Package: guix-patches;
Reported by: Philip McGrath <philip <at> philipmcgrath.com>
Date: Tue, 3 May 2022 18:32:01 UTC
Severity: normal
Tags: patch
Done: Ludovic Courtès <ludo <at> gnu.org>
Bug is archived. No further changes may be made.
Message #35 received at 55248 <at> debbugs.gnu.org (full text, mbox):
From: Liliana Marie Prikler <liliana.prikler <at> ist.tugraz.at> To: Philip McGrath <philip <at> philipmcgrath.com>, 55248 <at> debbugs.gnu.org Subject: Re: [PATCH 7/7] gnu: chez-scheme-for-system: Adjust support logic. Date: Wed, 04 May 2022 09:21:00 +0200
Am Dienstag, dem 03.05.2022 um 14:33 -0400 schrieb Philip McGrath:
> This is a follow-up to commit
> b8fc9169515ef1a6d6037c84e30ad308e5418b6f:
> see <https://issues.guix.gnu.org/54292>. Thanks to Liliana Marie
> Prikler for pointing out various issues, e.g. that being able to
> represent a Nix system as a Chez Scheme machine type does not
> necessarily mean the system is supported!
The issue in that commit is a different one: nix-system->chez-machine
can fail if there's no conversion. Anyway...
> [...]
> ;; Commentary:
> @@ -73,96 +71,17 @@ (define* (chez-scheme-for-system #:optional
> (%current-system))))
> "Return 'chez-scheme' unless only 'chez-scheme-for-racket'
> supports SYSTEM,
> including support for native threads."
> - (if (or
> - ;; full support upstream
> - (and=> (chez-upstream-features-for-system system)
> - (cut memq 'threads <>))
> - ;; no support anywhere
> - (not (nix-system->chez-machine system)))
> + (if (and=> (chez-upstream-features-for-system system)
> + (lambda (features)
> + (every (cut memq <> features)
> + '(threads
> + ;; We can cross-compile for platforms
> without
> + ;; bootstrap bootfiles, but we can't self-
> host
> + ;; on them short of adding more binary
> seeds.
> + bootstrap-bootfiles))))
> chez-scheme
> chez-scheme-for-racket))
Does it make sense to require 'threads always?
>
> -(define (chez-machine->nonthreaded machine)
> - "Given a string MACHINE naming a Chez Scheme machine type, returns
> a string
> -naming the nonthreaded machine type for the same architecture and OS
> as
> -MACHINE. The returned string may share storage with MACHINE."
> - ;; Chez Scheme documentation consistently uses "nonthreaded"
> rather than
> - ;; e.g. "unthreaded"
> - (if (eqv? #\t (string-ref machine 0))
> - (substring machine 1)
> - machine))
> -(define (chez-machine->threaded machine)
> - "Like @code{chez-machine->nonthreaded}, but returns the threaded
> machine
> -type."
> - (if (eqv? #\t (string-ref machine 0))
> - machine
> - (string-append "t" machine)))
> -
> -;; Based on the implementation from raco-cross-
> lib/private/cross/platform.rkt
> -;; in https://github.com/racket/raco-cross.
> -;; For supported platforms, refer to
> release_notes/release_notes.stex in the
> -;; upstream Chez Scheme repository or to
> racket/src/ChezScheme/README.md
> -;; in https://github.com/racket/racket.
> -(define %nix-arch-to-chez-alist
> - `(("x86_64" . "a6")
> - ("i386" . "i3")
> - ("aarch64" . "arm64")
> - ("armhf" . "arm32") ;; Chez supports ARM v6+
> - ("ppc" . "ppc32")))
> -(define %nix-os-to-chez-alist
> - `(("w64-mingw32" . "nt")
> - ("darwin" . "osx")
> - ("linux" . "le")
> - ("freebsd" . "fb")
> - ("openbsd" . "ob")
> - ("netbsd" . "nb")
> - ("solaris" . "s2")))
> -
> -(define (chez-machine->nix-system machine)
> - "Return the Nix system type corresponding to the Chez Scheme
> machine type
> -MACHINE. If MACHINE is not a string representing a known machine
> type, an
> -exception is raised. This function does not distinguish between
> threaded and
> -nonthreaded variants of MACHINE.
> -
> -Note that this function only handles Chez Scheme machine types in
> the
> -strictest sense, not other kinds of descriptors sometimes used in
> place of a
> -Chez Scheme machine type by Racket, such as @code{\"pb\"},
> @code{#f}, or
> -@code{\"racket\"}. (When using such extensions, the Chez Scheme
> machine type
> -for the host system is often still relevant.)"
> - (let ((machine (chez-machine->nonthreaded machine)))
> - (let find-arch ((alist %nix-arch-to-chez-alist))
> - (match alist
> - (((nix . chez) . alist)
> - (if (string-prefix? chez machine)
> - (string-append
> - nix "-" (let ((machine-os
> - (substring machine (string-length
> chez))))
> - (let find-os ((alist %nix-os-to-chez-alist))
> - (match alist
> - (((nix . chez) . alist)
> - (if (equal? chez machine-os)
> - nix
> - (find-os alist)))))))
> - (find-arch alist)))))))
> -
> -(define* (nix-system->chez-machine #:optional
> - (system (or (%current-target-
> system)
> - (%current-system))))
> - "Return the Chez Scheme machine type corresponding to the Nix
> system
> -identifier SYSTEM, or @code{#f} if the translation of SYSTEM to a
> Chez Scheme
> -machine type is undefined.
> -
> -It is unspecified whether the resulting string will name a threaded
> or a
> -nonthreaded machine type: when the distinction is relevant, use
> -@code{chez-machine->nonthreaded} or @code{chez-machine->threaded} to
> adjust
> -the result."
> - (let* ((hyphen (string-index system #\-))
> - (nix-arch (substring system 0 hyphen))
> - (nix-os (substring system (+ 1 hyphen)))
> - (chez-arch (assoc-ref %nix-arch-to-chez-alist nix-arch))
> - (chez-os (assoc-ref %nix-os-to-chez-alist nix-os)))
> - (and chez-arch chez-os (string-append chez-arch chez-os))))
> -
The replacement code should go here for readability imho. At the very
least I was confused why this was first above and now below.
> (define* (chez-upstream-features-for-system #:optional
> (system
> (or (%current-target-
> system)
> @@ -172,20 +91,150 @@ (define* (chez-upstream-features-for-system
> #:optional
> does not support SYSTEM at all.
>
> If native threads are supported, the returned list will include
> -@code{'threads}. Other feature symbols may be added in the future."
> +@code{'threads}. If bootstrap bootfiles for SYSTEM are distributed
> in the
> +upstream Chez Scheme repository, the returned list will include
> +@code{'bootstrap-bootfiles}. Other feature symbols may be added in
> the
> +future."
> + (let ((chez-arch (target-chez-arch system))
> + (chez-os (target-chez-os system)))
> + (and=> (assoc-ref %chez-features-table chez-os)
> + (cut assoc-ref <> chez-arch))))
> +
> +(define* (racket-cs-native-supported-system? #:optional
> + (system
> + (or (%current-target-
> system)
> + (%current-
> system))))
> + "Can Racket's variant of Chez Scheme generate native code for
> SYSTEM?
> +Otherwise, SYSTEM can use only the ``portable bytecode'' backends."
> + (let ((chez-arch (target-chez-arch system))
> + (chez-os (target-chez-os system)))
> + (and (and=> (assoc-ref %chez-features-table chez-os)
> + ;; NOT assoc-ref: supported even if cdr is #f
> + (cut assoc chez-arch <>))
> + #t)))
> +
> +(define %chez-features-table
> + ;; An alist of alists mapping:
> + ;; os -> arch -> (or/c #f (listof symbol?))
> + ;; where:
> + ;; - `os` is a string for the OS part of a Chez Scheme machine
> type; and
> + ;; - `arch` is a string for the architecture part of a Chez
> machine type.
> + ;;
> + ;; The absence of an entry for a given arch--os pair means that
> neither
> + ;; upstream Chez Scheme nor the Racket variant can generate native
> code for
> + ;; that system. (The Racket variant can still provide support via
> its
> + ;; ``portable bytecode'' backends and optional compilation to C.)
> A value
> + ;; of `#f` means that upstream Chez Scheme does not support the
> arch--os
> + ;; pair at all, but the Racket variant does. A list has the same
> meaning as
> + ;; a result from `chez-upstream-features-for-system`.
> + ;;
> + ;; The arch--os pairs marked "commented out" have been commented
> out in the
> + ;; STeX source for the upstream release notes since the initial
> release as
> + ;; free software, but they are reported to work and/or have been
> described
> + ;; as supported by upstream maintainers.
> + ;;
> + ;; For this overall approach to make sense, we assume that
> Racket's variant
> + ;; of Chez Scheme can generate native code for a superset of the
> platforms
> + ;; supported upstream, supports threads on all platforms it
> supports at all
> + ;; (because they are needed for Racket), and doesn't need
> bootstrap
> + ;; bootfiles. Those assumptions have held for several years.
> + '(;; Linux
> + ("le"
> + ("i3" threads bootstrap-bootfiles)
> + ("a6" threads bootstrap-bootfiles)
> + ("arm32" bootstrap-bootfiles)
> + ("arm64" . #f)
> + ("ppc32" threads))
> + ;; FreeBSD
> + ("fb"
> + ("i3" threads) ;; commented out
> + ("a6" threads) ;; commented out
> + ("arm32" . #f)
> + ("arm64" . #f)
> + ("ppc32" . #f))
> + ;; OpenBSD
> + ("ob"
> + ("i3" threads) ;; commented out
> + ("a6" threads) ;; commented out
> + ("arm32" . #f)
> + ("arm64" . #f)
> + ("ppc32" . #f))
> + ;; NetBSD
> + ("nb"
> + ("i3" threads) ;; commented out
> + ("a6" threads) ;; commented out
> + ("arm32" . #f)
> + ("arm64" . #f)
> + ("ppc32" . #f))
> + ;; OpenSolaris / OpenIndiana / Illumos
> + ("s2"
> + ("i3" threads) ;; commented out
> + ("a6" threads)) ;; commented out
> + ;; Windows
> + ("nt"
> + ("i3" threads bootstrap-bootfiles)
> + ("a6" threads bootstrap-bootfiles)
> + ;; ^ threads "experiemental", but reportedly fine
> + ("arm64" . #f))
> + ;; Darwin
> + ("osx"
> + ("i3" threads bootstrap-bootfiles)
> + ("a6" threads bootstrap-bootfiles)
> + ("arm64" . #f)
> + ("ppc32" . #f))))
> +
> +(define* (target-chez-arch #:optional (system
> + (or (%current-target-system)
> + (%current-system))))
> + "Return a string representing the architecture of SYSTEM as used
> in Chez
> +Scheme machine types, or '#f' if none is defined."
> (cond
> - ((not (nix-system->chez-machine system))
> - #f)
> + ((target-x86-64? system)
> + "a6")
> + ((target-x86-32? system)
> + "i3")
> ((target-aarch64? system)
> - #f)
> + "arm64")
> ((target-arm32? system)
> - (and (target-linux? system)
> - '()))
> + "arm32")
> + ((target-ppc64le? system)
> + #f)
> ((target-ppc32? system)
> - (and (target-linux? system)
> - '(threads)))
> + "ppc32")
> + ((target-riscv64? system)
> + #f)
> (else
> - '(threads))))
> + #f)))
> +
> +(define* (target-chez-os #:optional (system (or (%current-target-
> system)
> + (%current-system))))
> + "Return a string representing the operating system kernel of
> SYSTEM as used
> +in Chez Scheme machine types, or '#f' if none is defined."
> + ;; e.g. "le" includes both GNU/Linux and Android
> + (cond
> + ((target-linux? system)
> + "le")
> + ((target-hurd? system)
> + #f)
> + ((target-mingw? system)
> + "nt")
> + ;; missing (guix utils) predicates
> + ;; cf.
> https://github.com/NixOS/nixpkgs/blob/master/lib/systems/doubles.nix
> + ((string-suffix? "-darwin" system)
> + "osx")
> + ((string-suffix? "-freebsd" system)
> + "fb")
> + ((string-suffix? "-openbsd" system)
> + "ob")
> + ((string-suffix? "-netbsd" system)
> + "nb")
> + ;; Nix says "x86_64-solaris", but accommodate "-solaris2"
> + ((string-contains system "solaris")
> + "s2")
> + ;; unknown
> + (else
> + #f)))
> +
For the sake of completeness, we might want to still have nix-system-
>chez-machine (with a threaded? argument) defined in terms of target-
chez-arch and target-chez-os. See 6/7 for motivation.
>
> ;;
> ;; Chez Scheme:
> @@ -365,14 +414,9 @@ (define-public chez-scheme
> ((pth)
> (symlink pth
> "csug.pdf")))))))))
> - ;; Chez Scheme does not have a MIPS backend.
> - ;; FIXME: Debian backports patches to get armhf working.
> - ;; We should too. It is the Chez machine type arm32le
> - ;; (no threaded version upstream yet, though there is in
> - ;; Racket's fork), more specifically (per the release notes)
> ARMv6.
> (supported-systems
> (delete
> - "armhf-linux" ;; <-- should work, but reportedly broken
> + "armhf-linux" ;; XXX is this still broken?
I'd say "XXX: reportedly broken, needs checking"
> (filter chez-upstream-features-for-system
> %supported-systems)))
> (home-page "https://cisco.github.io/ChezScheme/")
> @@ -418,7 +462,9 @@ (define-public chez-scheme-for-racket
> (add-after 'unpack 'chdir
> (lambda args
> (chdir "racket/src/ChezScheme"))))))))
> - (supported-systems (filter nix-system->chez-machine
> + ;; TODO: How to build pbarch/pbchunks for other systems?
> + ;; See https://racket.discourse.group/t/950
> + (supported-systems (filter racket-cs-native-supported-system?
> %supported-systems))
> (home-page "https://github.com/racket/ChezScheme")
> ;; ^ This is downstream of https://github.com/racket/racket,
> @@ -471,16 +517,9 @@ (define-public chez-scheme-bootstrap-bootfiles
> (list #:install-plan
> #~`(("boot/" "lib/chez-scheme-bootfiles"))))
> (supported-systems
> - ;; Upstream only distributes pre-built bootfiles for
> - ;; arm32le and t?(i3|a6)(le|nt|osx)
> (filter (lambda (system)
> - (let ((machine (and=> (nix-system->chez-machine
> system)
> - chez-machine->nonthreaded)))
> - (or (equal? "arm32le" machine)
> - (and machine
> - (member (substring machine 0 2) '("i3"
> "a6"))
> - (or-map (cut string-suffix? <> machine)
> - '("le" "nt" "osx"))))))
> + (and=> (chez-upstream-features-for-system system)
> + (cut memq 'bootstrap-bootfiles <>)))
Yup, that's simpler.
> %supported-systems))
> (synopsis "Chez Scheme bootfiles (binary seed)")
> (description
> diff --git a/gnu/packages/racket.scm b/gnu/packages/racket.scm
> index 2f4f7cebd8..41f45f4215 100644
> --- a/gnu/packages/racket.scm
> +++ b/gnu/packages/racket.scm
> @@ -190,8 +190,11 @@ (define-module (gnu packages racket)
> (define* (racket-vm-for-system #:optional
> (system (or (%current-target-system)
> (%current-system))))
> - "Return 'racket-vm-cs' if it supports SYSTEM; 'racket-vm-bc'
> otherwise."
> - (if (nix-system->chez-machine system)
> + "Return 'racket-vm-cs' we are able to build it for SYSTEM;
> 'racket-vm-bc'
> +otherwise."
> + ;; Once we figure out the issues in
> https://racket.discourse.group/t/950,
> + ;; we can use 'racket-vm-cs' everywhere.
> + (if (racket-cs-native-supported-system? system)
> racket-vm-cs
> racket-vm-bc))
All in all, the individual logic of this patch seems fine, but overall
it appears as though it's doing three separate things (chez-scheme-for-
system, chez features, racket-cs stuff). IMO it would make sense to
split this patch according to those lines. WDYT?
Patches 2-5 mostly LGTM, at least I don't see any glaring issues in
this iteration.
Cheers
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