORTED_Wunusedmacros - Success
-- Performing Test FLAG_SUPPORTED_Wmissingvariabledeclarations
-- Performing Test FLAG_SUPPORTED_Wmissingvariabledeclarations - Failed
-- Performing Test FLAG_SUPPORTED_Wusedbutmarkedunused
-- Performing Test FLAG_SUPPORTED_Wusedbutmarkedunused - Failed
-- Performing Test FLAG_SUPPORTED_Wswitchenum
-- Performing Test FLAG_SUPPORTED_Wswitchenum - Success
-- Performing Test FLAG_SUPPORTED_fvisibilityhidden
-- Performing Test FLAG_SUPPORTED_fvisibilityhidden - Success
-- Configuring done (1.5s)
-- Generating done (0.0s)
CMake Warning:
  Manually-specified variables were not used by the project:

    CMAKE_CXX_COMPILER


-- Build files have been written to: /path/to/cJSON-1.7.18/build

make编译：

yoyo@yoyo:~/360Downloads/cJSON-1.7.18/build$ make -j8
[ 50%] Building C object CMakeFiles/cjson.dir/cJSON.c.o
[100%] Linking C shared library libcjson.so
[100%] Built target cjson

make install 安装：

yoyo@yoyo:~/360Downloads/cJSON-1.7.18/build$ make install 
[100%] Built target cjson
Install the project...
-- Install configuration: ""
-- Installing: /path/to/cJSON-1.7.18/arm_install/include/cjson/cJSON.h
-- Installing: /path/to/cJSON-1.7.18/arm_install/lib/pkgconfig/libcjson.pc
-- Installing: /path/to/cJSON-1.7.18/arm_install/lib/libcjson.so.1.7.18
-- Installing: /path/to/cJSON-1.7.18/arm_install/lib/libcjson.so.1
-- Installing: /path/to/cJSON-1.7.18/arm_install/lib/libcjson.so
-- Installing: /path/to/cJSON-1.7.18/arm_install/lib/cmake/cJSON/cjson.cmake
-- Installing: /path/to/cJSON-1.7.18/arm_install/lib/cmake/cJSON/cjson-noconfig.cmake
-- Installing: /path/to/cJSON-1.7.18/arm_install/lib/cmake/cJSON/cJSONConfig.cmake
-- Installing: /path/to/cJSON-1.7.18/arm_install/lib/cmake/cJSON/cJSONConfigVersion.cmake

3. 移植到开发板

cp -arf /path/to/cJSON/arm_install/lib/ /usr/cJSON/