bug#50299: [PATCH v3 09/27] gnu: swi-prolog: Set PROG_SWIPL when cross-compiling.

[Maxime Devos]

* gnu/packages/prolog.scm
  (swi-prolog)[arguments]<#:configure-flags>: Set PROG_SWIPL and
  SWIPL_NATIVE_FRIEND when cross-compiling.
  (swi-prolog)[native-inputs]: Add 'this-package' when cross-compiling.
---
 gnu/packages/prolog.scm | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/gnu/packages/prolog.scm b/gnu/packages/prolog.scm
index 3eaec533d7..7a5ac04a0c 100644
--- a/gnu/packages/prolog.scm
+++ b/gnu/packages/prolog.scm
@@ -27,6 +27,7 @@
   #:use-module (guix packages)
   #:use-module (guix build-system cmake)
   #:use-module (guix build-system gnu)
+  #:use-module (guix utils)
   #:use-module (gnu packages backup)
   #:use-module (gnu packages bash)
   #:use-module (gnu packages compression)
@@ -107,6 +108,12 @@ manner.  It also features an interactive interpreter.")
                    '("-DBSD_SIGNALS=1" "-DQSORT_R_GNU=1"
                      ;; If absent, the non-existent 'cc' is used.
                      "-DCMAKE_HOST_CC=gcc"
+                     ;; swi-prolog needs a native copy of itself for
+                     ;; cross-compilation.
+                     "-DSWIPL_NATIVE_FRIEND=/nowhere"
+                     (string-append "-DPROG_SWIPL="
+                                    (assoc-ref %build-host-inputs "swi-prolog")
+                                    "/bin/swipl"))
                    '())
              "-DINSTALL_DOCUMENTATION=ON"
              "-DSWIPL_INSTALL_IN_LIB=OFF") ; FIXME: Breaks RUNPATH validation.
@@ -125,7 +132,15 @@ manner.  It also features an interactive interpreter.")
                          '("save")))
              #t)))))
     (native-inputs
-     `(("texinfo" ,texinfo)
+     `(,@(if (%current-target-system)
+             (begin
+               (unless (equal? (target-64bit?)
+                               (target-64bit? (%current-system)))
+                 (error "swi-prolog requires --system and --target to have \
+the same word size"))
+               `(("swi-prolog" ,this-package)))
+             '())
+       ("texinfo" ,texinfo)
        ("perl" ,perl)
        ("pkg-config" ,pkg-config)))
     (inputs
-- 
2.33.0