guix-devel/guix/build/utils.scm

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;;; Guix --- Nix package management from Guile. -*- coding: utf-8 -*-
;;; Copyright (C) 2012 Ludovic Courtès <ludo@gnu.org>
;;;
;;; This file is part of Guix.
;;;
;;; 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.
;;;
;;; 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 Guix. If not, see <http://www.gnu.org/licenses/>.
(define-module (guix build utils)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-11)
#:use-module (ice-9 match)
#:use-module (ice-9 regex)
#:use-module (ice-9 rdelim)
#:use-module (rnrs bytevectors)
#:use-module (rnrs io ports)
#:export (directory-exists?
with-directory-excursion
set-path-environment-variable
search-path-as-string->list
list->search-path-as-string
alist-cons-before
alist-cons-after
alist-replace
substitute
substitute*
dump-port
patch-shebang))
;;;
;;; Directories.
;;;
(define (directory-exists? dir)
"Return #t if DIR exists and is a directory."
(let ((s (stat dir #f)))
(and s
(eq? 'directory (stat:type s)))))
(define-syntax-rule (with-directory-excursion dir body ...)
"Run BODY with DIR as the process's current directory."
(let ((init (getcwd)))
(dynamic-wind
(lambda ()
(chdir dir))
(lambda ()
body ...)
(lambda ()
(chdir init)))))
;;;
;;; Search paths.
;;;
(define (search-path-as-list sub-directories input-dirs)
"Return the list of directories among SUB-DIRECTORIES that exist in
INPUT-DIRS. Example:
(search-path-as-list '(\"share/emacs/site-lisp\" \"share/emacs/24.1\")
(list \"/package1\" \"/package2\" \"/package3\"))
=> (\"/package1/share/emacs/site-lisp\"
\"/package3/share/emacs/site-lisp\")
"
(append-map (lambda (input)
(filter-map (lambda (dir)
(let ((dir (string-append input "/"
dir)))
(and (directory-exists? dir)
dir)))
sub-directories))
input-dirs))
(define (list->search-path-as-string lst separator)
(string-join lst separator))
(define* (search-path-as-string->list path #:optional (separator #\:))
(string-tokenize path (char-set-complement (char-set separator))))
(define* (set-path-environment-variable env-var sub-directories input-dirs
#:key (separator ":"))
"Look for each of SUB-DIRECTORIES in INPUT-DIRS. Set ENV-VAR to a
SEPARATOR-separated path accordingly. Example:
(set-path-environment-variable \"PKG_CONFIG\"
'(\"lib/pkgconfig\")
(list package1 package2))
"
(setenv env-var
(list->search-path-as-string (search-path-as-list sub-directories
input-dirs)
separator)))
;;;
;;; Phases.
;;;
;;; In (guix build gnu-build-system), there are separate phases (configure,
;;; build, test, install). They are represented as a list of name/procedure
;;; pairs. The following procedures make it easy to change the list of
;;; phases.
;;;
(define* (alist-cons-before reference key value alist
#:optional (key=? equal?))
"Insert the KEY/VALUE pair before the first occurrence of a pair whose key
is REFERENCE in ALIST. Use KEY=? to compare keys."
(let-values (((before after)
(break (match-lambda
((k . _)
(key=? k reference)))
alist)))
(append before (alist-cons key value after))))
(define* (alist-cons-after reference key value alist
#:optional (key=? equal?))
"Insert the KEY/VALUE pair after the first occurrence of a pair whose key
is REFERENCE in ALIST. Use KEY=? to compare keys."
(let-values (((before after)
(break (match-lambda
((k . _)
(key=? k reference)))
alist)))
(match after
((reference after ...)
(append before (cons* reference `(,key . ,value) after)))
(()
(append before `((,key . ,value)))))))
(define* (alist-replace key value alist #:optional (key=? equal?))
"Replace the first pair in ALIST whose car is KEY with the KEY/VALUE pair.
An error is raised when no such pair exists."
(let-values (((before after)
(break (match-lambda
((k . _)
(key=? k key)))
alist)))
(match after
((_ after ...)
(append before (alist-cons key value after))))))
;;;
;;; Text substitution (aka. sed).
;;;
(define (substitute file pattern+procs)
"PATTERN+PROCS is a list of regexp/two-argument procedure. For each line
of FILE, and for each PATTERN that it matches, call the corresponding PROC
as (PROC MATCH OUTPUT-PORT)."
(let* ((rx+proc (map (match-lambda
(((? regexp? pattern) . proc)
(cons pattern proc))
((pattern . proc)
(cons (make-regexp pattern regexp/extended)
proc)))
pattern+procs))
(template (string-append file ".XXXXXX"))
(out (mkstemp! template))
(mode (stat:mode (stat file))))
(with-throw-handler #t
(lambda ()
(call-with-input-file file
(lambda (in)
(let loop ((line (read-line in)))
(if (eof-object? line)
#t
(begin
(or (any (match-lambda
((regexp . proc)
(and=> (regexp-exec regexp line)
(lambda (m)
(proc m out)
#t))))
rx+proc)
(begin
(display line out)
(newline out)
#t))
(loop (read-line in)))))))
(close out)
(chmod template mode)
(rename-file template file))
(lambda (key . args)
(false-if-exception (delete-file template))))))
(define-syntax let-matches
;; Helper macro for `substitute*'.
(syntax-rules (_)
((let-matches index match (_ vars ...) body ...)
(let-matches (+ 1 index) match (vars ...)
body ...))
((let-matches index match (var vars ...) body ...)
(let ((var (match:substring match index)))
(let-matches (+ 1 index) match (vars ...)
body ...)))
((let-matches index match () body ...)
(begin body ...))))
(define-syntax substitute*
(syntax-rules ()
"Substitute REGEXP in FILE by the string returned by BODY. BODY is
evaluated with each MATCH-VAR bound to the corresponding positional regexp
sub-expression. For example:
(substitute* file
((\"hello\")
\"good morning\\n\")
((\"foo([a-z]+)bar(.*)$\" all letters end)
(string-append \"baz\" letter end)))
Here, anytime a line of FILE contains \"hello\", it is replaced by \"good
morning\". Anytime a line of FILE matches the second regexp, ALL is bound to
the complete match, LETTERS is bound to the first sub-expression, and END is
bound to the last one.
When one of the MATCH-VAR is `_', no variable is bound to the corresponding
match substring."
((substitute* (file ...) clause ...)
(begin
(substitute* file clause ...)
...))
((substitute* file ((regexp match-var ...) body ...) ...)
(substitute file
(list (cons regexp
(lambda (m p)
(let-matches 0 m (match-var ...)
(display (begin body ...) p))))
...)))))
;;;
;;; Patching shebangs---e.g., /bin/sh -> /nix/store/xyz...-bash/bin/sh.
;;;
(define (dump-port in out)
"Read as much data as possible from IN and write it to OUT."
(define buffer-size 4096)
(define buffer
(make-bytevector buffer-size))
(let loop ((bytes (get-bytevector-n! in buffer 0 buffer-size)))
(or (eof-object? bytes)
(begin
(put-bytevector out buffer 0 bytes)
(loop (get-bytevector-n! in buffer 0 buffer-size))))))
(define patch-shebang
(let ((shebang-rx (make-regexp "^[[:blank:]]*([[:graph:]]+)(.*)$")))
(lambda* (file
#:optional (path (search-path-as-string->list (getenv "PATH"))))
"Replace the #! interpreter file name in FILE by a valid one found in
PATH, when FILE actually starts with a shebang. Return #t when FILE was
patched, #f otherwise."
(define (patch p interpreter rest-of-line)
(let* ((template (string-append file ".XXXXXX"))
(out (mkstemp! template))
(mode (stat:mode (stat file))))
(with-throw-handler #t
(lambda ()
(format out "#!~a~a~%"
interpreter rest-of-line)
(dump-port p out)
(close out)
(chmod template mode)
(rename-file template file)
#t)
(lambda (key . args)
(format (current-error-port)
"patch-shebang: ~a: error: ~a ~s~%"
file key args)
(false-if-exception (delete-file template))
#f))))
(with-fluids ((%default-port-encoding #f)) ; ASCII
(call-with-input-file file
(lambda (p)
(and (eq? #\# (read-char p))
(eq? #\! (read-char p))
(let ((line (false-if-exception (read-line p))))
(and=> (and line (regexp-exec shebang-rx line))
(lambda (m)
(let* ((cmd (match:substring m 1))
(bin (search-path path
(basename cmd))))
(if bin
(if (string=? bin cmd)
#f ; nothing to do
(begin
(format (current-error-port)
"patch-shebang: ~a: changing `~a' to `~a'~%"
file cmd bin)
(patch p bin (match:substring m 2))))
(begin
(format (current-error-port)
"patch-shebang: ~a: warning: no binary for interpreter `~a' found in $PATH~%"
file (basename cmd))
#f)))))))))))))
;;; Local Variables:
;;; eval: (put 'call-with-output-file/atomic 'scheme-indent-function 1)
;;; eval: (put 'with-throw-handler 'scheme-indent-function 1)
;;; End: