Makefile and defines with a value.

Have you ever wanted to change some code without changing the code?  I did this in the Makefile.  I did this with a define from the compiler command line.  A subset of the Makefiles follows:

<makefile>
# this is the top of the Makefile. I put switches here.
# comment out PRODVER if you want the original
PRODVER := MODIFIED
#MODIFIED Threshold for lower bounds
MODIFIED_THRESHOLD :=30000

#...

CFLAGS = -Wall -mlong-calls -ffunction-sections
ifeq ($(PRODVER),MODIFIED)
 CFLAGS += -DMODIFIED=$(MODIFIED_THRESHOLD)
endif
CFLAGS += $(OPTIMIZATION) $(INCLUDES)

</makefile>

The Makefile makes the same thing as:
#define MODIFIED 30000
but it does it as -DMODIFIED=30000 when the line is passed to gcc.

I want to set the minimum value of bounds
The C code looks like this:
<main.c>
 /*This is the modification the code based on code from the makefile*/
 #ifdef MODIFIED   //this is defined in the Makefile
 if(bounds &lt; MODIFIED)  //for our current Makefile, this will become (bounds&lt;30000)
 {
    bounds=MODIFIED;  //this sets the minimum value to be whatever is in the makefile.
 }                    //this line turns into bounds=30000;
 #endif

</main.c>