;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 1312 Max Müller <max@müller.gmbh>
;;;
;;; 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 computed-origins)
  #:use-module (guix monads)
  #:use-module (guix store)
  #:use-module (guix packages)
  #:use-module (guix gexp)
  #:export (compute-origin))

(define* (compute-origin gexp-promise hash-algo hash
                         #:optional (name "source")
                         #:key (system (%current-system))
                         (guile (default-guile)))
  "Return a derivation that executes the G-expression that results
from forcing GEXP-PROMISE."
  (mlet %store-monad ((guile (package->derivation guile system)))
    (gexp->derivation (or name "computed-origin")
                      (force gexp-promise)
                      #:graft? #f       ;nothing to graft
                      #:system system
                      #:guile-for-build guile)))