[bug#64188] [PATCH 6/8] transformations: Allow tuning go packages.

[Efraim Flashner <efraim@flashner.co.il>]

* guix/transformations.scm (tuned-package)[build-system]: Don't replace
the build-system if inheriting from the go-build-system.
[arguments]: If using the go-build-system add a phase to set the
micro-architecture for Go.
---
 guix/transformations.scm | 35 ++++++++++++++++++++++++++++++++---
 1 file changed, 32 insertions(+), 3 deletions(-)

diff --git a/guix/transformations.scm b/guix/transformations.scm
index a289f81219..47eb4b0515 100644
--- a/guix/transformations.scm
+++ b/guix/transformations.scm
@@ -2,6 +2,7 @@
 ;;; Copyright © 2016-2023 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2021 Marius Bakke <marius@gnu.org>
 ;;; Copyright © 2023 Sarthak Shah <shahsarthakw@gmail.com>
+;;; Copyright © 2023 Efraim Flashner <efraim@flashner.co.il>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -570,14 +571,42 @@ (define (tuned-package p micro-architecture)
   (package
     (inherit p)
     (build-system
-      (build-system-with-tuning-compiler (package-build-system p)
-                                         micro-architecture))
+      ;; The go compiler doesn't need to be wrapped.
+      ;; XXX: This is where we check for supported micro-architectures.
+      (if (eq? (build-system-name (package-build-system p))
+               'go)
+        (package-build-system p)
+        (build-system-with-tuning-compiler (package-build-system p)
+                                           micro-architecture)))
     (arguments
      ;; The machine building this package may or may not be able to run code
      ;; for MICRO-ARCHITECTURE.  Because of that, skip tests; they are run for
      ;; the "baseline" variant anyway.
      (substitute-keyword-arguments (package-arguments p)
-       ((#:tests? _ #f) #f)))
+       ((#:tests? _ #f) #f)
+       ;; We add the tuning parameter after the default GO flags are set.
+       ((#:phases phases '%standard-phases)
+        (if (eq? (build-system-name (package-build-system p))
+                 'go)
+          #~(modify-phases #$phases
+              (add-after 'setup-go-environment 'set-microarchitecture
+                (lambda _
+                  (let ((microarch #$micro-architecture))
+                    (cond
+                      ((string-prefix? "arm" microarch)
+                       (setenv "GOARM" (string-take-right microarch 1))
+                       (format #t "Setting GOARM to ~s."
+                               (getenv "GOARM")))
+                      ((string-prefix? "powerpc" microarch)
+                       (setenv "GOPPC64" microarch)
+                       (format #t "Setting GOPPC64 to ~s."
+                               (getenv "GOPPC64")))
+                      ((string-prefix? "x86_64" microarch)
+                       (setenv "GOAMD" (string-take-right microarch 2))
+                       (format #t "Setting GOAMD to ~s.\n"
+                               (getenv "GOAMD")))
+                      (else #t))))))
+          phases))))
 
     (properties
      `((cpu-tuning . ,micro-architecture)
-- 
Efraim Flashner   <efraim@flashner.co.il>   רנשלפ םירפא
GPG key = A28B F40C 3E55 1372 662D  14F7 41AA E7DC CA3D 8351
Confidentiality cannot be guaranteed on emails sent or received unencrypted