How to run multiple C codes on Clion? - c

Question

This is my first question, so I'll try to explain everything about my problem. So, I had downloaded Clion to code my first C programs for my university degree. So, when I create a simple Hello World on C, I can run normally, but if I create a new program or a new hello world, the program fails with the following error on Clion:
> ====================[ Build | MeusCodigosC_2_0 | Debug ]======================== "C:\Program Files\JetBrains\CLion
> 2020.2.1\bin\cmake\win\bin\cmake.exe" --build "C:\Users\salom\CLionProjects\MeusCodigosC 2.0\cmake-build-debug"
> --target MeusCodigosC_2_0 -- -j 12 Scanning dependencies of target MeusCodigosC_2_0 [ 33%] Building C object
> CMakeFiles/MeusCodigosC_2_0.dir/AtividadeProducaoLabU2.c.obj [ 66%]
> Building C object CMakeFiles/MeusCodigosC_2_0.dir/HelloWorld.c.obj
> [100%] Linking C executable MeusCodigosC_2_0.exe
> c:/mingw/bin/../lib/gcc/mingw32/9.2.0/../../../../mingw32/bin/ld.exe:
> CMakeFiles\MeusCodigosC_2_0.dir/objects.a(HelloWorld.c.obj): na
> função "main": C:/Users/salom/CLionProjects/MeusCodigosC
> 2.0/HelloWorld.c:7: múltiplas definições de "main"; CMakeFiles\MeusCodigosC_2_0.dir/objects.a(AtividadeProducaoLabU2.c.obj):C:/Users/salom/CLionProjects/MeusCodigosC
> 2.0/AtividadeProducaoLabU2.c:32: definido primeiro aqui collect2.exe: error: ld returned 1 exit status mingw32-make.exe[3]: ***
> [MeusCodigosC_2_0.exe] Error 1 mingw32-make.exe[2]: ***
> [CMakeFiles/MeusCodigosC_2_0.dir/all] Error 2 mingw32-make.exe[1]: ***
> [CMakeFiles/MeusCodigosC_2_0.dir/rule] Error 2 mingw32-make.exe: ***
> [MeusCodigosC_2_0] Error 2
> CMakeFiles\MeusCodigosC_2_0.dir\build.make:119: recipe for target
> 'MeusCodigosC_2_0.exe' failed CMakeFiles\Makefile2:94: recipe for
> target 'CMakeFiles/MeusCodigosC_2_0.dir/all' failed
> CMakeFiles\Makefile2:101: recipe for target
> 'CMakeFiles/MeusCodigosC_2_0.dir/rule' failed Makefile:137: recipe for
> target 'MeusCodigosC_2_0' failed
I checked my CMakeLists.txt which I read that it's the file that makes your codes run, and the new code was already added to the target, but I still can't run it. The only workaround I had found is to delete the old code that I'm not using, and leave it only the code I want to use in that specific moment, only then I can run my C codes on Clion. Anyone had already face an issue like this? Thank you!

Answer 1

The error message says (if I understand Portuguese correctly) that the compiled files have several main functions defined in them.
main() is the function that runs when your program is executed. Several functions with the same name mean that the compiler doesn't know which one you want to run.
If you are writing several different programs, just keep them in separate folders, or make sure your CMakeLists.txt includes only one of them.
UPD: It looks like CLion supports one project creating multiple executable files. See documentation.
In your case, CMakeFile.txt should probably contain two lines (file names might need to be corrected):
add_executable(hello_world HelloWorld.c)
add_executable(MeusCodigosC_2_0 AtividadeProducaoLabU2.c)
If HelloWorld and Lab2 should share some code, you may extract it to a separate file, e.g. common.c, then update the project to say
add_executable(hello_world HelloWorld.c common.c)
add_executable(MeusCodigosC_2_0 AtividadeProducaoLabU2.c common.c)

Answer 2

I had this problem in clion and i fixed that. I Just opened new project and ta damm it worked.
it seems so easy to fix but my first time to using this so it was hard little bit for me :)