@@ -57,15 +57,54 @@ (define-module (gnu packages chez)
;; Commentary:
;;
;; The bootstrapping paths for Chez Scheme and Racket are closely
-;; entwined. Racket CS (the default Racket implementation) is based on (a fork
-;; of) Chez Scheme. Racket's variant of Chez Scheme shares sources for
-;; nanopass and stex with upstream Chez Scheme.
+;; entwined. See "Bootstrapping Racket" in the commentary on "racket.scm" for
+;; details on the Racket portion of Chez Scheme's bootstrapping path.
;;
-;; Racket's variant of Chez Scheme can be bootstrapped by an older Racket
-;; implementation, Racket BC, which can be bootstrapped from C. Porting that
-;; code to work with upstream Chez Scheme (or finding an old version that
-;; does) is our best hope for some day bootstrapping upstream Chez Scheme from
-;; source.
+;; Chez Scheme is a self-hosting compiler. A small kernel implemented in C
+;; loads "boot files" (in a custom object file format) compiled from the parts
+;; of the system implemented in Chez Scheme. (While Chez Scheme generates
+;; native machine code, it implements its own linker and loader.)
+;;
+;; As of Chez Scheme 10.0.0 (and the pre-release versions that preceded it on
+;; the Racket branch), there are several ways to obtain boot files:
+;;
+;; 1. The Racket package "cs-bootstrap" (in the "racket/src/rktboot/"
+;; directory of the main Racket Git repository) simulates enough of Chez
+;; Scheme to load the Chez Scheme compiler purely from source into Racket
+;; and apply the compiler to itself, producing the needed boot files
+;; (albeit very slowly).
+;; Any variant of Racket since version 7.1 can run the simulation. Using
+;; the older Racket BC implementation, which does not depend on Chez
+;; Scheme, breaks the dependency cycle.
+;; However, the simulation relies on implementation details of Chez
+;; Scheme, so a given version of Chez Scheme can only be bootstrapped by
+;; the corresponding version of the "cs-bootstrap" package.
+;;
+;; 2. The Chez Scheme makefile provides a "re.boot" target for bootstrapping
+;; via a different version of Chez Scheme (9.5.4 or later).
+;; This path manages potential differences in implementation details
+;; across Chez Scheme versions using a strategy similar to "cs-bootstrap",
+;; but the compatibility shim is maintained with the Chez Scheme source
+;; code (in "s/reboot.ss"). Also, it's faster, since less indirection is
+;; needed.
+;;
+;; 3. For cross-compilation, or with an extremely similar Chez Scheme, the
+;; makefile provides "cross.boot" and related targets.
+;;
+;; 4. The Chez Scheme Git repository includes pre-built "pb" (portable
+;; bytecode) boot files, which can be used for bootstrapping on any
+;; platform, but these binary files are removed from the source Guix uses.
+;;
+;; Concretely, we use racket-vm-bc to bootstrap chez-scheme-for-racket, which
+;; we then use to bootstrap both chez-scheme and racket-vm-cs.
+;;
+;; In principle, it would be possible instead to use chez-scheme to bootstrap
+;; chez-scheme-for-racket. However, since Racket is ultimately used for
+;; bootstrapping, chez-scheme would still need to be rebuilt when Racket
+;; changes, whereas treating chez-scheme as a leaf avoids having to rebuild
+;; Racket when upstream Chez Scheme changes. Furthermore, since "cs-bootstrap"
+;; is developed in the Racket source repository, we don't have to look for the
+;; version of "cs-bootstrap" compatible with the upstream Chez Scheme release.
;;
;; Code:
@@ -476,7 +515,8 @@ (define-public chez-scheme
(for-each (lambda (dir)
(when (directory-exists? dir)
(delete-file-recursively dir)))
- '("lz4"
+ '("boot"
+ "lz4"
"nanopass"
"stex"
"zlib"
@@ -572,10 +612,10 @@ (define-public chez-scheme-for-racket-bootstrap-bootfiles
"/opt/racket-vm/bin/racket")
"../rktboot/main.rkt"))))))))
(home-page "https://pkgs.racket-lang.org/package/cs-bootstrap")
- (synopsis "Chez Scheme bootfiles bootstrapped by Racket")
- (description "Chez Scheme is a self-hosting compiler: building it
-requires ``bootfiles'' containing the Scheme-implemented portions compiled for
-the current platform. (Chez can then cross-compile bootfiles for all other
+ (synopsis "Chez Scheme boot files bootstrapped by Racket")
+ (description "Chez Scheme is a self-hosting compiler: building it requires
+``boot files'' containing the Scheme-implemented portions compiled for the
+current platform. (Chez can then cross-compile boot files for all other
supported platforms.)
The Racket package @code{cs-bootstrap} (part of the main Racket Git
@@ -588,28 +628,57 @@ (define-public chez-scheme-for-racket-bootstrap-bootfiles
(define-public chez-scheme-bootstrap-bootfiles
(package
- (inherit chez-scheme)
(name "chez-scheme-bootstrap-bootfiles")
- (inputs '())
- (native-inputs '())
+ (version (package-version chez-scheme))
+ (source (package-source chez-scheme))
+ (native-inputs (list chez-nanopass-bootstrap
+ (if (%current-target-system)
+ chez-scheme
+ chez-scheme-for-racket)
+ zuo))
(outputs '("out"))
- (build-system copy-build-system)
- ;; TODO: cross compilation
+ (build-system gnu-build-system)
(arguments
- (list #:install-plan
- #~`(("boot/" "lib/chez-scheme-bootfiles"))))
- (synopsis "Chez Scheme bootfiles (binary seed)")
+ (list
+ #:configure-flags
+ #~`("--force" ; don't complain about missing bootfiles
+ "ZLIB=-lz" "LZ4=-llz4" "STEXLIB=/GuixNotUsingStex" ; ignore submods
+ "ZUO=zuo"
+ ;; could skip -m= for non-cross non-pbarch builds
+ #$(string-append "-m=" (or (nix-system->native-chez-machine-type)
+ (nix-system->pbarch-machine-type))))
+ #:make-flags
+ #~(list (string-append "SCHEME="
+ (search-input-file %build-inputs "/bin/scheme"))
+ #$(if (%current-target-system)
+ "cross.boot"
+ "re.boot"))
+ #:phases
+ #~(modify-phases %standard-phases
+ (add-after 'unpack 'unpack-nanopass
+ #$unpack-nanopass)
+ (replace 'configure
+ #$chez-configure)
+ (delete 'check)
+ (replace 'install
+ (lambda args
+ (mkdir-p (string-append #$output "/lib"))
+ (copy-recursively
+ "boot"
+ (string-append #$output "/lib/chez-scheme-bootfiles")))))))
+ (home-page "https://cisco.github.io/ChezScheme/")
+ (synopsis "Bootstrapped Chez Scheme boot files")
(description
"Chez Scheme is a self-hosting compiler: building it requires
-``bootfiles'' containing the Scheme-implemented portions compiled for the
+``boot files'' containing the Scheme-implemented portions compiled for the
current platform. (Chez can then cross-compile bootfiles for all other
supported platforms.)
-This package provides bootstrap bootfiles for upstream Chez Scheme.
-Currently, it simply packages the binaries checked in to the upstream
-repository. Hopefully we can eventually adapt Racket's @code{cs-bootstrap} to
-work with upstream Chez Scheme so that we can bootstrap these files from
-source.")))
+This package provides boot files for the released version of Chez Scheme
+bootstrapped by @code{chez-scheme-for-racket}. Chez Scheme 9.5.4 or any later
+version can be used for bootstrapping. Guix ultimately uses the Racket package
+@code{cs-bootstrap} to bootstrap its initial version of Chez Scheme.")
+ (license asl2.0)))
;;
;; Chez's bootstrap dependencies:
@@ -72,6 +72,7 @@ (define-module (gnu packages racket)
;; ├── bc/
;; ├── cs/
;; ├── ChezScheme/
+;; ├── rktboot/
;; ├── zuo/
;; └── ...
;;
@@ -149,14 +150,12 @@ (define-module (gnu packages racket)
;; - Racket BC [3M] needs an existing Racket to run "xform",
;; which transforms its own C source code to add additional annotations
;; for the precise garbage collector.
-;; - Racket CS needs (bootfiles for) Racket's fork of Chez Scheme.
-;; It also needs an existing Racket to compile Racket-implemented
+;; - Racket CS needs (boot files for) the corresponding version of Chez
+;; Scheme. It also needs an existing Racket to compile Racket-implemented
;; parts of the runtime system to R6RS libraries.
-;; - Chez Scheme also needs bootfiles for itself, but Racket can simulate
-;; enough of Chez Scheme to load Racket's fork of the Chez Scheme compiler
-;; purely from source into Racket and apply the compiler to itself,
-;; producing the needed bootfiles (albeit very slowly).
-;; Any variant of Racket since version 7.1 can run the simulation.
+;; - Chez Scheme also needs boot files for itself, but Racket BC can
+;; bootstrap these using the code in "racket/src/rktboot/".
+;; See the commentary in "chez.scm" for further details
;;
;; So, we build CGC to build 3M to build bootfiles and CS.
;;
@@ -164,6 +163,14 @@ (define-module (gnu packages racket)
;; often use "BC" to mean "3M", consistent with `(banner)` and the
;; suffixes used on executables when more than one variant co-exists.)
;;
+;; Since the pre-releases for Chez Scheme 10.0.0, all of Racket's changes have
+;; been merged upstream, and development will be kept in sync going
+;; forward. However, there is no plan to align the Chez Scheme and Racket
+;; release cycles. For the near fulture, a given released version of Racket
+;; will continue to depend on a specific pre-release version of Chez Scheme as
+;; part of Racket CS's "ABI". See upstream discussion at
+;; <https://racket.discourse.group/t/2739/3>.
+;;
;; One remaining bootstrapping limitation is that Racket's reader, module
;; system, and macro expander are implemented in Racket. For Racket CS,
;; they are compiled to R6RS libraries as discussed above. This note from the
@@ -189,7 +196,8 @@ (define-module (gnu packages racket)
;; Zuo is notably *not* a problem for bootstrapping. The implementation is a
;; single hand-written C file designed to build with just `cc -o zuo zuo.c`,
;; even with very old or limited compilers. (We use the Autoconf support for
-;; convienience.)
+;; convienience.) As of Zuo 1.8, Zuo has tagged releases in its own repository
+;; independent of the Racket release cycle.
;;
;; CODE: