CMakeLists.txt

add_library(scsl eigensolvers.c)
set_target_properties (scsl PROPERTIES COMPILE_DEFINITIONS SCSL)
target_link_libraries(scsl multithreading ${LAPACK_LIBS})

add_library(pcsl eigensolvers.c)
set_target_properties (scsl PROPERTIES COMPILE_DEFINITIONS "PCSL=1")
target_link_libraries(pcsl multithreading ${LAPACK_LIBS})

add_library(scpl eigensolvers.c)
set_target_properties (scsl PROPERTIES COMPILE_DEFINITIONS SCPL=1)
target_link_libraries(scpl multithreading ${LAPACK_LIBS})

eigensolvers.c

#ifdef SCSL
    void scsl_bxinv(FileRepresenation* input, FileRepresentation* result)
#elifdef SCPL
    void scpl_bxinv(FileRepresenation* input, FileRepresentation* result)
#elifdef PCSL
    void pcsl_bxinv(FileRepresenation* input, FileRepresentation* result)
#endif
{
 //do stuff
}

make VERBOSE=1

[ 75%] Building C object CMakeFiles/pcsl.dir/eigensolvers.c.o
/usr/lib/ccache/cc  -DLAPACK_DISABLE_NAN_CHECK -g -Wall -fopenmp -O2 -D_GNU_SOURCE -I/home/niklas/hpmc-final/src/../mr3smp-version-1.2/INCLUDE -I/home/niklas/hpmc-final/src/../OpenBLAS -I/home/niklas/hpmc-final/src/../lapack-3.4.2/lapacke/include    -o CMakeFiles/pcsl.dir/eigensolvers.c.o   -c /home/niklas/hpmc-final/src/eigensolvers.c
/home/niklas/hpmc-final/src/eigensolvers.c:21:1: Fehler: expected identifier or »(« before »{« token
make[2]: *** [CMakeFiles/pcsl.dir/eigensolvers.c.o] Fehler 1
make[2]: Verlasse Verzeichnis '/home/niklas/hpmc-final/bin-codeblox'
make[1]: *** [CMakeFiles/pcsl.dir/all] Fehler 2
make[1]: Verlasse Verzeichnis '/home/niklas/hpmc-final/b