Re: x-to-1

[Bruno Haible]

Reuben Thomas wrote:
> It would be good to document that x-to-1 needs CROSS_COMPILING and PERL set
> up by configure.ac. Or perhaps it's worth a gnulib module?

Good point. I think putting these tests into a Gnulib module 'x-to-1' would
not be the right approach, because
  - there are several ways to test for 'perl': with a minimum version and
    without,
  - there are several ways to test for cross-compilation: Some programs use
    AC_PROG_CC, some use AC_PROG_CXX instead.


2023-02-08  Bruno Haible  <bruno@clisp.org>

        x-to-1: Document the configure-time prerequisites.
        Suggested by Reuben Thomas <rrt@sc3d.org> in
        <https://lists.gnu.org/archive/html/bug-gnulib/2023-02/msg00078.html>.
        * build-aux/x-to-1.in: Add more comments.

diff --git a/build-aux/x-to-1.in b/build-aux/x-to-1.in
index 50fb5bb2c7..6dc01157f5 100644
--- a/build-aux/x-to-1.in
+++ b/build-aux/x-to-1.in
@@ -35,7 +35,18 @@
 #
 # Options:
 #   --update    Don't overwrite the output if nothing would change.
-
+#
+# Configure-time prerequisites:
+#
+#   PERL        Can be set through
+#                 ac_aux_dir_abs=`cd $ac_aux_dir && pwd`
+#                 AC_PATH_PROG([PERL], [perl], [$ac_aux_dir_abs/missing perl])
+#               or, alternatively, by the Gnulib 'perl' module.
+#
+#   CROSS_COMPILING  Can be set through
+#                      CROSS_COMPILING=$cross_compiling
+#                      AC_SUBST([CROSS_COMPILING])
+#                    The variable 'cross_compiling' is set by AC_PROG_CC.
 
 update=
 while true; do