![](/img/trans.png)
[英]How to debug linker errors? Getting undefined reference errors when statically linking ICU
[英]Linker/loader errors "undefined reference to ..." when linking with raspicam library
我正在尝试使用cmake编译一个简单的项目,同时使用 raspicam 库。 项目编译无误; 然而,我在结束LD错误。 Raspicam 从这里下载: http ://www.uco.es/investiga/grupos/ava/node/40。 有任何想法吗?
主.cpp:
#include <raspicam_cv.h>
int main ( int argc,char **argv ) {
raspicam::RaspiCam_Cv capture;
if (!capture.open()) {
return 1;
}
return 0;
}
CMakeLists.txt:
cmake_minimum_required(VERSION 3.10)
project(raspicam)
set(CMAKE_CXX_STANDARD 17)
include_directories(raspicam-0.1.6/src)
link_directories(raspicam-0.1.6/src)
add_executable(raspicam main.cpp)
set(RASPICAM_LIB ${CMAKE_SHARED_LIBRARY_PREFIX}raspicam_cv${CMAKE_SHARED_LIBRARY_SUFFIX})
target_link_libraries(raspicam ${RASPICAM_LIB})
构建命令:
cd raspicam-0.1.6/ && cmake -DOpenCV_DIR=/home/user/Projects/opencv/opencv-build . && make && cd .. && cmake . && make
错误:
CMakeFiles/raspicam.dir/main.cpp.o: In function `main':
/home/user/CLionProjects/raspicam/main.cpp:5: undefined reference to `raspicam::RaspiCam_Cv::RaspiCam_Cv()'
/home/user/CLionProjects/raspicam/main.cpp:7: undefined reference to `raspicam::RaspiCam_Cv::open()'
/home/user/CLionProjects/raspicam/main.cpp:5: undefined reference to `raspicam::RaspiCam_Cv::~RaspiCam_Cv()'
/home/user/CLionProjects/raspicam/main.cpp:5: undefined reference to `raspicam::RaspiCam_Cv::~RaspiCam_Cv()'
collect2: error: ld returned 1 exit status
CMakeFiles/raspicam.dir/build.make:94: recipe for target 'raspicam' failed
make[2]: *** [raspicam] Error 1
CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/raspicam.dir/all' failed
make[1]: *** [CMakeFiles/raspicam.dir/all] Error 2
Makefile:83: recipe for target 'all' failed
make: *** [all] Error 2
看来您正在尝试从源代码构建 raspicam。 查看您链接的文档,似乎 raspicam 提供了一个 CMake 查找包,并鼓励用户像这样包含该库:
project (my_raspi_project)
find_package(raspicam REQUIRED)
add_executable (my_raspi_project main.cpp)
target_link_libraries (my_raspi_project ${raspicam_LIBS})
我鼓励您这样做,但这需要在您的系统上安装 raspicam。 也就是说,您首先需要按照上述文档中列出的安装步骤进行操作:
tar xvzf raspicamxx.tgz
cd raspicamxx
mkdir build
cd build
cmake ..
make
sudo make install
sudo ldconfig
这会将包安装在 CMake 可以找到它的位置,并允许 CMakeList.txt 中使用的find_package(raspicam REQUIRED)
正常工作。
如果您无法将库安装到您的开发机器上,而是想从源代码与您的项目一起构建它,您可以考虑:
使用 CMake 的add_subdirectory命令
使用 CMake 的ExternalProject_Add命令。
选项 #1 将允许您更新 CMakeList.txt 文件,如下所示:
cmake_minimum_required(VERSION 3.10)
project(raspicam)
set(CMAKE_CXX_STANDARD 17)
add_subdirectory(<path to raspicam CMakeList.txt>)
add_executable(my_raspicam_program main.cpp)
target_link_libraries(my_raspicam_program raspicam)
请注意,您需要将目标名称raspicam
更改为唯一的名称,因为该目标名称由包含在 add_subdirectory 中的包使用。
选项#2 更复杂,但有一个额外的好处,即您不会在版本控制系统中跟踪 raspicam 源代码。
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.