Is it possible to get CMake to gather up all the package libraries used during compilation, recursively grab their required libraries, and then put them all in a single directory?
As an example if my application requires gtk it would grab glib and its required libraries libiconv, gettext, and libffi.
You can use the GetPrerequesites CMake module.
See here for more information
Related
My cmake project builds against external libraries, e.g. Boost. I would now like to advise cmake to generate "make install code" that causes all used external libraries to be added to the installation package.
My hope is that cmake can inspect the built shared objects and executables, e.g. using ldd, to find out which external libraries are required and add them without explicit naming of the individual libraries in the CMakeLists.txt.
Of course there is the other case in which the built code expicitly loads the external libaries (dlopen(), ...), e.g. as done by Intel IPP. In this case I would probably somehow need to explicitly name the libraries to install, e.g. using some variables set by the FindXXX cmake scripts.
I am working on a larger C++ library that is using CMake and depends on Qt.
We moved from Qt4 to Qt5 and now I encounter a problem when using our lib
in an upstream project. As a minimal working example demonstrating the problem please have a look at this repo:
https://github.com/philthiel/cmake_qt5_upstream
It contains two separate CMake projects:
MyLIB: a tiny library that uses QString from Qt5::Core.
It generates and installs package configuration files
MyLIBConfig.cmake, MyLIBConfigVersion.cmake, and MyLIBTargets.cmake
in order to be searchable by CMake find_package()
MyAPP: a tiny executable depending on MyLIB
The project uses find_package(MyLIB) and creates an executable that uses MyLIB
The problem is that CMake gives me the following error message when configuring the MyAPP project:
CMake Error at CMakeLists.txt:11 (add_executable):
Target "MyAPP" links to target "Qt5::Core" but the target was not found.
Perhaps a find_package() call is missing for an IMPORTED target, or an
ALIAS target is missing?
The reason for this behaviour is that in the automatically generated MyLIBTargets.cmake file the INTERFACE_LINK_LIBRARIES entry for Qt5 Core is the Qt5::Core symbol. Using Qt4, the absolute path to the Qt core lib was specified here.
Now, I simply can resolve this by using
find_package(Qt5Core 5.X REQUIRED)
in the MyAPP project.
However, I would like to know if this is the intended/generic way to go, i.e. requesting upstream projects of our lib to search for the required transitive Qt5 dependencies themselves, or if I probably misuse CMake here and need to change my configuration procedure?
The CMake docu on package file generation
https://cmake.org/cmake/help/v3.0/manual/cmake-packages.7.html
mentions that macros can be provided by the package configuration files to upstream. Maybe this would be the correct place to search for imported targets like Qt5 and break upstream configuration runs when these dependencies are not found?
Best,
Philipp
[edit of the edit] Full Source Example
You need to deliver a CMake config file for your project, and probably the ConfigFile should be generated via CMake itself (because you cannot know for shure where the user will install your software).
Tip, use the ECM cmake modules to ease the creation of that:
find_package(ECM REQUIRED NO_MODULE)
include(CMakePackageConfigHelpers)
ecm_setup_version(${PROJECT_VERSION}
VARIABLE_PREFIX ATCORE
VERSION_HEADER "${CMAKE_CURRENT_BINARY_DIR}/atcore_version.h"
PACKAGE_VERSION_FILE "${CMAKE_CURRENT_BINARY_DIR}/KF5AtCoreConfigVersion.cmake"
SOVERSION 1
)
configure_package_config_file("${CMAKE_CURRENT_SOURCE_DIR}/KF5AtCoreConfig.cmake.in"
"${CMAKE_CURRENT_BINARY_DIR}/KF5AtCoreConfig.cmake"
INSTALL_DESTINATION ${CMAKECONFIG_INSTALL_DIR}
)
and the KF5AtCoreConfig.cmake.in:
#PACKAGE_INIT#
find_dependency(Qt5Widgets "#REQUIRED_QT_VERSION#")
find_dependency(Qt5SerialPort "#REQUIRED_QT_VERSION#")
find_dependency(KF5Solid "#KF5_DEP_VERSION#")
include("${CMAKE_CURRENT_LIST_DIR}/KF5AtCoreTargets.cmake")
This will generate the correct FindYourSortware.cmake with all your dependencies.
[edit] Better explanation on what's going on.
If you are providing a library that will use Qt, and that would also need to find the Qt5 library before compilling the user's source, you need to provide yourself a FindYourLibrary.cmake code, that would call
find_package(Qt5 REQUIRED COMPONENTS Core Gui Widgets Whatever)
Now, if it's your executable that needs to be linked, use the Components instead of the way you are doing it now.
find_package(Qt5 REQUIRED COMPONENTS Core)
then you link your library with
target_link_libraries(YourTarget Qt5::Core)
Once CMake has successfully built an executable which requires some shared libraries, by using 'ldd', we can easily get the list of shared library dependencies and where we can find them.
For instance, libstdc++ is here: /usr/lib64/libstdc++.so.6
Now we want to make a package (e.g. a .tgz package), we need to include those shared libraries with no doubt.
We can do:
set(DEPENDENCIES /usr/lib64/libstdc++.so.6 /usr/lib64/[libname2] /usr/lib64/[libname3])
foreach(DEPENDENCY ${DEPENDENCIES})
install(PROGRAMS "${DEPENDENCY}" DESTINATION lib)
endforeach()
Is there a smarter way to achieve the same purpose?
Instead of manually specifying path to all libraries, can we make it an automatic process? Given CMake already knows all the dependencies and the according library path in the link stage, should it be straightforward?
I use find_package to include external library into my CMake project. Because I wanted to add support for static linking, I set set(BUILD_SHARED_LIBS FALSE). However, I still get libraries like libglew32.dll.a which are just wrappers that make dynamic linking easier. Instead, I want CMake to find libglew32.a which exists in the same directory. This is the module to find GLEW I use.
You can always link to an exact library using the filename. Here are the flags you would use
-l:[filename]
For cmake
target_link_libraries(target :libglew32.a)
Doing this on linux will use all static libraries
set(CMAKE_FIND_LIBRARY_SUFFIXES .a ${CMAKE_FIND_LIBRARY_SUFFIXES})
if you are building external libraries, usually i just include them in my target
target_link_libraries(myprogram
${LIBROCKET_LIBS_DIRS}/libRocketCore.a
${LIBROCKET_LIBS_DIRS}/libRocketControls.a)
I'm trying to make a small game using both SFML and Box2D. I have the following directory structure:
/
src/
game/ # my code
thirdparty/ # other libraries' code
box2d/
sfml/
bin/
etc...
I'm trying to set it up so that I can run make and have box2d or sfml compile as well if they need, since I might make some changes to the libraries.
I've tried putting this in my CMkaeLists.txt:
find_package(Box2D)
find_package(sfml-window)
find_package(sfml-graphics)
find_package(sfml-system)
as well as other things, but I keep getting errors and I'm not sure how to get around them. for example:
CMake Error at CMakeLists.txt:20 (find_package):
Could not find module Findsfml-window.cmake or a configuration file for
package sfml-window.
Adjust CMAKE_MODULE_PATH to find Findsfml-window.cmake or set
sfml-window_DIR to the directory containing a CMake configuration file for
sfml-window. The file will have one of the following names:
sfml-windowConfig.cmake
sfml-window-config.cmake
But I can't find any of the files it lists there.
The find_pacakge command is for finding packages that are defined in for cmake as modules or configurations. There is probably not a cmake module or config defined for these libraries. So, if you want to use the find package command to find these libraries then you will need to create a cmake module that knows how to find them. Given your stated requirements I would not think that this is easiest way to do it.
If you are statically linking you libraries then set up a custom target to invoke make on each of the libraries. Add the include directories to your include path. Use find_library command to find the libraries.
If you intend to dynamically link your libraries then create a custom target to build and install your libraries and you should be good as long as you install them in one of the normal places.
Have a gander here:
http://www.itk.org/Wiki/CMake:How_To_Find_Libraries Writing find modules
Take a look at the "Writing find modules" section. Be sure to read the document all the way through.
If you want to make redistributable and portable cmake projects, I think this is the right direction for you to go.