how do I print a #defined constant in GDB?

Question

As per subject.

I have some constants hash defined like so:

#define CONST 40

I've set a break point in my program. How do I print the value of that constant? (I know I can just look at the source code, but I want to be sure of it)

Answer 1

help macro

You must compile with the -g3 flag for it to work and start your program before the macros are loaded.

In your case:

info macro CONST

or

macro expand CONST

More info: http://sourceware.org/gdb/current/onlinedocs/gdb/Macros.html