How to link to the C math library with CMake?

Question

How do I add the math library to my CMake file? This post references adding a target link library, yet I am not too familiar with C. An Additional post - Could

Answer 1

For various targets it's a good idea to test if adding a library is needed or not and if so where it's located of how it's named. Here's one way to do it:

:
include(CheckLibraryExists)

CHECK_LIBRARY_EXISTS(m sin "" HAVE_LIB_M)                                                                                                
                                                                                                                                         
if (HAVE_LIB_M)                                                                                                                          
    set(EXTRA_LIBS ${EXTRA_LIBS} m)                                                                                                      
endif (HAVE_LIB_M)

:
//More tests & build-up of ${EXTRA_LIBS}
:

add_executable(ch4 ch4.c)
target_link_libraries(ch4 PUBLIC ${EXTRA_LIBS})

For targets where libm is part of libc, the above test should fail, i.e. ${EXTRA_LIBS} will miss it and target_link will not try to add.