guix-devel/guix/deprecation.scm

90 lines
3.3 KiB
Scheme

;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 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 deprecation)
#:use-module (guix i18n)
#:use-module (ice-9 format)
#:export (define-deprecated
without-deprecation-warnings
deprecation-warning-port))
;;; Commentary:
;;;
;;; Provide a mechanism to mark bindings as deprecated.
;;;
;;; We don't reuse (guix ui) mostly to avoid pulling in too many things.
;;;
;;; Code:
(define deprecation-warning-port
;; Port where deprecation warnings go.
(make-parameter (current-warning-port)))
(define (source-properties->location-string properties)
"Return a human-friendly, GNU-standard representation of PROPERTIES, a
source property alist."
(let ((file (assq-ref properties 'filename))
(line (assq-ref properties 'line))
(column (assq-ref properties 'column)))
(if (and file line column)
(format #f "~a:~a:~a" file (+ 1 line) column)
(G_ "<unknown location>"))))
(define* (warn-about-deprecation variable properties
#:key replacement)
(format (deprecation-warning-port)
(G_ "~a: warning: '~a' is deprecated~@[, use '~a' instead~]~%")
(source-properties->location-string properties)
variable replacement))
(define-syntax define-deprecated
(lambda (s)
"Define a deprecated variable or procedure, along these lines:
(define-deprecated foo bar 42)
(define-deprecated (baz x y) qux (qux y x))
This will write a deprecation warning to DEPRECATION-WARNING-PORT."
(syntax-case s ()
((_ (proc formals ...) replacement body ...)
#'(define-deprecated proc replacement
(lambda* (formals ...) body ...)))
((_ variable replacement exp)
(identifier? #'variable)
(with-syntax ((real (datum->syntax
#'variable
(symbol-append '%
(syntax->datum #'variable)
'/deprecated))))
#`(begin
(define real
(begin
(lambda () replacement) ;just to ensure it's bound
exp))
(define-syntax variable
(lambda (s)
(warn-about-deprecation 'variable (syntax-source s)
#:replacement 'replacement)
(syntax-case s ()
((_ args (... ...))
#'(real args (... ...)))
(id
(identifier? #'id)
#'real))))))))))