[PATCH] Support cross compilation

[Christopher Baines]

With these changes, I was able to cross-compile guile-lib to the GNU
Hurd, and use part of the library at least.

* configure.ac: Set GUILE_TARGET when cross compiling.
* am/guile.mk: Pass GUILE_TARGET to guild compile.
---
 am/guile.mk  | 2 +-
 configure.ac | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/am/guile.mk b/am/guile.mk
index 3adfc4f..f08e58d 100644
--- a/am/guile.mk
+++ b/am/guile.mk
@@ -47,4 +47,4 @@ GUILE_WARNINGS = -Wunbound-variable -Warity-mismatch -Wformat
 SUFFIXES = .scm .go
 .scm.go:
        $(AM_V_GEN)$(top_builddir)/pre-inst-env \
-       guild compile $(GUILE_WARNINGS) -o "$@" "$<"
+       guild compile $(GUILE_TARGET) $(GUILE_WARNINGS) -o "$@" "$<"
diff --git a/configure.ac b/configure.ac
index 07be121..0aa812f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -67,6 +67,10 @@ GUILE_GLOBAL_SITE_DIR
 GUILE_SITE_CCACHE_DIR
 GUILE_FLAGS
 
+if test \"$cross_compiling\" != no; then
+   GUILE_TARGET=\"--target=$host_alias\"
+   AC_SUBST([GUILE_TARGET])
+fi
 
 AC_ARG_WITH(
   [guile-site],
-- 
2.30.0