[CMake] FW: building a mixed language programm with CMake

[Denis Scherbakov]

> $ nm test.o
> U __gxx_personality_v0
> U hello1_
> 0000000000000000 T main
> $ nm hello.o
> U _gfortran_st_write
> U _gfortran_st_write_done
> U _gfortran_transfer_character
> 0000000000000000 T hello1_

So you're calling Fortran from C.

> /usr/bin/gfortran   -fPIC 
> CMakeFiles/hi.dir/hello.o  -o hi -rdynamic -lgfortran 

The problem is that CMake decides to use gfortran as a linker, not gcc,
because we specified that this is a Fortran project and forgot about C++.
So the solution is:

# To indicate that this is mixed language project
PROJECT(TEST CXX Fortran)
# To explicitly specify that your MAIN is C++'s main.
SET_TARGET_PROPERTIES(test PROPERTIES LINKER_LANGUAGE CXX)

"set_target_props" without "project" will not work.

Denis