# openMP support (Battle for wesnoth)



## DavidMarec (Jul 4, 2018)

As I said in a previous message, it sounds that the port games/wesnoth is broken
if the openMP option is set ( which is the default), while running* FreeBSD 11.2*_._


```
[1/2] Building CXX object CMakeFiles/cmTC_b6544.dir/testCXXCompiler.cxx.o
    FAILED: CMakeFiles/cmTC_b6544.dir/testCXXCompiler.cxx.o
    /usr/local/bin/g++6    -O2 -pipe -march=k8-sse3  -fstack-protector -Wl,-rpath=/usr/local/lib/gcc6 -fno-strict-aliasing -Wc++11-narrowing  -nostdinc++ -isystem /usr/include/c++/v1 -Wl,-rpath=/usr/local/lib/gcc6 -std=gnu++11 -o CMakeFiles/cmTC_b6544.dir/testCXXCompiler.cxx.o -c testCXXCompiler.cxx
    g++6: error: unrecognized command line option '-Wc++11-narrowing'; did you mean '-Wno-narrowing'?
    ninja: build stopped: subcommand failed.
```

I'm working on a porting an more recent version of the game and I'm facing the same issue.
I don't known where the "_c++11-narrowing_" flag came from, but in the fist place, I was wondering why the port was build by gcc6 instead of clang6?

Actually, this is required by the openMP entry in the Makefile:


```
OPENMP_USES=  compiler:gcc-c++11-lib
```

using openmp feature instead 
	
	



```
OPENMP_USES= compiler:openmp
```
  would end up into the same situation, as defined in compiler.mk.

Is there any plan to allow the build of openMP based softwares against devel/llvm60,
as this port sets  the openmp feature on by default  ?

by the fact, I am able to build the game with openmp support by adding the following lines
after the <bsd.port.mk> inclusion:


```
.if ${PORT_OPTIONS:MOPENMP}
BUILD_DEPENDS+= ${LOCALBASE}/bin/clang60:devel/llvm60
CPP=    ${LOCALBASE}/bin/clang-cpp60
CC= ${LOCALBASE}/bin/clang60
CXX=    ${LOCALBASE}/bin/clang++60
.endif
```


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## DavidMarec (Jul 5, 2018)

DavidMarec said:


> I don't known where the "_c++11-narrowing_" flag came from, but in the fist place, I was wondering why the port was build by gcc6 instead of clang6?



Ok, this flag was simply added in /etc/make.conf. Why and when ? I can't even remember.


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## shkhln (Jul 5, 2018)

Wesnoth requires OpenMP? That's quite bizarre in itself. Anyway, it looks like they removed that dependency recently.


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## DavidMarec (Jul 5, 2018)

This is  still an option on the last release branch.

- And it really speed up the game on my side -


But beyond Wesnoth issues, this an overall question about dealing ports with openMP support.


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