Hi Manal, > I am looking for an ANSI C preprocessor directive that can make code run only when I am in debugging mode (compiled with gcc -g option) gcc -g does not introduce a define, you have to do that yourself. As you can see from this diff: diff <(gcc -g -E -dM -x c++ - <<<'' | sort) <(gcc -E -dM -x c++ - <<<'' | sort) A rather widespread convention dating back to the misty dawn of time is that debug compiles *LACK* the NDEBUG preprocessor define (e.g., -UNDEBUG), and that release compiles declare the NDEBUG preprocessor define (e.g., -DNDEBUG). So to compile your debug code, do this: gcc -g And to compile your release code, do this: gcc -DNDEBUG > I found something like: #if DEBUG Do this in debug; #else do this optionally if not in debug #endif Change that to: #ifndef NDEBUG Do this in debug; #else do this optionally if not in debug #endif > but it didn't work, as DEBUG is not defined, Correct, since you did not define it. For your team, you can adopt any of these other fairly prevalent conventions: debug: gcc -g -DDEBUG debug: gcc -g -D_DEBUG release: gcc -DRELEASE release: gcc -D_RELEASE Note: _DEBUG is often seen in Microsoft C, C++, Visual C++ project debug builds, and NDEBUG in their release builds. I prefer to use the NDEBUG indicating release, and absence of NDEBUG indicating debug. debug: gcc -g -UNDEBUG release: gcc -DNDEBUG The <assert.h> or <cassert> headers are affected by the presence or absence of NDEBUG. HTH, --Eljay
