Re: Implementing an Ada compiler and libraries.

[Stefan Bellon <sbellon@sbellon.de>]

Ludovic Brenta wrote:

> Stefan Bellon <sbellon@sbellon.de> writes:
> > Gautier wrote:
> >
> >> - time stamps to check need of recompilations
> >
> > I've always wondered about the focussing on time stamps. I think
> > the way to do it would be to calculate a hash sum (md5, sha1, ...)
> > on the token stream without comments. This way you wouldn't have to
> > recompile if you do layout and commentary changes, and even if you
> > touch the file, you don't inadvertently trigger a recompilation.
> 
> That's what GNAT does, only it uses a simple checksum for performance
> reasons.  Calculating the checksum and comparing it with the one in
> the library (.ali files in the case of GNAT) has to be faster than
> recompiling the file.

But timestamps are considered as well. If you touch a file without
modifying it otherwise, it triggers a recompilation.

-- 
Stefan Bellon