How do I show the value of a #define at compile time in gcc

Question

So far I\'ve got as far as:

#define ADEFINE \"23\"
#pragma message (\"ADEFINE\" ADEFINE)

Which works, but what if ADEFINE isn\'t a string?

Answer 1

To display macros which aren't strings, stringify the macro:

#define STRINGIFY(s) XSTRINGIFY(s)
#define XSTRINGIFY(s) #s

#define ADEFINE 23
#pragma message ("ADEFINE=" STRINGIFY(ADEFINE))

If you have/want boost, you can use boost stringize to do it for you:

#include 
#define ADEFINE 23
#pragma message ("ADEFINE=" BOOST_PP_STRINGIZE(ADEFINE))