Recompile files for different parameters

[Matthias Fechner]

Dear list,

I have a small question regarding Makefile.
I have the case to compile a source tree with different CFLAGS, like
CFLAGS+=-DHARDWARE_REV_1

If I compile the source now it is compiled for hardware revision 1. What 
has to be compiled is defined by #ifdef statements in the code itself.

If I want to compile now for revision 2 I set other CFLAGS like:
CFLAGS+=-DHARDWARE_REV_2

The problem is now that make does not recompile the files again, because 
the dependencies are not different but the flags are.

Is there a possibility to put the flags into the dependencies so that 
make consider them?
Or should be another solution used for this case?

Thanks a lot for tips.

Bye,
Matthias

--
"Programming today is a race between software engineers striving to 
build bigger and better idiot-proof programs, and the universe trying to 
produce bigger and better idiots. So far, the universe is winning." -- 
Rich Cook