Re: Faster compilation speed

[Mike Stump <mrs at apple dot com>]

On Tuesday, August 13, 2002, at 05:27 AM, Theodore Papadopoulo wrote:
> OK, since this is a brainstorming about speeding up gcc, and since
> silly ideas are at least discussed, let me try one.
>
> Why not make incremental compilation a standard for gcc...
We have discussed this a bit here, and the option we would like, is the 
ability to recreate a single function from a translation unit, given 
the function desired.  The idea is to be able to edit a .c/.cc/.m file, 
and change a single function in a simple way (no change of arguments 
for example) and then recompile the translation unit with -fonly=foo 
(Ijust made that name up, forgive me) and take the result and have our 
system suck that .o up and place it into a program being debugged so 
that one can continue the debugging session with the change (no restart 
necessary).

I think this would be fairly easy to do in the compiler, and not 
require too many changes, and I think it would help speed the edit 
debug compile cycle quite a bit.

I think this would be a bit less work that your suggestion, and our 
hope is that it would provide most of the benefit.

Yes, I'm aware that this doesn't play nicely with templates, inline 
function bodies, changes to headers and the like.

Would enough other people find this useful enough to make the changes 
to the compiler acceptable in general?
We could try the simpler form for a while, and see if that satisfies 
the need enough to not do the `full' job.  Of course, we always have 
the freedom to do the full thing, if people find it compelling enough.

Thoughts?  What should the name of the option be?  Maybe we should 
start out with a possible list instead of a single function?