I'm running RHEL 5.1 and use gcc.
How I tell cmake to add -pthread to compilation and linking?
#Manuel was part way there. You can add the compiler option as well, like this:
If you have CMake 3.1.0+, this becomes even easier:
set(THREADS_PREFER_PTHREAD_FLAG ON)
find_package(Threads REQUIRED)
target_link_libraries(my_app PRIVATE Threads::Threads)
If you are using CMake 2.8.12+, you can simplify this to:
find_package(Threads REQUIRED)
if(THREADS_HAVE_PTHREAD_ARG)
target_compile_options(my_app PUBLIC "-pthread")
endif()
if(CMAKE_THREAD_LIBS_INIT)
target_link_libraries(my_app "${CMAKE_THREAD_LIBS_INIT}")
endif()
Older CMake versions may require:
find_package(Threads REQUIRED)
if(THREADS_HAVE_PTHREAD_ARG)
set_property(TARGET my_app PROPERTY COMPILE_OPTIONS "-pthread")
set_property(TARGET my_app PROPERTY INTERFACE_COMPILE_OPTIONS "-pthread")
endif()
if(CMAKE_THREAD_LIBS_INIT)
target_link_libraries(my_app "${CMAKE_THREAD_LIBS_INIT}")
endif()
If you want to use one of the first two methods with CMake 3.1+, you will need set(THREADS_PREFER_PTHREAD_FLAG ON) there too.
The following should be clean (using find_package) and work (the find module is called FindThreads):
cmake_minimum_required (VERSION 2.6)
find_package (Threads)
add_executable (myapp main.cpp ...)
target_link_libraries (myapp ${CMAKE_THREAD_LIBS_INIT})
Here is the right anwser:
ADD_EXECUTABLE(your_executable ${source_files})
TARGET_LINK_LIBRARIES( your_executable
pthread
)
equivalent to
-lpthread
target_compile_options solution above is wrong, it won't link the library.
Use:
SET(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -pthread")
OR
target_link_libraries(XXX PUBLIC pthread)
OR
set_target_properties(XXX PROPERTIES LINK_LIBRARIES -pthread)
Related
I am implementing CMake in my code but I'm getting the error
"Cannot specify link libraries for target "Qt5::Widgets" which is not built by the project".
Below are the contents of the CMakeLists.txt:
#Specify the version being used aswell as the language
cmake_minimum_required(VERSION 2.6)
#Name your project here
project(eCAD)
#Sends the -std=c++11 flag to the gcc compiler
ADD_DEFINITIONS(-std=c++11)
#This tells CMake to main.cpp and name it eCAD
add_executable(eCAD main.cpp)
#include the subdirectory containing our libs
add_subdirectory (gui)
include_directories(gui)
#include Qt directories
find_package(Qt5Widgets)
find_package(Qt5Core)
find_package(Qt5Designer)
SET(QT_USE_QTDESIGNER ON)
#link_libraries
target_link_libraries(Qt5::Widgets Qt5::Core)
In addition to the accepted answer: An important detail is to place target_link_libraries after the add_executable and find_package lines, so all linked components are known.
The first argument of target_link_libraries is the target name:
target_link_libraries(eCAD Qt5::Widgets Qt5::Core)
Also, do not confuse target name with the project name:
a command project specifies a project name, but
a target is the one created with add_executable, add_library or add_custom_target.
The error message is about the target.
Set you_lib_name before setting target_link_libraries
set(you_lib_name libname)
target_link_libraries(you_lib_name Qt5::Widgets Qt5::Core)
I asked a similar question about linking a project with OpenCV a few days ago. I got that working, but now I've hit a very weird problem using CMake and adding LibTorch to the project.
If I only use OpenCV in the project, everything compiles, links, and runs fine.
But if I add Torch to CMakeLists.txt, I get a linker error:
cmake_minimum_required(VERSION 3.0 FATAL_ERROR)
set(CMAKE_VERBOSE_MAKEFILE ON)
project(torchscriptie)
find_package( OpenCV REQUIRED )
include_directories( ${OpenCV_INCLUDE_DIRS} )
find_package(Torch HINTS "/usr/local/libtorch")
message(STATUS "TORCH_LIBRARIES = ${TORCH_LIBRARIES}")
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${TORCH_CXX_FLAGS}")
add_executable(torchscriptie main.cpp)
target_link_libraries( torchscriptie ${OpenCV_LIBS} )
target_link_libraries(torchscriptie "${TORCH_LIBRARIES}")
set_property(TARGET torchscriptie PROPERTY CXX_STANDARD 14)
This CMakeLists.txt file causes this error:
CMakeFiles/torchscriptie.dir/main.cpp.o: In function `main':
/code/cpp/torchscriptie/main.cpp:18: undefined reference to `cv::imread(std::string const&, int)'
/code/cpp/torchscriptie/main.cpp:24: undefined reference to `cv::namedWindow(std::string const&, int)'
/code/cpp/torchscriptie/main.cpp:25: undefined reference to `cv::imshow(std::string const&, cv::_InputArray const&)'
collect2: error: ld returned 1 exit status
Here's the command:
/usr/bin/c++ -g -rdynamic CMakeFiles/torchscriptie.dir/main.cpp.o -o torchscriptie -Wl,-rpath,/usr/local/lib:/usr/local/libtorch/lib /usr/local/lib/libopencv_gapi.so.4.3.0 /usr/local/lib/libopencv_stitching.so.4.3.0 /usr/local/lib/libopencv_alphamat.so.4.3.0 /usr/local/lib/libopencv_aruco.so.4.3.0 /usr/local/lib/libopencv_bgsegm.so.4.3.0 /usr/local/lib/libopencv_bioinspired.so.4.3.0 /usr/local/lib/libopencv_ccalib.so.4.3.0 /usr/local/lib/libopencv_dnn_objdetect.so.4.3.0 /usr/local/lib/libopencv_dnn_superres.so.4.3.0 /usr/local/lib/libopencv_dpm.so.4.3.0 /usr/local/lib/libopencv_face.so.4.3.0 /usr/local/lib/libopencv_freetype.so.4.3.0 /usr/local/lib/libopencv_fuzzy.so.4.3.0 /usr/local/lib/libopencv_hdf.so.4.3.0 /usr/local/lib/libopencv_hfs.so.4.3.0 /usr/local/lib/libopencv_img_hash.so.4.3.0 /usr/local/lib/libopencv_intensity_transform.so.4.3.0 /usr/local/lib/libopencv_line_descriptor.so.4.3.0 /usr/local/lib/libopencv_quality.so.4.3.0 /usr/local/lib/libopencv_rapid.so.4.3.0 /usr/local/lib/libopencv_reg.so.4.3.0 /usr/local/lib/libopencv_rgbd.so.4.3.0 /usr/local/lib/libopencv_saliency.so.4.3.0 /usr/local/lib/libopencv_stereo.so.4.3.0 /usr/local/lib/libopencv_structured_light.so.4.3.0 /usr/local/lib/libopencv_superres.so.4.3.0 /usr/local/lib/libopencv_surface_matching.so.4.3.0 /usr/local/lib/libopencv_tracking.so.4.3.0 /usr/local/lib/libopencv_videostab.so.4.3.0 /usr/local/lib/libopencv_viz.so.4.3.0 /usr/local/lib/libopencv_xfeatures2d.so.4.3.0 /usr/local/lib/libopencv_xobjdetect.so.4.3.0 /usr/local/lib/libopencv_xphoto.so.4.3.0 /usr/local/libtorch/lib/libtorch.so /usr/local/libtorch/lib/libc10.so /usr/local/lib/libopencv_shape.so.4.3.0 /usr/local/lib/libopencv_highgui.so.4.3.0 /usr/local/lib/libopencv_datasets.so.4.3.0 /usr/local/lib/libopencv_plot.so.4.3.0 /usr/local/lib/libopencv_text.so.4.3.0 /usr/local/lib/libopencv_dnn.so.4.3.0 /usr/local/lib/libopencv_ml.so.4.3.0 /usr/local/lib/libopencv_phase_unwrapping.so.4.3.0 /usr/local/lib/libopencv_optflow.so.4.3.0 /usr/local/lib/libopencv_ximgproc.so.4.3.0 /usr/local/lib/libopencv_video.so.4.3.0 /usr/local/lib/libopencv_videoio.so.4.3.0 /usr/local/lib/libopencv_imgcodecs.so.4.3.0 /usr/local/lib/libopencv_objdetect.so.4.3.0 /usr/local/lib/libopencv_calib3d.so.4.3.0 /usr/local/lib/libopencv_features2d.so.4.3.0 /usr/local/lib/libopencv_flann.so.4.3.0 /usr/local/lib/libopencv_photo.so.4.3.0 /usr/local/lib/libopencv_imgproc.so.4.3.0 /usr/local/lib/libopencv_core.so.4.3.0 -Wl,--no-as-needed,/usr/local/libtorch/lib/libtorch_cpu.so -Wl,--as-needed /usr/local/libtorch/lib/libc10.so -lpthread -Wl,--no-as-needed,/usr/local/libtorch/lib/libtorch.so -Wl,--as-needed
I've tried a lot of different combination of commands, but I cannot figure our what's wrong.
When I echo the TORCH_LIBRARIES variable, it returns:
torch;torch_library;/usr/local/libtorch/lib/libc10.so
If I change the libaries, for example to torch_cpu, I'm able to link OpenCV libraries.
set(TORCH_LIBRARIES torch_cpu)
I have no idea why Torch libraries are causing link errors with OpenCV in the same project.
Any suggestions would be great.
Not sure if this fixes your problem, but I had also a few problems like yours. It is working for me with a cmake file including this:
cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
project(MyProject)
set(CMAKE_CXX_STANDARD 14)
list(APPEND CMAKE_PREFIX_PATH "folderToLibtorch/libtorch/share/cmake")
find_package(Torch REQUIRED)
find_package(OpenCV REQUIRED)
SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -lm -ldl")
add_executable(MyProject ...some project files...)
target_link_libraries(MyProject ${TORCH_LIBRARIES} ${OpenCV_LIBS})
set_property(TARGET MyProject PROPERTY CXX_STANDARD 14)
So make sure list(APPEND CMAKE_PREFIX_PATH "folderToLibtorch/libtorch/share/cmake") is included, this did the trick for me. Also take care to get the right libtorch version from pytorch maybe you should use the lower link and not the "pre-..." version.
Good Luck
The problem is in the version libtorch.
Please use libtorch-cxx11-abi-shared-with-deps not libtorch-shared-with-deps. It is library conflict between libtorch and opencv.
Solution here.
There is my version of CMakeList.txt with CUDA+LIBTORCH+OPENCV support:
cmake_minimum_required(VERSION 3.8 FATAL_ERROR)
SET(CUDA_HOME /usr/local/cuda)
SET(CMAKE_CUDA_COMPILER /usr/local/cuda/bin/nvcc)
SET(CUDA_TOOLKIT_ROOT_DIR /usr/local/cuda)
# SET(CUDA_CUBLAS_LIBRARIES /usr/local/cuda/lib64)
SET(CUDA_cublas_device_LIBRARY /usr/local/cuda/lib64)
# SET(CMAKE_CUDA_COMPILER_ENV_VAR /usr/local/cuda/bin/nvcc)
SET(CUDA_INCLUDE_DIRS /usr/local/cuda/include)
if(NOT DEFINED CMAKE_CUDA_ARCHITECTURES)
set(CMAKE_CUDA_ARCHITECTURES 50)
endif()
set(OpenCV_DIR /usr/local/lib/cmake/opencv4)
# set(OpenCV_DIR /usr/local/lib)
project(cmake_and_cuda LANGUAGES CXX CUDA)
include(CTest)
find_package(CUDA REQUIRED)
# libtorch with OpenCV support , with fixed BUG !
list(APPEND CMAKE_PREFIX_PATH ./libtorch)
find_package(Torch REQUIRED)
message(STATUS "TORCH_LIBRARIES = ${TORCH_LIBRARIES}")
find_package(OpenCV REQUIRED)
message(STATUS "OpenCV_LIBS = ${OpenCV_LIBS}")
# ADD OWN CUDA FILES FOR BUILD LIBRARY.
add_library(particles_new_lib STATIC
torch_module_plus_cuda.cu
torch_module_plus_cuda.h
)
target_compile_features(particles_new_lib PUBLIC cxx_std_14)
# We need to explicitly state that we need all CUDA files in the
# particles_new_lib library to be built with -dc as the member functions
# could be called by other libraries and executables
set_target_properties( particles_new_lib
PROPERTIES CUDA_SEPARABLE_COMPILATION ON)
add_executable(particle_cuda_test torch_and_cuda_call.cpp)
set_property(TARGET particle_cuda_test
PROPERTY CUDA_SEPARABLE_COMPILATION ON)
# LINK ALL LIBRARIES TO TARGET particle_cuda_test
target_link_libraries(particle_cuda_test PRIVATE ${TORCH_LIBRARIES} ${OpenCV_LIBS} particles_new_lib)
# LINK LIBRARIES
target_link_libraries(particle_cuda_test PRIVATE particles_new_lib)
set_property(TARGET particle_cuda_test PROPERTY CXX_STANDARD 14)
I am trying to integrate the new Opencv3.3rc tag to use OpenCV dnn module.
https://github.com/opencv/opencv/tree/3.3.0-rc
I can cross compile the OpenCV library but when I try to make the FindOpencv required I have this error:
Some (but not all) targets in this export set where already defined.
The unique target registered is cpufeatures as you can see:
Targets Defined: cpufeatures
Targets not yet defined:
libtiff;libjpeg;libwebp;libjasper;libpng;IlmImf;tegra_hal;libprotobuf;opencv_core;opencv_flann;opencv_imgproc;opencv_ml;opencv_objdetect;opencv_photo;opencv_video;opencv_dnn;opencv_imgcodecs;opencv_shape;opencv_videoio;opencv_highgui;opencv_superres;opencv_features2d;opencv_calib3d;opencv_java;opencv_stitching;opencv_videostab
As I can see in the OpenCVconfig.cmake configuration file, currently, there are two methods to find OpenCV:
this:
find_package(OpenCV REQUIRED)
or defining modules:
find_package(OpenCV REQUIRED core videoio)
But none of them works.
The error comes from this snippet OpenCVModules.cmake
# Commands may need to know the format version.
set(CMAKE_IMPORT_FILE_VERSION 1)
# Protect against multiple inclusion, which would fail when already imported targets are added once more.
set(_targetsDefined)
set(_targetsNotDefined)
set(_expectedTargets)
foreach(_expectedTarget cpufeatures libtiff libjpeg libwebp libjasper libpng IlmImf tegra_hal libprotobuf opencv_core opencv_flann opencv_imgproc opencv_ml opencv_objdetect opencv_photo opencv_video opencv_dnn opencv_imgcodecs opencv_shape opencv_videoio opencv_highgui opencv_superres opencv_features2d opencv_calib3d opencv_java opencv_stitching opencv_videostab)
list(APPEND _expectedTargets ${_expectedTarget})
if(NOT TARGET ${_expectedTarget})
list(APPEND _targetsNotDefined ${_expectedTarget})
endif()
if(TARGET ${_expectedTarget})
list(APPEND _targetsDefined ${_expectedTarget})
endif()
endforeach()
if("${_targetsDefined}" STREQUAL "${_expectedTargets}")
unset(_targetsDefined)
unset(_targetsNotDefined)
unset(_expectedTargets)
set(CMAKE_IMPORT_FILE_VERSION)
cmake_policy(POP)
return()
endif()
if(NOT "${_targetsDefined}" STREQUAL "")
message(FATAL_ERROR "Some (but not all) targets in this export set were already defined.\nTargets Defined: ${_targetsDefined}\nTargets not yet defined: ${_targetsNotDefined}\n")
endif()
Anybody knows how this could happen?
I found the answer:
I was defining the cpu-features library before, so this code was the conflicting part in the CMakelists.txt.
add_library(cpufeatures STATIC
${ANDROID_NDK}/sources/android/cpufeatures/cpu-features.c)
Removing this part, the problem was solved.
My problem is similar with this: http://www.eclipse.org/forums/index.php/m/649323/
I created a cmake project, and used
cmake .. -G "Eclipse CDT4 - Unix Makefiles"
to create a Eclipse CDT4 project.
But in the CDT IDE, the standard include paths are not listed, and all STL or system build-in header files include directives are marked as "cannot be resolved", so the "Open Declaration" or other a lot of operation cannot be done.
However, I could compile it without any problems.
My co-worker also has a cmake project, but it's very complicated. The CDT project generated from his cmake project DOES have the system includes. But his cmake is way too complicated, and he told me that he didn't do anything special to include the system paths.
Can anyone help me out? Thanks.
My Main CMakeLists.txt:
CMake_Minimum_Required(VERSION 2.8)
# Some settings
Set(CMAKE_ALLOW_LOOSE_LOOP_CONSTRUCTS ON)
CMake_Policy(SET CMP0015 NEW)
#Include(CMakeProcedures.cmake)
#CheckEnvironment()
# Set the compiler and its version if needed
# Create the project
Project(MyProjectName CXX)
# Set the compiler
Set(CMAKE_CXX_COMPILER /usr/bin/g++)
# Detect whether we are in-source
If (CMAKE_SOURCE_DIR STREQUAL CMAKE_BINARY_DIR)
Message(FATAL_ERROR "In-source building is not allowed! Please create a 'build' folder and then do 'cd build; cmake ..'")
EndIf()
# Set the output dirs
Set(EXECUTABLE_OUTPUT_PATH ${PROJECT_BINARY_DIR}/bin)
Set(LIBRARY_OUTPUT_PATH ${PROJECT_BINARY_DIR}/lib)
# Add source subdirs to the build
Add_Subdirectory(src)
# Add_Subdirectory(test EXCLUDE_FROM_ALL)
Peter
One workaround is to manually add these to the CDT IDE:
/usr/include/c++/4.5
/usr/include/c++/4.5/backward
/usr/include/c++/4.5/i686-linux-gnu
/usr/include/i386-linux-gnu
/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5.2/include
/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5.2/include-fixed
/usr/local/include
But it's not the solution.
I finally figured out that this line is causing the problem:
Project(MyProjectName CXX)
If we remove the optional paramter CXX, life is good.
Can anyone tell me why?
Peter
I hope you can help me.
I have a simple CMakeLists.txt in order to build my project on Leopard 10.5.8.
I'm using CMake 2.8.1 and at the moment this is the code:
cmake_minimum_required(VERSION 2.8)
MESSAGE(STATUS "./src: Going into utils folder")
ADD_SUBDIRECTORY(utils)
MESSAGE(STATUS "./src: utils folder processed")
include_directories(${DIR}/headers)
link_directories (${DIR}/src/utils)
ADD_EXECUTABLE(sample sample.cpp)
TARGET_LINK_LIBRARIES(sample libSample ${EXTERNAL_LIBS})
INSTALL(TARGETS sample DESTINATION "./src")
MESSAGE(STATUS "./src: exiting src folder")
I need to add OpenCV libraries on my project.
When I use Eclipse I set the include path to /opt/local/include
and the libraries path to: /opt/local/lib and then I specify the libraries name such as_ opencv_core, opencv_imgproc, opencv_video.
Can you tell me how to add these information in the CMakeLists.txt file, please?
I've read some information in the official cmake FAQ but i wasn't able to solve my problem.
Please, help me.
Thanks a lot.
You need to add the library names in the TARGET_LINK_LIBRARIES command, but you need to add them without the lib prefix. For example:
include_directories(${DIR}/headers /opt/local/include)
link_directories (${DIR}/src/utils /opt/local/lib)
ADD_EXECUTABLE(sample sample.cpp)
TARGET_LINK_LIBRARIES(sample opencv_core opencv_imgproc opencv_video ${EXTERNAL_LIBS})