[CMake] option, configure_file and ON/OFF

[Anton Deguet]

Hello,

I am trying to use a UI option to set a value used in configure_file and ideally obtain a file that doesn't use ON/OFF.   Here is a CMake sample:
  option (MYLIB_HAS_WHATEVER "Use whatever library" OFF)

In my config.h.in I have:
  #define ON 1
  #define OFF 0
  #define MYLIB_HAS_WHATEVER ${MYLIB_HAS_WHATEVER}

Then in my code I can use:
  #if MYLIB_HAS_WHATEVER
  ....
  #endif

It worked so far but there is an issue if we end up using other libraries which also define ON and/or OFF.  There seems to be no way to tell CMake to use 1/0 instead of ON/OFF during the configure_file.  My solution has been to modify my CMake to do the following:
  option (MYLIB_HAS_WHATEVER "Use whatever library" OFF)
  if (MYLIB_HAS_WHATEVER)
    set(MYLIB_CONFIG_HAS_WHATEVER 1)
    ....
  else (MYLIB_HAS_WHATEVER)
    set(MYLIB_CONFIG_HAS_WHATEVER 0)
    ....
  endif (MYLIB_HAS_WHATEVER)

and in the config.h.in do:
  #define MYLIB_HAS_WHATEVER ${MYLIB_CONFIG_HAS_WHATEVER}

Is there a better way?

Anton

---
Anton Deguet, Research Engineer, ERC-CISST/LCSR, Johns Hopkins University
e-mail: anton.deguet at jhu.edu, iChat: anton.deguet at mac.com
phone: 410-790-0456
JHU, LCSR, Hackerman Hall 137b, 3400 North Charles Street, Baltimore, MD 21218, USA