Re: Implementing an Ada compiler and libraries.

[Stefan Bellon <sbellon@sbellon.de>]

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.

In fact, this is the idea of the "compilercache" project for C and C++:
It intercepts calls to gcc/g++, builds a hash value on the
concatenation of the command line (minus a few switches that do not
influence code generation) and the preprocessed source and then stores
the resulting object file in the cache with the name of the hash value.
If the same hash value is to be compiled again, it is fetched from the
cache and a lot of compilation time is saved.

-- 
Stefan Bellon