01/44: gnu: autoconf: Support cross-build.

[guix-commits]

janneke pushed a commit to branch wip-hurd-vm
in repository guix.

commit d192d886eb0f76222f6bf7a04744dcff3bc48731
Author: Jan (janneke) Nieuwenhuizen <address@hidden>
AuthorDate: Sat Apr 18 19:49:54 2020 +0200

    gnu: autoconf: Support cross-build.
    
    Autoconf cannot be cross-built properly: it lacks the concept of
    <tool>-for-build.  It runs the host `autom4te' (a perl script) during build.
    
    * gnu/packages/autotools.scm (autoconf)[inputs]: When cross-building, add 
perl
    and m4.
    [native-inputs]: when cross-building, use -for-build names.
    [arguments]: When cross-building, add `patch-non-shebang-references' phase 
to
    substitute m4 and perl.
---
 gnu/packages/autotools.scm | 28 +++++++++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/gnu/packages/autotools.scm b/gnu/packages/autotools.scm
index 99ca527..fa3ced1 100644
--- a/gnu/packages/autotools.scm
+++ b/gnu/packages/autotools.scm
@@ -55,12 +55,38 @@
        (base32
         "113nlmidxy9kjr45kg9x3ngar4951mvag1js2a3j8nxcz34wxsv4"))))
     (build-system gnu-build-system)
+    (inputs
+     ;; TODO: remove `if' in the next rebuild cycle.
+     (if (%current-target-system)
+         `(("perl" ,perl)
+           ("m4" ,m4))
+         '()))
     (native-inputs
      `(("perl" ,perl)
        ("m4" ,m4)))
     ;; XXX: testsuite: 209 and 279 failed. The latter is an impurity. It
     ;; should use our own "cpp" instead of "/lib/cpp".
-    (arguments `(#:tests? #f))
+    (arguments
+     `(#:tests? #f
+       ,@(if (%current-target-system)
+             `(#:phases
+               (modify-phases %standard-phases
+                 ;; `patch-shebangs' patches shebangs only, and the Perl
+                 ;; scripts use a re-exec feature that references the build
+                 ;; hosts' perl.  Also, M4 store references hide in the
+                 ;; scripts.
+                 (add-after 'install 'patch-non-shebang-references
+                   (lambda* (#:key build inputs outputs #:allow-other-keys)
+                     (let ((m4 (assoc-ref inputs "m4"))
+                           (perl (assoc-ref inputs "perl"))
+                           (out  (assoc-ref outputs "out"))
+                           (store-directory (%store-directory)))
+                      (substitute* (find-files (string-append out "/bin"))
+                        (((string-append store-directory "/[^/]*-m4-[^/]*")) 
m4)
+                        (((string-append store-directory "/[^/]*-perl-[^/]*"))
+                         perl))
+                      #t)))))
+             '())))
     (home-page "https://www.gnu.org/software/autoconf/";)
     (synopsis "Create source code configuration scripts")
     (description