Re: Testing integers in a Makefile?

[Der Herr Hofrat]

> Hi all,
> 
> Sorry to post this but I've spent a long time looking for information to
> solve my problem and still haven't found anything...
> 
> What I'd like to do is add some definitions to my DEFS variable depending on
> the value of _HARDWARE_REVISION (which is an integer).
> 
> My Makefile looks like this:
> DEFS=-D_HARDWARE_REVISION=005 -D_...
> ...
> COMPILE=$(TOOLDIR)/arm-elf-gcc -c -O2 -mcpu=arm7tdmi $(DEFS) -o
> "$(OUTDIR)/$(*F).o" "$<" -Wall
> 
> I'd like to write something like:
> $(if ($(_HARDWARE_REVISION) > 005),DEFS+=-D_ADD_THIS,DEFS+=-D_ADD_THAT)
> but I cannot find the right syntax for doing this...
>
make only knows about character strings - so you must use some external 
program to do the comparison you could use shell - something like: 

_HARDWARE_REVISION=12
eval = $(shell if [ $(1) -gt $(2) ] ; then echo gt ; else echo lt ; fi)


ifeq ($(call eval,$(VER),5),gt)
   DEFS+=-D_ADD_THIS
else
   DEFS+=-D_ADD_THAT
endif

show:
        @echo $(DEFS)