Question

环境：gcc（Ubuntu 4.8.4-2ubuntu1~14.04）4.8.4

我使用find_package( OpenCV REQUIRED )查找opencv库并使用target_link_libraries(executable ${OpenCV_LIBS})链接opencv。

我打开SET(CMAKE_VERBOSE_MAKEFILE 1)以便我可以看到编译器的命令是什么。

的CMakeLists.txt：

cmake_minimum_required (VERSION 2.8.3)
project (video_capture)

find_package( OpenCV REQUIRED )

SET(CMAKE_VERBOSE_MAKEFILE 1)

add_executable( vidcapture main.cpp)

target_link_libraries(vidcapture ${OpenCV_LIBS})

从编译器输出（link）可以看出，opencv库在-ldl -lm -lpthread -lrt -lGLU -lGL -lSM -lICE -lX11 -lXext -ltbb之后链接了两次。当-lrt需要放在编译器命令的末尾时，这似乎会产生问题，如下所述：link

如果我在编译器命令的末尾手动添加-lrt（即-lrt出现两次，一次出现在opencv lib之后，一次出现在opencv lib之后），它就无法工作。

问题：

为什么opencv被链接两次？
我应该如何克服这个问题，以便-lrt仅在编译器命令的末尾放置一次？

更新：

MESSAGE("${OpenCV_LIBS}")给了我： opencv_videostab;的 opencv_video ; opencv_ts; opencv_superres; opencv_stitching; opencv_photo; opencv_ocl; opencv_objdetect; opencv_nonfree; OPE ncv_ml; opencv_legacy; opencv_imgproc; opencv_highgui; opencv_gpu; opencv_flann; opencv_features2d; opencv_core; opencv_contrib; opencv_calib 3D

而编译器命令是：/usr/local/lib/libopencv_videostab.so.2.4.9 /usr/local/lib/libopencv_ts.a / usr / local / lib / libopencv_superres.so.2.4.9 /usr/local/lib/libopencv_stitching.so.2.4.9 /usr/local/lib/libopencv_contrib.so.2.4.9 -ldl -lm -lpthread -lrt -lGLU - lGL -lSM -lICE -lX11 -lXext -ltbb /usr/local/lib/libopencv_nonfree.so.2.4.9 /usr/local/lib/libopencv_ocl.so.2.4.9 /usr/local/lib/libopencv_gpu.so。 2.4.9 /usr/local/lib/libopencv_photo.so.2.4.9 /usr/local/lib/libopencv_objdetect.so.2.4.9 /usr/local/lib/libopencv_legacy.so.2.4.9 / usr /local/lib/libopencv_video.so.2.4.9 /usr/local/lib/libopencv_ml.so.2.4.9 /usr/local/lib/libopencv_calib3d.so.2.4.9 / usr / local / lib /libopencv_features2d.so.2.4.9 /usr/local/lib/libopencv_highgui.so.2.4.9 /usr/local/lib/libopencv_imgproc.so.2.4.9 /usr/local/lib/libopencv_flann.so.2.4.9 /usr/local/lib/libopencv_core.so.2.4.9 -Wl，-rpath，/ usr / local / lib

您可以看到opencv_video模块在${OpenCV_LIBS}中的opencv_ts模块之前列出，而在编译器命令中则是之后放置的。我想知道这是否是一些opencv自我依赖问题（例如opencv_video取决于应首先链接的opencv_videostab？

Answer 1

似乎CMake没有发送文件FindOpenCV.cmake，因此您使用3d party one来配置OpenCV库。

为什么opencv被链接两次？

可能OpenCV_LIBS实施并不完全正确。

我应该如何克服这个问题，以便-lrt只放在编译器命令的末尾一次？

在链接之前，只需将list(REMOVE_DUPLICATES OpenCV_LIBS) # duplicates are not needed anywhere list(REMOVE_ITEM OpenCV_LIBS "-lrt") # remove "rt" library from the list.. list(APPEND OpenCV_LIBS "-lrt") # ..and insert it to the end修改为您想要的一个：

USER

CMake链接opencv两次搞乱编译器命令顺序

1 个答案: