It is my first time using stack overflow so I am a bit new with this. I've been working on a personal robotics project and I have downloaded a GitHub directory. I've already compiled it, tested it (it works) and I've generated the library.a file (because I'm working with Ubuntu 16.04 and ROS Kinetic). What I do not know is what I have to add to my CMakeLists.txt file in order to load the communication functions on a ROS node cpp file.
My actual description for compilation on the CMakeLists.txt file is the following one:
...
add_executable(test_node src/test_node.cpp)
add_dependencies(test_node ${catkin_EXPORTED_TARGETS})
target_link_libraries(test_node ${catkin_LIBRARIES})
...
I know that I have to add the library on the target_link_libraries if the library was an *.sofile, but it isn't. What should I add to my CMakeLists.txt file in order to load my library functions into my ROS node?
Your answer is based in a property on function add_library()
See this example block:
add_library(library_name STATIC IMPORTED)
set_target_properties(library_name PROPERTIES IMPORTED_LOCATION path/to/your/lib.a)
With this you can proceed to add this library with:
target_link_libraries(your_target library_name)
But don't forget to add this static library include files to your target.
The problem is solved with the following code:
...
find_package(Threads)
add_library(github_library STATIC IMPORTED GLOBAL)
set_target_properties(my_library PROPERTIES IMPORTED_LOCATION
my_library_directory/my_library.a)
...
target_link_libraries(my_cpp_ros_node ${catkin_LIBRARIES} my_library ${CMAKE_THREAD_LIBS_INIT})
...
Related
I am trying to use this ZED Open Capture library for using the ZED Mini camera for my project on RaspberryPi. I succesfully installed the library and the shared object file is at /usr/local/lib/libzed_open_capture.so and the include headers are at the location /usr/local/include/zed-open-capture/.
To include this library I am adding the following lines to my CMakeLists.txt
find_library(ZED_LIB zed_open_capture)
include_directories("/usr/local/include/zed-open-capture/")
add_executable(zed_pub src/zed_pub.cpp)
target_link_libraries(zed_pub ${ZED_LIB})
Now when I use this code , it shows this error "‘sl_oc::video’ has not been declared"
#include "videocapture.hpp" //Library Header File
sl_oc::video::VideoCapture cap;
cap.initializeVideo();
const sl_oc::video::Frame frame = cap.getLastFrame();
Can someone please explain me how a Shared Object Library file along with header files should be used in CMake? The library has already been installed using CMake build and sudo make install on my Linux system.
The github repo of the library is at https://github.com/stereolabs/zed-open-capture
Also I cannot find Find_PKG_name.cmake so I cannot use find_package() option.
videocapture.hpp wraps the definitions you need inside #ifdef VIDEO_MOD_AVAILABLE. It seems likely that this is not defined. The root CMakeLists.txt in the ZED package defaults BUILD_VIDEO to ON, so this was likely all defined for the package build. But as others have pointed out, the package does not persist this information anywhere in the installation. The "right" way for the package to do it would be EITHER to configure/modify the include files at install time to account for the build configuration, probably by generating a "config.hpp" file with the appropriate definitions. OR to include a zed-config.cmake file in the installation, with all the necessary imports and definitions.
Your short-circuit solution should be fine. Just add target_compile_definitions(zed_pub PUBLIC VIDEO_MOD_AVAILABLE). If you want to do it more cleanly for the future, create an IMPORTED target for zed_lib, and set both the include_directories and compile_definitions on that target, so that all users of the library get this defined automatically.
According to the ZED Open Capture's CMakeLists.txt:
...
# Install rules
set_target_properties(${PROJECT_NAME} PROPERTIES
PUBLIC_HEADER "${HDR_FULL}"
)
install(TARGETS ${PROJECT_NAME}
LIBRARY DESTINATION ${CMAKE_INSTALL_PREFIX}/lib
PUBLIC_HEADER DESTINATION ${CMAKE_INSTALL_PREFIX}/include/zed-open-capture)
ref: https://github.com/stereolabs/zed-open-capture/blob/dfa0aee51ccd2297782230a05ca59e697df496b2/CMakeLists.txt#L142-L148
ZED Open Capture seems to not provide any "CMake config" file...
So you must create your own FindZED.cmake module and/or improve the CMakeLists.txt of this project...
I have a project A that depends on spdlog. Here is the structure:
|--- dir A
...|---src
......|---CMakeLists.txt
...|---include
...|---CMakeLists.txt
|---external/3rd_party/spdlog
I am trying to access spdlog in project A by adding a subdirectory. Here is how my A/CMakeLists.txt looks like:
cmake_minimum_required(VERSION 3.9.3 FATAL_ERROR)
project(GLOBAL CXX)
add_subdirectory(../external/3rd_party/spdlog ${CMAKE_BINARY_DIR}/spdlog EXCLUDE_FROM_ALL)
add_subdirectory(src)
Here is how my A/src/CMakeLists.txt looks like:
cmake_minimum_required(VERSION 3.9.3 FATAL_ERROR)
project(Alib CXX)
if(NOT TARGET spdlog)
# Stand-alone build
find_package(spdlog_header_only REQUIRED)
endif()
add_librray(A A.cpp)
target_link_libraries(A PUBLIC spdlog_header_only)
install(TARGETS A
EXPORT ATargets
LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
)
install(EXPORT ATargets
NAMESPACE A::
FILE ATargets.cmake
DESTINATION ${INSTALL_CONFIGDIR})
install(FILES AConfig.cmake DESTINATION ${INSTALL_CONFIGDIR})
When I try to build this, I get the following error:
CMake Error: install(EXPORT "ATargets" ...) includes target "A" which requires target "spdlog_header_only" that is not in the export set.
Please can you suggest me how to fix it?
For some reason I need to maintain the same directory structure I have shown above.
Here is a related question but does not have an answer : here
Meaining of the error
Since you use PUBLIC keyword when link your library (A) with spdlog_header_only, CMake expects that this linking is also needed for users of your library. So, when you create config file for your library (with install(EXPORT)), CMake adds linking with spdlog_header_only target into the config file too. Like
# [ATargets.cmake]
target_link_libraries(A::A PUBLIC spdlog_header_only)
Linking with a target implies existence of this target, but you do not install spdlog_header_only target. Because of that, created config file for your library won't work. This is what CMake tells you in the error message.
Simple fix
The simplest fix would be using PRIVATE linking with spdlog_header_only target, so that linking won't be part of the config file. Beware, in that case a user of your (installed) library won't get access to the header files for spdlog.
(But a user could obtain these headers by other means.)
Hard fix
But if you want a user of your library to have access to spdlog headers (or, worse, the public headers of your library use #include for headers from spdlog), then you cannot drop PUBLIC linking. In that case you need to install spdlog_header_only target too. E.g. by enabling SPDLOG_INSTALL option
set(SPDLOG_INSTALL ON)
before
add_subdirectory(../external/3rd_party/spdlog ${CMAKE_BINARY_DIR}/spdlog EXCLUDE_FROM_ALL)
(Note, that aside from enabling SPDLOG_INSTALL option, several other adjustments needs to be done for make the config file for your library to work.)
I'm developing a c++ program on visual studio that will be deployed on linux, and it is debugged on linux through an ssh. Currently, this is the structure of my folder:
ANT
-xscommon
--xscommon_config.h
-xscontroller
-xstypes
ANT.cpp
ANT.h
CMakeLists.txt
CMakeSettings.json
hashes.h
quaternionic.h
stars.h
Currently, all the .h, .cpp, .o, .cpp.o, .a files that I think I have to link to are kept within the three xs------- directories. I am quite new to cmake, and this linking to these libraries is giving me trouble; I am able to link correctly to the includes, but there are undefined references errors thrown when I don't do linking, and when I attempt linking, it throws errors. This is my current CMakeLists.txt file:
# CMakeList.txt : CMake project for ANT, include source and define
# project specific logic h"ere.
#
cmake_minimum_required (VERSION 3.8)
project ("ANT")
link_directories(${ANT_SOURCE_DIR}/xscommon xscontroller xstypes)
add_executable(
ANT
"ANT.cpp"
"ANT.h"
"quaternionic.h"
"stars.h"
"hashes.h"
)
target_include_directories(ANT PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
target_link_libraries(ANT PUBLIC xscommon_config)
When I run this, the builder says the following:
/usr/bin/ld: cannot find -lxscommon_config
I need to look for these libraries in the directory that ANT.cpp is in, as this is where they are kept, however nothing I do (and I have messed around with configurations for hours now) will tell camke to look for these libraries in the src folder. it always goes to /usr/bin/ld.
I really just need to know what to tell CMake such that it will look in the correct place for each file, that is if I am telling it to look for the correct file (I am fairly sure I am).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Update
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
So I have remade the CMakeLists.txt file to this:
# CMakeList.txt : CMake project for ANT, include source and define
# project specific logic here.
#
cmake_minimum_required (VERSION 3.15)
project ("ANT")
#[STATIC | SHARED | MODULE]
#[STATIC | SHARED | MODULE]
#[STATIC | SHARED | MODULE]
add_library(xscommon SHARED IMPORTED)
add_library(xscontroller SHARED IMPORTED)
add_library(xstypes SHARED IMPORTED)
add_executable(
ANT
"ANT.cpp"
"ANT.h"
)
target_include_directories(ANT PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
And still get undefined references. I am going to try building the libraries instead. Additionally, I have contacted the manufacturer of the IMUs which use this SDK, as colleagues have not been able to fix this either.
The problem is you are linking to a library that has not been build.
This
# link to this directory
target_link_libraries(ANT PRIVATE xscommon)
tries to link to a library called xscommon to the target ANT but you have not build xscommon anywhere in your project.
If xscommon is a pre-build library and you just want to import it then add the library and set the IMPORTED target property:
add_library(xscommon [STATIC | SHARED | MODULE] IMPORTED)
If you want to build xscommon in your root CMakeLists.txt. Add xscommon as a library and include the location of the headers.
add_library(xscommon [STATIC | SHARED | MODULE]
xxx/xxx.cpp #list all source files that build the library - use relative path
)
target_include_directories(xscommon PRIVATE
xxx/xxx #path to the location of library header files
)
Also you don't need to add the header files when adding the executable. So this
add_executable(
ANT
"ANT.cpp"
"ANT.h"
"quaternionic.h"
"stars.h"
"hashes.h"
)
can be simplified to
add_executable(
ANT
"ANT.cpp"
)
Suppose your dir is like this:
ANT
-xscommon
--xscommon_config.h
--xscommon_config.cpp
...
First add a CMakeLists.txt file to xscommon/:
ANT
-xscommon
--CMakeLists.txt
--xscommon_config.h
--xscommon_config.cpp
...
Now in xscommon/CMakeLists.txt we will create a library, that will be imported and linked in the main CMakeLists.txt file:
xscommon/CMakeLists.txt:
#define another target, let's name it 'xscommon'
add_library(xscommon
xscommon_config.h
xscommon_config.cpp
#more sources if you want
)
Now in the main CMakeLists.txt file:
cmake_minimum_required (VERSION 3.8)
project ("ANT")
#remove this line
#link_directories(${ANT_SOURCE_DIR}/xscommon xscontroller xstypes)
add_executable(
ANT
"ANT.cpp"
"ANT.h"
"quaternionic.h"
"stars.h"
"hashes.h"
)
# add the xscommon directory, this will make the library target defined there available here
add_subdirectory(xscommon)
# link to this directory
target_link_libraries(ANT PRIVATE xscommon)
# use PUBLIC if the xscommon library will be part of the public interface of your
# library. But since it is an executable, PRIVATE is better here.
target_include_directories(ANT PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
Use the above method, you can create more libraries and link to them.
Note that it is not necessary to create separate cmake files for each subdirectory but it is considered a good practice and modularizes your code. If you want to do this in the main cmake file instead of creating a subdirectory, add this to the main cmake:
add_library(xscommon
xscommon/xscommon_config.h
xscommon/xscommon_config.cpp
#more sources if you want
)
Update according to the changes in question
Your current CMakeLists.txt:
These three lines below are not doing anything, definitely not what you think. add_library() command has the word "add" in it, I know, but it doesn't add any library, just like add_executable doesn't add any executable. It creates a library.
add_library(xscommon SHARED IMPORTED)
add_library(xscontroller SHARED IMPORTED)
add_library(xstypes SHARED IMPORTED)
How to create a library in cmake out of two file a.cpp and a.h:
add_library(myALib "a.cpp")
That's it. If you have more sources, you will include them accordingly of course. In your case you will have to add the sources of xscommon and others accordingly.
Once you have created the libraries, you need to link them to your executable. If you won't you will get undefined reference errors because compiler can locate the declarations in header files but not the definitions of your code which exists in .cpp files.
So, how do you link? Simple:
target_link_libraries(TARGET_NAME PUBLIC | PRIVATE LIBRARY_NAME)
# TARGET_NAME: can be `executable` or `library`
# PUBLIC or PRIVATE (for exe, it is usually private)
# LIBRARY_NAME: Name of library you want to link to TARGET_NAME
# So if you wanted to link "myALib" which I created above to ANT, you would do:
target_link_libraries(ANT PRIVATE myALib)
# Note: You need to add this line **after** add_executable() because target "ANT" will be created after that. You can do the linking after the "target_include_directories" command.
I have two Proto files across two different folders and am trying to use CMake for building the overall project.
protofile1 has protofile2 as it's dependency.
Library1 has protofile1 as it's dependency which I can generate using protobuf_generate_cpp.
But for generating protofile1, I have protofile2 as it's dependency. How do I do this using CMake?
How do I compile proto file and make it available as a library using CMake (in folder2)?
Folder Structure:
|
|-folder1
---|-protofile1.proto
---|-library1.cc
|-folder2
---|-protofile2.proto
---|-library2.cc
CMakeLists.txt for folder1
cmake_minimum_required(VERSION 3.3)
find_package(Protobuf REQUIRED)
protobuf_generate_cpp(protofile1_cc protofile1_header protofile1.proto)
target_link_libraries(protofile1_cc INTERFACE protofile2_lib) # is this correct?
add_library(library1 INTERFACE)
target_sources(library1 INTERFACE library1.cc)
target_link_libraries(library1 INTERFACE protofile1_cc)
CMakeLists.txt for folder2
cmake_minimum_required(VERSION 3.3)
find_package(Protobuf REQUIRED)
# don't know how to do this
add_library(protofile2_lib INTERFACE) # is this correct?
target_sources(protofile2_lib INTERFACE protofile2.proto) # is this correct?
The protobuf_generate_cpp command does not define targets, but it defines CMake variables referring to the auto-generated source files (.cc, .h). These variables should be used to define your targets via add_library(). You are on the right track, but your CMakeLists.txt file in folder2 should also call protobuf_generate_cpp to process protofile2.proto as well.
Also, if you're using CMake to build both, the top-level CMake (in the parent folder to folder1 and folder2) can find Protobuf so you don't have to find it twice. Something like this should get you closer to the desired solution:
CMakeLists.txt (top-level):
cmake_minimum_required(VERSION 3.3)
find_package(Protobuf REQUIRED)
add_subdirectory(folder2)
add_subdirectory(folder1)
folder2/CMakeLists.txt
# Auto-generate the source files for protofile2.
protobuf_generate_cpp(protofile2_cc protofile2_header protofile2.proto)
# Use the CMake variables to add the generated source to the new library.
add_library(protofile2_lib SHARED ${protofile2_cc} ${protofile2_header})
# Link the protobuf libraries to this new library.
target_link_libraries(protofile2_lib PUBLIC ${Protobuf_LIBRARIES})
folder1/CMakeLists.txt
# Auto-generate the source files for protofile1.
protobuf_generate_cpp(protofile1_cc protofile1_header protofile1.proto)
# Use the CMake variables to add the generated source to the new library.
add_library(library1 SHARED ${protofile1_cc} ${protofile1_header})
# Link proto2 library to library1.
target_link_libraries(library1 INTERFACE protofile2_lib)
My C++ project has a dependency to a library, that I have the source for in a subdirectory. This external library has an option 'build_static_lib' for building it as a static library in its CMakeLists.txt file.
In my top directory CMakeLists.txt, my understanding is that this should be simple:
add_executable(myproject ${SOURCES})
set(build_static_lib ON)
add_subdirectory(${CMAKE_SOURCE_DIR}/subdirectory/external_project)
unset(build_static_lib)
....
target_link_libraries(myproject PRIVATE externalproject another_library)
When I run this, my sources are built, then during the make, I am given an error that it cannot find -lexternalproject.
The strange thing is, when I change CMakeLists.txt (or delete the CMakeCache), and run it again, suddenly it successfully builds the libexternalproject and links it correctly.
Am I missing something? My journey with CMake has been unbelievably painful and any suggestions would be appreciated. It seems like every online resource has a very different strategy, and none of them quite achieve this presumably simple case. Thanks!
EDIT:
The content of the external project's CMakeLists.txt is https://github.com/muflihun/easyloggingpp/blob/master/CMakeLists.txt:
if (build_static_lib)
if (lib_utc_datetime)
add_definitions(-DELPP_UTC_DATETIME)
endif()
require_cpp11()
add_library(easyloggingpp STATIC src/easylogging++.cc)
install(TARGETS
easyloggingpp
ARCHIVE DESTINATION lib)
endif()