SBCL Internals : index

SBCL Internals
The pages on this CLiki-driven site can be edited by anybody at any time. No warranty of any kind can therefore be made; any implied warranties of merchantability or fitness for a particular purpose are expressly disclaimed

[ Home ]

[ Recent Changes ]

[ About CLiki ]

[ Text Formatting ]

Welcome to the SBCL Internals CLiki site.

This site is intended to be a source of information for anyone curious about the guts of the system, place to note reverse-engineered bits and pieces, forum for technical discussion and educated guesses about this complex beast we love.
"Why doesn't SBCL do XYZ?" is out of scope unless it really is a technical question -- but "How to add XYZ to SBCL" isn't, unless it is really silly.

There's also a SBCL Internals Manual, which is supposed to contain more documentation than noodling, guessing, planning, and status updates. It's probably the best place to start looking for authoritative things.

Usage guidelines:

Create short pages for concepts, objects, etc. Link to or paste in sbcl-devel archive messages. Paste in text from the doc/cmucl/internals directory (don't link), because the probability is that it needs updating as often as not. Worry about the site structure later; the search engine appears to work reasonably well.
Don't worry too much about acronym expansion. Where SBCL has a commonly used acronym (e.g. VOP), call the main page VOP and if you feel diligent create a secondary page Virtual OPeration that just says "See VOP". People have more chance of finding things that way round. Who knows what TN stands for anyway?
Don't write great long screeds; they're hard to find and hard to edit (yes, HTML forms suck as an editing interface). Exploit the advantages of hypertext by creating new pages at any and every opportunity.
Try and get the capitalization right. Pages named after Lisp symbols should be UPPERCASE, C functions should be all_lowercase, concepts should probably be Initial Caps, but use your own judgement.
Presently you can't use the percentage sign (%) in page names, due to a cliki engine bug. Dan-B will let you know when this is fixed. The asterisk (*) seems to be causing some problems too...

Some starting points (do add more -- the internal linkage is a bit weak currently)

Papers of interest to SBCL hackers.
Basics, very quick overview on things that stand out in the SBCL sources
TODO
Compiler, Frontend, Backend
Runtime - related to the C code in src/runtime
Library? - general-purpose code in src/code/
Build system - how it works, what the shell scripts do
Developing sbcl - how to ensure that sf.net and the other developers are happy
Porting
Threading
SB-BSD-SOCKETS
Pathnames?
Primitive Type System?
IR1
IR2
VOPs
Architectures
- Alpha
- PPC
- SPARC
- x86
- MIPS?
- HPPA
Operating systems
- Darwin aka Mac OS X
- NetBSD
- Linux?
- Solaris?
- FreeBSD?
- Win32
Source Tree Structure
Package Structure
Peephole Optimizer

There quite a few links to exterior sites, mostly archived messages describing an important aspect of the system. I suggest we copy those messages inside this cliki so that a) they are not frozen in time and indeed updated with actual information b) they do not vanish when their sites vanish

On c.l.l and #lisp etc., I have often seen sbcl and/or cmucl hackers comment something along the lines of 'well, it would be nice to have foo, but nobody is working on it.' For an outsider, it is very hard to see how much work, including time to ramp up on the internals, some of these little projects may take (for example, various optimizations that are lacking). I think it would be useful to have a page or pages here that gives both a how-best-to-get-started overview, and a list of small to medium projects that might be appropriate. It seems to me that sbcl is much more approachable in this way than cmucl... anyone have the time and insight to start this?

That's a pretty open question. I'd suggest you look at http://sbcl.sourceforge.net/porting.html for estimates on some of the more commonly-asked requests, but also that you createa Wishlist (or something) page here to ask more specific questions. I can't remember half of what goes on on #lisp either -- Daniel Barlow

List of all pages, mostly for the benefit of unbelievers and search engines

CLiki pages can be edited by anyone at any time. Imagine a fearsomely comprehensive disclaimer of liability. Now fear, comprehensively