Speeding up pkg_version and perhaps other port utilities

[Stephen Montgomery-Smith]

Stephen Montgomery-Smith wrote:

>> 2.  Profile bsd make and see if there are any bottlenecks.  I bet make 
>> was never designed for speed in these kinds of situations.  But this 
>> would be a long term project, albeit definitely worth doing.
> 
> It looks to me like the variables are stored as a linear list in the 
> "make" program.  Thus if you have something like 500 variables (e.g. try 
> a "make -d g1 -V XX | grep = | wc -l" in a port) it is going to take 
> quite some time to search through all the variables to find one.  This 
> is especially a problem for variable assignments using "?=" which first 
> has to search to see if the variable is already defined.  And there are 
> a lot of "?=" in bsd.port.mk, 298 of them.  I haven't done any profiling 
> yet, but I bet that this is what is taking up all the time.  Probably 
> the way to solve this is to rewrite src/usr.bin/make/var.c so that it 
> uses some more sophisticated way of storing the variables - maybe 
> Berkeley databases is the way to go.  I almost get the feeling that if 
> make were completely rewritten in perl that it would go faster!

Profiling indicated that the linear lists were not the bottleneck.  I 
get the feeling that make is about as fast as it can be.