Merge branch '1978-cross-compilation-doesn-t-work-in-9-17' into 'main'

Resolve "Cross-compilation doesn’t work in 9.17"

Closes #1978

See merge request isc-projects/bind9!4505

configure.ac

@@ -65,8 +65,11 @@ AC_CONFIG_MACRO_DIR([m4])
 
 #
 # Enable maintainer mode by default only when building from git repository
+# and not cross compling
 #
-AM_MAINTAINER_MODE([m4_ifset([bind_SRCID],[enable],[disable])])
+AS_IF([test "$cross_compiling" = no],
+      [AM_MAINTAINER_MODE(m4_ifset([bind_SRCID],[enable],[disable]))],
+      [AM_MAINTAINER_MODE([disable])])
 
 # Set the library versions
 # https://www.gnu.org/software/libtool/manual/html_node/Updating-version-info.html
@@ -91,6 +94,11 @@ AC_CANONICAL_HOST
 AC_PROG_CC_C99
 AC_PROG_CPP_WERROR
 
+#
+# Find build compiler when cross compiling
+#
+AX_CC_FOR_BUILD
+
 #
 # Find the machine's endian flavor.
 #

lib/dns/Makefile.am

@@ -18,12 +18,8 @@ BUILT_SOURCES =				\
 CLEANFILES =				\
 	$(nodist_libdns_la_SOURCES)
 
-noinst_PROGRAMS = gen
-
-gen_SOURCES = gen.c gen-unix.h
-
-gen_CPPFLAGS =			\
-	$(AM_CPPFLAGS)
+gen$(BUILD_EXEEXT): gen.c gen-unix.h
+	$(CC_FOR_BUILD) -g -I. $(GEN_NEED_OPTARG) $(srcdir)/gen.c -o $@
 
 EXTRA_DIST =		\
 	api		\

m4/ax_cc_for_build.m4

@@ -0,0 +1,77 @@
+# ===========================================================================
+#     https://www.gnu.org/software/autoconf-archive/ax_cc_for_build.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_CC_FOR_BUILD
+#
+# DESCRIPTION
+#
+#   Find a build-time compiler. Sets CC_FOR_BUILD and EXEEXT_FOR_BUILD.
+#
+# LICENSE
+#
+#   Copyright (c) 2010 Reuben Thomas <rrt@sc3d.org>
+#   Copyright (c) 1999 Richard Henderson <rth@redhat.com>
+#
+#   This program is free software: you can redistribute it and/or modify it
+#   under the terms of the GNU General Public License as published by the
+#   Free Software Foundation, either version 3 of the License, or (at your
+#   option) any later version.
+#
+#   This program is distributed in the hope that it will be useful, but
+#   WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+#   Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License along
+#   with this program. If not, see <https://www.gnu.org/licenses/>.
+#
+#   As a special exception, the respective Autoconf Macro's copyright owner
+#   gives unlimited permission to copy, distribute and modify the configure
+#   scripts that are the output of Autoconf when processing the Macro. You
+#   need not follow the terms of the GNU General Public License when using
+#   or distributing such scripts, even though portions of the text of the
+#   Macro appear in them. The GNU General Public License (GPL) does govern
+#   all other use of the material that constitutes the Autoconf Macro.
+#
+#   This special exception to the GPL applies to versions of the Autoconf
+#   Macro released by the Autoconf Archive. When you make and distribute a
+#   modified version of the Autoconf Macro, you may extend this special
+#   exception to the GPL to apply to your modified version as well.
+
+#serial 3
+
+dnl Get a default for CC_FOR_BUILD to put into Makefile.
+AC_DEFUN([AX_CC_FOR_BUILD],
+[# Put a plausible default for CC_FOR_BUILD in Makefile.
+if test -z "$CC_FOR_BUILD"; then
+  if test "x$cross_compiling" = "xno"; then
+    CC_FOR_BUILD='$(CC)'
+  else
+    CC_FOR_BUILD=gcc
+  fi
+fi
+AC_SUBST(CC_FOR_BUILD)
+# Also set EXEEXT_FOR_BUILD.
+if test "x$cross_compiling" = "xno"; then
+  EXEEXT_FOR_BUILD='$(EXEEXT)'
+else
+  AC_CACHE_CHECK([for build system executable suffix], bfd_cv_build_exeext,
+    [rm -f conftest*
+     echo 'int main () { return 0; }' > conftest.c
+     bfd_cv_build_exeext=
+     ${CC_FOR_BUILD} -o conftest conftest.c 1>&5 2>&5
+     for file in conftest.*; do
+       case $file in
+       *.c | *.o | *.obj | *.ilk | *.pdb) ;;
+       *) bfd_cv_build_exeext=`echo $file | sed -e s/conftest//` ;;
+       esac
+     done
+     rm -f conftest*
+     test x"${bfd_cv_build_exeext}" = x && bfd_cv_build_exeext=no])
+  EXEEXT_FOR_BUILD=""
+  test x"${bfd_cv_build_exeext}" != xno && EXEEXT_FOR_BUILD=${bfd_cv_build_exeext}
+fi
+AC_SUBST(EXEEXT_FOR_BUILD)])dnl