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From: "Randy Brukardt" <randy@rrsoftware.com>
Newsgroups: comp.lang.ada
Subject: Re: community-based compiler (was Re: What exactly is the licensing
 situation with GNAT?)
Date: Mon, 17 Nov 2014 18:52:23 -0600
Organization: Jacob Sparre Andersen Research & Innovation
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Xref: news.eternal-september.org comp.lang.ada:23494
Date: 2014-11-17T18:52:23-06:00
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"Luke A. Guest" <laguest@archeia.com> wrote in message 
news:464563264437706207.500344laguest-archeia.com@nntp.aioe.org...
> Shark8 <OneWingedShark@gmail.com> wrote:
>> On 14-Nov-14 14:07, Luke A. Guest wrote:
>>> Jesus! That would be hell. A compiler without dynamic memory? Really? No
>>> thanks.
>>
>> Ah, right; I'd forgotten about that restriction -- I was thinking more
>> along the lines of the prover-/verifier-tools -- though aren't there
>> large chunks where you don't need dynamic memory?
>
> Not really no. An entire compiler pretty much uses the heap exclusively,
> you'd be hard pressed to build a compiler using ore allocated memory or
> just static amounts in general.

That's not really true with Janus/Ada, as many things (types, compilation 
units, subprograms) are stored in static tables. That's a left-over from the 
early MS-DOS days, where those tables could be paged to disk or stored in 
"extended" memory rather than taking up limited main memory space. I've been 
slowly removing the paging code (it's just a complication that introduces 
bugs), but the static tables remain for the most part. (Some have become 
expandable by allocating them en-mass from the heap.)

There's still some major heap use for managing expression trees and the 
symbol table, but there's a lot that doesn't use it.

                                                 Randy.