Static linking DCMTK library - c++

I use DCMTK in my application and for compilation use cmake file. cmake finds all libraries (at least headers, because in compiles source files to .o files) the only problem is that during linking it tries to find dynamic libraries for DCMTK. I compiled one as static, so I do not have .so files. As a result it gives me error :No rule to make target /usr/lib/libdcmdata.so, needed by dcm_seg. Stop.
I use Ubuntu 14.04 x64.
It confuses me pretty much. So, what's the problems?
cmake file:
cmake_minimum_required(VERSION 2.6)
project(dcm_segm)
set(CMAKE_CXX_FLAGS "-std=c++0x ${CMAKE_CXX_FLAGS} -g -ftest-coverage -fprofile-arcs")
set(Boost_USE_STATIC_LIBS ON)
set(OpenCV_USE_STATIC_LIBS ON)
set(DCMTK_USE_STATIC_LIBS ON)
set(OpenCV_STATIC ON)
find_package( VTK REQUIRED )
find_package( OpenCV REQUIRED )
find_package( Boost COMPONENTS system filesystem REQUIRED )
find_package( DCMTK REQUIRED )
include(${VTK_USE_FILE} )
link_directories(${OpenCV_LIB_DIR})
add_executable(dcm_seg main.cpp DICOMin.cpp Ensemble.cpp Ensemble3dExtension.cpp point_3d.cpp RegionGrow.cpp)
target_link_libraries(dcm_seg ${VTK_LIBRARIES} ${OpenCV_LIBS} ${DCMTK_LIBRARIES} ${Boost_LIBRARIES})

Can you check the content of ${DCMTK_LIBRARIES} (it should be a list of paths to DCMTK static libraries) ?
you can also check the following CMake entries during the CMake configuration:
DCMTK_DIR /path/to/DCMTK/install
DCMTK_config_INCLUDE_DIR /path/to/DCMTK/install/include/dcmtk/config
DCMTK_dcmdata_INCLUDE_DIR /path/to/DCMTK/install/dcmdata/include/dcmtk/dcmdata
DCMTK_dcmdata_LIBRARY_DEBUG /path/to/DCMTK/install/dcmdata/libsrc/libdcmdata.a
DCMTK_dcmdata_LIBRARY_RELEASE /path/to/DCMTK/install/dcmdata/libsrc/libdcmdata.a
[...]
Another hint: I noted in the past that find DCMTK from a build instead of an install not always works properly.
If you have trouble finding DCMTK with the script provided with CMake
(${DCMTK_LIBRARIES} doesn not content the path to you static DCMTK libs for example) you can try to use this alternative script

Related

How to properly link OpenCV in a C++ cross-platform library for Android and iOS?

I am developing a C++ library, including OpenCV, which will be used in a cross-platform Xamarin solution through a wrapper and the NuGet packaging system (see this guide). I configured a CMakeLists.txt file but I simply cannot get OpenCV to be correctly linked for both static (iOS) and dynamic (Android) libraries.
I tried to change the OpenCV_DIR variable, install and build OpenCV from sources and manually include the content of the OpenCV_INCLUDE_DIRS variable but nothing worked. I also noticed that the linking works when only using cv::Point. But the linking does not work when using cv::Mat, which I do not understand the reason.
The following is the CMakeLists.txt that I am using :
cmake_minimum_required (VERSION 3.2)
project (MyLib C CXX)
enable_testing()
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
MESSAGE(STATUS "CMAKE_CXX_FLAGS: " ${CMAKE_CXX_FLAGS})
# Source and headers files
set(SOURCES File1.cpp File2.cpp)
set(HEADERS File1.h File2.h)
# Library
if(BUILD_SHARED_LIBS)
add_library (MyLib SHARED ${SOURCES} ${HEADERS})
target_compile_definitions(MyLib PUBLIC IS_BUILDING_SHARED)
else()
add_library (MyLib STATIC ${SOURCES} ${HEADERS})
endif()
# Dependencies
set(OpenCV_DIR /usr/local/Cellar/opencv/4.5.0_1/lib/cmake/opencv4)
find_package(OpenCV REQUIRED)
message(STATUS "OpenCV_INCLUDE_DIRS = ${OpenCV_INCLUDE_DIRS}")
message(STATUS "OpenCV_LIBS = ${OpenCV_LIBS}")
message(STATUS "OpenCV_DIR = ${OpenCV_DIR}")
include_directories(${OpenCV_INCLUDE_DIRS})
target_link_libraries(MyLib ${OpenCV_LIBS})
The following shows the location of OpenCV's files that are used during the build process. Everything seems alright.
-- OpenCV_INCLUDE_DIRS = /usr/local/Cellar/opencv/4.5.0_1/include/opencv4
-- OpenCV_LIBS = opencv_calib3d;opencv_core;opencv_dnn;opencv_features2d;opencv_flann;opencv_gapi;opencv_highgui;opencv_imgcodecs;opencv_imgproc;opencv_ml;opencv_objdetect;opencv_photo;opencv_stitching;opencv_video;opencv_videoio;opencv_alphamat;opencv_aruco;opencv_bgsegm;opencv_bioinspired;opencv_ccalib;opencv_datasets;opencv_dnn_objdetect;opencv_dnn_superres;opencv_dpm;opencv_face;opencv_freetype;opencv_fuzzy;opencv_hfs;opencv_img_hash;opencv_intensity_transform;opencv_line_descriptor;opencv_mcc;opencv_optflow;opencv_phase_unwrapping;opencv_plot;opencv_quality;opencv_rapid;opencv_reg;opencv_rgbd;opencv_saliency;opencv_sfm;opencv_shape;opencv_stereo;opencv_structured_light;opencv_superres;opencv_surface_matching;opencv_text;opencv_tracking;opencv_videostab;opencv_viz;opencv_xfeatures2d;opencv_ximgproc;opencv_xobjdetect;opencv_xphoto
-- OpenCV_DIR = /usr/local/Cellar/opencv/4.5.0_1/lib/cmake/opencv4
Android
The following is the commands that I am using to build the Android dynamic library (.so). I have installed the NDK and am building for each ABI (x86, x86_64, armeabi-v7a, arm64-v8a).
cmake ../.. -DCMAKE_TOOLCHAIN_FILE=/Users/$USER/Library/Android/sdk/ndk-bundle/build/cmake/android.toolchain.cmake -DANDROID_NATIVE_API_LEVEL=21 -DANDROID_ABI=$abi_name -DBUILD_SHARED_LIBS=ON
cmake --build . --config Release
I directly get an error when building the library which is the following.
ld: error: /usr/local/Cellar/opencv/4.5.0_1/lib/libopencv_gapi.4.5.0.dylib: unknown file type
ld: error: /usr/local/Cellar/opencv/4.5.0_1/lib/libopencv_stitching.4.5.0.dylib: unknown file type
[...]
ld: error: /usr/local/Cellar/opencv/4.5.0_1/lib/libopencv_rapid.4.5.0.dylib: unknown file type
ld: error: too many errors emitted, stopping now (use -error-limit=0 to see all errors)
clang++: error: linker command failed with exit code 1 (use -v to see invocation)
iOS
The following is the commands that I am using to build the iOS static library (.a). I am using leetal's ​cmake toolchain file from this repository.
cmake ../.. -G Xcode -DCMAKE_TOOLCHAIN_FILE=../../ios.toolchain.cmake -DPLATFORM=OS64COMBINED -DBUILD_SHARED_LIBS=OFF
cmake --build . --config Release
The compilation of the static library seems to work because no error message is printed. However, when the library is used in the final Xamarin solution, the linked library cannot be found and the following error is shown.
Native linking failed, undefined symbol: cv::Mat::deallocate(). Please verify that all the necessary frameworks have been referenced and native libraries are properly linked in. (MT5210)
Question
What am I missing in order to properly compile and link OpenCV into my C++ library ?
I am working on macOS Big Sur and uses the following tools versions:
cmake : 3.20.0-rc5
ndk : 23.0.7196353
apple clang : 12.0.0
I hope that the description of my problem is clear enough and I thank you in advance for any help.
We had same problems, including Xamarin's DllNotFoundException with message from last comment, which led me to this topic. What fixed the exception for us in the end was linking statically to OpenCV *.a libs instead of linking to the shared libopencv_java4.so file. So we now have a huge 30MB nativelib.so file for each android ABI in build output, instead of a pair of small nativelib.so and libopencv_java4.so per ABI. CMakeLists looks like this:
set( OpenCV_DIR "~/opencv/build/OpenCV-android-sdk/sdk/native/jni" )
find_package( OpenCV REQUIRED )
target_link_libraries( # Specifies the target library.
nativelib
${OpenCV_LIBS})
Another thing in our project is we use OpenCV optional modules and had to create a custom OpenCV build, which I guess ensures our native library and OpenCV are compiled against same NDK version. I suppose using the prebuilt OpenCV distribution and compiling against a different NDK version could lead to problems too otherwise.

How to build static library with bundled dependencies - CMake

I am currently using CMake to create a static library which utilizes a few of the static libraries from OpenCV 4 ( core imgcodecs video highgui imgproc ). My intention is to be able to bundle all of the required OpenCV static libraries into my own library so that I can distribute it as one library. Additionally, I want for the user of my library to not have to install OpenCV 4 on their system (but do not mind if the user has to do simple installs using apt-get install). I know there are tools for bundling static libraries (such as using ar for linux).
However, where I really am having the issue is with all the dependencies of OpenCV (such as libjpeg, libpng, etc). I don't necessarily mind if these libraries are bundled with mine or linked dynamically as they are relatively easy to install (can be installed with sudo apt-get install, whereas opencv4 needs to be built from source).
What is the best way to go about doing this?
This is my current CMakeLists.txt
It is currently working, but that is because I am using find_package(OpenCV REQUIRED) (which defeats the purpose of what I am trying to do). When I remove that line, the linker complains about not being able to find the OpenCV dependencies.
cmake_minimum_required(VERSION 2.8)
project(myproject)
set(CMAKE_CXX_STANDARD 14)
include_directories(${CMAKE_CURRENT_LIST_DIR}/include)
link_directories(${CMAKE_CURRENT_LIST_DIR}/lib)
find_package(OpenMP REQUIRED)
find_package(OpenCV REQUIRED)
set(JSON_BuildTests OFF CACHE INTERNAL "")
add_subdirectory(nlohmann_json)
list(APPEND LINKER_LIBS opencv_core opencv_highgui opencv_video opencv_imgcodecs libmxnet.so libncnn.a nlohmann_json::nlohmann_json)
file(GLOB SRC${CMAKE_CURRENT_LIST_DIR}/src/*.cpp${CMAKE_CURRENT_LIST_DIR}/main.cpp)
add_library(myproject ${SRC})
target_link_libraries(myproject ${LINKER_LIBS} ${OpenMP_CXX_FLAGS})
To elaborate on my question. I build my project which generates libmyproject.a. I then take this library and will eventually extract the symbols from the OpenCV libs (libopencv_core.a libopencv_highgui.a libopencv_imgcodecs.a libopencv_video.a) and add them to my lib (for the time being, I have not yet done this step, which is why in the below example I am linking libopencv_*). I then use my library in a new project, for which the CMakeLists.txt is shown below:
cmake_minimum_required(VERSION 2.8)
project(myproject-driver)
set(CMAKE_CXX_STANDARD 14)
include_directories(${CMAKE_CURRENT_LIST_DIR}/include)
link_directories(${CMAKE_CURRENT_LIST_DIR}/lib)
find_package(OpenMP REQUIRED)
add_executable(myproject-driver main.cpp)
target_link_libraries(myproject-driver myproject libncnn.a ${OpenMP_CXX_FLAGS} libmxnet.so libopencv_core.a libopencv_highgui.a libopencv_imgcodecs.a libopencv_video.a)
Building this generates the following errors:
Linking CXX executable myproject-driver
/usr/bin/ld: /home/nchafni/Cyrus/myproject/lib/libopencv_imgcodecs.a(grfmt_jpeg.cpp.o): undefined reference to symbol 'jpeg_default_qtables##LIBJPEG_8.0'
//usr/lib/x86_64-linux-gnu/libjpeg.so.8: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
How can I fix this. Is there some CMake command which will link all these dependencies for me? Do I need to manually track down each dependency of those libopencv_* libs and link those manually? Once again, this is assuming that the person using libmyproject.a can't use find_package(OpenCV REQUIRED) as it won't be defined as they have not installed OpenCV on their machine.
First of all, don't use the super old and outdated version 2.8 of CMake. CMake 3.x is so much more powerful and pretty straightforward to use.
Some tips for modern CMake.
Don't use file(GLOB), see here why that is.
Don't use directory wide instructions, rather use target instructions, e.g. target_include_directories vs. include_directories.
Don't use string variables like ${<PACKAGE_NAME>_LIBRARIES}, rather use targets, e.g. <Package_NAME>::lib
When using targets instead of string variables, all the properties (including LINK_INTERFACE) of that target will be populated to the library/executable when calling target_link_libraries, so no more include_directories,link_directories, etc.
myproject
cmake_minimum_required(VERSION 3.14)
project(myproject)
set(CMAKE_CXX_STANDARD 14)
find_package(OpenMP REQUIRED)
find_package(OpenCV REQUIRED)
set(JSON_BuildTests OFF CACHE INTERNAL "")
add_subdirectory(nlohmann_json)
set(SOURCES ...) # list all the source files here
add_library(myproject ${SOURCES})
target_include_directories(myproject PUBLIC # give it a scope
${CMAKE_CURRENT_LIST_DIR}/include
)
target_link_libraries(myproject PUBLIC # give it a scope
opencv_core # using the target, you will get all LINK_LIBRARIES
opencv_highgui
opencv_video
opencv_imgcodecs
libmxnet.so # where is this coming from?
libncnn.a # where is this coming from?
nlohmann_json::nlohmann_json
OpenMP::OpenMP_CXX ## linking against a target, CXX_FLAGS will be populated automatically
)
myprojec-driver
cmake_minimum_required(VERSION 3.14)
project(myproject-driver)
set(CMAKE_CXX_STANDARD 14)
add_executable(myproject-driver main.cpp)
target_link_libraries(myproject-driver PUBLIC # give it a scope
myproject # gets all dependencies through the LINK_INTERFACE
)

proper way to write a CMakeLists referencing HDF5 in Windows

I've already downloaded an built HDF5 under Windows using CMake, I also generated an installer to install it under Program Files.
Below the CMakeLists.txt I wrote to be able to use HDF5 in a program I already wrote under Linux :
cmake_minimum_required(VERSION 2.8)
project(Hdf5DataFeed)
add_definitions(-DWINDOWS)
find_package(HDF5)
FIND_LIBRARY(HDF5_HL_LIBRARY hdf5_hl)
FIND_LIBRARY(ZLIB zlib)
find_library(ZMQ_LIB zmq)
find_package(VTK REQUIRED)
include(${VTK_USE_FILE})
include_directories(${ZMQ_LIB_INCLUDE})
aux_source_directory(. SRC_LIST)
add_executable(${PROJECT_NAME} ${SRC_LIST})
target_link_libraries(${PROJECT_NAME} ${ZLIB} "C:/Program Files/HDF_Group/HDF5/1.10.1/lib/libszip.lib" ${VTK_LIBRARIES} ${ZMQ_LIB} ${HDF5_LIBRARIES} ${HDF5_HL_LIBRARY} Qt5::Core Qt5::Gui Qt5::Widgets)
target_include_directories(${PROJECT_NAME} PRIVATE ${HDF5_INCLUDE_DIRS})
As you can see above, to link HDF5 under Visual Studio, I needed Zlib, Szip (that I had to enter an absolute path to it, I don't like that), HDF5 library and the HDF5 High Level (Lite) library.
These libraries are located under C:\Program Files\HDF_Group\HDF5\1.10.1\lib :
libhdf5.lib <============
libhdf5.settings
libhdf5_cpp.lib
libhdf5_hl.lib <=====
libhdf5_hl_cpp.lib
libhdf5_tools.lib
libszip.lib <=== ????
libzlib.lib <====
I use CMake-Gui to inform CMake of the libraries path (except for Szip, I don't know why CMake doesn't know about it, and why I don't have the possibility to just feed CMake the library directory instead of indicating the path of few of them).
I want to use CMake-GUI to inform CMake of Szip library path, but this last doesn't create an entry of it, I only have these entries related to HDF5 :
I'm having troubles with HDF5 also under Ubuntu (see this question : hdf5.h no such file or directory under Ubuntu and CMake).
For now, it's only under CentOS 7 that I didn't encounter any issues with HDF5.
If someone can give me/us a final solution that works both on Windows and Ubuntu that would be great !
Does this solution work for you?
cmake_minimum_required(VERSION 2.8)
project(Hdf5DataFeed)
# necessary?
add_definitions(-DWINDOWS)
find_package(HDF5 REQUIRED COMPONENTS C CXX HL)
find_package(ZLIB REQUIRED)
find_package(VTK REQUIRED)
include(${VTK_USE_FILE})
find_library(ZMQ_LIB zmq)
include_directories(${ZMQ_LIB_INCLUDE} ${HDF5_INCLUDE_DIR}
${ZLIB_INCLUDE_DIRS})
aux_source_directory(. SRC_LIST)
add_executable(${PROJECT_NAME} ${SRC_LIST})
target_link_libraries(${PROJECT_NAME} ${HDF5_LIBRARIES}
${HDF5_HL_LIBRARIES} ${ZLIB_LIBRARIES} ${VTK_LIBRARIES}
Qt5::Core Qt5::Gui Qt5::Widgets ${ZMQ_LIB})
Recommendation 1: Surely, there is a way to find Qt5 via find_package, i.e.,
find_package(Qt5 COMPONENTS Core Widgets REQUIRED)
and then add the correct variables to include_directories and target_link_libraries. Not sure whether such a possibility exists for the zmq library, though.
Recommendation 2: I think the call the aux_source_directory should be avoided in most cases. Create an explicit list of your source files instead.
For libszip, adding a find_library is better than putting an absolute link to it. For ZLib, it is preferable to use find_library as find_package will require you to feed CMake with an include directory which is not required for HDF5. Finally, it is preferable to use find_package for ZMQ, otherwise, we need to add manually the entry "ZMQ_LIB_INCLUDE".

CMake linking Boost: cannot find -lboost_program_options

I want to use Boosts support for command line flags in C++ on Linux. I use CMake to build the application, but I get a error "cannot find -lboost_program_options". The library boost_program_options was build independently using bjam, and the libraries are in the stage/lib subdirectory of the boost directory.
What does work: A solution is to add the stage/lib library using link_directories, but the CMake manual states:
Note that this command is rarely necessary. Library locations returned by find_package() and find_library() are absolute paths.
So that should not be nescessary.
What I want to have working:
Using find_package should be enough, but that doesn't work, here's the CMakeLists:
cmake_minimum_required(VERSION 3.6)
project(inp_manipulation)
set(CMAKE_CXX_STANDARD 11)
include_directories(includes lib/boost_1_62_0 lib/)
SET(CMAKE_INCLUDE_PATH ${CMAKE_INCLUDE_PATH} "lib/boost_1_62_0")
SET(CMAKE_LIBRARY_PATH ${CMAKE_LIBRARY_PATH} "lib/boost_1_62_0/stage/lib")
find_package(Boost 1.62.0)
include_directories(${Boost_INCLUDE_DIR})
file(GLOB SOURCES *.cpp)
set(MAIN_FILE main.cpp)
set(SOURCE_FILES ${SOURCES})
add_executable(inp_manipulation ${MAIN_FILE} ${SOURCE_FILES} )
target_link_libraries(inp_manipulation -static-libgcc -static-libstdc++ boost_program_options)
Question
Where is the mistake in the CMakeLists?
Thanks in advance!
First, you must tell cmake that you require the specific component library from boost:
find_package(Boost 1.62.0 COMPONENTS program_options)
Second, always use the output variables from BoostFind.cmake
target_link_libraries(inp_manipulation -static-libgcc -static-libstdc++ ${Boost_LIBRARIES})
Documentation here: https://cmake.org/cmake/help/v3.0/module/FindBoost.html
Output variables are:
Boost_FOUND - True if headers and requested libraries were found
Boost_INCLUDE_DIRS - Boost include directories
Boost_LIBRARY_DIRS - Link directories for Boost libraries
Boost_LIBRARIES - Boost component libraries to be linked
etc

CMake third party library undefined reference

I already read and searched a lot (e.g. 1 2 3, several docs for CMake, similar projects, etc. to find a solution but I have not been able to solve my problem. I am relatively new to Cmake and Linux (Ubuntu 14.04).
I want to use libsbp (https://github.com/swift-nav/libsbp) to write a program in C++ to communicate with a GPS module. I cloned the repository and installed the C-Library. So now in /usr/local/lib there are two files: libsbp.so and libsbp-static.a and the headers are in /usr/local/include/libsbp
In my own project I include the headers with #include "libsbp/sbp.h" which also works.
Now the Problem: if I want to use a method from libsbp e.g. sbp_state_init(&s); I get undefined reference to "sbp_state_init(sbp_state_t*)"
The relevant part of my Cmake for my own project:
link_directories(/usr/local/lib)
add_executable(main ${QT_SOURCES} ${QT_HEADER_HPP})
target_link_libraries(main ${QT_LIBRARIES} ${catkin_LIBRARIES} sbp)
As I said before, I tried some things:
find_library(SBP_LIB sbp /usr/local/lib) -> same error
same goes for using libsbp in target_link_libraries or searching for it
link_directory(/usr/local/lib)
trying different paths, even moveing libsbp.so into the project directory and "finding" it with ${CMAKE_CURRENT_SOURCE_DIR}
Maybe you can help me!
edit:
this is the CMakeList.txt from the libsbp/c/src directory
if (NOT DEFINED BUILD_SHARED_LIBS)
set(BUILD_SHARED_LIBS ON)
endif (NOT DEFINED BUILD_SHARED_LIBS)
file(GLOB libsbp_HEADERS "${PROJECT_SOURCE_DIR}/include/libsbp/*.h")
include_directories("${PROJECT_SOURCE_DIR}/CBLAS/include")
include_directories("${PROJECT_SOURCE_DIR}/clapack-3.2.1-CMAKE/INCLUDE")
include_directories("${PROJECT_SOURCE_DIR}/lapacke/include")
include_directories("${PROJECT_SOURCE_DIR}/include/libsbp")
set(libsbp_SRCS
edc.c
sbp.c
)
add_library(sbp-static STATIC ${libsbp_SRCS})
install(TARGETS sbp-static DESTINATION lib${LIB_SUFFIX})
if(BUILD_SHARED_LIBS)
add_library(sbp SHARED ${libsbp_SRCS})
install(TARGETS sbp DESTINATION lib${LIB_SUFFIX})
else(BUILD_SHARED_LIBS)
message(STATUS "Not building shared libraries")
endif(BUILD_SHARED_LIBS)
install(FILES ${libsbp_HEADERS} DESTINATION include/libsbp)
this is the CMakeList.txt from /libsbp/c/
cmake_minimum_required(VERSION 2.8.9)
project(libsbp)
# Setup flags for Code Coverage build mode
set(CMAKE_CXX_FLAGS_COVERAGE "${CMAKE_CXX_FLAGS_DEBUG} --coverage" CACHE STRING
"Flags used by the C++ compiler for building with code coverage."
FORCE )
set(CMAKE_C_FLAGS_COVERAGE "${CMAKE_C_FLAGS_DEBUG} --coverage" CACHE STRING
"Flags used by the C compiler for building with code coverage."
FORCE )
SET(CMAKE_EXE_LINKER_FLAGS_COVERAGE
"${CMAKE_EXE_LINKER_FLAGS_DEBUG} --coverage" CACHE STRING
"Flags used for linking binaries with code coverage."
FORCE )
set(CMAKE_SHARED_LINKER_FLAGS_COVERAGE
"${CMAKE_SHARED_LINKER_FLAGS_DEBUG} --coverage" CACHE STRING
"Flags used by the shared libraries linker during builds with code coverage."
FORCE )
mark_as_advanced(
CMAKE_CXX_FLAGS_COVERAGE
CMAKE_C_FLAGS_COVERAGE
CMAKE_EXE_LINKER_FLAGS_COVERAGE
CMAKE_SHARED_LINKER_FLAGS_COVERAGE )
# Update the documentation string of CMAKE_BUILD_TYPE for GUIs
set(CMAKE_BUILD_TYPE "${CMAKE_BUILD_TYPE}" CACHE STRING
"Choose the type of build, options are: None Debug Release RelWithDebInfo MinSizeRel Coverage."
FORCE )
# Set project version using Git tag and hash.
execute_process(
COMMAND git describe --dirty --tags --always
WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
RESULT_VARIABLE GIT_VERSION_FOUND
ERROR_QUIET
OUTPUT_VARIABLE GIT_VERSION
OUTPUT_STRIP_TRAILING_WHITESPACE
)
if (GIT_VERSION_FOUND)
set(VERSION "unknown")
else (GIT_VERSION_FOUND)
set(VERSION ${GIT_VERSION})
endif (GIT_VERSION_FOUND)
# Set project version explicitly for release tarballs.
#set(VERSION foo)
message(STATUS "libsbp version: ${VERSION}")
cmake_minimum_required(VERSION 2.8)
set(CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}/cmake")
# Some compiler options used globally
set(CMAKE_C_FLAGS "-Wall -Wextra -Wno-strict-prototypes -Wno-unknown-warning-option -Werror -std=gnu99 ${CMAKE_C_FLAGS}")
add_subdirectory(src)
add_subdirectory(docs)
add_subdirectory(test)
It seems that your program uses C++ and the library is written in C.
Symbols in C and C++ are encoded differently (mangled). When including C headers from C++ you need to tell the compiler. This can be done by declaring the symbols extern "C".
extern "C" {
#include <libsbp/sbp.h>
}
Some libraries already include this in their headers, but not sbp.
You have (at least) two possibilities:
Installing the library (this is what you did)
Integrating the library in your CMake project
When installing the library, the target_link_libraries command needs to be modified slightly:
find_library(SBP_LIB sbp /usr/local/lib)
target_link_libraries(main ${QT_LIBRARIES} ${catkin_LIBRARIES} ${SBP_LIB})
When you integrate the library in your CMake project, you can directly use the following command without using find_library. This works, because the library is known to CMake since it is built within the current project.
target_link_libraries(main ${QT_LIBRARIES} ${catkin_LIBRARIES} sbp)