Mixing C and C++ with CMAKE

Question

We write an application mainly in C but some sub-modules are written in C++ (on Linux). The problem is how to write CMakeLists.txt files to use g++ for some subdirectories and gcc for another.

Answer 1

The compiler and linker is usually determined by the file extension if not set otherwise. So as long as the file endings are fine, your code is compiled and linked with the correct compiler.

On a side note, remember to make the correct extern C declarations, if you mix C and C++.

Answer 2

CMake does this automatically. You can freely intermix both types of files in your CMakeLists.txt file:

. . .
add_executable(
    my_program
    code.cpp
    more_code.c
)

I do this all the time and it just works.

Answer 3

You can set LANGUAGE property of your source files to "CXX". See documentation.