import: opam: Factor out source import.

This also ensures a package can be imported even when it does not
specify a URL.

* guix/import/opam.scm (opam->guix-source): New procedure.
(opam->guix-package): Use it.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

1 files changed, 43 insertions, 38 deletions

diff --git a/guix/import/opam.scm b/guix/import/opam.scm
index f51d17dea4..b4b5a6eaad 100644
--- a/guix/import/opam.scm
+++ b/guix/import/opam.scm
@@ -324,6 +324,20 @@ path to the repository."
             (filter-map get-opam-repository repositories-specs))
       (warning (G_ "opam: package '~a' not found~%") name)))
 
+(define (opam->guix-source url-dict)
+  (let ((source-url (and url-dict
+                         (or (metadata-ref url-dict "src")
+                             (metadata-ref url-dict "archive")))))
+    (if source-url
+        (call-with-temporary-output-file
+          (lambda (temp port)
+            (and (url-fetch source-url temp)
+                 `(origin
+                    (method url-fetch)
+                    (uri ,source-url)
+                    (sha256 (base32 ,(guix-hash-url temp)))))))
+        'no-source-information)))
+
 (define* (opam->guix-package name #:key (repo 'opam) version)
   "Import OPAM package NAME from REPOSITORY (a directory name) or, if
 REPOSITORY is #f, from the official OPAM repository.  Return a 'package' sexp
@@ -332,9 +346,7 @@ or #f on failure."
              (opam-file (opam-fetch name with-opam))
              (version (assoc-ref opam-file "version"))
              (opam-content (assoc-ref opam-file "metadata"))
-             (url-dict (metadata-ref opam-content "url"))
-             (source-url (or (metadata-ref url-dict "src")
-                             (metadata-ref url-dict "archive")))
+             (source (opam->guix-source (metadata-ref opam-content "url")))
              (requirements (metadata-ref opam-content "depends"))
              (names (dependency-list->names requirements))
              (dependencies (filter-dependencies names))
@@ -348,41 +360,34 @@ or #f on failure."
                                   (not (member name '("dune" "jbuilder"))))
                                 native-dependencies))))
         (let ((use-dune? (member "dune" names)))
-          (call-with-temporary-output-file
-            (lambda (temp port)
-              (and (url-fetch source-url temp)
-                   (values
-                    `(package
-                       (name ,(ocaml-name->guix-name name))
-                       (version ,version)
-                       (source
-                         (origin
-                           (method url-fetch)
-                           (uri ,source-url)
-                           (sha256 (base32 ,(guix-hash-url temp)))))
-                       (build-system ,(if use-dune?
-                                          'dune-build-system
-                                          'ocaml-build-system))
-                       ,@(if (null? inputs)
-                           '()
-                           `((propagated-inputs (list ,@inputs))))
-                       ,@(if (null? native-inputs)
-                           '()
-                           `((native-inputs (list ,@native-inputs))))
-                       ,@(if (equal? name (guix-name->opam-name (ocaml-name->guix-name name)))
-                           '()
-                           `((properties
-                               ,(list 'quasiquote `((upstream-name . ,name))))))
-                       (home-page ,(metadata-ref opam-content "homepage"))
-                       (synopsis ,(metadata-ref opam-content "synopsis"))
-                       (description ,(beautify-description
-                                      (metadata-ref opam-content "description")))
-                       (license ,(spdx-string->license
-                                  (metadata-ref opam-content "license"))))
-                    (filter
-                      (lambda (name)
-                        (not (member name '("dune" "jbuilder"))))
-                      dependencies))))))))
+          (values
+           `(package
+              (name ,(ocaml-name->guix-name name))
+              (version ,version)
+              (source ,source)
+              (build-system ,(if use-dune?
+                                 'dune-build-system
+                                 'ocaml-build-system))
+              ,@(if (null? inputs)
+                  '()
+                  `((propagated-inputs (list ,@inputs))))
+              ,@(if (null? native-inputs)
+                  '()
+                  `((native-inputs (list ,@native-inputs))))
+              ,@(if (equal? name (guix-name->opam-name (ocaml-name->guix-name name)))
+                  '()
+                  `((properties
+                      ,(list 'quasiquote `((upstream-name . ,name))))))
+              (home-page ,(metadata-ref opam-content "homepage"))
+              (synopsis ,(metadata-ref opam-content "synopsis"))
+              (description ,(beautify-description
+                             (metadata-ref opam-content "description")))
+              (license ,(spdx-string->license
+                         (metadata-ref opam-content "license"))))
+           (filter
+             (lambda (name)
+               (not (member name '("dune" "jbuilder"))))
+             dependencies)))))
 
 (define* (opam-recursive-import package-name #:key repo)
   (recursive-import package-name