build: Add julia-build-system.

* guix/build/julia-build-system.scm: New file.
* guix/build-system/julia.scm: New file.
* Makefile.am (MODULES): Add them.
* doc/guix.texi (Build Systems): Document julia-build-system.

Signed-off-by: Julien Lepiller <julien@lepiller.eu>

1 files changed, 135 insertions, 0 deletions

diff --git a/guix/build/julia-build-system.scm b/guix/build/julia-build-system.scm
new file mode 100644
index 0000000000..ff6fcf5fe3
--- /dev/null
+++ b/guix/build/julia-build-system.scm
@@ -0,0 +1,135 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2019 Nicolò Balzarotti <nicolo@nixo.xyz>
+;;;
+;;; 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 julia-build-system)
+  #:use-module ((guix build gnu-build-system) #:prefix gnu:)
+  #:use-module (guix build utils)
+  #:use-module (ice-9 match)
+  #:export (%standard-phases
+            julia-create-package-toml
+            julia-build))
+
+;; Commentary:
+;;
+;; Builder-side code of the standard build procedure for Julia packages.
+;;
+;; Code:
+
+(define (invoke-julia code)
+  (invoke "julia" "-e" code))
+
+;; subpath where we store the package content
+(define %package-path "/share/julia/packages/")
+
+(define (generate-load-path inputs outputs)
+  (string-append
+   (string-join (map (match-lambda
+                       ((_ . path)
+                        (string-append path %package-path)))
+                     ;; Restrict to inputs beginning with "julia-".
+                     (filter (match-lambda
+                               ((name . _)
+                                (string-prefix? "julia-" name)))
+                             inputs))
+                ":")
+   (string-append ":" (assoc-ref outputs "out") %package-path)
+   ;; stdlib is always required to find Julia's standard libraries.
+   ;; usually there are other two paths in this variable:
+   ;; "@" and "@v#.#"
+   ":@stdlib"))
+
+(define* (install #:key source inputs outputs #:allow-other-keys)
+  (let* ((out (assoc-ref outputs "out"))
+         (package-dir (string-append out %package-path
+                                     (string-append
+                                      (strip-store-file-name source)))))
+    (setenv "JULIA_LOAD_PATH" (generate-load-path inputs outputs))
+    (mkdir-p package-dir)
+    (copy-recursively source package-dir))
+  #t)
+
+;; TODO: Precompilation is working, but I don't know how to tell
+;; julia to use use it. If (on rantime) we set HOME to
+;; store path, julia tries to write files there (failing)
+(define* (precompile #:key source inputs outputs #:allow-other-keys)
+  (let* ((out (assoc-ref outputs "out"))
+         (builddir (string-append out "/share/julia/"))
+         (package (strip-store-file-name source)))
+    (mkdir-p builddir)
+    (setenv "JULIA_DEPOT_PATH" builddir)
+    (setenv "JULIA_LOAD_PATH" (generate-load-path inputs outputs))
+    ;; Actual precompilation
+    (invoke-julia (string-append "using " package)))
+  #t)
+
+(define* (check #:key source inputs outputs #:allow-other-keys)
+  (let* ((out (assoc-ref outputs "out"))
+         (package (strip-store-file-name source))
+         (builddir (string-append out "/share/julia/")))
+    (setenv "JULIA_DEPOT_PATH" builddir)
+    (setenv "JULIA_LOAD_PATH" (generate-load-path inputs outputs))
+    (invoke-julia (string-append "using Pkg;Pkg.test(\"" package "\")")))
+  #t)
+
+(define (julia-create-package-toml outputs source
+                                   name uuid version
+                                   deps)
+  "Some packages are not using the new Package.toml dependency specifications.
+Write this file manually, so that Julia can find its dependencies."
+  (let ((f (open-file
+            (string-append
+             (assoc-ref outputs "out")
+             %package-path
+             (string-append
+              name "/Project.toml"))
+            "w")))
+    (display (string-append
+              "
+name = \"" name "\"
+uuid = \"" uuid "\"
+version = \"" version "\"
+") f)
+    (when (not (null? deps))
+      (display "[deps]\n" f)
+      (for-each (lambda dep
+                  (display (string-append (car (car dep)) " = \"" (cdr (car dep)) "\"\n")
+                           f))
+                deps))
+    (close-port f))
+  #t)
+
+(define %standard-phases
+  (modify-phases gnu:%standard-phases
+    (delete 'check) ; tests must be run after installation
+    (replace 'install install)
+    (add-after 'install 'precompile precompile)
+    ;; (add-after 'install 'check check)
+    ;; TODO: In the future we could add a "system-image-generation" phase
+    ;; where we use PackageCompiler.jl to speed up package loading times
+    (delete 'configure)
+    (delete 'bootstrap)
+    (delete 'patch-usr-bin-file)
+    (delete 'build)))
+
+(define* (julia-build #:key inputs (phases %standard-phases)
+                      #:allow-other-keys #:rest args)
+  "Build the given Julia package, applying all of PHASES in order."
+  (apply gnu:gnu-build
+         #:inputs inputs #:phases phases
+         args))