summaryrefslogtreecommitdiff
path: root/guix/transformations.scm
blob: 0976f0d824548774922b5aafa28dfcaac4f66a34 (about) (plain)
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
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2016-2022 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2021 Marius Bakke <marius@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 transformations)
  #:use-module ((guix config) #:select (%system))
  #:use-module (guix i18n)
  #:use-module (guix store)
  #:use-module (guix packages)
  #:use-module (guix build-system)
  #:use-module (guix profiles)
  #:use-module (guix diagnostics)
  #:autoload   (guix download) (download-to-store)
  #:autoload   (guix git-download) (git-reference? git-reference-url)
  #:autoload   (guix git) (git-checkout git-checkout? git-checkout-url)
  #:autoload   (guix upstream) (package-latest-release
                                upstream-source-version
                                upstream-source-signature-urls)
  #:autoload   (guix cpu) (current-cpu cpu->gcc-architecture)
  #:use-module (guix utils)
  #:use-module (guix memoization)
  #:use-module (guix gexp)

  ;; Use the procedure that destructures "NAME-VERSION" forms.
  #:use-module ((guix build utils)
                #:select ((package-name->name+version
                           . hyphen-package-name->name+version)))

  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-9)
  #:use-module (srfi srfi-11)
  #:use-module (srfi srfi-26)
  #:use-module (srfi srfi-34)
  #:use-module (srfi srfi-37)
  #:use-module (ice-9 match)
  #:use-module (ice-9 vlist)
  #:export (options->transformation
            manifest-entry-with-transformations

            tunable-package?
            tuned-package

            show-transformation-options-help
            transformation-option-key?
            %transformation-options))

;;; Commentary:
;;;
;;; This module implements "package transformation options"---tools for
;;; package graph rewriting.  It contains the graph rewriting logic, but also
;;; the tip of its user interface: command-line option handling.
;;;
;;; Code:

(module-autoload! (current-module) '(gnu packages)
                  '(specification->package))

(define (numeric-extension? file-name)
  "Return true if FILE-NAME ends with digits."
  (string-every char-set:hex-digit (file-extension file-name)))

(define (tarball-base-name file-name)
  "Return the \"base\" of FILE-NAME, removing '.tar.gz' or similar
extensions."
  ;; TODO: Factorize.
  (cond ((not (file-extension file-name))
         file-name)
        ((numeric-extension? file-name)
         file-name)
        ((string=? (file-extension file-name) "tar")
         (file-sans-extension file-name))
        ((file-extension file-name)
         =>
         (match-lambda
           ("scm" file-name)
           (_     (tarball-base-name (file-sans-extension file-name)))))
        (else
         file-name)))


;; Files to be downloaded.
(define-record-type <downloaded-file>
  (downloaded-file uri recursive?)
  downloaded-file?
  (uri        downloaded-file-uri)
  (recursive? downloaded-file-recursive?))

(define download-to-store*
  (store-lift download-to-store))

(define-gexp-compiler (compile-downloaded-file (file <downloaded-file>)
                                               system target)
  "Download FILE and return the result as a store item."
  (match file
    (($ <downloaded-file> uri recursive?)
     (download-to-store* uri #:recursive? recursive?))))

(define* (package-with-source p uri #:optional version)
  "Return a package based on P but with its source taken from URI.  Extract
the new package's version number from URI."
  (let ((base (tarball-base-name (basename uri))))
    (let-values (((_ version*)
                  (hyphen-package-name->name+version base)))
      (package (inherit p)
               (version (or version version*
                            (package-version p)))

               ;; Use #:recursive? #t to allow for directories.
               (source (downloaded-file uri #t))))))


;;;
;;; Transformations.
;;;

(define (transform-package-source sources)
  "Return a transformation procedure that replaces package sources with the
matching URIs given in SOURCES."
  (define new-sources
    (map (lambda (uri)
           (match (string-index uri #\=)
             (#f
              ;; Determine the package name and version from URI.
              (call-with-values
                  (lambda ()
                    (hyphen-package-name->name+version
                     (tarball-base-name (basename uri))))
                (lambda (name version)
                  (list name version uri))))
             (index
              ;; What's before INDEX is a "PKG@VER" or "PKG" spec.
              (call-with-values
                  (lambda ()
                    (package-name->name+version (string-take uri index)))
                (lambda (name version)
                  (list name version
                        (string-drop uri (+ 1 index))))))))
         sources))

  (lambda (obj)
    (let loop ((sources  new-sources)
               (result   '()))
      (match obj
        ((? package? p)
         (match (assoc-ref sources (package-name p))
           ((version source)
            (package-with-source p source version))
           (#f
            p)))
        (_
         obj)))))

(define (evaluate-replacement-specs specs proc)
  "Parse SPECS, a list of strings like \"guile=guile@2.1\" and return a list
of package spec/procedure pairs as expected by 'package-input-rewriting/spec'.
PROC is called with the package to be replaced and its replacement according
to SPECS.  Raise an error if an element of SPECS uses invalid syntax, or if a
package it refers to could not be found."
  (define not-equal
    (char-set-complement (char-set #\=)))

  (map (lambda (spec)
         (match (string-tokenize spec not-equal)
           ((spec new)
            (cons spec
                  (let ((new (specification->package new)))
                    (lambda (old)
                      (proc old new)))))
           (x
            (raise (formatted-message
                    (G_ "invalid replacement specification: ~s")
                    spec)))))
       specs))

(define (transform-package-inputs replacement-specs)
  "Return a procedure that, when passed a package, replaces its direct
dependencies according to REPLACEMENT-SPECS.  REPLACEMENT-SPECS is a list of
strings like \"guile=guile@2.1\" meaning that, any dependency on a package
called \"guile\" must be replaced with a dependency on a version 2.1 of
\"guile\"."
  (let* ((replacements (evaluate-replacement-specs replacement-specs
                                                   (lambda (old new)
                                                     new)))
         (rewrite      (package-input-rewriting/spec replacements)))
    (lambda (obj)
      (if (package? obj)
          (rewrite obj)
          obj))))

(define (transform-package-inputs/graft replacement-specs)
  "Return a procedure that, when passed a package, replaces its direct
dependencies according to REPLACEMENT-SPECS.  REPLACEMENT-SPECS is a list of
strings like \"gnutls=gnutls@3.5.4\" meaning that packages are built using the
current 'gnutls' package, after which version 3.5.4 is grafted onto them."
  (define (set-replacement old new)
    (package (inherit old) (replacement new)))

  (let* ((replacements (evaluate-replacement-specs replacement-specs
                                                   set-replacement))
         (rewrite      (package-input-rewriting/spec replacements)))
    (lambda (obj)
      (if (package? obj)
          (rewrite obj)
          obj))))

(define %not-equal
  (char-set-complement (char-set #\=)))

(define (package-git-url package)
  "Return the URL of the Git repository for package, or raise an error if
the source of PACKAGE is not fetched from a Git repository."
  (let ((source (package-source package)))
    (cond ((and (origin? source)
                (git-reference? (origin-uri source)))
           (git-reference-url (origin-uri source)))
          ((git-checkout? source)
           (git-checkout-url source))
          (else
           (raise
            (formatted-message (G_ "the source of ~a is not a Git reference")
                               (package-full-name package)))))))

(define (evaluate-git-replacement-specs specs proc)
  "Parse SPECS, a list of strings like \"guile=stable-2.2\", and return a list
of package pairs, where (PROC PACKAGE URL BRANCH-OR-COMMIT) returns the
replacement package.  Raise an error if an element of SPECS uses invalid
syntax, or if a package it refers to could not be found."
  (map (lambda (spec)
         (match (string-tokenize spec %not-equal)
           ((spec branch-or-commit)
            (define (replace old)
              (let* ((source (package-source old))
                     (url    (package-git-url old)))
                (proc old url branch-or-commit)))

            (cons spec replace))
           (_
            (raise
             (formatted-message (G_ "invalid replacement specification: ~s")
                                spec)))))
       specs))

(define (transform-package-source-branch replacement-specs)
  "Return a procedure that, when passed a package, replaces its direct
dependencies according to REPLACEMENT-SPECS.  REPLACEMENT-SPECS is a list of
strings like \"guile-next=stable-3.0\" meaning that packages are built using
'guile-next' from the latest commit on its 'stable-3.0' branch."
  (define (replace old url branch)
    (package
      (inherit old)
      (version (string-append "git." (string-map (match-lambda
                                                   (#\/ #\-)
                                                   (chr chr))
                                                 branch)))
      (source (git-checkout (url url) (branch branch)
                            (recursive? #t)))))

  (let* ((replacements (evaluate-git-replacement-specs replacement-specs
                                                       replace))
         (rewrite      (package-input-rewriting/spec replacements)))
    (lambda (obj)
      (if (package? obj)
          (rewrite obj)
          obj))))

(define (commit->version-string commit)
  "Return a string suitable for use in the 'version' field of a package based
on the given COMMIT."
  (cond ((and (> (string-length commit) 1)
              (string-prefix? "v" commit)
              (char-set-contains? char-set:digit
                                  (string-ref commit 1)))
         ;; Probably a tag like "v1.0" or a 'git describe' identifier.
         (string-drop commit 1))
        ((not (string-every char-set:hex-digit commit))
         ;; Pass through tags and 'git describe' style IDs directly.
         commit)
        (else
         (string-append "git."
                        (if (< (string-length commit) 7)
                            commit
                            (string-take commit 7))))))


(define (transform-package-source-commit replacement-specs)
  "Return a procedure that, when passed a package, replaces its direct
dependencies according to REPLACEMENT-SPECS.  REPLACEMENT-SPECS is a list of
strings like \"guile-next=cabba9e\" meaning that packages are built using
'guile-next' from commit 'cabba9e'."
  (define (replace old url commit)
    (package
      (inherit old)
      (version (commit->version-string commit))
      (source (git-checkout (url url) (commit commit)
                            (recursive? #t)))))

  (let* ((replacements (evaluate-git-replacement-specs replacement-specs
                                                       replace))
         (rewrite      (package-input-rewriting/spec replacements)))
    (lambda (obj)
      (if (package? obj)
          (rewrite obj)
          obj))))

(define (transform-package-source-git-url replacement-specs)
  "Return a procedure that, when passed a package, replaces its dependencies
according to REPLACEMENT-SPECS.  REPLACEMENT-SPECS is a list of strings like
\"guile-json=https://gitthing.com/…\" meaning that packages are built using
a checkout of the Git repository at the given URL."
  (define replacements
    (map (lambda (spec)
           (match (string-tokenize spec %not-equal)
             ((spec url)
              (cons spec
                    (lambda (old)
                      (package
                        (inherit old)
                        (source (git-checkout (url url)
                                              (recursive? #t)))))))
             (_
              (raise
               (formatted-message
                (G_ "~a: invalid Git URL replacement specification")
                spec)))))
         replacement-specs))

  (define rewrite
    (package-input-rewriting/spec replacements))

  (lambda (obj)
    (if (package? obj)
        (rewrite obj)
        obj)))

(define (package-dependents/spec top bottom)
  "Return the list of dependents of BOTTOM, a spec string, that are also
dependencies of TOP, a package."
  (define-values (name version)
    (package-name->name+version bottom))

  (define dependent?
    (mlambda (p)
      (and (package? p)
           (or (and (string=? name (package-name p))
                    (or (not version)
                        (version-prefix? version (package-version p))))
               (match (bag-direct-inputs (package->bag p))
                 (((labels dependencies . _) ...)
                  (any dependent? dependencies)))))))

  (filter dependent? (package-closure (list top))))

(define (package-toolchain-rewriting p bottom toolchain)
  "Return a procedure that, when passed a package that's either BOTTOM or one
of its dependents up to P so, changes it so it is built with TOOLCHAIN.
TOOLCHAIN must be an input list."
  (define rewriting-property
    (gensym " package-toolchain-rewriting"))

  (match (package-dependents/spec p bottom)
    (()                                           ;P does not depend on BOTTOM
     identity)
    (set
     ;; SET is the list of packages "between" P and BOTTOM (included) whose
     ;; toolchain needs to be changed.
     (package-mapping (lambda (p)
                        (if (or (assq rewriting-property
                                      (package-properties p))
                                (not (memq p set)))
                            p
                            (let ((p (package-with-c-toolchain p toolchain)))
                              (package/inherit p
                                (properties `((,rewriting-property . #t)
                                              ,@(package-properties p)))))))
                      (lambda (p)
                        (or (assq rewriting-property (package-properties p))
                            (not (memq p set))))
                      #:deep? #t))))

(define (transform-package-toolchain replacement-specs)
  "Return a procedure that, when passed a package, changes its toolchain or
that of its dependencies according to REPLACEMENT-SPECS.  REPLACEMENT-SPECS is
a list of strings like \"fftw=gcc-toolchain@10\" meaning that the package to
the left of the equal sign must be built with the toolchain to the right of
the equal sign."
  (define split-on-commas
    (cute string-tokenize <> (char-set-complement (char-set #\,))))

  (define (specification->input spec)
    (let ((package (specification->package spec)))
      (list (package-name package) package)))

  (define replacements
    (map (lambda (spec)
           (match (string-tokenize spec %not-equal)
             ((spec (= split-on-commas toolchain))
              (cons spec (map specification->input toolchain)))
             (_
              (raise
               (formatted-message
                (G_ "~a: invalid toolchain replacement specification")
                spec)))))
         replacement-specs))

  (lambda (obj)
    (if (package? obj)
        (or (any (match-lambda
                   ((bottom . toolchain)
                    ((package-toolchain-rewriting obj bottom toolchain) obj)))
                 replacements)
            obj)
        obj)))

(define tuning-compiler
  (mlambda (micro-architecture)
    "Return a compiler wrapper that passes '-march=MICRO-ARCHITECTURE' to the
actual compiler."
    (define wrapper
      #~(begin
          (use-modules (ice-9 match))

          (define* (search-next command
                                #:optional
                                (path (string-split (getenv "PATH")
                                                    #\:)))
            ;; Search the next COMMAND on PATH, a list of
            ;; directories representing the executable search path.
            (define this
              (stat (car (command-line))))

            (let loop ((path path))
              (match path
                (()
                 (match command
                   ("cc" (search-next "gcc"))
                   (_ #f)))
                ((directory rest ...)
                 (let* ((file (string-append
                               directory "/" command))
                        (st   (stat file #f)))
                   (if (and st (not (equal? this st)))
                       file
                       (loop rest)))))))

          (match (command-line)
            ((command arguments ...)
             (match (search-next (basename command))
               (#f (exit 127))
               (next
                (apply execl next
                       (append (cons next arguments)
                           (list (string-append "-march="
                                                #$micro-architecture))))))))))

    (define program
      (program-file (string-append "tuning-compiler-wrapper-" micro-architecture)
                    wrapper))

    (computed-file (string-append "tuning-compiler-" micro-architecture)
                   (with-imported-modules '((guix build utils))
                     #~(begin
                         (use-modules (guix build utils))

                         (define bin (string-append #$output "/bin"))
                         (mkdir-p bin)

                         (for-each (lambda (program)
                                     (symlink #$program
                                              (string-append bin "/" program)))
                                   '("cc" "gcc" "clang" "g++" "c++" "clang++")))))))

(define (build-system-with-tuning-compiler bs micro-architecture)
  "Return a variant of BS, a build system, that ensures that the compiler that
BS uses (usually an implicit input) can generate code for MICRO-ARCHITECTURE,
which names a specific CPU of the target architecture--e.g., when targeting
86_64 MICRO-ARCHITECTURE might be \"skylake\".  If it does, return a build
system that builds code for MICRO-ARCHITECTURE; otherwise raise an error."
  (define %not-hyphen
    (char-set-complement (char-set #\-)))

  (define lower
    (build-system-lower bs))

  (define (lower* . args)
    ;; The list of CPU names supported by the '-march' option of C/C++
    ;; compilers is specific to each compiler and version thereof.  Rather
    ;; than pass '-march=MICRO-ARCHITECTURE' as is to the compiler, possibly
    ;; leading to an obscure build error, check whether the compiler is known
    ;; to support MICRO-ARCHITECTURE.  If not, bail out.
    (let* ((lowered      (apply lower args))
           (architecture (match (string-tokenize (bag-system lowered)
                                                 %not-hyphen)
                           ((arch _ ...) arch)))
           (compiler     (any (match-lambda
                                ((label (? package? p) . _)
                                 (and (assoc-ref (package-properties p)
                                                 'compiler-cpu-architectures)
                                      p))
                                (_ #f))
                              (bag-build-inputs lowered))))
      (unless compiler
        (raise (formatted-message
                (G_ "failed to determine which compiler is used"))))

      (let ((lst (assoc-ref (package-properties compiler)
                            'compiler-cpu-architectures)))
        (unless lst
          (raise (formatted-message
                  (G_ "failed to determine whether ~a supports ~a")
                  (package-full-name compiler)
                  micro-architecture)))
        (unless (member micro-architecture
                        (or (assoc-ref lst architecture) '()))
          (raise (formatted-message
                  (G_ "compiler ~a does not support micro-architecture ~a")
                  (package-full-name compiler)
                  micro-architecture))))

      (bag
        (inherit lowered)
        (build-inputs
         ;; Arrange so that the compiler wrapper comes first in $PATH.
         `(("tuning-compiler" ,(tuning-compiler micro-architecture))
           ,@(bag-build-inputs lowered))))))

  (build-system
    (inherit bs)
    (lower lower*)))

(define (tuned-package p micro-architecture)
  "Return package P tuned for MICRO-ARCHITECTURE."
  (package
    (inherit p)
    (build-system
      (build-system-with-tuning-compiler (package-build-system p)
                                         micro-architecture))
    (arguments
     ;; The machine building this package may or may not be able to run code
     ;; for MICRO-ARCHITECTURE.  Because of that, skip tests; they are run for
     ;; the "baseline" variant anyway.
     (substitute-keyword-arguments (package-arguments p)
       ((#:tests? _ #f) #f)))

    (properties
     `((cpu-tuning . ,micro-architecture)

       ;; Remove the 'tunable?' property so that 'package-tuning' does not
       ;; call 'tuned-package' again on this one.
       ,@(alist-delete 'tunable? (package-properties p))))))

(define (tunable-package? package)
  "Return true if package PACKAGE is \"tunable\"--i.e., if tuning it for the
host CPU is worthwhile."
  (assq 'tunable? (package-properties package)))

(define package-tuning
  (mlambda (micro-architecture)
    "Return a procedure that maps the given package to its counterpart tuned
for MICRO-ARCHITECTURE, a string suitable for GCC's '-march'."
    (define rewriting-property
      (gensym " package-tuning"))

    (package-mapping (lambda (p)
                       (cond ((assq rewriting-property (package-properties p))
                              p)
                             ((assq 'tunable? (package-properties p))
                              (info (G_ "tuning ~a for CPU ~a~%")
                                    (package-full-name p) micro-architecture)
                              (package/inherit p
                                (replacement (tuned-package p micro-architecture))
                                (properties `((,rewriting-property . #t)
                                              ,@(package-properties p)))))
                             (else
                              p)))
                     (lambda (p)
                       (assq rewriting-property (package-properties p)))
                     #:deep? #t)))

(define (transform-package-tuning micro-architectures)
  "Return a procedure that, when "
  (match micro-architectures
    ((micro-architecture _ ...)
     (let ((rewrite (package-tuning micro-architecture)))
       (lambda (obj)
         (if (package? obj)
             (rewrite obj)
             obj))))))

(define (transform-package-with-debug-info specs)
  "Return a procedure that, when passed a package, set its 'replacement' field
to the same package but with #:strip-binaries? #f in its 'arguments' field."
  (define (non-stripped p)
    (package
      (inherit p)
      (arguments
       (substitute-keyword-arguments (package-arguments p)
         ((#:strip-binaries? _ #f) #f)))))

  (define (package-with-debug-info p)
    (if (member "debug" (package-outputs p))
        p
        (let loop ((p p))
          (match (package-replacement p)
            (#f
             (package
               (inherit p)
               (replacement (non-stripped p))))
            (next
             (package
               (inherit p)
               (replacement (loop next))))))))

  (define rewrite
    (package-input-rewriting/spec (map (lambda (spec)
                                         (cons spec package-with-debug-info))
                                       specs)))

  (lambda (obj)
    (if (package? obj)
        (rewrite obj)
        obj)))

(define (transform-package-tests specs)
  "Return a procedure that, when passed a package, sets #:tests? #f in its
'arguments' field."
  (define (package-without-tests p)
    (package/inherit p
      (arguments
       (substitute-keyword-arguments (package-arguments p)
         ((#:tests? _ #f) #f)))))

  (define rewrite
    (package-input-rewriting/spec (map (lambda (spec)
                                         (cons spec package-without-tests))
                                       specs)))

  (lambda (obj)
    (if (package? obj)
        (rewrite obj)
        obj)))

(define (patched-source name source patches)
  "Return a file-like object with the given NAME that applies PATCHES to
SOURCE.  SOURCE must itself be a file-like object of any type, including
<git-checkout>, <local-file>, etc."
  (define patch
    (module-ref (resolve-interface '(gnu packages base)) 'patch))

  (computed-file name
                 (with-imported-modules '((guix build utils))
                   #~(begin
                       (use-modules (guix build utils))

                       (setenv "PATH" #+(file-append patch "/bin"))

                       ;; XXX: Assume SOURCE is a directory.  This is true in
                       ;; most practical cases, where it's a <git-checkout>.
                       (copy-recursively #+source #$output)
                       (chdir #$output)
                       (for-each (lambda (patch)
                                   (invoke "patch" "-p1" "--batch"
                                           "-i" patch))
                                 '(#+@patches))))))

(define (transform-package-patches specs)
  "Return a procedure that, when passed a package, returns a package with
additional patches."
  (define (package-with-extra-patches p patches)
    (let ((patches (map (lambda (file)
                          (local-file file))
                        patches)))
      (if (origin? (package-source p))
          (package/inherit p
            (source (origin
                      (inherit (package-source p))
                      (patches (append patches
                                       (origin-patches (package-source p)))))))
          (package/inherit p
            (source (patched-source (string-append (package-full-name p "-")
                                                   "-source")
                                    (package-source p) patches))))))

  (define (coalesce-alist alist)
    ;; Coalesce multiple occurrences of the same key in ALIST.
    (let loop ((alist alist)
               (keys '())
               (mapping vlist-null))
      (match alist
        (()
         (map (lambda (key)
                (cons key (vhash-fold* cons '() key mapping)))
              (delete-duplicates (reverse keys))))
        (((key . value) . rest)
         (loop rest
               (cons key keys)
               (vhash-cons key value mapping))))))

  (define patches
    ;; Spec/patch alist.
    (coalesce-alist
     (map (lambda (spec)
            (match (string-tokenize spec %not-equal)
              ((spec patch)
               (cons spec (canonicalize-path patch)))
              (_
               (raise (formatted-message
                       (G_ "~a: invalid package patch specification")
                       spec)))))
          specs)))

  (define rewrite
    (package-input-rewriting/spec
     (map (match-lambda
            ((spec . patches)
             (cons spec (cut package-with-extra-patches <> patches))))
          patches)))

  (lambda (obj)
    (if (package? obj)
        (rewrite obj)
        obj)))

(define (transform-package-latest specs)
  "Return a procedure that rewrites package graphs such that those in SPECS
are replaced by their latest upstream version."
  (define (package-with-latest-upstream p)
    (let ((source (package-latest-release p)))
      (cond ((not source)
             (warning
              (G_ "could not determine latest upstream release of '~a'~%")
              (package-name p))
             p)
            ((string=? (upstream-source-version source)
                       (package-version p))
             p)
            (else
             (unless (pair? (upstream-source-signature-urls source))
               (warning (G_ "cannot authenticate source of '~a', version ~a~%")
                        (package-name p)
                        (upstream-source-version source)))

             ;; TODO: Take 'upstream-source-input-changes' into account.
             (package
               (inherit p)
               (version (upstream-source-version source))
               (source source))))))

  (define rewrite
    (package-input-rewriting/spec
     (map (lambda (spec)
            (cons spec package-with-latest-upstream))
          specs)))

  (lambda (obj)
    (if (package? obj)
        (rewrite obj)
        obj)))

(define %transformations
  ;; Transformations that can be applied to things to build.  The car is the
  ;; key used in the option alist, and the cdr is the transformation
  ;; procedure; it is called with two arguments: the store, and a list of
  ;; things to build.
  `((with-source . ,transform-package-source)
    (with-input  . ,transform-package-inputs)
    (with-graft  . ,transform-package-inputs/graft)
    (with-branch . ,transform-package-source-branch)
    (with-commit . ,transform-package-source-commit)
    (with-git-url . ,transform-package-source-git-url)
    (with-c-toolchain . ,transform-package-toolchain)
    (tune . ,transform-package-tuning)
    (with-debug-info . ,transform-package-with-debug-info)
    (without-tests . ,transform-package-tests)
    (with-patch  . ,transform-package-patches)
    (with-latest . ,transform-package-latest)))

(define (transformation-procedure key)
  "Return the transformation procedure associated with KEY, a symbol such as
'with-source', or #f if there is none."
  (any (match-lambda
         ((k . proc)
          (and (eq? k key) proc)))
       %transformations))

(define (transformation-option-key? key)
  "Return true if KEY is an option key (as returned while parsing options with
%TRANSFORMATION-OPTIONS) corresponding to a package transformation option.
For example, (transformation-option-key? 'with-input) => #t."
  (->bool (transformation-procedure key)))


;;;
;;; Command-line handling.
;;;

(define %transformation-options
  ;; The command-line interface to the above transformations.
  (let ((parser (lambda (symbol)
                  (lambda (opt name arg result . rest)
                    (apply values
                           (alist-cons symbol arg result)
                           rest)))))
    (list (option '("with-source") #t #f
                  (parser 'with-source))
          (option '("with-input") #t #f
                  (parser 'with-input))
          (option '("with-graft") #t #f
                  (parser 'with-graft))
          (option '("with-branch") #t #f
                  (parser 'with-branch))
          (option '("with-commit") #t #f
                  (parser 'with-commit))
          (option '("with-git-url") #t #f
                  (parser 'with-git-url))
          (option '("with-c-toolchain") #t #f
                  (parser 'with-c-toolchain))
          (option '("tune") #f #t
                  (lambda (opt name arg result . rest)
                    (define micro-architecture
                      (match arg
                        ((or #f "native")
                         (unless (string=? (or (assoc-ref result 'system)
                                               (%current-system))
                                           %system)
                           (leave (G_ "\
building for ~a instead of ~a, so tuning cannot be guessed~%")
                                  (assoc-ref result 'system) %system))

                         (cpu->gcc-architecture (current-cpu)))
                        ("generic" #f)
                        (_ arg)))

                    (apply values
                           (if micro-architecture
                               (alist-cons 'tune micro-architecture
                                           result)
                               (alist-delete 'tune result))
                           rest)))
          (option '("with-debug-info") #t #f
                  (parser 'with-debug-info))
          (option '("without-tests") #t #f
                  (parser 'without-tests))
          (option '("with-patch") #t #f
                  (parser 'with-patch))
          (option '("with-latest") #t #f
                  (parser 'with-latest))

          (option '("help-transform") #f #f
                  (lambda _
                    (format #t
                            (G_ "Available package transformation options:~%"))
                    (show-transformation-options-help/detailed)
                    (newline)
                    (exit 0))))))

(define (show-transformation-options-help/detailed)
  (display (G_ "
      --with-source=[PACKAGE=]SOURCE
                         use SOURCE when building the corresponding package"))
  (display (G_ "
      --with-input=PACKAGE=REPLACEMENT
                         replace dependency PACKAGE by REPLACEMENT"))
  (display (G_ "
      --with-graft=PACKAGE=REPLACEMENT
                         graft REPLACEMENT on packages that refer to PACKAGE"))
  (display (G_ "
      --with-branch=PACKAGE=BRANCH
                         build PACKAGE from the latest commit of BRANCH"))
  (display (G_ "
      --with-commit=PACKAGE=COMMIT
                         build PACKAGE from COMMIT"))
  (display (G_ "
      --with-git-url=PACKAGE=URL
                         build PACKAGE from the repository at URL"))
  (display (G_ "
      --with-patch=PACKAGE=FILE
                         add FILE to the list of patches of PACKAGE"))
  (display (G_ "
      --with-latest=PACKAGE
                         use the latest upstream release of PACKAGE"))
  (display (G_ "
      --with-c-toolchain=PACKAGE=TOOLCHAIN
                         build PACKAGE and its dependents with TOOLCHAIN"))
  (display (G_ "
      --with-debug-info=PACKAGE
                         build PACKAGE and preserve its debug info"))
  (display (G_ "
      --without-tests=PACKAGE
                         build PACKAGE without running its tests")))

(define (show-transformation-options-help)
  "Show basic help for package transformation options."
  (display (G_ "
      --help-transform   list package transformation options not shown here")))

(define (options->transformation opts)
  "Return a procedure that, when passed an object to build (package,
derivation, etc.), applies the transformations specified by OPTS and returns
the resulting objects.  OPTS must be a list of symbol/string pairs such as:

  ((with-branch . \"guile-gcrypt=master\")
   (without-tests . \"libgcrypt\"))

Each symbol names a transformation and the corresponding string is an argument
to that transformation."
  (define applicable
    ;; List of applicable transformations as symbol/procedure pairs in the
    ;; order in which they appear on the command line.
    (filter-map (match-lambda
                  ((key . value)
                   (match (transformation-procedure key)
                     (#f
                      #f)
                     (transform
                      ;; XXX: We used to pass TRANSFORM a list of several
                      ;; arguments, but we now pass only one, assuming that
                      ;; transform composes well.
                      (list key value (transform (list value)))))))
                (reverse opts)))

  (define (package-with-transformation-properties p)
    (package/inherit p
      (properties `((transformations
                     . ,(map (match-lambda
                               ((key value _)
                                (cons key value)))
                             applicable))
                    ,@(package-properties p)))))

  (lambda (obj)
    (define (tagged-object new)
      (if (and (not (eq? obj new))
               (package? new) (not (null? applicable)))
          (package-with-transformation-properties new)
          new))

    (tagged-object
     (fold (match-lambda*
             (((name value transform) obj)
              (let ((new (transform obj)))
                (when (eq? new obj)
                  (warning (G_ "transformation '~a' had no effect on ~a~%")
                           name
                           (if (package? obj)
                               (package-full-name obj)
                               obj)))
                new)))
           obj
           applicable))))

(define (package-transformations package)
  "Return the transformations applied to PACKAGE according to its properties."
  (match (assq-ref (package-properties package) 'transformations)
    (#f '())
    (transformations transformations)))

(define (manifest-entry-with-transformations entry)
  "Return ENTRY with an additional 'transformations' property if it's not
already there."
  (let ((properties (manifest-entry-properties entry)))
    (if (assq 'transformations properties)
        entry
        (let ((item (manifest-entry-item entry)))
          (manifest-entry
            (inherit entry)
            (properties
             (match (and (package? item)
                         (package-transformations item))
               ((or #f '())
                properties)
               (transformations
                `((transformations . ,transformations)
                  ,@properties)))))))))