grafts: Allow file-like objects in the ‘replacement’ field of <graft>.

This is a followup to and simplification of
3331d675fbf5287e8cbe12af48fb2de14f1ad8bc.

* guix/grafts.scm (graft-derivation/shallow)[mapping]: Wrap origin and
replacement in ‘with-parameters’.
(cumulative-grafts)[finalize-graft]: Remove, and remove its sole user.
* guix/packages.scm (input-graft, input-cross-graft): Add ‘replacement’
straight into the ‘replacement’ field of <graft>.
* tests/packages.scm ("package-grafts, indirect grafts")
("package-grafts, indirect grafts, propagated inputs")
("package-grafts, same replacement twice")
("package-grafts, dependency on several outputs")
("replacement also grafted"): Adjust accordingly.

Suggested-by: David Elsing <[email protected]>
Change-Id: I286fceae53df9d3051137bbca5f944d51d0c92f3

3 files changed, 21 insertions, 49 deletions

diff --git a/guix/grafts.scm b/guix/grafts.scm
index 7636df9267..98ef1e4058 100644
--- a/guix/grafts.scm
+++ b/guix/grafts.scm
@@ -101,9 +101,11 @@ are not recursively applied to dependencies of DRV."
     ;; List of store item pairs.
     (map (lambda (graft)
            (gexp
-            ((ungexp (graft-origin graft)
+            ((ungexp (with-parameters ((%graft? #f))
+                       (graft-origin graft))
                      (graft-origin-output graft))
-             . (ungexp (graft-replacement graft)
+             . (ungexp (with-parameters ((%graft? #t))
+                         (graft-replacement graft))
                        (graft-replacement-output graft)))))
          grafts))
 
@@ -275,20 +277,6 @@ derivations to the corresponding set of grafts."
                                       #:system system)))))
           (reference-origins drv items)))
 
-  ;; If the 'replacement' field of the <graft> record is a procedure,
-  ;; this means that it is a value in the store monad and the actual
-  ;; derivation needs to be computed here.
-  (define (finalize-graft item)
-    (let ((replacement (graft-replacement item)))
-      (if (procedure? replacement)
-          (graft
-            (inherit item)
-            (replacement
-             (run-with-store store replacement
-                             #:guile-for-build guile
-                             #:system system)))
-          item)))
-
   (with-cache (list (derivation-file-name drv) outputs grafts)
     (match (non-self-references store drv outputs)
       (()                                         ;no dependencies
@@ -305,8 +293,7 @@ derivations to the corresponding set of grafts."
               ;; Use APPLICABLE, the subset of GRAFTS that is really
               ;; applicable to DRV, to avoid creating several identical
               ;; grafted variants of DRV.
-              (let* ((new    (graft-derivation/shallow* store drv
-                                                        (map finalize-graft applicable)
+              (let* ((new    (graft-derivation/shallow* store drv applicable
                                                         #:outputs outputs
                                                         #:guile guile
                                                         #:system system))
diff --git a/guix/packages.scm b/guix/packages.scm
index d266805ba8..78726b089a 100644
--- a/guix/packages.scm
+++ b/guix/packages.scm
@@ -1818,15 +1818,13 @@ graft, and #f otherwise."
          (if replacement
              (mcached eq? (=> %package-graft-cache)
                       (mlet %store-monad ((orig (package->derivation package system
-                                                                     #:graft? #f))
-                                          (new -> (package->derivation replacement system
-                                                                       #:graft? #t)))
-                        ;; Keep NEW as a monadic value so that its computation
-                        ;; is delayed until necessary.
+                                                                     #:graft? #f)))
+                        ;; Keep REPLACEMENT as a package so that its
+                        ;; derivation is computed only when necessary.
                         (return (graft
                                   (origin orig)
                                   (origin-output output)
-                                  (replacement new)
+                                  (replacement replacement)
                                   (replacement-output output))))
                       package output system)
              (return #f))))
@@ -1842,16 +1840,13 @@ graft, and #f otherwise."
          (if replacement
              (mlet %store-monad ((orig (package->cross-derivation package
                                                                   target system
-                                                                  #:graft? #f))
-                                 (new -> (package->cross-derivation replacement
-                                                                    target system
-                                                                    #:graft? #t)))
-               ;; Keep NEW as a monadic value so that its computation
-               ;; is delayed until necessary.
+                                                                  #:graft? #f)))
+               ;; Keep REPLACEMENT as a package so that its derivation is
+               ;; computed only when necessary.
                (return (graft
                          (origin orig)
                          (origin-output output)
-                         (replacement new)
+                         (replacement replacement)
                          (replacement-output output))))
              (return #f))))
       (_
diff --git a/tests/packages.scm b/tests/packages.scm
index a4a0e2c3e8..2863fb5991 100644
--- a/tests/packages.scm
+++ b/tests/packages.scm
@@ -1095,9 +1095,7 @@
       ((graft)
        (and (eq? (graft-origin graft)
                  (package-derivation %store dep))
-            (eq? (run-with-store %store
-                   (graft-replacement graft))
-                 (package-derivation %store new)))))))
+            (eq? (graft-replacement graft) new))))))
 
 ;; XXX: This test would require building the cross toolchain just to see if it
 ;; needs grafting, which is obviously too expensive, and thus disabled.
@@ -1134,9 +1132,7 @@
       ((graft)
        (and (eq? (graft-origin graft)
                  (package-derivation %store dep))
-            (eq? (run-with-store %store
-                   (graft-replacement graft))
-                 (package-derivation %store new)))))))
+            (eq? (graft-replacement graft) new))))))
 
 (test-assert "package-grafts, same replacement twice"
   (let* ((new  (dummy-package "dep"
@@ -1161,9 +1157,7 @@
                  (package-derivation %store
                                      (package (inherit dep)
                                               (replacement #f))))
-            (eq? (run-with-store %store
-                   (graft-replacement graft))
-                 (package-derivation %store new)))))))
+            (eq? (graft-replacement graft) new))))))
 
 (test-assert "package-grafts, dependency on several outputs"
   ;; Make sure we get one graft per output; see <https://bugs.gnu.org/41796>.
@@ -1183,9 +1177,9 @@
       ((graft1 graft2)
        (and (eq? (graft-origin graft1) (graft-origin graft2)
                  (package-derivation %store p0))
-            (eq? (run-with-store %store (graft-replacement graft1))
-                 (run-with-store %store (graft-replacement graft2))
-                 (package-derivation %store p0*))
+            (eq? (graft-replacement graft1)
+                 (graft-replacement graft2)
+                 p0*)
             (string=? "lib"
                       (graft-origin-output graft1)
                       (graft-replacement-output graft1))
@@ -1262,14 +1256,10 @@
       ((graft1 graft2)
        (and (eq? (graft-origin graft1)
                  (package-derivation %store p1 #:graft? #f))
-            (eq? (run-with-store %store
-                   (graft-replacement graft1))
-                 (package-derivation %store p1r))
+            (eq? (graft-replacement graft1) p1r)
             (eq? (graft-origin graft2)
                  (package-derivation %store p2 #:graft? #f))
-            (eq? (run-with-store %store
-                   (graft-replacement graft2))
-                 (package-derivation %store p2r #:graft? #t)))))))
+            (eq? (graft-replacement graft2) p2r))))))
 
 ;;; XXX: Nowadays 'graft-derivation' needs to build derivations beforehand to
 ;;; find out about their run-time dependencies, so this test is no longer