Add (guix svn-download).

* guix/svn-download.scm, guix/build/svn.scm: New files.
* Makefile.am (MODULES): Add them.

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

Makefile.am

@@ -52,6 +52,7 @@ MODULES =					\
   guix/http-client.scm				\
   guix/gnupg.scm				\
   guix/store.scm				\
+  guix/svn-download.scm				\
   guix/ui.scm					\
   guix/build/download.scm			\
   guix/build/cmake-build-system.scm		\
@@ -66,6 +67,7 @@ MODULES =					\
   guix/build/union.scm				\
   guix/build/pull.scm				\
   guix/build/rpath.scm				\
+  guix/build/svn.scm				\
   guix/packages.scm				\
   guix/snix.scm					\
   guix/scripts/download.scm			\

guix/build/svn.scm

@@ -0,0 +1,49 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2014 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2014 Sree Harsha Totakura <sreeharsha@totakura.in>
+;;;
+;;; 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 build svn)
+  #:use-module (guix build utils)
+  #:export (svn-fetch))
+
+;;; Commentary:
+;;;
+;;; This is the build-side support code of (guix svn-download).  It allows a
+;;; Subversion repository to be cloned and checked out at a specific revision.
+;;;
+;;; Code:
+
+(define* (svn-fetch url revision directory
+                    #:key (svn-command "svn"))
+  "Fetch REVISION from URL into DIRECTORY.  REVISION must be an integer, and a
+valid Subversion revision.  Return #t on success, #f otherwise."
+  (and (zero? (system* svn-command "checkout" "--non-interactive"
+                       ;; Trust the server certificate.  This is OK as we
+                       ;; verify the checksum later.  This can be removed when
+                       ;; ca-certificates package is added.
+                       "--trust-server-cert" "-r" (number->string revision)
+                       url directory))
+       (with-directory-excursion directory
+         (begin
+           ;; The contents of '.svn' vary as a function of the current status
+           ;; of the repo.  Since we want a fixed output, this directory needs
+           ;; to be taken out.
+           (delete-file-recursively ".svn")
+           #t))))
+
+;;; svn.scm ends here

guix/svn-download.scm

@@ -0,0 +1,90 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2014 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2014 Sree Harsha Totakura <sreeharsha@totakura.in>
+;;;
+;;; 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 svn-download)
+  #:use-module (guix records)
+  #:use-module (guix derivations)
+  #:use-module (guix packages)
+  #:use-module (ice-9 match)
+  #:export (svn-reference
+            svn-reference?
+            svn-reference-url
+            svn-reference-revision
+            svn-fetch))
+
+;;; Commentary:
+;;;
+;;; An <origin> method that fetches a specific revision from a Subversion
+;;; repository.  The repository URL and REVISION are specified with a
+;;; <svn-reference> object.  REVISION should be specified as a number.
+;;;
+;;; Code:
+
+(define-record-type* <svn-reference>
+  svn-reference make-svn-reference
+  svn-reference?
+  (url      svn-reference-url)                    ; string
+  (revision svn-reference-revision))              ; number
+
+(define* (svn-fetch store ref hash-algo hash
+                    #:optional name
+                    #:key (system (%current-system)) guile svn)
+  "Return a fixed-output derivation in STORE that fetches REF, a
+<svn-reference> object.  The output is expected to have recursive hash HASH of
+type HASH-ALGO (a symbol).  Use NAME as the file name, or a generic name if
+#f."
+  (define guile-for-build
+    (match guile
+      ((? package?)
+       (package-derivation store guile system))
+      (#f                                         ; the default
+       (let* ((distro (resolve-interface '(gnu packages base)))
+              (guile  (module-ref distro 'guile-final)))
+         (package-derivation store guile system)))))
+
+  (define svn-for-build
+    (match svn
+      ((? package?)
+       (package-derivation store svn system))
+      (#f                                         ; the default
+       (let* ((distro (resolve-interface '(gnu packages version-control)))
+              (svn    (module-ref distro 'subversion)))
+         (package-derivation store svn system)))))
+
+  (let* ((command (string-append (derivation->output-path svn-for-build)
+                                 "/bin/svn"))
+         (builder `(begin
+                     (use-modules (guix build svn))
+                     (svn-fetch ',(svn-reference-url ref)
+                                ',(svn-reference-revision ref)
+                                %output
+                                #:svn-command ',command))))
+    (build-expression->derivation store (or name "svn-checkout") builder
+                                  #:system system
+                                  #:local-build? #t
+                                  #:inputs `(("svn" ,svn-for-build))
+                                  #:hash-algo hash-algo
+                                  #:hash hash
+                                  #:recursive? #t
+                                  #:modules '((guix build svn)
+                                              (guix build utils))
+                                  #:guile-for-build guile-for-build
+                                  #:local-build? #t)))
+
+;;; svn-download.scm ends here