error: invalid conversion from ‘const char*’ to ‘int’ [-fpermissive]

[JasperTan97]

I get the following error when catkin building. Does anyone know the fix?

error: invalid conversion from ‘const char*’ to ‘int’ [-fpermissive] omp_set_num_threads(MP_PROC_NUM);

[XW-HKU]

1. Varify if the openmp is installed, if not, apt install it:

sudo apt-get install libomp-dev

2. try catkin_make, not catkin build

[JasperTan97]

Hi @XW-HKU Thank you for your reply. I have installed openmp and done catkin_make. However I still get the error:

home/isera2/catkin_ws/src/FAST_LIO/src/laserMapping.cpp: In function ‘void h_share_model(state_ikfom&, esekfom::dyn_share_datastruct<double>&)’:
/home/isera2/catkin_ws/src/FAST_LIO/src/laserMapping.cpp:559:40: error: invalid conversion from ‘const char*’ to ‘int’ [-fpermissive]
         omp_set_num_threads(MP_PROC_NUM);
                                        ^
In file included from /home/isera2/catkin_ws/src/FAST_LIO/src/laserMapping.cpp:35:0:
/usr/lib/gcc/x86_64-linux-gnu/7/include/omp.h:86:13: note:   initializing argument 1 of ‘void omp_set_num_threads(int)’
 extern void omp_set_num_threads (int) __GOMP_NOTHROW;

[XW-HKU]

What's your ubuntu and gcc version? gcc --version

[JasperTan97]

gcc (Ubuntu 7.5.0-3ubuntu1~18.04) 7.5.0

I use ROS melodic, Eigen version 3.3.4.

I can run Fast_lio 1 but I cannot catkin_make this new version.

[XW-HKU]

A bit confusing, do you run git submodule update --init?

[XW-HKU]

may be you can try delete the devel/ and build/ directory before catkin_make

[JasperTan97]

A bit confusing, do you run git submodule update --init?

Yes I did. I have the ikd-tree files.

may be you can try delete the devel/ and build/ directory before catkin_make

I have cleaned and remade the folder many times.

I can't find where MP_PROC_NUM is defined in laserMapping.cpp In omp.h, the function takes in an int datatype, which I think is the source of the error. How was MP_PROC_NUM defined?

Once again, I like to thank you for your prompt responses!

[XW-HKU]

A bit confusing, do you run git submodule update --init?

Yes I did. I have the ikd-tree files.

may be you can try delete the devel/ and build/ directory before catkin_make

I have cleaned and remade the folder many times.

I can't find where MP_PROC_NUM is defined in laserMapping.cpp In omp.h, the function takes in an int datatype, which I think is the source of the error. How was MP_PROC_NUM defined?

Once again, I like to thank you for your prompt responses!

The MP_PROC_NUM is defined in CMakeLists.txt. It is predefined during cmake based on your cpu archtectuer.

Oh, what's your cpu type?

[JasperTan97]

cat /proc/cpuinfo | grep 'name'| uniq model name : Intel(R) Core(TM) i7-6600U CPU @ 2.60GHz cat /proc/cpuinfo | grep process| wc -l 4 (4 processors)

[XW-HKU]

When you fresh making the project, you will see the messages in terminator like below:

-- The C compiler identification is GNU 7.5.0 -- The CXX compiler identification is GNU 7.5.0 -- Check for working C compiler: /usr/bin/cc -- Check for working C compiler: /usr/bin/cc -- works -- Detecting C compiler ABI info -- Detecting C compiler ABI info - done -- Detecting C compile features -- Detecting C compile features - done -- Check for working CXX compiler: /usr/bin/c++ -- Check for working CXX compiler: /usr/bin/c++ -- works -- Detecting CXX compiler ABI info -- Detecting CXX compiler ABI info - done -- Detecting CXX compile features -- Detecting CXX compile features - done -- Using CATKIN_DEVEL_PREFIX: /home/xw/XW/ws_fastlio_hku/devel -- Using CMAKE_PREFIX_PATH: /home/xw/XW/ws_fastlio_hku/devel;/home/xw/ws_common/devel;/home/xw/ws_livoxrosdriver/devel;/opt/ros/melodic -- This workspace overlays: /home/xw/XW/ws_fastlio_hku/devel;/home/xw/ws_common/devel;/home/xw/ws_livoxrosdriver/devel;/opt/ros/melodic -- Found PythonInterp: /usr/bin/python2 (found suitable version "2.7.17", minimum required is "2") -- Using PYTHON_EXECUTABLE: /usr/bin/python2 -- Using Debian Python package layout -- Using empy: /usr/bin/empy -- Using CATKIN_ENABLE_TESTING: ON -- Call enable_testing() -- Using CATKIN_TEST_RESULTS_DIR: /home/xw/XW/ws_fastlio_hku/build/test_results -- Found gtest sources under '/usr/src/googletest': gtests will be built -- Found gmock sources under '/usr/src/googletest': gmock will be built -- Found PythonInterp: /usr/bin/python2 (found version "2.7.17") -- Looking for pthread.h -- Looking for pthread.h - found -- Looking for pthread_create -- Looking for pthread_create - not found -- Looking for pthread_create in pthreads -- Looking for pthread_create in pthreads - not found -- Looking for pthread_create in pthread -- Looking for pthread_create in pthread - found -- Found Threads: TRUE
-- Using Python nosetests: /usr/bin/nosetests-2.7 -- catkin 0.7.29 -- BUILD_SHARED_LIBS is on -- BUILD_SHARED_LIBS is on -- ~~~~~~~~~~~~~ -- ~~ traversing 1 packages in topological order: -- ~~ - fast_lio -- ~~~~~~~~~~~~~ -- +++ processing catkin package: 'fast_lio' -- ==> add_subdirectory(FAST_LIO) Current CPU archtecture: x86_64 Processer number: 16 core for MP: 3

You can show me the last three lines to see if there is any difference.

Current CPU archtecture: x86_64 Processer number: 16 core for MP: 3

[JasperTan97]

Current CPU archtecture: x86_64 Processer number: 4 core for MP: 2

[XW-HKU]

Current CPU archtecture: x86_64 Processer number: 4 core for MP: 2

That should be fine. what's your cmake version?

[JasperTan97]

cmake version 3.10.2

[XW-HKU]

cmake version 3.10.2

Seems everything is right.

[JasperTan97]

Hi, I made it work.

I replaced add_definitions(-DMP_PROC_NUM="${PROC_NUM}") in the CMakeLists.txt with add_definitions(-DMP_PROC_NUM=2) directly and it works fine. I'm not really sure what's the issue? Maybe the syntax is wrong or there is a bug with the typecasting but it now works.

Thanks so much for your time. We can close the issue if there's nothing else to add.

[XW-HKU]

MP_PROC_NUM

Thank you, there is truly a bug in cmake file, I fixed it in the newly update.