Add (guix self).

* guix/self.scm: New file.
* Makefile.am (MODULES): Add it.
* gnu/packages.scm (%distro-root-directory): Rewrite to try different
directories.
* guix/discovery.scm (guix): Export 'scheme-files'.

Makefile.am

@@ -81,6 +81,7 @@ MODULES =					\
   guix/derivations.scm				\
   guix/grafts.scm				\
   guix/gnu-maintenance.scm			\
+  guix/self.scm					\
   guix/upstream.scm				\
   guix/licenses.scm				\
   guix/glob.scm					\

gnu/packages.scm

@@ -110,8 +110,25 @@ for system '~a'")
                         file-name system)))))))
 
 (define %distro-root-directory
-  ;; Absolute file name of the module hierarchy.
+  ;; Absolute file name of the module hierarchy.  Since (gnu packages …) might
-  (dirname (search-path %load-path "guix.scm")))
+  ;; live in a directory different from (guix), try to get the best match.
+  (letrec-syntax ((dirname* (syntax-rules ()
+                              ((_ file)
+                               (dirname file))
+                              ((_ file head tail ...)
+                               (dirname (dirname* file tail ...)))))
+                  (try      (syntax-rules ()
+                              ((_ (file things ...) rest ...)
+                               (match (search-path %load-path file)
+                                 (#f
+                                  (try rest ...))
+                                 (absolute
+                                  (dirname* absolute things ...))))
+                              ((_)
+                               #f))))
+    (try ("gnu/packages/base.scm" gnu/ packages/)
+         ("gnu/packages.scm"      gnu/)
+         ("guix.scm"))))
 
 (define %package-module-path
   ;; Search path for package modules.  Each item must be either a directory

guix/discovery.scm

@@ -25,7 +25,8 @@
   #:use-module (ice-9 match)
   #:use-module (ice-9 vlist)
   #:use-module (ice-9 ftw)
-  #:export (scheme-modules
+  #:export (scheme-files
+            scheme-modules
             fold-modules
             all-modules
             fold-module-public-variables))

guix/self.scm

@@ -0,0 +1,599 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2017, 2018 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 utils)
+  #:use-module (guix modules)
+  #:use-module (guix build utils)
+  #:use-module ((guix build compile) #:select (%lightweight-optimizations))
+  #:use-module (srfi srfi-1)
+  #:use-module (srfi srfi-9)
+  #:use-module (ice-9 match)
+  #:export (make-config.scm
+            compiled-guix
+            guix-derivation
+            reload-guix))
+
+
+;;;
+;;; Dependency handling.
+;;;
+
+(define* (false-if-wrong-guile package
+                               #:optional (guile-version (effective-version)))
+  "Return #f if PACKAGE depends on the \"wrong\" major version of Guile (e.g.,
+2.0 instead of 2.2), otherwise return PACKAGE."
+  (let ((guile (any (match-lambda
+                      ((label (? package? dep) _ ...)
+                       (and (string=? (package-name dep) "guile")
+                            dep)))
+                    (package-direct-inputs package))))
+    (and (or (not guile)
+             (string-prefix? guile-version
+                             (package-version guile)))
+         package)))
+
+(define (package-for-guile guile-version . names)
+  "Return the package with one of the given NAMES that depends on
+GUILE-VERSION (\"2.0\" or \"2.2\"), or #f if none of the packages matches."
+  (let loop ((names names))
+    (match names
+      (()
+       #f)
+      ((name rest ...)
+       (match (specification->package name)
+         (#f
+          (loop rest))
+         ((? package? package)
+          (or (false-if-wrong-guile package)
+              (loop rest))))))))
+
+(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))
+      ("libgcrypt"  (ref '(gnu packages gnupg) 'libgcrypt))
+      ("zlib"       (ref '(gnu packages compression) 'zlib))
+      ("gzip"       (ref '(gnu packages compression) 'gzip))
+      ("bzip2"      (ref '(gnu packages compression) 'bzip2))
+      ("xz"         (ref '(gnu packages compression) 'xz))
+      ("guix"       (ref '(gnu packages package-management)
+                         'guix-register)))))
+
+
+;;;
+;;; 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
+
+(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 (imported-files (string-append name "-source")
+                                 (append module-files extra-files))))
+    (node name modules source dependencies
+          (compiled-modules name source modules
+                            (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 (scheme-modules* directory sub-directory)
+  "Return the list of module names found under SUB-DIRECTORY in DIRECTORY."
+  (let ((prefix (string-length directory)))
+    (map (lambda (file)
+           (file-name->module-name (string-drop file prefix)))
+         (scheme-files (string-append directory "/" sub-directory)))))
+
+(define* (compiled-guix source #:key (version %guix-version)
+                        (name (string-append "guix-" version))
+                        (guile-version (effective-version))
+                        (guile-for-build (guile-for-build guile-version))
+                        (libgcrypt (specification->package "libgcrypt"))
+                        (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
+    (package-for-guile guile-version
+                       "guile-json"
+                       "guile2.2-json"
+                       "guile2.0-json"))
+
+  (define guile-ssh
+    (package-for-guile guile-version
+                       "guile-ssh"
+                       "guile2.2-ssh"
+                       "guile2.0-ssh"))
+
+  (define guile-git
+    (package-for-guile guile-version
+                       "guile-git"
+                       "guile2.0-git"))
+
+
+  (define dependencies
+    (match (append-map (lambda (package)
+                         (cons (list "x" package)
+                               (package-transitive-inputs package)))
+                       (list guile-git guile-json guile-ssh))
+      (((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 #:libgcrypt
+                                         (specification->package
+                                          "libgcrypt"))))
+
+                 #:guile-for-build guile-for-build))
+
+  (define *extra-modules*
+    (scheme-node "guix-extra"
+                 (filter-map (match-lambda
+                               (('guix 'scripts _ ..1) #f)
+                               (name name))
+                             (scheme-modules* source "guix"))
+                 (list *core-modules*)
+                 #:extensions dependencies
+                 #:guile-for-build guile-for-build))
+
+  (define *package-modules*
+    (scheme-node "guix-packages"
+                 `((gnu packages)
+                   ,@(scheme-modules* source "gnu/packages"))
+                 (list *core-modules* *extra-modules*)
+                 #:extensions dependencies
+                 #:extra-files                    ;all the non-Scheme 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 *system-modules*
+    (scheme-node "guix-system"
+                 `((gnu system)
+                   (gnu services)
+                   ,@(scheme-modules* source "gnu/system")
+                   ,@(scheme-modules* source "gnu/services"))
+                 (list *package-modules* *extra-modules* *core-modules*)
+                 #:extensions dependencies
+                 #:extra-files
+                 (file-imports source "gnu/system/examples" (const #t))
+                 #:guile-for-build
+                 guile-for-build))
+
+  (define *cli-modules*
+    (scheme-node "guix-cli"
+                 (scheme-modules* source "/guix/scripts")
+                 (list *core-modules* *extra-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 #:libgcrypt libgcrypt
+                                         #:zlib zlib
+                                         #:gzip gzip
+                                         #:bzip2 bzip2
+                                         #:xz xz
+                                         #:guix guix
+                                         #: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))
+
+  (directory-union name
+                   (append-map (lambda (node)
+                                 (list (node-source node)
+                                       (node-compiled node)))
+
+                               ;; 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*
+                                     *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))
+
+
+;;;
+;;; Generating (guix config).
+;;;
+
+(define %dependency-variables
+  ;; (guix config) variables corresponding to dependencies.
+  '(%libgcrypt %libz %xz %gzip %bzip2 %nix-instantiate
+    %sbindir %guix-register-program))
+
+(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 (storedir,
+  ;; localstatedir, etc.)
+  (sort (filter pair?
+                (module-map (lambda (name var)
+                              (and (not (memq name %dependency-variables))
+                                   (not (memq name %persona-variables))
+                                   (cons name (variable-ref var))))
+                            (resolve-interface '(guix config))))
+        (lambda (name+value1 name+value2)
+          (string<? (symbol->string (car name+value1))
+                    (symbol->string (car name+value2))))))
+
+(define* (make-config.scm #:key libgcrypt zlib gzip xz bzip2 guix
+                          (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"
+               #~(begin
+                   (#$defmod (guix config)
+                     #:export (%guix-package-name
+                               %guix-version
+                               %guix-bug-report-address
+                               %guix-home-page-url
+                               %sbindir
+                               %libgcrypt
+                               %libz
+                               %gzip
+                               %bzip2
+                               %xz
+                               %nix-instantiate))
+
+                   ;; XXX: Work around <http://bugs.gnu.org/15602>.
+                   (eval-when (expand load eval)
+                     #$@(map (match-lambda
+                               ((name . value)
+                                #~(define-public #$name #$value)))
+                             %config-variables)
+
+                     (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 %sbindir
+                       ;; This is used to define '%guix-register-program'.
+                       ;; TODO: Use a derivation that builds nothing but the
+                       ;; C++ part.
+                       #+(and guix (file-append guix "/sbin")))
+
+                     (define %guix-register-program
+                       (or (getenv "GUIX_REGISTER")
+                           (and %sbindir
+                                (string-append %sbindir "/guix-register"))))
+
+                     (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 %libgcrypt
+                       #+(and libgcrypt
+                              (file-append libgcrypt "/lib/libgcrypt")))
+                     (define %libz
+                       #+(and zlib
+                              (file-append zlib "/lib/libz")))
+
+                     (define %nix-instantiate     ;for (guix import snix)
+                       "nix-instantiate")))))
+
+
+
+;;;
+;;; Building.
+;;;
+
+(define (imported-files name files)
+  ;; This is a non-monadic, simplified version of 'imported-files' from (guix
+  ;; gexp).
+  (define build
+    (with-imported-modules (source-module-closure
+                            '((guix build utils)))
+      #~(begin
+          (use-modules (ice-9 match)
+                       (guix build utils))
+
+          (mkdir (ungexp output)) (chdir (ungexp output))
+          (for-each (match-lambda
+                      ((final-path store-path)
+                       (mkdir-p (dirname final-path))
+
+                       ;; Note: We need regular files to be regular files, not
+                       ;; symlinks, as this makes a difference for
+                       ;; 'add-to-store'.
+                       (copy-file store-path final-path)))
+                    '#$files))))
+
+  (computed-file name build))
+
+(define* (compiled-modules name module-tree modules
+                           #:optional
+                           (dependencies '())
+                           (dependencies-compiled '())
+                           #:key
+                           (extensions '())       ;full-blown Guile packages
+                           parallel?
+                           guile-for-build)
+  ;; This is a non-monadic, enhanced version of 'compiled-file' from (guix
+  ;; gexp).
+  (define build
+    (with-imported-modules (source-module-closure
+                            '((guix build compile)
+                              (guix build utils)))
+      #~(begin
+          (use-modules (srfi srfi-26)
+                       (ice-9 match)
+                       (ice-9 format)
+                       (ice-9 threads)
+                       (guix build compile)
+                       (guix build utils))
+
+          (define (regular? file)
+            (not (member file '("." ".."))))
+
+          (define (report-load file total completed)
+            (display #\cr)
+            (format #t
+                    "loading...\t~5,1f% of ~d files" ;FIXME: i18n
+                    (* 100. (/ completed total)) total)
+            (force-output))
+
+          (define (report-compilation file total completed)
+            (display #\cr)
+            (format #t "compiling...\t~5,1f% of ~d files" ;FIXME: i18n
+                    (* 100. (/ completed total)) total)
+            (force-output))
+
+          (define (process-directory directory output)
+            (let ((files  (find-files directory "\\.scm$"))
+                  (prefix (+ 1 (string-length directory))))
+              ;; Hide compilation warnings.
+              (parameterize ((current-warning-port (%make-void-port "w")))
+                (compile-files directory #$output
+                               (map (cut string-drop <> prefix) files)
+                               #:workers (parallel-job-count)
+                               #:report-load report-load
+                               #:report-compilation report-compilation))))
+
+          (setvbuf (current-output-port) _IONBF)
+          (setvbuf (current-error-port) _IONBF)
+
+          (set! %load-path (cons #+module-tree %load-path))
+          (set! %load-path
+            (append '#+dependencies
+                    (map (lambda (extension)
+                           (string-append extension "/share/guile/site/"
+                                          (effective-version)))
+                         '#+extensions)
+                    %load-path))
+
+          (set! %load-compiled-path
+            (append '#+dependencies-compiled
+                    (map (lambda (extension)
+                           (string-append extension "/lib/guile/"
+                                          (effective-version)
+                                          "/site-ccache"))
+                         '#+extensions)
+                    %load-compiled-path))
+
+          ;; Load the compiler modules upfront.
+          (compile #f)
+
+          (mkdir #$output)
+          (chdir #+module-tree)
+          (process-directory "." #$output))))
+
+  (computed-file name build
+                 #:guile guile-for-build
+                 #:options
+                 `(#:local-build? #f              ;allow substitutes
+
+                   ;; Don't annoy people about _IONBF deprecation.
+                   #:env-vars (("GUILE_WARN_DEPRECATED" . "no")))))
+
+
+;;;
+;;; Building.
+;;;
+
+(define (guile-for-build version)
+  "Return a derivation for Guile 2.0 or 2.2, whichever matches the currently
+running Guile."
+  (define canonical-package                       ;soft reference
+    (module-ref (resolve-interface '(gnu packages base))
+                'canonical-package))
+
+  (match version
+    ("2.2.2"
+     ;; Gross hack to avoid ABI incompatibilities (see
+     ;; <https://bugs.gnu.org/29570>.)
+     (module-ref (resolve-interface '(gnu packages guile))
+                 'guile-2.2.2))
+    ("2.2"
+     (canonical-package (module-ref (resolve-interface '(gnu packages guile))
+                                    'guile-2.2/fixed)))
+    ("2.0"
+     (canonical-package (specification->package "guile@2.0")))))
+
+(define* (guix-derivation source version
+                          #:optional (guile-version (effective-version)))
+  "Return, as a monadic value, the derivation to build the Guix from SOURCE
+for GUILE-VERSION.  Use VERSION as the version string."
+  (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
+    (guile-for-build guile-version))
+
+  (mbegin %store-monad
+    (set-guile-for-build guile)
+    (lower-object (compiled-guix source
+                                 #:version version
+                                 #:name (string-append "guix-"
+                                                       (shorten version))
+                                 #:guile-version (match guile-version
+                                                   ("2.2.2" "2.2")
+                                                   (version version))
+                                 #:guile-for-build guile))))