[jackhill/guix/guix.git] / guix / self.scm

;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2017, 2018, 2019 Ludovic Courtès <ludo@gnu.org>
;;;
;;; 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 (guix self)
  #:use-module (guix config)
  #:use-module (guix i18n)
  #:use-module (guix modules)
  #:use-module (guix gexp)
  #:use-module (guix store)
  #:use-module (guix monads)
  #:use-module (guix discovery)
  #:use-module (guix packages)
  #:use-module (guix sets)
  #:use-module (guix modules)
  #:use-module ((guix build utils) #:select (find-files))
  #:use-module ((guix build compile) #:select (%lightweight-optimizations))
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-9)
  #:use-module (srfi srfi-35)
  #:use-module (ice-9 match)
  #:export (make-config.scm
            whole-package                     ;for internal use in 'guix pull'
            compiled-guix
            guix-derivation
            reload-guix))

\f
;;;
;;; Dependency handling.
;;;

(define specification->package
  ;; Use our own variant of that procedure because that of (gnu packages)
  ;; would traverse all the .scm files, which is wasteful.
  (let ((ref (lambda (module variable)
               (module-ref (resolve-interface module) variable))))
    (match-lambda
      ("guile"      (ref '(gnu packages commencement) 'guile-final))
      ("guile-json" (ref '(gnu packages guile) 'guile-json))
      ("guile-ssh"  (ref '(gnu packages ssh)   'guile-ssh))
      ("guile-git"  (ref '(gnu packages guile) 'guile-git))
      ("guile-sqlite3" (ref '(gnu packages guile) 'guile-sqlite3))
      ("guile-gcrypt"  (ref '(gnu packages gnupg) 'guile-gcrypt))
      ("gnutls"     (ref '(gnu packages tls) 'gnutls))
      ("zlib"       (ref '(gnu packages compression) 'zlib))
      ("gzip"       (ref '(gnu packages compression) 'gzip))
      ("bzip2"      (ref '(gnu packages compression) 'bzip2))
      ("xz"         (ref '(gnu packages compression) 'xz))
      (_            #f))))                        ;no such package

\f
;;;
;;; Derivations.
;;;

;; Node in a DAG of build tasks.  Each node maps to a derivation, but it's
;; easier to express things this way.
(define-record-type <node>
  (node name modules source dependencies compiled)
  node?
  (name          node-name)                       ;string
  (modules       node-modules)                    ;list of module names
  (source        node-source)                     ;list of source files
  (dependencies  node-dependencies)               ;list of nodes
  (compiled      node-compiled))                  ;node -> lowerable object

;; File mappings are essentially an alist as passed to 'imported-files'.
(define-record-type <file-mapping>
  (file-mapping name alist)
  file-mapping?
  (name  file-mapping-name)
  (alist file-mapping-alist))

(define-gexp-compiler (file-mapping-compiler (mapping <file-mapping>)
                                             system target)
  ;; Here we use 'imported-files', which can arrange to directly import all
  ;; the files instead of creating a derivation, when possible.
  (imported-files (map (match-lambda
                         ((destination (? local-file? file))
                          (cons destination
                                (local-file-absolute-file-name file)))
                         ((destination source)
                          (cons destination source))) ;silliness
                       (file-mapping-alist mapping))
                  #:name (file-mapping-name mapping)
                  #:system system))

(define (node-source+compiled node)
  "Return a \"bundle\" containing both the source code and object files for
NODE's modules, under their FHS directories: share/guile/site and lib/guile."
  (define build
    (with-imported-modules '((guix build utils))
      #~(begin
          (use-modules (guix build utils))

          (define source
            (string-append #$output "/share/guile/site/"
                           (effective-version)))

          (define object
            (string-append #$output "/lib/guile/" (effective-version)
                           "/site-ccache"))

          (mkdir-p (dirname source))
          (symlink #$(node-source node) source)
          (mkdir-p (dirname object))
          (symlink #$(node-compiled node) object))))

  (computed-file (string-append (node-name node) "-modules")
                 build))

(define (node-fold proc init nodes)
  (let loop ((nodes nodes)
             (visited (setq))
             (result init))
    (match nodes
      (() result)
      ((head tail ...)
       (if (set-contains? visited head)
           (loop tail visited result)
           (loop tail (set-insert head visited)
                 (proc head result)))))))

(define (node-modules/recursive nodes)
  (node-fold (lambda (node modules)
               (append (node-modules node) modules))
             '()
             nodes))

(define* (closure modules #:optional (except '()))
  (source-module-closure modules
                         #:select?
                         (match-lambda
                           (('guix 'config)
                            #f)
                           ((and module
                                 (or ('guix _ ...) ('gnu _ ...)))
                            (not (member module except)))
                           (rest #f))))

(define module->import
  ;; Return a file-name/file-like object pair for the specified module and
  ;; suitable for 'imported-files'.
  (match-lambda
    ((module '=> thing)
     (let ((file (module-name->file-name module)))
       (list file thing)))
    (module
        (let ((file (module-name->file-name module)))
          (list file
                (local-file (search-path %load-path file)))))))

(define* (scheme-node name modules #:optional (dependencies '())
                      #:key (extra-modules '()) (extra-files '())
                      (extensions '())
                      parallel? guile-for-build)
  "Return a node that builds the given Scheme MODULES, and depends on
DEPENDENCIES (a list of nodes).  EXTRA-MODULES is a list of additional modules
added to the source, and EXTRA-FILES is a list of additional files.
EXTENSIONS is a set of full-blown Guile packages (e.g., 'guile-json') that
must be present in the search path."
  (let* ((modules (append extra-modules
                          (closure modules
                                   (node-modules/recursive dependencies))))
         (module-files (map module->import modules))
         (source (file-mapping (string-append name "-source")
                               (append module-files extra-files))))
    (node name modules source dependencies
          (compiled-modules name source
                            (map car module-files)
                            (map node-source dependencies)
                            (map node-compiled dependencies)
                            #:extensions extensions
                            #:parallel? parallel?
                            #:guile-for-build guile-for-build))))

(define (file-imports directory sub-directory pred)
  "List all the files matching PRED under DIRECTORY/SUB-DIRECTORY.  Return a
list of file-name/file-like objects suitable as inputs to 'imported-files'."
  (map (lambda (file)
         (list (string-drop file (+ 1 (string-length directory)))
               (local-file file #:recursive? #t)))
       (find-files (string-append directory "/" sub-directory) pred)))

(define* (file-append* item file #:key (recursive? #t))
  "Return FILE within ITEM, which may be a file name or a file-like object.
When ITEM is a plain file name (a string), simply return a 'local-file'
record with the new file name."
  (match item
    ((? string?)
     ;; This is the optimal case: we return a new "source".  Thus, a
     ;; derivation that depends on this sub-directory does not depend on ITEM
     ;; itself.
     (local-file (string-append item "/" file)
                 #:recursive? recursive?))
    ;; TODO: Add 'local-file?' case.
    (_
     ;; In this case, anything that refers to the result also depends on ITEM,
     ;; which isn't great.
     (file-append item "/" file))))

(define* (locale-data source domain
                      #:optional (directory domain))
  "Return the locale data from 'po/DIRECTORY' in SOURCE, corresponding to
DOMAIN, a gettext domain."
  (define gettext
    (module-ref (resolve-interface '(gnu packages gettext))
                'gettext-minimal))

  (define build
    (with-imported-modules '((guix build utils))
      #~(begin
          (use-modules (guix build utils)
                       (srfi srfi-26)
                       (ice-9 match) (ice-9 ftw))

          (define po-directory
            #+(file-append* source (string-append "po/" directory)))

          (define (compile language)
            (let ((gmo (string-append #$output "/" language "/LC_MESSAGES/"
                                      #$domain ".mo")))
              (mkdir-p (dirname gmo))
              (invoke #+(file-append gettext "/bin/msgfmt")
                      "-c" "--statistics" "--verbose"
                      "-o" gmo
                      (string-append po-directory "/" language ".po"))))

          (define (linguas)
            ;; Return the list of languages.  Note: don't read 'LINGUAS'
            ;; because it contains things like 'en@boldquot' that do not have
            ;; a corresponding .po file.
            (map (cut basename <> ".po")
                 (scandir po-directory
                          (cut string-suffix? ".po" <>))))

          (for-each compile (linguas)))))

  (computed-file (string-append "guix-locale-" domain)
                 build))

(define (info-manual source)
  "Return the Info manual built from SOURCE."
  (define texinfo
    (module-ref (resolve-interface '(gnu packages texinfo))
                'texinfo))

  (define graphviz
    (module-ref (resolve-interface '(gnu packages graphviz))
                'graphviz))

  (define glibc-utf8-locales
    (module-ref (resolve-interface '(gnu packages base))
                'glibc-utf8-locales))

  (define documentation
    (file-append* source "doc"))

  (define examples
    (file-append* source "gnu/system/examples"))

  (define build
    (with-imported-modules '((guix build utils))
      #~(begin
          (use-modules (guix build utils))

          (mkdir #$output)

          ;; Create 'version.texi'.
          ;; XXX: Can we use a more meaningful version string yet one that
          ;; doesn't change at each commit?
          (call-with-output-file "version.texi"
            (lambda (port)
              (let ((version "0.0-git"))
                (format port "
@set UPDATED 1 January 1970
@set UPDATED-MONTH January 1970
@set EDITION ~a
@set VERSION ~a\n" version version))))

          ;; Copy configuration templates that the manual includes.
          (for-each (lambda (template)
                      (copy-file template
                                 (string-append
                                  "os-config-"
                                  (basename template ".tmpl")
                                  ".texi")))
                    (find-files #$examples "\\.tmpl$"))

          ;; Build graphs.
          (mkdir-p (string-append #$output "/images"))
          (for-each (lambda (dot-file)
                      (invoke #+(file-append graphviz "/bin/dot")
                              "-Tpng" "-Gratio=.9" "-Gnodesep=.005"
                              "-Granksep=.00005" "-Nfontsize=9"
                              "-Nheight=.1" "-Nwidth=.1"
                              "-o" (string-append #$output "/images/"
                                                  (basename dot-file ".dot")
                                                  ".png")
                              dot-file))
                    (find-files (string-append #$documentation "/images")
                                "\\.dot$"))

          ;; Copy other PNGs.
          (for-each (lambda (png-file)
                      (install-file png-file
                                    (string-append #$output "/images")))
                    (find-files (string-append #$documentation "/images")
                                "\\.png$"))

          ;; Finally build the manual.  Copy it the Texinfo files to $PWD and
          ;; add a symlink to the 'images' directory so that 'makeinfo' can
          ;; see those images and produce image references in the Info output.
          (copy-recursively #$documentation "."
                            #:log (%make-void-port "w"))
          (delete-file-recursively "images")
          (symlink (string-append #$output "/images") "images")

          ;; Provide UTF-8 locales needed by the 'xspara.c' code in makeinfo.
          (setenv "GUIX_LOCPATH"
                  #+(file-append glibc-utf8-locales "/lib/locale"))

          (for-each (lambda (texi)
                      (unless (string=? "guix.texi" texi)
                        ;; Create 'version-LL.texi'.
                        (let* ((base (basename texi ".texi"))
                               (dot  (string-index base #\.))
                               (tag  (string-drop base (+ 1 dot))))
                          (symlink "version.texi"
                                   (string-append "version-" tag ".texi"))))

                      (invoke #+(file-append texinfo "/bin/makeinfo")
                              texi "-I" #$documentation
                              "-I" "."
                              "-o" (string-append #$output "/"
                                                  (basename texi ".texi")
                                                  ".info")))
                    (cons "guix.texi"
                          (find-files "." "^guix\\.[a-z]{2}\\.texi$")))

          ;; Compress Info files.
          (setenv "PATH"
                  #+(file-append (specification->package "gzip") "/bin"))
          (for-each (lambda (file)
                      (invoke "gzip" "-9n" file))
                    (find-files #$output "\\.info(-[0-9]+)?$")))))

  (computed-file "guix-manual" build))

(define* (guile-module-union things #:key (name "guix-module-union"))
  "Return the union of the subset of THINGS (packages, computed files, etc.)
that provide Guile modules."
  (define build
    (with-imported-modules '((guix build union))
      #~(begin
          (use-modules (guix build union))

          (define (modules directory)
            (string-append directory "/share/guile/site"))

          (define (objects directory)
            (string-append directory "/lib/guile"))

          (union-build #$output
                       (filter (lambda (directory)
                                 (or (file-exists? (modules directory))
                                     (file-exists? (objects directory))))
                               '#$things)

                       #:log-port (%make-void-port "w")))))

  (computed-file name build))

(define* (guix-command modules
                       #:key source (dependencies '())
                       guile (guile-version (effective-version)))
  "Return the 'guix' command such that it adds MODULES and DEPENDENCIES in its
load path."
  (define module-directory
    ;; To minimize the number of 'stat' calls needed to locate a module,
    ;; create the union of all the module directories.
    (guile-module-union (cons modules dependencies)))

  (program-file "guix-command"
                #~(begin
                    (set! %load-path
                      (cons (string-append #$module-directory
                                           "/share/guile/site/"
                                           (effective-version))
                            %load-path))

                    (set! %load-compiled-path
                      (cons (string-append #$module-directory
                                           "/lib/guile/"
                                           (effective-version)
                                           "/site-ccache")
                            %load-compiled-path))

                    (let ((guix-main (module-ref (resolve-interface '(guix ui))
                                                 'guix-main)))
                      #$(if source
                            #~(begin
                                (bindtextdomain "guix"
                                                #$(locale-data source "guix"))
                                (bindtextdomain "guix-packages"
                                                #$(locale-data source
                                                               "guix-packages"
                                                               "packages")))
                            #t)

                      ;; XXX: It would be more convenient to change it to:
                      ;;   (exit (apply guix-main (command-line)))
                      (apply guix-main (command-line))))
                #:guile guile))

(define (miscellaneous-files source)
  "Return data files taken from SOURCE."
  (file-mapping "guix-misc"
                `(("etc/bash_completion.d/guix"
                   ,(file-append* source "/etc/completion/bash/guix"))
                  ("etc/bash_completion.d/guix-daemon"
                   ,(file-append* source "/etc/completion/bash/guix-daemon"))
                  ("share/zsh/site-functions/_guix"
                   ,(file-append* source "/etc/completion/zsh/_guix"))
                  ("share/fish/vendor_completions.d/guix.fish"
                   ,(file-append* source "/etc/completion/fish/guix.fish"))
                  ("share/guix/hydra.gnu.org.pub"
                   ,(file-append* source
                                  "/etc/substitutes/hydra.gnu.org.pub"))
                  ("share/guix/berlin.guixsd.org.pub"
                   ,(file-append* source
                                  "/etc/substitutes/berlin.guixsd.org.pub"))
                  ("share/guix/ci.guix.info.pub"  ;alias
                   ,(file-append* source "/etc/substitutes/berlin.guixsd.org.pub")))))

(define* (whole-package name modules dependencies
                        #:key
                        (guile-version (effective-version))
                        info daemon miscellany
                        guile
                        (command (guix-command modules
                                               #:dependencies dependencies
                                               #:guile guile
                                               #:guile-version guile-version)))
  "Return the whole Guix package NAME that uses MODULES, a derivation of all
the modules (under share/guile/site and lib/guile), and DEPENDENCIES, a list
of packages depended on.  COMMAND is the 'guix' program to use; INFO is the
Info manual."
  (computed-file name
                 (with-imported-modules '((guix build utils))
                   #~(begin
                       (use-modules (guix build utils))

                       (mkdir-p (string-append #$output "/bin"))
                       (symlink #$command
                                (string-append #$output "/bin/guix"))

                       (when #$daemon
                         (symlink (string-append #$daemon "/bin/guix-daemon")
                                  (string-append #$output "/bin/guix-daemon")))

                       (let ((share (string-append #$output "/share"))
                             (lib   (string-append #$output "/lib"))
                             (info  #$info))
                         (mkdir-p share)
                         (symlink #$(file-append modules "/share/guile")
                                  (string-append share "/guile"))
                         (when info
                           (symlink #$info (string-append share "/info")))

                         (mkdir-p lib)
                         (symlink #$(file-append modules "/lib/guile")
                                  (string-append lib "/guile")))

                       (when #$miscellany
                         (copy-recursively #$miscellany #$output
                                           #:log (%make-void-port "w")))))))

(define* (compiled-guix source #:key (version %guix-version)
                        (pull-version 1)
                        (name (string-append "guix-" version))
                        (guile-version (effective-version))
                        (guile-for-build (default-guile))
                        (zlib (specification->package "zlib"))
                        (gzip (specification->package "gzip"))
                        (bzip2 (specification->package "bzip2"))
                        (xz (specification->package "xz"))
                        (guix (specification->package "guix")))
  "Return a file-like object that contains a compiled Guix."
  (define guile-json
    (specification->package "guile-json"))

  (define guile-ssh
    (specification->package "guile-ssh"))

  (define guile-git
    (specification->package "guile-git"))

  (define guile-sqlite3
    (specification->package "guile-sqlite3"))

  (define guile-gcrypt
    (specification->package "guile-gcrypt"))

  (define gnutls
    (specification->package "gnutls"))

  (define dependencies
    (match (append-map (lambda (package)
                         (cons (list "x" package)
                               (package-transitive-propagated-inputs package)))
                       (list guile-gcrypt gnutls guile-git guile-json
                             guile-ssh guile-sqlite3))
      (((labels packages _ ...) ...)
       packages)))

  (define *core-modules*
    (scheme-node "guix-core"
                 '((guix)
                   (guix monad-repl)
                   (guix packages)
                   (guix download)
                   (guix discovery)
                   (guix profiles)
                   (guix build-system gnu)
                   (guix build-system trivial)
                   (guix build profiles)
                   (guix build gnu-build-system))

                 ;; Provide a dummy (guix config) with the default version
                 ;; number, storedir, etc.  This is so that "guix-core" is the
                 ;; same across all installations and doesn't need to be
                 ;; rebuilt when the version changes, which in turn means we
                 ;; can have substitutes for it.
                 #:extra-modules
                 `(((guix config) => ,(make-config.scm)))

                 ;; (guix man-db) is needed at build-time by (guix profiles)
                 ;; but we don't need to compile it; not compiling it allows
                 ;; us to avoid an extra dependency on guile-gdbm-ffi.
                 #:extra-files
                 `(("guix/man-db.scm" ,(local-file "../guix/man-db.scm"))
                   ("guix/store/schema.sql"
                    ,(local-file "../guix/store/schema.sql")))

                 #:extensions (list guile-gcrypt)
                 #:guile-for-build guile-for-build))

  (define *extra-modules*
    (scheme-node "guix-extra"
                 (filter-map (match-lambda
                               (('guix 'scripts _ ..1) #f)
                               (('guix 'man-db) #f)
                               (name name))
                             (scheme-modules* source "guix"))
                 (list *core-modules*)
                 #:extensions dependencies
                 #:guile-for-build guile-for-build))

  (define *core-package-modules*
    (scheme-node "guix-packages-base"
                 `((gnu packages)
                   (gnu packages base))
                 (list *core-modules* *extra-modules*)
                 #:extensions dependencies

                 ;; Add all the non-Scheme files here.  We must do it here so
                 ;; that 'search-patches' & co. can find them.  Ideally we'd
                 ;; keep them next to the .scm files that use them but it's
                 ;; difficult to do (XXX).
                 #:extra-files
                 (file-imports source "gnu/packages"
                               (lambda (file stat)
                                 (and (eq? 'regular (stat:type stat))
                                      (not (string-suffix? ".scm" file))
                                      (not (string-suffix? ".go" file))
                                      (not (string-prefix? ".#" file))
                                      (not (string-suffix? "~" file)))))
                 #:guile-for-build guile-for-build))

  (define *package-modules*
    (scheme-node "guix-packages"
                 (scheme-modules* source "gnu/packages")
                 (list *core-modules* *extra-modules* *core-package-modules*)
                 #:extensions dependencies
                 #:guile-for-build guile-for-build))

  (define *system-modules*
    (scheme-node "guix-system"
                 `((gnu system)
                   (gnu services)
                   ,@(scheme-modules* source "gnu/system")
                   ,@(scheme-modules* source "gnu/services"))
                 (list *core-package-modules* *package-modules*
                       *extra-modules* *core-modules*)
                 #:extensions dependencies
                 #:extra-files
                 (append (file-imports source "gnu/system/examples"
                                       (const #t))

                         ;; Need so we get access system tests from an
                         ;; inferior.
                         (file-imports source "gnu/tests" (const #t))

                         ;; All the installer code is on the build-side.
                         (file-imports source "gnu/installer/"
                                       (const #t))
                         ;; Build-side code that we don't build.  Some of
                         ;; these depend on guile-rsvg, the Shepherd, etc.
                         (file-imports source "gnu/build" (const #t)))
                 #:guile-for-build
                 guile-for-build))

  (define *cli-modules*
    (scheme-node "guix-cli"
                 (append (scheme-modules* source "/guix/scripts")
                         `((gnu ci)))
                 (list *core-modules* *extra-modules*
                       *core-package-modules* *package-modules*
                       *system-modules*)
                 #:extensions dependencies
                 #:guile-for-build guile-for-build))

  (define *config*
    (scheme-node "guix-config"
                 '()
                 #:extra-modules
                 `(((guix config)
                    => ,(make-config.scm #:zlib zlib
                                         #:gzip gzip
                                         #:bzip2 bzip2
                                         #:xz xz
                                         #:package-name
                                         %guix-package-name
                                         #:package-version
                                         version
                                         #:bug-report-address
                                         %guix-bug-report-address
                                         #:home-page-url
                                         %guix-home-page-url)))
                 #:guile-for-build guile-for-build))

  (define (built-modules node-subset)
    (directory-union (string-append name "-modules")
                     (append-map node-subset

                                 ;; Note: *CONFIG* comes first so that it
                                 ;; overrides the (guix config) module that
                                 ;; comes with *CORE-MODULES*.
                                 (list *config*
                                       *cli-modules*
                                       *system-modules*
                                       *package-modules*
                                       *core-package-modules*
                                       *extra-modules*
                                       *core-modules*))

                     ;; Silently choose the first entry upon collision so that
                     ;; we choose *CONFIG*.
                     #:resolve-collision 'first

                     ;; When we do (add-to-store "utils.scm"), "utils.scm" must
                     ;; be a regular file, not a symlink.  Thus, arrange so that
                     ;; regular files appear as regular files in the final
                     ;; output.
                     #:copy? #t
                     #:quiet? #t))

  ;; Version 0 of 'guix pull' meant we'd just return Scheme modules.
  ;; Version 1 is when we return the full package.
  (cond ((= 1 pull-version)
         ;; The whole package, with a standard file hierarchy.
         (let* ((modules  (built-modules (compose list node-source+compiled)))
                (command  (guix-command modules
                                        #:source source
                                        #:dependencies dependencies
                                        #:guile guile-for-build
                                        #:guile-version guile-version)))
           (whole-package name modules dependencies
                          #:command command
                          #:guile guile-for-build

                          ;; Include 'guix-daemon'.  XXX: Here we inject an
                          ;; older snapshot of guix-daemon, but that's a good
                          ;; enough approximation for now.
                          #:daemon (module-ref (resolve-interface
                                                '(gnu packages
                                                      package-management))
                                               'guix-daemon)

                          #:info (info-manual source)
                          #:miscellany (miscellaneous-files source)
                          #:guile-version guile-version)))
        ((= 0 pull-version)
         ;; Legacy 'guix pull': return the .scm and .go files as one
         ;; directory.
         (built-modules (lambda (node)
                          (list (node-source node)
                                (node-compiled node)))))
        (else
         ;; Unsupported 'guix pull' version.
         #f)))

\f
;;;
;;; Generating (guix config).
;;;

(define %dependency-variables
  ;; (guix config) variables corresponding to dependencies.
  '(%libz %xz %gzip %bzip2))

(define %persona-variables
  ;; (guix config) variables that define Guix's persona.
  '(%guix-package-name
    %guix-version
    %guix-bug-report-address
    %guix-home-page-url))

(define %config-variables
  ;; (guix config) variables corresponding to Guix configuration.
  (letrec-syntax ((variables (syntax-rules ()
                               ((_)
                                '())
                               ((_ variable rest ...)
                                (cons `(variable . ,variable)
                                      (variables rest ...))))))
    (variables %localstatedir %storedir %sysconfdir %system)))

(define* (make-config.scm #:key zlib gzip xz bzip2
                          (package-name "GNU Guix")
                          (package-version "0")
                          (bug-report-address "bug-guix@gnu.org")
                          (home-page-url "https://gnu.org/s/guix"))

  ;; Hack so that Geiser is not confused.
  (define defmod 'define-module)

  (scheme-file "config.scm"
               #~(;; The following expressions get spliced.
                   (#$defmod (guix config)
                     #:export (%guix-package-name
                               %guix-version
                               %guix-bug-report-address
                               %guix-home-page-url
                               %store-directory
                               %state-directory
                               %store-database-directory
                               %config-directory
                               %libz
                               %gzip
                               %bzip2
                               %xz))

                   #$@(map (match-lambda
                             ((name . value)
                              #~(define-public #$name #$value)))
                           %config-variables)

                   (define %store-directory
                     (or (and=> (getenv "NIX_STORE_DIR") canonicalize-path)
                         %storedir))

                   (define %state-directory
                     ;; This must match `NIX_STATE_DIR' as defined in
                     ;; `nix/local.mk'.
                     (or (getenv "NIX_STATE_DIR")
                         (string-append %localstatedir "/guix")))

                   (define %store-database-directory
                     (or (getenv "NIX_DB_DIR")
                         (string-append %state-directory "/db")))

                   (define %config-directory
                     ;; This must match `GUIX_CONFIGURATION_DIRECTORY' as
                     ;; defined in `nix/local.mk'.
                     (or (getenv "GUIX_CONFIGURATION_DIRECTORY")
                         (string-append %sysconfdir "/guix")))

                   (define %guix-package-name #$package-name)
                   (define %guix-version #$package-version)
                   (define %guix-bug-report-address #$bug-report-address)
                   (define %guix-home-page-url #$home-page-url)

                   (define %gzip
                     #+(and gzip (file-append gzip "/bin/gzip")))
                   (define %bzip2
                     #+(and bzip2 (file-append bzip2 "/bin/bzip2")))
                   (define %xz
                     #+(and xz (file-append xz "/bin/xz")))

                   (define %libz
                     #+(and zlib
                            (file-append zlib "/lib/libz"))))

               ;; Guile 2.0 *requires* the 'define-module' to be at the
               ;; top-level or the 'toplevel-ref' in the resulting .go file are
               ;; made relative to a nonexistent anonymous module.
               #:splice? #t))

\f
;;;
;;; Building.
;;;

(define* (compiled-modules name module-tree module-files
                           #:optional
                           (dependencies '())
                           (dependencies-compiled '())
                           #:key
                           (extensions '())       ;full-blown Guile packages
                           parallel?
                           guile-for-build)
  "Build all the MODULE-FILES from MODULE-TREE.  MODULE-FILES must be a list
like '(\"guix/foo.scm\" \"gnu/bar.scm\") and MODULE-TREE is the directory
containing MODULE-FILES and possibly other files as well."
  ;; This is a non-monadic, enhanced version of 'compiled-file' from (guix
  ;; gexp).
  (define build
    (with-imported-modules (source-module-closure
                            '((guix build compile)
                              (guix build utils)))
      #~(begin
          (use-modules (srfi srfi-26)
                       (ice-9 match)
                       (ice-9 format)
                       (ice-9 threads)
                       (guix build compile)
                       (guix build utils))

          (define (regular? file)
            (not (member file '("." ".."))))

          (define (report-load file total completed)
            (display #\cr)
            (format #t
                    "loading...\t~5,1f% of ~d files" ;FIXME: i18n
                    (* 100. (/ completed total)) total)
            (force-output))

          (define (report-compilation file total completed)
            (display #\cr)
            (format #t "compiling...\t~5,1f% of ~d files" ;FIXME: i18n
                    (* 100. (/ completed total)) total)
            (force-output))

          (define (process-directory directory files output)
            ;; Hide compilation warnings.
            (parameterize ((current-warning-port (%make-void-port "w")))
              (compile-files directory #$output files
                             #:workers (parallel-job-count)
                             #:report-load report-load
                             #:report-compilation report-compilation)))

          (setvbuf (current-output-port) 'none)
          (setvbuf (current-error-port) 'none)

          (set! %load-path (cons #+module-tree %load-path))
          (set! %load-path
            (append '#+dependencies
                    (map (lambda (extension)
                           (string-append extension "/share/guile/site/"
                                          (effective-version)))
                         '#+extensions)
                    %load-path))

          (set! %load-compiled-path
            (append '#+dependencies-compiled
                    (map (lambda (extension)
                           (string-append extension "/lib/guile/"
                                          (effective-version)
                                          "/site-ccache"))
                         '#+extensions)
                    %load-compiled-path))

          ;; Load the compiler modules upfront.
          (compile #f)

          (mkdir #$output)
          (chdir #+module-tree)
          (process-directory "." '#+module-files #$output)
          (newline))))

  (computed-file name build
                 #:guile guile-for-build
                 #:options
                 `(#:local-build? #f              ;allow substitutes

                   ;; Don't annoy people about _IONBF deprecation.
                   ;; Initialize 'terminal-width' in (system repl debug)
                   ;; to a large-enough value to make backtrace more
                   ;; verbose.
                   #:env-vars (("GUILE_WARN_DEPRECATED" . "no")
                               ("COLUMNS" . "200")))))

\f
;;;
;;; Building.
;;;

(define* (guix-derivation source version
                          #:optional (guile-version (effective-version))
                          #:key (pull-version 0))
  "Return, as a monadic value, the derivation to build the Guix from SOURCE
for GUILE-VERSION.  Use VERSION as the version string.  PULL-VERSION specifies
the version of the 'guix pull' protocol.  Return #f if this PULL-VERSION value
is not supported."
  (define (shorten version)
    (if (and (string-every char-set:hex-digit version)
             (> (string-length version) 9))
        (string-take version 9)                   ;Git commit
        version))

  (define guile
    ;; When PULL-VERSION >= 1, produce a self-contained Guix and use Guile 2.2
    ;; unconditionally.
    (default-guile))

  (when (and (< pull-version 1)
             (not (string=? (package-version guile) guile-version)))
    ;; Guix < 0.15.0 has PULL-VERSION = 0, where the host Guile is reused and
    ;; can be any version.  When that happens and Guile is not current (e.g.,
    ;; it's Guile 2.0), just bail out.
    (raise (condition
            (&message
             (message "Guix is too old and cannot be upgraded")))))

  (mbegin %store-monad
    (set-guile-for-build guile)
    (let ((guix (compiled-guix source
                               #:version version
                               #:name (string-append "guix-"
                                                     (shorten version))
                               #:pull-version pull-version
                               #:guile-version (if (>= pull-version 1)
                                                   "2.2" guile-version)
                               #:guile-for-build guile)))
      (if guix
          (lower-object guix)
          (return #f)))))