guix-play/guix/scripts/style.scm
Ludovic Courtès f23803af20
Add 'guix style'.
* guix/scripts/style.scm, tests/style.scm: New files.
* Makefile.am (MODULES, SCM_TESTS): Add them.
* po/guix/POTFILES.in: Add 'guix/scripts/style.scm'.
* doc/guix.texi (Invoking guix style): New node.
(package Reference): Reference it.
(Invoking guix lint): Likewise.
2021-07-11 00:49:15 +02:00

528 lines
20 KiB
Scheme
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2021 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/>.
;;; Commentary:
;;;
;;; This script updates package definitions so they use the "simplified" style
;;; for input lists, as in:
;;;
;;; (package
;;; ;; ...
;;; (inputs (list foo bar baz)))
;;;
;;; Code:
(define-module (guix scripts style)
#:autoload (gnu packages) (specification->package fold-packages)
#:use-module (guix scripts)
#:use-module ((guix scripts build) #:select (%standard-build-options))
#:use-module (guix combinators)
#:use-module (guix ui)
#:use-module (guix packages)
#:use-module (guix utils)
#:use-module (guix i18n)
#:use-module (guix diagnostics)
#:use-module (ice-9 control)
#:use-module (ice-9 match)
#:use-module (ice-9 rdelim)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-9)
#:use-module (srfi srfi-26)
#:use-module (srfi srfi-37)
#:export (guix-style))
;;;
;;; Comment-preserving reader.
;;;
;; A comment.
(define-record-type <comment>
(comment str margin?)
comment?
(str comment->string)
(margin? comment-margin?))
(define (read-with-comments port)
"Like 'read', but include <comment> objects when they're encountered."
;; Note: Instead of implementing this functionality in 'read' proper, which
;; is the best approach long-term, this code is a later on top of 'read',
;; such that we don't have to rely on a specific Guile version.
(let loop ((blank-line? #t)
(return (const 'unbalanced)))
(match (read-char port)
((? eof-object? eof)
eof) ;oops!
(chr
(cond ((eqv? chr #\newline)
(loop #t return))
((char-set-contains? char-set:whitespace chr)
(loop blank-line? return))
((memv chr '(#\( #\[))
(let/ec return
(let liip ((lst '()))
(liip (cons (loop (match lst
(((? comment?) . _) #t)
(_ #f))
(lambda ()
(return (reverse lst))))
lst)))))
((memv chr '(#\) #\]))
(return))
((eq? chr #\')
(list 'quote (loop #f return)))
((eq? chr #\`)
(list 'quasiquote (loop #f return)))
((eq? chr #\,)
(list (match (peek-char port)
(#\@
(read-char port)
'unquote-splicing)
(_
'unquote))
(loop #f return)))
((eqv? chr #\;)
(unread-char chr port)
(comment (read-line port 'concat)
(not blank-line?)))
(else
(unread-char chr port)
(read port)))))))
;;;
;;; Comment-preserving pretty-printer.
;;;
(define* (pretty-print-with-comments port obj
#:key
(indent 0)
(max-width 78)
(long-list 5))
(let loop ((indent indent)
(column indent)
(delimited? #t) ;true if comes after a delimiter
(obj obj))
(match obj
((? comment? comment)
(if (comment-margin? comment)
(begin
(display " " port)
(display (comment->string comment) port))
(begin
;; When already at the beginning of a line, for example because
;; COMMENT follows a margin comment, no need to emit a newline.
(unless (= column indent)
(newline port)
(display (make-string indent #\space) port))
(display (comment->string comment) port)))
(display (make-string indent #\space) port)
indent)
(('quote lst)
(unless delimited? (display " " port))
(display "'" port)
(loop indent (+ column (if delimited? 1 2)) #t lst))
(('quasiquote lst)
(unless delimited? (display " " port))
(display "`" port)
(loop indent (+ column (if delimited? 1 2)) #t lst))
(('unquote lst)
(unless delimited? (display " " port))
(display "," port)
(loop indent (+ column (if delimited? 1 2)) #t lst))
(('modify-inputs inputs clauses ...)
;; Special-case 'modify-inputs' to have one clause per line and custom
;; indentation.
(let ((head "(modify-inputs "))
(display head port)
(loop (+ indent 4)
(+ column (string-length head))
#t
inputs)
(let* ((indent (+ indent 2))
(column (fold (lambda (clause column)
(newline port)
(display (make-string indent #\space)
port)
(loop indent indent #t clause))
indent
clauses)))
(display ")" port)
(+ column 1))))
((head tail ...)
(unless delimited? (display " " port))
(display "(" port)
(let* ((new-column (loop indent (+ 1 column) #t head))
(indent (+ indent (- new-column column)))
(long? (> (length tail) long-list)))
(define column
(fold2 (lambda (item column first?)
(define newline?
;; Insert a newline if ITEM is itself a list, or if TAIL
;; is long, but only if ITEM is not the first item.
(and (or (pair? item) long?)
(not first?) (not (comment? item))))
(when newline?
(newline port)
(display (make-string indent #\space) port))
(let ((column (if newline? indent column)))
(values (loop indent
column
(= column indent)
item)
(comment? item))))
(+ 1 new-column)
#t ;first
tail))
(display ")" port)
(+ column 1)))
(_
(let* ((str (object->string obj))
(len (string-length str)))
(if (> (+ column 1 len) max-width)
(begin
(newline port)
(display (make-string indent #\space) port)
(display str port)
(+ indent len))
(begin
(unless delimited? (display " " port))
(display str port)
(+ column (if delimited? 1 2) len))))))))
(define (object->string* obj indent)
(call-with-output-string
(lambda (port)
(pretty-print-with-comments port obj
#:indent indent))))
;;;
;;; Simplifying input expressions.
;;;
(define (label-matches? label name)
"Return true if LABEL matches NAME, a package name."
(or (string=? label name)
(and (string-prefix? "python-" label)
(string-prefix? "python2-" name)
(string=? (string-drop label (string-length "python-"))
(string-drop name (string-length "python2-"))))))
(define* (simplify-inputs location package str inputs
#:key (label-matches? label-matches?))
"Simplify the inputs field of PACKAGE (a string) at LOCATION; its current
value is INPUTS the corresponding source code is STR. Return a string to
replace STR."
(define (simplify-input-expression return)
(match-lambda
((label ('unquote symbol)) symbol)
((label ('unquote symbol) output)
(list 'quasiquote
(list (list 'unquote symbol) output)))
(_
;; Expression doesn't look like a simple input.
(warning location (G_ "~a: complex expression, \
bailing out~%")
package)
(return str))))
(define (simplify-input exp input return)
(define package* package)
(match input
((or ((? string? label) (? package? package))
((? string? label) (? package? package)
(? string?)))
;; If LABEL doesn't match PACKAGE's name, then simplifying would incur
;; a rebuild, and perhaps it would break build-side code relying on
;; this specific label.
(if (label-matches? label (package-name package))
((simplify-input-expression return) exp)
(begin
(warning location (G_ "~a: input label \
'~a' does not match package name, bailing out~%")
package* label)
(return str))))
(_
(warning location (G_ "~a: non-trivial input, \
bailing out~%")
package*)
(return str))))
(define (simplify-expressions exp inputs return)
;; Simplify the expressions in EXP, which correspond to INPUTS, and return
;; a list of expressions. Call RETURN with a string when bailing out.
(let loop ((result '())
(exp exp)
(inputs inputs))
(match exp
(((? comment? head) . rest)
(loop (cons head result) rest inputs))
((head . rest)
(match inputs
((input . inputs)
;; HEAD (an sexp) and INPUT (an input tuple) are correlated.
(loop (cons (simplify-input head input return) result)
rest inputs))
(()
;; If EXP and INPUTS have a different length, that
;; means EXP is a non-trivial input list, for example
;; with input-splicing, conditionals, etc.
(warning location (G_ "~a: input expression is too short~%")
package)
(return str))))
(()
;; It's possible for EXP to contain fewer elements than INPUTS, for
;; example in the case of input splicing. No bailout here. (XXX)
(reverse result)))))
(define inputs-exp
(call-with-input-string str read-with-comments))
(match inputs-exp
(('list _ ...) ;already done
str)
(('modify-inputs _ ...) ;already done
str)
(('quasiquote ;prepending inputs
(exp ...
('unquote-splicing
((and symbol (or 'package-inputs 'package-native-inputs
'package-propagated-inputs))
arg))))
(let/ec return
(object->string*
(let ((things (simplify-expressions exp inputs return)))
`(modify-inputs (,symbol ,arg)
(prepend ,@things)))
(location-column location))))
(('quasiquote ;replacing an input
((and exp ((? string? to-delete) ('unquote replacement)))
('unquote-splicing
('alist-delete (? string? to-delete)
((and symbol
(or 'package-inputs 'package-native-inputs
'package-propagated-inputs))
arg)))))
(let/ec return
(object->string*
(let ((things (simplify-expressions (list exp)
(list (car inputs))
return)))
`(modify-inputs (,symbol ,arg)
(replace ,to-delete ,replacement)))
(location-column location))))
(('quasiquote ;removing an input
(exp ...
('unquote-splicing
('alist-delete (? string? to-delete)
((and symbol
(or 'package-inputs 'package-native-inputs
'package-propagated-inputs))
arg)))))
(let/ec return
(object->string*
(let ((things (simplify-expressions exp inputs return)))
`(modify-inputs (,symbol ,arg)
(delete ,to-delete)
(prepend ,@things)))
(location-column location))))
(('fold 'alist-delete ;removing several inputs
((and symbol
(or 'package-inputs 'package-native-inputs
'package-propagated-inputs))
arg)
('quote ((? string? to-delete) ...)))
(object->string*
`(modify-inputs (,symbol ,arg)
(delete ,@to-delete))
(location-column location)))
(('quasiquote ;removing several inputs and adding others
(exp ...
('unquote-splicing
('fold 'alist-delete
((and symbol
(or 'package-inputs 'package-native-inputs
'package-propagated-inputs))
arg)
('quote ((? string? to-delete) ...))))))
(let/ec return
(object->string*
(let ((things (simplify-expressions exp inputs return)))
`(modify-inputs (,symbol ,arg)
(delete ,@to-delete)
(prepend ,@things)))
(location-column location))))
(('quasiquote (exp ...))
(let/ec return
(object->string*
`(list ,@(simplify-expressions exp inputs return))
(location-column location))))
(_
(warning location (G_ "~a: unsupported input style, \
bailing out~%")
package)
str)))
(define* (simplify-package-inputs package
#:key (policy 'silent))
"Edit the source code of PACKAGE to simplify its inputs field if needed.
POLICY is a symbol that defines whether to simplify inputs; it can one of
'silent (change only if the resulting derivation is the same), 'safe (change
only if semantics are known to be unaffected), and 'always (fearlessly
simplify inputs!)."
(for-each (lambda (field-name field)
(match (field package)
(()
#f)
(inputs
(match (package-field-location package field-name)
(#f
;; If the location of FIELD-NAME is not found, it may be
;; that PACKAGE inherits from another package.
#f)
(location
(edit-expression
(location->source-properties location)
(lambda (str)
(define matches?
(match policy
('silent
;; Simplify inputs only when the label matches
;; perfectly, such that the resulting derivation
;; is unchanged.
label-matches?)
('safe
;; If PACKAGE has no arguments, labels are known
;; to have no effect: this is a "safe" change, but
;; it may change the derivation.
(if (null? (package-arguments package))
(const #t)
label-matches?))
('always
;; Assume it's gonna be alright.
(const #f))))
(simplify-inputs location
(package-name package)
str inputs
#:label-matches? matches?))))))))
'(inputs native-inputs propagated-inputs)
(list package-inputs package-native-inputs
package-propagated-inputs)))
(define (package-location<? p1 p2)
"Return true if P1's location is \"before\" P2's."
(let ((loc1 (package-location p1))
(loc2 (package-location p2)))
(and loc1 loc2
(if (string=? (location-file loc1) (location-file loc2))
(< (location-line loc1) (location-line loc2))
(string<? (location-file loc1) (location-file loc2))))))
;;;
;;; Options.
;;;
(define %options
;; Specification of the command-line options.
(list (find (lambda (option)
(member "load-path" (option-names option)))
%standard-build-options)
(option '(#\e "expression") #t #f
(lambda (opt name arg result)
(alist-cons 'expression arg result)))
(option '("input-simplification") #t #f
(lambda (opt name arg result)
(let ((symbol (string->symbol arg)))
(unless (memq symbol '(silent safe always))
(leave (G_ "~a: invalid input simplification policy~%")
arg))
(alist-cons 'input-simplification-policy symbol
result))))
(option '(#\h "help") #f #f
(lambda args
(show-help)
(exit 0)))
(option '(#\V "version") #f #f
(lambda args
(show-version-and-exit "guix style")))))
(define (show-help)
(display (G_ "Usage: guix style [OPTION]... [PACKAGE]...
Update package definitions to the latest style.\n"))
(display (G_ "
-L, --load-path=DIR prepend DIR to the package module search path"))
(display (G_ "
-e, --expression=EXPR consider the package EXPR evaluates to"))
(display (G_ "
--input-simplification=POLICY
follow POLICY for package input simplification, one
of 'silent', 'safe', or 'always'"))
(newline)
(display (G_ "
-h, --help display this help and exit"))
(display (G_ "
-V, --version display version information and exit"))
(newline)
(show-bug-report-information))
(define %default-options
;; Alist of default option values.
'((input-simplification-policy . silent)))
;;;
;;; Entry point.
;;;
(define-command (guix-style . args)
(category packaging)
(synopsis "update the style of package definitions")
(define (parse-options)
;; Return the alist of option values.
(parse-command-line args %options (list %default-options)
#:build-options? #f))
(let* ((opts (parse-options))
(packages (filter-map (match-lambda
(('argument . spec)
(specification->package spec))
(('expression . str)
(read/eval str))
(_ #f))
opts))
(policy (assoc-ref opts 'input-simplification-policy)))
(for-each (lambda (package)
(simplify-package-inputs package #:policy policy))
;; Sort package by source code location so that we start editing
;; files from the bottom and going upward. That way, the
;; 'location' field of <package> records is not invalidated as
;; we modify files.
(sort (if (null? packages)
(fold-packages cons '() #:select? (const #t))
packages)
(negate package-location<?)))))