;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2018-2021, 2024 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 describe)
#:use-module (guix memoization)
#:use-module (guix profiles)
#:use-module (guix packages)
#:use-module ((guix utils) #:select (location-file))
#:use-module ((guix store) #:select (%store-prefix store-path?))
#:use-module ((guix config) #:select (%state-directory))
#:autoload (guix channels) (channel-name
sexp->channel
manifest-entry-channel)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-34)
#:use-module (ice-9 match)
#:export (current-profile
current-profile-date
current-profile-entries
current-channels
package-path-entries
package-provenance
package-channels
manifest-entry-with-provenance
manifest-entry-provenance))
;;; Commentary:
;;;
;;; This module provides supporting code to allow a Guix instance to find, at
;;; run time, which profile it's in (profiles created by 'guix pull'). That
;;; allows it to read meta-information about itself (e.g., repository URL and
;;; commit ID) and to find other channels available in the same profile. It's
;;; a bit like ELPA's pkg-info.el.
;;;
;;; Code:
(define initial-program-arguments
;; Save the initial program arguments. This allows us to see the "real"
;; 'guix' program, even if 'guix repl -s' calls 'set-program-arguments'
;; later on.
(program-arguments))
(define (find-profile program)
"Return the profile created by 'guix pull' or 'guix time-machine' that
PROGRAM lives in; PROGRAM is expected to end in \"/bin/guix\". Return #f if
such a profile could not be found."
(and (string-suffix? "/bin/guix" program)
;; Note: We want to do _lexical dot-dot resolution_. Using ".." for
;; real would instead take us into the /gnu/store directory that
;; ~/.config/guix/current/bin points to, whereas we want to obtain
;; ~/.config/guix/current.
(let ((candidate (dirname (dirname program))))
(and (file-exists? (string-append candidate "/manifest"))
(let ((manifest (guard (c ((profile-error? c) #f))
(profile-manifest candidate))))
(define (fallback)
(or (and=> (false-if-exception (readlink program))
find-profile)
(and=> (false-if-exception (readlink (dirname program)))
(lambda (target)
(find-profile (in-vicinity target "guix"))))))
;; Is CANDIDATE the "right" profile--the one created by 'guix
;; pull'? It might be that CANDIDATE itself contains a
;; symlink to the "right" profile; this happens for instance
;; when using 'guix shell -CW'. Thus, if CANDIDATE doesn't
;; fit the bill, dereference PROGRAM or its parent directory
;; and try again.
(match (and manifest
(manifest-lookup manifest
(manifest-pattern (name "guix"))))
(#f
(fallback))
(entry
(if (assq 'source (manifest-entry-properties entry))
candidate
(fallback)))))))))
(define current-profile
(mlambda ()
"Return the profile (created by 'guix pull') the calling process lives in,
or #f if this is not applicable."
(match initial-program-arguments
((program . _)
(find-profile program)))))
(define (current-profile-date)
"Return the creation date of the current profile (produced by 'guix pull'),
as a number of seconds since the Epoch, or #f if it could not be determined."
;; Normally 'current-profile' will return ~/.config/guix/current. We need
;; to 'readlink' once to get '/var/guix/…/guix-profile', whose mtime is the
;; piece of information we're looking for.
(let loop ((profile (current-profile)))
(match profile
(#f #f)
((? store-path?) #f)
(file
(if (string-prefix? %state-directory file)
(and=> (lstat file) stat:mtime)
(catch 'system-error
(lambda ()
(let ((target (readlink file)))
(loop (if (string-prefix? "/" target)
target
(string-append (dirname file) "/" target)))))
(const #f)))))))
(define (channel-metadata)
"Return the 'guix' channel metadata sexp from (guix config) if available;
otherwise return #f."
;; Older 'build-self.scm' would create a (guix config) file without the
;; '%channel-metadata' variable. Thus, properly deal with a lack of
;; information.
(let ((module (resolve-interface '(guix config))))
(and=> (module-variable module '%channel-metadata) variable-ref)))
(define current-profile-entries
(mlambda ()
"Return the list of entries in the 'guix pull' profile the calling process
lives in, or the empty list if this is not applicable."
(match (current-profile)
(#f '())
(profile
(let ((manifest (profile-manifest profile)))
(manifest-entries manifest))))))
(define current-channel-entries
(mlambda ()
"Return manifest entries corresponding to extra channels--i.e., not the
'guix' channel."
(remove (lambda (entry)
(or (string=? (manifest-entry-name entry) "guix")
;; If ENTRY lacks the 'source' property, it's not an entry
;; from 'guix pull'. See <https://bugs.gnu.org/48778>.
(not (assq 'source (manifest-entry-properties entry)))))
(current-profile-entries))))
(define current-channels
(mlambda ()
"Return the list of channels currently available, including the 'guix'
channel. Return the empty list if this information is missing."
(define (build-time-metadata)
(match (channel-metadata)
(#f '())
(sexp (or (and=> (sexp->channel sexp 'guix) list) '()))))
(match (current-profile-entries)
(()
;; As a fallback, if we're not running from a profile, use 'guix'
;; channel metadata from (guix config).
(build-time-metadata))
(entries
(match (filter-map manifest-entry-channel entries)
(()
;; This profile lacks provenance metadata, so fall back to
;; build-time metadata as returned by 'channel-metadata'.
(build-time-metadata))
(lst
lst))))))
(define (package-path-entries)
"Return two values: the list of package path entries to be added to the
package search path, and the list to be added to %LOAD-COMPILED-PATH. These
entries are taken from the 'guix pull' profile the calling process lives in,
when applicable."
;; Filter out Guix itself.
(unzip2 (map (lambda (entry)
(list (string-append (manifest-entry-item entry)
"/share/guile/site/"
(effective-version))
(string-append (manifest-entry-item entry)
"/lib/guile/" (effective-version)
"/site-ccache")))
(current-channel-entries))))
(define (package-channels package)
"Return the list of channels providing PACKAGE or an empty list if it could
not be determined."
(match (and=> (package-location package) location-file)
(#f '())
(file
(let ((file (if (string-prefix? "/" file)
file
(search-path %load-path file))))
(if (and file
(string-prefix? (%store-prefix) file))
(filter-map
(lambda (entry)
(let ((item (manifest-entry-item entry)))
(and (or (string-prefix? item file)
(string=? "guix" (manifest-entry-name entry)))
(manifest-entry-channel entry))))
(current-profile-entries))
'())))))
(define (package-provenance package)
"Return the provenance of PACKAGE as an sexp for use as the 'provenance'
property of manifest entries, or #f if it could not be determined."
(define (entry-source entry)
(match (assq 'source
(manifest-entry-properties entry))
(('source value) value)
(_ #f)))
(let* ((channels (package-channels package))
(names (map (compose symbol->string channel-name) channels)))
;; Always store information about the 'guix' channel and
;; optionally about the specific channel FILE comes from.
(or (let ((main (and=> (find (lambda (entry)
(string=? "guix"
(manifest-entry-name entry)))
(current-profile-entries))
entry-source))
(extra (any (lambda (entry)
(let ((item (manifest-entry-item entry))
(name (manifest-entry-name entry)))
(and (member name names)
(not (string=? name "guix"))
(entry-source entry))))
(current-profile-entries))))
(and main
`(,main
,@(if extra (list extra) '())))))))
(define (manifest-entry-with-provenance entry)
"Return ENTRY with an additional 'provenance' property if it's not already
there."
(let ((properties (manifest-entry-properties entry)))
(if (assq 'provenance properties)
entry
(let ((item (manifest-entry-item entry)))
(manifest-entry
(inherit entry)
(properties
(match (and (package? item) (package-provenance item))
(#f properties)
(sexp `((provenance ,@sexp)
,@properties)))))))))
(define (manifest-entry-provenance entry)
"Return the list of channels ENTRY comes from. Return the empty list if
that information is missing."
(match (assq-ref (manifest-entry-properties entry) 'provenance)
((main extras ...)
;; XXX: Until recently, channel sexps lacked the channel name. For
;; entries created by 'manifest-entry-with-provenance', the first sexp
;; is known to be the 'guix channel, and for the other ones, invent a
;; fallback name (it's OK as the name is just a "pet name").
(match (sexp->channel main 'guix)
(#f '())
(channel
(let loop ((extras extras)
(counter 1)
(channels (list channel)))
(match extras
(()
(reverse channels))
((head . tail)
(let* ((name (string->symbol
(format #f "channel~a" counter)))
(extra (sexp->channel head name)))
(if extra
(loop tail (+ 1 counter) (cons extra channels))
(loop tail counter channels)))))))))
(_
'())))
