guix/grafts.scm

   1 ;;; GNU Guix --- Functional package management for GNU
   2 ;;; Copyright © 2014, 2015, 2016, 2017, 2018, 2019 Ludovic Courtès <ludo@gnu.org>
   3 ;;;
   4 ;;; This file is part of GNU Guix.
   5 ;;;
   6 ;;; GNU Guix is free software; you can redistribute it and/or modify it
   7 ;;; under the terms of the GNU General Public License as published by
   8 ;;; the Free Software Foundation; either version 3 of the License, or (at
   9 ;;; your option) any later version.
  10 ;;;
  11 ;;; GNU Guix is distributed in the hope that it will be useful, but
  12 ;;; WITHOUT ANY WARRANTY; without even the implied warranty of
  13 ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 ;;; GNU General Public License for more details.
  15 ;;;
  16 ;;; You should have received a copy of the GNU General Public License
  17 ;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
  18
  19 (define-module (guix grafts)
  20   #:use-module (guix store)
  21   #:use-module (guix monads)
  22   #:use-module (guix records)
  23   #:use-module (guix derivations)
  24   #:use-module ((guix utils) #:select (%current-system))
  25   #:use-module (guix sets)
  26   #:use-module (srfi srfi-1)
  27   #:use-module (srfi srfi-9 gnu)
  28   #:use-module (srfi srfi-26)
  29   #:use-module (srfi srfi-34)
  30   #:use-module (ice-9 match)
  31   #:use-module (ice-9 vlist)
  32   #:export (graft?
  33             graft
  34             graft-origin
  35             graft-replacement
  36             graft-origin-output
  37             graft-replacement-output
  38
  39             graft-derivation
  40             graft-derivation/shallow
  41
  42             %graft?
  43             set-grafting
  44             grafting?))
  45
  46 (define-record-type* <graft> graft make-graft
  47   graft?
  48   (origin             graft-origin)               ;derivation | store item
  49   (origin-output      graft-origin-output         ;string | #f
  50                       (default "out"))
  51   (replacement        graft-replacement)          ;derivation | store item
  52   (replacement-output graft-replacement-output    ;string | #f
  53                       (default "out")))
  54
  55 (define (write-graft graft port)
  56   "Write a concise representation of GRAFT to PORT."
  57   (define (->string thing output)
  58     (if (derivation? thing)
  59         (derivation->output-path thing output)
  60         thing))
  61
  62   (match graft
  63     (($ <graft> origin origin-output replacement replacement-output)
  64      (format port "#<graft ~a ==> ~a ~a>"
  65              (->string origin origin-output)
  66              (->string replacement replacement-output)
  67              (number->string (object-address graft) 16)))))
  68
  69 (set-record-type-printer! <graft> write-graft)
  70
  71 (define (graft-origin-file-name graft)
  72   "Return the output file name of the origin of GRAFT."
  73   (match graft
  74     (($ <graft> (? derivation? origin) output)
  75      (derivation->output-path origin output))
  76     (($ <graft> (? string? item))
  77      item)))
  78
  79 (define* (graft-derivation/shallow store drv grafts
  80                                    #:key
  81                                    (name (derivation-name drv))
  82                                    (outputs (derivation-output-names drv))
  83                                    (guile (%guile-for-build))
  84                                    (system (%current-system)))
  85   "Return a derivation called NAME, which applies GRAFTS to the specified
  86 OUTPUTS of DRV.  This procedure performs \"shallow\" grafting in that GRAFTS
  87 are not recursively applied to dependencies of DRV."
  88   ;; XXX: Someday rewrite using gexps.
  89   (define mapping
  90     ;; List of store item pairs.
  91     (map (match-lambda
  92           (($ <graft> source source-output target target-output)
  93            (cons (if (derivation? source)
  94                      (derivation->output-path source source-output)
  95                      source)
  96                  (if (derivation? target)
  97                      (derivation->output-path target target-output)
  98                      target))))
  99          grafts))
 100
 101   (define output-pairs
 102     (map (lambda (output)
 103            (cons output
 104                  (derivation-output-path
 105                   (assoc-ref (derivation-outputs drv) output))))
 106          outputs))
 107
 108   (define build
 109     `(begin
 110        (use-modules (guix build graft)
 111                     (guix build utils)
 112                     (ice-9 match))
 113
 114        (let* ((old-outputs ',output-pairs)
 115               (mapping (append ',mapping
 116                                (map (match-lambda
 117                                       ((name . file)
 118                                        (cons (assoc-ref old-outputs name)
 119                                              file)))
 120                                     %outputs))))
 121          (graft old-outputs %outputs mapping))))
 122
 123   (define add-label
 124     (cut cons "x" <>))
 125
 126   (define properties
 127     `((type . graft)
 128       (graft (count . ,(length grafts)))))
 129
 130   (match grafts
 131     ((($ <graft> sources source-outputs targets target-outputs) ...)
 132      (let ((sources (zip sources source-outputs))
 133            (targets (zip targets target-outputs)))
 134        (build-expression->derivation store name build
 135                                      #:system system
 136                                      #:guile-for-build guile
 137                                      #:modules '((guix build graft)
 138                                                  (guix build utils)
 139                                                  (guix build debug-link)
 140                                                  (guix elf))
 141                                      #:inputs `(,@(map (lambda (out)
 142                                                          `("x" ,drv ,out))
 143                                                        outputs)
 144                                                 ,@(append (map add-label sources)
 145                                                           (map add-label targets)))
 146                                      #:outputs outputs
 147
 148                                      ;; Grafts are computationally cheap so no
 149                                      ;; need to offload or substitute.
 150                                      #:local-build? #t
 151                                      #:substitutable? #f
 152
 153                                      #:properties properties)))))
 154
 155 (define (non-self-references references drv outputs)
 156   "Return the list of references of the OUTPUTS of DRV, excluding self
 157 references.  Call REFERENCES to get the list of references."
 158   (let ((refs (append-map (compose references
 159                                    (cut derivation->output-path drv <>))
 160                           outputs))
 161         (self (match (derivation->output-paths drv)
 162                 (((names . items) ...)
 163                  items))))
 164     (remove (cut member <> self) refs)))
 165
 166 (define (references-oracle store input)
 167   "Return a one-argument procedure that, when passed the output file names of
 168 INPUT, a derivation input, or their dependencies, returns the list of
 169 references of that item.  Use either local info or substitute info; build
 170 INPUT if no information is available."
 171   (define (references* items)
 172     (guard (c ((store-protocol-error? c)
 173                ;; As a last resort, build DRV and query the references of the
 174                ;; build result.
 175
 176                ;; Warm up the narinfo cache, otherwise each derivation build
 177                ;; will result in one HTTP request to get one narinfo, which is
 178                ;; much less efficient than fetching them all upfront.
 179                (substitution-oracle store
 180                                     (list (derivation-input-derivation input)))
 181
 182                (and (build-derivations store (list input))
 183                     (map (cut references store <>) items))))
 184       (references/substitutes store items)))
 185
 186   (let loop ((items (derivation-input-output-paths input))
 187              (result vlist-null))
 188     (match items
 189       (()
 190        (lambda (item)
 191          (match (vhash-assoc item result)
 192            ((_ . refs) refs)
 193            (#f         #f))))
 194       (_
 195        (let* ((refs   (references* items))
 196               (result (fold vhash-cons result items refs)))
 197          (loop (remove (cut vhash-assoc <> result)
 198                        (delete-duplicates (concatenate refs) string=?))
 199                result))))))
 200
 201 (define-syntax-rule (with-cache key exp ...)
 202   "Cache the value of monadic expression EXP under KEY."
 203   (mlet %state-monad ((cache (current-state)))
 204     (match (vhash-assoc key cache)
 205       ((_ . result)                               ;cache hit
 206        (return result))
 207       (#f                                         ;cache miss
 208        (mlet %state-monad ((result (begin exp ...))
 209                            (cache  (current-state)))
 210          (mbegin %state-monad
 211            (set-current-state (vhash-cons key result cache))
 212            (return result)))))))
 213
 214 (define (reference-origin drv item)
 215   "Return the derivation/output pair among the inputs of DRV, recursively,
 216 that produces ITEM.  Return #f if ITEM is not produced by a derivation (i.e.,
 217 it's a content-addressed \"source\"), or if it's not produced by a dependency
 218 of DRV."
 219   ;; Perform a breadth-first traversal of the dependency graph of DRV in
 220   ;; search of the derivation that produces ITEM.
 221   (let loop ((drv (list drv))
 222              (visited (setq)))
 223     (match drv
 224       (()
 225        #f)
 226       ((drv . rest)
 227        (if (set-contains? visited drv)
 228            (loop rest visited)
 229            (let ((inputs (derivation-inputs drv)))
 230              (or (any (lambda (input)
 231                         (let ((drv (derivation-input-derivation input)))
 232                           (any (match-lambda
 233                                  ((output . file)
 234                                   (and (string=? file item)
 235                                        (cons drv output))))
 236                                (derivation->output-paths drv))))
 237                       inputs)
 238                  (loop (append rest (map derivation-input-derivation inputs))
 239                        (set-insert drv visited)))))))))
 240
 241 (define* (cumulative-grafts store drv grafts
 242                             references
 243                             #:key
 244                             (outputs (derivation-output-names drv))
 245                             (guile (%guile-for-build))
 246                             (system (%current-system)))
 247   "Augment GRAFTS with additional grafts resulting from the application of
 248 GRAFTS to the dependencies of DRV; REFERENCES must be a one-argument procedure
 249 that returns the list of references of the store item it is given.  Return the
 250 resulting list of grafts.
 251
 252 This is a monadic procedure in %STATE-MONAD where the state is a vhash mapping
 253 derivations to the corresponding set of grafts."
 254   (define (graft-origin? drv graft)
 255     ;; Return true if DRV corresponds to the origin of GRAFT.
 256     (match graft
 257       (($ <graft> (? derivation? origin) output)
 258        (match (assoc-ref (derivation->output-paths drv) output)
 259          ((? string? result)
 260           (string=? result
 261                     (derivation->output-path origin output)))
 262          (_
 263           #f)))
 264       (_
 265        #f)))
 266
 267   (define (dependency-grafts item)
 268     (match (reference-origin drv item)
 269       ((drv . output)
 270        ;; If GRAFTS already contains a graft from DRV, do not override it.
 271        (if (find (cut graft-origin? drv <>) grafts)
 272            (state-return grafts)
 273            (cumulative-grafts store drv grafts references
 274                               #:outputs (list output)
 275                               #:guile guile
 276                               #:system system)))
 277       (#f
 278        (state-return grafts))))
 279
 280   (with-cache (cons (derivation-file-name drv) outputs)
 281     (match (non-self-references references drv outputs)
 282       (()                                         ;no dependencies
 283        (return grafts))
 284       (deps                                       ;one or more dependencies
 285        (mlet %state-monad ((grafts (mapm %state-monad dependency-grafts deps)))
 286          (let ((grafts (delete-duplicates (concatenate grafts) equal?)))
 287            (match (filter (lambda (graft)
 288                             (member (graft-origin-file-name graft) deps))
 289                           grafts)
 290              (()
 291               (return grafts))
 292              ((applicable ..1)
 293               ;; Use APPLICABLE, the subset of GRAFTS that is really
 294               ;; applicable to DRV, to avoid creating several identical
 295               ;; grafted variants of DRV.
 296               (let* ((new    (graft-derivation/shallow store drv applicable
 297                                                        #:outputs outputs
 298                                                        #:guile guile
 299                                                        #:system system))
 300                      (grafts (append (map (lambda (output)
 301                                             (graft
 302                                               (origin drv)
 303                                               (origin-output output)
 304                                               (replacement new)
 305                                               (replacement-output output)))
 306                                           outputs)
 307                                      grafts)))
 308                 (return grafts))))))))))
 309
 310 (define* (graft-derivation store drv grafts
 311                            #:key
 312                            (guile (%guile-for-build))
 313                            (outputs (derivation-output-names drv))
 314                            (system (%current-system)))
 315   "Apply GRAFTS to the OUTPUTS of DRV and all their dependencies, recursively.
 316 That is, if GRAFTS apply only indirectly to DRV, graft the dependencies of
 317 DRV, and graft DRV itself to refer to those grafted dependencies."
 318
 319   ;; First, pre-compute the dependency tree of the outputs of DRV.  Do this
 320   ;; upfront to have as much parallelism as possible when querying substitute
 321   ;; info or when building DRV.
 322   (define references
 323     (references-oracle store (derivation-input drv outputs)))
 324
 325   (match (run-with-state
 326              (cumulative-grafts store drv grafts references
 327                                 #:outputs outputs
 328                                 #:guile guile #:system system)
 329            vlist-null)                            ;the initial cache
 330     ((first . rest)
 331      ;; If FIRST is not a graft for DRV, it means that GRAFTS are not
 332      ;; applicable to DRV and nothing needs to be done.
 333      (if (equal? drv (graft-origin first))
 334          (graft-replacement first)
 335          drv))))
 336
 337 \f
 338 ;; The following might feel more at home in (guix packages) but since (guix
 339 ;; gexp), which is a lower level, needs them, we put them here.
 340
 341 (define %graft?
 342   ;; Whether to honor package grafts by default.
 343   (make-parameter #t))
 344
 345 (define (set-grafting enable?)
 346   "This monadic procedure enables grafting when ENABLE? is true, and disables
 347 it otherwise.  It returns the previous setting."
 348   (lambda (store)
 349     (values (%graft? enable?) store)))
 350
 351 (define (grafting?)
 352   "Return a Boolean indicating whether grafting is enabled."
 353   (lambda (store)
 354     (values (%graft?) store)))
 355
 356 ;; Local Variables:
 357 ;; eval: (put 'with-cache 'scheme-indent-function 1)
 358 ;; End:
 359
 360 ;;; grafts.scm ends here