libobjc/configure.ac - gcc - Git at Google

 # Process this file with autoconf to produce a configure script.
 #   Copyright (C) 1994-2021 Free Software Foundation, Inc.
 #   Originally contributed by Dave Love (d.love@dl.ac.uk).
 #
 #This file is part of GCC.
 #
 #GCC is free software; you can redistribute it and/or modify
 #it under the terms of the GNU General Public License as published by
 #the Free Software Foundation; either version 3, or (at your option)
 #any later version.
 #
 #GCC is distributed in the hope that it will be useful,
 #but WITHOUT ANY WARRANTY; without even the implied warranty of
 #MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 #GNU General Public License for more details.
 #
 #You should have received a copy of the GNU General Public License
 #along with GCC; see the file COPYING3.  If not see
 #<http://www.gnu.org/licenses/>.

 AC_INIT(package-unused, version-unused,, libobjc)
 AC_CONFIG_SRCDIR([objc/objc.h])
 GCC_TOPLEV_SUBDIRS

 # We need the following definitions because AC_PROG_LIBTOOL relies on them
 PACKAGE=libobjc
 # Version is pulled out to make it a bit easier to change using sed.
 VERSION=4:0:0
 AC_SUBST(VERSION)

 # This works around the fact that libtool configuration may change LD
 # for this particular configuration, but some shells, instead of
 # keeping the changes in LD private, export them just because LD is
 # exported.
 ORIGINAL_LD_FOR_MULTILIBS=$LD

 # -------
 # Options
 # -------

 # We use these options to decide which functions to include.
 AC_ARG_WITH(target-subdir,
 [  --with-target-subdir=SUBDIR
                            configuring in a subdirectory])
 AC_ARG_WITH(cross-host,
 [  --with-cross-host=HOST  configuring with a cross compiler])

 AC_MSG_CHECKING([for --enable-version-specific-runtime-libs])
 AC_ARG_ENABLE(version-specific-runtime-libs,
 [  --enable-version-specific-runtime-libs    Specify that runtime libraries should be installed in a compiler-specific directory ],
 [case "$enableval" in
  yes) version_specific_libs=yes ;;
  no)  version_specific_libs=no ;;
  *)   AC_MSG_ERROR([Unknown argument to enable/disable version-specific libs]);;
  esac],
 [version_specific_libs=no])
 AC_MSG_RESULT($version_specific_libs)

 # -----------
 # Directories
 # -----------

 # Find the rest of the source tree framework.
 AM_ENABLE_MULTILIB(, ..)

 AC_CANONICAL_SYSTEM
 ACX_NONCANONICAL_TARGET

 # Export source directory.
 # These need to be absolute paths, yet at the same time need to
 # canonicalize only relative paths, because then amd will not unmount
 # drives. Thus the use of PWDCMD: set it to 'pawd' or 'amq -w' if using amd.
 case $srcdir in
   [\\/$]* | ?:[\\/]*) glibcpp_srcdir=${srcdir} ;;
   *) glibcpp_srcdir=`cd "$srcdir" && ${PWDCMD-pwd} || echo "$srcdir"` ;;
 esac
 AC_SUBST(glibcpp_srcdir)

 GCC_WITH_TOOLEXECLIBDIR

 # Calculate toolexeclibdir
 # Also toolexecdir, though it's only used in toolexeclibdir
 case ${version_specific_libs} in
   yes)
     # Need the gcc compiler version to know where to install libraries
     # and header files if --enable-version-specific-runtime-libs option
     # is selected.
     toolexecdir='$(libdir)/gcc/$(target_noncanonical)'
     toolexeclibdir='$(toolexecdir)/$(gcc_version)$(MULTISUBDIR)'
     ;;
   no)
     if test -n "$with_cross_host" &&
        test x"$with_cross_host" != x"no"; then
       # Install a library built with a cross compiler in tooldir, not libdir.
       toolexecdir='$(exec_prefix)/$(target_noncanonical)'
       case ${with_toolexeclibdir} in
 	no)
 	  toolexeclibdir='$(toolexecdir)/lib'
 	  ;;
 	*)
 	  toolexeclibdir=${with_toolexeclibdir}
 	  ;;
       esac
     else
       toolexecdir='$(libdir)/gcc-lib/$(target_noncanonical)'
       toolexeclibdir='$(libdir)'
     fi
     multi_os_directory=`$CC -print-multi-os-directory`
     case $multi_os_directory in
       .) ;; # Avoid trailing /.
       *) toolexeclibdir=$toolexeclibdir/$multi_os_directory ;;
     esac
     ;;
 esac
 AC_SUBST(toolexecdir)
 AC_SUBST(toolexeclibdir)

 # Figure out if we want to name the include directory and the
 #  library name changes differently.
 includedirname=include
 libsuffix=
 case "${host}" in
   *-darwin*)
     # Darwin is the only target so far that needs a different include directory.
     includedirname=include-gnu-runtime
     libsuffix=-gnu
     ;;
 esac
 AC_SUBST(includedirname)
 AC_SUBST(libsuffix)

 AC_CONFIG_HEADERS(config.h)

 # --------
 # Programs
 # --------

 GCC_NO_EXECUTABLES

 # We must force CC to /not/ be a precious variable; otherwise
 # the wrong, non-multilib-adjusted value will be used in multilibs.
 # As a side effect, we have to subst CFLAGS ourselves.
 m4_rename([_AC_ARG_VAR_PRECIOUS],[real_PRECIOUS])
 m4_define([_AC_ARG_VAR_PRECIOUS],[])
 AC_PROG_CC
 m4_rename_force([real_PRECIOUS],[_AC_ARG_VAR_PRECIOUS])

 # extra LD Flags which are required for targets
 ACX_LT_HOST_FLAGS
 case "${host}" in
   *-darwin*)
     # Darwin needs -single_module when linking libobjc
     extra_ldflags_libobjc='$(lt_host_flags) -Wl,-single_module'
     ;;
   *-cygwin*|*-mingw*)
     # Tell libtool to build DLLs on Windows
     extra_ldflags_libobjc='$(lt_host_flags)'
     ;;
 esac
 AC_SUBST(extra_ldflags_libobjc)

 # Add CET specific flags if CET is enabled
 GCC_CET_FLAGS(CET_FLAGS)
 XCFLAGS="$XCFLAGS $CET_FLAGS"

 AC_SUBST(CFLAGS)
 AC_SUBST(XCFLAGS)

 AC_CHECK_TOOL(AS, as)
 AC_CHECK_TOOL(AR, ar)
 AC_CHECK_TOOL(RANLIB, ranlib, :)
 AC_PROG_INSTALL

 AM_MAINTAINER_MODE

 # Enable Win32 DLL on MS Windows - FIXME
 AC_LIBTOOL_WIN32_DLL

 AC_PROG_LIBTOOL

 AM_PROG_CC_C_O

 AC_PROG_MAKE_SET

 # -------
 # Headers
 # -------

 # Sanity check for the cross-compilation case:
 AC_CHECK_HEADER(stdio.h,:,
   [AC_MSG_ERROR([Can't find stdio.h.
 You must have a usable C system for the target already installed, at least
 including headers and, preferably, the library, before you can configure
 the Objective C runtime system.  If necessary, install gcc now with
 \`LANGUAGES=c', then the target library, then build with \`LANGUAGES=objc'.])])

 AC_HEADER_STDC

 AC_CHECK_HEADERS(sched.h)

 # -----------
 # Miscellanea
 # -----------

 # Check if we have thread-local storage
 GCC_CHECK_TLS

 gt_BITFIELD_TYPE_MATTERS

 # -----------
 # boehm-gc
 # -----------

 AC_ARG_ENABLE(objc-gc,
 [AS_HELP_STRING([--enable-objc-gc],
 		[enable use of Boehm's garbage collector with the
 		 GNU Objective-C runtime])],,enable_objc_gc=no)
 AC_ARG_WITH([target-bdw-gc],
 [AS_HELP_STRING([--with-target-bdw-gc=PATHLIST],
 		[specify prefix directory for installed bdw-gc package.
 		 Equivalent to --with-target-bdw-gc-include=PATH/include
 		 plus --with-target-bdw-gc-lib=PATH/lib])])
 AC_ARG_WITH([target-bdw-gc-include],
 [AS_HELP_STRING([--with-target-bdw-gc-include=PATHLIST],
 		[specify directories for installed bdw-gc include files])])
 AC_ARG_WITH([target-bdw-gc-lib],
 [AS_HELP_STRING([--with-target-bdw-gc-lib=PATHLIST],
 		[specify directories for installed bdw-gc library])])

 case "$enable_objc_gc" in
 no)
   use_bdw_gc=no
   ;;
 *)
   AC_MSG_CHECKING([for bdw garbage collector])
   if test "x$with_target_bdw_gc$with_target_bdw_gc_include$with_target_bdw_gc_lib" = x; then
     dnl no bdw-gw options, assuming bdw-gc in default locations
     BDW_GC_CFLAGS=
     BDW_GC_LIBS="-lgc"
   else
     dnl bdw-gw options passed by configure flags
     if test "x$with_target_bdw_gc_include" = x && test "x$with_target_bdw_gc_lib" != x; then
       AC_MSG_ERROR([found --with-target-bdw-gc-lib but --with-target-bdw-gc-include missing])
     elif test "x$with_target_bdw_gc_include" != x && test "x$with_target_bdw_gc_lib" = x; then
       AC_MSG_ERROR([found --with-target-bdw-gc-include but --with-target-bdw-gc-lib missing])
     else
       AC_MSG_RESULT([using paths configured with --with-target-bdw-gc options])
     fi
     mldir=`${CC-gcc} --print-multi-directory 2>/dev/null`
     bdw_val=
     if test "x$with_target_bdw_gc" != x; then
       for i in `echo $with_target_bdw_gc | tr ',' ' '`; do
         case "$i" in
           *=*) sd=${i%%=*}; d=${i#*=} ;;
           *) sd=.; d=$i ;;
         esac
         if test "$mldir" = "$sd"; then
           bdw_val=$d
         fi
       done
       if test "x$bdw_val" = x; then
         AC_MSG_ERROR([no multilib path ($mldir) found in --with-target-bdw-gc])
       fi
       bdw_inc_dir="$bdw_val/include"
       bdw_lib_dir="$bdw_val/lib"
     fi
     bdw_val=
     if test "x$with_target_bdw_gc_include" != x; then
       for i in `echo $with_target_bdw_gc_include | tr ',' ' '`; do
         case "$i" in
           *=*) sd=${i%%=*}; d=${i#*=} ;;
           *) sd=.; d=$i; fallback=$i ;;
         esac
         if test "$mldir" = "$sd"; then
           bdw_val=$d
         fi
       done
       if test "x$bdw_val" = x && test "x$bdw_inc_dir" = x && test "x$fallback" != x; then
         bdw_inc_dir="$fallback"
       elif test "x$bdw_val" = x; then
         AC_MSG_ERROR([no multilib path ($mldir) found in --with-target-bdw-gc-include])
       else
         bdw_inc_dir="$bdw_val"
       fi
     fi
     bdw_val=
     if test "x$with_target_bdw_gc_lib" != x; then
       for i in `echo $with_target_bdw_gc_lib | tr ',' ' '`; do
         case "$i" in
           *=*) sd=${i%%=*}; d=${i#*=} ;;
           *) sd=.; d=$i ;;
         esac
         if test "$mldir" = "$sd"; then
           bdw_val=$d
         fi
       done
       if test "x$bdw_val" = x; then
         AC_MSG_ERROR([no multilib path ($mldir) found in --with-target-bdw-gc-lib])
       fi
       bdw_lib_dir="$bdw_val"
     fi
     if test "x$bdw_inc_dir" = x; then
       AC_MSG_ERROR([no multilib path ($mldir) found in --with-target-bdw-gc-include])
     fi
     if test "x$bdw_lib_dir" = x; then
       AC_MSG_ERROR([no multilib path ($mldir) found in --with-target-bdw-gc-lib])
     fi
     BDW_GC_CFLAGS="-I$bdw_inc_dir"
     if test -f $bdw_lib_dir/libgc.la; then
       BDW_GC_LIBS="$bdw_lib_dir/libgc.la"
     else
       BDW_GC_LIBS="-L$bdw_lib_dir -lgc"
     fi
     AC_MSG_RESULT([found])
   fi

   case "$BDW_GC_LIBS" in
   *libgc.la)
     use_bdw_gc=yes
     ;;
   *)
     AC_MSG_CHECKING([for system boehm-gc])
     save_CFLAGS=$CFLAGS
     save_LIBS=$LIBS
     CFLAGS="$CFLAGS $BDW_GC_CFLAGS"
     LIBS="$LIBS $BDW_GC_LIBS"
     dnl the link test is not good enough for ARM32 multilib detection,
     dnl first check to link, then to run
     AC_LINK_IFELSE(
       [AC_LANG_PROGRAM([#include <gc/gc.h>],[GC_init()])],
       [
         AC_RUN_IFELSE([AC_LANG_SOURCE([[
           #include <gc/gc.h>
           int main() {
             GC_init();
             return 0;
           }
           ]])],
           [system_bdw_gc_found=yes],
           [system_bdw_gc_found=no],
           dnl assume no system boehm-gc for cross builds ...
           [system_bdw_gc_found=no]
         )
       ],
       [system_bdw_gc_found=no])
     CFLAGS=$save_CFLAGS
     LIBS=$save_LIBS
     if test x$enable_objc_gc = xauto && test x$system_bdw_gc_found = xno; then
       AC_MSG_WARN([system bdw-gc not found, not building libobjc_gc])
       use_bdw_gc=no
     elif test x$enable_objc_gc = xyes && test x$system_bdw_gc_found = xno; then
       AC_MSG_ERROR([system bdw-gc required but not found])
     else
       use_bdw_gc=yes
       AC_MSG_RESULT([found])
     fi
   esac
 esac

 if test "$use_bdw_gc" = no; then
   OBJC_GCFLAGS=''
   OBJC_BOEHM_GC=''
   OBJC_BOEHM_GC_INCLUDES=''
   OBJC_BOEHM_GC_LIBS=''
 else
   OBJC_GCFLAGS='-DOBJC_WITH_GC=1'
   OBJC_BOEHM_GC='libobjc_gc$(libsuffix).la'
   OBJC_BOEHM_GC_INCLUDES=$BDW_GC_CFLAGS
   OBJC_BOEHM_GC_LIBS=$BDW_GC_LIBS
 fi
 AC_SUBST(OBJC_GCFLAGS)
 AC_SUBST(OBJC_BOEHM_GC)
 AC_SUBST(OBJC_BOEHM_GC_INCLUDES)
 AC_SUBST(OBJC_BOEHM_GC_LIBS)

 # Determine what GCC version number to use in filesystem paths.
 GCC_BASE_VER

 # ------
 # Output
 # ------

 if test ${multilib} = yes; then
   multilib_arg="--enable-multilib"
 else
   multilib_arg=
 fi

 AC_CONFIG_FILES([Makefile])
 AC_OUTPUT
	# Process this file with autoconf to produce a configure script.
	# Copyright (C) 1994-2021 Free Software Foundation, Inc.
	# Originally contributed by Dave Love (d.love@dl.ac.uk).
	#
	#This file is part of GCC.
	#
	#GCC is free software; you can redistribute it and/or modify
	#it under the terms of the GNU General Public License as published by
	#the Free Software Foundation; either version 3, or (at your option)
	#any later version.
	#
	#GCC is distributed in the hope that it will be useful,
	#but WITHOUT ANY WARRANTY; without even the implied warranty of
	#MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	#GNU General Public License for more details.
	#
	#You should have received a copy of the GNU General Public License
	#along with GCC; see the file COPYING3. If not see
	#<http://www.gnu.org/licenses/>.

	AC_INIT(package-unused, version-unused,, libobjc)
	AC_CONFIG_SRCDIR([objc/objc.h])
	GCC_TOPLEV_SUBDIRS

	# We need the following definitions because AC_PROG_LIBTOOL relies on them
	PACKAGE=libobjc
	# Version is pulled out to make it a bit easier to change using sed.
	VERSION=4:0:0
	AC_SUBST(VERSION)

	# This works around the fact that libtool configuration may change LD
	# for this particular configuration, but some shells, instead of
	# keeping the changes in LD private, export them just because LD is
	# exported.
	ORIGINAL_LD_FOR_MULTILIBS=$LD

	# -------
	# Options
	# -------

	# We use these options to decide which functions to include.
	AC_ARG_WITH(target-subdir,
	[ --with-target-subdir=SUBDIR
	configuring in a subdirectory])
	AC_ARG_WITH(cross-host,
	[ --with-cross-host=HOST configuring with a cross compiler])

	AC_MSG_CHECKING([for --enable-version-specific-runtime-libs])
	AC_ARG_ENABLE(version-specific-runtime-libs,
	[ --enable-version-specific-runtime-libs Specify that runtime libraries should be installed in a compiler-specific directory ],
	[case "$enableval" in
	yes) version_specific_libs=yes ;;
	no) version_specific_libs=no ;;
	*) AC_MSG_ERROR([Unknown argument to enable/disable version-specific libs]);;
	esac],
	[version_specific_libs=no])
	AC_MSG_RESULT($version_specific_libs)

	# -----------
	# Directories
	# -----------

	# Find the rest of the source tree framework.
	AM_ENABLE_MULTILIB(, ..)

	AC_CANONICAL_SYSTEM
	ACX_NONCANONICAL_TARGET

	# Export source directory.
	# These need to be absolute paths, yet at the same time need to
	# canonicalize only relative paths, because then amd will not unmount
	# drives. Thus the use of PWDCMD: set it to 'pawd' or 'amq -w' if using amd.
	case $srcdir in
	[\\/$]* \| ?:[\\/]*) glibcpp_srcdir=${srcdir} ;;
	*) glibcpp_srcdir=`cd "$srcdir" && ${PWDCMD-pwd} \|\| echo "$srcdir"` ;;
	esac
	AC_SUBST(glibcpp_srcdir)

	GCC_WITH_TOOLEXECLIBDIR

	# Calculate toolexeclibdir
	# Also toolexecdir, though it's only used in toolexeclibdir
	case ${version_specific_libs} in
	yes)
	# Need the gcc compiler version to know where to install libraries
	# and header files if --enable-version-specific-runtime-libs option
	# is selected.
	toolexecdir='$(libdir)/gcc/$(target_noncanonical)'
	toolexeclibdir='$(toolexecdir)/$(gcc_version)$(MULTISUBDIR)'
	;;
	no)
	if test -n "$with_cross_host" &&
	test x"$with_cross_host" != x"no"; then
	# Install a library built with a cross compiler in tooldir, not libdir.
	toolexecdir='$(exec_prefix)/$(target_noncanonical)'
	case ${with_toolexeclibdir} in
	no)
	toolexeclibdir='$(toolexecdir)/lib'
	;;
	*)
	toolexeclibdir=${with_toolexeclibdir}
	;;
	esac
	else
	toolexecdir='$(libdir)/gcc-lib/$(target_noncanonical)'
	toolexeclibdir='$(libdir)'
	fi
	multi_os_directory=`$CC -print-multi-os-directory`
	case $multi_os_directory in
	.) ;; # Avoid trailing /.
	*) toolexeclibdir=$toolexeclibdir/$multi_os_directory ;;
	esac
	;;
	esac
	AC_SUBST(toolexecdir)
	AC_SUBST(toolexeclibdir)

	# Figure out if we want to name the include directory and the
	# library name changes differently.
	includedirname=include
	libsuffix=
	case "${host}" in
	-darwin)
	# Darwin is the only target so far that needs a different include directory.
	includedirname=include-gnu-runtime
	libsuffix=-gnu
	;;
	esac
	AC_SUBST(includedirname)
	AC_SUBST(libsuffix)

	AC_CONFIG_HEADERS(config.h)

	# --------
	# Programs
	# --------

	GCC_NO_EXECUTABLES

	# We must force CC to /not/ be a precious variable; otherwise
	# the wrong, non-multilib-adjusted value will be used in multilibs.
	# As a side effect, we have to subst CFLAGS ourselves.
	m4_rename([_AC_ARG_VAR_PRECIOUS],[real_PRECIOUS])
	m4_define([_AC_ARG_VAR_PRECIOUS],[])
	AC_PROG_CC
	m4_rename_force([real_PRECIOUS],[_AC_ARG_VAR_PRECIOUS])

	# extra LD Flags which are required for targets
	ACX_LT_HOST_FLAGS
	case "${host}" in
	-darwin)
	# Darwin needs -single_module when linking libobjc
	extra_ldflags_libobjc='$(lt_host_flags) -Wl,-single_module'
	;;
	-cygwin\|-mingw)
	# Tell libtool to build DLLs on Windows
	extra_ldflags_libobjc='$(lt_host_flags)'
	;;
	esac
	AC_SUBST(extra_ldflags_libobjc)

	# Add CET specific flags if CET is enabled
	GCC_CET_FLAGS(CET_FLAGS)
	XCFLAGS="$XCFLAGS $CET_FLAGS"

	AC_SUBST(CFLAGS)
	AC_SUBST(XCFLAGS)

	AC_CHECK_TOOL(AS, as)
	AC_CHECK_TOOL(AR, ar)
	AC_CHECK_TOOL(RANLIB, ranlib, :)
	AC_PROG_INSTALL

	AM_MAINTAINER_MODE

	# Enable Win32 DLL on MS Windows - FIXME
	AC_LIBTOOL_WIN32_DLL

	AC_PROG_LIBTOOL

	AM_PROG_CC_C_O

	AC_PROG_MAKE_SET

	# -------
	# Headers
	# -------

	# Sanity check for the cross-compilation case:
	AC_CHECK_HEADER(stdio.h,:,
	[AC_MSG_ERROR([Can't find stdio.h.
	You must have a usable C system for the target already installed, at least
	including headers and, preferably, the library, before you can configure
	the Objective C runtime system. If necessary, install gcc now with
	\`LANGUAGES=c', then the target library, then build with \`LANGUAGES=objc'.])])

	AC_HEADER_STDC

	AC_CHECK_HEADERS(sched.h)

	# -----------
	# Miscellanea
	# -----------

	# Check if we have thread-local storage
	GCC_CHECK_TLS

	gt_BITFIELD_TYPE_MATTERS

	# -----------
	# boehm-gc
	# -----------

	AC_ARG_ENABLE(objc-gc,
	[AS_HELP_STRING([--enable-objc-gc],
	[enable use of Boehm's garbage collector with the
	GNU Objective-C runtime])],,enable_objc_gc=no)
	AC_ARG_WITH([target-bdw-gc],
	[AS_HELP_STRING([--with-target-bdw-gc=PATHLIST],
	[specify prefix directory for installed bdw-gc package.
	Equivalent to --with-target-bdw-gc-include=PATH/include
	plus --with-target-bdw-gc-lib=PATH/lib])])
	AC_ARG_WITH([target-bdw-gc-include],
	[AS_HELP_STRING([--with-target-bdw-gc-include=PATHLIST],
	[specify directories for installed bdw-gc include files])])
	AC_ARG_WITH([target-bdw-gc-lib],
	[AS_HELP_STRING([--with-target-bdw-gc-lib=PATHLIST],
	[specify directories for installed bdw-gc library])])

	case "$enable_objc_gc" in
	no)
	use_bdw_gc=no
	;;
	*)
	AC_MSG_CHECKING([for bdw garbage collector])
	if test "x$with_target_bdw_gc$with_target_bdw_gc_include$with_target_bdw_gc_lib" = x; then
	dnl no bdw-gw options, assuming bdw-gc in default locations
	BDW_GC_CFLAGS=
	BDW_GC_LIBS="-lgc"
	else
	dnl bdw-gw options passed by configure flags
	if test "x$with_target_bdw_gc_include" = x && test "x$with_target_bdw_gc_lib" != x; then
	AC_MSG_ERROR([found --with-target-bdw-gc-lib but --with-target-bdw-gc-include missing])
	elif test "x$with_target_bdw_gc_include" != x && test "x$with_target_bdw_gc_lib" = x; then
	AC_MSG_ERROR([found --with-target-bdw-gc-include but --with-target-bdw-gc-lib missing])
	else
	AC_MSG_RESULT([using paths configured with --with-target-bdw-gc options])
	fi
	mldir=`${CC-gcc} --print-multi-directory 2>/dev/null`
	bdw_val=
	if test "x$with_target_bdw_gc" != x; then
	for i in `echo $with_target_bdw_gc \| tr ',' ' '`; do
	case "$i" in
	=) sd=${i%%=}; d=${i#=} ;;
	*) sd=.; d=$i ;;
	esac
	if test "$mldir" = "$sd"; then
	bdw_val=$d
	fi
	done
	if test "x$bdw_val" = x; then
	AC_MSG_ERROR([no multilib path ($mldir) found in --with-target-bdw-gc])
	fi
	bdw_inc_dir="$bdw_val/include"
	bdw_lib_dir="$bdw_val/lib"
	fi
	bdw_val=
	if test "x$with_target_bdw_gc_include" != x; then
	for i in `echo $with_target_bdw_gc_include \| tr ',' ' '`; do
	case "$i" in
	=) sd=${i%%=}; d=${i#=} ;;
	*) sd=.; d=$i; fallback=$i ;;
	esac
	if test "$mldir" = "$sd"; then
	bdw_val=$d
	fi
	done
	if test "x$bdw_val" = x && test "x$bdw_inc_dir" = x && test "x$fallback" != x; then
	bdw_inc_dir="$fallback"
	elif test "x$bdw_val" = x; then
	AC_MSG_ERROR([no multilib path ($mldir) found in --with-target-bdw-gc-include])
	else
	bdw_inc_dir="$bdw_val"
	fi
	fi
	bdw_val=
	if test "x$with_target_bdw_gc_lib" != x; then
	for i in `echo $with_target_bdw_gc_lib \| tr ',' ' '`; do
	case "$i" in
	=) sd=${i%%=}; d=${i#=} ;;
	*) sd=.; d=$i ;;
	esac
	if test "$mldir" = "$sd"; then
	bdw_val=$d
	fi
	done
	if test "x$bdw_val" = x; then
	AC_MSG_ERROR([no multilib path ($mldir) found in --with-target-bdw-gc-lib])
	fi
	bdw_lib_dir="$bdw_val"
	fi
	if test "x$bdw_inc_dir" = x; then
	AC_MSG_ERROR([no multilib path ($mldir) found in --with-target-bdw-gc-include])
	fi
	if test "x$bdw_lib_dir" = x; then
	AC_MSG_ERROR([no multilib path ($mldir) found in --with-target-bdw-gc-lib])
	fi
	BDW_GC_CFLAGS="-I$bdw_inc_dir"
	if test -f $bdw_lib_dir/libgc.la; then
	BDW_GC_LIBS="$bdw_lib_dir/libgc.la"
	else
	BDW_GC_LIBS="-L$bdw_lib_dir -lgc"
	fi
	AC_MSG_RESULT([found])
	fi

	case "$BDW_GC_LIBS" in
	*libgc.la)
	use_bdw_gc=yes
	;;
	*)
	AC_MSG_CHECKING([for system boehm-gc])
	save_CFLAGS=$CFLAGS
	save_LIBS=$LIBS
	CFLAGS="$CFLAGS $BDW_GC_CFLAGS"
	LIBS="$LIBS $BDW_GC_LIBS"
	dnl the link test is not good enough for ARM32 multilib detection,
	dnl first check to link, then to run
	AC_LINK_IFELSE(
	[AC_LANG_PROGRAM([#include <gc/gc.h>],[GC_init()])],
	[
	AC_RUN_IFELSE([AC_LANG_SOURCE([[
	#include <gc/gc.h>
	int main() {
	GC_init();
	return 0;
	}
	]])],
	[system_bdw_gc_found=yes],
	[system_bdw_gc_found=no],
	dnl assume no system boehm-gc for cross builds ...
	[system_bdw_gc_found=no]
	)
	],
	[system_bdw_gc_found=no])
	CFLAGS=$save_CFLAGS
	LIBS=$save_LIBS
	if test x$enable_objc_gc = xauto && test x$system_bdw_gc_found = xno; then
	AC_MSG_WARN([system bdw-gc not found, not building libobjc_gc])
	use_bdw_gc=no
	elif test x$enable_objc_gc = xyes && test x$system_bdw_gc_found = xno; then
	AC_MSG_ERROR([system bdw-gc required but not found])
	else
	use_bdw_gc=yes
	AC_MSG_RESULT([found])
	fi
	esac
	esac

	if test "$use_bdw_gc" = no; then
	OBJC_GCFLAGS=''
	OBJC_BOEHM_GC=''
	OBJC_BOEHM_GC_INCLUDES=''
	OBJC_BOEHM_GC_LIBS=''
	else
	OBJC_GCFLAGS='-DOBJC_WITH_GC=1'
	OBJC_BOEHM_GC='libobjc_gc$(libsuffix).la'
	OBJC_BOEHM_GC_INCLUDES=$BDW_GC_CFLAGS
	OBJC_BOEHM_GC_LIBS=$BDW_GC_LIBS
	fi
	AC_SUBST(OBJC_GCFLAGS)
	AC_SUBST(OBJC_BOEHM_GC)
	AC_SUBST(OBJC_BOEHM_GC_INCLUDES)
	AC_SUBST(OBJC_BOEHM_GC_LIBS)

	# Determine what GCC version number to use in filesystem paths.
	GCC_BASE_VER

	# ------
	# Output
	# ------

	if test ${multilib} = yes; then
	multilib_arg="--enable-multilib"
	else
	multilib_arg=
	fi

	AC_CONFIG_FILES([Makefile])
	AC_OUTPUT