make/gmk-default.scm
2016-02-28 12:55:20 -05:00

53 lines
1.7 KiB
Scheme

;; Contents of the (gnu make) Guile module
;; Copyright (C) 2011-2016 Free Software Foundation, Inc.
;; This file is part of GNU Make.
;;
;; GNU Make 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 Make 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 this program. If not, see <http://www.gnu.org/licenses/>.
(define (to-string-maybe x)
(cond
;; In GNU make, "false" is the empty string
((or (not x)
(unspecified? x)
(variable? x)
(null? x)
(and (string? x) (string-null? x)))
#f)
;; We want something not false... not sure about this
((eq? x #t) "#t")
;; Basics
((or (symbol? x) (number? x))
(object->string x))
((char? x)
(string x))
;; Printable string (no special characters)
((and (string? x) (string-every char-set:printing x))
x)
;; No idea: fail
(else (error "Unknown object:" x))))
(define (obj-to-str x)
(let ((acc '()))
(define (walk x)
(cond ((pair? x) (walk (car x)) (walk (cdr x)))
((to-string-maybe x) => (lambda (s) (set! acc (cons s acc))))))
(walk x)
(string-join (reverse! acc))))
;; Return the value of the GNU make variable V
(define (gmk-var v)
(gmk-expand (format #f "$(~a)" (obj-to-str v))))
;; Export the public interfaces
(export gmk-expand gmk-eval gmk-var)