Top Forums Programming question on conditional compilation Post 302136404 by the_learner on Monday 17th of September 2007 02:53:26 PM
question on conditional compilation

Hey, can I #define something outside the source file ?

I have a C program which uses #ifdef..

Code:
#ifdef ABC
 ... do this..
#else
 ... that ...
#endif

The usual way that I know of defining ABC is in the source/header file

Code:
#define ABC

But is there any other way to do that ? Maybe as an option to pass to the compiler ?

The reason is, I just want to run one script/makefile which will compile both versions of the progra, with ABC defined and without ABC defined.. without having to make changes in the source code.
 
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