CMake install: installing configuration files - cmake

I want CMake to make install rules for me which also automatically install configuration and other things. I looked at this question, but adding:
add_executable(solshare_stats.conf solshare_stats.conf)
to my CMakeLists.txt file only gave me warnings and errors:
CMake Error: CMake can not determine linker language for target:solshare_stats.conf
CMake Error: Cannot determine link language for target "solshare_stats.conf".
...
make[2]: *** No rule to make target `CMakeFiles/solshare_stats.conf.dir/build'. Stop.
make[1]: *** [CMakeFiles/solshare_stats.conf.dir/all] Error 2
make: *** [all] Error 2
How do I add configuration, init and/or logfiles to CMake install rules?
Here is my complete CMakeLists.txt file:
project(solshare_stats)
cmake_minimum_required(VERSION 2.8)
aux_source_directory(. SRC_LIST)
add_executable(${PROJECT_NAME} ${SRC_LIST} )
add_executable(solshare_stats.conf solshare_stats.conf)
target_link_libraries(solshare_stats mysqlcppconn)
target_link_libraries(solshare_stats wiringPi)
if(UNIX)
if(CMAKE_COMPILER_IS_GNUCXX)
SET(CMAKE_EXE_LINKER_FLAGS "-s")
SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -O2 -Wall -std=c++0x")
endif()
install(TARGETS solshare_stats DESTINATION /usr/bin COMPONENT binaries)
install(TARGETS solshare_stats.conf DESTINATION /etc/solshare_stats COMPONENT config)
endif()

The .conf file should be included in the add_executable where you define your executable target, not in a separate call:
add_executable(${PROJECT_NAME} ${SRC_LIST} solshare_stats.conf)
Then you need to use install(FILE ...) rather than install(TARGET ...):
install(TARGETS solshare_stats DESTINATION /usr/bin COMPONENT binaries)
install(FILES solshare_stats.conf DESTINATION etc/solshare_stats COMPONENT config)
By doing
add_executable(${PROJECT_NAME} ${SRC_LIST})
add_executable(solshare_stats.conf solshare_stats.conf)
you're saying you want to create 2 executables, one called "solshare_stats" and another called "solshare_stats.conf".
The second target's only source file is the actual file "solshare_stats.conf". Since none of the source files in this target have a suffix which gives an idea about the language (e.g ".cc" or ".cpp" implies C++, ".asm" implies assembler), no language can be deduced, hence the CMake error.

Related

CMake having multiple executables throws me an error

I'm having some trouble with cmake: I'm using cmake for my school project and there is a bonus part but we have to compile another executable for the bonus part, and I tried this:
cmake_minimum_required(VERSION 3.10)
project(philosophers)
set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
set(CMAKE_C_COMPILER /usr/bin/clang)
set(CMAKE_C_STANDARD 99)
set(CMAKE_C_FLAGS "-Wall -Wextra -Werror")
set(CMAKE_EXE_LINKER_FLAGS "-lpthread")
set(LIBFT ${CMAKE_CURRENT_SOURCE_DIR}/lib/libft42/libft.a)
add_custom_command(OUTPUT ${LIBFT}
COMMAND make
WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/lib/libft42)
link_libraries(philo_bonus ${LIBFT})
link_libraries(philo ${LIBFT})
aux_source_directory(src SRC)
aux_source_directory(src_bonus SRC_BONUS)
add_executable(philo ${SRC} ${LIBFT})
add_executable(philo_bonus ${SRC_BONUS} ${LIBFT})
target_include_directories(philo
PUBLIC inc
PUBLIC lib/libft42/inc)
target_include_directories(philo_bonus
PUBLIC inc_bonus
PUBLIC lib/libft42/inc)
I removed include_directories and replaced it with target_include_directories because I want my two projects to have separate includes, but when I try to cmake -Bbuild -H., it says:
CMake Error at CMakeLists.txt:23 (add_executable):
Target "philo_bonus" links to itself.
CMake Error at CMakeLists.txt:22 (add_executable):
Target "philo" links to itself.
CMake Error: Cannot determine link language for target "philo_bonus".
CMake Error: CMake can not determine linker language for target: philo_bonus
-- Generating done
CMake Generate step failed. Build files cannot be regenerated correctly.
I don't understand what happened here, I changed nothing in add_executable and it worked fine before I added another.

cmake linker error with library installed in custom path

I have compiled and installed with CMake the library SDL_bgi to a custom prefix /custom/prefix/. This library uses SDL2.
Now I want to use it in another project with the structure below but I get a linker error when I compile with make:
/usr/bin/c++ CMakeFiles/test.dir/test.cpp.o -o test -Wl,-rpath,/custom/prefix/lib: /custom/prefix/lib/libSDL_bgi.so
/usr/bin/ld: /custom/prefix/lib/libSDL_bgi.so: undefined reference to `SDL_DestroyWindow'
/usr/bin/ld: /custom/prefix/lib/libSDL_bgi.so: undefined reference to `SDL_CreateRenderer'
I have also written the file cmake/modules/FindSDL_bgi.cmake so that may be wrong as well.
If I compile with the following command I can compile correctly:
g++ test.cpp -I . -lSDL_bgi -lSDL2 -I /custom/prefix/include/ -L /custom/prefix/lib/
What am I doing wrongly?
Project structure:
cmake/modules/FindSDL_bgi.cmake
src/test/CMakeLists.txt
src/test/test.cpp
CMakeLists.txt
Libraries:
/usr/lib/libSDL.so
/usr/include/SDL.h
/custom/prefix/lib/libSDL_bgi.so
/custom/prefix/include/graphics.h
/custom/prefix/include/SDL2/libSDL_bgi.h
cmake/modules/FindSDL_bgi.cmake:
# - Try to find LibXml2
# Once done this will define
# SDL_BGI_FOUND - System has LibXml2
# SDL_BGI_INCLUDE_DIRS - The LibXml2 include directories
# SDL_BGI_LIBRARIES - The libraries needed to use LibXml2
# Hardcoded for now
set(SDL_BGI_PATH
/custom/prefix/
)
set(SDL_BGI_SEARCH_PATHS
/usr
/usr/local
/opt
${SDL_BGI_PATH}
)
find_path(SDL_BGI_INCLUDE_DIR graphics.h
HINTS
$ENV{SDL2DIR}
PATH_SUFFIXES include
PATHS ${SDL2_SEARCH_PATHS}
)
find_library(SDL_BGI_LIBRARY
NAMES SDL_bgi
HINTS
$ENV{SDL2DIR}
PATH_SUFFIXES lib64 lib
PATHS ${SDL2_SEARCH_PATHS}
)
include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(SDL_bgi REQUIRED_VARS SDL_BGI_LIBRARY SDL_BGI_INCLUDE_DIR)
CMakeLists.txt
cmake_minimum_required(VERSION 3.15)
project(programmi_kennedy)
list(APPEND CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/cmake/modules")
set(COMPAT_HEADERS
${CMAKE_CURRENT_SOURCE_DIR}/include/
)
find_package(SDL_bgi REQUIRED)
add_subdirectory(src/test)
src/CMakeLists.txt:
add_executable(test test.cpp)
target_include_directories(test PUBLIC ${SDL_BGI_INCLUDE_DIR})
target_link_libraries(test PRIVATE ${SDL_BGI_LIBRARY})
install(TARGETS test DESTINATION bin)
/custom/prefix/include/graphics.h:
#include <SDL2/SDL_bgi.h>
What I was missing is to link to SDL2 with find_package(SDL2 REQUIRED) and link to SDL2::SDL2. (I did try to link to ${SDL2_LIBRARIES} but the syntax is different now). Thanks to #KamilCuk to point me to the right direction.
EDIT:
I changed the FindBGI_sdl.cmake module in order to search for the dependencies (SDL2) and link against them using the INTERFACE keyword. In this way the target test can link only against SDL_bgi and have the dependencies resolved automatically.
src/CMakeLists.txt:
add_executable(test test.cpp)
target_link_libraries(test PRIVATE SDL_bgi::SDL_bgi)
install(TARGETS test DESTINATION bin)
cmake/modules/FindSDL_bgi.cmake:
# Distributed under the OSI-approved BSD 3-Clause License. See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.
#[=======================================================================[.rst:
FindSDL_bgi
-------
Finds the SDL_bgi library.
Imported Targets
^^^^^^^^^^^^^^^^
This module provides the following imported targets, if found:
``SDL_bgi::SDL_bgi``
The SDL_bgi library
Result Variables
^^^^^^^^^^^^^^^^
This will define the following variables:
``SDL_bgi_FOUND``
True if the system has the SDL_bgi library.
``SDL_bgi_VERSION``
The version of the SDL_bgi library which was found.
``SDL_bgi_INCLUDE_DIRS``
Include directories needed to use SDL_bgi.
``SDL_bgi_LIBRARIES``
Libraries needed to link to SDL_bgi.
Cache Variables
^^^^^^^^^^^^^^^
The following cache variables may also be set:
``SDL_bgi_INCLUDE_DIR``
The directory containing ``foo.h``.
``SDL_bgi_LIBRARY``
The path to the SDL_bgi library.
#]=======================================================================]
find_package(SDL2 REQUIRED)
find_package(PkgConfig)
pkg_check_modules(PC_SDL_bgi QUIET SDL_bgi)
find_path(SDL_bgi_INCLUDE_DIR
NAMES graphics.h
PATHS ${PC_SDL_bgi_INCLUDE_DIRS}
)
find_library(SDL_bgi_LIBRARY
NAMES SDL_bgi
PATHS ${PC_SDL_bgi_LIBRARY_DIRS}
)
set(SDL_bgi_VERSION ${PC_SDL_bgi_VERSION})
include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(SDL_bgi
FOUND_VAR SDL_bgi_FOUND
REQUIRED_VARS
SDL_bgi_LIBRARY
SDL_bgi_INCLUDE_DIR
VERSION_VAR SDL_bgi_VERSION
)
if(SDL_bgi_FOUND AND NOT TARGET SDL_bgi::SDL_bgi)
add_library(SDL_bgi::SDL_bgi UNKNOWN IMPORTED)
set_target_properties(SDL_bgi::SDL_bgi PROPERTIES
IMPORTED_LOCATION "${SDL_bgi_LIBRARY}"
INTERFACE_COMPILE_OPTIONS "${PC_SDL_bgi_CFLAGS_OTHER}"
INTERFACE_INCLUDE_DIRECTORIES "${SDL_bgi_INCLUDE_DIR}"
)
target_link_libraries(SDL_bgi::SDL_bgi INTERFACE SDL2::SDL2)
endif()
mark_as_advanced(
SDL_bgi_INCLUDE_DIR
SDL_bgi_LIBRARY
SDL2_DIR
)
Useful references:
https://pabloariasal.github.io/2018/02/19/its-time-to-do-cmake-right/
https://cmake.org/cmake/help/v3.17/manual/cmake-developer.7.html

How to add Ziplib library in Clion on Ubuntu

I'm trying to add ZipLip into my project using Clion on ubuntu, but I have this output:
====================[ Build | TryZip | Debug ]==================================
/home/david/Snap/clion-2019.2.4/bin/cmake/linux/bin/cmake --build
/home/david/CLionProjects/TryZip/cmake-build-debug --target TryZip -- -j 2
[ 13%] Built target bzip2
[ 31%] Built target zlib
[ 83%] Built target lzma
[ 95%] Built target ZipLib
Scanning dependencies of target TryZip
[ 97%] Linking CXX executable ../bin/TryZip
/usr/bin/ld: cannot find -lExternalLibrary/ZipLib
collect2: error: ld returned 1 exit status
CMakeFiles/TryZip.dir/build.make:102: recipe for target '../bin/TryZip' failed
make[3]: *** [../bin/TryZip] Error 1
CMakeFiles/Makefile2:109: recipe for target 'CMakeFiles/TryZip.dir/all' failed
make[2]: *** [CMakeFiles/TryZip.dir/all] Error 2
CMakeFiles/Makefile2:116: recipe for target 'CMakeFiles/TryZip.dir/rule' failed
make[1]: *** [CMakeFiles/TryZip.dir/rule] Error 2
Makefile:131: recipe for target 'TryZip' failed
make: *** [TryZip] Error 2
This is my Cmakefile.txt
cmake_minimum_required(VERSION 3.15)
project(TryZip)
if(BOOST_FILESYSTEM)
include_directories(${BOOST_INCLUDE_DIR})
link_directories(${BOOST_LIB_DIR})
add_definitions(-DUSE_BOOST_FILESYSTEM)
else()
if(MSVC)
add_definitions(-DFILESYSTEM_EXPERIMENTAL)
endif()
endif()
if(BOOST_FILESYSTEM)
if(UNIX)
find_package(Boost COMPONENTS system filesystem REQUIRED)
target_link_libraries(${Boost_FILESYSTEM_LIBRARY}
${Boost_SYSTEM_LIBRARY})
endif()
endif()
add_subdirectory(ExternalLibrary/ZipLib)
link_libraries(ExternalLibrary/ZipLib)
include_directories(ExternalLibrary/ZipLib)
set(CMAKE_CXX_STANDARD 17)
add_executable(TryZip main.cpp ExternalLibrary/ZipLib/ZipFile.cpp)
target_link_libraries(TryZip ZipLib)
Can someone help me to solve this please?
My ZipLib folder is in the same folder as my cmakefile.txt file.
The call to link_libraries() appears to accept the wrong arguments in this case. The link_libraries() command takes arguments of existing CMake targets, or library names. It is also redundant with your target_link_libraries() call, as this already links ZipLib to TryZip.
Try removing the call to link_libraries(), as this CMake function is deprecated and its use is highly discouraged. The include_directories() call is similarly deprecated, in favor of the target-specific command, so consider using target_include_directories() instead.
Assuming your added sub-directory ExternalLibrary/ZipLib contains an additional CMakeLists.txt file for configuring the ZipLib target, you should not need to add the ZipFile.cpp file again. If this file is already compiled in the sub-directory into the target ZipLib, you do not need to compile it again into TryZip.
add_subdirectory(ExternalLibrary/ZipLib)
set(CMAKE_CXX_STANDARD 17)
add_executable(TryZip main.cpp)
target_include_directories(TryZip PRIVATE ExternalLibrary/ZipLib)
target_link_libraries(TryZip PRIVATE ZipLib)
EDIT: Based on your feedback, it appears ZipLib also depends on pthread but somehow it is not getting linked correctly. You might try to add the following to your ExternalLibrary/ZipLib/CMakeLists.txt file (if it doesn't already exist), to utilize CMake's FindThreads module:
find_package(Threads REQUIRED)
...
target_link_libraries(ZipLib PUBLIC Threads::Threads)

CMake, shared library linking fail

I'm currently getting used to cmake and I'm trying to compile a small project with a .so library linking.
My project is the following.
/
CMakeLists.txt
inc/
Als.h
src/
main.c
CMakeLists.txt
lib/
libals.so
build/
I'm compiling from the build directory with:
$ cmake ..
-- DIR:
-- Configuring done
-- Generating done
-- Build files have been written to: /home/julien/tmp/cmakeTest/build
And then:
$ make
Linking C executable cmakeTest
/usr/bin/ld: ne peut trouver -lals
collect2: error: ld returned 1 exit status
src/CMakeFiles/cmakeTest.dir/build.make:85: recipe for target 'src/cmakeTest' failed
make[2]: *** [src/cmakeTest] Error 1
CMakeFiles/Makefile2:75: recipe for target 'src/CMakeFiles/cmakeTest.dir/all' failed
make[1]: *** [src/CMakeFiles/cmakeTest.dir/all] Error 2
Makefile:76: recipe for target 'all' failed
make: *** [all] Error 2
The linker seems to be unable to find the libals.so file.
Here is the file /CMakeLists.txt:
cmake_minimum_required(VERSION 2.8)
PROJECT(cmaketest)
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall")
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Werror")
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O3")
INCLUDE_DIRECTORIES(
inc
)
ADD_SUBDIRECTORY(src)
get_directory_property(OUT_VAR LINK_DIRECTORIES)
message(STATUS "DIR: ${OUT_VAR}")
And here is the file /src/CMakeLists.txt:
PROJECT(cmakeTest)
FILE(
GLOB
${PROJECT_NAME}_Sources
*.c
)
INCLUDE_DIRECTORIES(
inc
inc
)
ADD_EXECUTABLE(
${PROJECT_NAME}
${${PROJECT_NAME}_Sources}
)
LINK_DIRECTORIES(
/home/julien/tmp/cmakeTest/lib/
)
TARGET_LINK_LIBRARIES(
${PROJECT_NAME}
als
pthread
)
Maybe I missed something but if I change the /src/CMakeLists.txt to:
PROJECT(cmakeTest)
FILE(
GLOB
${PROJECT_NAME}_Sources
*.c
)
INCLUDE_DIRECTORIES(
inc
inc
)
ADD_EXECUTABLE(
${PROJECT_NAME}
${${PROJECT_NAME}_Sources}
)
TARGET_LINK_LIBRARIES(
${PROJECT_NAME}
/home/julien/tmp/cmakeTest/lib/libals.so
pthread
)
The compilation is ok. Does someone know why the linker is unable to find libals.so when I'm giving him the good directory path to look in?
The LINK_DIRECTORIES functions seems not to be working.
Besides the solution you already have, and my solution in a comment, the problem you have with the CMake file shown is the order in which you invoke the CMake commands.
From the link_directories command reference:
The command will apply only to targets created after it is called.
[Emphasis mine]
You simply need to call link_directories before you call add_executable.

CMake: How to add dependency on linker script for executable

I have a CMake script where the final executable is linked with my own linker script:
cmake_minimum_required(VERSION 3.1)
project(test_app)
set(LINKER_SCRIPT "linker.ld")
set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -T ${LINKER_SCRIPT}")
add_executable(${PROJECT_NAME}.elf
main.cpp
startup.cpp
)
How do I make an executable dependent also on the linker script file (trigger linking if linker.ld was changed)?
You can add a LINK_DEPENDS property to your executable target, using set_target_properties. Add the following line after your add_executable command:
set_target_properties(${TARGET_NAME} PROPERTIES LINK_DEPENDS ${LINKER_SCRIPT})
The first argument to set_target_properties is the target name, i.e. the first argument you passed to add_executable.
I found this mail which described three possible ways for forcing an executable to be dependent on a linker script. Its author prefers this way:
CMakeLists.txt:
CMAKE_MINIMUM_REQUIRED(VERSION 2.8 FATAL_ERROR)
PROJECT(LINKERSCRIPT C)
FILE(WRITE main.c "void main(){}")
# dummy.c must exist:
ADD_EXECUTABLE(EXE main.c dummy.c)
# linkerscript must exist:
SET_SOURCE_FILES_PROPERTIES(
dummy.c PROPERTIES OBJECT_DEPENDS ${CMAKE_SOURCE_DIR}/linkerscript
)
Here dummy.c is an empty file, which is listed for the add_executable() command only for make resulted executable dependent on the linker script via the OBJECT_DEPENDS property.