guix package: Allow removal of a specific package output.

Fixes <http://bugs.gnu.org/15756>.

* guix/profiles.scm (<manifest-pattern>): New record type.
  (remove-manifest-entry): Remove.
  (entry-predicate, manifest-matching-entries): New procedures.
  (manifest-remove): Accept a list of <manifest-pattern>.
  (manifest-installed?): Replace 'name' parameter by 'pattern', a
  <manifest-pattern>.
* guix/scripts/package.scm (options->removable): Return a list of
  <manifest-pattern>.
  (guix-package)[process-action]: Use 'manifest-matching-entries' to
  compute the list of packages to remove.
* tests/profiles.scm: New file.
* Makefile.am (SCM_TESTS): Add it.

2 files changed, 67 insertions, 29 deletions

diff --git a/guix/profiles.scm b/guix/profiles.scm
index 528f3c574b..1f62099e45 100644
--- a/guix/profiles.scm
+++ b/guix/profiles.scm
@@ -42,11 +42,15 @@
             manifest-entry-path
             manifest-entry-dependencies
 
+            manifest-pattern
+            manifest-pattern?
+
             read-manifest
             write-manifest
 
             manifest-remove
             manifest-installed?
+            manifest-matching-entries
             manifest=?
 
             profile-manifest
@@ -90,6 +94,15 @@
   (inputs       manifest-entry-inputs             ; list of inputs to build
                 (default '())))                   ; this entry
 
+(define-record-type* <manifest-pattern> manifest-pattern
+  make-manifest-pattern
+  manifest-pattern?
+  (name         manifest-pattern-name)            ; string
+  (version      manifest-pattern-version          ; string | #f
+                (default #f))
+  (output       manifest-pattern-output           ; string | #f
+                (default "out")))
+
 (define (profile-manifest profile)
   "Return the PROFILE's manifest."
   (let ((file (string-append profile "/manifest")))
@@ -148,29 +161,48 @@
   "Write MANIFEST to PORT."
   (write (manifest->sexp manifest) port))
 
-(define (remove-manifest-entry name lst)
-  "Remove the manifest entry named NAME from LST."
-  (remove (match-lambda
-           (($ <manifest-entry> entry-name)
-            (string=? name entry-name)))
-          lst))
-
-(define (manifest-remove manifest names)
-  "Remove entries for each of NAMES from MANIFEST."
-  (make-manifest (fold remove-manifest-entry
+(define (entry-predicate pattern)
+  "Return a procedure that returns #t when passed a manifest entry that
+matches NAME/OUTPUT/VERSION.  OUTPUT and VERSION may be #f, in which case they
+are ignored."
+  (match pattern
+    (($ <manifest-pattern> name version output)
+     (match-lambda
+      (($ <manifest-entry> entry-name entry-version entry-output)
+       (and (string=? entry-name name)
+            (or (not entry-output) (not output)
+                (string=? entry-output output))
+            (or (not version)
+                (string=? entry-version version))))))))
+
+(define (manifest-remove manifest patterns)
+  "Remove entries for each of PATTERNS from MANIFEST.  Each item in PATTERNS
+must be a manifest-pattern."
+  (define (remove-entry pattern lst)
+    (remove (entry-predicate pattern) lst))
+
+  (make-manifest (fold remove-entry
                        (manifest-entries manifest)
-                       names)))
-
-(define (manifest-installed? manifest name)
-  "Return #t if MANIFEST has an entry for NAME, #f otherwise."
-  (define (->bool x)
-    (not (not x)))
+                       patterns)))
 
-  (->bool (find (match-lambda
-                 (($ <manifest-entry> entry-name)
-                  (string=? entry-name name)))
+(define (manifest-installed? manifest pattern)
+  "Return #t if MANIFEST has an entry matching PATTERN (a manifest-pattern),
+#f otherwise."
+  (->bool (find (entry-predicate pattern)
                 (manifest-entries manifest))))
 
+(define (manifest-matching-entries manifest patterns)
+  "Return all the entries of MANIFEST that match one of the PATTERNS."
+  (define predicates
+    (map entry-predicate patterns))
+
+  (define (matches? entry)
+    (any (lambda (pred)
+           (pred entry))
+         predicates))
+
+  (filter matches? (manifest-entries manifest)))
+
 (define (manifest=? m1 m2)
   "Return #t if manifests M1 and M2 are equal.  This differs from 'equal?' in
 that the 'inputs' field is ignored for the comparison, since it is know to
diff --git a/guix/scripts/package.scm b/guix/scripts/package.scm
index e0c7b6ed15..77406c7f39 100644
--- a/guix/scripts/package.scm
+++ b/guix/scripts/package.scm
@@ -693,15 +693,20 @@ return the new list of manifest entries."
   (append to-upgrade to-install))
 
 (define (options->removable options manifest)
-  "Given options, return the list of manifest entries to be removed from
-MANIFEST."
-  (let ((remove (filter-map (match-lambda
-                             (('remove . package)
-                              package)
-                             (_ #f))
-                            options)))
-    (filter (cut manifest-installed? manifest <>)
-            remove)))
+  "Given options, return the list of manifest patterns of packages to be
+removed from MANIFEST."
+  (filter-map (match-lambda
+               (('remove . spec)
+                (call-with-values
+                    (lambda ()
+                      (package-specification->name+version+output spec))
+                  (lambda (name version output)
+                    (manifest-pattern
+                      (name name)
+                      (version version)
+                      (output output)))))
+               (_ #f))
+              options))
 
 
 ;;;
@@ -871,7 +876,8 @@ more information.~%"))
 
              (if (manifest=? new manifest)
                  (format (current-error-port) (_ "nothing to be done~%"))
-                 (let ((prof-drv (profile-derivation (%store) new)))
+                 (let ((prof-drv (profile-derivation (%store) new))
+                       (remove   (manifest-matching-entries manifest remove)))
                    (show-what-to-remove/install remove install dry-run?)
                    (show-what-to-build (%store) (list prof-drv)
                                        #:use-substitutes?