Re: [Gcl-devel] Re: [Axiom-developer] New design for Axiom web site

[root]

Ok, I'm a little confused again. Must be my day for it. Lets see if I
can explain my confusion and then someone can clear it up for me.

It appears that there is a goal to have an "external build" of gcl.
The motivation seems to be that if someone already has gcl installed
then they could use the already installed gcl rather than build a new one.

I don't understand why this is important. After all the point of the gcl
build isn't to have an installed lisp but to build an axiom image. When
the axiom build finishes the lisp image is erased. Axiom will build on
many common lisps.

Axiom uses some functions which are not standard common lisp. The socket
code is custom code for Axiom. Every lisp we use will have to include that
socket code. The code isn't useful to anyone else so it should not be part
of any standard lisp distribution.

Axiom has to know details of each common lisp it is built upon. It is 
important that we study each lisp in detail in order to optimize axiom
for the best performance. This means that makefiles are going to be
sensitive to lisp we build. For instance, in the GCL build we explicitly
set memory parameters to avoid consing. CMUCL, CLISP, Franz, etc are going
to have different issues.

The current design uses a "standard distribution" unpacked from tar.gz
files that are easily replaced and are exact copies distributed by the
external projects. The tar.gz files allow us to ensure that we have a
"verified version" of each lisp. If we use an installed lisp we won't
have any way to guarantee which version of lisp we used. The user could
have strange intermediate versions and the "version number" doesn't 
capture all the necessary information.

I don't understand why it is important to use an already installed
lisp image.  It seems likely to be yet-another-source-of-trouble
like the X library issues. What am I missing?

Tim