I am compiling my code, in which I use posix threads in C.
I am using CLion and its CMakeLists.txt:
cmake_minimum_required(VERSION 3.7)
project(Test)
set(CMAKE_C_STANDARD 99)
add_definitions(-lpthread)
set(SOURCE_FILES main.c)
add_executable(Test ${SOURCE_FILES})
I am getting errors (eg: undefined reference tosem_init'`).
The proposed suggestion for solution is adding -lpthread compiler flag, but I already added it.
I compiled the same code from commandline:
gcc main.c -lpthread
It compiles without any problem.
What can be a possible problem/solution for this?
Remove add_definitions(-lpthread) entirely since pthread is not a definition, but a library dependency.
Add after add_executable():
target_link_libraries(Test pthread)
Also, if you want to see what commands CMake is using without having to examine its files, you can use it on the command line with cmake -DCMAKE_VERBOSE_MAKEFILE=ON ....
Btw, always prefer all the target_* commands, like target_compile_definitions() instead of older style add_definitions(). This keeps your project properties and dependencies clean and minimizes interference between different targets.
If after the above changes your code still does not compile, then it is highly likely the code itself is wrong (nothing to do with CMake).
Related
I'm trying to compile a project in C++ using cmake, and in the page of the project they tell me that it will crash if I don't add the standard 98. (I'm on a mac)
I've tried all I found on the internet and I could manage to make the cmake use the option -std=c++98 but it also adds -DNDEBUG -std=gnu++11. (I saw it using the make VERBOSE=1 option)
I would like to get rid of that. Using the --trace option I could see that the option is set in a file which is in the cellar folder, that is, is something that has to do with cmake itself and not in the CMakeList.txt file im using.
How can I solve this problem?
If it can help the code I'm trying to compile is this:
SAMoS
Thank you.
UPDATE:
with the --trace option I was able to see that the -std=gnu++11 option was selected in the file:
/usr/local/Cellar/cmake/3.9.4.1/share/cmake/Modules/Compiler/GNU-CXX.cmake
which can be seen here GNU-CXX.cmake
If I eddit that file in a way that every if sets the option to -std=c++98 then, the cmake complains giving me the next error:
CMake Error in src/CMakeLists.txt:
The compiler feature "cxx_nullptr" is not known to CXX compiler
"GNU"
version 7.2.0.
I don't know what else can I try...
You need to set the language standard:
set(CMAKE_CXX_STANDARD 98)
Depending on the compiler, it may enable extensions as well. To disable the GNU extensions also add:
set(CMAKE_CXX_EXTENSIONS OFF)
Note that setting this options does so only for the specified target and dependent targets.
Have take a look at this section of the CMake manual for more information on compiler features. Do note however, using this
The inclusion of VTK is polluting SAMoS's CMake scope with the C++11 requirement. You can test this by disabling VTK on your cmake command line.
$ cd ~SAMoS
$ mkdir build; cd build
$ cmake -DVTK_FOUND=FALSE ../
[...]
$ make VERBOSE=1
[...]
Scanning dependencies of target samos
/Applications/Xcode.app/Contents/Developer/usr/bin/make -f src/CMakeFiles/samos.dir/build.make src/CMakeFiles/samos.dir/build
[ 1%] Building CXX object src/CMakeFiles/samos.dir/samos.cpp.o
cd /Users/nega/SAMoS/build/src && /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++ -DCGAL_USE_GMP -DCGAL_USE_MPFR -DHAS_CGAL -isystem /usr/local/include -I/include -I/Users/nega/SAMoS/src/constraints -I/Users/nega/SAMoS/src/dump -I/Users/nega/SAMoS/src/log -I/Users/nega/SAMoS/src/integrators -I/Users/nega/SAMoS/src/messenger -I/Users/nega/SAMoS/src/parser -I/Users/nega/SAMoS/src/potentials -I/Users/nega/SAMoS/src/potentials/external -I/Users/nega/SAMoS/src/potentials/pair -I/Users/nega/SAMoS/src/potentials/bond -I/Users/nega/SAMoS/src/potentials/angle -I/Users/nega/SAMoS/src/system -I/Users/nega/SAMoS/src/utils -I/Users/nega/SAMoS/src/aligner -I/Users/nega/SAMoS/src/aligner/pair -I/Users/nega/SAMoS/src/aligner/external -I/Users/nega/SAMoS/src/population -I/Users/nega/SAMoS/src -I/Users/nega/SAMoS/build -DNDEBUG -o CMakeFiles/samos.dir/samos.cpp.o -c /Users/nega/SAMoS/src/samos.cpp
You'll notice there's no -std=gnu++11 flag anymore. Of course, since it looks like you're GCC version 7.2, you'll still want your set CMAKE_CXX_STANDARD to 98 since gcc-7.2 uses C++11 by default. (Or maybe it's C++14 now...) You can do this on your cmake command line.
$ cmake -DUSE_VTK=FALSE -DCMAKE_CXX_STANDARD=98 ..
CMake will then add -std=gnu++98 to its compile commands.
If you can't live without VTK, then you'll need to send a bug report upstream asking the SAMoS folks to clarify their documentation, or fix how they're including VTK.
I am a novice to cmake and boost so this question might be missing something obvious:
I am building a project with cmake on linux (ubuntu) and I am trying to use boost logging in that project. Here is what I do to generate the Makefile:
rm CMakeCache.txt
cmake ../ -DCMAKE_EXE_LINKER_FLAGS="-lboost_log -lboost_log_setup -lpthread -std=c++11" -DCMAKE_SHARED_LINKER_FLAGS="-lboost_log_setup -lboost_log -lpthread" -DCMAKE_MODULE_LINKER_FLAGS="-lboost_log_setup -lboost_log -lpthread" -DCMAKE_CXX_FLAGS="-DBOOST_LOG_DYN_LINK -std=c++11"
Compile goes through fine. (Some of these flags may be overkill -- I should only need the CMAKE_EXE_LINKER_FLAGS).
When I run the executable, I get the following unresolved reference:
-- ImportError: /home/mranga/gr-msod-sensor/gr-msod_sensor/build/lib/libgnuradio-msod_sensor.so: undefined symbol: _ZN5boost3log11v2_mt_posix3aux25unhandled_exception_countEv
What flags am I missing? My boost library is set up and LD_LIBRARY_PATH points to the right location.
When I manually built a test program using the same linker flags, it compiles and runs fine so boost is installed correctly. I hope I have not missed the obvious.
(Moved question from the GNU Radio mailing list -- sorry if you are reading this post for a second time).
I believe the order of libraries in the linker command line in -DCMAKE_EXE_LINKER_FLAGS is incorrect. boost_log_setup depends on boost_log, so boost_log_setup should go first.
You seem to be linking against the non-multithreaded version:
-lboost_log
but the run-time linker seems to explicitely look for the multithreaded variant (the Boost doc site on that):
_ZN5boost3log11v2_mt_posix3aux25unhandled_exception_countEv
^^
My guess hence is that you should try linking with
-lboost_log_mt
but the question whether that is right or not depends too much on your individual project to make it possible for me to clearly answer this.
[Shamelessly cross-posted from the CMake help list]
I'm trying to create binaries as statically as possible. The fortran code I've got has got X11 and quadmath as dependencies, and I've come across a number of issues (maybe each of these issues should be in a different question?):
My variables are currently
set(CMAKE_LIBRARY_PATH /usr/X11/lib /usr/X11/include/X11 ${CMAKE_LIBRARY_PATH})
find_package(X11 REQUIRED)
find_library(X11 NAMES X11.a PATHS /usr/X11/include/X11/ /usr/X11/lib)
find_library(X11_Xaw_LIB NAMES Xaw Xaw /usr/X11/include/X11/ /usr/X11/lib ${X11_LIB_SEARCH_PATH})
find_library(Xaw Xaw7 PATHS ${X11_LIB_SEARCH_PATH})
set(CMAKE_LIBRARY_PATH /usr/lib/gcc/x86_64-linux-gnu/4.7 /usr/lib/gcc/x86_64-linux-gnu/4.7/x32 /usr/lib/gcc/x86_64-linux-gnu/4.7/32 ${CMAKE_LIBRARY_PATH})
find_library(quadmath NAMES quadmath.a)
set(BUILD_SHARED_LIBS ON)
set(CMAKE_FIND_LIBRARY_SUFFIXES .a ${CMAKE_FIND_LIBRARY_SUFFIXES})
set(LINK_SEARCH_START_STATIC TRUE)
set(LINK_SEARCH_END_STATIC TRUE)
set(SHARED_LIBS OFF)
set(STATIC_LIBS ON)
set(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE)
set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -static")
Using these, CMake attempts to build every program statically (as expected) - however, it fails because I don't have Xaw.a - I can't find out whether this actually should exist. I have installed the latest libxaw7-dev which I was expecting to fix it. One option would be to compile the X11 libraries myself, but I don't really want to do that...
if I comment out only set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -static"), then CMake compiles everything, but uses shared libraries for every program, even though I specify the location of .a X11 libraries in my find_library() calls. I was expecting CMake to use the .a files where it could and then only use shared libraries - is there a way to force this behaviour?
does anyone know yet of a fix for the bug described here: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46539; whereby gfortran seemingly can't statically link libquadmath? I tried the fix using gcc but I can't get CMake to recognise the libgfortran flag:
cmake -DCMAKE_Fortran_COMPILER=gcc -DCMAKE_Fortran_FLAGS=-gfortran
results in
-- The Fortran compiler identification is unknown
-- Check for working Fortran compiler: /usr/bin/gcc
-- Check for working Fortran compiler: /usr/bin/gcc -- broken
CMake Error at /usr/share/cmake-2.8/Modules/CMakeTestFortranCompiler.cmake:54 (message):
The Fortran compiler "/usr/bin/gcc" is not able to compile a simple test program.
However, as you might have noticed, I set the location of the libquadmath.a; when I build a program which doesn't use X11 but does use quadmath when I use
set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -static")
then the program does compile successfully (running ldd reports 'not a dynamic executable') - does this mean that the bug has been fixed, or does it only work because I set the location in CMake?
I was having a similar problem. Turns out that cmake was implicitly linking against libgfortran and libquadmath. To fix this I put the following in my top level CMakeLists.txt:
unset(CMAKE_Fortran_IMPLICIT_LINK_LIBRARIES)
I could then explicitly link again the libraries using:
SET_TARGET_PROPERTIES(main_f PROPERTIES LINKER_LANGUAGE "C"
LINK_FLAGS
"/usr/local/Cellar/gcc/7.1.0/lib/gcc/7/libgfortran.a
/usr/local/Cellar/gcc/7.1.0/lib/gcc/7/libquadmath.a -lm -lgcc"
)
The static version of libgfortran is necessary because the shared library also depends on libquadmath. The added "-lm" and "-lgcc" bring in the system dynamic versions of these libraries. On a mac system, you would want to use the full path to your libm.a as well.
I guess your questions are not that much related, I don't know the answer for all of them.
For your static linking problems, since you're using GCC, you can pass multiple -static and -dynamic flags to it:
set(CMAKE_EXE_LINKER_FLAGS "-static ${STATIC_LIBS} -dynamic ${EVERYTHING ELSE} -static ${MORE_STATIC_LIBS}")
I don't know why Xaw.a isn't available on your system, probably because the package maintainer of your Linux distribution didn't really make them available.
Also, compiling everything static might make things not compatible between all distros out there and you cripple the ability for others to use improved, up-to-date libraries with your program, it might not be what you want.
If you intend to make a self-contained package of your program, it might be better just to include the shared libraries you used together, like Dropbox and many other proprietary applications do (Humble Bundle games are other example).
I'm trying to use cmake (on Linux with GNU make and g++) to build a project with two sub-directories: MyLib and MyApp. MyLib contains source for a static library; MyApp needs to link against that library. I'm trying to build on Linux with generated makefiles using the following CMakeLists.txt:
cmake_minimum_required (VERSION 2.6)
project (MyProj)
include_directories (MyLib)
file(GLOB MyLibSrc MyLib/*.cpp)
add_library(MyLibrary STATIC ${MyLibSrc})
file(GLOB MyAppSrc MyApp/*.cpp)
add_executable(MyApplication ${MyAppSrc})
target_link_libraries(MyApplication MyLibrary)
This 'almost' works. It fails at link time because while it generates libMyLibrary.a - it is in the root. When I add:
link_directories(${MyProj_BINARY_DIR})
it makes no difference.
I've got a few (inter-linked) questions:
What's the best way to coerce cmake into building my library and executable into a 'staging directory' — say MyStage — to keep targets separate from source?
How do I convince cmake to link the application against the library?
If I wanted to build a debug and a release version, what's the best way to extend my cmake scripts to do this — making sure that the debug application links against the debug library and the release application against the release library?
I'm a relative newcomer to cmake. I've read what I can find on the web, but find myself struggling to get my library to link with my executable. This sort of a configuration, to my mind, should be quite common. An example from which to crib would be very helpful, but I've not found one.
Well, it is better to read this example and do exactly as suggested.
cmake_minimum_required (VERSION 2.6)
project (MyProj CXX)
add_subdirectory(MyLib)
add_subdirectory(MyApp)
Then for each subdirectory specified, CMakeLists.txt files are created
MyLib\CMakeLists.txt
file(GLOB SRC_FILES *.cpp)
add_library(MyLib ${SRC_FILES})
MyApp\CMakeLists.txt
file(GLOB SRC_FILES *.cpp)
add_executable(MyApp ${SRC_FILES})
target_link_libraries(MyApp MyLib)
Use "out of the source build". Make a directory used only for build and while in it, call
cmake <path to the sources, it may be relative>
Either use
link_directories(${MyProj_BINARY_DIR}/MyLib)
or make CMakeLists.txt in each subdirectory - that would be better for project larger than very small.
This is a bit tricky, check out CMAKE_BUILD_TYPE in the docs (you can set it and/or "if" by it). You can also set it from command line:
cmake -DCMAKE_BUILD_TYPE=Debug
I've discovered the 'optimal' solution to (1)... so, thought I should post it here:
SET(CMAKE_ARCHIVE_OUTPUT_DIRECTORY MyStage)
SET(CMAKE_RUNTIME_OUTPUT_DIRECTORY MyStage)
The thing that confused me previously is that static libraries are not considered a LIBRARY by Cmake - they're considered to be ARCHIVEs.
Do not add libraries and executables in the root Cmakelists.txt. Add these libraries and executables in Cmakelists.txt of subdirectories.
I'm a learning c++ developer writing a game initially on the Mac platform using XCode, but now moving to cross platform by leveraging CMake. So far I can get it compiled on my ickle linux netbook and I'm putting together a dev environment on this machine for on the go coding. However I'm finding that gcc recompiles every file whenever I make a change. Clearly I need some additional configuration to the CMakeLists.txt . My current one is very simple. Like so;
cmake_minimum_required (VERSION 2.8)
set (source
Creature.cpp
DisplayManager.cpp
Engine.cpp
EngineState.cpp
Entity.cpp
GameWorld.cpp
GfxSFML.cpp
Item.cpp
Map.cpp
Position.cpp
Projectile.cpp
ScreenTile.cpp
SquadAI.cpp
Terrain.cpp
UIButton.cpp
UICharPanel.cpp
UIView.cpp
Utility.cpp
Weapon.cpp
fov.cpp
main.cpp
)
find_package (OpenAL)
find_package (OpenGL)
find_package (SFML)
set(CMAKE_CXX_FLAGS "-g -Wall -pg")
add_executable (tractionedge ${source})
target_link_libraries(tractionedge ${SFML_LIBRARY} ${OPENGL_LIBRARY} ${OPENAL_LIBRARY})
I've concentrated so far on C++ as a language rather than build systems by sticking with XCode for everything. My knowledge of Autotools (make?) and Gcc is very limited. How do I have gcc only recompile the changed source?
Are you rerunning cmake every time? If you just modify one source file, you should be able to simply rerun make, and it should rebuild just the one object file before linking. If you rerun cmake, it might mark all of the source files dirty and rebuild everything.
Only rerun cmake if you change the actual list of source files being used, or other major changes like that.
Rebuilding only the modified sources SHOULD be the default behavior. Of course if you change a central header included by nearly all dependent cpp files it'll trigger a nearly complete rebuild. Look at what happens if you only modify one cpp file (adding a comment or alike), if more than that compilation unit is compiling then I propose you to invest more time investigating it eventually giving you my EMail to have a deeper look at the configuration.
Another possibility is that you are compiling under windows and using a 2.8 cmake that has a bug regarding this. Look at a 2.9 version to see if that defect is away then: http://www.mail-archive.com/cmake#cmake.org/msg24876.html
I would rewrite your CMakeLists.txt using glob (maybe move the files in a "src" directory if you have other *.cpp files around) and give your project a name (this sets some important variables):
cmake_minimum_required (VERSION 2.8)
project(TRACTION)
file (GLOB TRACTION_SOURCES *.cpp)
find_package (OpenAL)
find_package (OpenGL)
find_package (SFML)
set(CMAKE_CXX_FLAGS "-g -Wall -pg")
add_executable (tractionedge ${TRACTION_SOURCES})
target_link_libraries(tractionedge ${SFML_LIBRARY} ${OPENGL_LIBRARY} ${OPENAL_LIBRARY})
I also experienced unnecessary rebuilds using cmake and visual studio. The problem is related to an inappropriate x64 configuration parameter: Visual Studio 2008 Unnecessary Project Building
A simple solution in many of these cases is to completely wipe the build tree and regenerate it (and I mean something along the lines of rm -rf build && mkdir build && cd build && cmake -G "Unix Makefiles" ../src, not just make clean)