如何通过cmake用-fPIC编译jsoncpp

Posted 2023-02-22

【中文标题】如何通过cmake用-fPIC编译jsoncpp

【英文标题】：How to compile jsoncpp with -fPIC through cmake

【发布时间】：2015-03-02 13:35:42

【问题描述】：

我想编译jsoncpp 和-fPIC 到cmake。

在jsoncpp的网站上，它解释了正常编译的方式，如下所示。

mkdir -p build/debug
cd build/debug
cmake -DCMAKE_BUILD_TYPE=debug -DJSONCPP_LIB_BUILD_STATIC=ON -DJSONCPP_LIB_BUILD_SHARED=OFF -G "Unix Makefiles" ../..
make

如何在这一步中使用-fPIC 标志编译？

------------------------------------------ - - - - - - -编辑 - - - - - - - - - - - - - - - - - - -----------------------

我假设我必须在 -fPIC 的 makefile 中添加一些行。

所以我通过cmake添加了makefile的内容。

如何更改 -fPIC 标志的这个 makefile？

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【问题讨论】：

可能重复***.com/questions/18604301

【参考方案1】：

您必须更改 CMAKE_CXX_FLAGS 和 CMAKE_C_FLAGS 变量。您可以通过ccmake 或cmake-gui 进行操作（您必须切换高级），或者您可以照常提供：

cmake -DCMAKE_CXX_FLAGS=-fPIC -DCMAKE_C_FLAGS=-fPIC -DCMAKE_BUILD_TYPE=debug -DJSONCPP_LIB_BUILD_STATIC=ON -DJSONCPP_LIB_BUILD_SHARED=OFF -G "Unix Makefiles" ../..

不要费心更改Makefile，因为它会在您下次运行cmake 时被覆盖。

在CMake 2.8.9 中，您可以设置POSITION_INDEPENDENT_CODE 属性 在一个目标上使所有后续目标位置独立。或者你可以在CMakeLists.txt中设置全局变量

set(CMAKE_POSITION_INDEPENDENT_CODE ON)

或

cmake -DCMAKE_POSITION_INDEPENDENT_CODE=ON ..