;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2016 Federico Beffa <beffa@fbengineering.ch>
;;; Copyright © 2016 Efraim Flashner <efraim@flashner.co.il>
;;; Copyright © 2017, 2019 Tobias Geerinckx-Rice <me@tobias.gr>
;;; Copyright © 2019 Brett Gilio <brettg@gnu.org>
;;; Copyright © 2020 Brendan Tildesley <mail@brendan.scot>
;;; Copyright © 2021, 2022 Philip McGrath <philip@philipmcgrath.com>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; GNU Guix is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.

(define-module (gnu packages chez-and-racket-bootstrap)
  #:use-module (guix packages)
  #:use-module (guix download)
  #:use-module (guix git-download)
  #:use-module (guix utils)
  #:use-module (guix gexp)
  #:use-module (ice-9 match)
  #:use-module (ice-9 regex)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-26)
  #:use-module (guix build-system copy)
  #:use-module (guix build-system gnu)
  #:use-module (gnu packages)
  #:use-module (gnu packages compression)
  #:use-module (gnu packages ghostscript)
  #:use-module (gnu packages linux)
  #:use-module (gnu packages ncurses)
  #:use-module (gnu packages netpbm)
  #:use-module (gnu packages tex)
  #:use-module (gnu packages xorg)
  #:use-module ((guix licenses)
                #:prefix license:))

;; Commentary:
;;
;; Alphabetically and chronologically, Chez comes before Racket.
;;
;; 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.
;;
;; 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.
;;
;; Putting the relevant definitions together in this module avoids having to
;; work around dependency cycles.
;;
;; Code:

(define (chez-machine->unthreaded mach)
  "Given a string MACH naming a Chez Scheme machine type, returns a string
naming the unthreaded machine type for the same architecture and OS as MACH.
The returned string may share storage with MACH."
  (if (eqv? #\t (string-ref mach 0))
      (substring mach 1)
      mach))
(define (chez-machine->threaded mach)
  "Like @code{chez-machine->unthreaded}, but returns the threaded machine
type."
  (if (eqv? #\t (string-ref mach 0))
      mach
      (string-append "t" mach)))

;; 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->upstream-restriction mach)
  "Given a string MACH naming a Chez Scheme machine type, returns a symbol
naming a restriction on the upstream Chez Scheme implementation compared to
the Racket variant, or @code{#f} if no such restriction exists.  The
restriction is reported for the architecture--OS pair, regardless of whether
MACH specifies a threaded or an unthreaded variant.

Possible restrictions currently include:
@itemize @bullet
@item
@code{'no-threads}: Support for native threads is not available upstream.
@item
@code{'no-support}: The upstream release doesn't claim to support this
architecture--OS combination at all.
@end itemize

See @code{chez-machine->nix-system} for more details about acceptable values
for MACH."
  (let ((mach (chez-machine->unthreaded mach)))
    (cond
     ((string-prefix? "arm64" mach)
      'no-support)
     ((string-prefix? "arm32" mach)
      (if (string-suffix? "le" mach)
          'no-threads
          'no-support))
     ((string-prefix? "ppc32" mach)
      (if (string-suffix? "le" mach)
          #f
          'no-support))
     (else
      #f))))

(define (chez-machine->nix-system mach)
  "Return the Nix system type corresponding to the Chez Scheme machine type
MACH.  If MACH is not a string representing a known machine type, an exception
is raised.  This function does not distinguish between threaded and unthreaded
variants of MACH.

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 the 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 ((mach (chez-machine->unthreaded mach)))
    (let find-arch ((alist %nix-arch-to-chez-alist))
      (match alist
        (((nix . chez) . alist)
         (if (string-prefix? chez mach)
             (string-append
              nix "-" (let ((mach-os (substring mach (string-length chez))))
                        (let find-os ((alist %nix-os-to-chez-alist))
                          (match alist
                            (((nix . chez) . alist)
                             (if (equal? chez mach-os)
                                 nix
                                 (find-os alist)))))))
             (find-arch alist)))))))

(define* (nix-system->chez-machine #:optional (system (%current-system))
                                   #:key (threads? 'always))
  "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.

When THREADS? is @code{'always} (the default), the threaded variant of the
machine type will be returned: note that the package returned by
@code{chez-scheme-for-system} will always support native threads.  When
THREADS? is @code{#f}, the unthreaded machine type will be returned.  If
THREADS? is @code{'upstream} (the default), the threaded variant of the
machine type will be returned if and only if it is supported by upstream Chez
Scheme (see @code{chez-machine->upstream-restriction}).  If THREADS? is any
other value, an exception is raised."
  (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))
         (mach (and chez-arch chez-os (string-append chez-arch chez-os))))
    (and mach
         (match threads?
           ('always
            (chez-machine->threaded mach))
           (#f
            mach)
           ('upstream
            (if (chez-machine->upstream-restriction mach)
                mach
                (chez-machine->threaded mach)))))))

;;
;; Chez Scheme:
;;

(define unbundle-chez-submodules
  #~(begin
      (use-modules (guix build utils))
      (for-each (lambda (dir)
                (when (directory-exists? dir)
                  (delete-file-recursively dir)))
              '("stex"
                "nanopass"
                "lz4"
                "zlib"))))

(define unpack-nanopass+stex
  #~(begin
      (copy-recursively
       (dirname (search-input-file %build-inputs
                                   "lib/chez-scheme/nanopass.ss"))
       "nanopass"
       #:keep-mtime? #t)
      (mkdir-p "stex")
      (with-output-to-file "stex/Mf-stex"
        (lambda ()
          ;; otherwise, it will try to download submodules
          (display "# to placate ../configure")))))

(define-public chez-scheme-bootstrap-bootfiles
  (package
    (name "chez-scheme-bootstrap-bootfiles")
    ;; The version should match `(scheme-version-number)`.
    ;; See s/cmacros.ss c. line 360.
    (version "9.5.6")
    (source (origin
              (method git-fetch)
              (uri (git-reference
                    (url "https://github.com/cisco/ChezScheme")
                    (commit (string-append "v" version))))
              (sha256
               (base32
                "07s433hn1z2slfc026sidrpzxv3a8narcd40qqr1xrpb9012xdky"))
              (file-name (git-file-name "chez-scheme" version))
              (snippet unbundle-chez-submodules)))
    (build-system copy-build-system)
    ;; TODO: cross compilation
    (arguments
     (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 ((mach (nix-system->chez-machine system #:threads? #f)))
                 (or (equal? "arm32le" mach)
                     (and mach
                          (member (substring mach 0 2) '("i3" "a6"))
                          (or-map (cut string-suffix? <> mach)
                                  '("le" "nt" "osx"))))))
             %supported-systems))
    (home-page "https://cisco.github.io/ChezScheme/")
    (synopsis "Chez Scheme bootfiles (binary seed)")
    (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
supported platforms.)

This package provides bootstrap bootfiles for upstream Chez Scheme.
Currently, it simply packages the binaries checked in to the upsream
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.")
    (properties `((hidden? . #t)))
    (license license:asl2.0)))

(define-public chez-scheme
  (package
    (name "chez-scheme")
    (version (package-version chez-scheme-bootstrap-bootfiles))
    (source (package-source chez-scheme-bootstrap-bootfiles))
    (build-system gnu-build-system)
    (inputs
     (list
      `(,util-linux "lib") ;<-- libuuid
      zlib
      lz4
      ncurses ;<-- for expeditor
      ;; for X11 clipboard support in expeditor:
      ;; https://github.com/cisco/ChezScheme/issues/9#issuecomment-222057232
      libx11))
    (native-inputs (list chez-scheme-bootstrap-bootfiles
                         chez-nanopass-bootstrap
                         stex-bootstrap))
    (native-search-paths
     (list (search-path-specification
            (variable "CHEZSCHEMELIBDIRS")
            (files (list (string-append "lib/chez-scheme"))))))
    (outputs '("out" "doc"))
    (arguments
     (list
      #:modules
      '((guix build gnu-build-system)
        (guix build utils)
        (ice-9 ftw)
        (ice-9 match))
      #:test-target "test"
      ;; TODO when we fix armhf, it may not support --threads
      #:configure-flags #~'("--threads")
      #:phases
      #~(modify-phases %standard-phases
          (add-after 'unpack 'unpack-nanopass+stex
            (lambda args
              #$unpack-nanopass+stex))
          (add-after 'unpack-nanopass+stex 'unpack-bootfiles
            (lambda* (#:key native-inputs inputs #:allow-other-keys)
              (when (directory-exists? "boot")
                (delete-file-recursively "boot"))
              (copy-recursively
               (search-input-directory (or native-inputs inputs)
                                       "lib/chez-scheme-bootfiles")
               "boot")))
          ;; NOTE: the custom Chez 'configure' script doesn't allow
          ;; unrecognized flags, such as those automatically added
          ;; by `gnu-build-system`.
          (replace 'configure
            (lambda* (#:key inputs (configure-flags '()) #:allow-other-keys)
              ;; add flags which are always required:
              (let ((flags (cons* (string-append "--installprefix=" #$output)
                                  "ZLIB=-lz"
                                  "LZ4=-llz4"
                                  "--libkernel"
                                  ;; Guix will do compress-man-pages,
                                  ;; and letting Chez try causes an error
                                  "--nogzip-man-pages"
                                  configure-flags)))
                (format #t "configure flags: ~s~%" flags)
                ;; Some makefiles (for tests) don't seem to propagate CC
                ;; properly, so we take it out of their hands:
                (setenv "CC" #$(cc-for-target))
                (setenv "HOME" "/tmp")
                (apply invoke "./configure" flags))))
          ;; The binary file name is called "scheme" as is the one from
          ;; MIT/GNU Scheme.  We add a symlink to use in case both are
          ;; installed.
          (add-after 'install 'install-symlink
            (lambda* (#:key outputs #:allow-other-keys)
              (let* ((scheme (search-input-file outputs "/bin/scheme"))
                     (bin-dir (dirname scheme)))
                (symlink scheme
                         (string-append bin-dir "/chez-scheme"))
                (match (find-files (string-append bin-dir "/../lib")
                                   "scheme.boot")
                  ((scheme.boot)
                   (symlink scheme.boot
                            (string-append (dirname scheme.boot)
                                           "/chez-scheme.boot")))))))
          ;; Building the documentation requires stex and a running scheme.
          ;; FIXME: this is probably wrong for cross-compilation
          (add-after 'install-symlink 'install-doc
            (lambda* (#:key native-inputs inputs outputs
                            #:allow-other-keys)
              (match (assoc-ref outputs "doc")
                (#f
                 (format #t "not installing docs~%"))
                (doc-prefix
                 (let* ((chez+version (strip-store-file-name #$output))
                        (scheme (search-input-file outputs "/bin/scheme"))
                        (stexlib (search-input-directory
                                  (or native-inputs inputs)
                                  "/lib/stex"))
                        (doc-dir (string-append doc-prefix
                                                "/share/doc/"
                                                chez+version)))
                   (define* (stex-make #:optional (suffix ""))
                     (invoke "make" "install"
                             (string-append "Scheme=" scheme)
                             (string-append "STEXLIB=" stexlib)
                             (string-append "installdir="
                                            doc-dir suffix)))
                   (with-directory-excursion "csug"
                     (stex-make "/csug"))
                   (with-directory-excursion "release_notes"
                     (stex-make "/release_notes"))
                   (with-directory-excursion doc-dir
                     (symlink "release_notes/release_notes.pdf"
                              "release_notes.pdf")
                     (symlink "csug/csug9_5.pdf"
                              "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
      (filter
       (lambda (system)
         (and=> (nix-system->chez-machine system)
                (lambda (mach)
                  (not (eq? 'no-support
                            (chez-machine->upstream-restriction mach))))))
       %supported-systems)))
    (home-page (package-home-page chez-scheme-bootstrap-bootfiles))
    (synopsis "R6RS Scheme compiler and run-time")
    (description
     "Chez Scheme is a compiler and run-time system for the language of the
Revised^6 Report on Scheme (R6RS), with numerous extensions.  The compiler
generates native code for each target processor, with support for x86, x86_64,
and 32-bit PowerPC architectures.")
    (license license:asl2.0)))

;;
;; Chez's bootstrap dependencies:
;;

(define-public stex-bootstrap
  ;; This commit includes a fix which we would otherwise want to use as
  ;; patch.  Let's revert to tagged releases as soon as one becomes available.
  (let ((commit "54051494434a197772bf6ca5b4e6cf6be55f39a5")
        (revision "1"))
    (hidden-package
     (package
       (name "stex")
       ;; ^ Debian calls this "stex", not "chez-stex". It is a set of
       ;; command-line tools, and there isn't a Scheme API, let alone a
       ;; Chez-specific one, except perhaps that the Scheme examples are
       ;; assumed to be Chez-compatible.
       (version (git-version "1.2.2" revision commit))
       (source
        (origin
          (method git-fetch)
          (uri (git-reference
                (url "https://github.com/dybvig/stex")
                (commit commit)))
          (sha256
           (base32 "01jnvw8qw33gnpzwrakwhsr05h6b609lm180jnspcrb7lds2p23d"))
          (file-name (git-file-name name version))
          (snippet
           #~(for-each delete-file
                       '("sbin/install" "doc/stex.pdf" "doc/stex.html")))))
       (outputs '("out"))
       (build-system copy-build-system)
       ;; N.B. Upstream does not seem to support cross-compilation,
       ;; though it would probably be easy to add.
       (propagated-inputs
        (list xorg-rgb
              (texlive-updmap.cfg
               (list texlive-dvips-l3backend
                     texlive-hyperref
                     texlive-bibtex
                     texlive-epsf
                     texlive-fonts-ec
                     texlive-oberdiek))
              ghostscript
              netpbm))
       ;; Debian uses a versionless path for STEXLIB,
       ;; which is much more convienient.
       (arguments
        (list
         #:install-plan #~`(("inputs" "lib/stex/")
                            ("gifs" "lib/stex/")
                            ("math" "lib/stex/")
                            ("src" "lib/stex/") ;; can run without compiling
                            ("Mf-stex" "lib/stex/")
                            ("Makefile.template" "lib/stex/"))
         #:phases
         #~(modify-phases %standard-phases
             (add-before 'install 'patch-sources
               (lambda* (#:key native-inputs inputs outputs #:allow-other-keys)
                 (define scheme
                   (false-if-exception
                    (search-input-file inputs "/bin/scheme")))
                 (when scheme
                   (setenv "Scheme" scheme))
                 (substitute* '("Makefile.template"
                                "doc/Makefile")
                   (("STEXLIB=[^\n]*")
                    (string-append "STEXLIB=" #$output "/lib/stex"))
                   (("Scheme=[^\n]*")
                    (string-append "Scheme=" (or scheme "scheme"))))
                 (substitute* '("Mf-stex"
                                "math/Makefile")
                   (("/bin/rm")
                    "rm"))
                 (substitute* "Mf-stex"
                   (("SHELL=bash")
                    ;; avoid Solaris workaround
                    "#SHELL=bash"))))
             (add-after 'install 'maybe-compile
               (lambda* (#:key native-inputs inputs outputs #:allow-other-keys)
                 (cond
                  ((getenv "Scheme")
                   => (lambda (scheme)
                        (define makefile
                          (string-append (getcwd) "/Makefile"))
                        (define machine
                          (let ((machine #$(nix-system->chez-machine
                                            (or (%current-target-system)
                                                (%current-system)))))
                            (if (and (not (eqv? #\t (string-ref machine 0)))
                                     (string-contains scheme "racket"))
                                (string-append "t" machine)
                                machine)))
                        (with-directory-excursion
                            (search-input-directory outputs "/lib/stex")
                          (invoke "make"
                                  "-f" makefile
                                  (string-append "Scheme=" scheme))
                          (for-each delete-file
                                    (find-files machine
                                                "\\.")))))
                  (else
                   (format #t "not compiling~%")))))
             (add-after 'maybe-compile 'maybe-make-docs
               (lambda* (#:key native-inputs inputs outputs #:allow-other-keys)
                 (cond
                  ((assoc-ref outputs "doc")
                   => (lambda (doc-prefix)
                        (define doc-dir
                          (string-append doc-prefix "/share/doc/stex"))
                        ;; the Makefile is considered part of the documentation
                        (copy-recursively "doc" doc-dir)
                        (install-file "ReadMe" doc-dir)
                        (with-directory-excursion "doc"
                          (invoke "make")
                          (install-file "stex.html" doc-dir)
                          (install-file "stex.pdf" doc-dir))))
                  (else
                   (format #t "not making docs~%"))))))))
       (home-page "https://github.com/dybvig/stex")
       (synopsis "LaTeX with embeded Scheme code and HTML generation")
       (description "The @code{stex} package extends LaTeX with a handful of
commands for including Scheme code (or pretty much any other kind of code, as
long as you don't plan to use the Scheme-specific transcript support) in a
document.  It provides the programs @code{scheme-prep} and @code{html-prep} to
convert @code{stex} documents to LaTeX and HTML, respectively, plus makefile
templates, style files, and other resources.  The @code{stex} system is used
to typeset @cite{The Scheme Programming Language} and the @cite{Chez Scheme
User's Guix}, among other documents.")
       (license license:expat)))))

(define-public stex
  (package/inherit stex-bootstrap
    (inputs (modify-inputs (package-inputs stex-bootstrap)
              (prepend chez-scheme)))
    (outputs '("out" "doc"))
    (properties '())))

(define-public chez-nanopass-bootstrap
  (hidden-package
   (package
     (name "chez-nanopass")
     (version "1.9.2")
     (source
      (origin
        (method git-fetch)
        (uri (git-reference
              (url "https://github.com/nanopass/nanopass-framework-scheme")
              (commit (string-append "v" version))))
        (sha256 (base32 "16vjsik9rrzbabbhbxbaha51ppi3f9n8rk59pc6zdyffs0vziy4i"))
        (file-name (git-file-name "nanopass-framework-scheme" version))
        (snippet
         #~(begin
             (use-modules (guix build utils))
             (when (file-exists? "doc/user-guide.pdf")
               (delete-file "doc/user-guide.pdf"))
             (substitute* "doc/Makefile"
               (("include ~/stex/Mf-stex")
                "include $(STEXLIB)/Mf-stex"))))))
     (build-system copy-build-system)
     (arguments
      (list #:install-plan
            #~`(("nanopass.ss" "lib/chez-scheme/")
                ("nanopass" "lib/chez-scheme/"))))
     (home-page "https://nanopass.org")
     (synopsis "DSL for compiler development")
     (description "The Nanopass framework is an embedded domain-specific
language for writing compilers composed of several simple passes that
operate over well-defined intermediate languages.  The goal of this
organization is both to simplify the understanding of each pass, because it
is responsible for a single task, and to simplify the addition of new passes
anywhere in the compiler.  Nanopass reduces the boilerplate required to
create compilers, making them easier to understand and maintain.")
     (license license:expat))))

(define-public chez-nanopass
  (package/inherit chez-nanopass-bootstrap
    (properties '())
    ;; TODO: cross-compilation
    (native-inputs (list chez-scheme stex))
    (arguments
     (substitute-keyword-arguments (package-arguments chez-nanopass-bootstrap)
       ((#:install-plan base-plan)
        #~`(("nanopass.so" "lib/chez-scheme/")
            ("doc/user-guide.pdf" #$(string-append
                                     "share/doc/"
                                     (package-name this-package)
                                     "-"
                                     (package-version this-package)
                                     "/"))
            ,@#$base-plan))
       ((#:phases base-phases #~%standard-phases)
        #~(modify-phases #$base-phases
            (add-before 'install 'compile-and-test
              (lambda args
                (invoke "scheme"
                        "--compile-imported-libraries"
                        "--program" "test-all.ss")))
            (add-after 'compile-and-test 'build-doc
              (lambda* (#:key native-inputs inputs #:allow-other-keys)
                (with-directory-excursion "doc"
                  (invoke "make"
                          (string-append "Scheme="
                                         (search-input-file
                                          (or native-inputs inputs)
                                          "/bin/scheme"))
                          (string-append "STEXLIB="
                                         (search-input-directory
                                          (or native-inputs inputs)
                                          "/lib/stex"))))))))))))