Question

I would like to check specific compiler settings during compilation. I’m talking about settings set in xCode and used by the compiler.

for example, i would like to check this setting and conditionally compile code

#if GCC_OPTIMIZATION_LEVEL == 0
    NSLog(@"No Optimization");
#else
    NSLog(@"Optimization enabled");
#endif

The above code does not work, does anyone know how to do this ?

Answer 1

There is:

#define __OPTIMIZE__ 1

Which appears to be set whenever -O is set with a level above 0. If -O0 is used then this constant is not set.

This was found using:

$ gcc -O2 -dM -E - < /dev/null | grep -i opt

and:

$ gcc -O0 -dM -E - < /dev/null | grep -i opt

under Linux.