Dynamic code changes

[Brian Blietz]

I am trying to implement dynamic code changes in programs compiled with gcc.

I have used the CFG (Control Flow Graph) implementation in GCC 3.2 to
break the code into basic blocks.

In each block, I have inserted a unique ID for the block.  This unique
ID is used to identify the flow of the program.

The code looks something like this:

pushl  (Unique ID)
call    Some_func

Some_func will use the unique ID in an arbitrary manner, which is not 
important.

What I would like to do, is go through the program and recalculate these 
unique ID's for each of
the blocks EVERY time it is run.

I really don't know where to start.  ANY help would be much appreciated.

Brian