diff --git a/.depend b/.depend
index 2e7da09b25e7..1a177e29bc9e 100644
--- a/.depend
+++ b/.depend
@@ -4189,6 +4189,7 @@ middle_end/closure/closure.cmo : \
     typing/env.cmi \
     lambda/debuginfo.cmi \
     middle_end/convert_primitives.cmi \
+    utils/config.cmi \
     middle_end/compilenv.cmi \
     utils/clflags.cmi \
     middle_end/clambda_primitives.cmi \
@@ -4211,6 +4212,7 @@ middle_end/closure/closure.cmx : \
     typing/env.cmx \
     lambda/debuginfo.cmx \
     middle_end/convert_primitives.cmx \
+    utils/config.cmx \
     middle_end/compilenv.cmx \
     utils/clflags.cmx \
     middle_end/clambda_primitives.cmx \
diff --git a/Makefile b/Makefile
index 71d41cd2d65a..fbb36a496c29 100644
--- a/Makefile
+++ b/Makefile
@@ -1284,11 +1284,10 @@ runtime/caml/jumptbl.h : runtime/caml/instruct.h
 	sed -n -e '/^  /s/ \([A-Z]\)/ \&\&lbl_\1/gp' \
 	       -e '/^}/q' > $@
 
-# These are provided as a temporary shim to allow cross-compilation systems
-# to supply a host C compiler and different flags and a linking macro.
-SAK_CC ?= $(CC)
-SAK_CFLAGS ?= $(OC_CFLAGS) $(CFLAGS) $(OC_CPPFLAGS) $(CPPFLAGS)
-SAK_LINK ?= $(MKEXE_VIA_CC)
+SAK_CC ?= $(CC_FOR_BUILD)
+SAK_CFLAGS ?=\
+  $(OC_CFLAGS) $(CFLAGS_FOR_BUILD) $(OC_CPPFLAGS) $(CPPFLAGS_FOR_BUILD)
+SAK_LINK ?= $(SAK_CC) $(SAK_CFLAGS) $(OUTPUTEXE)$(1) $(2)
 
 $(SAK): runtime/sak.$(O)
 	$(V_MKEXE)$(call SAK_LINK,$@,$^)
@@ -2733,6 +2732,11 @@ endif
 
 include .depend
 
+# Include the cross-compiler recipes only when relevant
+ifneq "$(HOST)" "$(TARGET)"
+include Makefile.cross
+endif
+
 Makefile.config Makefile.build_config: config.status
 config.status:
 	@echo "Please refer to the installation instructions:"
diff --git a/Makefile.config.in b/Makefile.config.in
index 559738f6ed05..b91634efb696 100644
--- a/Makefile.config.in
+++ b/Makefile.config.in
@@ -65,11 +65,13 @@ LIBTOOL = $(TOP_BUILDDIR)/libtool
 ### Which C compiler to use
 TOOLPREF=@ac_tool_prefix@
 CC=@CC@
+CC_FOR_BUILD=@CC_FOR_BUILD@
 
 CC_HAS_DEBUG_PREFIX_MAP=@cc_has_debug_prefix_map@
 AS_HAS_DEBUG_PREFIX_MAP=@as_has_debug_prefix_map@
 
 LDFLAGS?=@LDFLAGS@
+LDFLAGS_FOR_BUILD=@LDFLAGS_FOR_BUILD@
 
 ### How to invoke the C preprocessor through the C compiler
 CPP=@CPP@
@@ -160,7 +162,9 @@ UNIX_OR_WIN32=@unix_or_win32@
 INSTALL_SOURCE_ARTIFACTS=@install_source_artifacts@
 
 CFLAGS=@CFLAGS@
+CFLAGS_FOR_BUILD=@CFLAGS_FOR_BUILD@
 CPPFLAGS=@CPPFLAGS@
+CPPFLAGS_FOR_BUILD=@CPPFLAGS_FOR_BUILD@
 OCAMLC_CFLAGS=@ocamlc_cflags@
 
 OCAMLC_CPPFLAGS=@ocamlc_cppflags@
@@ -181,6 +185,7 @@ OCAMLOPT_CFLAGS=@ocamlc_cflags@
 OCAMLOPT_CPPFLAGS=@ocamlc_cppflags@
 NATIVECCLIBS=@cclibs@
 SYSTHREAD_SUPPORT=@systhread_support@
+STRIP=@STRIP@
 PACKLD=@PACKLD@$(EMPTY)
 CCOMPTYPE=@ccomptype@
 TOOLCHAIN=@toolchain@
diff --git a/Makefile.cross b/Makefile.cross
new file mode 100644
index 000000000000..b993783d2fc9
--- /dev/null
+++ b/Makefile.cross
@@ -0,0 +1,83 @@
+#**************************************************************************
+#*                                                                        *
+#*                                 OCaml                                  *
+#*                                                                        *
+#*                          Samuel Hym, Tarides                           *
+#*                                                                        *
+#*   Copyright 2024 Tarides                                               *
+#*                                                                        *
+#*   All rights reserved.  This file is distributed under the terms of    *
+#*   the GNU Lesser General Public License version 2.1, with the          *
+#*   special exception on linking described in the file LICENSE.          *
+#*                                                                        *
+#**************************************************************************
+
+# Recipes to build a cross-compiler (_not_ cross-compiling the compiler), aka
+# generating code that will run on `target`, assuming that a non-cross OCaml
+# compiler (so targetting our build machine) of the same version is available in
+# $PATH
+
+# We assume no zstd for the cross-compiler (ie no requirement on zstd for the
+# target)
+# Still the cross-compiler will run on host, not target. And as a consequence of
+# the rules linking it, the cross-compilers will be linked with the _build_
+# version of libcomprmarsh, so we still must discover the flags to link with
+# libzstd if it was set up in the non-cross compiler, so we rely on the
+# pkg-config command to get the linking flags for zstd
+PKG_CONFIG := pkg-config
+# This is used only once, so it doesn't have to be much lazier
+NATIVE_ZSTD_LIBS=ZSTD_LIBS="$(shell $(PKG_CONFIG) --libs libzstd)"
+# As the libcomprmarsh built by the C cross compiler will not be linked in, we
+# can build an empty one
+NO_ZSTD=libcomprmarsh_OBJECTS=
+
+CROSS_OVERRIDES=OCAMLRUN=ocamlrun NEW_OCAMLRUN=ocamlrun \
+  BOOT_OCAMLLEX=ocamllex OCAMLYACC=ocamlyacc
+CROSS_COMPILER_OVERRIDES=$(CROSS_OVERRIDES) CAMLC=ocamlc CAMLOPT=ocamlopt \
+  BEST_OCAMLC=ocamlc BEST_OCAMLOPT=ocamlopt BEST_OCAMLLEX=ocamllex
+
+INSTALL_OVERRIDES=build_ocamldoc=false WITH_DEBUGGER=
+
+# Freestanding target custom options
+ifeq "$(SYSTEM)" "none"
+RUNTIME_BUILD_OVERRIDES=runtime_PROGRAMS=
+INSTALL_OVERRIDES += runtime_PROGRAMS=`which ocamlrun` \
+  runtime_BYTECODE_STATIC_LIBRARIES=runtime/ld.conf
+else
+RUNTIME_BUILD_OVERRIDES=
+endif
+
+cross.opt:
+	$(MAKE) runtime-all $(NO_ZSTD) $(RUNTIME_BUILD_OVERRIDES)
+	$(MAKE) ocamlc ocamlopt $(TOOLS_BYTECODE_TARGETS) expunge \
+	  $(CROSS_COMPILER_OVERRIDES)
+	$(MAKE) library $(CROSS_OVERRIDES)
+ifneq "$(SYSTEM)" "none"
+	$(MAKE) ocamlyacc $(CROSS_OVERRIDES)
+	$(MAKE) ocamllex $(CROSS_COMPILER_OVERRIDES)
+endif
+	$(MAKE) ocaml $(CROSS_COMPILER_OVERRIDES)
+	$(MAKE) -C otherlibs all $(CROSS_OVERRIDES)
+	# Opt
+	$(MAKE) runtimeopt $(NO_ZSTD)
+	$(MAKE) ocamlc.opt ocamlopt.opt $(TOOLS_NATIVE_TARGETS) \
+	  $(NO_ZSTD) $(CROSS_COMPILER_OVERRIDES) $(NATIVE_ZSTD_LIBS)
+	$(MAKE) libraryopt $(NO_ZSTD) $(CROSS_OVERRIDES)
+	$(MAKE) otherlibrariesopt ocamltoolsopt $(NO_ZSTD) $(CROSS_OVERRIDES)
+	$(MAKE) tools-allopt.opt $(NO_ZSTD) $(CROSS_COMPILER_OVERRIDES)
+
+.PHONY: cross-install
+cross-install:
+	# dummy files
+	touch \
+	  $(addprefix toplevel/, \
+	    $(foreach ext,cmi cmt cmti cmx, native/nat__dummy__.$(ext)) \
+	      all__dummy__.cmx topstart.o native/tophooks.cmi)
+	$(LN) `which ocamlyacc` yacc/ocamlyacc.opt$(EXE)
+	$(LN) `which ocamllex` lex/ocamllex.opt$(EXE)
+ifeq "$(SYSTEM)" "none"
+	$(LN) `which ocamlyacc` yacc/ocamlyacc$(EXE)
+	$(LN) `which ocamllex` lex/ocamllex$(EXE)
+endif
+	# Real installation
+	$(MAKE) install $(INSTALL_OVERRIDES) OCAMLRUN=ocamlrun
diff --git a/aclocal.m4 b/aclocal.m4
index cb73385dda20..caafaa63c777 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -30,6 +30,7 @@ m4_include([build-aux/ax_check_compile_flag.m4])
 
 # Macros from the autoconf macro archive
 m4_include([build-aux/ax_func_which_gethostbyname_r.m4])
+m4_include([build-aux/ax_prog_cc_for_build.m4])
 m4_include([build-aux/ax_pthread.m4])
 
 # OCaml version
@@ -414,27 +415,27 @@ EOF
   OCAML_CC_RESTORE_VARIABLES
 ])
 
-AC_DEFUN([OCAML_HOST_IS_EXECUTABLE], [
-  AC_MSG_CHECKING([whether host executables can be run in the build])
+AC_DEFUN([OCAML_TARGET_IS_EXECUTABLE], [
+  AC_MSG_CHECKING([whether target executables can be run in the build])
   old_cross_compiling="$cross_compiling"
   cross_compiling='no'
   AC_RUN_IFELSE(
     [AC_LANG_SOURCE([[int main (void) {return 0;}]])],
     [AC_MSG_RESULT([yes])
-    host_runnable=true],
+    target_runnable=true],
     [AC_MSG_RESULT([no])
-    host_runnable=false],
+    target_runnable=false],
     # autoconf displays a warning if this parameter is missing, but
     # cross-compilation mode was disabled above.
     [assert=false])
   cross_compiling="$old_cross_compiling"
 ])
 
-# This is AC_RUN_IFELSE but taking $host_runnable into account (i.e. if the
+# This is AC_RUN_IFELSE but taking $target_runnable into account (i.e. if the
 # program can be run, then it is run)
 AC_DEFUN([OCAML_RUN_IFELSE], [
   old_cross_compiling="$cross_compiling"
-  AS_IF([test "x$host_runnable" = 'xtrue'], [cross_compiling='no'])
+  AS_IF([test "x$target_runnable" = 'xtrue'], [cross_compiling='no'])
   AC_RUN_IFELSE([$1],[$2],[$3],[$4])
   cross_compiling="$old_cross_compiling"
 ])
diff --git a/asmcomp/amd64/emit.mlp b/asmcomp/amd64/emit.mlp
index 619ce9c3c595..19f896c1ac51 100644
--- a/asmcomp/amd64/emit.mlp
+++ b/asmcomp/amd64/emit.mlp
@@ -1079,7 +1079,7 @@ let end_assembly() =
     D.size frametable (ConstSub (ConstThis, ConstLabel frametable))
   end;
 
-  if system = S_linux then
+  if system = S_linux || system = S_unknown then
     (* Mark stack as non-executable, PR#4564 *)
     D.section [".note.GNU-stack"] (Some "") [ "%progbits" ];
 
diff --git a/asmcomp/arm64/emit.mlp b/asmcomp/arm64/emit.mlp
index 1816f8c34537..41769e4f9347 100644
--- a/asmcomp/arm64/emit.mlp
+++ b/asmcomp/arm64/emit.mlp
@@ -1217,7 +1217,7 @@ let end_assembly () =
   emit_symbol_type emit_symbol lbl "object";
   emit_symbol_size lbl;
   begin match Config.system with
-  | "linux" ->
+  | "linux" | "none" ->
       (* Mark stack as non-executable *)
       `	.section	.note.GNU-stack,\"\",%progbits\n`
   | _ -> ()
diff --git a/asmcomp/x86_proc.ml b/asmcomp/x86_proc.ml
index b7abe4d3d1ca..540ee4864c18 100644
--- a/asmcomp/x86_proc.ml
+++ b/asmcomp/x86_proc.ml
@@ -27,6 +27,7 @@ type system =
   | S_freebsd
   | S_netbsd
   | S_openbsd
+  | S_none
 
   | S_unknown
 
@@ -43,6 +44,7 @@ let system = match Config.system with
   | "freebsd" -> S_freebsd
   | "netbsd" -> S_netbsd
   | "openbsd" -> S_openbsd
+  | "none" -> S_none
 
   | _ -> S_unknown
 
diff --git a/asmcomp/x86_proc.mli b/asmcomp/x86_proc.mli
index c7f9a5e59e13..002efff96878 100644
--- a/asmcomp/x86_proc.mli
+++ b/asmcomp/x86_proc.mli
@@ -69,6 +69,7 @@ type system =
   | S_freebsd
   | S_netbsd
   | S_openbsd
+  | S_none
 
   | S_unknown
 
diff --git a/boot/ocamlc b/boot/ocamlc
index ee406942e06d..aa35ace69ea6 100755
Binary files a/boot/ocamlc and b/boot/ocamlc differ
diff --git a/build-aux/ax_prog_cc_for_build.m4 b/build-aux/ax_prog_cc_for_build.m4
new file mode 100644
index 000000000000..1db8d73f9667
--- /dev/null
+++ b/build-aux/ax_prog_cc_for_build.m4
@@ -0,0 +1,155 @@
+# ===========================================================================
+#   https://www.gnu.org/software/autoconf-archive/ax_prog_cc_for_build.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_PROG_CC_FOR_BUILD
+#
+# DESCRIPTION
+#
+#   This macro searches for a C compiler that generates native executables,
+#   that is a C compiler that surely is not a cross-compiler. This can be
+#   useful if you have to generate source code at compile-time like for
+#   example GCC does.
+#
+#   The macro sets the CC_FOR_BUILD and CPP_FOR_BUILD macros to anything
+#   needed to compile or link (CC_FOR_BUILD) and preprocess (CPP_FOR_BUILD).
+#   The value of these variables can be overridden by the user by specifying
+#   a compiler with an environment variable (like you do for standard CC).
+#
+#   It also sets BUILD_EXEEXT and BUILD_OBJEXT to the executable and object
+#   file extensions for the build platform, and GCC_FOR_BUILD to `yes' if
+#   the compiler we found is GCC. All these variables but GCC_FOR_BUILD are
+#   substituted in the Makefile.
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Paolo Bonzini <bonzini@gnu.org>
+#
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved. This file is offered as-is, without any
+#   warranty.
+
+#serial 21
+
+AU_ALIAS([AC_PROG_CC_FOR_BUILD], [AX_PROG_CC_FOR_BUILD])
+AC_DEFUN([AX_PROG_CC_FOR_BUILD], [dnl
+AC_REQUIRE([AC_PROG_CC])dnl
+AC_REQUIRE([AC_PROG_CPP])dnl
+AC_REQUIRE([AC_CANONICAL_BUILD])dnl
+
+dnl Use the standard macros, but make them use other variable names
+dnl
+pushdef([ac_cv_prog_CPP], ac_cv_build_prog_CPP)dnl
+pushdef([ac_cv_prog_cc_c89], ac_cv_build_prog_cc_c89)dnl
+pushdef([ac_cv_prog_cc_c99], ac_cv_build_prog_cc_c99)dnl
+pushdef([ac_cv_prog_cc_c11], ac_cv_build_prog_cc_c11)dnl
+pushdef([ac_cv_prog_gcc], ac_cv_build_prog_gcc)dnl
+pushdef([ac_cv_prog_cc_works], ac_cv_build_prog_cc_works)dnl
+pushdef([ac_cv_prog_cc_cross], ac_cv_build_prog_cc_cross)dnl
+pushdef([ac_cv_prog_cc_g], ac_cv_build_prog_cc_g)dnl
+pushdef([ac_cv_c_compiler_gnu], ac_cv_build_c_compiler_gnu)dnl
+pushdef([ac_cv_exeext], ac_cv_build_exeext)dnl
+pushdef([ac_cv_objext], ac_cv_build_objext)dnl
+pushdef([ac_exeext], ac_build_exeext)dnl
+pushdef([ac_objext], ac_build_objext)dnl
+pushdef([CC], CC_FOR_BUILD)dnl
+pushdef([CPP], CPP_FOR_BUILD)dnl
+pushdef([GCC], GCC_FOR_BUILD)dnl
+pushdef([CFLAGS], CFLAGS_FOR_BUILD)dnl
+pushdef([CPPFLAGS], CPPFLAGS_FOR_BUILD)dnl
+pushdef([EXEEXT], BUILD_EXEEXT)dnl
+pushdef([LDFLAGS], LDFLAGS_FOR_BUILD)dnl
+pushdef([OBJEXT], BUILD_OBJEXT)dnl
+pushdef([host], build)dnl
+pushdef([host_alias], build_alias)dnl
+pushdef([host_cpu], build_cpu)dnl
+pushdef([host_vendor], build_vendor)dnl
+pushdef([host_os], build_os)dnl
+pushdef([ac_cv_host], ac_cv_build)dnl
+pushdef([ac_cv_host_alias], ac_cv_build_alias)dnl
+pushdef([ac_cv_host_cpu], ac_cv_build_cpu)dnl
+pushdef([ac_cv_host_vendor], ac_cv_build_vendor)dnl
+pushdef([ac_cv_host_os], ac_cv_build_os)dnl
+pushdef([ac_tool_prefix], ac_build_tool_prefix)dnl
+pushdef([am_cv_CC_dependencies_compiler_type], am_cv_build_CC_dependencies_compiler_type)dnl
+pushdef([am_cv_prog_cc_c_o], am_cv_build_prog_cc_c_o)dnl
+pushdef([cross_compiling], cross_compiling_build)dnl
+
+cross_compiling_build=no
+
+ac_build_tool_prefix=
+AS_IF([test -n "$build"],      [ac_build_tool_prefix="$build-"],
+      [test -n "$build_alias"],[ac_build_tool_prefix="$build_alias-"])
+
+AC_LANG_PUSH([C])
+
+dnl The pushdef([ac_cv_c_compiler_gnu], ...) currently does not cover
+dnl the use of this variable in _AC_LANG_COMPILER_GNU called by
+dnl AC_PROG_CC. Unset this cache variable temporarily as a workaround.
+was_set_c_compiler_gnu=${[ac_cv_c_compiler_gnu]+y}
+AS_IF([test ${was_set_c_compiler_gnu}],
+    [saved_c_compiler_gnu=$[ac_cv_c_compiler_gnu]
+    AS_UNSET([[ac_cv_c_compiler_gnu]])])
+
+AC_PROG_CC
+
+dnl Restore ac_cv_c_compiler_gnu
+AS_IF([test ${was_set_c_compiler_gnu}],
+  [[ac_cv_c_compiler_gnu]=$[saved_c_compiler_gnu]])
+
+_AC_COMPILER_EXEEXT
+_AC_COMPILER_OBJEXT
+AC_PROG_CPP
+
+dnl Restore the old definitions
+dnl
+popdef([cross_compiling])dnl
+popdef([am_cv_prog_cc_c_o])dnl
+popdef([am_cv_CC_dependencies_compiler_type])dnl
+popdef([ac_tool_prefix])dnl
+popdef([ac_cv_host_os])dnl
+popdef([ac_cv_host_vendor])dnl
+popdef([ac_cv_host_cpu])dnl
+popdef([ac_cv_host_alias])dnl
+popdef([ac_cv_host])dnl
+popdef([host_os])dnl
+popdef([host_vendor])dnl
+popdef([host_cpu])dnl
+popdef([host_alias])dnl
+popdef([host])dnl
+popdef([OBJEXT])dnl
+popdef([LDFLAGS])dnl
+popdef([EXEEXT])dnl
+popdef([CPPFLAGS])dnl
+popdef([CFLAGS])dnl
+popdef([GCC])dnl
+popdef([CPP])dnl
+popdef([CC])dnl
+popdef([ac_objext])dnl
+popdef([ac_exeext])dnl
+popdef([ac_cv_objext])dnl
+popdef([ac_cv_exeext])dnl
+popdef([ac_cv_c_compiler_gnu])dnl
+popdef([ac_cv_prog_cc_g])dnl
+popdef([ac_cv_prog_cc_cross])dnl
+popdef([ac_cv_prog_cc_works])dnl
+popdef([ac_cv_prog_cc_c89])dnl
+popdef([ac_cv_prog_gcc])dnl
+popdef([ac_cv_prog_CPP])dnl
+
+dnl restore global variables ac_ext, ac_cpp, ac_compile,
+dnl ac_link, ac_compiler_gnu (dependant on the current
+dnl language after popping):
+AC_LANG_POP([C])
+
+dnl Finally, set Makefile variables
+dnl
+AC_SUBST(BUILD_EXEEXT)dnl
+AC_SUBST(BUILD_OBJEXT)dnl
+AC_SUBST([CFLAGS_FOR_BUILD])dnl
+AC_SUBST([CPPFLAGS_FOR_BUILD])dnl
+AC_SUBST([LDFLAGS_FOR_BUILD])dnl
+])
diff --git a/configure b/configure
index 6dc7cc751737..8ca1b2fe2cce 100755
--- a/configure
+++ b/configure
@@ -730,6 +730,14 @@ INSTALL_DATA
 INSTALL_SCRIPT
 INSTALL_PROGRAM
 flexlink
+LDFLAGS_FOR_BUILD
+CPPFLAGS_FOR_BUILD
+CFLAGS_FOR_BUILD
+BUILD_OBJEXT
+BUILD_EXEEXT
+CPP_FOR_BUILD
+ac_ct_CC_FOR_BUILD
+CC_FOR_BUILD
 CPP
 ac_ct_DEP_CC
 DEP_CC
@@ -890,6 +898,7 @@ ocamlsrcdir
 systhread_support
 native_cppflags
 native_cflags
+target_os_type
 system
 model
 arch64
@@ -3436,6 +3445,7 @@ LINEAR_MAGIC_NUMBER=Caml1999L034
 
 
 
+
 
 
  # TODO: rename this variable
@@ -3619,6 +3629,25 @@ IFS=$ac_save_IFS
 case $host_os in *\ *) host_os=`echo "$host_os" | sed 's/ /-/g'`;; esac
 
 
+# Allow "ocaml" as target OS for freestanding compiler by temporarily rewriting
+# the target OS to "none" to generate the canonical target
+real_target_alias="$target_alias"
+case $target_alias in #(
+  *-*-*-ocaml) :
+    ac_save_IFS=$IFS
+    IFS='-'
+    set x $target_alias
+    target_alias="$2-$3-none"
+    IFS=$ac_save_IFS ;; #(
+  *-*-ocaml) :
+    ac_save_IFS=$IFS
+    IFS='-'
+    set x $target_alias
+    target_alias="$2-none"
+    IFS=$ac_save_IFS ;; #(
+  *) :
+     ;;
+esac
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking target system type" >&5
 printf %s "checking target system type... " >&6; }
 if test ${ac_cv_target+y}
@@ -3659,6 +3688,20 @@ test -n "$target_alias" &&
   test "$program_prefix$program_suffix$program_transform_name" = \
     NONENONEs,x,x, &&
   program_prefix=${target_alias}-
+target_alias="$real_target_alias"
+
+# Override cross_compiling and ac_tool_prefix variables since the C toolchain is
+# used to generate target code when building a cross compiler
+if test x"$build" = x"$target"
+then :
+  cross_compiling=no
+else $as_nop
+  cross_compiling=yes
+fi
+if test -n "$target_alias"
+then :
+  ac_tool_prefix=$target_alias-
+fi
 
 # Ensure that AC_CONFIG_LINKS will either create symlinks which are compatible
 # with native Windows (i.e. NTFS symlinks, not WSL or Cygwin-emulated ones) or
@@ -3674,7 +3717,7 @@ esac
 
 # Systems that are known not to work, even in bytecode only.
 
-case $host in #(
+case $target in #(
   *-pc-windows) :
     as_fn_error 69 "the MSVC compiler is not supported currently" "$LINENO" 5 ;; #(
   i386-*-solaris*) :
@@ -3687,7 +3730,7 @@ esac
 
 # MSVC special case
 
-case $host in #(
+case $target in #(
   *-pc-windows) :
     CC=cl
     ccomptype=msvc
@@ -4173,11 +4216,10 @@ fi
 # Initialization of libtool
 # Allow the MSVC linker to be found even if ld isn't installed.
 # User-specified LD still takes precedence.
-if test -n "$ac_tool_prefix"; then
-  for ac_prog in ld link
-  do
-    # Extract the first word of "$ac_tool_prefix$ac_prog", so it can be a program name with args.
-set dummy $ac_tool_prefix$ac_prog; ac_word=$2
+for ac_prog in ld link
+do
+  # Extract the first word of "$target_alias-$ac_prog", so it can be a program name with args.
+set dummy $target_alias-$ac_prog; ac_word=$2
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
 printf %s "checking for $ac_word... " >&6; }
 if test ${ac_cv_prog_LD+y}
@@ -4198,7 +4240,7 @@ do
   esac
     for ac_exec_ext in '' $ac_executable_extensions; do
   if as_fn_executable_p "$as_dir$ac_word$ac_exec_ext"; then
-    ac_cv_prog_LD="$ac_tool_prefix$ac_prog"
+    ac_cv_prog_LD="$target_alias-$ac_prog"
     printf "%s\n" "$as_me:${as_lineno-$LINENO}: found $as_dir$ac_word$ac_exec_ext" >&5
     break 2
   fi
@@ -4218,12 +4260,12 @@ printf "%s\n" "no" >&6; }
 fi
 
 
-    test -n "$LD" && break
-  done
-fi
+  test -n "$LD" && break
+done
 if test -z "$LD"; then
-  ac_ct_LD=$LD
-  for ac_prog in ld link
+  if test "$build" = "$target"; then
+    ac_ct_LD=$LD
+    for ac_prog in ld link
 do
   # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
@@ -4270,27 +4312,25 @@ fi
   test -n "$ac_ct_LD" && break
 done
 
-  if test "x$ac_ct_LD" = x; then
-    LD=""
-  else
-    case $cross_compiling:$ac_tool_warned in
-yes:)
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
-printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
-ac_tool_warned=yes ;;
-esac
     LD=$ac_ct_LD
+  else
+    LD=""
   fi
 fi
 
+# libtool will detect a build-to-host C toolchain but when building an OCaml
+# cross compiler we need the C toolchain to build the target runtime so we
+# temporarily define host* values as macros for target* values so that the
+# proper toolchain is configured. Note that host=target unless we are building a
+# cross compiler so this is transparent for the usual use case.
 # libtool expects host_os=mingw for native Windows
 # Also, it has been observed that, on some platforms (e.g. msvc) LT_INIT
 # alters the CFLAGS variable, so we save its value before calling the macro
 # and restore it after the call
-old_host_os=$host_os
-if test x"$host_os" = "xwindows"
+old_host_os=$target_os
+if test x"$target_os" = "xwindows"
 then :
-  host_os=mingw
+  target_os=mingw
 fi
 saved_CFLAGS="$CFLAGS"
 
@@ -4495,8 +4535,8 @@ fi
   else
     case $cross_compiling:$ac_tool_warned in
 yes:)
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
-printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with target triplet" >&5
+printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with target triplet" >&2;}
 ac_tool_warned=yes ;;
 esac
     CC=$ac_ct_CC
@@ -4715,8 +4755,8 @@ done
   else
     case $cross_compiling:$ac_tool_warned in
 yes:)
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
-printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with target triplet" >&5
+printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with target triplet" >&2;}
 ac_tool_warned=yes ;;
 esac
     CC=$ac_ct_CC
@@ -4817,8 +4857,8 @@ fi
   else
     case $cross_compiling:$ac_tool_warned in
 yes:)
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
-printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with target triplet" >&5
+printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with target triplet" >&2;}
 ac_tool_warned=yes ;;
 esac
     CC=$ac_ct_CC
@@ -5052,7 +5092,7 @@ printf "%s\n" "$ac_try_echo"; } >&5
 	{ { printf "%s\n" "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
 printf "%s\n" "$as_me: error: in \`$ac_pwd':" >&2;}
 as_fn_error 77 "cannot run C compiled programs.
-If you meant to cross compile, use \`--host'.
+If you meant to cross compile, use \`--target'.
 See \`config.log' for more details" "$LINENO" 5; }
     fi
   fi
@@ -5720,7 +5760,7 @@ if test yes = "$GCC"; then
   # Check if gcc -print-prog-name=ld gives a path.
   { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for ld used by $CC" >&5
 printf %s "checking for ld used by $CC... " >&6; }
-  case $host in
+  case $target in
   *-*-mingw*)
     # gcc leaves a trailing carriage return, which upsets mingw
     ac_prog=`($CC -print-prog-name=ld) 2>&5 | tr -d '\015'` ;;
@@ -5832,7 +5872,7 @@ else $as_nop
   lt_cv_path_NM=$NM
 else
   lt_nm_to_check=${ac_tool_prefix}nm
-  if test -n "$ac_tool_prefix" && test "$build" = "$host"; then
+  if test -n "$ac_tool_prefix" && test "$build" = "$target"; then
     lt_nm_to_check="$lt_nm_to_check nm"
   fi
   for lt_tmp_nm in $lt_nm_to_check; do
@@ -5987,8 +6027,8 @@ done
   else
     case $cross_compiling:$ac_tool_warned in
 yes:)
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
-printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with target triplet" >&5
+printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with target triplet" >&2;}
 ac_tool_warned=yes ;;
 esac
     DUMPBIN=$ac_ct_DUMPBIN
@@ -6232,13 +6272,13 @@ esac
 
 
 
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking how to convert $build file names to $host format" >&5
-printf %s "checking how to convert $build file names to $host format... " >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking how to convert $build file names to $target format" >&5
+printf %s "checking how to convert $build file names to $target format... " >&6; }
 if test ${lt_cv_to_host_file_cmd+y}
 then :
   printf %s "(cached) " >&6
 else $as_nop
-  case $host in
+  case $target in
   *-*-mingw* )
     case $build in
       *-*-mingw* ) # actually msys
@@ -6288,7 +6328,7 @@ then :
 else $as_nop
   #assume ordinary cross tools, or native build.
 lt_cv_to_tool_file_cmd=func_convert_file_noop
-case $host in
+case $target in
   *-*-mingw* )
     case $build in
       *-*-mingw* ) # actually msys
@@ -6324,7 +6364,7 @@ case $reload_flag in
 *) reload_flag=" $reload_flag" ;;
 esac
 reload_cmds='$LD$reload_flag -o $output$reload_objs'
-case $host_os in
+case $target_os in
   cygwin* | mingw* | pw32* | cegcc*)
     if test yes != "$GCC"; then
       reload_cmds=false
@@ -6439,8 +6479,8 @@ fi
   else
     case $cross_compiling:$ac_tool_warned in
 yes:)
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
-printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with target triplet" >&5
+printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with target triplet" >&2;}
 ac_tool_warned=yes ;;
 esac
     OBJDUMP=$ac_ct_OBJDUMP
@@ -6479,7 +6519,7 @@ lt_cv_deplibs_check_method='unknown'
 # If you have 'file' or equivalent on your system and you're not sure
 # whether 'pass_all' will *always* work, you probably want this one.
 
-case $host_os in
+case $target_os in
 aix[4-9]*)
   lt_cv_deplibs_check_method=pass_all
   ;;
@@ -6526,7 +6566,7 @@ darwin* | rhapsody*)
 
 freebsd* | dragonfly*)
   if echo __ELF__ | $CC -E - | $GREP __ELF__ > /dev/null; then
-    case $host_cpu in
+    case $target_cpu in
     i*86 )
       # Not sure whether the presence of OpenBSD here was a mistake.
       # Let's accept both of them until this is cleared up.
@@ -6546,7 +6586,7 @@ haiku*)
 
 hpux10.20* | hpux11*)
   lt_cv_file_magic_cmd=/usr/bin/file
-  case $host_cpu in
+  case $target_cpu in
   ia64*)
     lt_cv_deplibs_check_method='file_magic (s[0-9][0-9][0-9]|ELF-[0-9][0-9]) shared object file - IA64'
     lt_cv_file_magic_test_file=/usr/lib/hpux32/libc.so
@@ -6625,7 +6665,7 @@ sysv5* | sco3.2v5* | sco5v6* | unixware* | OpenUNIX* | sysv4*uw2*)
   ;;
 
 sysv4 | sysv4.3*)
-  case $host_vendor in
+  case $target_vendor in
   motorola)
     lt_cv_deplibs_check_method='file_magic ELF [0-9][0-9]*-bit [ML]SB (shared object|dynamic lib) M[0-9][0-9]* Version [0-9]'
     lt_cv_file_magic_test_file=`echo /usr/lib/libc.so*`
@@ -6665,8 +6705,8 @@ printf "%s\n" "$lt_cv_deplibs_check_method" >&6; }
 
 file_magic_glob=
 want_nocaseglob=no
-if test "$build" = "$host"; then
-  case $host_os in
+if test "$build" = "$target"; then
+  case $target_os in
   mingw* | pw32*)
     if ( shopt | grep nocaseglob ) >/dev/null 2>&1; then
       want_nocaseglob=yes
@@ -6794,8 +6834,8 @@ fi
   else
     case $cross_compiling:$ac_tool_warned in
 yes:)
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
-printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with target triplet" >&5
+printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with target triplet" >&2;}
 ac_tool_warned=yes ;;
 esac
     DLLTOOL=$ac_ct_DLLTOOL
@@ -6823,7 +6863,7 @@ then :
 else $as_nop
   lt_cv_sharedlib_from_linklib_cmd='unknown'
 
-case $host_os in
+case $target_os in
 cygwin* | mingw* | pw32* | cegcc*)
   # two different shell functions defined in ltmain.sh;
   # decide which one to use based on capabilities of $DLLTOOL
@@ -6957,8 +6997,8 @@ done
   else
     case $cross_compiling:$ac_tool_warned in
 yes:)
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
-printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with target triplet" >&5
+printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with target triplet" >&2;}
 ac_tool_warned=yes ;;
 esac
     AR=$ac_ct_AR
@@ -7130,8 +7170,8 @@ fi
   else
     case $cross_compiling:$ac_tool_warned in
 yes:)
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
-printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with target triplet" >&5
+printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with target triplet" >&2;}
 ac_tool_warned=yes ;;
 esac
     STRIP=$ac_ct_STRIP
@@ -7239,8 +7279,8 @@ fi
   else
     case $cross_compiling:$ac_tool_warned in
 yes:)
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
-printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with target triplet" >&5
+printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with target triplet" >&2;}
 ac_tool_warned=yes ;;
 esac
     RANLIB=$ac_ct_RANLIB
@@ -7262,7 +7302,7 @@ old_postinstall_cmds='chmod 644 $oldlib'
 old_postuninstall_cmds=
 
 if test -n "$RANLIB"; then
-  case $host_os in
+  case $target_os in
   bitrig* | openbsd*)
     old_postinstall_cmds="$old_postinstall_cmds~\$RANLIB -t \$tool_oldlib"
     ;;
@@ -7273,7 +7313,7 @@ if test -n "$RANLIB"; then
   old_archive_cmds="$old_archive_cmds~\$RANLIB \$tool_oldlib"
 fi
 
-case $host_os in
+case $target_os in
   darwin*)
     lock_old_archive_extraction=yes ;;
   *)
@@ -7393,7 +7433,7 @@ symcode='[BCDEGRST]'
 sympat='\([_A-Za-z][_A-Za-z0-9]*\)'
 
 # Define system-specific variables.
-case $host_os in
+case $target_os in
 aix*)
   symcode='[BCDT]'
   ;;
@@ -7401,7 +7441,7 @@ cygwin* | mingw* | pw32* | cegcc*)
   symcode='[ABCDGISTW]'
   ;;
 hpux*)
-  if test ia64 = "$host_cpu"; then
+  if test ia64 = "$target_cpu"; then
     symcode='[ABCDEGRST]'
   fi
   ;;
@@ -7816,7 +7856,7 @@ func_cc_basename ()
         *) break;;
       esac
     done
-    func_cc_basename_result=`$ECHO "$cc_temp" | $SED "s%.*/%%; s%^$host_alias-%%"`
+    func_cc_basename_result=`$ECHO "$cc_temp" | $SED "s%.*/%%; s%^$target_alias-%%"`
 }
 
 # Check whether --enable-libtool-lock was given.
@@ -7829,7 +7869,7 @@ test no = "$enable_libtool_lock" || enable_libtool_lock=yes
 
 # Some flags need to be propagated to the compiler or linker for good
 # libtool support.
-case $host in
+case $target in
 ia64-*-hpux*)
   # Find out what ABI is being produced by ac_compile, and set mode
   # options accordingly.
@@ -7940,7 +7980,7 @@ s390*-*linux*|s390*-*tpf*|sparc*-*linux*)
   test $ac_status = 0; }; then
     case `/usr/bin/file conftest.o` in
       *32-bit*)
-	case $host in
+	case $target in
 	  x86_64-*kfreebsd*-gnu)
 	    LD="${LD-ld} -m elf_i386_fbsd"
 	    ;;
@@ -7969,7 +8009,7 @@ s390*-*linux*|s390*-*tpf*|sparc*-*linux*)
 	esac
 	;;
       *64-bit*)
-	case $host in
+	case $target in
 	  x86_64-*kfreebsd*-gnu)
 	    LD="${LD-ld} -m elf_x86_64_fbsd"
 	    ;;
@@ -8057,7 +8097,7 @@ printf "%s\n" "$lt_cv_cc_needs_belf" >&6; }
     *64-bit*)
       case $lt_cv_prog_gnu_ld in
       yes*)
-        case $host in
+        case $target in
         i?86-*-solaris*|x86_64-*-solaris*)
           LD="${LD-ld} -m elf_x86_64"
           ;;
@@ -8177,8 +8217,8 @@ fi
   else
     case $cross_compiling:$ac_tool_warned in
 yes:)
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
-printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with target triplet" >&5
+printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with target triplet" >&2;}
 ac_tool_warned=yes ;;
 esac
     MANIFEST_TOOL=$ac_ct_MANIFEST_TOOL
@@ -8214,7 +8254,7 @@ fi
 
 
 
-  case $host_os in
+  case $target_os in
     rhapsody* | darwin*)
     if test -n "$ac_tool_prefix"; then
   # Extract the first word of "${ac_tool_prefix}dsymutil", so it can be a program name with args.
@@ -8308,8 +8348,8 @@ fi
   else
     case $cross_compiling:$ac_tool_warned in
 yes:)
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
-printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with target triplet" >&5
+printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with target triplet" >&2;}
 ac_tool_warned=yes ;;
 esac
     DSYMUTIL=$ac_ct_DSYMUTIL
@@ -8410,8 +8450,8 @@ fi
   else
     case $cross_compiling:$ac_tool_warned in
 yes:)
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
-printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with target triplet" >&5
+printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with target triplet" >&2;}
 ac_tool_warned=yes ;;
 esac
     NMEDIT=$ac_ct_NMEDIT
@@ -8512,8 +8552,8 @@ fi
   else
     case $cross_compiling:$ac_tool_warned in
 yes:)
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
-printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with target triplet" >&5
+printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with target triplet" >&2;}
 ac_tool_warned=yes ;;
 esac
     LIPO=$ac_ct_LIPO
@@ -8614,8 +8654,8 @@ fi
   else
     case $cross_compiling:$ac_tool_warned in
 yes:)
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
-printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with target triplet" >&5
+printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with target triplet" >&2;}
 ac_tool_warned=yes ;;
 esac
     OTOOL=$ac_ct_OTOOL
@@ -8716,8 +8756,8 @@ fi
   else
     case $cross_compiling:$ac_tool_warned in
 yes:)
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
-printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with target triplet" >&5
+printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with target triplet" >&2;}
 ac_tool_warned=yes ;;
 esac
     OTOOL64=$ac_ct_OTOOL64
@@ -8859,7 +8899,7 @@ _LT_EOF
 fi
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $lt_cv_ld_force_load" >&5
 printf "%s\n" "$lt_cv_ld_force_load" >&6; }
-    case $host_os in
+    case $target_os in
     rhapsody* | darwin1.[012])
       _lt_dar_allow_undefined='$wl-undefined ${wl}suppress' ;;
     darwin1.*)
@@ -8868,7 +8908,7 @@ printf "%s\n" "$lt_cv_ld_force_load" >&6; }
       # if running on 10.5 or later, the deployment target defaults
       # to the OS version, if on x86, and 10.4, the deployment
       # target defaults to 10.4. Don't you love it?
-      case ${MACOSX_DEPLOYMENT_TARGET-10.0},$host in
+      case ${MACOSX_DEPLOYMENT_TARGET-10.0},$target in
 	10.0,*86*-darwin8*|10.0,*-darwin[91]*)
 	  _lt_dar_allow_undefined='$wl-undefined ${wl}dynamic_lookup' ;;
 	10.[012][,.]*)
@@ -9107,7 +9147,7 @@ fi
 
 
   shared_archive_member_spec=
-case $host,$enable_shared in
+case $target,$enable_shared in
 power*-*-aix[5-9]*,yes)
   { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking which variant of shared library versioning to provide" >&5
 printf %s "checking which variant of shared library versioning to provide... " >&6; }
@@ -9246,7 +9286,7 @@ printf "%s\n" "#define LT_OBJDIR \"$lt_cv_objdir/\"" >>confdefs.h
 
 
 
-case $host_os in
+case $target_os in
 aix3*)
   # AIX sometimes has problems with the GCC collect2 program.  For some
   # reason, if we set the COLLECT_NAMES environment variable, the problems
@@ -9558,10 +9598,10 @@ lt_prog_compiler_static=
     lt_prog_compiler_wl='-Wl,'
     lt_prog_compiler_static='-static'
 
-    case $host_os in
+    case $target_os in
       aix*)
       # All AIX code is PIC.
-      if test ia64 = "$host_cpu"; then
+      if test ia64 = "$target_cpu"; then
 	# AIX 5 now supports IA64 processor
 	lt_prog_compiler_static='-Bstatic'
       fi
@@ -9569,7 +9609,7 @@ lt_prog_compiler_static=
       ;;
 
     amigaos*)
-      case $host_cpu in
+      case $target_cpu in
       powerpc)
             # see comment about AmigaOS4 .so support
             lt_prog_compiler_pic='-fPIC'
@@ -9593,7 +9633,7 @@ lt_prog_compiler_static=
       # Although the cygwin gcc ignores -fPIC, still need this for old-style
       # (--disable-auto-import) libraries
       lt_prog_compiler_pic='-DDLL_EXPORT'
-      case $host_os in
+      case $target_os in
       os2*)
 	lt_prog_compiler_static='$wl-static'
 	;;
@@ -9616,7 +9656,7 @@ lt_prog_compiler_static=
       # PIC is the default for 64-bit PA HP-UX, but not for 32-bit
       # PA HP-UX.  On IA64 HP-UX, PIC is the default but the pic flag
       # sets the default TLS model and affects inlining.
-      case $host_cpu in
+      case $target_cpu in
       hppa*64*)
 	# +Z the default
 	;;
@@ -9665,10 +9705,10 @@ lt_prog_compiler_static=
     esac
   else
     # PORTME Check for flag to pass linker flags through the system compiler.
-    case $host_os in
+    case $target_os in
     aix*)
       lt_prog_compiler_wl='-Wl,'
-      if test ia64 = "$host_cpu"; then
+      if test ia64 = "$target_cpu"; then
 	# AIX 5 now supports IA64 processor
 	lt_prog_compiler_static='-Bstatic'
       else
@@ -9694,7 +9734,7 @@ lt_prog_compiler_static=
       # This hack is so that the source file can tell whether it is being
       # built for inclusion in a dll (and should export symbols for example).
       lt_prog_compiler_pic='-DDLL_EXPORT'
-      case $host_os in
+      case $target_os in
       os2*)
 	lt_prog_compiler_static='$wl-static'
 	;;
@@ -9705,7 +9745,7 @@ lt_prog_compiler_static=
       lt_prog_compiler_wl='-Wl,'
       # PIC is the default for IA64 HP-UX and 64-bit HP-UX, but
       # not for PA HP-UX.
-      case $host_cpu in
+      case $target_cpu in
       hppa*64*|ia64*)
 	# +Z the default
 	;;
@@ -9881,7 +9921,7 @@ lt_prog_compiler_static=
     esac
   fi
 
-case $host_os in
+case $target_os in
   # For platforms that do not support PIC, -DPIC is meaningless:
   *djgpp*)
     lt_prog_compiler_pic=
@@ -10196,7 +10236,7 @@ printf %s "checking whether the $compiler linker ($LD) supports shared libraries
   # Exclude shared library initialization/finalization symbols.
   extract_expsyms_cmds=
 
-  case $host_os in
+  case $target_os in
   cygwin* | mingw* | pw32* | cegcc*)
     # FIXME: the MSVC++ port hasn't been tested in a loooong time
     # When not using gcc, we currently assume that we are using
@@ -10223,7 +10263,7 @@ printf %s "checking whether the $compiler linker ($LD) supports shared libraries
   # that we're better off using the native interface for both.
   lt_use_gnu_ld_interface=no
   if test yes = "$with_gnu_ld"; then
-    case $host_os in
+    case $target_os in
       aix*)
 	# The AIX port of GNU ld has always aspired to compatibility
 	# with the native linker.  However, as the warning in the GNU ld
@@ -10271,10 +10311,10 @@ printf %s "checking whether the $compiler linker ($LD) supports shared libraries
     esac
 
     # See if GNU ld supports shared libraries.
-    case $host_os in
+    case $target_os in
     aix[3-9]*)
       # On AIX/PPC, the GNU linker is very broken
-      if test ia64 != "$host_cpu"; then
+      if test ia64 != "$target_cpu"; then
 	ld_shlibs=no
 	cat <<_LT_EOF 1>&2
 
@@ -10290,7 +10330,7 @@ _LT_EOF
       ;;
 
     amigaos*)
-      case $host_cpu in
+      case $target_cpu in
       powerpc)
             # see comment about AmigaOS4 .so support
             archive_cmds='$CC -shared $libobjs $deplibs $compiler_flags $wl-soname $wl$soname -o $lib'
@@ -10392,7 +10432,7 @@ _LT_EOF
 
     gnu* | linux* | tpf* | k*bsd*-gnu | kopensolaris*-gnu)
       tmp_diet=no
-      if test linux-dietlibc = "$host_os"; then
+      if test linux-dietlibc = "$target_os"; then
 	case $cc_basename in
 	  diet\ *) tmp_diet=yes;;	# linux-dietlibc with static linking (!diet-dyn)
 	esac
@@ -10402,7 +10442,7 @@ _LT_EOF
       then
 	tmp_addflag=' $pic_flag'
 	tmp_sharedflag='-shared'
-	case $cc_basename,$host_cpu in
+	case $cc_basename,$target_cpu in
         pgcc*)				# Portland Group C compiler
 	  whole_archive_flag_spec='$wl--whole-archive`for conv in $convenience\"\"; do test  -n \"$conv\" && new_convenience=\"$new_convenience,$conv\"; done; func_echo_all \"$new_convenience\"` $wl--no-whole-archive'
 	  tmp_addflag=' $pic_flag'
@@ -10556,7 +10596,7 @@ _LT_EOF
     fi
   else
     # PORTME fill in a description of your system's linker (not GNU ld)
-    case $host_os in
+    case $target_os in
     aix3*)
       allow_undefined_flag=unsupported
       always_export_symbols=yes
@@ -10572,7 +10612,7 @@ _LT_EOF
       ;;
 
     aix[4-9]*)
-      if test ia64 = "$host_cpu"; then
+      if test ia64 = "$target_cpu"; then
 	# On IA64, the linker does run time linking by default, so we don't
 	# have to do anything special.
 	aix_use_runtimelinking=no
@@ -10609,7 +10649,7 @@ _LT_EOF
 	#            lib.a(lib.so.V) shared, rtl:no
 	# "svr4,*"   lib.so.V(shr.o) shared, rtl:yes, for executables
 	#            lib.a           static archive
-	case $host_os in aix4.[23]|aix4.[23].*|aix[5-9]*)
+	case $target_os in aix4.[23]|aix4.[23].*|aix[5-9]*)
 	  for ld_flag in $LDFLAGS; do
 	  if (test x-brtl = "x$ld_flag" || test x-Wl,-brtl = "x$ld_flag"); then
 	    aix_use_runtimelinking=yes
@@ -10652,7 +10692,7 @@ _LT_EOF
       esac
 
       if test yes = "$GCC"; then
-	case $host_os in aix4.[012]|aix4.[012].*)
+	case $target_os in aix4.[012]|aix4.[012].*)
 	# We only want to do this on AIX 4.2 and lower, the check
 	# below for broken collect2 doesn't work under 4.3+
 	  collect2name=`$CC -print-prog-name=collect2`
@@ -10684,7 +10724,7 @@ _LT_EOF
 	shared_flag_svr4='-shared $wl-G'
       else
 	# not using gcc
-	if test ia64 = "$host_cpu"; then
+	if test ia64 = "$target_cpu"; then
 	# VisualAge C++, Version 5.5 for AIX 5L for IA-64, Beta 3 Release
 	# chokes on -Wl,-G. The following line is correct:
 	  shared_flag='-G'
@@ -10757,7 +10797,7 @@ fi
         hardcode_libdir_flag_spec='$wl-blibpath:$libdir:'"$aix_libpath"
         archive_expsym_cmds='$CC -o $output_objdir/$soname $libobjs $deplibs $wl'$no_entry_flag' $compiler_flags `if test -n "$allow_undefined_flag"; then func_echo_all "$wl$allow_undefined_flag"; else :; fi` $wl'$exp_sym_flag:\$export_symbols' '$shared_flag
       else
-	if test ia64 = "$host_cpu"; then
+	if test ia64 = "$target_cpu"; then
 	  hardcode_libdir_flag_spec='$wl-R $libdir:/usr/lib:/lib'
 	  allow_undefined_flag="-z nodefs"
 	  archive_expsym_cmds="\$CC $shared_flag"' -o $output_objdir/$soname $libobjs $deplibs '"\$wl$no_entry_flag"' $compiler_flags $wl$allow_undefined_flag '"\$wl$exp_sym_flag:\$export_symbols"
@@ -10841,7 +10881,7 @@ fi
       ;;
 
     amigaos*)
-      case $host_cpu in
+      case $target_cpu in
       powerpc)
             # see comment about AmigaOS4 .so support
             archive_cmds='$CC -shared $libobjs $deplibs $compiler_flags $wl-soname $wl$soname -o $lib'
@@ -11026,7 +11066,7 @@ fi
 
     hpux11*)
       if test yes,no = "$GCC,$with_gnu_ld"; then
-	case $host_cpu in
+	case $target_cpu in
 	hppa*64*)
 	  archive_cmds='$CC -shared $wl+h $wl$soname -o $lib $libobjs $deplibs $compiler_flags'
 	  ;;
@@ -11038,7 +11078,7 @@ fi
 	  ;;
 	esac
       else
-	case $host_cpu in
+	case $target_cpu in
 	hppa*64*)
 	  archive_cmds='$CC -b $wl+h $wl$soname -o $lib $libobjs $deplibs $compiler_flags'
 	  ;;
@@ -11094,7 +11134,7 @@ fi
 	hardcode_libdir_flag_spec='$wl+b $wl$libdir'
 	hardcode_libdir_separator=:
 
-	case $host_cpu in
+	case $target_cpu in
 	hppa*64*|ia64*)
 	  hardcode_direct=no
 	  hardcode_shlibpath_var=no
@@ -11119,8 +11159,8 @@ fi
 	# work, assume that -exports_file does not work either and
 	# implicitly export all symbols.
 	# This should be the same for all languages, so no per-tag cache variable.
-	{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether the $host_os linker accepts -exported_symbol" >&5
-printf %s "checking whether the $host_os linker accepts -exported_symbol... " >&6; }
+	{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether the $target_os linker accepts -exported_symbol" >&5
+printf %s "checking whether the $target_os linker accepts -exported_symbol... " >&6; }
 if test ${lt_cv_irix_exported_symbol+y}
 then :
   printf %s "(cached) " >&6
@@ -11293,7 +11333,7 @@ printf "%s\n" "$lt_cv_irix_exported_symbol" >&6; }
       fi
       hardcode_libdir_flag_spec='-R$libdir'
       hardcode_shlibpath_var=no
-      case $host_os in
+      case $target_os in
       solaris2.[0-5] | solaris2.[0-5].*) ;;
       *)
 	# The compiler driver will combine and reorder linker options,
@@ -11311,7 +11351,7 @@ printf "%s\n" "$lt_cv_irix_exported_symbol" >&6; }
       ;;
 
     sunos4*)
-      if test sequent = "$host_vendor"; then
+      if test sequent = "$target_vendor"; then
 	# Use $CC to link under sequent, because it throws in some extra .o
 	# files that make .init and .fini sections work.
 	archive_cmds='$CC -G $wl-h $soname -o $lib $libobjs $deplibs $compiler_flags'
@@ -11325,7 +11365,7 @@ printf "%s\n" "$lt_cv_irix_exported_symbol" >&6; }
       ;;
 
     sysv4)
-      case $host_vendor in
+      case $target_vendor in
 	sni)
 	  archive_cmds='$LD -G -h $soname -o $lib $libobjs $deplibs $linker_flags'
 	  hardcode_direct=yes # is this really true???
@@ -11414,8 +11454,8 @@ printf "%s\n" "$lt_cv_irix_exported_symbol" >&6; }
       ;;
     esac
 
-    if test sni = "$host_vendor"; then
-      case $host in
+    if test sni = "$target_vendor"; then
+      case $target in
       sysv4 | sysv4.2uw2* | sysv4.3* | sysv5*)
 	export_dynamic_flag_spec='$wl-Blargedynsym'
 	;;
@@ -11668,11 +11708,11 @@ esac
 printf %s "checking dynamic linker characteristics... " >&6; }
 
 if test yes = "$GCC"; then
-  case $host_os in
+  case $target_os in
     darwin*) lt_awk_arg='/^libraries:/,/LR/' ;;
     *) lt_awk_arg='/^libraries:/' ;;
   esac
-  case $host_os in
+  case $target_os in
     mingw* | cegcc*) lt_sed_strip_eq='s|=\([A-Za-z]:\)|\1|g' ;;
     *) lt_sed_strip_eq='s|=/|/|g' ;;
   esac
@@ -11730,7 +11770,7 @@ BEGIN {RS = " "; FS = "/|\n";} {
 }'`
   # AWK program above erroneously prepends '/' to C:/dos/paths
   # for these hosts.
-  case $host_os in
+  case $target_os in
     mingw* | cegcc*) lt_search_path_spec=`$ECHO "$lt_search_path_spec" |\
       $SED 's|/\([A-Za-z]:\)|\1|g'` ;;
   esac
@@ -11749,7 +11789,7 @@ finish_eval=
 shlibpath_var=
 shlibpath_overrides_runpath=unknown
 version_type=none
-dynamic_linker="$host_os ld.so"
+dynamic_linker="$target_os ld.so"
 sys_lib_dlsearch_path_spec="/lib /usr/lib"
 need_lib_prefix=unknown
 hardcode_into_libs=no
@@ -11760,7 +11800,7 @@ need_version=unknown
 
 
 
-case $host_os in
+case $target_os in
 aix3*)
   version_type=linux # correct to gnu/linux during the next big refactor
   library_names_spec='$libname$release$shared_ext$versuffix $libname.a'
@@ -11775,7 +11815,7 @@ aix[4-9]*)
   need_lib_prefix=no
   need_version=no
   hardcode_into_libs=yes
-  if test ia64 = "$host_cpu"; then
+  if test ia64 = "$target_cpu"; then
     # AIX 5 supports IA64
     library_names_spec='$libname$release$shared_ext$major $libname$release$shared_ext$versuffix $libname$shared_ext'
     shlibpath_var=LD_LIBRARY_PATH
@@ -11785,7 +11825,7 @@ aix[4-9]*)
     # the line '#! .'.  This would cause the generated library to
     # depend on '.', always an invalid library.  This was fixed in
     # development snapshots of GCC prior to 3.0.
-    case $host_os in
+    case $target_os in
       aix4 | aix4.[01] | aix4.[01].*)
       if { echo '#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 97)'
 	   echo ' yes '
@@ -11865,7 +11905,7 @@ aix[4-9]*)
   ;;
 
 amigaos*)
-  case $host_cpu in
+  case $target_cpu in
   powerpc)
     # Since July 2007 AmigaOS4 officially supports .so libraries.
     # When compiling the executable, add -use-dynld -Lsobjs: to the compileline.
@@ -11881,7 +11921,7 @@ amigaos*)
 
 beos*)
   library_names_spec='$libname$shared_ext'
-  dynamic_linker="$host_os ld.so"
+  dynamic_linker="$target_os ld.so"
   shlibpath_var=LIBRARY_PATH
   ;;
 
@@ -11924,7 +11964,7 @@ cygwin* | mingw* | pw32* | cegcc*)
        $RM \$dlpath'
     shlibpath_overrides_runpath=yes
 
-    case $host_os in
+    case $target_os in
     cygwin*)
       # Cygwin DLLs use 'cyg' prefix rather than 'lib'
       soname_spec='`echo $libname | sed -e 's/^lib/cyg/'``echo $release | $SED -e 's/[.]/-/g'`$versuffix$shared_ext'
@@ -12010,7 +12050,7 @@ cygwin* | mingw* | pw32* | cegcc*)
   ;;
 
 darwin* | rhapsody*)
-  dynamic_linker="$host_os dyld"
+  dynamic_linker="$target_os dyld"
   version_type=darwin
   need_lib_prefix=no
   need_version=no
@@ -12039,7 +12079,7 @@ freebsd* | dragonfly*)
   if test -x /usr/bin/objformat; then
     objformat=`/usr/bin/objformat`
   else
-    case $host_os in
+    case $target_os in
     freebsd[23].*) objformat=aout ;;
     *) objformat=elf ;;
     esac
@@ -12058,7 +12098,7 @@ freebsd* | dragonfly*)
       ;;
   esac
   shlibpath_var=LD_LIBRARY_PATH
-  case $host_os in
+  case $target_os in
   freebsd2.*)
     shlibpath_overrides_runpath=yes
     ;;
@@ -12082,7 +12122,7 @@ haiku*)
   version_type=linux # correct to gnu/linux during the next big refactor
   need_lib_prefix=no
   need_version=no
-  dynamic_linker="$host_os runtime_loader"
+  dynamic_linker="$target_os runtime_loader"
   library_names_spec='$libname$release$shared_ext$versuffix $libname$release$shared_ext$major $libname$shared_ext'
   soname_spec='$libname$release$shared_ext$major'
   shlibpath_var=LIBRARY_PATH
@@ -12097,11 +12137,11 @@ hpux9* | hpux10* | hpux11*)
   version_type=sunos
   need_lib_prefix=no
   need_version=no
-  case $host_cpu in
+  case $target_cpu in
   ia64*)
     shrext_cmds='.so'
     hardcode_into_libs=yes
-    dynamic_linker="$host_os dld.so"
+    dynamic_linker="$target_os dld.so"
     shlibpath_var=LD_LIBRARY_PATH
     shlibpath_overrides_runpath=yes # Unless +noenvvar is specified.
     library_names_spec='$libname$release$shared_ext$versuffix $libname$release$shared_ext$major $libname$shared_ext'
@@ -12117,7 +12157,7 @@ hpux9* | hpux10* | hpux11*)
   hppa*64*)
     shrext_cmds='.sl'
     hardcode_into_libs=yes
-    dynamic_linker="$host_os dld.sl"
+    dynamic_linker="$target_os dld.sl"
     shlibpath_var=LD_LIBRARY_PATH # How should we handle SHLIB_PATH
     shlibpath_overrides_runpath=yes # Unless +noenvvar is specified.
     library_names_spec='$libname$release$shared_ext$versuffix $libname$release$shared_ext$major $libname$shared_ext'
@@ -12127,7 +12167,7 @@ hpux9* | hpux10* | hpux11*)
     ;;
   *)
     shrext_cmds='.sl'
-    dynamic_linker="$host_os dld.sl"
+    dynamic_linker="$target_os dld.sl"
     shlibpath_var=SHLIB_PATH
     shlibpath_overrides_runpath=no # +s is required to enable SHLIB_PATH
     library_names_spec='$libname$release$shared_ext$versuffix $libname$release$shared_ext$major $libname$shared_ext'
@@ -12153,7 +12193,7 @@ interix[3-9]*)
   ;;
 
 irix5* | irix6* | nonstopux*)
-  case $host_os in
+  case $target_os in
     nonstopux*) version_type=nonstopux ;;
     *)
 	if test yes = "$lt_cv_prog_gnu_ld"; then
@@ -12166,7 +12206,7 @@ irix5* | irix6* | nonstopux*)
   need_version=no
   soname_spec='$libname$release$shared_ext$major'
   library_names_spec='$libname$release$shared_ext$versuffix $libname$release$shared_ext$major $libname$release$shared_ext $libname$shared_ext'
-  case $host_os in
+  case $target_os in
   irix5* | nonstopux*)
     libsuff= shlibsuff=
     ;;
@@ -12426,7 +12466,7 @@ sysv4 | sysv4.3*)
   library_names_spec='$libname$release$shared_ext$versuffix $libname$release$shared_ext$major $libname$shared_ext'
   soname_spec='$libname$release$shared_ext$major'
   shlibpath_var=LD_LIBRARY_PATH
-  case $host_vendor in
+  case $target_vendor in
     sni)
       shlibpath_overrides_runpath=no
       need_lib_prefix=no
@@ -12466,7 +12506,7 @@ sysv5* | sco3.2v5* | sco5v6* | unixware* | OpenUNIX* | sysv4*uw2*)
     sys_lib_search_path_spec='/usr/local/lib /usr/gnu/lib /usr/ccs/lib /usr/lib /lib'
   else
     sys_lib_search_path_spec='/usr/ccs/lib /usr/lib'
-    case $host_os in
+    case $target_os in
       sco3.2v5*)
         sys_lib_search_path_spec="$sys_lib_search_path_spec /lib"
 	;;
@@ -12670,7 +12710,7 @@ else
   lt_cv_dlopen=no
   lt_cv_dlopen_libs=
 
-  case $host_os in
+  case $target_os in
   beos*)
     lt_cv_dlopen=load_add_on
     lt_cv_dlopen_libs=
@@ -13205,7 +13245,7 @@ if test -n "$STRIP" && $STRIP -V 2>&1 | $GREP "GNU strip" >/dev/null; then
 printf "%s\n" "yes" >&6; }
 else
 # FIXME - insert some real tests, host_os isn't really good enough
-  case $host_os in
+  case $target_os in
   darwin*)
     if test -n "$STRIP"; then
       striplib="$STRIP -x"
@@ -13247,7 +13287,7 @@ printf %s "checking whether to build shared libraries... " >&6; }
 
   # On AIX, shared libraries and static libraries use the same namespace, and
   # are all built from PIC.
-  case $host_os in
+  case $target_os in
   aix3*)
     test yes = "$enable_shared" && enable_static=no
     if test -n "$RANLIB"; then
@@ -13257,7 +13297,7 @@ printf %s "checking whether to build shared libraries... " >&6; }
     ;;
 
   aix[4-9]*)
-    if test ia64 != "$host_cpu"; then
+    if test ia64 != "$target_cpu"; then
       case $enable_shared,$with_aix_soname,$aix_use_runtimelinking in
       yes,aix,yes) ;;			# shared object as lib.so file only
       yes,svr4,*) ;;			# shared object as lib.so archive member only
@@ -13311,7 +13351,7 @@ CC=$lt_save_CC
 
 
 CFLAGS="$saved_CFLAGS"
-host_os=$old_host_os
+target_os=$old_host_os
 
 case $host in #(
   sparc-sun-solaris*) :
@@ -13455,7 +13495,7 @@ else $as_nop
 fi ;;
 esac
 
-case $host in #(
+case $target in #(
   # In config/Makefile.mingw*, we had:
   # TARGET=i686-w64-mingw32 and x86_64-w64-mingw32
   # TOOLPREF=$(TARGET)-
@@ -13467,7 +13507,7 @@ case $host in #(
       mkexe_via_cc_extra_cmd=' && $(call MERGEMANIFESTEXE,$(1))'
       libext=lib
       AR=""
-      if test "$host_cpu" = "x86_64"
+      if test "$target_cpu" = "x86_64"
 then :
   machine="-machine:AMD64 "
 else $as_nop
@@ -13678,8 +13718,8 @@ printf "%s\n" "$ocaml_cc_vendor" >&6; }
 ## In cross-compilation mode, can we run executables produced?
 # At the moment, it's required, but the fact is used in C99 function detection
 
-  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether host executables can be run in the build" >&5
-printf %s "checking whether host executables can be run in the build... " >&6; }
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether target executables can be run in the build" >&5
+printf %s "checking whether target executables can be run in the build... " >&6; }
   old_cross_compiling="$cross_compiling"
   cross_compiling='no'
   if test "$cross_compiling" = yes
@@ -13696,11 +13736,11 @@ if ac_fn_c_try_run "$LINENO"
 then :
   { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
 printf "%s\n" "yes" >&6; }
-    host_runnable=true
+    target_runnable=true
 else $as_nop
   { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
 printf "%s\n" "no" >&6; }
-    host_runnable=false
+    target_runnable=false
 fi
 rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
   conftest.$ac_objext conftest.beam conftest.$ac_ext
@@ -13759,23 +13799,28 @@ case lt_cv_ar_at_file in #(
     ar_supports_response_files=true ;;
 esac
 
-# Libraries to build depending on the host
+# Libraries to build depending on the target
 
 case $host in #(
   *-*-mingw32*|*-pc-windows) :
-    unix_or_win32="win32"
     ln='cp -pf'
+    ocamlsrcdir="$(LC_ALL=C.UTF-8 cygpath -w -- "$ocamlsrcdir")" ;; #(
+  *) :
+    ln='ln -sf' ;;
+esac
+
+case $target in #(
+  *-*-mingw32*|*-pc-windows) :
+    unix_or_win32="win32" # or should it be tested against host?
     ocamltest_libunix="Some false"
-    ocamlsrcdir="$(LC_ALL=C.UTF-8 cygpath -w -- "$ocamlsrcdir")"
     ocamlyacc_wstr_module="yacc/wstr" ;; #(
   *) :
     unix_or_win32="unix"
-  ln='ln -sf'
   ocamltest_libunix="Some true"
   ocamlyacc_wstr_module="" ;;
 esac
 
-case $host in #(
+case $target in #(
   *-*-cygwin*|*-*-mingw32*|*-pc-windows) :
     exeext=".exe" ;; #(
   *) :
@@ -13840,7 +13885,7 @@ shebangscripts=false
 launch_method='exe'
 if test "x$interpval" = "xyes"
 then :
-  case $host in #(
+  case $target in #(
   *-cygwin) :
     # Cygwin supports shebangs, which we use for the compiler itself, but
       # partially for legacy, and partially so that executables can be easily
@@ -13875,85 +13920,1270 @@ then :
   cross_compiler=false
 else $as_nop
   cross_compiler=true
+    # We require a non-cross-compiler of the same version
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking the version of the installed OCaml compiler" >&5
+printf %s "checking the version of the installed OCaml compiler... " >&6; }
+    already_installed_version=`ocamlc -vnum`
+    if test x"5.2.0" = x"$already_installed_version"
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: compatible (5.2.0)" >&5
+printf "%s\n" "compatible (5.2.0)" >&6; }
+else $as_nop
+  as_fn_error $? "incompatible (5.2.0 vs $already_installed_version)" "$LINENO" 5
+fi
 fi
 
-# Checks for programs
+if test x"$build" = x"$target" -o x"$target_runnable" = xtrue
+then :
+  CC_FOR_BUILD='$(CC)'
+    CFLAGS_FOR_BUILD='$(CFLAGS)'
+    CPPFLAGS_FOR_BUILD='$(CPPFLAGS)'
+    LDFLAGS_FOR_BUILD='$(LDFLAGS)'
+else $as_nop
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: detecting the C toolchain for build" >&5
+printf "%s\n" "$as_me: detecting the C toolchain for build" >&6;}
 
-## Check for the C compiler: done by libtool
-## AC_PROG_CC
 
-## Check for C99 support: done by libtool
-## AC_PROG_CC_C99
+cross_compiling_build=no
 
-## Determine which flags to use for the C compiler
+ac_build_tool_prefix=
+if test -n "$build"
+then :
+  ac_build_tool_prefix="$build-"
+elif test -n "$build_alias"
+then :
+  ac_build_tool_prefix="$build_alias-"
+fi
 
-case $ocaml_cc_vendor in #(
-  xlc-*) :
-    outputobj='-o '
-    warn_error_flag=''
-    cc_warnings='-qflag=i:i' ;; #(
-  # all warnings enabled
-  sunc-*) :
-    outputobj='-o '; cc_warnings="" ;; #(
-  msvc-*) :
-    outputobj='-Fo'
-    warn_error_flag='-WX'
-    cc_warnings='' ;; #(
-  *) :
-    outputobj='-o '
-  warn_error_flag='-Werror'
-  cc_warnings="-Wall -Wint-conversion -Wstrict-prototypes \
--Wold-style-definition -Wundef" ;;
-esac
+ac_ext=c
+ac_cpp='$CPP_FOR_BUILD $CPPFLAGS_FOR_BUILD'
+ac_compile='$CC_FOR_BUILD -c $CFLAGS_FOR_BUILD $CPPFLAGS_FOR_BUILD conftest.$ac_ext >&5'
+ac_link='$CC_FOR_BUILD -o conftest$ac_build_exeext $CFLAGS_FOR_BUILD $CPPFLAGS_FOR_BUILD $LDFLAGS_FOR_BUILD conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_build_c_compiler_gnu
 
-# Use -Wold-style-declaration if supported
-as_CACHEVAR=`printf "%s\n" "ax_cv_check_cflags_$warn_error_flag_-Wold-style-declaration" | $as_tr_sh`
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether C compiler accepts -Wold-style-declaration" >&5
-printf %s "checking whether C compiler accepts -Wold-style-declaration... " >&6; }
-if eval test \${$as_CACHEVAR+y}
+
+was_set_c_compiler_gnu=${ac_cv_c_compiler_gnu+y}
+if test ${was_set_c_compiler_gnu}
+then :
+  saved_c_compiler_gnu=$ac_cv_c_compiler_gnu
+    { ac_cv_c_compiler_gnu=; unset ac_cv_c_compiler_gnu;}
+fi
+
+ac_ext=c
+ac_cpp='$CPP_FOR_BUILD $CPPFLAGS_FOR_BUILD'
+ac_compile='$CC_FOR_BUILD -c $CFLAGS_FOR_BUILD $CPPFLAGS_FOR_BUILD conftest.$ac_ext >&5'
+ac_link='$CC_FOR_BUILD -o conftest$ac_build_exeext $CFLAGS_FOR_BUILD $CPPFLAGS_FOR_BUILD $LDFLAGS_FOR_BUILD conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_build_c_compiler_gnu
+if test -n "$ac_build_tool_prefix"; then
+  # Extract the first word of "${ac_tool_prefix}gcc", so it can be a program name with args.
+set dummy ${ac_build_tool_prefix}gcc; ac_word=$2
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+printf %s "checking for $ac_word... " >&6; }
+if test ${ac_cv_prog_CC_FOR_BUILD+y}
 then :
   printf %s "(cached) " >&6
 else $as_nop
+  if test -n "$CC_FOR_BUILD"; then
+  ac_cv_prog_CC_FOR_BUILD="$CC_FOR_BUILD" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  case $as_dir in #(((
+    '') as_dir=./ ;;
+    */) ;;
+    *) as_dir=$as_dir/ ;;
+  esac
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir$ac_word$ac_exec_ext"; then
+    ac_cv_prog_CC_FOR_BUILD="${ac_build_tool_prefix}gcc"
+    printf "%s\n" "$as_me:${as_lineno-$LINENO}: found $as_dir$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
 
-  ax_check_save_flags=$CFLAGS
-  CFLAGS="$CFLAGS $warn_error_flag -Wold-style-declaration"
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
+fi
+fi
+CC_FOR_BUILD=$ac_cv_prog_CC_FOR_BUILD
+if test -n "$CC_FOR_BUILD"; then
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $CC_FOR_BUILD" >&5
+printf "%s\n" "$CC_FOR_BUILD" >&6; }
+else
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+fi
 
-int
-main (void)
-{
 
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"
+fi
+if test -z "$ac_cv_prog_CC_FOR_BUILD"; then
+  ac_ct_CC_FOR_BUILD=$CC_FOR_BUILD
+  # Extract the first word of "gcc", so it can be a program name with args.
+set dummy gcc; ac_word=$2
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+printf %s "checking for $ac_word... " >&6; }
+if test ${ac_cv_prog_ac_ct_CC_FOR_BUILD+y}
 then :
-  eval "$as_CACHEVAR=yes"
+  printf %s "(cached) " >&6
 else $as_nop
-  eval "$as_CACHEVAR=no"
+  if test -n "$ac_ct_CC_FOR_BUILD"; then
+  ac_cv_prog_ac_ct_CC_FOR_BUILD="$ac_ct_CC_FOR_BUILD" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  case $as_dir in #(((
+    '') as_dir=./ ;;
+    */) ;;
+    *) as_dir=$as_dir/ ;;
+  esac
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir$ac_word$ac_exec_ext"; then
+    ac_cv_prog_ac_ct_CC_FOR_BUILD="gcc"
+    printf "%s\n" "$as_me:${as_lineno-$LINENO}: found $as_dir$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
-  CFLAGS=$ax_check_save_flags
 fi
-eval ac_res=\$$as_CACHEVAR
-	       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
-printf "%s\n" "$ac_res" >&6; }
-if eval test \"x\$"$as_CACHEVAR"\" = x"yes"
+ac_ct_CC_FOR_BUILD=$ac_cv_prog_ac_ct_CC_FOR_BUILD
+if test -n "$ac_ct_CC_FOR_BUILD"; then
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_ct_CC_FOR_BUILD" >&5
+printf "%s\n" "$ac_ct_CC_FOR_BUILD" >&6; }
+else
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+fi
+
+  if test "x$ac_ct_CC_FOR_BUILD" = x; then
+    CC_FOR_BUILD=""
+  else
+    case $cross_compiling_build:$ac_tool_warned in
+yes:)
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with build triplet" >&5
+printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with build triplet" >&2;}
+ac_tool_warned=yes ;;
+esac
+    CC_FOR_BUILD=$ac_ct_CC_FOR_BUILD
+  fi
+else
+  CC_FOR_BUILD="$ac_cv_prog_CC_FOR_BUILD"
+fi
+
+if test -z "$CC_FOR_BUILD"; then
+          if test -n "$ac_build_tool_prefix"; then
+    # Extract the first word of "${ac_tool_prefix}cc", so it can be a program name with args.
+set dummy ${ac_build_tool_prefix}cc; ac_word=$2
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+printf %s "checking for $ac_word... " >&6; }
+if test ${ac_cv_prog_CC_FOR_BUILD+y}
 then :
-  cc_warnings="$cc_warnings -Wold-style-declaration"
+  printf %s "(cached) " >&6
 else $as_nop
-  :
-fi
+  if test -n "$CC_FOR_BUILD"; then
+  ac_cv_prog_CC_FOR_BUILD="$CC_FOR_BUILD" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  case $as_dir in #(((
+    '') as_dir=./ ;;
+    */) ;;
+    *) as_dir=$as_dir/ ;;
+  esac
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir$ac_word$ac_exec_ext"; then
+    ac_cv_prog_CC_FOR_BUILD="${ac_build_tool_prefix}cc"
+    printf "%s\n" "$as_me:${as_lineno-$LINENO}: found $as_dir$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
 
+fi
+fi
+CC_FOR_BUILD=$ac_cv_prog_CC_FOR_BUILD
+if test -n "$CC_FOR_BUILD"; then
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $CC_FOR_BUILD" >&5
+printf "%s\n" "$CC_FOR_BUILD" >&6; }
+else
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+fi
 
-case $enable_warn_error,false in #(
-  yes,*|,true) :
-    cc_warnings="$cc_warnings $warn_error_flag" ;; #(
-  *) :
-     ;;
-esac
+
+  fi
+fi
+if test -z "$CC_FOR_BUILD"; then
+  # Extract the first word of "cc", so it can be a program name with args.
+set dummy cc; ac_word=$2
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+printf %s "checking for $ac_word... " >&6; }
+if test ${ac_cv_prog_CC_FOR_BUILD+y}
+then :
+  printf %s "(cached) " >&6
+else $as_nop
+  if test -n "$CC_FOR_BUILD"; then
+  ac_cv_prog_CC_FOR_BUILD="$CC_FOR_BUILD" # Let the user override the test.
+else
+  ac_prog_rejected=no
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  case $as_dir in #(((
+    '') as_dir=./ ;;
+    */) ;;
+    *) as_dir=$as_dir/ ;;
+  esac
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir$ac_word$ac_exec_ext"; then
+    if test "$as_dir$ac_word$ac_exec_ext" = "/usr/ucb/cc"; then
+       ac_prog_rejected=yes
+       continue
+     fi
+    ac_cv_prog_CC_FOR_BUILD="cc"
+    printf "%s\n" "$as_me:${as_lineno-$LINENO}: found $as_dir$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+if test $ac_prog_rejected = yes; then
+  # We found a bogon in the path, so make sure we never use it.
+  set dummy $ac_cv_prog_CC_FOR_BUILD
+  shift
+  if test $# != 0; then
+    # We chose a different compiler from the bogus one.
+    # However, it has the same basename, so the bogon will be chosen
+    # first if we set CC_FOR_BUILD to just the basename; use the full file name.
+    shift
+    ac_cv_prog_CC_FOR_BUILD="$as_dir$ac_word${1+' '}$@"
+  fi
+fi
+fi
+fi
+CC_FOR_BUILD=$ac_cv_prog_CC_FOR_BUILD
+if test -n "$CC_FOR_BUILD"; then
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $CC_FOR_BUILD" >&5
+printf "%s\n" "$CC_FOR_BUILD" >&6; }
+else
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+fi
+
+
+fi
+if test -z "$CC_FOR_BUILD"; then
+  if test -n "$ac_build_tool_prefix"; then
+  for ac_prog in cl.exe
+  do
+    # Extract the first word of "$ac_tool_prefix$ac_prog", so it can be a program name with args.
+set dummy $ac_build_tool_prefix$ac_prog; ac_word=$2
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+printf %s "checking for $ac_word... " >&6; }
+if test ${ac_cv_prog_CC_FOR_BUILD+y}
+then :
+  printf %s "(cached) " >&6
+else $as_nop
+  if test -n "$CC_FOR_BUILD"; then
+  ac_cv_prog_CC_FOR_BUILD="$CC_FOR_BUILD" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  case $as_dir in #(((
+    '') as_dir=./ ;;
+    */) ;;
+    *) as_dir=$as_dir/ ;;
+  esac
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir$ac_word$ac_exec_ext"; then
+    ac_cv_prog_CC_FOR_BUILD="$ac_build_tool_prefix$ac_prog"
+    printf "%s\n" "$as_me:${as_lineno-$LINENO}: found $as_dir$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+fi
+fi
+CC_FOR_BUILD=$ac_cv_prog_CC_FOR_BUILD
+if test -n "$CC_FOR_BUILD"; then
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $CC_FOR_BUILD" >&5
+printf "%s\n" "$CC_FOR_BUILD" >&6; }
+else
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+fi
+
+
+    test -n "$CC_FOR_BUILD" && break
+  done
+fi
+if test -z "$CC_FOR_BUILD"; then
+  ac_ct_CC_FOR_BUILD=$CC_FOR_BUILD
+  for ac_prog in cl.exe
+do
+  # Extract the first word of "$ac_prog", so it can be a program name with args.
+set dummy $ac_prog; ac_word=$2
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+printf %s "checking for $ac_word... " >&6; }
+if test ${ac_cv_prog_ac_ct_CC_FOR_BUILD+y}
+then :
+  printf %s "(cached) " >&6
+else $as_nop
+  if test -n "$ac_ct_CC_FOR_BUILD"; then
+  ac_cv_prog_ac_ct_CC_FOR_BUILD="$ac_ct_CC_FOR_BUILD" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  case $as_dir in #(((
+    '') as_dir=./ ;;
+    */) ;;
+    *) as_dir=$as_dir/ ;;
+  esac
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir$ac_word$ac_exec_ext"; then
+    ac_cv_prog_ac_ct_CC_FOR_BUILD="$ac_prog"
+    printf "%s\n" "$as_me:${as_lineno-$LINENO}: found $as_dir$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+fi
+fi
+ac_ct_CC_FOR_BUILD=$ac_cv_prog_ac_ct_CC_FOR_BUILD
+if test -n "$ac_ct_CC_FOR_BUILD"; then
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_ct_CC_FOR_BUILD" >&5
+printf "%s\n" "$ac_ct_CC_FOR_BUILD" >&6; }
+else
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+fi
+
+
+  test -n "$ac_ct_CC_FOR_BUILD" && break
+done
+
+  if test "x$ac_ct_CC_FOR_BUILD" = x; then
+    CC_FOR_BUILD=""
+  else
+    case $cross_compiling_build:$ac_tool_warned in
+yes:)
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with build triplet" >&5
+printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with build triplet" >&2;}
+ac_tool_warned=yes ;;
+esac
+    CC_FOR_BUILD=$ac_ct_CC_FOR_BUILD
+  fi
+fi
+
+fi
+if test -z "$CC_FOR_BUILD"; then
+  if test -n "$ac_build_tool_prefix"; then
+  # Extract the first word of "${ac_tool_prefix}clang", so it can be a program name with args.
+set dummy ${ac_build_tool_prefix}clang; ac_word=$2
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+printf %s "checking for $ac_word... " >&6; }
+if test ${ac_cv_prog_CC_FOR_BUILD+y}
+then :
+  printf %s "(cached) " >&6
+else $as_nop
+  if test -n "$CC_FOR_BUILD"; then
+  ac_cv_prog_CC_FOR_BUILD="$CC_FOR_BUILD" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  case $as_dir in #(((
+    '') as_dir=./ ;;
+    */) ;;
+    *) as_dir=$as_dir/ ;;
+  esac
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir$ac_word$ac_exec_ext"; then
+    ac_cv_prog_CC_FOR_BUILD="${ac_build_tool_prefix}clang"
+    printf "%s\n" "$as_me:${as_lineno-$LINENO}: found $as_dir$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+fi
+fi
+CC_FOR_BUILD=$ac_cv_prog_CC_FOR_BUILD
+if test -n "$CC_FOR_BUILD"; then
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $CC_FOR_BUILD" >&5
+printf "%s\n" "$CC_FOR_BUILD" >&6; }
+else
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+fi
+
+
+fi
+if test -z "$ac_cv_prog_CC_FOR_BUILD"; then
+  ac_ct_CC_FOR_BUILD=$CC_FOR_BUILD
+  # Extract the first word of "clang", so it can be a program name with args.
+set dummy clang; ac_word=$2
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+printf %s "checking for $ac_word... " >&6; }
+if test ${ac_cv_prog_ac_ct_CC_FOR_BUILD+y}
+then :
+  printf %s "(cached) " >&6
+else $as_nop
+  if test -n "$ac_ct_CC_FOR_BUILD"; then
+  ac_cv_prog_ac_ct_CC_FOR_BUILD="$ac_ct_CC_FOR_BUILD" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  case $as_dir in #(((
+    '') as_dir=./ ;;
+    */) ;;
+    *) as_dir=$as_dir/ ;;
+  esac
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir$ac_word$ac_exec_ext"; then
+    ac_cv_prog_ac_ct_CC_FOR_BUILD="clang"
+    printf "%s\n" "$as_me:${as_lineno-$LINENO}: found $as_dir$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+fi
+fi
+ac_ct_CC_FOR_BUILD=$ac_cv_prog_ac_ct_CC_FOR_BUILD
+if test -n "$ac_ct_CC_FOR_BUILD"; then
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_ct_CC_FOR_BUILD" >&5
+printf "%s\n" "$ac_ct_CC_FOR_BUILD" >&6; }
+else
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+fi
+
+  if test "x$ac_ct_CC_FOR_BUILD" = x; then
+    CC_FOR_BUILD=""
+  else
+    case $cross_compiling_build:$ac_tool_warned in
+yes:)
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with build triplet" >&5
+printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with build triplet" >&2;}
+ac_tool_warned=yes ;;
+esac
+    CC_FOR_BUILD=$ac_ct_CC_FOR_BUILD
+  fi
+else
+  CC_FOR_BUILD="$ac_cv_prog_CC_FOR_BUILD"
+fi
+
+fi
+
+
+test -z "$CC_FOR_BUILD" && { { printf "%s\n" "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+printf "%s\n" "$as_me: error: in \`$ac_pwd':" >&2;}
+as_fn_error $? "no acceptable C compiler found in \$PATH
+See \`config.log' for more details" "$LINENO" 5; }
+
+# Provide some information about the compiler.
+printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for C compiler version" >&5
+set X $ac_compile
+ac_compiler=$2
+for ac_option in --version -v -V -qversion -version; do
+  { { ac_try="$ac_compiler $ac_option >&5"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
+printf "%s\n" "$ac_try_echo"; } >&5
+  (eval "$ac_compiler $ac_option >&5") 2>conftest.err
+  ac_status=$?
+  if test -s conftest.err; then
+    sed '10a\
+... rest of stderr output deleted ...
+         10q' conftest.err >conftest.er1
+    cat conftest.er1 >&5
+  fi
+  rm -f conftest.er1 conftest.err
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+done
+
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether the compiler supports GNU C" >&5
+printf %s "checking whether the compiler supports GNU C... " >&6; }
+if test ${ac_cv_c_compiler_gnu+y}
+then :
+  printf %s "(cached) " >&6
+else $as_nop
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main (void)
+{
+#ifndef __GNUC__
+       choke me
+#endif
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"
+then :
+  ac_compiler_gnu=yes
+else $as_nop
+  ac_compiler_gnu=no
+fi
+rm -f core conftest.err conftest.$ac_build_objext conftest.beam conftest.$ac_ext
+ac_cv_c_compiler_gnu=$ac_compiler_gnu
+
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_c_compiler_gnu" >&5
+printf "%s\n" "$ac_cv_c_compiler_gnu" >&6; }
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+if test $ac_compiler_gnu = yes; then
+  GCC_FOR_BUILD=yes
+else
+  GCC_FOR_BUILD=
+fi
+ac_test_CFLAGS=${CFLAGS_FOR_BUILD+y}
+ac_save_CFLAGS=$CFLAGS_FOR_BUILD
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CC_FOR_BUILD accepts -g" >&5
+printf %s "checking whether $CC_FOR_BUILD accepts -g... " >&6; }
+if test ${ac_cv_build_prog_cc_g+y}
+then :
+  printf %s "(cached) " >&6
+else $as_nop
+  ac_save_c_werror_flag=$ac_c_werror_flag
+   ac_c_werror_flag=yes
+   ac_cv_build_prog_cc_g=no
+   CFLAGS_FOR_BUILD="-g"
+   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main (void)
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"
+then :
+  ac_cv_build_prog_cc_g=yes
+else $as_nop
+  CFLAGS_FOR_BUILD=""
+      cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main (void)
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"
+then :
+
+else $as_nop
+  ac_c_werror_flag=$ac_save_c_werror_flag
+	 CFLAGS_FOR_BUILD="-g"
+	 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main (void)
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"
+then :
+  ac_cv_build_prog_cc_g=yes
+fi
+rm -f core conftest.err conftest.$ac_build_objext conftest.beam conftest.$ac_ext
+fi
+rm -f core conftest.err conftest.$ac_build_objext conftest.beam conftest.$ac_ext
+fi
+rm -f core conftest.err conftest.$ac_build_objext conftest.beam conftest.$ac_ext
+   ac_c_werror_flag=$ac_save_c_werror_flag
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_build_prog_cc_g" >&5
+printf "%s\n" "$ac_cv_build_prog_cc_g" >&6; }
+if test $ac_test_CFLAGS; then
+  CFLAGS_FOR_BUILD=$ac_save_CFLAGS
+elif test $ac_cv_build_prog_cc_g = yes; then
+  if test "$GCC_FOR_BUILD" = yes; then
+    CFLAGS_FOR_BUILD="-g -O2"
+  else
+    CFLAGS_FOR_BUILD="-g"
+  fi
+else
+  if test "$GCC_FOR_BUILD" = yes; then
+    CFLAGS_FOR_BUILD="-O2"
+  else
+    CFLAGS_FOR_BUILD=
+  fi
+fi
+ac_prog_cc_stdc=no
+if test x$ac_prog_cc_stdc = xno
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $CC_FOR_BUILD option to enable C11 features" >&5
+printf %s "checking for $CC_FOR_BUILD option to enable C11 features... " >&6; }
+if test ${ac_cv_build_prog_cc_c11+y}
+then :
+  printf %s "(cached) " >&6
+else $as_nop
+  ac_cv_build_prog_cc_c11=no
+ac_save_CC=$CC_FOR_BUILD
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+$ac_c_conftest_c11_program
+_ACEOF
+for ac_arg in '' -std=gnu11
+do
+  CC_FOR_BUILD="$ac_save_CC $ac_arg"
+  if ac_fn_c_try_compile "$LINENO"
+then :
+  ac_cv_build_prog_cc_c11=$ac_arg
+fi
+rm -f core conftest.err conftest.$ac_build_objext conftest.beam
+  test "x$ac_cv_build_prog_cc_c11" != "xno" && break
+done
+rm -f conftest.$ac_ext
+CC_FOR_BUILD=$ac_save_CC
+fi
+
+if test "x$ac_cv_build_prog_cc_c11" = xno
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: unsupported" >&5
+printf "%s\n" "unsupported" >&6; }
+else $as_nop
+  if test "x$ac_cv_build_prog_cc_c11" = x
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: none needed" >&5
+printf "%s\n" "none needed" >&6; }
+else $as_nop
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_build_prog_cc_c11" >&5
+printf "%s\n" "$ac_cv_build_prog_cc_c11" >&6; }
+     CC_FOR_BUILD="$CC_FOR_BUILD $ac_cv_build_prog_cc_c11"
+fi
+  ac_cv_prog_cc_stdc=$ac_cv_build_prog_cc_c11
+  ac_prog_cc_stdc=c11
+fi
+fi
+if test x$ac_prog_cc_stdc = xno
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $CC_FOR_BUILD option to enable C99 features" >&5
+printf %s "checking for $CC_FOR_BUILD option to enable C99 features... " >&6; }
+if test ${ac_cv_build_prog_cc_c99+y}
+then :
+  printf %s "(cached) " >&6
+else $as_nop
+  ac_cv_build_prog_cc_c99=no
+ac_save_CC=$CC_FOR_BUILD
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+$ac_c_conftest_c99_program
+_ACEOF
+for ac_arg in '' -std=gnu99 -std=c99 -c99 -qlanglvl=extc1x -qlanglvl=extc99 -AC99 -D_STDC_C99=
+do
+  CC_FOR_BUILD="$ac_save_CC $ac_arg"
+  if ac_fn_c_try_compile "$LINENO"
+then :
+  ac_cv_build_prog_cc_c99=$ac_arg
+fi
+rm -f core conftest.err conftest.$ac_build_objext conftest.beam
+  test "x$ac_cv_build_prog_cc_c99" != "xno" && break
+done
+rm -f conftest.$ac_ext
+CC_FOR_BUILD=$ac_save_CC
+fi
+
+if test "x$ac_cv_build_prog_cc_c99" = xno
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: unsupported" >&5
+printf "%s\n" "unsupported" >&6; }
+else $as_nop
+  if test "x$ac_cv_build_prog_cc_c99" = x
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: none needed" >&5
+printf "%s\n" "none needed" >&6; }
+else $as_nop
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_build_prog_cc_c99" >&5
+printf "%s\n" "$ac_cv_build_prog_cc_c99" >&6; }
+     CC_FOR_BUILD="$CC_FOR_BUILD $ac_cv_build_prog_cc_c99"
+fi
+  ac_cv_prog_cc_stdc=$ac_cv_build_prog_cc_c99
+  ac_prog_cc_stdc=c99
+fi
+fi
+if test x$ac_prog_cc_stdc = xno
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $CC_FOR_BUILD option to enable C89 features" >&5
+printf %s "checking for $CC_FOR_BUILD option to enable C89 features... " >&6; }
+if test ${ac_cv_build_prog_cc_c89+y}
+then :
+  printf %s "(cached) " >&6
+else $as_nop
+  ac_cv_build_prog_cc_c89=no
+ac_save_CC=$CC_FOR_BUILD
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+$ac_c_conftest_c89_program
+_ACEOF
+for ac_arg in '' -qlanglvl=extc89 -qlanglvl=ansi -std -Ae "-Aa -D_HPUX_SOURCE" "-Xc -D__EXTENSIONS__"
+do
+  CC_FOR_BUILD="$ac_save_CC $ac_arg"
+  if ac_fn_c_try_compile "$LINENO"
+then :
+  ac_cv_build_prog_cc_c89=$ac_arg
+fi
+rm -f core conftest.err conftest.$ac_build_objext conftest.beam
+  test "x$ac_cv_build_prog_cc_c89" != "xno" && break
+done
+rm -f conftest.$ac_ext
+CC_FOR_BUILD=$ac_save_CC
+fi
+
+if test "x$ac_cv_build_prog_cc_c89" = xno
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: unsupported" >&5
+printf "%s\n" "unsupported" >&6; }
+else $as_nop
+  if test "x$ac_cv_build_prog_cc_c89" = x
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: none needed" >&5
+printf "%s\n" "none needed" >&6; }
+else $as_nop
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_build_prog_cc_c89" >&5
+printf "%s\n" "$ac_cv_build_prog_cc_c89" >&6; }
+     CC_FOR_BUILD="$CC_FOR_BUILD $ac_cv_build_prog_cc_c89"
+fi
+  ac_cv_prog_cc_stdc=$ac_cv_build_prog_cc_c89
+  ac_prog_cc_stdc=c89
+fi
+fi
+
+ac_ext=c
+ac_cpp='$CPP_FOR_BUILD $CPPFLAGS_FOR_BUILD'
+ac_compile='$CC_FOR_BUILD -c $CFLAGS_FOR_BUILD $CPPFLAGS_FOR_BUILD conftest.$ac_ext >&5'
+ac_link='$CC_FOR_BUILD -o conftest$ac_build_exeext $CFLAGS_FOR_BUILD $CPPFLAGS_FOR_BUILD $LDFLAGS_FOR_BUILD conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_build_c_compiler_gnu
+
+
+if test ${was_set_c_compiler_gnu}
+then :
+  ac_cv_c_compiler_gnu=$saved_c_compiler_gnu
+fi
+
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main (void)
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+ac_clean_files_save=$ac_clean_files
+ac_clean_files="$ac_clean_files a.out a.out.dSYM a.exe b.out"
+# Try to create an executable without -o first, disregard a.out.
+# It will help us diagnose broken compilers, and finding out an intuition
+# of exeext.
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether the C compiler works" >&5
+printf %s "checking whether the C compiler works... " >&6; }
+ac_link_default=`printf "%s\n" "$ac_link" | sed 's/ -o *conftest[^ ]*//'`
+
+# The possible output files:
+ac_files="a.out conftest.exe conftest a.exe a_out.exe b.out conftest.*"
+
+ac_rmfiles=
+for ac_file in $ac_files
+do
+  case $ac_file in
+    *.$ac_ext | *.xcoff | *.tds | *.d | *.pdb | *.xSYM | *.bb | *.bbg | *.map | *.inf | *.dSYM | *.o | *.obj ) ;;
+    * ) ac_rmfiles="$ac_rmfiles $ac_file";;
+  esac
+done
+rm -f $ac_rmfiles
+
+if { { ac_try="$ac_link_default"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
+printf "%s\n" "$ac_try_echo"; } >&5
+  (eval "$ac_link_default") 2>&5
+  ac_status=$?
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+then :
+  # Autoconf-2.13 could set the ac_cv_exeext variable to `no'.
+# So ignore a value of `no', otherwise this would lead to `EXEEXT = no'
+# in a Makefile.  We should not override ac_cv_exeext if it was cached,
+# so that the user can short-circuit this test for compilers unknown to
+# Autoconf.
+for ac_file in $ac_files ''
+do
+  test -f "$ac_file" || continue
+  case $ac_file in
+    *.$ac_ext | *.xcoff | *.tds | *.d | *.pdb | *.xSYM | *.bb | *.bbg | *.map | *.inf | *.dSYM | *.o | *.obj )
+	;;
+    [ab].out )
+	# We found the default executable, but exeext='' is most
+	# certainly right.
+	break;;
+    *.* )
+	if test ${ac_cv_build_exeext+y} && test "$ac_cv_build_exeext" != no;
+	then :; else
+	   ac_cv_build_exeext=`expr "$ac_file" : '[^.]*\(\..*\)'`
+	fi
+	# We set ac_cv_exeext here because the later test for it is not
+	# safe: cross compilers may not add the suffix if given an `-o'
+	# argument, so we may need to know it at that point already.
+	# Even if this section looks crufty: it has the advantage of
+	# actually working.
+	break;;
+    * )
+	break;;
+  esac
+done
+test "$ac_cv_build_exeext" = no && ac_cv_build_exeext=
+
+else $as_nop
+  ac_file=''
+fi
+if test -z "$ac_file"
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+printf "%s\n" "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+{ { printf "%s\n" "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+printf "%s\n" "$as_me: error: in \`$ac_pwd':" >&2;}
+as_fn_error 77 "C compiler cannot create executables
+See \`config.log' for more details" "$LINENO" 5; }
+else $as_nop
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for C compiler default output file name" >&5
+printf %s "checking for C compiler default output file name... " >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_file" >&5
+printf "%s\n" "$ac_file" >&6; }
+ac_build_exeext=$ac_cv_build_exeext
+
+rm -f -r a.out a.out.dSYM a.exe conftest$ac_cv_build_exeext b.out
+ac_clean_files=$ac_clean_files_save
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for suffix of executables" >&5
+printf %s "checking for suffix of executables... " >&6; }
+if { { ac_try="$ac_link"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
+printf "%s\n" "$ac_try_echo"; } >&5
+  (eval "$ac_link") 2>&5
+  ac_status=$?
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+then :
+  # If both `conftest.exe' and `conftest' are `present' (well, observable)
+# catch `conftest.exe'.  For instance with Cygwin, `ls conftest' will
+# work properly (i.e., refer to `conftest.exe'), while it won't with
+# `rm'.
+for ac_file in conftest.exe conftest conftest.*; do
+  test -f "$ac_file" || continue
+  case $ac_file in
+    *.$ac_ext | *.xcoff | *.tds | *.d | *.pdb | *.xSYM | *.bb | *.bbg | *.map | *.inf | *.dSYM | *.o | *.obj ) ;;
+    *.* ) ac_cv_build_exeext=`expr "$ac_file" : '[^.]*\(\..*\)'`
+	  break;;
+    * ) break;;
+  esac
+done
+else $as_nop
+  { { printf "%s\n" "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+printf "%s\n" "$as_me: error: in \`$ac_pwd':" >&2;}
+as_fn_error $? "cannot compute suffix of executables: cannot compile and link
+See \`config.log' for more details" "$LINENO" 5; }
+fi
+rm -f conftest conftest$ac_cv_build_exeext
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_build_exeext" >&5
+printf "%s\n" "$ac_cv_build_exeext" >&6; }
+
+rm -f conftest.$ac_ext
+EXEEXT=$ac_cv_build_exeext
+ac_build_exeext=$BUILD_EXEEXT
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <stdio.h>
+int
+main (void)
+{
+FILE *f = fopen ("conftest.out", "w");
+ return ferror (f) || fclose (f) != 0;
+
+  ;
+  return 0;
+}
+_ACEOF
+ac_clean_files="$ac_clean_files conftest.out"
+# Check that the compiler produces executables we can run.  If not, either
+# the compiler is broken, or we cross compile.
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether we are cross compiling" >&5
+printf %s "checking whether we are cross compiling... " >&6; }
+if test "$cross_compiling_build" != yes; then
+  { { ac_try="$ac_link"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
+printf "%s\n" "$ac_try_echo"; } >&5
+  (eval "$ac_link") 2>&5
+  ac_status=$?
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+  if { ac_try='./conftest$ac_cv_build_exeext'
+  { { case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
+printf "%s\n" "$ac_try_echo"; } >&5
+  (eval "$ac_try") 2>&5
+  ac_status=$?
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; }; then
+    cross_compiling_build=no
+  else
+    if test "$cross_compiling_build" = maybe; then
+	cross_compiling_build=yes
+    else
+	{ { printf "%s\n" "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+printf "%s\n" "$as_me: error: in \`$ac_pwd':" >&2;}
+as_fn_error 77 "cannot run C compiled programs.
+If you meant to cross compile, use \`--build'.
+See \`config.log' for more details" "$LINENO" 5; }
+    fi
+  fi
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $cross_compiling_build" >&5
+printf "%s\n" "$cross_compiling_build" >&6; }
+
+rm -f conftest.$ac_ext conftest$ac_cv_build_exeext conftest.out
+ac_clean_files=$ac_clean_files_save
+
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for suffix of object files" >&5
+printf %s "checking for suffix of object files... " >&6; }
+if test ${ac_cv_build_objext+y}
+then :
+  printf %s "(cached) " >&6
+else $as_nop
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main (void)
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.o conftest.obj
+if { { ac_try="$ac_compile"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
+printf "%s\n" "$ac_try_echo"; } >&5
+  (eval "$ac_compile") 2>&5
+  ac_status=$?
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+then :
+  for ac_file in conftest.o conftest.obj conftest.*; do
+  test -f "$ac_file" || continue;
+  case $ac_file in
+    *.$ac_ext | *.xcoff | *.tds | *.d | *.pdb | *.xSYM | *.bb | *.bbg | *.map | *.inf | *.dSYM ) ;;
+    *) ac_cv_build_objext=`expr "$ac_file" : '.*\.\(.*\)'`
+       break;;
+  esac
+done
+else $as_nop
+  printf "%s\n" "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+{ { printf "%s\n" "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+printf "%s\n" "$as_me: error: in \`$ac_pwd':" >&2;}
+as_fn_error $? "cannot compute suffix of object files: cannot compile
+See \`config.log' for more details" "$LINENO" 5; }
+fi
+rm -f conftest.$ac_cv_build_objext conftest.$ac_ext
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_build_objext" >&5
+printf "%s\n" "$ac_cv_build_objext" >&6; }
+OBJEXT=$ac_cv_build_objext
+ac_build_objext=$BUILD_OBJEXT
+
+ac_ext=c
+ac_cpp='$CPP_FOR_BUILD $CPPFLAGS_FOR_BUILD'
+ac_compile='$CC_FOR_BUILD -c $CFLAGS_FOR_BUILD $CPPFLAGS_FOR_BUILD conftest.$ac_ext >&5'
+ac_link='$CC_FOR_BUILD -o conftest$ac_build_exeext $CFLAGS_FOR_BUILD $CPPFLAGS_FOR_BUILD $LDFLAGS_FOR_BUILD conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_build_c_compiler_gnu
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking how to run the C preprocessor" >&5
+printf %s "checking how to run the C preprocessor... " >&6; }
+# On Suns, sometimes $CPP names a directory.
+if test -n "$CPP_FOR_BUILD" && test -d "$CPP_FOR_BUILD"; then
+  CPP_FOR_BUILD=
+fi
+if test -z "$CPP_FOR_BUILD"; then
+  if test ${ac_cv_build_prog_CPP+y}
+then :
+  printf %s "(cached) " >&6
+else $as_nop
+      # Double quotes because $CC needs to be expanded
+    for CPP_FOR_BUILD in "$CC_FOR_BUILD -E" "$CC_FOR_BUILD -E -traditional-cpp" cpp /lib/cpp
+    do
+      ac_preproc_ok=false
+for ac_c_preproc_warn_flag in '' yes
+do
+  # Use a header file that comes with gcc, so configuring glibc
+  # with a fresh cross-compiler works.
+  # On the NeXT, cc -E runs the code through the compiler's parser,
+  # not just through cpp. "Syntax error" is here to catch this case.
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <limits.h>
+		     Syntax error
+_ACEOF
+if ac_fn_c_try_cpp "$LINENO"
+then :
+
+else $as_nop
+  # Broken: fails on valid input.
+continue
+fi
+rm -f conftest.err conftest.i conftest.$ac_ext
+
+  # OK, works on sane cases.  Now check whether nonexistent headers
+  # can be detected and how.
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <ac_nonexistent.h>
+_ACEOF
+if ac_fn_c_try_cpp "$LINENO"
+then :
+  # Broken: success on invalid input.
+continue
+else $as_nop
+  # Passes both tests.
+ac_preproc_ok=:
+break
+fi
+rm -f conftest.err conftest.i conftest.$ac_ext
+
+done
+# Because of `break', _AC_PREPROC_IFELSE's cleaning code was skipped.
+rm -f conftest.i conftest.err conftest.$ac_ext
+if $ac_preproc_ok
+then :
+  break
+fi
+
+    done
+    ac_cv_build_prog_CPP=$CPP_FOR_BUILD
+
+fi
+  CPP_FOR_BUILD=$ac_cv_build_prog_CPP
+else
+  ac_cv_build_prog_CPP=$CPP_FOR_BUILD
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $CPP_FOR_BUILD" >&5
+printf "%s\n" "$CPP_FOR_BUILD" >&6; }
+ac_preproc_ok=false
+for ac_c_preproc_warn_flag in '' yes
+do
+  # Use a header file that comes with gcc, so configuring glibc
+  # with a fresh cross-compiler works.
+  # On the NeXT, cc -E runs the code through the compiler's parser,
+  # not just through cpp. "Syntax error" is here to catch this case.
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <limits.h>
+		     Syntax error
+_ACEOF
+if ac_fn_c_try_cpp "$LINENO"
+then :
+
+else $as_nop
+  # Broken: fails on valid input.
+continue
+fi
+rm -f conftest.err conftest.i conftest.$ac_ext
+
+  # OK, works on sane cases.  Now check whether nonexistent headers
+  # can be detected and how.
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <ac_nonexistent.h>
+_ACEOF
+if ac_fn_c_try_cpp "$LINENO"
+then :
+  # Broken: success on invalid input.
+continue
+else $as_nop
+  # Passes both tests.
+ac_preproc_ok=:
+break
+fi
+rm -f conftest.err conftest.i conftest.$ac_ext
+
+done
+# Because of `break', _AC_PREPROC_IFELSE's cleaning code was skipped.
+rm -f conftest.i conftest.err conftest.$ac_ext
+if $ac_preproc_ok
+then :
+
+else $as_nop
+  { { printf "%s\n" "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+printf "%s\n" "$as_me: error: in \`$ac_pwd':" >&2;}
+as_fn_error $? "C preprocessor \"$CPP_FOR_BUILD\" fails sanity check
+See \`config.log' for more details" "$LINENO" 5; }
+fi
+
+ac_ext=c
+ac_cpp='$CPP_FOR_BUILD $CPPFLAGS_FOR_BUILD'
+ac_compile='$CC_FOR_BUILD -c $CFLAGS_FOR_BUILD $CPPFLAGS_FOR_BUILD conftest.$ac_ext >&5'
+ac_link='$CC_FOR_BUILD -o conftest$ac_build_exeext $CFLAGS_FOR_BUILD $CPPFLAGS_FOR_BUILD $LDFLAGS_FOR_BUILD conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_build_c_compiler_gnu
+
+
+
+ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+
+
+fi
+
+# Checks for programs
+
+## Check for the C compiler: done by libtool
+## AC_PROG_CC
+
+## Check for C99 support: done by libtool
+## AC_PROG_CC_C99
+
+## Determine which flags to use for the C compiler
+
+case $ocaml_cc_vendor in #(
+  xlc-*) :
+    outputobj='-o '
+    warn_error_flag=''
+    cc_warnings='-qflag=i:i' ;; #(
+  # all warnings enabled
+  sunc-*) :
+    outputobj='-o '; cc_warnings="" ;; #(
+  msvc-*) :
+    outputobj='-Fo'
+    warn_error_flag='-WX'
+    cc_warnings='' ;; #(
+  *) :
+    outputobj='-o '
+  warn_error_flag='-Werror'
+  cc_warnings="-Wall -Wint-conversion -Wstrict-prototypes \
+-Wold-style-definition -Wundef" ;;
+esac
+
+# Use -Wold-style-declaration if supported
+as_CACHEVAR=`printf "%s\n" "ax_cv_check_cflags_$warn_error_flag_-Wold-style-declaration" | $as_tr_sh`
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether C compiler accepts -Wold-style-declaration" >&5
+printf %s "checking whether C compiler accepts -Wold-style-declaration... " >&6; }
+if eval test \${$as_CACHEVAR+y}
+then :
+  printf %s "(cached) " >&6
+else $as_nop
+
+  ax_check_save_flags=$CFLAGS
+  CFLAGS="$CFLAGS $warn_error_flag -Wold-style-declaration"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main (void)
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"
+then :
+  eval "$as_CACHEVAR=yes"
+else $as_nop
+  eval "$as_CACHEVAR=no"
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
+  CFLAGS=$ax_check_save_flags
+fi
+eval ac_res=\$$as_CACHEVAR
+	       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+printf "%s\n" "$ac_res" >&6; }
+if eval test \"x\$"$as_CACHEVAR"\" = x"yes"
+then :
+  cc_warnings="$cc_warnings -Wold-style-declaration"
+else $as_nop
+  :
+fi
+
+
+case $enable_warn_error,false in #(
+  yes,*|,true) :
+    cc_warnings="$cc_warnings $warn_error_flag" ;; #(
+  *) :
+     ;;
+esac
 
 # We select high optimization levels, provided we can turn off:
 # - strict type-based aliasing analysis (too risky for the OCaml runtime)
@@ -14028,7 +15258,7 @@ fi
 esac
 
 # Enable SSE2 on x86 mingw to avoid using 80-bit registers.
-case $host in #(
+case $target in #(
   i686-*-mingw32*) :
     internal_cflags="$internal_cflags -mfpmath=sse -msse2" ;; #(
   *) :
@@ -14038,7 +15268,7 @@ esac
 # Use 64-bit file offset if possible
 # See also AC_SYS_LARGEFILE
 # Problem: flags are added to CC rather than CPPFLAGS
-case $host in #(
+case $target in #(
   *-*-mingw32*|*-pc-windows) :
      ;; #(
   *) :
@@ -14056,7 +15286,7 @@ esac
 if test x"$enable_shared" = "xno"
 then :
   supports_shared_libraries=false
-  case $host in #(
+  case $target in #(
   *-pc-windows|*-w64-mingw32*) :
     as_fn_error $? "Cannot build native Win32 with --disable-shared" "$LINENO" 5 ;; #(
   *) :
@@ -14068,7 +15298,7 @@ fi
 
 # Define flexlink chain and flags correctly for the different Windows ports
 flexlink_flags=''
-case $host in #(
+case $target in #(
   i686-*-cygwin) :
     flexdll_chain='cygwin'
     flexlink_flags='-merge-manifest -stack 16777216' ;; #(
@@ -14395,7 +15625,7 @@ fi
 
 fi
 
-case $have_flexdll_h,$supports_shared_libraries,$host in #(
+case $have_flexdll_h,$supports_shared_libraries,$target in #(
   no,true,*-*-cygwin*) :
     supports_shared_libraries=false
    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: flexdll.h not found: shared library support disabled." >&5
@@ -14406,7 +15636,7 @@ printf "%s\n" "$as_me: WARNING: flexdll.h not found: shared library support disa
      ;;
 esac
 
-case $flexdll_source_dir,$supports_shared_libraries,$flexlink,$host in #(
+case $flexdll_source_dir,$supports_shared_libraries,$flexlink,$target in #(
   ,true,,*-*-cygwin*) :
     supports_shared_libraries=false
     { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: flexlink not found: shared library support disabled." >&5
@@ -14419,7 +15649,7 @@ esac
 
 mkexe_cmd_exp="$CC"
 
-case $ocaml_cc_vendor,$host in #(
+case $ocaml_cc_vendor,$target in #(
   *,x86_64-*-darwin*) :
     oc_ldflags='-Wl,-no_compact_unwind';
     printf "%s\n" "#define HAS_ARCH_CODE32 1" >>confdefs.h
@@ -14442,7 +15672,7 @@ else $as_nop
 fi
     ostype="Cygwin" ;; #(
   *,*-*-mingw32*) :
-    case $host in #(
+    case $target in #(
   i686-*-*) :
     oc_dll_ldflags="-static-libgcc" ;; #(
   *) :
@@ -14477,6 +15707,8 @@ esac
  ;; #(
   gcc-*,powerpc-*-linux*) :
     oc_ldflags="-mbss-plt" ;; #(
+  *,*-*-none|*,*-*-elf*) :
+    ostype="None" ;; #(
   *) :
      ;;
 esac
@@ -14655,7 +15887,7 @@ fi
 # Checks for header files
 
 # Don't check for unistd.h on Windows
-case $host in #(
+case $target in #(
   *-*-mingw32*|*-pc-windows) :
      ;; #(
   *) :
@@ -15365,7 +16597,7 @@ fi
 # Full support for thread local storage
 # macOS and MinGW-w64 have problems with thread local storage accessed from DLLs
 
-case $host in #(
+case $target in #(
   *-apple-darwin*|*-mingw32*) :
      ;; #(
   *) :
@@ -15386,7 +16618,7 @@ natdynlinkopts=""
 if test x"$enable_shared" != "xno"
 then :
   mkdll=''
-  case $host in #(
+  case $target in #(
   x86_64-apple-darwin*) :
     mkdll_flags=\
 '-shared -undefined dynamic_lookup -Wl,-no_compact_unwind -Wl,-w'
@@ -15417,7 +16649,7 @@ esac ;; #(
   *-*-linux*|*-*-freebsd[3-9]*|*-*-freebsd[1-9][0-9]*\
     |*-*-openbsd*|*-*-netbsd*|*-*-dragonfly*|*-*-gnu*|*-*-haiku*) :
     sharedlib_cflags="-fPIC"
-       case $ocaml_cc_vendor,$host in #(
+       case $ocaml_cc_vendor,$target in #(
   gcc-*,powerpc-*-linux*) :
     mkdll_flags='-shared -mbss-plt' ;; #(
   *,i[3456]86-*) :
@@ -15427,7 +16659,7 @@ esac ;; #(
   *) :
     mkdll_flags='-shared' ;;
 esac
-       case $host in #(
+       case $target in #(
   *-*-openbsd7.[3-9]|*-*-openbsd[89].*) :
     mkdll_flags="${mkdll_flags} -Wl,--no-execute-only" ;; #(
   *) :
@@ -15457,7 +16689,7 @@ fi
 # Make sure code sections in OCaml-generated executables are readable
 # (required for marshaling of function closures)
 
-case $host in #(
+case $target in #(
   *-*-openbsd7.[3-9]|*-*-openbsd[89].*) :
     oc_ldflags="$oc_ldflags -Wl,--no-execute-only"
      natdynlinkopts="$natdynlinkopts -Wl,--no-execute-only" ;; #(
@@ -15467,7 +16699,7 @@ esac
 
 # Disable control flow integrity
 
-case $host in #(
+case $target in #(
   *-*-openbsd7.[4-9]|*-*-openbsd[89].*) :
     oc_ldflags="$oc_ldflags -Wl,-z,nobtcfi"
      natdynlinkopts="$natdynlinkopts -Wl,-z,nobtcfi" ;; #(
@@ -15482,7 +16714,7 @@ natdynlink=false
 
 if test x"$supports_shared_libraries" = 'xtrue'
 then :
-  case "$host" in #(
+  case "$target" in #(
   *-*-cygwin*) :
     natdynlink=true ;; #(
   *-*-mingw32*) :
@@ -15560,7 +16792,7 @@ case $enable_native_toplevel,$natdynlink in #(
 esac
 
 # Try to work around the Skylake/Kaby Lake processor bug.
-case "$ocaml_cc_vendor,$host" in #(
+case "$ocaml_cc_vendor,$target" in #(
   *gcc*,x86_64-*|*gcc*,i686-*) :
 
   { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether the C compiler supports -fno-tree-vrp" >&5
@@ -15648,7 +16880,7 @@ system=unknown
 # preserving $arch = 'none' <=> $system = 'unknown'
 has_native_backend=no
 native_ldflags=""
-case $host in #(
+case $target in #(
   i[3456]86-*-linux*) :
     arch=i386; system=linux ;; #(
   i[3456]86-*-freebsd*) :
@@ -15748,7 +16980,19 @@ fi ;; #(
   x86_64-*-cygwin*) :
     has_native_backend=yes; arch=amd64; system=cygwin ;; #(
   riscv64-*-linux*) :
-    has_native_backend=yes; arch=riscv; model=riscv64; system=linux
+    has_native_backend=yes; arch=riscv; model=riscv64; system=linux ;; #(
+  aarch64-*-none|arm64-*-none|aarch64-*-elf*|arm64-*-elf*) :
+    has_native_backend=yes; arch=arm64; system=none ;; #(
+  powerpc64le*-*-none|powerpc64le*-*-elf*) :
+    has_native_backend=yes; arch=power; model=ppc64le; system=none ;; #(
+  powerpc64*-*-none|powerpc64*-*-elf*) :
+    has_native_backend=yes; arch=power; model=ppc64; system=none ;; #(
+  riscv64-*-none|riscv64-*-elf*) :
+    has_native_backend=yes; arch=riscv; model=riscv64; system=none ;; #(
+  s390x*-*-none|s390x*-*-elf*) :
+    has_native_backend=yes; arch=s390x; model=z10; system=none ;; #(
+  x86_64-*-none|x86_64-*-elf*) :
+    has_native_backend=yes; arch=amd64; system=none
  ;; #(
   *) :
      ;;
@@ -15813,10 +17057,10 @@ fi
 
 printf "%s\n" "#define OCAML_OS_TYPE \"$ostype\"" >>confdefs.h
 
+target_os_type="$ostype"
 
-if test -n "$ac_tool_prefix"; then
-  # Extract the first word of "${ac_tool_prefix}ld", so it can be a program name with args.
-set dummy ${ac_tool_prefix}ld; ac_word=$2
+# Extract the first word of "$target_alias-ld", so it can be a program name with args.
+set dummy $target_alias-ld; ac_word=$2
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
 printf %s "checking for $ac_word... " >&6; }
 if test ${ac_cv_prog_DIRECT_LD+y}
@@ -15837,7 +17081,7 @@ do
   esac
     for ac_exec_ext in '' $ac_executable_extensions; do
   if as_fn_executable_p "$as_dir$ac_word$ac_exec_ext"; then
-    ac_cv_prog_DIRECT_LD="${ac_tool_prefix}ld"
+    ac_cv_prog_DIRECT_LD="$target_alias-ld"
     printf "%s\n" "$as_me:${as_lineno-$LINENO}: found $as_dir$ac_word$ac_exec_ext" >&5
     break 2
   fi
@@ -15857,10 +17101,10 @@ printf "%s\n" "no" >&6; }
 fi
 
 
-fi
 if test -z "$ac_cv_prog_DIRECT_LD"; then
-  ac_ct_DIRECT_LD=$DIRECT_LD
-  # Extract the first word of "ld", so it can be a program name with args.
+  if test "$build" = "$target"; then
+    ac_ct_DIRECT_LD=$DIRECT_LD
+    # Extract the first word of "ld", so it can be a program name with args.
 set dummy ld; ac_word=$2
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
 printf %s "checking for $ac_word... " >&6; }
@@ -15901,16 +17145,9 @@ else
 printf "%s\n" "no" >&6; }
 fi
 
-  if test "x$ac_ct_DIRECT_LD" = x; then
-    DIRECT_LD=""
-  else
-    case $cross_compiling:$ac_tool_warned in
-yes:)
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
-printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
-ac_tool_warned=yes ;;
-esac
     DIRECT_LD=$ac_ct_DIRECT_LD
+  else
+    DIRECT_LD=""
   fi
 else
   DIRECT_LD="$ac_cv_prog_DIRECT_LD"
@@ -15918,7 +17155,7 @@ fi
 
 if test -z "$PARTIALLD"
 then :
-  case "$host,$ocaml_cc_vendor" in #(
+  case "$target,$ocaml_cc_vendor" in #(
   x86_64-*-darwin*,gcc-*) :
     PACKLD_FLAGS=' -arch x86_64' ;; #(
   powerpc64le*-*-linux*,gcc-*) :
@@ -15965,7 +17202,7 @@ case $arch in #(
     # ocamlopt generates PIC code or doesn't generate code at all
      ;; #(
   *) :
-    case $host in #(
+    case $target in #(
   # expected to match "*-linux-musl" as well as "*-linux-musleabi*"
     *-linux-musl*) :
     # Alpine and other musl-based Linux distributions
@@ -16168,7 +17405,7 @@ then :
 printf %s "checking whether round works... " >&6; }
 
   old_cross_compiling="$cross_compiling"
-  if test "x$host_runnable" = 'xtrue'
+  if test "x$target_runnable" = 'xtrue'
 then :
   cross_compiling='no'
 fi
@@ -16236,7 +17473,7 @@ fi
 printf %s "checking whether fma works... " >&6; }
 
   old_cross_compiling="$cross_compiling"
-  if test "x$host_runnable" = 'xtrue'
+  if test "x$target_runnable" = 'xtrue'
 then :
   cross_compiling='no'
 fi
@@ -16507,7 +17744,7 @@ fi
 ## On MacOS clock_gettime's CLOCK_MONOTONIC flag is not actually monotonic.
 ## mach_timebase_info and mach_absolute_time are used instead.
 
-case $host in #(
+case $target in #(
   *-*-windows) :
     has_monotonic_clock=true ;; #(
   *-apple-darwin*) :
@@ -16567,7 +17804,7 @@ esac
 if test "x$enable_instrumented_runtime" != "xno"
 then :
 
-    case $host in #(
+    case $target in #(
   sparc-sun-solaris*) :
     instrumented_runtime=false ;; #(
   *-*-windows) :
@@ -16952,7 +18189,7 @@ fi
 
 sockets=true
 
-case $host in #(
+case $target in #(
   *-*-mingw32*) :
     cclibs="$cclibs -lws2_32"
     { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for library containing socket" >&5
@@ -17300,7 +18537,7 @@ fi
 
 ## socklen_t
 
-case $host in #(
+case $target in #(
   *-*-mingw32*|*-pc-windows) :
     ac_fn_c_check_type "$LINENO" "socklen_t" "ac_cv_type_socklen_t" "#include <ws2tcpip.h>
 "
@@ -17331,7 +18568,7 @@ fi
 
 ## Unix domain sockets support on Windows
 
-case $host in #(
+case $target in #(
   *-*-mingw32*|*-pc-windows) :
            for ac_header in afunix.h
 do :
@@ -17353,7 +18590,7 @@ esac
 
 ipv6=true
 
-case $host in #(
+case $target in #(
   *-*-mingw32*|*-pc-windows) :
     ac_fn_c_check_type "$LINENO" "struct sockaddr_in6" "ac_cv_type_struct_sockaddr_in6" "#include <ws2tcpip.h>
 "
@@ -17473,7 +18710,7 @@ fi
 ## Note: this was defined in config/s-nt.h but the autoconf macros do not
 # seem to detect it properly on Windows so we hardcode the definition
 # of HAS_UTIME on Windows but this will probably need to be clarified
-case $host in #(
+case $target in #(
   *-*-mingw32*|*-pc-windows) :
     printf "%s\n" "#define HAS_UTIME 1" >>confdefs.h
  ;; #(
@@ -17691,7 +18928,7 @@ fi
 ## gethostname
 # Note: detection fails on Windows so hardcoding the result
 # (should be debugged later)
-case $host in #(
+case $target in #(
   *-*-mingw32*|*-pc-windows) :
     printf "%s\n" "#define HAS_GETHOSTNAME 1" >>confdefs.h
  ;; #(
@@ -17747,7 +18984,7 @@ fi
 
 ## setsid
 
-case $host in #(
+case $target in #(
   *-cygwin|*-*-mingw32*|*-pc-windows) :
      ;; #(
   *) :
@@ -17788,7 +19025,7 @@ fi
 ## newlocale() and <locale.h>
 # Note: the detection fails on msvc so we hardcode the result
 # (should be debugged later)
-case $host in #(
+case $target in #(
   *-pc-windows) :
     printf "%s\n" "#define HAS_LOCALE_H 1" >>confdefs.h
  ;; #(
@@ -17843,7 +19080,7 @@ fi
 ## strtod_l
 # Note: not detected on MSVC so hardcoding the result
 # (should be debugged later)
-case $host in #(
+case $target in #(
   *-pc-windows) :
     printf "%s\n" "#define HAS_STRTOD_L 1" >>confdefs.h
  ;; #(
@@ -17860,7 +19097,7 @@ esac
 ## shared library support
 if $supports_shared_libraries
 then :
-  case $host in #(
+  case $target in #(
   *-*-mingw32*|*-pc-windows|*-*-cygwin*) :
     DLLIBS="" ;; #(
   *) :
@@ -17960,7 +19197,7 @@ fi
 
 
 ## -fdebug-prefix-map support by the C compiler
-case $ocaml_cc_vendor,$host in #(
+case $ocaml_cc_vendor,$target in #(
   *,*-*-mingw32*) :
     cc_has_debug_prefix_map=false ;; #(
   *,*-pc-windows) :
@@ -18571,9 +19808,8 @@ fi
 fi
 
 
-if test -n "$ac_tool_prefix"; then
-  # Extract the first word of "${ac_tool_prefix}pkg-config", so it can be a program name with args.
-set dummy ${ac_tool_prefix}pkg-config; ac_word=$2
+# Extract the first word of "$target_alias-pkg-config", so it can be a program name with args.
+set dummy $target_alias-pkg-config; ac_word=$2
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
 printf %s "checking for $ac_word... " >&6; }
 if test ${ac_cv_path_PKG_CONFIG+y}
@@ -18617,10 +19853,10 @@ printf "%s\n" "no" >&6; }
 fi
 
 
-fi
 if test -z "$ac_cv_path_PKG_CONFIG"; then
-  ac_pt_PKG_CONFIG=$PKG_CONFIG
-  # Extract the first word of "pkg-config", so it can be a program name with args.
+  if test "$build" = "$target"; then
+    ac_pt_PKG_CONFIG=$PKG_CONFIG
+    # Extract the first word of "pkg-config", so it can be a program name with args.
 set dummy pkg-config; ac_word=$2
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
 printf %s "checking for $ac_word... " >&6; }
@@ -18652,6 +19888,7 @@ done
   done
 IFS=$as_save_IFS
 
+  test -z "$ac_cv_path_ac_pt_PKG_CONFIG" && ac_cv_path_ac_pt_PKG_CONFIG="false"
   ;;
 esac
 fi
@@ -18664,16 +19901,9 @@ else
 printf "%s\n" "no" >&6; }
 fi
 
-  if test "x$ac_pt_PKG_CONFIG" = x; then
-    PKG_CONFIG="false"
-  else
-    case $cross_compiling:$ac_tool_warned in
-yes:)
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
-printf "%s\n" "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
-ac_tool_warned=yes ;;
-esac
     PKG_CONFIG=$ac_pt_PKG_CONFIG
+  else
+    PKG_CONFIG="false"
   fi
 else
   PKG_CONFIG="$ac_cv_path_PKG_CONFIG"
@@ -18760,9 +19990,9 @@ fi
 # library available, but not have the DLL in PATH. This then causes the build to
 # fail as soon as ocamlrun is first executed. This check avoids automatically
 # enabling zstd when the resulting executable doesn't actually work.
-case $host in #(
+case $target in #(
   *-w64-mingw32*|*-pc-windows) :
-    check_zstd_runs=$host_runnable ;; #(
+    check_zstd_runs=$target_runnable ;; #(
   *) :
     check_zstd_runs=false ;;
 esac
@@ -18896,7 +20126,7 @@ esac
 
 ## Determine how to link with the POSIX threads library
 
-case $host in #(
+case $target in #(
   *-*-mingw32*) :
     PTHREAD_LIBS="-l:libpthread.a -lgcc_eh" ;; #(
   *-pc-windows) :
@@ -19764,7 +20994,7 @@ as_has_debug_prefix_map=false
 asm_cfi_supported=false
 if $native_compiler
 then :
-  case $host in #(
+  case $target in #(
   *-*-mingw32*|*-pc-windows) :
      ;; #(
   *) :
@@ -19937,7 +21167,7 @@ fi
 
 if test x"$enable_frame_pointers" = "xyes"
 then :
-  case "$host,$ocaml_cc_vendor" in #(
+  case "$target,$ocaml_cc_vendor" in #(
   x86_64-*-linux*,gcc-*|x86_64-*-linux*,clang-*) :
     common_cflags="$common_cflags -g  -fno-omit-frame-pointer"
       frame_pointers=true
@@ -20351,7 +21581,7 @@ oc_cppflags="$common_cppflags $internal_cppflags"
 ocamlc_cflags="$ocamlc_cflags $common_cflags $sharedlib_cflags $CFLAGS"
 ocamlc_cppflags="$common_cppflags $CPPFLAGS"
 
-case $host in #(
+case $target in #(
   *-*-mingw32*) :
     cclibs="$cclibs -lole32 -luuid -lversion" ;; #(
   *-pc-windows) :
@@ -20379,7 +21609,7 @@ then :
   mandir='${prefix}/man'
 fi
 
-case $host in #(
+case $target in #(
   *-*-mingw32*|*-pc-windows) :
     case $WINDOWS_UNICODE_MODE in #(
   ansi) :
@@ -20424,7 +21654,7 @@ fi
 # Define a few macros that were defined in config/m-nt.h
 # but whose value is not guessed properly by configure
 # (all this should be understood and fixed)
-case $host in #(
+case $target in #(
   *-*-mingw32*) :
     printf "%s\n" "#define HAS_BROKEN_PRINTF 1" >>confdefs.h
 
diff --git a/configure.ac b/configure.ac
index 0c9d63859a96..2a1cc9995fa8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -140,6 +140,7 @@ AC_SUBST([arch_specific_SOURCES])
 AC_SUBST([arch64])
 AC_SUBST([model])
 AC_SUBST([system])
+AC_SUBST([target_os_type])
 AC_SUBST([native_cflags])
 AC_SUBST([native_cppflags])
 AC_SUBST([systhread_support])
@@ -286,7 +287,32 @@ AC_CONFIG_COMMANDS_PRE(OCAML_QUOTED_STRING_ID)
 
 AC_CANONICAL_BUILD
 AC_CANONICAL_HOST
+# Allow "ocaml" as target OS for freestanding compiler by temporarily rewriting
+# the target OS to "none" to generate the canonical target
+real_target_alias="$target_alias"
+AS_CASE([$target_alias],
+  [*-*-*-ocaml],
+    [ac_save_IFS=$IFS
+    IFS='-'
+    set x $target_alias
+    target_alias="$2-$3-none"
+    IFS=$ac_save_IFS],
+  [*-*-ocaml],
+    [ac_save_IFS=$IFS
+    IFS='-'
+    set x $target_alias
+    target_alias="$2-none"
+    IFS=$ac_save_IFS])
 AC_CANONICAL_TARGET
+target_alias="$real_target_alias"
+
+# Override cross_compiling and ac_tool_prefix variables since the C toolchain is
+# used to generate target code when building a cross compiler
+AS_IF([test x"$build" = x"$target"],
+  [cross_compiling=no],
+  [cross_compiling=yes])
+AS_IF([test -n "$target_alias"],
+  [ac_tool_prefix=$target_alias-])
 
 # Ensure that AC_CONFIG_LINKS will either create symlinks which are compatible
 # with native Windows (i.e. NTFS symlinks, not WSL or Cygwin-emulated ones) or
@@ -300,7 +326,7 @@ AS_CASE([$host],
 
 # Systems that are known not to work, even in bytecode only.
 
-AS_CASE([$host],
+AS_CASE([$target],
   [*-pc-windows],
     [AC_MSG_ERROR([the MSVC compiler is not supported currently], 69)],
   [i386-*-solaris*],
@@ -310,7 +336,7 @@ If your host is 64 bits, you can try with './configure CC="gcc -m64"' \
 
 # MSVC special case
 
-AS_CASE([$host],
+AS_CASE([$target],
   [*-pc-windows],
     [CC=cl
     ccomptype=msvc
@@ -589,7 +615,17 @@ AS_IF([test x"$enable_ocamldoc" = "xno"],
 # Initialization of libtool
 # Allow the MSVC linker to be found even if ld isn't installed.
 # User-specified LD still takes precedence.
-AC_CHECK_TOOLS([LD],[ld link])
+AC_CHECK_TARGET_TOOLS([LD],[ld link])
+# libtool will detect a build-to-host C toolchain but when building an OCaml
+# cross compiler we need the C toolchain to build the target runtime so we
+# temporarily define host* values as macros for target* values so that the
+# proper toolchain is configured. Note that host=target unless we are building a
+# cross compiler so this is transparent for the usual use case.
+pushdef([host], target)dnl
+pushdef([host_alias], target_alias)dnl
+pushdef([host_cpu], target_cpu)dnl
+pushdef([host_vendor], target_vendor)dnl
+pushdef([host_os], target_os)dnl
 # libtool expects host_os=mingw for native Windows
 # Also, it has been observed that, on some platforms (e.g. msvc) LT_INIT
 # alters the CFLAGS variable, so we save its value before calling the macro
@@ -600,6 +636,11 @@ saved_CFLAGS="$CFLAGS"
 LT_INIT
 CFLAGS="$saved_CFLAGS"
 host_os=$old_host_os
+popdef([host_os])dnl
+popdef([host_vendor])dnl
+popdef([host_cpu])dnl
+popdef([host_alias])dnl
+popdef([host])dnl
 
 AS_CASE([$host],
   [sparc-sun-solaris*],
@@ -624,7 +665,7 @@ AS_CASE([$enable_dependency_generation],
       [compute_deps=true])],
     [compute_deps=false])])
 
-AS_CASE([$host],
+AS_CASE([$target],
   # In config/Makefile.mingw*, we had:
   # TARGET=i686-w64-mingw32 and x86_64-w64-mingw32
   # TOOLPREF=$(TARGET)-
@@ -636,7 +677,7 @@ AS_CASE([$host],
       mkexe_via_cc_extra_cmd=' && $(call MERGEMANIFESTEXE,$(1))'
       libext=lib
       AR=""
-      AS_IF([test "$host_cpu" = "x86_64" ],
+      AS_IF([test "$target_cpu" = "x86_64" ],
         [machine="-machine:AMD64 "],
         [machine=""])
       mklib="link -lib -nologo $machine /out:\$(1) \$(2)"
@@ -650,7 +691,7 @@ OCAML_CC_VENDOR
 
 ## In cross-compilation mode, can we run executables produced?
 # At the moment, it's required, but the fact is used in C99 function detection
-OCAML_HOST_IS_EXECUTABLE
+OCAML_TARGET_IS_EXECUTABLE
 
 # Determine how to call the C preprocessor directly.
 # Most of the time, calling the C preprocessor through the C compiler is
@@ -697,21 +738,24 @@ AS_CASE([lt_cv_ar_at_file],
   [no], [ar_supports_response_files=false],
   [ar_supports_response_files=true])
 
-# Libraries to build depending on the host
+# Libraries to build depending on the target
 
 AS_CASE([$host],
   [*-*-mingw32*|*-pc-windows],
-    [unix_or_win32="win32"
-    ln='cp -pf'
+    [ln='cp -pf'
+    ocamlsrcdir="$(LC_ALL=C.UTF-8 cygpath -w -- "$ocamlsrcdir")"],
+  [ln='ln -sf'])
+
+AS_CASE([$target],
+  [*-*-mingw32*|*-pc-windows],
+    [unix_or_win32="win32" # or should it be tested against host?
     ocamltest_libunix="Some false"
-    ocamlsrcdir="$(LC_ALL=C.UTF-8 cygpath -w -- "$ocamlsrcdir")"
     ocamlyacc_wstr_module="yacc/wstr"],
   [unix_or_win32="unix"
-  ln='ln -sf'
   ocamltest_libunix="Some true"
   ocamlyacc_wstr_module=""])
 
-AS_CASE([$host],
+AS_CASE([$target],
   [*-*-cygwin*|*-*-mingw32*|*-pc-windows],
     [exeext=".exe"],
   [exeext=''])
@@ -746,7 +790,7 @@ AC_SYS_INTERPRETER
 shebangscripts=false
 launch_method='exe'
 AS_IF([test "x$interpval" = "xyes"],
-  [AS_CASE([$host],
+  [AS_CASE([$target],
     [*-cygwin],
       [# Cygwin supports shebangs, which we use for the compiler itself, but
       # partially for legacy, and partially so that executables can be easily
@@ -785,7 +829,23 @@ dnl nefarious single quotes which may appear in any of the strings.
 AS_IF(
   [test x"$host" = x"$target"],
     [cross_compiler=false],
-    [cross_compiler=true])
+    [cross_compiler=true
+    # We require a non-cross-compiler of the same version
+    AC_MSG_CHECKING([the version of the installed OCaml compiler])
+    already_installed_version=`ocamlc -vnum`
+    AS_IF([test x"AC_PACKAGE_VERSION" = x"$already_installed_version"],
+          [AC_MSG_RESULT([compatible (AC_PACKAGE_VERSION)])],
+          [AC_MSG_ERROR(m4_normalize([incompatible (AC_PACKAGE_VERSION vs
+             $already_installed_version)]))])])
+
+AS_IF(
+  [test x"$build" = x"$target" -o x"$target_runnable" = xtrue],
+    [CC_FOR_BUILD='$(CC)'
+    CFLAGS_FOR_BUILD='$(CFLAGS)'
+    CPPFLAGS_FOR_BUILD='$(CPPFLAGS)'
+    LDFLAGS_FOR_BUILD='$(LDFLAGS)'],
+    [AC_MSG_NOTICE([detecting the C toolchain for build])
+    AX_PROG_CC_FOR_BUILD])
 
 # Checks for programs
 
@@ -870,14 +930,14 @@ AS_CASE([$ocaml_cc_vendor],
   [common_cflags="-O"])
 
 # Enable SSE2 on x86 mingw to avoid using 80-bit registers.
-AS_CASE([$host],
+AS_CASE([$target],
   [i686-*-mingw32*],
     [internal_cflags="$internal_cflags -mfpmath=sse -msse2"])
 
 # Use 64-bit file offset if possible
 # See also AC_SYS_LARGEFILE
 # Problem: flags are added to CC rather than CPPFLAGS
-AS_CASE([$host],
+AS_CASE([$target],
   [*-*-mingw32*|*-pc-windows], [],
   [common_cppflags="$common_cppflags -D_FILE_OFFSET_BITS=64"])
 
@@ -891,14 +951,14 @@ AS_CASE([$host],
 
 AS_IF([test x"$enable_shared" = "xno"],
   [supports_shared_libraries=false
-  AS_CASE([$host],
+  AS_CASE([$target],
     [*-pc-windows|*-w64-mingw32*],
     [AC_MSG_ERROR([Cannot build native Win32 with --disable-shared])])],
   [supports_shared_libraries=true])
 
 # Define flexlink chain and flags correctly for the different Windows ports
 flexlink_flags=''
-AS_CASE([$host],
+AS_CASE([$target],
   [i686-*-cygwin],
     [flexdll_chain='cygwin'
     flexlink_flags='-merge-manifest -stack 16777216'],
@@ -987,14 +1047,14 @@ AS_IF([test x"$supports_shared_libraries" != 'xfalse'], [
   ])
 ])
 
-AS_CASE([$have_flexdll_h,$supports_shared_libraries,$host],
+AS_CASE([$have_flexdll_h,$supports_shared_libraries,$target],
  [no,true,*-*-cygwin*],
    [supports_shared_libraries=false
    AC_MSG_WARN([flexdll.h not found: shared library support disabled.])],
  [no,*,*-w64-mingw32*|no,*,*-pc-windows],
    [AC_MSG_ERROR([flexdll.h is required for native Win32])])
 
-AS_CASE([$flexdll_source_dir,$supports_shared_libraries,$flexlink,$host],
+AS_CASE([$flexdll_source_dir,$supports_shared_libraries,$flexlink,$target],
   [,true,,*-*-cygwin*],
     [supports_shared_libraries=false
     AC_MSG_WARN([flexlink not found: shared library support disabled.])],
@@ -1003,7 +1063,7 @@ AS_CASE([$flexdll_source_dir,$supports_shared_libraries,$flexlink,$host],
 
 mkexe_cmd_exp="$CC"
 
-AS_CASE([$ocaml_cc_vendor,$host],
+AS_CASE([$ocaml_cc_vendor,$target],
   [*,x86_64-*-darwin*],
     [oc_ldflags='-Wl,-no_compact_unwind';
     AC_DEFINE([HAS_ARCH_CODE32], [1])],
@@ -1021,7 +1081,7 @@ AS_CASE([$ocaml_cc_vendor,$host],
     )
     ostype="Cygwin"],
   [*,*-*-mingw32*],
-    [AS_CASE([$host],
+    [AS_CASE([$target],
       [i686-*-*], [oc_dll_ldflags="-static-libgcc"])
     ostype="Win32"
     toolchain="mingw"
@@ -1049,7 +1109,9 @@ AS_CASE([$ocaml_cc_vendor,$host],
     [oc_ldflags='-brtl -bexpfull'
     AC_DEFINE([HAS_ARCH_CODE32], [1])],
   [gcc-*,powerpc-*-linux*],
-    [oc_ldflags="-mbss-plt"])
+    [oc_ldflags="-mbss-plt"],
+  [*,*-*-none|*,*-*-elf*],
+    [ostype="None"])
 
 ## Program to use to install files
 AC_PROG_INSTALL
@@ -1066,7 +1128,7 @@ AC_SEARCH_LIBS([cos], [m],
 # Checks for header files
 
 # Don't check for unistd.h on Windows
-AS_CASE([$host],
+AS_CASE([$target],
   [*-*-mingw32*|*-pc-windows], [],
   [AC_CHECK_HEADERS([unistd.h],[AC_DEFINE([HAS_UNISTD])])])
 
@@ -1165,7 +1227,7 @@ AS_IF([! $cc_supports_atomic],
 # Full support for thread local storage
 # macOS and MinGW-w64 have problems with thread local storage accessed from DLLs
 
-AS_CASE([$host],
+AS_CASE([$target],
   [*-apple-darwin*|*-mingw32*], [],
   [AC_DEFINE([HAS_FULL_THREAD_VARIABLES])]
 )
@@ -1181,7 +1243,7 @@ natdynlinkopts=""
 
 AS_IF([test x"$enable_shared" != "xno"],
   [mkdll=''
-  AS_CASE([$host],
+  AS_CASE([$target],
     [x86_64-apple-darwin*],
       [mkdll_flags=\
 '-shared -undefined dynamic_lookup -Wl,-no_compact_unwind -Wl,-w'
@@ -1209,7 +1271,7 @@ AS_IF([test x"$enable_shared" != "xno"],
     [[*-*-linux*|*-*-freebsd[3-9]*|*-*-freebsd[1-9][0-9]*\
     |*-*-openbsd*|*-*-netbsd*|*-*-dragonfly*|*-*-gnu*|*-*-haiku*]],
       [sharedlib_cflags="-fPIC"
-       AS_CASE([$ocaml_cc_vendor,$host],
+       AS_CASE([$ocaml_cc_vendor,$target],
          [gcc-*,powerpc-*-linux*],
            [mkdll_flags='-shared -mbss-plt'],
          [[*,i[3456]86-*]],
@@ -1217,7 +1279,7 @@ AS_IF([test x"$enable_shared" != "xno"],
            # See https://github.com/ocaml/ocaml/issues/9800
            [mkdll_flags='-shared -Wl,-z,notext'],
          [mkdll_flags='-shared'])
-       AS_CASE([$host],
+       AS_CASE([$target],
          [[*-*-openbsd7.[3-9]|*-*-openbsd[89].*]],
            [mkdll_flags="${mkdll_flags} -Wl,--no-execute-only"])
       oc_ldflags="$oc_ldflags -Wl,-E"
@@ -1237,14 +1299,14 @@ AS_IF([test -z "$mkmaindll"],
 # Make sure code sections in OCaml-generated executables are readable
 # (required for marshaling of function closures)
 
-AS_CASE([$host],
+AS_CASE([$target],
   [[*-*-openbsd7.[3-9]|*-*-openbsd[89].*]],
     [oc_ldflags="$oc_ldflags -Wl,--no-execute-only"
      natdynlinkopts="$natdynlinkopts -Wl,--no-execute-only"])
 
 # Disable control flow integrity
 
-AS_CASE([$host],
+AS_CASE([$target],
   [[*-*-openbsd7.[4-9]|*-*-openbsd[89].*]],
     [oc_ldflags="$oc_ldflags -Wl,-z,nobtcfi"
      natdynlinkopts="$natdynlinkopts -Wl,-z,nobtcfi"])
@@ -1255,7 +1317,7 @@ AS_CASE([$host],
 natdynlink=false
 
 AS_IF([test x"$supports_shared_libraries" = 'xtrue'],
-  [AS_CASE(["$host"],
+  [AS_CASE(["$target"],
     [*-*-cygwin*], [natdynlink=true],
     [*-*-mingw32*], [natdynlink=true],
     [*-pc-windows], [natdynlink=true],
@@ -1297,7 +1359,7 @@ AS_CASE([$enable_native_toplevel,$natdynlink],
   [install_ocamlnat=false])
 
 # Try to work around the Skylake/Kaby Lake processor bug.
-AS_CASE(["$ocaml_cc_vendor,$host"],
+AS_CASE(["$ocaml_cc_vendor,$target"],
   [*gcc*,x86_64-*|*gcc*,i686-*],
     [OCAML_CC_HAS_FNO_TREE_VRP
     AS_IF([$cc_has_fno_tree_vrp],
@@ -1318,7 +1380,7 @@ system=unknown
 # preserving $arch = 'none' <=> $system = 'unknown'
 has_native_backend=no
 native_ldflags=""
-AS_CASE([$host],
+AS_CASE([$target],
   [[i[3456]86-*-linux*]],
     [arch=i386; system=linux],
   [[i[3456]86-*-freebsd*]],
@@ -1415,7 +1477,19 @@ AS_CASE([$host],
   [x86_64-*-cygwin*],
     [has_native_backend=yes; arch=amd64; system=cygwin],
   [riscv64-*-linux*],
-    [has_native_backend=yes; arch=riscv; model=riscv64; system=linux]
+    [has_native_backend=yes; arch=riscv; model=riscv64; system=linux],
+  [aarch64-*-none|arm64-*-none|aarch64-*-elf*|arm64-*-elf*],
+    [has_native_backend=yes; arch=arm64; system=none],
+  [powerpc64le*-*-none|powerpc64le*-*-elf*],
+    [has_native_backend=yes; arch=power; model=ppc64le; system=none],
+  [powerpc64*-*-none|powerpc64*-*-elf*],
+    [has_native_backend=yes; arch=power; model=ppc64; system=none],
+  [riscv64-*-none|riscv64-*-elf*],
+    [has_native_backend=yes; arch=riscv; model=riscv64; system=none],
+  [s390x*-*-none|s390x*-*-elf*],
+    [has_native_backend=yes; arch=s390x; model=z10; system=none],
+  [x86_64-*-none|x86_64-*-elf*],
+    [has_native_backend=yes; arch=amd64; system=none]
 )
 
 AS_CASE([$arch],
@@ -1454,10 +1528,11 @@ AS_IF([$natdynlink],
   [natdynlink_archive=""])
 
 AC_DEFINE_UNQUOTED([OCAML_OS_TYPE], ["$ostype"])
+target_os_type="$ostype"
 
-AC_CHECK_TOOL([DIRECT_LD],[ld])
+AC_CHECK_TARGET_TOOL([DIRECT_LD],[ld])
 AS_IF([test -z "$PARTIALLD"],
-  [AS_CASE(["$host,$ocaml_cc_vendor"],
+  [AS_CASE(["$target,$ocaml_cc_vendor"],
     [x86_64-*-darwin*,gcc-*], [PACKLD_FLAGS=' -arch x86_64'],
     [powerpc64le*-*-linux*,gcc-*], [PACKLD_FLAGS=' -m elf64lppc'],
     [powerpc*-*-linux*,gcc-*],
@@ -1492,7 +1567,7 @@ AS_CASE([$arch],
   [amd64|arm64|s390x|none],
     # ocamlopt generates PIC code or doesn't generate code at all
     [],
-  [AS_CASE([$host],
+  [AS_CASE([$target],
     # expected to match "*-linux-musl" as well as "*-linux-musleabi*"
     [*-linux-musl*],
       # Alpine and other musl-based Linux distributions
@@ -1626,7 +1701,7 @@ AC_CHECK_FUNC([issetugid], [AC_DEFINE([HAS_ISSETUGID])])
 ## On MacOS clock_gettime's CLOCK_MONOTONIC flag is not actually monotonic.
 ## mach_timebase_info and mach_absolute_time are used instead.
 
-AS_CASE([$host],
+AS_CASE([$target],
   [*-*-windows],
     [has_monotonic_clock=true],
   [*-apple-darwin*], [
@@ -1662,7 +1737,7 @@ AS_CASE([$host],
 # clock source is missing.
 AS_IF([test "x$enable_instrumented_runtime" != "xno" ],
   [
-    AS_CASE([$host],
+    AS_CASE([$target],
     [sparc-sun-solaris*],
       [instrumented_runtime=false],
     [*-*-windows],
@@ -1852,7 +1927,7 @@ AS_IF([$tsan],
 
 sockets=true
 
-AS_CASE([$host],
+AS_CASE([$target],
   [*-*-mingw32*],
     [cclibs="$cclibs -lws2_32"
     AC_SEARCH_LIBS([socket], [ws2_32])
@@ -1880,7 +1955,7 @@ AS_IF([$sockets], [AC_DEFINE([HAS_SOCKETS])])
 
 ## socklen_t
 
-AS_CASE([$host],
+AS_CASE([$target],
   [*-*-mingw32*|*-pc-windows],
     [AC_CHECK_TYPE([socklen_t], [AC_DEFINE([HAS_SOCKLEN_T])], [],
       [#include <ws2tcpip.h>])],
@@ -1891,7 +1966,7 @@ AC_CHECK_FUNC([inet_aton], [AC_DEFINE([HAS_INET_ATON])])
 
 ## Unix domain sockets support on Windows
 
-AS_CASE([$host],
+AS_CASE([$target],
   [*-*-mingw32*|*-pc-windows],
     [AC_CHECK_HEADERS([afunix.h], [AC_DEFINE([HAS_AFUNIX_H])], [],
       [#include <winsock2.h>])])
@@ -1900,7 +1975,7 @@ AS_CASE([$host],
 
 ipv6=true
 
-AS_CASE([$host],
+AS_CASE([$target],
   [*-*-mingw32*|*-pc-windows],
     [AC_CHECK_TYPE(
       [struct sockaddr_in6], [], [ipv6=false], [#include <ws2tcpip.h>])],
@@ -1940,7 +2015,7 @@ AC_CHECK_DECL([system], [AC_DEFINE([HAS_SYSTEM])], [], [[#include <stdlib.h>]])
 ## Note: this was defined in config/s-nt.h but the autoconf macros do not
 # seem to detect it properly on Windows so we hardcode the definition
 # of HAS_UTIME on Windows but this will probably need to be clarified
-AS_CASE([$host],
+AS_CASE([$target],
   [*-*-mingw32*|*-pc-windows], [AC_DEFINE([HAS_UTIME])],
   [AC_CHECK_HEADER([sys/types.h],
     [AC_CHECK_HEADER([utime.h],
@@ -2017,7 +2092,7 @@ AC_CHECK_FUNC([setitimer],
 ## gethostname
 # Note: detection fails on Windows so hardcoding the result
 # (should be debugged later)
-AS_CASE([$host],
+AS_CASE([$target],
   [*-*-mingw32*|*-pc-windows], [AC_DEFINE([HAS_GETHOSTNAME])],
   [AC_CHECK_FUNC([gethostname], [AC_DEFINE([HAS_GETHOSTNAME])])])
 
@@ -2041,7 +2116,7 @@ AC_CHECK_FUNC([mktime], [AC_DEFINE([HAS_MKTIME])])
 
 ## setsid
 
-AS_CASE([$host],
+AS_CASE([$target],
   [*-cygwin|*-*-mingw32*|*-pc-windows], [],
   [AC_CHECK_FUNC([setsid], [AC_DEFINE([HAS_SETSID])])])
 
@@ -2057,7 +2132,7 @@ AC_CHECK_FUNC([setenv],
 ## newlocale() and <locale.h>
 # Note: the detection fails on msvc so we hardcode the result
 # (should be debugged later)
-AS_CASE([$host],
+AS_CASE([$target],
   [*-pc-windows], [AC_DEFINE([HAS_LOCALE_H])],
   [AC_CHECK_HEADER([locale.h],
     [AC_CHECK_FUNC([newlocale],
@@ -2072,13 +2147,13 @@ AC_CHECK_HEADER([xlocale.h],
 ## strtod_l
 # Note: not detected on MSVC so hardcoding the result
 # (should be debugged later)
-AS_CASE([$host],
+AS_CASE([$target],
   [*-pc-windows], [AC_DEFINE([HAS_STRTOD_L])],
   [AC_CHECK_FUNC([strtod_l], [AC_DEFINE([HAS_STRTOD_L])])])
 
 ## shared library support
 AS_IF([$supports_shared_libraries],
-  [AS_CASE([$host],
+  [AS_CASE([$target],
     [*-*-mingw32*|*-pc-windows|*-*-cygwin*],
       [DLLIBS=""],
     [AC_CHECK_FUNC([dlopen],
@@ -2104,7 +2179,7 @@ AC_CHECK_HEADER([sys/mman.h],
 AC_CHECK_FUNC([pwrite], [AC_DEFINE([HAS_PWRITE])])
 
 ## -fdebug-prefix-map support by the C compiler
-AS_CASE([$ocaml_cc_vendor,$host],
+AS_CASE([$ocaml_cc_vendor,$target],
   [*,*-*-mingw32*], [cc_has_debug_prefix_map=false],
   [*,*-pc-windows], [cc_has_debug_prefix_map=false],
   [xlc*,powerpc-ibm-aix*], [cc_has_debug_prefix_map=false],
@@ -2207,7 +2282,7 @@ AC_CHECK_HEADER([spawn.h],
   [AC_CHECK_FUNC([posix_spawn],
     [AC_CHECK_FUNC([posix_spawnp], [AC_DEFINE([HAS_POSIX_SPAWN])])])])
 
-AC_PATH_TOOL([PKG_CONFIG], [pkg-config], [false])
+AC_PATH_TARGET_TOOL([PKG_CONFIG], [pkg-config], [false])
 
 ## ZSTD compression library
 
@@ -2238,9 +2313,9 @@ AS_IF([test x"$with_zstd" != "xno"],
 # library available, but not have the DLL in PATH. This then causes the build to
 # fail as soon as ocamlrun is first executed. This check avoids automatically
 # enabling zstd when the resulting executable doesn't actually work.
-AS_CASE([$host],
+AS_CASE([$target],
   [*-w64-mingw32*|*-pc-windows],
-    [check_zstd_runs=$host_runnable],
+    [check_zstd_runs=$target_runnable],
   [check_zstd_runs=false])
 
 AS_IF([test x"$zstd_status" = "xok"],[
@@ -2308,7 +2383,7 @@ AS_CASE([$enable_debug_runtime],
 
 ## Determine how to link with the POSIX threads library
 
-AS_CASE([$host],
+AS_CASE([$target],
   [*-*-mingw32*],
     [PTHREAD_LIBS="-l:libpthread.a -lgcc_eh"],
   [*-pc-windows],
@@ -2373,7 +2448,7 @@ AS_CASE([$enable_systhreads,$enable_unix_lib],
 as_has_debug_prefix_map=false
 asm_cfi_supported=false
 AS_IF([$native_compiler],
-  [AS_CASE([$host],
+  [AS_CASE([$target],
     [*-*-mingw32*|*-pc-windows], [],
     [OCAML_AS_HAS_DEBUG_PREFIX_MAP
     OCAML_AS_HAS_CFI_DIRECTIVES])])
@@ -2381,7 +2456,7 @@ AS_IF([$native_compiler],
 ## Frame pointers
 
 AS_IF([test x"$enable_frame_pointers" = "xyes"],
-  [AS_CASE(["$host,$ocaml_cc_vendor"],
+  [AS_CASE(["$target,$ocaml_cc_vendor"],
     [x86_64-*-linux*,gcc-*|x86_64-*-linux*,clang-*],
       [common_cflags="$common_cflags -g  -fno-omit-frame-pointer"
       frame_pointers=true
@@ -2544,7 +2619,7 @@ oc_cppflags="$common_cppflags $internal_cppflags"
 ocamlc_cflags="$ocamlc_cflags $common_cflags $sharedlib_cflags $CFLAGS"
 ocamlc_cppflags="$common_cppflags $CPPFLAGS"
 
-AS_CASE([$host],
+AS_CASE([$target],
   [*-*-mingw32*],
     [cclibs="$cclibs -lole32 -luuid -lversion"],
   [*-pc-windows],
@@ -2563,7 +2638,7 @@ AS_IF([test x"$libdir" = x'${exec_prefix}/lib'],
 AS_IF([test x"$mandir" = x'${datarootdir}/man'],
   [mandir='${prefix}/man'])
 
-AS_CASE([$host],
+AS_CASE([$target],
   [*-*-mingw32*|*-pc-windows],
     [AS_CASE([$WINDOWS_UNICODE_MODE],
       [ansi],
@@ -2588,7 +2663,7 @@ AS_IF([test x"$prefix" = "xNONE"],
 # Define a few macros that were defined in config/m-nt.h
 # but whose value is not guessed properly by configure
 # (all this should be understood and fixed)
-AS_CASE([$host],
+AS_CASE([$target],
   [*-*-mingw32*],
     [AC_DEFINE([HAS_BROKEN_PRINTF])
     AC_DEFINE([HAS_STRERROR])
diff --git a/middle_end/closure/closure.ml b/middle_end/closure/closure.ml
index 880773fbac09..b78feab118c9 100644
--- a/middle_end/closure/closure.ml
+++ b/middle_end/closure/closure.ml
@@ -1058,9 +1058,9 @@ let rec close ({ backend; fenv; cenv ; mutable_vars } as env) lam =
         | Word_size -> make_const_int (8*B.size_int)
         | Int_size -> make_const_int (8*B.size_int - 1)
         | Max_wosize -> make_const_int ((1 lsl ((8*B.size_int) - 10)) - 1 )
-        | Ostype_unix -> make_const_bool (Sys.os_type = "Unix")
-        | Ostype_win32 -> make_const_bool (Sys.os_type = "Win32")
-        | Ostype_cygwin -> make_const_bool (Sys.os_type = "Cygwin")
+        | Ostype_unix -> make_const_bool (Config.target_os_type = "Unix")
+        | Ostype_win32 -> make_const_bool (Config.target_os_type = "Win32")
+        | Ostype_cygwin -> make_const_bool (Config.target_os_type = "Cygwin")
         | Backend_type ->
             make_const_int 0 (* tag 0 is the same as Native here *)
       in
diff --git a/otherlibs/Makefile.otherlibs.common b/otherlibs/Makefile.otherlibs.common
index 53667c795488..31bbb9a52ee6 100644
--- a/otherlibs/Makefile.otherlibs.common
+++ b/otherlibs/Makefile.otherlibs.common
@@ -34,7 +34,7 @@ COMPFLAGS=-absname -w +a-4-9-41-42-44-45-48 -warn-error +A -bin-annot -g \
 ifeq "$(FLAMBDA)" "true"
 OPTCOMPFLAGS += -O3
 endif
-MKLIB=$(OCAMLRUN) $(ROOTDIR)/tools/ocamlmklib
+MKLIB=$(OCAMLRUN) $(ROOTDIR)/tools/ocamlmklib$(EXE)
 
 # Variables that must be defined by individual libraries:
 # LIBNAME
diff --git a/runtime/amd64.S b/runtime/amd64.S
index 49c712b16753..be0856a72b2a 100644
--- a/runtime/amd64.S
+++ b/runtime/amd64.S
@@ -1386,7 +1386,7 @@ G(caml_negf_mask):
 G(caml_absf_mask):
         .quad   0x7FFFFFFFFFFFFFFF, 0xFFFFFFFFFFFFFFFF
 
-#if defined(SYS_linux)
+#if defined(SYS_linux) || defined(SYS_none)
     /* Mark stack as non-executable, PR#4564 */
         .section .note.GNU-stack,"",%progbits
 #endif
diff --git a/runtime/unix.c b/runtime/unix.c
index b5fd4de17b9c..c0677e09ace0 100644
--- a/runtime/unix.c
+++ b/runtime/unix.c
@@ -27,13 +27,12 @@
 #include <errno.h>
 #include <sys/ioctl.h>
 #include <sys/types.h>
+#include "caml/config.h"
 #ifdef HAS_GETTIMEOFDAY
 #include <sys/time.h>
 #endif
 #include <sys/stat.h>
 #include <fcntl.h>
-#include <errno.h>
-#include "caml/config.h"
 #if defined(SUPPORT_DYNAMIC_LINKING) && !defined(BUILDING_LIBCAMLRUNS)
 #define WITH_DYNAMIC_LINKING
 #ifdef __CYGWIN__
@@ -47,7 +46,7 @@
 #endif
 #ifdef HAS_POSIX_MONOTONIC_CLOCK
 #include <time.h>
-#elif HAS_CLOCK_GETTIME_NSEC_NP
+#elif defined(HAS_CLOCK_GETTIME_NSEC_NP)
 #include <time.h>
 #endif
 #ifdef HAS_DIRENT
diff --git a/stdlib/Makefile b/stdlib/Makefile
index 50f825a1b322..a7f2e60a7aa0 100644
--- a/stdlib/Makefile
+++ b/stdlib/Makefile
@@ -96,10 +96,7 @@ endif
 .INTERMEDIATE: tmpheader.exe
 tmpheader.exe: $(HEADERPROGRAM).$(O)
 	$(V_MKEXE)$(call MKEXE_VIA_CC,$@,$^)
-# FIXME This is wrong - mingw could invoke strip; MSVC equivalent?
-ifneq "$(UNIX_OR_WIN32)" "win32"
-	strip $@
-endif
+	$(STRIP) $@
 
 stdlib.cma: $(OBJS)
 	$(V_LINKC)$(CAMLC) -a -o $@ $^
diff --git a/utils/config.common.ml.in b/utils/config.common.ml.in
index 15043dae8432..ef9f4da4d9fa 100644
--- a/utils/config.common.ml.in
+++ b/utils/config.common.ml.in
@@ -101,7 +101,7 @@ let configuration_variables () =
   p "ext_asm" ext_asm;
   p "ext_lib" ext_lib;
   p "ext_dll" ext_dll;
-  p "os_type" Sys.os_type;
+  p "os_type" target_os_type;
   p "default_executable_name" default_executable_name;
   p_bool "systhread_supported" systhread_supported;
   p "host" host;
diff --git a/utils/config.fixed.ml b/utils/config.fixed.ml
index 9374f4464acc..99396610d67f 100644
--- a/utils/config.fixed.ml
+++ b/utils/config.fixed.ml
@@ -57,6 +57,8 @@ let tsan = false
 let architecture = "none"
 let model = "default"
 let system = "unknown"
+let target_os_type =
+  "The boot compiler should not be using Config.target_os_type"
 let asm = boot_cannot_call "the assembler"
 let asm_cfi_supported = false
 let with_frame_pointers = false
diff --git a/utils/config.generated.ml.in b/utils/config.generated.ml.in
index 1d22c1d7f619..0dfa638270a3 100644
--- a/utils/config.generated.ml.in
+++ b/utils/config.generated.ml.in
@@ -71,6 +71,7 @@ let native_compiler = @native_compiler@
 let architecture = {@QS@|@arch@|@QS@}
 let model = {@QS@|@model@|@QS@}
 let system = {@QS@|@system@|@QS@}
+let target_os_type = {@QS@|@target_os_type@|@QS@}
 
 let asm = {@QS@|@AS@|@QS@}
 let asm_cfi_supported = @asm_cfi_supported@
diff --git a/utils/config.mli b/utils/config.mli
index f1e1d04bd439..000d18b88f1c 100644
--- a/utils/config.mli
+++ b/utils/config.mli
@@ -167,6 +167,12 @@ val model: string
 val system: string
 (** Name of operating system for the native-code compiler *)
 
+val target_os_type: string
+(** Operating system targetted by the native-code compiler. One of
+-  ["Unix"] (for all Unix versions, including Linux and Mac OS X),
+-  ["Win32"] (for MS-Windows, OCaml compiled with MSVC++ or MinGW-w64),
+-  ["Cygwin"] (for MS-Windows, OCaml compiled with Cygwin). *)
+
 val asm: string
 (** The assembler (and flags) to use for assembling
     ocamlopt-generated code. *)