Re: Crosspost: Help wanted from comp.compilers

[Hyman Rosen <hyrosen@mail.com>]

Robert I. Eachus wrote:
> Now go back to 10.1.4(5), when you compile a compilation unit, "all 
> compilation units on which it depends semantically shall already exist 
> in the environment." So if you (successfully) recompile a unit on which 
> another unit semantically depends, those two units are now mutually 
> illegal.  How do you fix that?  You recompile the dependent unit.  Got it?

No. First of all, "exist in the environment" is not a defined concept,
and doesn't even have to mean object files. For GNAT, existing in the
environment just means that it can get at the source code of with'ed
modules. Second, nothing in what you stated implies that recompiling a
module forces it to be inconsistent with other already compiled modules
which depend on it. Some systems do this, but that is an implementation
shortcut they have taken, not a requirement from the language.

> But why am I spending this effort responding to a troll?

I'm not sure why you consider this to be a troll. If nothing else, the
fact the recompilation issues were part of the design requirements of
Ada 95 should demonstrate that Ada had significant problems in this area,
even without pessimizing compilation systems.