build-system: Add zig-build-system.

* guix/build-system/zig.scm: New file.
* guix/build/zig-build-system.scm: New file.
* Makefile.am: Add them.
* doc/guix.texi: Document it.
* etc/snippets/yas/scheme-mode/guix-package (build-system): Add
  zig-build-system.

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

1 files changed, 100 insertions, 0 deletions

diff --git a/guix/build/zig-build-system.scm b/guix/build/zig-build-system.scm
new file mode 100644
index 0000000000..d414ebfb17
--- /dev/null
+++ b/guix/build/zig-build-system.scm
@@ -0,0 +1,100 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2023 Ekaitz Zarraga <ekaitz@elenq.tech>
+;;;
+;;; 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 zig-build-system)
+  #:use-module ((guix build gnu-build-system) #:prefix gnu:)
+  #:use-module (guix build utils)
+  #:use-module (ice-9 popen)
+  #:use-module (ice-9 rdelim)
+  #:use-module (ice-9 ftw)
+  #:use-module (ice-9 format)
+  #:use-module (ice-9 match)
+  #:use-module (rnrs io ports)
+  #:use-module (srfi srfi-1)
+  #:use-module (srfi srfi-26)
+  #:export (%standard-phases
+            zig-build))
+
+;; Interesting guide here:
+;; https://github.com/riverwm/river/blob/master/PACKAGING.md
+(define global-cache-dir "zig-cache")
+
+(define* (set-cc #:rest args)
+  ;; TODO: Zig needs the gcc-toolchain in order to find the libc.
+  ;;       we need to think about how to solve this in the build system
+  ;;       directly: --libc
+  (setenv "CC" "gcc"))
+
+(define* (set-zig-global-cache-dir #:rest args)
+  (setenv "ZIG_GLOBAL_CACHE_DIR" global-cache-dir))
+
+(define* (build #:key
+                zig-build-flags
+                zig-release-type       ;; "safe", "fast" or "small" empty for a
+                                       ;; debug build"
+                #:allow-other-keys)
+  "Build a given Zig package."
+
+  (setenv "DESTDIR" "out")
+  (let ((call `("zig" "build"
+                     "--prefix"             ""            ;; Don't add /usr
+                     "--prefix-lib-dir"     "lib"
+                     "--prefix-exe-dir"     "bin"
+                     "--prefix-include-dir" "include"
+                     ,@(if zig-release-type
+                         (list (string-append "-Drelease-" zig-release-type))
+                         '())
+                     ,@zig-build-flags)))
+  (format #t "running: ~s~%" call)
+  (apply invoke call)))
+
+(define* (check #:key tests?
+                zig-test-flags
+                #:allow-other-keys)
+  "Run all the tests"
+  (when tests?
+    (let ((old-destdir (getenv "DESTDIR")))
+      (setenv "DESTDIR" "test-out") ;; Avoid colisions with the build output
+      (let ((call `("zig" "build" "test"
+                    ,@zig-test-flags)))
+        (format #t "running: ~s~%" call)
+        (apply invoke call))
+      (if old-destdir
+        (setenv "DESTDIR" old-destdir)
+        (unsetenv "DESTDIR")))))
+
+(define* (install #:key inputs outputs #:allow-other-keys)
+  "Install a given Zig package."
+  (let ((out (assoc-ref outputs "out")))
+    (copy-recursively "out" out)))
+
+(define %standard-phases
+  (modify-phases gnu:%standard-phases
+    (delete 'bootstrap)
+    (delete 'configure)
+    (add-before 'build 'set-zig-global-cache-dir set-zig-global-cache-dir)
+    (add-before 'build 'set-cc set-cc)
+    (replace 'build build)
+    (replace 'check check)
+    (replace 'install install)))
+
+
+(define* (zig-build #:key inputs (phases %standard-phases)
+                      #:allow-other-keys #:rest args)
+  "Build the given Zig package, applying all of PHASES in order."
+  (apply gnu:gnu-build #:inputs inputs #:phases phases args))