0e13b7e8dd
* HACKING: Update wrt syntax-case. * NEWS: Likewise. * README: Likewise. * guix.scm: Likewise.
106 lines
4.6 KiB
Org Mode
106 lines
4.6 KiB
Org Mode
-*-mode:org-*-
|
|
|
|
* Fully source-based bootstrapping
|
|
|
|
** R6RS-like scheme interpreter
|
|
This first part is prototyped in C by the mes.c core and Scheme
|
|
bootstrap code in module/. Of course, while mes.c is pretty small it
|
|
cannot serve as a fully source-based solution.
|
|
|
|
The initial idea was to have the minimal core support LISP-1.5 (or
|
|
something very close to that as a tribute to John McCarthy) and extend
|
|
eval/apply from LISP-1.5 source with define, define-macro etc. and
|
|
metamorphose into R6RS. It seemed to work but performance of the
|
|
LISP-intepreted RRS was so bad (~1000x slower than initial LISP-1.5)
|
|
that this track was abandoned after the initial ANNOUNCE.
|
|
|
|
The route changed, trying to strike a balance between core size and
|
|
performance: still writing as much as possible in Scheme but having a
|
|
mescc compiler that takes not more than some seconds to run.
|
|
|
|
Now that portable R6RS syntax-case runs and mes.c has grown to
|
|
~1200LOC with another ~300LOC of optional C code, some effort must
|
|
probably be directed into making that smaller.
|
|
|
|
** Move mes.c into hex?
|
|
One idea is to use OrianJ's amazing self-hosting [[https://github.com/oriansj/stage0][stage0]] hex assembler
|
|
and minimal bootstrap binaries and rewrite the mes.c core to directly
|
|
bootstrap into Scheme.
|
|
|
|
** Rewrite mes.c and generate hex?
|
|
Another idea (thanks Rutger!) is to rewrite the mes.c core in a
|
|
C/Assembly variant and thave mescc produce the simple, annotated
|
|
bootstrap binary.
|
|
|
|
* Bugs
|
|
** Core is too fat
|
|
mes.c is ~1500 lines (~10,000LOC Assembly) which seems much too big to
|
|
start translating it to assembly/hex.
|
|
|
|
** (mes-use-module ...) is a fake, see module/mes/base.mes.
|
|
All top level scripts and test files (scripts/*.mes tests/*.test)
|
|
now include appropriate (mes-use-module ...) stanzas.
|
|
|
|
This hack allows for scripts/includes.mes to generate the list of
|
|
files to be prepended. Previously, this information was put in
|
|
GNUmakefile.
|
|
** Garbage collection?
|
|
Mes is using malloc without freeing anything, memory is patient these
|
|
days :-) Sadly, a factor 10^6 less patient than the future that SICP
|
|
authors were hoping for (we have 10^3 less memory and 10^3 more
|
|
instructions).
|
|
|
|
SICP's stop and copy Garbage Colletor (Jam Scraper?) algorithm is now
|
|
available, but it cannot be hooked up yet as even in boot mode the
|
|
core mes eval/apply is still running; it executes the Scheme based
|
|
eval/apply.
|
|
** Actually do something useful, build: [[https://en.wikipedia.org/wiki/Tiny_C_Compiler][Tiny C Compiler]]
|
|
* OLD: Booting from LISP-1.5 into Mes
|
|
|
|
Mes started out experimenting with booting from a hex-coded minimal
|
|
LISP-1.5 (prototype in mes.c), into an almost-RRS Scheme.
|
|
|
|
When EOF is read, the LISP-1.5 machine calls loop2 from loop2.mes,
|
|
which reads the rest of stdin and takes over control. The functions
|
|
readenv, eval and apply-env in mes.mes introduced define, define-macro
|
|
quasiquote and macro expansion.
|
|
|
|
While this works, it's amazingly slow. We implemented a full reader
|
|
in mes.c, which makes running mes:apply-env mes:eval somewhat
|
|
bearable, still over 1000x slower than running mes.c.
|
|
|
|
Bootstrapping has been removed and mes.c implements enough of RRS to
|
|
run a macro-based define-syntax and syntax-rules.
|
|
|
|
loop.mes and mes.mes are unused and lagging behind. Probably it's not
|
|
worth considering this route without a VM. GNU Epsilon is taking the
|
|
more usual VM-route to provide multiple personas. While that sounds
|
|
neat, Lisp/Scheme, bootstrapping and trusted binaries are probably not
|
|
in scope as there is no mention of such things; only ML is mentioned
|
|
while Guile is used for bootstrapping.
|
|
|
|
* Assorted ideas and info
|
|
** C parser/compiler
|
|
*** [[https://savannah.gnu.org/projects/nyacc][nyacc]]
|
|
*** PEG: [[http://piumarta.com/software/peg/][parse C using PEG]]
|
|
*** [[https://en.wikipedia.org/wiki/Tiny_C_Compiler][Tiny C Compiler]]
|
|
*** [[http://www.t3x.org/subc/index.html][Sub C]]
|
|
*** [[https://groups.google.com/forum/#!topic/comp.lang.lisp/VPuX0VsjTTE][C intepreter in LISP/Scheme/Python]]
|
|
|
|
** C assembler/linker
|
|
*** [[http://www.tldp.org/HOWTO/Assembly-HOWTO/linux.html][Assembly HOWTO]]
|
|
*** System call clue bat
|
|
Basically, you issue an int 0x80, with the __NR_syscallname number
|
|
(from asm/unistd.h) in eax, and parameters (up to six) in ebx, ecx,
|
|
edx, esi, edi, ebp respectively.
|
|
*** ELF
|
|
7f 45 4c 46
|
|
*** [[http://www.muppetlabs.com/~breadbox/software/tiny/][Small ELF programs]]
|
|
*** [[http://www.cirosantilli.com/elf-hello-world/][Elf hello world]]
|
|
|
|
** RNRS
|
|
*** [[http://www.scheme-reports.org/][Scheme Reports]]
|
|
*** [[ftp://publications.ai.mit.edu/ai-publications/pdf/AIM-349.pdf][Scheme - Report on Scheme]]
|
|
*** [[ftp://publications.ai.mit.edu/ai-publications/pdf/AIM-452.pdf][RRS - Revised Report on Scheme]]
|
|
|