In many cmake find modules, we find INCLUDE("${CMAKE_CURRENT_LIST_DIR}/FindPackageHandleStandardArgs.cmake")
I would like to do the same thing but from the CMakeLists of my project.
The problem is that ${CMAKE_CURRENT_LIST_DIR} is pointing to the directory of my project... And FindPackageHandleStandardArgs.cmake is in /usr/share/cmake-2.8/Modules/.
Is there a CMake variable that is pointing to the cmake module directory ?
If not, how to do that in my CMakeLists (I want that to be portable and not to be "hardcoded") ?
Thank you very much.
If a module file is specified, the include command will search the CMake module directory automatically. Just use:
include(FindPackageHandleStandardArgs)
If you've changed the CMAKE_MODULE_PATH variable (which is usually the case when creating a custom Find*.cmake), you can do:
include(${CMAKE_ROOT}/Modules/FindPackageHandleStandardArgs)
Related
I have a cmake project which one of the install targets is a collection of files. This files change depending on the configuration (Release, Debug...).
I would like to be able to install the files like so:
install(DIRECTORY $<TARGET_FILE_DIR:tgt>
DESTINATION bin
COMPONENT files)
But cmake does not support that. Generator variables do not apply to DIRECTORY. So I was wondering if there is a way to either save the directory somewhere. Either the cache or a file and then load it into cpack.
So I guess the question is how to pass a variable from cmake to cpack?
This is a rather late answer, but I happened upon this question trying to solve a somewhat different problem that could also be summarized as: "How do I pass a variable to CPack?" In my case, I was making this call from a customized version of CPackDeb.cmake copied to my workspace:
find_program(OPKG_CMD NAMES opkg-build HINTS "${OPKG_HINT}")
# ^^^^^^^^^^^^
# This is what I wanted to pass to CPack
I was setting OPKG_HINT in a file included from my top-level CMakeLists.txt, but it was not getting passed through to cpack; the above find_program() invocation was seeing an empty string for OPKG_HINT.
The solution turned out to be stupid simple: just prepend CPACK_ to the variable name!
If I do this in CMakeLists.txt:
set(CPACK_OPKG_HINT "${_sysroot_top}/aarch64-poky-linux/usr/bin")
then I can put this in my CPackDeb.cmake file and it works fine:
find_program(OPKG_CMD NAMES opkg-build HINTS "${CPACK_OPKG_HINT}")
Anyway, this wound up being a bit of an X-Y problem for the OP, but... if you really need to set a variable at CMake time in such a way that it's accessible to cpack, prefixing the variable name with CPACK_ seems to do the trick nicely...
The following setup work if you use a "single-configuration generators (such as make and Ninja)" and call CMake with
cmake -DCMAKE_BUILD_TYPE=Release <source_dir>
https://cmake.org/cmake/help/v3.0/variable/CMAKE_BUILD_TYPE.html
You can define the ${dir} variable in another way if you like.
IF (CMAKE_BUILD_TYPE STREQUAL "Release")
SET(dir release_dir)
ELSE()
SET(dir debug_dir)
ENDIF()
INSTALL(DIRECTORY ${dir} DESTINATION bin COMPONENT files)
Until now this seems to be the best answer (from someone on the cmake mail list)
install(DIRECTORY path/to/Debug/dir
DESTINATION bin
CONFIGURATIONS Debug
COMPONENT files
)
install(DIRECTORY path/to/Release/dir
DESTINATION bin
CONFIGURATIONS Release
COMPONENT files
)
CMake 3.5 supports generator expressions for the DIRECTORY arguments. See installing directories.
For external libraries the user can specify a non-standard location by adding the path to the CMAKE_FLAGS or by adding -DMYLIB_ROOT. Within the CMake script I want to find the library's pkg-config pc file. Because the pc file is not in the standard folder, it is not found by pkg-config with FindPkgConfig's pkg_search_module.
I tried to add the user-given path to the PKG_CONFIG_PATH but it seemed to be ignored:
include(FindPkgConfig)
set(PKG_CONFIG_PATH "${PKG_CONFIG_PATH}:${MYLIB_ROOT}/lib/pkgconfig")
pkg_search_module(PKG_MYLIB mylib)
if(${PKG_MYLIB_FOUND})
...
When I call pkg-config from the terminal with the modified PKG_CONFIG_PATH set, it find the pc file. What am I doing wrong? How can I get pkg_search_module working? I'd like to avoid calling pkg-config directly from CMake.
Maybe the following will do the job
set( ENV{PKG_CONFIG_PATH} "$ENV{PKG_CONFIG_PATH}:${MYLIB_ROOT}/lib/pkgconfig" )
This is a known issue and a ticket exists in CMake's bugtracker, but it is backlocked due to lack of developer interest. I guess one has to provide a patch first...
Edit: According to the bugtracker the feature has been implemented and is part of CMake 3.1.
I have found in library Poco under contrib a PocoConfig.cmake which I've copied under /cmake/Modules
I also added in my CMakeLists.txt:
set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake/Modules/")
Now I run under /Build/cmake ..
And I keep getting:
CMake Error at CMakeLists.txt:41 (find_package):
By not providing "FindPoco.cmake" in CMAKE_MODULE_PATH this project has
asked CMake to find a package configuration file provided by "Poco", but
CMake did not find one.
Could not find a package configuration file provided by "Poco" with any of
the following names:
PocoConfig.cmake
poco-config.cmake
Add the installation prefix of "Poco" to CMAKE_PREFIX_PATH or set
"Poco_DIR" to a directory containing one of the above files. If "Poco"
provides a separate development package or SDK, be sure it has been
installed.
Obviously CMake is not finding the module file. What am I doing wrong, how to explicitly point CMake to that module file?
The PocoConfig.cmake doesn't works with find_package (otherwise, it would be named FindPoco.cmake), that's why you're getting this error.
Just include the PocoConfig.cmake in your CMakeLists.txt with:
include(${CMAKE_SOURCE_DIR}/cmake/Modules/PocoConfig.cmake)
I've had similar issues. In my case I was recompiling with an old build folder in place - deleting the folder and recompiling worked.
I installed Ogre3D 1.8.1 (the source package) on Ubuntu 12.04 and everything went fine (I managed to run some samples on the Ogre interface). However, I hit a problem while I was compiling an external project (that one) that needed the OpenCV, ArUco and Ogre librarys. When I run the CMake of the project, I receive the following:
CMake Error at CMakeLists.txt:46 (find_package):
By not providing "FindOGRE.cmake" in CMAKE_MODULE_PATH this project has
asked CMake to find a package configuration file provided by "OGRE", but
CMake did not find one.
Could not find a package configuration file provided by "OGRE" with any of
the following names:
OGREConfig.cmake
ogre-config.cmake
Add the installation prefix of "OGRE" to CMAKE_PREFIX_PATH or set
"OGRE_DIR" to a directory containing one of the above files. If "OGRE"
provides a separate development package or SDK, be sure it has been
installed.
-- Configuring incomplete, errors occurred!
I know where the FindOGRE.cmake is, it's in the /usr/local/lib/OGRE/cmake, but I don't know how to say to CMake to look for that folder and fix this problem.
You just need to use the -D command line option along with the CMAKE_MODULE_PATH variable:
cmake . -DCMAKE_MODULE_PATH=/usr/local/lib/OGRE/cmake
Just for the record, an alternative solution would be to add the module path directly in the CMakeLists.txt. For example (tested on Debian 9):
set(CMAKE_MODULE_PATH "/usr/share/OGRE/cmake/modules/;${CMAKE_MODULE_PATH}")
Just make sure to add the line before find_package is called.
For me, it only works to set the following in CMakeLists.txt before find_package:
set(OGRE_DIR /usr/share/OGRE/build/sdk/CMake)
Note that the CMake directory is the one containing OGREConfig.cmake. For some reason, my CMake ignores CMAKE_MODULE_PATH.
Maybe, of some help for someone
For me, this solution work on manjaro:
set(CMAKE_MODULE_PATH "/usr/lib/OGRE/cmake;${CMAKE_MODULE_PATH}")
find_package(OGRE QUIET)
if (OGRE_FOUND)
include_directories( ${ogre_INCLUDE_DIR})
link_directories(${OGRE_LIBRARIES})
message(STATUS "OGRE: FOUND")
else()
message(STATUS "OGRE: NOT FOUND")
endif()
CMake cannot find my Eigen3 package. I set an environment variable called
EIGEN3_INCLUDE_DIR
pointing to the path where FindEigen3.cmake is.
Then in the CMakelists.txt I wrote:
find_package( Eigen3 REQUIRED )
include_directories( EIGEN3_INCLUDE_DIR )
I get next message of error:
CMake Error at C:/Program Files (x86)/CMake 2.8/share/cmake-2.8/Modules/FindPackageHandleStandardArgs.cmake:91 (MESSAGE):
Could NOT find Eigen3 (missing: EIGEN3_INCLUDE_DIR EIGEN3_VERSION_OK)
(Required is at least version "2.91.0")
Call Stack (most recent call first):
C:/Program Files (x86)/CMake 2.8/share/cmake-2.8/Modules/FindPackageHandleStandardArgs.cmake:252 (_FPHSA_FAILURE_MESSAGE)
C:/Program Files (x86)/CMake 2.8/share/cmake-2.8/Modules/FindEigen3.cmake:76 (find_package_handle_standard_args)
test/test_quaternion/CMakeLists.txt:25 (find_package)
Any idea on what I am missing or doing wrong?
Since Eigen3 is completely header only, all you ever need is the path to the include directory. And this one, you are already defining manually anyway. So there is no real need for a FindEigen3.cmake or FIND_PACKAGE call.
Simply use
INCLUDE_DIRECTORIES ( "$ENV{EIGEN3_INCLUDE_DIR}" )
or
SET( EIGEN3_INCLUDE_DIR "$ENV{EIGEN3_INCLUDE_DIR}" )
IF( NOT EIGEN3_INCLUDE_DIR )
MESSAGE( FATAL_ERROR "Please point the environment variable EIGEN3_INCLUDE_DIR to the include directory of your Eigen3 installation.")
ENDIF()
INCLUDE_DIRECTORIES ( "${EIGEN3_INCLUDE_DIR}" )
A few notes:
If you want to access the content of a CMake variable, make sure to use ${...}
$ENV{....} accesses environment variables.
The second example will stop with an error if the environment variable is not set (and, thus, EIGEN3_INCLUDE_DIR cmake variable is empty)
Be careful to use quotation marks around (evaluated) variables if they could contain whitespace. Otherwise, CMake will interpret it as a list.
If you want to use custom find modules, make sure to either place them in you CMake installation or, as #Fraser pointed out above, make sure to point CMAKE_MODULE_PATH to the directory where it is. Not sure, but it could be that CMake checks the current directory as well automatically (where your CMakeLists.txt resides. Anyhow, setting EIGEN3_INCLUDE_DIR is totally unrelated to the location of FindEigen3.cmake
However, it could be that your FindEigen3 script evaluates this variable to determine the location of your Eigen3 installation.
Alternatively, self-built CMake-based projects often provide a <PackageName>Config.cmake. If you point a variable called <PackageName>_DIR to the directory containing this file, you can use FIND_PACKAGE( <PackageName> ...) as normal. See documentation of FIND_PACKAGE for details.
Eigen >= 3.3 has direct CMake integration, so it seems yours isn't set up correctly.
Assume Eigen has been installed to /opt/eigen/3.3 with default settings. Append or prepend the the location /opt/eigen/3.3 to the environment variable CMAKE_PREFIX_PATH e.g in bash:
export CMAKE_PREFIX_PATH="$CMAKE_PREFIX_PATH:/opt/eigen/3.3"
Then CMake should pick it up.
If you are writing your own CMakeLists.txt that uses Eigen I suggest using code like this:
find_package (Eigen3 3.3 REQUIRED)
add_executable (example example.cpp)
target_link_libraries (example Eigen3::Eigen)
You should not use include_directories since CMake 3 was released -- the targets approach should be preferred whenever available.
First, make sure Eigen is properly installed. Refer to the INSTALL file that comes with the tarball.
Second, copy the cmake/FindEigen3.cmake file from the tarball to the directory containing your CMakeLists.txt.
In your CMakeLists.txt add:
set(CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR})
find_package(Eigen3 REQUIRED)
include_directories(${EIGEN3_INCLUDE_DIR})
Now you should be able to do e.g. #include <Eigen/Core>.
All of this comes (mostly) from this source.
This approach has the advantage over e.g. include_directories("$ENV{EIGEN3_INCLUDE_DIR}") that it the uses CMake's standard mechanism for finding external dependencies, making it easier for someone else (or your future self) to pick up the project, possibly on another platform.
(However, it would be nice if Eigen itself installed an EigenConfig.cmake file, making it accessible through the find_package mechanism without any extra paths.)
I found another solution here (which referred to here) which uses the pkg-config file :
find_package(PkgConfig)
pkg_search_module(Eigen3 REQUIRED eigen3)
As a detailed explanation of the note 7 from the top answer of Johannes. By using the "Config mode" rather than "Module mode" of CMake find_packate(), only writing
find_package( Eigen3 REQUIRED )
include_directories( EIGEN3_INCLUDE_DIR )
in CMakeLists.txt is enough.
Please refer to the INSTALL guidance text file contained in the eigen source code directory (eg. extracted from eigen-3.3.7.tar.gz downloaded from official website), which said:
Method 2. Installing using CMake
********************************
Let's call this directory 'source_dir' (where this INSTALL file is).
Before starting, create another directory which we will call 'build_dir'.
Do:
cd build_dir
cmake source_dir
make install
The "make install" step may require administrator privileges.
You can adjust the installation destination (the "prefix")
by passing the -DCMAKE_INSTALL_PREFIX=myprefix option to cmake, as is
explained in the message that cmake prints at the end.
Just like installing usual CMake projects to your machine.
The difference from directly including the /usr/include/eigne3 or /usr/local/include/eigen3 directory is that, a configuration directory called eigen3/cmake will also be installed to /usr/share or usr/local/share. This configuration directory contains the Eigen3Config.cmake file, which can automatically be found by CMake to locate the eigen3 directory.
If you have not added Eigen Library to environment variable then do the following in CMakeLists.txt:
cmake_minimum_required(VERSION 3.9)
project(ProjectName)
set(CMAKE_CXX_STANDARD 11)
# set EIGEN_DIR variable to Eigen Library Path
set(EIGEN_DIR "C:\\Eigendir\\Eigen")
# include the directory
include_directories(${EIGEN_DIR})
add_executable(ProjectName main.cpp)
target_link_libraries(ProjectName ${EIGEN_DIR})
Another simple way that doesn't require adding an environment variable is to simply find eigen with the cmake find_path function https://cmake.org/cmake/help/v3.6/command/find_path.html. The example code finds the directory "Eigen" in paths "/usr/include/" and "/usr/local/include" with an additional search in subdirectory "eigen3".
find_path(EIGEN3_INCLUDE_DIRS "Eigen" paths "/usr/include" "/usr/local/include" path_suffixes "eigen3")
message(${EIGEN3_INCLUDE_DIRS})
if ( NOT EIGEN3_INCLUDE_DIRS )
message(FATAL_ERROR "CMake variable EIGEN3_INCLUDE_DIRS not found.")
endif()
include_directories ( "${EIGEN3_INCLUDE_DIRS}" )
You could try setting the CMAKE_MODULE_PATH to the location of Eigen subdirectory named "cmake":
cmake . -DCMAKE_MODULE_PATH=<Eigen root dir>/cmake/
I had a similar problem when run cmake .. && make on Google Colab on a project clone from github. I fixed it by editing CMakeLists.txt file and adding this line to it:
set(EIGEN3_INCLUDE_DIR "/usr/include/eigen3")
As you can see, my eigen3 was in /usr/include/eigen3 path (and I had installed it using !sudo apt-get install build-essential cmake libeigen3-dev)
When installing on Kubuntu 20.04 following steps from INSTALL:
Do:
cd build_dir
cmake source_dir
make install
using -DCMAKE_INSTALL_PREFIX=/usr/local/eigen-3.4.0 and sudo
FindEigen3.cmake is not installed. However, using
set(Eigen3_DIR "/usr/local/eigen/share/eigen3/cmake")
seem to work. FindEigen3.cmake is in the build directory
but it is not copied to the installation directory tree.
This worked:
Changed c++11 to c++14
Changed find_package(Eigen3 QUIET) to find_package(Eigen3 CONFIG)
Another simple way is:
if the Eigen library is in /opt/eigen/3.3/Eigen
include_directories(/opt/eigen/3.3)
which is equivalent to what Jai suggested
set(EIGEN_DIR "/opt/eigen/3.3")
include_directories(${EIGEN_DIR})
You need to read official documentation:
Click here
After install Eigen from tar and compile it correctly.
CMakeLists.txt will looks like this:
find_package(Eigen3 3.3 REQUIRED NO_MODULE)
add_executable(${PROJECT_NAME} something.cpp)
target_link_libraries(${PROJECT_NAME} Eigen3::Eigen)
It will be fine work.