summary refs log tree commit diff
path: root/doc/build.scm
blob: a9e279159b21a55c79daddeead29a90f1859e584 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2019, 2020, 2021 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2020 Björn Höfling <bjoern.hoefling@bjoernhoefling.de>
;;;
;;; 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/>.


;; This file contains machinery to build HTML and PDF copies of the manual
;; that can be readily published on the web site.  To do that, run:
;;
;;  guix build -f build.scm
;;
;; The result is a directory hierarchy that can be used as the manual/
;; sub-directory of the web site.

(use-modules (guix)
             (guix gexp)
             (guix git)
             (guix git-download)
             (guix utils)
             (git)
             (gnu packages base)
             (gnu packages compression)
             (gnu packages gawk)
             (gnu packages gettext)
             (gnu packages guile)
             (gnu packages guile-xyz)
             (gnu packages iso-codes)
             (gnu packages texinfo)
             (gnu packages tex)
             (ice-9 match)
             (srfi srfi-1)
             (srfi srfi-19)
             (srfi srfi-26)
             (srfi srfi-71))

(define file-append*
  (@@ (guix self) file-append*))

(define translated-texi-manuals
  (let ((translated (@@ (guix self) translate-texi-manuals)))
    (lambda (source)
      (let ((result (translated source)))
        ;; Build with 'guile-3.0-latest', which is linked against
        ;; 'libgc/disable-munmap', to avoid the dreaded "mmap(PROT_NONE)
        ;; failed" crash: <https://bugs.gnu.org/47428>.
        (computed-file (computed-file-name result)
                       (computed-file-gexp result)
                       #:local-build? #f
                       #:options (computed-file-options result)
                       #:guile guile-3.0-latest)))))

(define info-manual
  (@@ (guix self) info-manual))

(define %manual
  ;; The manual to build--i.e., the base name of a .texi file, such as "guix"
  ;; or "guix-cookbook".
  (or (getenv "GUIX_MANUAL")
      "guix"))

(define %languages
  ;; The cookbook is not translated in the same languages as the manual
  (if (string=? %manual "guix-cookbook")
      '("de" "en" "fr")
      '("de" "en" "es" "fr" "ru" "zh_CN")))

(define (texinfo-manual-images source)
  "Return a directory containing all the images used by the user manual, taken
from SOURCE, the root of the source tree."
  (define graphviz
    (module-ref (resolve-interface '(gnu packages graphviz))
                'graphviz))

  (define images
    (file-append* source "doc/images"))

  (define build
    (with-imported-modules '((guix build utils))
      #~(begin
          (use-modules (guix build utils)
                       (srfi srfi-26))

          (define (dot->image dot-file format)
            (invoke #+(file-append graphviz "/bin/dot")
                    "-T" format "-Gratio=.9" "-Gnodesep=.005"
                    "-Granksep=.00005" "-Nfontsize=9"
                    "-Nheight=.1" "-Nwidth=.1"
                    "-o" (string-append #$output "/"
                                        (basename dot-file ".dot")
                                        "." format)
                    dot-file))

          ;; Build graphs.
          (mkdir-p #$output)
          (for-each (lambda (dot-file)
                      (for-each (cut dot->image dot-file <>)
                                '("png" "pdf")))
                    (find-files #$images "\\.dot$"))

          ;; Copy other PNGs.
          (for-each (lambda (png-file)
                      (install-file png-file #$output))
                    (find-files #$images "\\.png$")))))

  (computed-file "texinfo-manual-images" build))

(define* (texinfo-manual-source source #:key
                                (version "0.0")
                                (languages %languages)
                                (date 1))
  "Gather all the source files of the Texinfo manuals from SOURCE--.texi file
as well as images, OS examples, and translations."
  (define documentation
    (file-append* source "doc"))

  (define examples
    (file-append* source "gnu/system/examples"))

  (define build
    (with-imported-modules '((guix build utils))
      #~(begin
          (use-modules (guix build utils)
                       (srfi srfi-19))

          (define (make-version-texi language)
            ;; Create the 'version.texi' file for LANGUAGE.
            (let ((file (if (string=? language "en")
                            "version.texi"
                            (string-append "version-" language ".texi"))))
              (call-with-output-file (string-append #$output "/" file)
                (lambda (port)
                  (let* ((version #$version)
                         (time    (make-time time-utc 0 #$date))
                         (date    (time-utc->date time)))
                    (format port "
@set UPDATED ~a
@set UPDATED-MONTH ~a
@set EDITION ~a
@set VERSION ~a\n"
                            (date->string date "~e ~B ~Y")
                            (date->string date "~B ~Y")
                            version version))))))

          (install-file #$(file-append documentation "/htmlxref.cnf")
                        #$output)

          (for-each (lambda (texi)
                      (install-file texi #$output))
                    (append (find-files #$documentation "\\.(texi|scm|json)$")
                            (find-files #$(translated-texi-manuals source)
                                        "\\.texi$")))

          ;; Create 'version.texi'.
          (for-each make-version-texi '#$languages)

          ;; Copy configuration templates that the manual includes.
          (for-each (lambda (template)
                      (copy-file template
                                 (string-append
                                  #$output "/os-config-"
                                  (basename template ".tmpl")
                                  ".texi")))
                    (find-files #$examples "\\.tmpl$"))

          (symlink #$(texinfo-manual-images source)
                   (string-append #$output "/images")))))

  (computed-file "texinfo-manual-source" build))

(define %web-site-url
  ;; URL of the web site home page.
  (or (getenv "GUIX_WEB_SITE_URL")
      "/software/guix/"))

(define %makeinfo-html-options
  ;; Options passed to 'makeinfo --html'.
  '("--css-ref=https://www.gnu.org/software/gnulib/manual.css"
    "-c" "EXTRA_HEAD=<meta name=\"viewport\" \
content=\"width=device-width, initial-scale=1\" />"))

(define (normalize-language-code language)        ;XXX: deduplicate
  ;; Normalize LANGUAGE.  For instance, "zh_CN" becomes "zh-cn".
  (string-map (match-lambda
                (#\_ #\-)
                (chr chr))
              (string-downcase language)))

(define* (html-manual-identifier-index manual base-url
                                       #:key
                                       (name "html-manual-identifier-index"))
  "Return an index of all the identifiers that appear in MANUAL, a
makeinfo-generated manual.  The index is a file that contains an alist; each
key is an identifier and the associated value is the URL reference pointing to
that identifier.  The URL is constructed by concatenating BASE-URL to the
actual file name."
  (define build
    (with-extensions (list guile-lib)
      (with-imported-modules '((guix build utils))
        #~(begin
            (use-modules (guix build utils)
                         (htmlprag)
                         (srfi srfi-1)
                         (srfi srfi-26)
                         (ice-9 ftw)
                         (ice-9 match)
                         (ice-9 threads)
                         (ice-9 pretty-print))

            (%strict-tokenizer? #t)

            (define file-url
              (let ((prefix (string-append #$manual "/")))
                (lambda (file)
                  ;; Return the URL for FILE.
                  (let ((file (string-drop file (string-length prefix)))
                        (base #$base-url))
                    (if (string-null? base)
                        file
                        (string-append base "/" file))))))

            (define (underscore-decode str)
              ;; Decode STR, an "underscore-encoded" string as produced by
              ;; makeinfo for indexes, such as "_0025base_002dservices" for
              ;; "%base-services".
              (let loop ((str str)
                         (result '()))
                (match (string-index str #\_)
                  (#f
                   (string-concatenate-reverse (cons str result)))
                  (index
                   (let ((char (string->number
                                (substring str (+ index 1) (+ index 5))
                                16)))
                     (loop (string-drop str (+ index 5))
                           (append (list (string (integer->char char))
                                         (string-take str index))
                                   result)))))))

            (define (anchor-id->key id)
              ;; Convert ID, an anchor ID such as
              ;; "index-pam_002dlimits_002dservice" to the corresponding key,
              ;; "pam-limits-service" in this example.  Drop the suffix of
              ;; duplicate anchor IDs like "operating_002dsystem-1".
              (let ((id (if (any (cut string-suffix? <> id)
                                 '("-1" "-2" "-3" "-4" "-5"))
                            (string-drop-right id 2)
                            id)))
                (underscore-decode
                 (string-drop id (string-length "index-")))))

            (define* (collect-anchors file #:optional (anchors '()))
              ;; Collect the anchors that appear in FILE, a makeinfo-generated
              ;; file.  Grab those from <dt> tags, which corresponds to
              ;; Texinfo @deftp, @defvr, etc.  Return ANCHORS augmented with
              ;; more name/reference pairs.
              (define string-or-entity?
                (match-lambda
                  ((? string?) #t)
                  (('*ENTITY* _ ...) #t)
                  (_ #f)))

              (define (worthy-entry? lst)
                ;; Attempt to match:
                ;;   Scheme Variable: <strong>x</strong>
                ;; but not:
                ;;   <code>cups-configuration</code> parameter: …
                (let loop ((lst lst))
                  (match lst
                    (((? string-or-entity?) rest ...)
                     (loop rest))
                    ((('strong _ ...) _ ...)
                     #t)
                    ((('span ('@ ('class "symbol-definition-category"))
                             (? string-or-entity?) ...) rest ...)
                     #t)
                    (x
                     #f))))

              (let ((shtml (call-with-input-file file html->shtml)))
                (let loop ((shtml shtml)
                           (anchors anchors))
                  (match shtml
                    (('dt ('@ ('id id) _ ...) rest ...)
                     (if (and (string-prefix? "index-" id)
                              (worthy-entry? rest))
                         (alist-cons (anchor-id->key id)
                                     (string-append (file-url file)
                                                    "#" id)
                                     anchors)
                         anchors))
                    ((tag ('@ _ ...) body ...)
                     (fold loop anchors body))
                    ((tag body ...)
                     (fold loop anchors body))
                    (_ anchors)))))

            (define (html-files directory)
              ;; Return the list of HTML files under DIRECTORY.
              (map (cut string-append directory "/" <>)
                   (scandir #$manual (lambda (file)
                                       (string-suffix? ".html" file)))))

            (define anchors
              (sort (concatenate
                     (n-par-map (parallel-job-count)
                                (cut collect-anchors <>)
                                (html-files #$manual)))
                    (match-lambda*
                      (((key1 . url1) (key2 . url2))
                       (if (string=? key1 key2)
                           (string<? url1 url2)
                           (string<? key1 key2))))))

            (call-with-output-file #$output
              (lambda (port)
                (display ";; Identifier index for the manual.\n\n"
                         port)
                (pretty-print anchors port)))))))

  (computed-file name build))

(define* (html-identifier-indexes manual directory-suffix
                                  #:key (languages %languages)
                                  (manual-name %manual)
                                  (base-url (const "")))
  (map (lambda (language)
         (let ((language (normalize-language-code language)))
           (list language
                 (html-manual-identifier-index
                  (file-append manual "/" language directory-suffix)
                  (base-url language)
                  #:name (string-append manual-name "-html-index-"
                                        language)))))
       languages))

(define* (syntax-highlighted-html input
                                  #:key
                                  (name "highlighted-syntax")
                                  (languages %languages)
                                  (mono-node-indexes
                                   (html-identifier-indexes input ""
                                                            #:languages
                                                            languages))
                                  (split-node-indexes
                                   (html-identifier-indexes input
                                                            "/html_node"
                                                            #:languages
                                                            languages))
                                  (syntax-css-url
                                   "/static/base/css/code.css"))
  "Return a derivation called NAME that processes all the HTML files in INPUT
to (1) add them a link to SYNTAX-CSS-URL, and (2) highlight the syntax of all
its <pre class=\"lisp\"> blocks (as produced by 'makeinfo --html')."
  (define build
    (with-extensions (list guile-lib guile-syntax-highlight)
      (with-imported-modules '((guix build utils))
        #~(begin
            (use-modules (htmlprag)
                         (syntax-highlight)
                         (syntax-highlight scheme)
                         (syntax-highlight lexers)
                         (guix build utils)
                         (srfi srfi-1)
                         (srfi srfi-26)
                         (ice-9 match)
                         (ice-9 threads)
                         (ice-9 vlist))

            (%strict-tokenizer? #t)

            (define (pair-open/close lst)
              ;; Pair 'open' and 'close' tags produced by 'highlights' and
              ;; produce nested 'paren' tags instead.
              (let loop ((lst lst)
                         (level 0)
                         (result '()))
                (match lst
                  ((('open open) rest ...)
                   (call-with-values
                       (lambda ()
                         (loop rest (+ 1 level) '()))
                     (lambda (inner close rest)
                       (loop rest level
                             (cons `(paren ,level ,open ,inner ,close)
                                   result)))))
                  ((('close str) rest ...)
                   (if (> level 0)
                       (values (reverse result) str rest)
                       (begin
                         (format (current-error-port)
                                 "warning: extra closing paren; context:~% ~y~%"
                                 (reverse result))
                         (loop rest 0 (cons `(close ,str) result)))))
                  ((item rest ...)
                   (loop rest level (cons item result)))
                  (()
                   (when (> level 0)
                     (format (current-error-port)
                             "warning: missing ~a closing parens; context:~% ~y%"
                             level (reverse result)))
                   (values (reverse result) "" '())))))

            (define (highlights->sxml* highlights anchors)
              ;; Like 'highlights->sxml', but handle nested 'paren tags.  This
              ;; allows for paren matching highlights via appropriate CSS
              ;; "hover" properties.  When a symbol is encountered, look it up
              ;; in ANCHORS, a vhash, and emit the corresponding href, if any.
              (define (tag->class tag)
                (string-append "syntax-" (symbol->string tag)))

              (map (match-lambda
                     ((? string? str) str)
                     (('paren level open (body ...) close)
                      `(span (@ (class ,(string-append "syntax-paren"
                                                       (number->string level))))
                             ,open
                             (span (@ (class "syntax-symbol"))
                                   ,@(highlights->sxml* body anchors))
                             ,close))
                     (('symbol text)
                      ;; Check whether we can emit a hyperlink for TEXT.
                      (match (vhash-assoc text anchors)
                        (#f
                         `(span (@ (class ,(tag->class 'symbol))) ,text))
                        ((_ . target)
                         `(a (@ (class ,(tag->class 'symbol)) (href ,target))
                             ,text))))
                     ((tag text)
                      `(span (@ (class ,(tag->class tag))) ,text)))
                   highlights))

            (define entity->string
              (match-lambda
                ("rArr"   "⇒")
                ("rarr"   "→")
                ("hellip" "…")
                ("rsquo"  "’")
                (e (pk 'unknown-entity e) (primitive-exit 2))))

            (define (concatenate-snippets pieces)
              ;; Concatenate PIECES, which contains strings and entities,
              ;; replacing entities with their corresponding string.
              (let loop ((pieces pieces)
                         (strings '()))
                (match pieces
                  (()
                   (string-concatenate-reverse strings))
                  (((? string? str) . rest)
                   (loop rest (cons str strings)))
                  ((('*ENTITY* "additional" entity) . rest)
                   (loop rest (cons (entity->string entity) strings)))
                  ((('span _ lst ...) . rest)     ;for <span class="roman">
                   (loop (append lst rest) strings))
                  ((('var name) . rest)           ;for @var{name} within @lisp
                   (loop rest (cons name strings))) ;XXX: losing formatting
                  (something
                   (pk 'unsupported-code-snippet something)
                   (primitive-exit 1)))))

            (define (highlight-definition id category symbol args)
              ;; Produce stylable HTML for the given definition (an @deftp,
              ;; @deffn, or similar).
              `(dt (@ (id ,id) (class "symbol-definition"))
                   (span (@ (class "symbol-definition-category"))
                         ,@category)
                   (span (@ (class "symbol-definition-prototype"))
                         ,symbol " " ,@args)))

            (define (space? obj)
              (and (string? obj)
                   (string-every char-set:whitespace obj)))

            (define (syntax-highlight sxml anchors)
              ;; Recurse over SXML and syntax-highlight code snippets.
              (let loop ((sxml sxml))
                (match sxml
                  (('*TOP* decl body ...)
                   `(*TOP* ,decl ,@(map loop body)))
                  (('head things ...)
                   `(head ,@things
                          (link (@ (rel "stylesheet")
                                   (type "text/css")
                                   (href #$syntax-css-url)))))
                  (('pre ('@ ('class "lisp")) code-snippet ...)
                   `(pre (@ (class "lisp"))
                         ,@(highlights->sxml*
                            (pair-open/close
                             (highlight lex-scheme
                                        (concatenate-snippets code-snippet)))
                            anchors)))

                  ;; Replace the ugly <strong> used for @deffn etc., which
                  ;; translate to <dt>, with more stylable markup.
                  (('dt (@ ('id id)) category ... ('strong thing))
                   (highlight-definition id category thing '()))
                  (('dt (@ ('id id)) category ... ('strong thing)
                        (? space?) ('em args ...))
                   (highlight-definition id category thing args))

                  ((tag ('@ attributes ...) body ...)
                   `(,tag (@ ,@attributes) ,@(map loop body)))
                  ((tag body ...)
                   `(,tag ,@(map loop body)))
                  ((? string? str)
                   str))))

            (define (process-html file anchors)
              ;; Parse FILE and perform syntax highlighting for its Scheme
              ;; snippets.  Install the result to #$output.
              (format (current-error-port) "processing ~a...~%" file)
              (let* ((shtml        (call-with-input-file file html->shtml))
                     (highlighted  (syntax-highlight shtml anchors))
                     (base         (string-drop file (string-length #$input)))
                     (target       (string-append #$output base)))
                (mkdir-p (dirname target))
                (call-with-output-file target
                  (lambda (port)
                    (write-shtml-as-html highlighted port)))))

            (define (copy-as-is file)
              ;; Copy FILE as is to #$output.
              (let* ((base   (string-drop file (string-length #$input)))
                     (target (string-append #$output base)))
                (mkdir-p (dirname target))
                (catch 'system-error
                  (lambda ()
                    (if (eq? 'symlink (stat:type (lstat file)))
                        (symlink (readlink file) target)
                        (link file target)))
                  (lambda args
                    (let ((errno (system-error-errno args)))
                      (pk 'error-link file target (strerror errno))
                      (primitive-exit 3))))))

            (define (html? file stat)
              (string-suffix? ".html" file))

            (define language+node-anchors
              (match-lambda
                ((language files ...)
                 (cons language
                       (fold (lambda (file vhash)
                               (let ((alist (call-with-input-file file read)))
                                 ;; Use 'fold-right' so that the first entry
                                 ;; wins (e.g., "car" from "Pairs" rather than
                                 ;; from "rnrs base" in the Guile manual).
                                 (fold-right (match-lambda*
                                               (((key . value) vhash)
                                                (vhash-cons key value vhash)))
                                             vhash
                                             alist)))
                             vlist-null
                             files)))))

            (define mono-node-anchors
              ;; List of language/vhash pairs, where each vhash maps an
              ;; identifier to the corresponding URL in a single-page manual.
              (map language+node-anchors '#$mono-node-indexes))

            (define multi-node-anchors
              ;; Likewise for split-node manuals.
              (map language+node-anchors '#$split-node-indexes))

            ;; Install a UTF-8 locale so we can process UTF-8 files.
            (setenv "GUIX_LOCPATH"
                    #+(file-append glibc-utf8-locales "/lib/locale"))
            (setlocale LC_ALL "en_US.utf8")

            ;; First process the mono-node 'guix.html' files.
            (for-each (match-lambda
                        ((language . anchors)
                         (let ((files (find-files
                                       (string-append #$input "/" language)
                                       "^guix(-cookbook|)(\\.[a-zA-Z_-]+)?\\.html$")))
                           (n-par-for-each (parallel-job-count)
                                           (cut process-html <> anchors)
                                           files))))
                      mono-node-anchors)

            ;; Process the multi-node HTML files.
            (for-each (match-lambda
                        ((language . anchors)
                         (let ((files (find-files
                                       (string-append #$input "/" language
                                                      "/html_node")
                                       "\\.html$")))
                           (n-par-for-each (parallel-job-count)
                                           (cut process-html <> anchors)
                                           files))))
                      multi-node-anchors)

            ;; Last, copy non-HTML files as is.
            (for-each copy-as-is
                      (find-files #$input (negate html?)))))))

  (computed-file name build))

(define* (html-manual source #:key (languages %languages)
                      (version "0.0")
                      (manual %manual)
                      (mono-node-indexes (map list languages))
                      (split-node-indexes (map list languages))
                      (date 1)
                      (options %makeinfo-html-options))
  "Return the HTML manuals built from SOURCE for all LANGUAGES, with the given
makeinfo OPTIONS."
  (define manual-source
    (texinfo-manual-source source
                           #:version version
                           #:languages languages
                           #:date date))

  (define images
    (texinfo-manual-images source))

  (define build
    (with-imported-modules '((guix build utils))
      #~(begin
          (use-modules (guix build utils)
                       (ice-9 match))

          (define (normalize language)
            ;; Normalize LANGUAGE.  For instance, "zh_CN" becomes "zh-cn".
            (string-map (match-lambda
                          (#\_ #\-)
                          (chr chr))
                        (string-downcase language)))

          (define (language->texi-file-name language)
            (if (string=? language "en")
                (string-append #$manual-source "/"
                               #$manual ".texi")
                (string-append #$manual-source "/"
                               #$manual "." language ".texi")))

          ;; Install a UTF-8 locale so that 'makeinfo' is at ease.
          (setenv "GUIX_LOCPATH"
                  #+(file-append glibc-utf8-locales "/lib/locale"))
          (setenv "LC_ALL" "en_US.utf8")

          (setvbuf (current-output-port) 'line)
          (setvbuf (current-error-port) 'line)

          ;; 'makeinfo' looks for "htmlxref.cnf" in the current directory, so
          ;; copy it right here.
          (copy-file (string-append #$manual-source "/htmlxref.cnf")
                     "htmlxref.cnf")

          (for-each (lambda (language)
                      (let* ((texi (language->texi-file-name language))
                             (opts `("--html"
                                     "-c" ,(string-append "TOP_NODE_UP_URL=/manual/"
                                                         language)
                                     #$@options
                                     ,texi)))
                        (format #t "building HTML manual for language '~a'...~%"
                                language)
                        (mkdir-p (string-append #$output "/"
                                                (normalize language)))
                        (setenv "LANGUAGE" language)
                        (apply invoke #$(file-append texinfo "/bin/makeinfo")
                               "-o" (string-append #$output "/"
                                                   (normalize language)
                                                   "/html_node")
                               opts)
                        (apply invoke #$(file-append texinfo "/bin/makeinfo")
                               "--no-split"
                               "-o"
                               (string-append #$output "/"
                                              (normalize language)
                                              "/" #$manual
                                              (if (string=? language "en")
                                                  ""
                                                  (string-append "." language))
                                              ".html")
                               opts)

                        ;; Make sure images are available.
                        (symlink #$images
                                 (string-append #$output "/" (normalize language)
                                                "/images"))
                        (symlink #$images
                                 (string-append #$output "/" (normalize language)
                                                "/html_node/images"))))
                    (filter (compose file-exists? language->texi-file-name)
                            '#$languages)))))

  (let* ((name   (string-append manual "-html-manual"))
         (manual (computed-file name build #:local-build? #f)))
    (syntax-highlighted-html manual
                             #:mono-node-indexes mono-node-indexes
                             #:split-node-indexes split-node-indexes
                             #:name (string-append name "-highlighted"))))

(define* (pdf-manual source #:key (languages %languages)
                     (version "0.0")
                     (manual %manual)
                     (date 1)
                     (options '()))
  "Return the HTML manuals built from SOURCE for all LANGUAGES, with the given
makeinfo OPTIONS."
  (define manual-source
    (texinfo-manual-source source
                           #:version version
                           #:languages languages
                           #:date date))

  ;; FIXME: This union works, except for the table of contents of non-English
  ;; manuals, which contains escape sequences like "^^ca^^fe" instead of
  ;; accented letters.
  ;;
  ;; (define texlive
  ;;   (texlive-union (list texlive-tex-texinfo
  ;;                        texlive-generic-epsf
  ;;                        texlive-fonts-ec)))

  (define build
    (with-imported-modules '((guix build utils))
      #~(begin
          (use-modules (guix build utils)
                       (srfi srfi-34)
                       (ice-9 match))

          (define (normalize language)            ;XXX: deduplicate
            ;; Normalize LANGUAGE.  For instance, "zh_CN" becomes "zh-cn".
            (string-map (match-lambda
                          (#\_ #\-)
                          (chr chr))
                        (string-downcase language)))

          ;; Install a UTF-8 locale so that 'makeinfo' is at ease.
          (setenv "GUIX_LOCPATH"
                  #+(file-append glibc-utf8-locales "/lib/locale"))
          (setenv "LC_ALL" "en_US.utf8")
          (setenv "PATH"
                  (string-append #+(file-append texlive "/bin") ":"
                                 #+(file-append texinfo "/bin") ":"

                                 ;; Below are command-line tools needed by
                                 ;; 'texi2dvi' and friends.
                                 #+(file-append sed "/bin") ":"
                                 #+(file-append grep "/bin") ":"
                                 #+(file-append coreutils "/bin") ":"
                                 #+(file-append gawk "/bin") ":"
                                 #+(file-append tar "/bin") ":"
                                 #+(file-append diffutils "/bin")))

          (setvbuf (current-output-port) 'line)
          (setvbuf (current-error-port) 'line)

          (setenv "HOME" (getcwd))                ;for kpathsea/mktextfm

          ;; 'SOURCE_DATE_EPOCH' is honored by pdftex.
          (setenv "SOURCE_DATE_EPOCH" "1")

          (for-each (lambda (language)
                      (let ((opts `("--pdf"
                                    "-I" "."
                                    #$@options
                                    ,(if (string=? language "en")
                                         (string-append #$manual-source "/"
                                                        #$manual ".texi")
                                         (string-append #$manual-source "/"
                                                        #$manual "." language ".texi")))))
                        (format #t "building PDF manual for language '~a'...~%"
                                language)
                        (mkdir-p (string-append #$output "/"
                                                (normalize language)))
                        (setenv "LANGUAGE" language)


                        ;; FIXME: Unfortunately building PDFs for non-Latin
                        ;; alphabets doesn't work:
                        ;; <https://lists.gnu.org/archive/html/help-texinfo/2012-01/msg00014.html>.
                        (guard (c ((invoke-error? c)
                                   (format (current-error-port)
                                           "~%~%Failed to produce \
PDF for language '~a'!~%~%"
                                           language)))
                         (apply invoke #$(file-append texinfo "/bin/makeinfo")
                                "--pdf" "-o"
                                (string-append #$output "/"
                                               (normalize language)
                                               "/" #$manual
                                               (if (string=? language "en")
                                                   ""
                                                   (string-append "."
                                                                  language))
                                               ".pdf")
                                opts))))
                    '#$languages))))

  (computed-file (string-append manual "-pdf-manual") build
                 #:local-build? #f))

(define (guix-manual-text-domain source languages)
  "Return the PO files for LANGUAGES of the 'guix-manual' text domain taken
from SOURCE."
  (define po-directory
    (file-append* source "/po/doc"))

  (define build
    (with-imported-modules '((guix build utils))
      #~(begin
          (use-modules (guix build utils))

          (mkdir-p #$output)
          (for-each (lambda (language)
                      (define directory
                        (string-append #$output "/" language
                                       "/LC_MESSAGES"))

                      (mkdir-p directory)
                      (invoke #+(file-append gnu-gettext "/bin/msgfmt")
                              "-c" "-o"
                              (string-append directory "/guix-manual.mo")
                              (string-append #$po-directory "/guix-manual."
                                             language ".po")))
                    '#$(delete "en" languages)))))

  (computed-file "guix-manual-po" build))

(define* (html-manual-indexes source
                              #:key (languages %languages)
                              (version "0.0")
                              (manual %manual)
                              (title (if (string=? "guix" manual)
                                         "GNU Guix Reference Manual"
                                         "GNU Guix Cookbook"))
                              (date 1))
  (define build
    (with-extensions (list guile-json-3)
      (with-imported-modules '((guix build utils))
        #~(begin
            (use-modules (guix build utils)
                         (json)
                         (ice-9 match)
                         (ice-9 popen)
                         (sxml simple)
                         (srfi srfi-1)
                         (srfi srfi-19))

            (define (normalize language)          ;XXX: deduplicate
              ;; Normalize LANGUAGE.  For instance, "zh_CN" becomes "zh-cn".
              (string-map (match-lambda
                            (#\_ #\-)
                            (chr chr))
                          (string-downcase language)))

            (define-syntax-rule (with-language language exp ...)
              (let ((lang (getenv "LANGUAGE")))
                (dynamic-wind
                  (lambda ()
                    (setenv "LANGUAGE" language)
                    (setlocale LC_MESSAGES))
                  (lambda () exp ...)
                  (lambda ()
                    (if lang
                        (setenv "LANGUAGE" lang)
                        (unsetenv "LANGUAGE"))
                    (setlocale LC_MESSAGES)))))

            ;; (put 'with-language 'scheme-indent-function 1)
            (define* (translate str language
                                #:key (domain "guix-manual"))
              (define exp
                `(begin
                   (bindtextdomain "guix-manual"
                                   #+(guix-manual-text-domain
                                      source
                                      languages))
                   (bindtextdomain "iso_639-3"    ;language names
                                   #+(file-append iso-codes
                                                  "/share/locale"))
                   (write (gettext ,str ,domain))))

              (with-language language
                ;; Since the 'gettext' function caches msgid translations,
                ;; regardless of $LANGUAGE, we have to spawn a new process each
                ;; time we want to translate to a different language.  Bah!
                (let* ((pipe (open-pipe* OPEN_READ
                                         #+(file-append guile-2.2
                                                        "/bin/guile")
                                         "-c" (object->string exp)))
                       (str  (read pipe)))
                  (close-pipe pipe)
                  str)))

            (define (seconds->string seconds language)
              (let* ((time (make-time time-utc 0 seconds))
                     (date (time-utc->date time)))
                (with-language language (date->string date "~e ~B ~Y"))))

            (define (guix-url path)
              (string-append #$%web-site-url path))

            (define (sxml-index language title body)
              ;; FIXME: Avoid duplicating styling info from guix-artwork.git.
              `(html (@ (lang ,language))
                     (head
                      (title ,(string-append title " — GNU Guix"))
                      (meta (@ (charset "UTF-8")))
                      (meta (@ (name "viewport") (content "width=device-width, initial-scale=1.0")))
                      ;; Menu prefetch.
                      (link (@ (rel "prefetch") (href ,(guix-url "menu/index.html"))))
                      ;; Base CSS.
                      (link (@ (rel "stylesheet") (href ,(guix-url "static/base/css/elements.css"))))
                      (link (@ (rel "stylesheet") (href ,(guix-url "static/base/css/common.css"))))
                      (link (@ (rel "stylesheet") (href ,(guix-url "static/base/css/messages.css"))))
                      (link (@ (rel "stylesheet") (href ,(guix-url "static/base/css/navbar.css"))))
                      (link (@ (rel "stylesheet") (href ,(guix-url "static/base/css/breadcrumbs.css"))))
                      (link (@ (rel "stylesheet") (href ,(guix-url "static/base/css/buttons.css"))))
                      (link (@ (rel "stylesheet") (href ,(guix-url "static/base/css/footer.css"))))

                      (link (@ (rel "stylesheet") (href ,(guix-url "static/base/css/page.css"))))
                      (link (@ (rel "stylesheet") (href ,(guix-url "static/base/css/post.css")))))
                     (body
                      (header (@ (class "navbar"))
                              (h1 (a (@ (class "branding")
                                        (href #$%web-site-url)))
                                  (span (@ (class "a11y-offset"))
                                        "Guix"))
                              (nav (@ (class "menu"))))
                      (nav (@ (class "breadcrumbs"))
                           (a (@ (class "crumb")
                                 (href #$%web-site-url))
                              "Home"))
                      ,body
                      (footer))))

            (define (language-index language)
              (define title
                (translate #$title language))

              (sxml-index
               language title
               `(main
                 (article
                  (@ (class "page centered-block limit-width"))
                  (h2 ,title)
                  (p (@ (class "post-metadata centered-text"))
                     #$version " — "
                     ,(seconds->string #$date language))

                  (div
                   (ul
                    (li (a (@ (href "html_node"))
                           "HTML, with a separate page per node"))
                    (li (a (@ (href
                               ,(string-append
                                 #$manual
                                 (if (string=? language
                                               "en")
                                     ""
                                     (string-append "."
                                                    language))
                                 ".html")))
                           "HTML, entirely on one page"))
                    ,@(if (member language '("ru" "zh_CN"))
                          '()
                          `((li (a (@ (href ,(string-append
                                              #$manual
                                              (if (string=? language "en")
                                                  ""
                                                  (string-append "."
                                                                 language))
                                              ".pdf"))))
                                "PDF")))))))))

            (define %iso639-languages
              (vector->list
               (assoc-ref (call-with-input-file
                              #+(file-append iso-codes
                                             "/share/iso-codes/json/iso_639-3.json")
                            json->scm)
                          "639-3")))

            (define (language-code->name code)
              "Return the full name of a language from its ISO-639-3 code."
              (let ((code (match (string-index code #\_)
                            (#f    code)
                            (index (string-take code index)))))
               (any (lambda (language)
                      (and (string=? (or (assoc-ref language "alpha_2")
                                         (assoc-ref language "alpha_3"))
                                     code)
                           (assoc-ref language "name")))
                    %iso639-languages)))

            (define (top-level-index languages)
              (define title #$title)
              (sxml-index
               "en" title
               `(main
                 (article
                  (@ (class "page centered-block limit-width"))
                  (h2 ,title)
                  (div
                   "This document is available in the following
languages:\n"
                   (ul
                    ,@(map (lambda (language)
                             `(li (a (@ (href ,(normalize language)))
                                     ,(translate
                                       (language-code->name language)
                                       language
                                       #:domain "iso_639-3"))))
                           languages)))))))

            (define (write-html file sxml)
              (call-with-output-file file
                (lambda (port)
                  (display "<!DOCTYPE html>\n" port)
                  (sxml->xml sxml port))))

            (setenv "GUIX_LOCPATH"
                    #+(file-append glibc-utf8-locales "/lib/locale"))
            (setenv "LC_ALL" "en_US.utf8")
            (setlocale LC_ALL "en_US.utf8")

            (for-each (lambda (language)
                        (define directory
                          (string-append #$output "/"
                                         (normalize language)))

                        (mkdir-p directory)
                        (write-html (string-append directory "/index.html")
                                    (language-index language)))
                      '#$languages)

            (write-html (string-append #$output "/index.html")
                        (top-level-index '#$languages))))))

  (computed-file "html-indexes" build))

(define* (pdf+html-manual source
                          #:key (languages %languages)
                          (version "0.0")
                          (date (time-second (current-time time-utc)))
                          (mono-node-indexes (map list %languages))
                          (split-node-indexes (map list %languages))
                          (manual %manual))
  "Return the union of the HTML and PDF manuals, as well as the indexes."
  (directory-union (string-append manual "-manual")
                   (map (lambda (proc)
                          (proc source
                                #:date date
                                #:languages languages
                                #:version version
                                #:manual manual))
                        (list html-manual-indexes
                              (lambda (source . args)
                                (apply html-manual source
                                       #:mono-node-indexes mono-node-indexes
                                       #:split-node-indexes split-node-indexes
                                       args))
                              pdf-manual))
                   #:copy? #t))

(define (latest-commit+date directory)
  "Return two values: the last commit ID (a hex string) for DIRECTORY, and its
commit date (an integer)."
  (let* ((repository (repository-open directory))
         (head       (repository-head repository))
         (oid        (reference-target head))
         (commit     (commit-lookup repository oid)))
    ;; TODO: Use (git describe) when it's widely available.
    (values (oid->string oid) (commit-time commit))))


;;;
;;; Guile manual.
;;;

(define guile-manual
  ;; The Guile manual as HTML, including both the mono-node "guile.html" and
  ;; the split-node "html_node" directory.
  (let ((guile guile-3.0-latest))
    (computed-file (string-append "guile-manual-" (package-version guile))
                   (with-imported-modules '((guix build utils))
                     #~(begin
                         (use-modules (guix build utils)
                                      (ice-9 match))

                         (setenv "PATH"
                                 (string-append #+tar "/bin:"
                                                #+xz "/bin:"
                                                #+texinfo "/bin"))
                         (invoke "tar" "xf" #$(package-source guile))
                         (mkdir-p (string-append #$output "/en/html_node"))

                         (let* ((texi (find-files "." "^guile\\.texi$"))
                                (documentation (match texi
                                                 ((file) (dirname file)))))
                           (with-directory-excursion documentation
                             (invoke "makeinfo" "--html" "--no-split"
                                     "-o" (string-append #$output
                                                         "/en/guile.html")
                                     "guile.texi")
                             (invoke "makeinfo" "--html" "-o" "split"
                                     "guile.texi")
                             (copy-recursively
                              "split"
                              (string-append #$output "/en/html_node")))))))))

(define %guile-manual-base-url
  "https://www.gnu.org/software/guile/manual")

(define (for-all-languages index)
  (map (lambda (language)
         (list language index))
       %languages))

(define guile-mono-node-indexes
  ;; The Guile manual is only available in English so use the same index in
  ;; all languages.
  (for-all-languages
   (html-manual-identifier-index (file-append guile-manual "/en")
                                 %guile-manual-base-url
                                 #:name "guile-html-index-en")))

(define guile-split-node-indexes
  (for-all-languages
   (html-manual-identifier-index (file-append guile-manual "/en/html_node")
                                 (string-append %guile-manual-base-url
                                                "/html_node")
                                 #:name "guile-html-index-en")))

(define (merge-index-alists alist1 alist2)
  "Merge ALIST1 and ALIST2, both of which are list of tuples like:

  (LANGUAGE INDEX1 INDEX2 ...)

where LANGUAGE is a string like \"en\" and INDEX1 etc. are indexes as returned
by 'html-identifier-indexes'."
  (let ((languages (delete-duplicates
                    (append (match alist1
                              (((languages . _) ...)
                               languages))
                            (match alist2
                              (((languages . _) ...)
                               languages))))))
    (map (lambda (language)
           (cons language
                 (append (or (assoc-ref alist1 language) '())
                         (or (assoc-ref alist2 language) '()))))
         languages)))


(let* ((root (canonicalize-path
              (string-append (current-source-directory) "/..")))
       (commit date (latest-commit+date root))
       (version (or (getenv "GUIX_MANUAL_VERSION")
                    (string-take commit 7)))
       (select? (let ((vcs? (git-predicate root)))
                  (lambda (file stat)
                    (and (vcs? file stat)
                         ;; Filter out this file.
                         (not (string=? (basename file) "build.scm"))))))
       (source (local-file root "guix" #:recursive? #t
                           #:select? select?)))

  (define guix-manual
    (html-manual source
                 #:manual "guix"
                 #:version version
                 #:date date))

  (define guix-mono-node-indexes
    ;; Alist of indexes for GUIX-MANUAL, where each key is a language code and
    ;; each value is a file-like object containing the identifier index.
    (html-identifier-indexes guix-manual ""
                             #:manual-name "guix"
                             #:base-url (if (string=? %manual "guix")
                                            (const "")
                                            (cut string-append
                                              "/manual/devel/" <>))
                             #:languages %languages))

  (define guix-split-node-indexes
    ;; Likewise for the split-node variant of GUIX-MANUAL.
    (html-identifier-indexes guix-manual "/html_node"
                             #:manual-name "guix"
                             #:base-url (if (string=? %manual "guix")
                                            (const "")
                                            (cut string-append
                                              "/manual/devel/" <>
                                              "/html_node"))
                             #:languages %languages))

  (define mono-node-indexes
    (merge-index-alists guix-mono-node-indexes guile-mono-node-indexes))

  (define split-node-indexes
    (merge-index-alists guix-split-node-indexes guile-split-node-indexes))

  (format (current-error-port)
          "building manual from work tree around commit ~a, ~a~%"
          commit
          (let* ((time (make-time time-utc 0 date))
                 (date (time-utc->date time)))
            (date->string date "~e ~B ~Y")))

  (pdf+html-manual source
                   ;; Always use the identifier indexes of GUIX-MANUAL and
                   ;; GUILE-MANUAL.  Both "guix" and "guix-cookbook" can
                   ;; contain links to definitions that appear in either of
                   ;; these two manuals.
                   #:mono-node-indexes mono-node-indexes
                   #:split-node-indexes split-node-indexes
                   #:version version
                   #:date date))