build: Update Guile's and Gettext's Autoconf macros.

* m4/guile.m4, m4/lib-link.m4, m4/lib-ld.m4, m4/lib-prefix.m4: Update
from Guile 2.0.12 and Gettext 0.19.8.
* build-aux/compile, build-aux/config.rpath: New files, imported from
Gettext.
* Makefile.am (EXTRA_DIST): Add them.
* INSTALL: Update.

Signed-off-by: Artyom V. Poptsov <poptsov.artyom@gmail.com>

8 files changed, 1563 insertions, 48 deletions

diff --git a/INSTALL b/INSTALL
index 007e939..2099840 100644
--- a/INSTALL
+++ b/INSTALL
@@ -12,8 +12,8 @@ without warranty of any kind.
 Basic Installation
 ==================
 
-   Briefly, the shell commands `./configure; make; make install' should
-configure, build, and install this package.  The following
+   Briefly, the shell command `./configure && make && make install'
+should configure, build, and install this package.  The following
 more-detailed instructions are generic; see the `README' file for
 instructions specific to this package.  Some packages provide this
 `INSTALL' file but do not implement all of the features documented
diff --git a/Makefile.am b/Makefile.am
index 42a9496..474c86f 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -21,8 +21,10 @@ ACLOCAL_AMFLAGS = -I m4 --install
 
 SUBDIRS = am libguile-ssh examples build-aux m4 doc modules tests
 
-EXTRA_DIST = \
-	.dir-locals.el			\
+EXTRA_DIST =					\
+	build-aux/config.rpath			\
+	build-aux/compile			\
+	.dir-locals.el				\
 	TODO
 
 gen-ChangeLog:
diff --git a/build-aux/compile b/build-aux/compile
new file mode 100755
index 0000000..4be2a80
--- /dev/null
+++ b/build-aux/compile
@@ -0,0 +1,347 @@
+#!/bin/sh
+# Wrapper for compilers which do not understand '-c -o'.
+
+scriptversion=2012-10-14.11; # UTC
+
+# Copyright (C) 1999-2014 Free Software Foundation, Inc.
+# Written by Tom Tromey <tromey@cygnus.com>.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# As a special exception to the GNU General Public License, if you
+# distribute this file as part of a program that contains a
+# configuration script generated by Autoconf, you may include it under
+# the same distribution terms that you use for the rest of that program.
+
+# This file is maintained in Automake, please report
+# bugs to <bug-automake@gnu.org> or send patches to
+# <automake-patches@gnu.org>.
+
+nl='
+'
+
+# We need space, tab and new line, in precisely that order.  Quoting is
+# there to prevent tools from complaining about whitespace usage.
+IFS=" ""	$nl"
+
+file_conv=
+
+# func_file_conv build_file lazy
+# Convert a $build file to $host form and store it in $file
+# Currently only supports Windows hosts. If the determined conversion
+# type is listed in (the comma separated) LAZY, no conversion will
+# take place.
+func_file_conv ()
+{
+  file=$1
+  case $file in
+    / | /[!/]*) # absolute file, and not a UNC file
+      if test -z "$file_conv"; then
+	# lazily determine how to convert abs files
+	case `uname -s` in
+	  MINGW*)
+	    file_conv=mingw
+	    ;;
+	  CYGWIN*)
+	    file_conv=cygwin
+	    ;;
+	  *)
+	    file_conv=wine
+	    ;;
+	esac
+      fi
+      case $file_conv/,$2, in
+	*,$file_conv,*)
+	  ;;
+	mingw/*)
+	  file=`cmd //C echo "$file " | sed -e 's/"\(.*\) " *$/\1/'`
+	  ;;
+	cygwin/*)
+	  file=`cygpath -m "$file" || echo "$file"`
+	  ;;
+	wine/*)
+	  file=`winepath -w "$file" || echo "$file"`
+	  ;;
+      esac
+      ;;
+  esac
+}
+
+# func_cl_dashL linkdir
+# Make cl look for libraries in LINKDIR
+func_cl_dashL ()
+{
+  func_file_conv "$1"
+  if test -z "$lib_path"; then
+    lib_path=$file
+  else
+    lib_path="$lib_path;$file"
+  fi
+  linker_opts="$linker_opts -LIBPATH:$file"
+}
+
+# func_cl_dashl library
+# Do a library search-path lookup for cl
+func_cl_dashl ()
+{
+  lib=$1
+  found=no
+  save_IFS=$IFS
+  IFS=';'
+  for dir in $lib_path $LIB
+  do
+    IFS=$save_IFS
+    if $shared && test -f "$dir/$lib.dll.lib"; then
+      found=yes
+      lib=$dir/$lib.dll.lib
+      break
+    fi
+    if test -f "$dir/$lib.lib"; then
+      found=yes
+      lib=$dir/$lib.lib
+      break
+    fi
+    if test -f "$dir/lib$lib.a"; then
+      found=yes
+      lib=$dir/lib$lib.a
+      break
+    fi
+  done
+  IFS=$save_IFS
+
+  if test "$found" != yes; then
+    lib=$lib.lib
+  fi
+}
+
+# func_cl_wrapper cl arg...
+# Adjust compile command to suit cl
+func_cl_wrapper ()
+{
+  # Assume a capable shell
+  lib_path=
+  shared=:
+  linker_opts=
+  for arg
+  do
+    if test -n "$eat"; then
+      eat=
+    else
+      case $1 in
+	-o)
+	  # configure might choose to run compile as 'compile cc -o foo foo.c'.
+	  eat=1
+	  case $2 in
+	    *.o | *.[oO][bB][jJ])
+	      func_file_conv "$2"
+	      set x "$@" -Fo"$file"
+	      shift
+	      ;;
+	    *)
+	      func_file_conv "$2"
+	      set x "$@" -Fe"$file"
+	      shift
+	      ;;
+	  esac
+	  ;;
+	-I)
+	  eat=1
+	  func_file_conv "$2" mingw
+	  set x "$@" -I"$file"
+	  shift
+	  ;;
+	-I*)
+	  func_file_conv "${1#-I}" mingw
+	  set x "$@" -I"$file"
+	  shift
+	  ;;
+	-l)
+	  eat=1
+	  func_cl_dashl "$2"
+	  set x "$@" "$lib"
+	  shift
+	  ;;
+	-l*)
+	  func_cl_dashl "${1#-l}"
+	  set x "$@" "$lib"
+	  shift
+	  ;;
+	-L)
+	  eat=1
+	  func_cl_dashL "$2"
+	  ;;
+	-L*)
+	  func_cl_dashL "${1#-L}"
+	  ;;
+	-static)
+	  shared=false
+	  ;;
+	-Wl,*)
+	  arg=${1#-Wl,}
+	  save_ifs="$IFS"; IFS=','
+	  for flag in $arg; do
+	    IFS="$save_ifs"
+	    linker_opts="$linker_opts $flag"
+	  done
+	  IFS="$save_ifs"
+	  ;;
+	-Xlinker)
+	  eat=1
+	  linker_opts="$linker_opts $2"
+	  ;;
+	-*)
+	  set x "$@" "$1"
+	  shift
+	  ;;
+	*.cc | *.CC | *.cxx | *.CXX | *.[cC]++)
+	  func_file_conv "$1"
+	  set x "$@" -Tp"$file"
+	  shift
+	  ;;
+	*.c | *.cpp | *.CPP | *.lib | *.LIB | *.Lib | *.OBJ | *.obj | *.[oO])
+	  func_file_conv "$1" mingw
+	  set x "$@" "$file"
+	  shift
+	  ;;
+	*)
+	  set x "$@" "$1"
+	  shift
+	  ;;
+      esac
+    fi
+    shift
+  done
+  if test -n "$linker_opts"; then
+    linker_opts="-link$linker_opts"
+  fi
+  exec "$@" $linker_opts
+  exit 1
+}
+
+eat=
+
+case $1 in
+  '')
+     echo "$0: No command.  Try '$0 --help' for more information." 1>&2
+     exit 1;
+     ;;
+  -h | --h*)
+    cat <<\EOF
+Usage: compile [--help] [--version] PROGRAM [ARGS]
+
+Wrapper for compilers which do not understand '-c -o'.
+Remove '-o dest.o' from ARGS, run PROGRAM with the remaining
+arguments, and rename the output as expected.
+
+If you are trying to build a whole package this is not the
+right script to run: please start by reading the file 'INSTALL'.
+
+Report bugs to <bug-automake@gnu.org>.
+EOF
+    exit $?
+    ;;
+  -v | --v*)
+    echo "compile $scriptversion"
+    exit $?
+    ;;
+  cl | *[/\\]cl | cl.exe | *[/\\]cl.exe )
+    func_cl_wrapper "$@"      # Doesn't return...
+    ;;
+esac
+
+ofile=
+cfile=
+
+for arg
+do
+  if test -n "$eat"; then
+    eat=
+  else
+    case $1 in
+      -o)
+	# configure might choose to run compile as 'compile cc -o foo foo.c'.
+	# So we strip '-o arg' only if arg is an object.
+	eat=1
+	case $2 in
+	  *.o | *.obj)
+	    ofile=$2
+	    ;;
+	  *)
+	    set x "$@" -o "$2"
+	    shift
+	    ;;
+	esac
+	;;
+      *.c)
+	cfile=$1
+	set x "$@" "$1"
+	shift
+	;;
+      *)
+	set x "$@" "$1"
+	shift
+	;;
+    esac
+  fi
+  shift
+done
+
+if test -z "$ofile" || test -z "$cfile"; then
+  # If no '-o' option was seen then we might have been invoked from a
+  # pattern rule where we don't need one.  That is ok -- this is a
+  # normal compilation that the losing compiler can handle.  If no
+  # '.c' file was seen then we are probably linking.  That is also
+  # ok.
+  exec "$@"
+fi
+
+# Name of file we expect compiler to create.
+cofile=`echo "$cfile" | sed 's|^.*[\\/]||; s|^[a-zA-Z]:||; s/\.c$/.o/'`
+
+# Create the lock directory.
+# Note: use '[/\\:.-]' here to ensure that we don't use the same name
+# that we are using for the .o file.  Also, base the name on the expected
+# object file name, since that is what matters with a parallel build.
+lockdir=`echo "$cofile" | sed -e 's|[/\\:.-]|_|g'`.d
+while true; do
+  if mkdir "$lockdir" >/dev/null 2>&1; then
+    break
+  fi
+  sleep 1
+done
+# FIXME: race condition here if user kills between mkdir and trap.
+trap "rmdir '$lockdir'; exit 1" 1 2 15
+
+# Run the compile.
+"$@"
+ret=$?
+
+if test -f "$cofile"; then
+  test "$cofile" = "$ofile" || mv "$cofile" "$ofile"
+elif test -f "${cofile}bj"; then
+  test "${cofile}bj" = "$ofile" || mv "${cofile}bj" "$ofile"
+fi
+
+rmdir "$lockdir"
+exit $ret
+
+# Local Variables:
+# mode: shell-script
+# sh-indentation: 2
+# eval: (add-hook 'write-file-hooks 'time-stamp)
+# time-stamp-start: "scriptversion="
+# time-stamp-format: "%:y-%02m-%02d.%02H"
+# time-stamp-time-zone: "UTC"
+# time-stamp-end: "; # UTC"
+# End:
diff --git a/build-aux/config.rpath b/build-aux/config.rpath
new file mode 100755
index 0000000..7a4952e
--- /dev/null
+++ b/build-aux/config.rpath
@@ -0,0 +1,684 @@
+#!/gnu/store/ykzwykkvr2c80rw4l1qh3mvfdkl7jibi-bash-4.3.42/bin/sh
+# Output a system dependent set of variables, describing how to set the
+# run time search path of shared libraries in an executable.
+#
+#   Copyright 1996-2016 Free Software Foundation, Inc.
+#   Taken from GNU libtool, 2001
+#   Originally by Gordon Matzigkeit <gord@gnu.ai.mit.edu>, 1996
+#
+#   This file is free software; the Free Software Foundation gives
+#   unlimited permission to copy and/or distribute it, with or without
+#   modifications, as long as this notice is preserved.
+#
+# The first argument passed to this file is the canonical host specification,
+#    CPU_TYPE-MANUFACTURER-OPERATING_SYSTEM
+# or
+#    CPU_TYPE-MANUFACTURER-KERNEL-OPERATING_SYSTEM
+# The environment variables CC, GCC, LDFLAGS, LD, with_gnu_ld
+# should be set by the caller.
+#
+# The set of defined variables is at the end of this script.
+
+# Known limitations:
+# - On IRIX 6.5 with CC="cc", the run time search patch must not be longer
+#   than 256 bytes, otherwise the compiler driver will dump core. The only
+#   known workaround is to choose shorter directory names for the build
+#   directory and/or the installation directory.
+
+# All known linkers require a '.a' archive for static linking (except MSVC,
+# which needs '.lib').
+libext=a
+shrext=.so
+
+host="$1"
+host_cpu=`echo "$host" | sed 's/^\([^-]*\)-\([^-]*\)-\(.*\)$/\1/'`
+host_vendor=`echo "$host" | sed 's/^\([^-]*\)-\([^-]*\)-\(.*\)$/\2/'`
+host_os=`echo "$host" | sed 's/^\([^-]*\)-\([^-]*\)-\(.*\)$/\3/'`
+
+# Code taken from libtool.m4's _LT_CC_BASENAME.
+
+for cc_temp in $CC""; do
+  case $cc_temp in
+    compile | *[\\/]compile | ccache | *[\\/]ccache ) ;;
+    distcc | *[\\/]distcc | purify | *[\\/]purify ) ;;
+    \-*) ;;
+    *) break;;
+  esac
+done
+cc_basename=`echo "$cc_temp" | sed -e 's%^.*/%%'`
+
+# Code taken from libtool.m4's _LT_COMPILER_PIC.
+
+wl=
+if test "$GCC" = yes; then
+  wl='-Wl,'
+else
+  case "$host_os" in
+    aix*)
+      wl='-Wl,'
+      ;;
+    mingw* | cygwin* | pw32* | os2* | cegcc*)
+      ;;
+    hpux9* | hpux10* | hpux11*)
+      wl='-Wl,'
+      ;;
+    irix5* | irix6* | nonstopux*)
+      wl='-Wl,'
+      ;;
+    linux* | k*bsd*-gnu | kopensolaris*-gnu)
+      case $cc_basename in
+        ecc*)
+          wl='-Wl,'
+          ;;
+        icc* | ifort*)
+          wl='-Wl,'
+          ;;
+        lf95*)
+          wl='-Wl,'
+          ;;
+        nagfor*)
+          wl='-Wl,-Wl,,'
+          ;;
+        pgcc* | pgf77* | pgf90* | pgf95* | pgfortran*)
+          wl='-Wl,'
+          ;;
+        ccc*)
+          wl='-Wl,'
+          ;;
+        xl* | bgxl* | bgf* | mpixl*)
+          wl='-Wl,'
+          ;;
+        como)
+          wl='-lopt='
+          ;;
+        *)
+          case `$CC -V 2>&1 | sed 5q` in
+            *Sun\ F* | *Sun*Fortran*)
+              wl=
+              ;;
+            *Sun\ C*)
+              wl='-Wl,'
+              ;;
+          esac
+          ;;
+      esac
+      ;;
+    newsos6)
+      ;;
+    *nto* | *qnx*)
+      ;;
+    osf3* | osf4* | osf5*)
+      wl='-Wl,'
+      ;;
+    rdos*)
+      ;;
+    solaris*)
+      case $cc_basename in
+        f77* | f90* | f95* | sunf77* | sunf90* | sunf95*)
+          wl='-Qoption ld '
+          ;;
+        *)
+          wl='-Wl,'
+          ;;
+      esac
+      ;;
+    sunos4*)
+      wl='-Qoption ld '
+      ;;
+    sysv4 | sysv4.2uw2* | sysv4.3*)
+      wl='-Wl,'
+      ;;
+    sysv4*MP*)
+      ;;
+    sysv5* | unixware* | sco3.2v5* | sco5v6* | OpenUNIX*)
+      wl='-Wl,'
+      ;;
+    unicos*)
+      wl='-Wl,'
+      ;;
+    uts4*)
+      ;;
+  esac
+fi
+
+# Code taken from libtool.m4's _LT_LINKER_SHLIBS.
+
+hardcode_libdir_flag_spec=
+hardcode_libdir_separator=
+hardcode_direct=no
+hardcode_minus_L=no
+
+case "$host_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
+    # Microsoft Visual C++.
+    if test "$GCC" != yes; then
+      with_gnu_ld=no
+    fi
+    ;;
+  interix*)
+    # we just hope/assume this is gcc and not c89 (= MSVC++)
+    with_gnu_ld=yes
+    ;;
+  openbsd*)
+    with_gnu_ld=no
+    ;;
+esac
+
+ld_shlibs=yes
+if test "$with_gnu_ld" = yes; then
+  # Set some defaults for GNU ld with shared library support. These
+  # are reset later if shared libraries are not supported. Putting them
+  # here allows them to be overridden if necessary.
+  # Unlike libtool, we use -rpath here, not --rpath, since the documented
+  # option of GNU ld is called -rpath, not --rpath.
+  hardcode_libdir_flag_spec='${wl}-rpath ${wl}$libdir'
+  case "$host_os" in
+    aix[3-9]*)
+      # On AIX/PPC, the GNU linker is very broken
+      if test "$host_cpu" != ia64; then
+        ld_shlibs=no
+      fi
+      ;;
+    amigaos*)
+      case "$host_cpu" in
+        powerpc)
+          ;;
+        m68k)
+          hardcode_libdir_flag_spec='-L$libdir'
+          hardcode_minus_L=yes
+          ;;
+      esac
+      ;;
+    beos*)
+      if $LD --help 2>&1 | grep ': supported targets:.* elf' > /dev/null; then
+        :
+      else
+        ld_shlibs=no
+      fi
+      ;;
+    cygwin* | mingw* | pw32* | cegcc*)
+      # hardcode_libdir_flag_spec is actually meaningless, as there is
+      # no search path for DLLs.
+      hardcode_libdir_flag_spec='-L$libdir'
+      if $LD --help 2>&1 | grep 'auto-import' > /dev/null; then
+        :
+      else
+        ld_shlibs=no
+      fi
+      ;;
+    haiku*)
+      ;;
+    interix[3-9]*)
+      hardcode_direct=no
+      hardcode_libdir_flag_spec='${wl}-rpath,$libdir'
+      ;;
+    gnu* | linux* | tpf* | k*bsd*-gnu | kopensolaris*-gnu)
+      if $LD --help 2>&1 | grep ': supported targets:.* elf' > /dev/null; then
+        :
+      else
+        ld_shlibs=no
+      fi
+      ;;
+    netbsd*)
+      ;;
+    solaris*)
+      if $LD -v 2>&1 | grep 'BFD 2\.8' > /dev/null; then
+        ld_shlibs=no
+      elif $LD --help 2>&1 | grep ': supported targets:.* elf' > /dev/null; then
+        :
+      else
+        ld_shlibs=no
+      fi
+      ;;
+    sysv5* | sco3.2v5* | sco5v6* | unixware* | OpenUNIX*)
+      case `$LD -v 2>&1` in
+        *\ [01].* | *\ 2.[0-9].* | *\ 2.1[0-5].*)
+          ld_shlibs=no
+          ;;
+        *)
+          if $LD --help 2>&1 | grep ': supported targets:.* elf' > /dev/null; then
+            hardcode_libdir_flag_spec='`test -z "$SCOABSPATH" && echo ${wl}-rpath,$libdir`'
+          else
+            ld_shlibs=no
+          fi
+          ;;
+      esac
+      ;;
+    sunos4*)
+      hardcode_direct=yes
+      ;;
+    *)
+      if $LD --help 2>&1 | grep ': supported targets:.* elf' > /dev/null; then
+        :
+      else
+        ld_shlibs=no
+      fi
+      ;;
+  esac
+  if test "$ld_shlibs" = no; then
+    hardcode_libdir_flag_spec=
+  fi
+else
+  case "$host_os" in
+    aix3*)
+      # Note: this linker hardcodes the directories in LIBPATH if there
+      # are no directories specified by -L.
+      hardcode_minus_L=yes
+      if test "$GCC" = yes; then
+        # Neither direct hardcoding nor static linking is supported with a
+        # broken collect2.
+        hardcode_direct=unsupported
+      fi
+      ;;
+    aix[4-9]*)
+      if test "$host_cpu" = ia64; then
+        # On IA64, the linker does run time linking by default, so we don't
+        # have to do anything special.
+        aix_use_runtimelinking=no
+      else
+        aix_use_runtimelinking=no
+        # Test if we are trying to use run time linking or normal
+        # AIX style linking. If -brtl is somewhere in LDFLAGS, we
+        # need to do runtime linking.
+        case $host_os in aix4.[23]|aix4.[23].*|aix[5-9]*)
+          for ld_flag in $LDFLAGS; do
+            if (test $ld_flag = "-brtl" || test $ld_flag = "-Wl,-brtl"); then
+              aix_use_runtimelinking=yes
+              break
+            fi
+          done
+          ;;
+        esac
+      fi
+      hardcode_direct=yes
+      hardcode_libdir_separator=':'
+      if test "$GCC" = yes; then
+        case $host_os in aix4.[012]|aix4.[012].*)
+          collect2name=`${CC} -print-prog-name=collect2`
+          if test -f "$collect2name" && \
+            strings "$collect2name" | grep resolve_lib_name >/dev/null
+          then
+            # We have reworked collect2
+            :
+          else
+            # We have old collect2
+            hardcode_direct=unsupported
+            hardcode_minus_L=yes
+            hardcode_libdir_flag_spec='-L$libdir'
+            hardcode_libdir_separator=
+          fi
+          ;;
+        esac
+      fi
+      # Begin _LT_AC_SYS_LIBPATH_AIX.
+      echo 'int main () { return 0; }' > conftest.c
+      ${CC} ${LDFLAGS} conftest.c -o conftest
+      aix_libpath=`dump -H conftest 2>/dev/null | sed -n -e '/Import File Strings/,/^$/ { /^0/ { s/^0  *\(.*\)$/\1/; p; }
+}'`
+      if test -z "$aix_libpath"; then
+        aix_libpath=`dump -HX64 conftest 2>/dev/null | sed -n -e '/Import File Strings/,/^$/ { /^0/ { s/^0  *\(.*\)$/\1/; p; }
+}'`
+      fi
+      if test -z "$aix_libpath"; then
+        aix_libpath="/usr/lib:/lib"
+      fi
+      rm -f conftest.c conftest
+      # End _LT_AC_SYS_LIBPATH_AIX.
+      if test "$aix_use_runtimelinking" = yes; then
+        hardcode_libdir_flag_spec='${wl}-blibpath:$libdir:'"$aix_libpath"
+      else
+        if test "$host_cpu" = ia64; then
+          hardcode_libdir_flag_spec='${wl}-R $libdir:/usr/lib:/lib'
+        else
+          hardcode_libdir_flag_spec='${wl}-blibpath:$libdir:'"$aix_libpath"
+        fi
+      fi
+      ;;
+    amigaos*)
+      case "$host_cpu" in
+        powerpc)
+          ;;
+        m68k)
+          hardcode_libdir_flag_spec='-L$libdir'
+          hardcode_minus_L=yes
+          ;;
+      esac
+      ;;
+    bsdi[45]*)
+      ;;
+    cygwin* | mingw* | pw32* | cegcc*)
+      # When not using gcc, we currently assume that we are using
+      # Microsoft Visual C++.
+      # hardcode_libdir_flag_spec is actually meaningless, as there is
+      # no search path for DLLs.
+      hardcode_libdir_flag_spec=' '
+      libext=lib
+      ;;
+    darwin* | rhapsody*)
+      hardcode_direct=no
+      if { case $cc_basename in ifort*) true;; *) test "$GCC" = yes;; esac; }; then
+        :
+      else
+        ld_shlibs=no
+      fi
+      ;;
+    dgux*)
+      hardcode_libdir_flag_spec='-L$libdir'
+      ;;
+    freebsd2.[01]*)
+      hardcode_direct=yes
+      hardcode_minus_L=yes
+      ;;
+    freebsd* | dragonfly*)
+      hardcode_libdir_flag_spec='-R$libdir'
+      hardcode_direct=yes
+      ;;
+    hpux9*)
+      hardcode_libdir_flag_spec='${wl}+b ${wl}$libdir'
+      hardcode_libdir_separator=:
+      hardcode_direct=yes
+      # hardcode_minus_L: Not really in the search PATH,
+      # but as the default location of the library.
+      hardcode_minus_L=yes
+      ;;
+    hpux10*)
+      if test "$with_gnu_ld" = no; then
+        hardcode_libdir_flag_spec='${wl}+b ${wl}$libdir'
+        hardcode_libdir_separator=:
+        hardcode_direct=yes
+        # hardcode_minus_L: Not really in the search PATH,
+        # but as the default location of the library.
+        hardcode_minus_L=yes
+      fi
+      ;;
+    hpux11*)
+      if test "$with_gnu_ld" = no; then
+        hardcode_libdir_flag_spec='${wl}+b ${wl}$libdir'
+        hardcode_libdir_separator=:
+        case $host_cpu in
+          hppa*64*|ia64*)
+            hardcode_direct=no
+            ;;
+          *)
+            hardcode_direct=yes
+            # hardcode_minus_L: Not really in the search PATH,
+            # but as the default location of the library.
+            hardcode_minus_L=yes
+            ;;
+        esac
+      fi
+      ;;
+    irix5* | irix6* | nonstopux*)
+      hardcode_libdir_flag_spec='${wl}-rpath ${wl}$libdir'
+      hardcode_libdir_separator=:
+      ;;
+    netbsd*)
+      hardcode_libdir_flag_spec='-R$libdir'
+      hardcode_direct=yes
+      ;;
+    newsos6)
+      hardcode_direct=yes
+      hardcode_libdir_flag_spec='${wl}-rpath ${wl}$libdir'
+      hardcode_libdir_separator=:
+      ;;
+    *nto* | *qnx*)
+      ;;
+    openbsd*)
+      if test -f /usr/libexec/ld.so; then
+        hardcode_direct=yes
+        if test -z "`echo __ELF__ | $CC -E - | grep __ELF__`" || test "$host_os-$host_cpu" = "openbsd2.8-powerpc"; then
+          hardcode_libdir_flag_spec='${wl}-rpath,$libdir'
+        else
+          case "$host_os" in
+            openbsd[01].* | openbsd2.[0-7] | openbsd2.[0-7].*)
+              hardcode_libdir_flag_spec='-R$libdir'
+              ;;
+            *)
+              hardcode_libdir_flag_spec='${wl}-rpath,$libdir'
+              ;;
+          esac
+        fi
+      else
+        ld_shlibs=no
+      fi
+      ;;
+    os2*)
+      hardcode_libdir_flag_spec='-L$libdir'
+      hardcode_minus_L=yes
+      ;;
+    osf3*)
+      hardcode_libdir_flag_spec='${wl}-rpath ${wl}$libdir'
+      hardcode_libdir_separator=:
+      ;;
+    osf4* | osf5*)
+      if test "$GCC" = yes; then
+        hardcode_libdir_flag_spec='${wl}-rpath ${wl}$libdir'
+      else
+        # Both cc and cxx compiler support -rpath directly
+        hardcode_libdir_flag_spec='-rpath $libdir'
+      fi
+      hardcode_libdir_separator=:
+      ;;
+    solaris*)
+      hardcode_libdir_flag_spec='-R$libdir'
+      ;;
+    sunos4*)
+      hardcode_libdir_flag_spec='-L$libdir'
+      hardcode_direct=yes
+      hardcode_minus_L=yes
+      ;;
+    sysv4)
+      case $host_vendor in
+        sni)
+          hardcode_direct=yes # is this really true???
+          ;;
+        siemens)
+          hardcode_direct=no
+          ;;
+        motorola)
+          hardcode_direct=no #Motorola manual says yes, but my tests say they lie
+          ;;
+      esac
+      ;;
+    sysv4.3*)
+      ;;
+    sysv4*MP*)
+      if test -d /usr/nec; then
+        ld_shlibs=yes
+      fi
+      ;;
+    sysv4*uw2* | sysv5OpenUNIX* | sysv5UnixWare7.[01].[10]* | unixware7* | sco3.2v5.0.[024]*)
+      ;;
+    sysv5* | sco3.2v5* | sco5v6*)
+      hardcode_libdir_flag_spec='`test -z "$SCOABSPATH" && echo ${wl}-R,$libdir`'
+      hardcode_libdir_separator=':'
+      ;;
+    uts4*)
+      hardcode_libdir_flag_spec='-L$libdir'
+      ;;
+    *)
+      ld_shlibs=no
+      ;;
+  esac
+fi
+
+# Check dynamic linker characteristics
+# Code taken from libtool.m4's _LT_SYS_DYNAMIC_LINKER.
+# Unlike libtool.m4, here we don't care about _all_ names of the library, but
+# only about the one the linker finds when passed -lNAME. This is the last
+# element of library_names_spec in libtool.m4, or possibly two of them if the
+# linker has special search rules.
+library_names_spec=      # the last element of library_names_spec in libtool.m4
+libname_spec='lib$name'
+case "$host_os" in
+  aix3*)
+    library_names_spec='$libname.a'
+    ;;
+  aix[4-9]*)
+    library_names_spec='$libname$shrext'
+    ;;
+  amigaos*)
+    case "$host_cpu" in
+      powerpc*)
+        library_names_spec='$libname$shrext' ;;
+      m68k)
+        library_names_spec='$libname.a' ;;
+    esac
+    ;;
+  beos*)
+    library_names_spec='$libname$shrext'
+    ;;
+  bsdi[45]*)
+    library_names_spec='$libname$shrext'
+    ;;
+  cygwin* | mingw* | pw32* | cegcc*)
+    shrext=.dll
+    library_names_spec='$libname.dll.a $libname.lib'
+    ;;
+  darwin* | rhapsody*)
+    shrext=.dylib
+    library_names_spec='$libname$shrext'
+    ;;
+  dgux*)
+    library_names_spec='$libname$shrext'
+    ;;
+  freebsd[23].*)
+    library_names_spec='$libname$shrext$versuffix'
+    ;;
+  freebsd* | dragonfly*)
+    library_names_spec='$libname$shrext'
+    ;;
+  gnu*)
+    library_names_spec='$libname$shrext'
+    ;;
+  haiku*)
+    library_names_spec='$libname$shrext'
+    ;;
+  hpux9* | hpux10* | hpux11*)
+    case $host_cpu in
+      ia64*)
+        shrext=.so
+        ;;
+      hppa*64*)
+        shrext=.sl
+        ;;
+      *)
+        shrext=.sl
+        ;;
+    esac
+    library_names_spec='$libname$shrext'
+    ;;
+  interix[3-9]*)
+    library_names_spec='$libname$shrext'
+    ;;
+  irix5* | irix6* | nonstopux*)
+    library_names_spec='$libname$shrext'
+    case "$host_os" in
+      irix5* | nonstopux*)
+        libsuff= shlibsuff=
+        ;;
+      *)
+        case $LD in
+          *-32|*"-32 "|*-melf32bsmip|*"-melf32bsmip ") libsuff= shlibsuff= ;;
+          *-n32|*"-n32 "|*-melf32bmipn32|*"-melf32bmipn32 ") libsuff=32 shlibsuff=N32 ;;
+          *-64|*"-64 "|*-melf64bmip|*"-melf64bmip ") libsuff=64 shlibsuff=64 ;;
+          *) libsuff= shlibsuff= ;;
+        esac
+        ;;
+    esac
+    ;;
+  linux*oldld* | linux*aout* | linux*coff*)
+    ;;
+  linux* | k*bsd*-gnu | kopensolaris*-gnu)
+    library_names_spec='$libname$shrext'
+    ;;
+  knetbsd*-gnu)
+    library_names_spec='$libname$shrext'
+    ;;
+  netbsd*)
+    library_names_spec='$libname$shrext'
+    ;;
+  newsos6)
+    library_names_spec='$libname$shrext'
+    ;;
+  *nto* | *qnx*)
+    library_names_spec='$libname$shrext'
+    ;;
+  openbsd*)
+    library_names_spec='$libname$shrext$versuffix'
+    ;;
+  os2*)
+    libname_spec='$name'
+    shrext=.dll
+    library_names_spec='$libname.a'
+    ;;
+  osf3* | osf4* | osf5*)
+    library_names_spec='$libname$shrext'
+    ;;
+  rdos*)
+    ;;
+  solaris*)
+    library_names_spec='$libname$shrext'
+    ;;
+  sunos4*)
+    library_names_spec='$libname$shrext$versuffix'
+    ;;
+  sysv4 | sysv4.3*)
+    library_names_spec='$libname$shrext'
+    ;;
+  sysv4*MP*)
+    library_names_spec='$libname$shrext'
+    ;;
+  sysv5* | sco3.2v5* | sco5v6* | unixware* | OpenUNIX* | sysv4*uw2*)
+    library_names_spec='$libname$shrext'
+    ;;
+  tpf*)
+    library_names_spec='$libname$shrext'
+    ;;
+  uts4*)
+    library_names_spec='$libname$shrext'
+    ;;
+esac
+
+sed_quote_subst='s/\(["`$\\]\)/\\\1/g'
+escaped_wl=`echo "X$wl" | sed -e 's/^X//' -e "$sed_quote_subst"`
+shlibext=`echo "$shrext" | sed -e 's,^\.,,'`
+escaped_libname_spec=`echo "X$libname_spec" | sed -e 's/^X//' -e "$sed_quote_subst"`
+escaped_library_names_spec=`echo "X$library_names_spec" | sed -e 's/^X//' -e "$sed_quote_subst"`
+escaped_hardcode_libdir_flag_spec=`echo "X$hardcode_libdir_flag_spec" | sed -e 's/^X//' -e "$sed_quote_subst"`
+
+LC_ALL=C sed -e 's/^\([a-zA-Z0-9_]*\)=/acl_cv_\1=/' <<EOF
+
+# How to pass a linker flag through the compiler.
+wl="$escaped_wl"
+
+# Static library suffix (normally "a").
+libext="$libext"
+
+# Shared library suffix (normally "so").
+shlibext="$shlibext"
+
+# Format of library name prefix.
+libname_spec="$escaped_libname_spec"
+
+# Library names that the linker finds when passed -lNAME.
+library_names_spec="$escaped_library_names_spec"
+
+# Flag to hardcode \$libdir into a binary during linking.
+# This must work even if \$libdir does not exist.
+hardcode_libdir_flag_spec="$escaped_hardcode_libdir_flag_spec"
+
+# Whether we need a single -rpath flag with a separated argument.
+hardcode_libdir_separator="$hardcode_libdir_separator"
+
+# Set to yes if using DIR/libNAME.so during linking hardcodes DIR into the
+# resulting binary.
+hardcode_direct="$hardcode_direct"
+
+# Set to yes if using the -LDIR flag during linking hardcodes DIR into the
+# resulting binary.
+hardcode_minus_L="$hardcode_minus_L"
+
+EOF
diff --git a/m4/guile.m4 b/m4/guile.m4
index 2f61c9b..441dcd4 100644
--- a/m4/guile.m4
+++ b/m4/guile.m4
@@ -1,17 +1,17 @@
 ## Autoconf macros for working with Guile.
 ##
-##   Copyright (C) 1998,2001, 2006. 2010 Free Software Foundation, Inc.
+##   Copyright (C) 1998,2001, 2006, 2010, 2012, 2013, 2014 Free Software Foundation, Inc.
 ##
 ## This library is free software; you can redistribute it and/or
 ## modify it under the terms of the GNU Lesser General Public License
 ## as published by the Free Software Foundation; either version 3 of
 ## the License, or (at your option) any later version.
-## 
+##
 ## This library 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
 ## Lesser General Public License for more details.
-## 
+##
 ## You should have received a copy of the GNU Lesser General Public
 ## License along with this library; if not, write to the Free Software
 ## Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
@@ -22,6 +22,7 @@
 ## Index
 ## -----
 ##
+## GUILE_PKG -- find Guile development files
 ## GUILE_PROGS -- set paths to Guile interpreter, config and tool programs
 ## GUILE_FLAGS -- set flags for compiling and linking with Guile
 ## GUILE_SITE_DIR -- find path to Guile "site" directory
@@ -38,61 +39,119 @@
 ## NOTE: Comments preceding an AC_DEFUN (starting from "Usage:") are massaged
 ## into doc/ref/autoconf-macros.texi (see Makefile.am in that directory).
 
-# GUILE_PROGS -- set paths to Guile interpreter, config and tool programs
+# GUILE_PKG -- find Guile development files
 #
-# Usage: GUILE_PROGS
+# Usage: GUILE_PKG([VERSIONS])
 #
-# This macro looks for programs @code{guile}, @code{guile-config} and
-# @code{guile-tools}, and sets variables @var{GUILE}, @var{GUILE_CONFIG} and
-# @var{GUILE_TOOLS}, to their paths, respectively.  If either of the first two
-# is not found, signal error.
+# This macro runs the @code{pkg-config} tool to find development files
+# for an available version of Guile.
 #
-# The variables are marked for substitution, as by @code{AC_SUBST}.
+# By default, this macro will search for the latest stable version of
+# Guile (e.g. 2.0), falling back to the previous stable version
+# (e.g. 1.8) if it is available.  If no guile-@var{VERSION}.pc file is
+# found, an error is signalled.  The found version is stored in
+# @var{GUILE_EFFECTIVE_VERSION}.
 #
-AC_DEFUN([GUILE_PROGS],
- [AC_PATH_PROG(GUILE,guile)
-  if test "$GUILE" = "" ; then
-      AC_MSG_ERROR([guile required but not found])
+# If @code{GUILE_PROGS} was already invoked, this macro ensures that the
+# development files have the same effective version as the Guile
+# program.
+#
+# @var{GUILE_EFFECTIVE_VERSION} is marked for substitution, as by
+# @code{AC_SUBST}.
+#
+AC_DEFUN([GUILE_PKG],
+ [PKG_PROG_PKG_CONFIG
+  _guile_versions_to_search="m4_default([$1], [2.0 1.8])"
+  if test -n "$GUILE_EFFECTIVE_VERSION"; then
+    _guile_tmp=""
+    for v in $_guile_versions_to_search; do
+      if test "$v" = "$GUILE_EFFECTIVE_VERSION"; then
+        _guile_tmp=$v
+      fi
+    done
+    if test -z "$_guile_tmp"; then
+      AC_MSG_FAILURE([searching for guile development files for versions $_guile_versions_to_search, but previously found $GUILE version $GUILE_EFFECTIVE_VERSION])
+    fi
+    _guile_versions_to_search=$GUILE_EFFECTIVE_VERSION
   fi
-  AC_SUBST(GUILE)
-  AC_PATH_PROG(GUILE_CONFIG,guile-config)
-  if test "$GUILE_CONFIG" = "" ; then
-      AC_MSG_ERROR([guile-config required but not found])
+  GUILE_EFFECTIVE_VERSION=""
+  _guile_errors=""
+  for v in $_guile_versions_to_search; do
+    if test -z "$GUILE_EFFECTIVE_VERSION"; then
+      AC_MSG_NOTICE([checking for guile $v])
+      PKG_CHECK_EXISTS([guile-$v], [GUILE_EFFECTIVE_VERSION=$v], [])
+    fi
+  done
+
+  if test -z "$GUILE_EFFECTIVE_VERSION"; then
+    AC_MSG_ERROR([
+No Guile development packages were found.
+
+Please verify that you have Guile installed.  If you installed Guile
+from a binary distribution, please verify that you have also installed
+the development packages.  If you installed it yourself, you might need
+to adjust your PKG_CONFIG_PATH; see the pkg-config man page for more.
+])
   fi
-  AC_SUBST(GUILE_CONFIG)
-  AC_PATH_PROG(GUILE_TOOLS,guile-tools)
-  AC_SUBST(GUILE_TOOLS)
+  AC_MSG_NOTICE([found guile $GUILE_EFFECTIVE_VERSION])
+  AC_SUBST([GUILE_EFFECTIVE_VERSION])
  ])
 
 # GUILE_FLAGS -- set flags for compiling and linking with Guile
 #
 # Usage: GUILE_FLAGS
 #
-# This macro runs the @code{guile-config} script, installed with Guile, to
-# find out where Guile's header files and libraries are installed.  It sets
-# two variables, @var{GUILE_CFLAGS} and @var{GUILE_LDFLAGS}.
+# This macro runs the @code{pkg-config} tool to find out how to compile
+# and link programs against Guile.  It sets four variables:
+# @var{GUILE_CFLAGS}, @var{GUILE_LDFLAGS}, @var{GUILE_LIBS}, and
+# @var{GUILE_LTLIBS}.
 #
 # @var{GUILE_CFLAGS}: flags to pass to a C or C++ compiler to build code that
-# uses Guile header files.  This is almost always just a @code{-I} flag.
+# uses Guile header files.  This is almost always just one or more @code{-I}
+# flags.
+#
+# @var{GUILE_LDFLAGS}: flags to pass to the compiler to link a program
+# against Guile.  This includes @code{-lguile-@var{VERSION}} for the
+# Guile library itself, and may also include one or more @code{-L} flag
+# to tell the compiler where to find the libraries.  But it does not
+# include flags that influence the program's runtime search path for
+# libraries, and will therefore lead to a program that fails to start,
+# unless all necessary libraries are installed in a standard location
+# such as @file{/usr/lib}.
 #
-# @var{GUILE_LDFLAGS}: flags to pass to the linker to link a program against
-# Guile.  This includes @code{-lguile} for the Guile library itself, any
-# libraries that Guile itself requires (like -lqthreads), and so on.  It may
-# also include a @code{-L} flag to tell the compiler where to find the
-# libraries.
+# @var{GUILE_LIBS} and @var{GUILE_LTLIBS}: flags to pass to the compiler or to
+# libtool, respectively, to link a program against Guile.  It includes flags
+# that augment the program's runtime search path for libraries, so that shared
+# libraries will be found at the location where they were during linking, even
+# in non-standard locations.  @var{GUILE_LIBS} is to be used when linking the
+# program directly with the compiler, whereas @var{GUILE_LTLIBS} is to be used
+# when linking the program is done through libtool.
 #
 # The variables are marked for substitution, as by @code{AC_SUBST}.
 #
 AC_DEFUN([GUILE_FLAGS],
- [AC_REQUIRE([GUILE_PROGS])dnl
-  AC_MSG_CHECKING([libguile compile flags])
-  GUILE_CFLAGS="`$GUILE_CONFIG compile`"
-  AC_MSG_RESULT([$GUILE_CFLAGS])
-  AC_MSG_CHECKING([libguile link flags])
-  GUILE_LDFLAGS="`$GUILE_CONFIG link`"
-  AC_MSG_RESULT([$GUILE_LDFLAGS])
-  AC_SUBST(GUILE_CFLAGS)
-  AC_SUBST(GUILE_LDFLAGS)
+ [AC_REQUIRE([GUILE_PKG])
+  PKG_CHECK_MODULES(GUILE, [guile-$GUILE_EFFECTIVE_VERSION])
+
+  dnl GUILE_CFLAGS and GUILE_LIBS are already defined and AC_SUBST'd by
+  dnl PKG_CHECK_MODULES.  But GUILE_LIBS to pkg-config is GUILE_LDFLAGS
+  dnl to us.
+
+  GUILE_LDFLAGS=$GUILE_LIBS
+
+  dnl Determine the platform dependent parameters needed to use rpath.
+  dnl AC_LIB_LINKFLAGS_FROM_LIBS is defined in gnulib/m4/lib-link.m4 and needs
+  dnl the file gnulib/build-aux/config.rpath.
+  AC_LIB_LINKFLAGS_FROM_LIBS([GUILE_LIBS], [$GUILE_LDFLAGS], [])
+  GUILE_LIBS="$GUILE_LDFLAGS $GUILE_LIBS"
+  AC_LIB_LINKFLAGS_FROM_LIBS([GUILE_LTLIBS], [$GUILE_LDFLAGS], [yes])
+  GUILE_LTLIBS="$GUILE_LDFLAGS $GUILE_LTLIBS"
+
+  AC_SUBST([GUILE_EFFECTIVE_VERSION])
+  AC_SUBST([GUILE_CFLAGS])
+  AC_SUBST([GUILE_LDFLAGS])
+  AC_SUBST([GUILE_LIBS])
+  AC_SUBST([GUILE_LTLIBS])
  ])
 
 # GUILE_SITE_DIR -- find path to Guile "site" directory
@@ -106,16 +165,96 @@ AC_DEFUN([GUILE_FLAGS],
 # The variable is marked for substitution, as by @code{AC_SUBST}.
 #
 AC_DEFUN([GUILE_SITE_DIR],
- [AC_REQUIRE([GUILE_PROGS])dnl
+ [AC_REQUIRE([GUILE_PKG])
   AC_MSG_CHECKING(for Guile site directory)
-  GUILE_SITE=`[$GUILE_CONFIG] info sitedir`
+  GUILE_SITE=`$PKG_CONFIG --print-errors --variable=sitedir guile-$GUILE_EFFECTIVE_VERSION`
+  AC_MSG_RESULT($GUILE_SITE)
   if test "$GUILE_SITE" = ""; then
-     GUILE_SITE=`[$GUILE_CONFIG] info pkgdatadir`/site
+     AC_MSG_FAILURE(sitedir not found)
   fi
-  AC_MSG_RESULT($GUILE_SITE)
   AC_SUBST(GUILE_SITE)
  ])
 
+# GUILE_PROGS -- set paths to Guile interpreter, config and tool programs
+#
+# Usage: GUILE_PROGS([VERSION])
+#
+# This macro looks for programs @code{guile} and @code{guild}, setting
+# variables @var{GUILE} and @var{GUILD} to their paths, respectively.
+# If @code{guile} is not found, signal an error.
+#
+# By default, this macro will search for the latest stable version of
+# Guile (e.g. 2.0). x.y or x.y.z versions can be specified. If an older
+# version is found, the macro will signal an error.
+#
+# The effective version of the found @code{guile} is set to
+# @var{GUILE_EFFECTIVE_VERSION}.  This macro ensures that the effective
+# version is compatible with the result of a previous invocation of
+# @code{GUILE_FLAGS}, if any.
+#
+# As a legacy interface, it also looks for @code{guile-config} and
+# @code{guile-tools}, setting @var{GUILE_CONFIG} and @var{GUILE_TOOLS}.
+#
+# The variables are marked for substitution, as by @code{AC_SUBST}.
+#
+AC_DEFUN([GUILE_PROGS],
+ [AC_PATH_PROG(GUILE,guile)
+  _guile_required_version="m4_default([$1], [$GUILE_EFFECTIVE_VERSION])"
+  if test -z "$_guile_required_version"; then
+    _guile_required_version=2.0
+  fi
+  if test "$GUILE" = "" ; then
+      AC_MSG_ERROR([guile required but not found])
+  fi
+  AC_SUBST(GUILE)
+
+  _guile_effective_version=`$GUILE -c "(display (effective-version))"`
+  if test -z "$GUILE_EFFECTIVE_VERSION"; then
+    GUILE_EFFECTIVE_VERSION=$_guile_effective_version
+  elif test "$GUILE_EFFECTIVE_VERSION" != "$_guile_effective_version"; then
+    AC_MSG_ERROR([found development files for Guile $GUILE_EFFECTIVE_VERSION, but $GUILE has effective version $_guile_effective_version])
+  fi
+
+  _guile_major_version=`$GUILE -c "(display (major-version))"`
+  _guile_minor_version=`$GUILE -c "(display (minor-version))"`
+  _guile_micro_version=`$GUILE -c "(display (micro-version))"`
+  _guile_prog_version="$_guile_major_version.$_guile_minor_version.$_guile_micro_version"
+
+  AC_MSG_CHECKING([for Guile version >= $_guile_required_version])
+  _major_version=`echo $_guile_required_version | cut -d . -f 1`
+  _minor_version=`echo $_guile_required_version | cut -d . -f 2`
+  _micro_version=`echo $_guile_required_version | cut -d . -f 3`
+  if test "$_guile_major_version" -ge "$_major_version"; then
+    if test "$_guile_minor_version" -ge "$_minor_version"; then
+      if test -n "$_micro_version"; then
+        if test "$_guile_micro_version" -lt "$_micro_version"; then
+          AC_MSG_ERROR([Guile $_guile_required_version required, but $_guile_prog_version found])
+        fi
+      fi
+    elif test "$GUILE_EFFECTIVE_VERSION" == "$_major_version.$_minor_version" -a -z "$_micro_version"; then
+      # Allow prereleases that have the right effective version.
+      true
+    else
+      as_fn_error $? "Guile $_guile_required_version required, but $_guile_prog_version found" "$LINENO" 5
+    fi
+  else
+    AC_MSG_ERROR([Guile $_guile_required_version required, but $_guile_prog_version found])
+  fi
+  AC_MSG_RESULT([$_guile_prog_version])
+
+  AC_PATH_PROG(GUILD,guild)
+  AC_SUBST(GUILD)
+
+  AC_PATH_PROG(GUILE_CONFIG,guile-config)
+  AC_SUBST(GUILE_CONFIG)
+  if test -n "$GUILD"; then
+    GUILE_TOOLS=$GUILD
+  else
+    AC_PATH_PROG(GUILE_TOOLS,guile-tools)
+  fi
+  AC_SUBST(GUILE_TOOLS)
+ ])
+
 # GUILE_CHECK -- evaluate Guile Scheme code and capture the return value
 #
 # Usage: GUILE_CHECK_RETVAL(var,check)
diff --git a/m4/lib-ld.m4 b/m4/lib-ld.m4
new file mode 100644
index 0000000..6209de6
--- /dev/null
+++ b/m4/lib-ld.m4
@@ -0,0 +1,119 @@
+# lib-ld.m4 serial 6
+dnl Copyright (C) 1996-2003, 2009-2016 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl Subroutines of libtool.m4,
+dnl with replacements s/_*LT_PATH/AC_LIB_PROG/ and s/lt_/acl_/ to avoid
+dnl collision with libtool.m4.
+
+dnl From libtool-2.4. Sets the variable with_gnu_ld to yes or no.
+AC_DEFUN([AC_LIB_PROG_LD_GNU],
+[AC_CACHE_CHECK([if the linker ($LD) is GNU ld], [acl_cv_prog_gnu_ld],
+[# I'd rather use --version here, but apparently some GNU lds only accept -v.
+case `$LD -v 2>&1 </dev/null` in
+*GNU* | *'with BFD'*)
+  acl_cv_prog_gnu_ld=yes
+  ;;
+*)
+  acl_cv_prog_gnu_ld=no
+  ;;
+esac])
+with_gnu_ld=$acl_cv_prog_gnu_ld
+])
+
+dnl From libtool-2.4. Sets the variable LD.
+AC_DEFUN([AC_LIB_PROG_LD],
+[AC_REQUIRE([AC_PROG_CC])dnl
+AC_REQUIRE([AC_CANONICAL_HOST])dnl
+
+AC_ARG_WITH([gnu-ld],
+    [AS_HELP_STRING([--with-gnu-ld],
+        [assume the C compiler uses GNU ld [default=no]])],
+    [test "$withval" = no || with_gnu_ld=yes],
+    [with_gnu_ld=no])dnl
+
+# Prepare PATH_SEPARATOR.
+# The user is always right.
+if test "${PATH_SEPARATOR+set}" != set; then
+  # Determine PATH_SEPARATOR by trying to find /bin/sh in a PATH which
+  # contains only /bin. Note that ksh looks also at the FPATH variable,
+  # so we have to set that as well for the test.
+  PATH_SEPARATOR=:
+  (PATH='/bin;/bin'; FPATH=$PATH; sh -c :) >/dev/null 2>&1 \
+    && { (PATH='/bin:/bin'; FPATH=$PATH; sh -c :) >/dev/null 2>&1 \
+           || PATH_SEPARATOR=';'
+       }
+fi
+
+ac_prog=ld
+if test "$GCC" = yes; then
+  # Check if gcc -print-prog-name=ld gives a path.
+  AC_MSG_CHECKING([for ld used by $CC])
+  case $host in
+  *-*-mingw*)
+    # gcc leaves a trailing carriage return which upsets mingw
+    ac_prog=`($CC -print-prog-name=ld) 2>&5 | tr -d '\015'` ;;
+  *)
+    ac_prog=`($CC -print-prog-name=ld) 2>&5` ;;
+  esac
+  case $ac_prog in
+    # Accept absolute paths.
+    [[\\/]]* | ?:[[\\/]]*)
+      re_direlt='/[[^/]][[^/]]*/\.\./'
+      # Canonicalize the pathname of ld
+      ac_prog=`echo "$ac_prog"| sed 's%\\\\%/%g'`
+      while echo "$ac_prog" | grep "$re_direlt" > /dev/null 2>&1; do
+        ac_prog=`echo $ac_prog| sed "s%$re_direlt%/%"`
+      done
+      test -z "$LD" && LD="$ac_prog"
+      ;;
+  "")
+    # If it fails, then pretend we aren't using GCC.
+    ac_prog=ld
+    ;;
+  *)
+    # If it is relative, then search for the first ld in PATH.
+    with_gnu_ld=unknown
+    ;;
+  esac
+elif test "$with_gnu_ld" = yes; then
+  AC_MSG_CHECKING([for GNU ld])
+else
+  AC_MSG_CHECKING([for non-GNU ld])
+fi
+AC_CACHE_VAL([acl_cv_path_LD],
+[if test -z "$LD"; then
+  acl_save_ifs="$IFS"; IFS=$PATH_SEPARATOR
+  for ac_dir in $PATH; do
+    IFS="$acl_save_ifs"
+    test -z "$ac_dir" && ac_dir=.
+    if test -f "$ac_dir/$ac_prog" || test -f "$ac_dir/$ac_prog$ac_exeext"; then
+      acl_cv_path_LD="$ac_dir/$ac_prog"
+      # Check to see if the program is GNU ld.  I'd rather use --version,
+      # but apparently some variants of GNU ld only accept -v.
+      # Break only if it was the GNU/non-GNU ld that we prefer.
+      case `"$acl_cv_path_LD" -v 2>&1 </dev/null` in
+      *GNU* | *'with BFD'*)
+        test "$with_gnu_ld" != no && break
+        ;;
+      *)
+        test "$with_gnu_ld" != yes && break
+        ;;
+      esac
+    fi
+  done
+  IFS="$acl_save_ifs"
+else
+  acl_cv_path_LD="$LD" # Let the user override the test with a path.
+fi])
+LD="$acl_cv_path_LD"
+if test -n "$LD"; then
+  AC_MSG_RESULT([$LD])
+else
+  AC_MSG_RESULT([no])
+fi
+test -z "$LD" && AC_MSG_ERROR([no acceptable ld found in \$PATH])
+AC_LIB_PROG_LD_GNU
+])
diff --git a/m4/lib-link.m4 b/m4/lib-link.m4
index 073f040..2f51855 100644
--- a/m4/lib-link.m4
+++ b/m4/lib-link.m4
@@ -1,5 +1,5 @@
 # lib-link.m4 serial 26 (gettext-0.18.2)
-dnl Copyright (C) 2001-2013 Free Software Foundation, Inc.
+dnl Copyright (C) 2001-2016 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
diff --git a/m4/lib-prefix.m4 b/m4/lib-prefix.m4
new file mode 100644
index 0000000..6851031
--- /dev/null
+++ b/m4/lib-prefix.m4
@@ -0,0 +1,224 @@
+# lib-prefix.m4 serial 7 (gettext-0.18)
+dnl Copyright (C) 2001-2005, 2008-2016 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Bruno Haible.
+
+dnl AC_LIB_ARG_WITH is synonymous to AC_ARG_WITH in autoconf-2.13, and
+dnl similar to AC_ARG_WITH in autoconf 2.52...2.57 except that is doesn't
+dnl require excessive bracketing.
+ifdef([AC_HELP_STRING],
+[AC_DEFUN([AC_LIB_ARG_WITH], [AC_ARG_WITH([$1],[[$2]],[$3],[$4])])],
+[AC_DEFUN([AC_][LIB_ARG_WITH], [AC_ARG_WITH([$1],[$2],[$3],[$4])])])
+
+dnl AC_LIB_PREFIX adds to the CPPFLAGS and LDFLAGS the flags that are needed
+dnl to access previously installed libraries. The basic assumption is that
+dnl a user will want packages to use other packages he previously installed
+dnl with the same --prefix option.
+dnl This macro is not needed if only AC_LIB_LINKFLAGS is used to locate
+dnl libraries, but is otherwise very convenient.
+AC_DEFUN([AC_LIB_PREFIX],
+[
+  AC_BEFORE([$0], [AC_LIB_LINKFLAGS])
+  AC_REQUIRE([AC_PROG_CC])
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  AC_REQUIRE([AC_LIB_PREPARE_MULTILIB])
+  AC_REQUIRE([AC_LIB_PREPARE_PREFIX])
+  dnl By default, look in $includedir and $libdir.
+  use_additional=yes
+  AC_LIB_WITH_FINAL_PREFIX([
+    eval additional_includedir=\"$includedir\"
+    eval additional_libdir=\"$libdir\"
+  ])
+  AC_LIB_ARG_WITH([lib-prefix],
+[  --with-lib-prefix[=DIR] search for libraries in DIR/include and DIR/lib
+  --without-lib-prefix    don't search for libraries in includedir and libdir],
+[
+    if test "X$withval" = "Xno"; then
+      use_additional=no
+    else
+      if test "X$withval" = "X"; then
+        AC_LIB_WITH_FINAL_PREFIX([
+          eval additional_includedir=\"$includedir\"
+          eval additional_libdir=\"$libdir\"
+        ])
+      else
+        additional_includedir="$withval/include"
+        additional_libdir="$withval/$acl_libdirstem"
+      fi
+    fi
+])
+  if test $use_additional = yes; then
+    dnl Potentially add $additional_includedir to $CPPFLAGS.
+    dnl But don't add it
+    dnl   1. if it's the standard /usr/include,
+    dnl   2. if it's already present in $CPPFLAGS,
+    dnl   3. if it's /usr/local/include and we are using GCC on Linux,
+    dnl   4. if it doesn't exist as a directory.
+    if test "X$additional_includedir" != "X/usr/include"; then
+      haveit=
+      for x in $CPPFLAGS; do
+        AC_LIB_WITH_FINAL_PREFIX([eval x=\"$x\"])
+        if test "X$x" = "X-I$additional_includedir"; then
+          haveit=yes
+          break
+        fi
+      done
+      if test -z "$haveit"; then
+        if test "X$additional_includedir" = "X/usr/local/include"; then
+          if test -n "$GCC"; then
+            case $host_os in
+              linux* | gnu* | k*bsd*-gnu) haveit=yes;;
+            esac
+          fi
+        fi
+        if test -z "$haveit"; then
+          if test -d "$additional_includedir"; then
+            dnl Really add $additional_includedir to $CPPFLAGS.
+            CPPFLAGS="${CPPFLAGS}${CPPFLAGS:+ }-I$additional_includedir"
+          fi
+        fi
+      fi
+    fi
+    dnl Potentially add $additional_libdir to $LDFLAGS.
+    dnl But don't add it
+    dnl   1. if it's the standard /usr/lib,
+    dnl   2. if it's already present in $LDFLAGS,
+    dnl   3. if it's /usr/local/lib and we are using GCC on Linux,
+    dnl   4. if it doesn't exist as a directory.
+    if test "X$additional_libdir" != "X/usr/$acl_libdirstem"; then
+      haveit=
+      for x in $LDFLAGS; do
+        AC_LIB_WITH_FINAL_PREFIX([eval x=\"$x\"])
+        if test "X$x" = "X-L$additional_libdir"; then
+          haveit=yes
+          break
+        fi
+      done
+      if test -z "$haveit"; then
+        if test "X$additional_libdir" = "X/usr/local/$acl_libdirstem"; then
+          if test -n "$GCC"; then
+            case $host_os in
+              linux*) haveit=yes;;
+            esac
+          fi
+        fi
+        if test -z "$haveit"; then
+          if test -d "$additional_libdir"; then
+            dnl Really add $additional_libdir to $LDFLAGS.
+            LDFLAGS="${LDFLAGS}${LDFLAGS:+ }-L$additional_libdir"
+          fi
+        fi
+      fi
+    fi
+  fi
+])
+
+dnl AC_LIB_PREPARE_PREFIX creates variables acl_final_prefix,
+dnl acl_final_exec_prefix, containing the values to which $prefix and
+dnl $exec_prefix will expand at the end of the configure script.
+AC_DEFUN([AC_LIB_PREPARE_PREFIX],
+[
+  dnl Unfortunately, prefix and exec_prefix get only finally determined
+  dnl at the end of configure.
+  if test "X$prefix" = "XNONE"; then
+    acl_final_prefix="$ac_default_prefix"
+  else
+    acl_final_prefix="$prefix"
+  fi
+  if test "X$exec_prefix" = "XNONE"; then
+    acl_final_exec_prefix='${prefix}'
+  else
+    acl_final_exec_prefix="$exec_prefix"
+  fi
+  acl_save_prefix="$prefix"
+  prefix="$acl_final_prefix"
+  eval acl_final_exec_prefix=\"$acl_final_exec_prefix\"
+  prefix="$acl_save_prefix"
+])
+
+dnl AC_LIB_WITH_FINAL_PREFIX([statement]) evaluates statement, with the
+dnl variables prefix and exec_prefix bound to the values they will have
+dnl at the end of the configure script.
+AC_DEFUN([AC_LIB_WITH_FINAL_PREFIX],
+[
+  acl_save_prefix="$prefix"
+  prefix="$acl_final_prefix"
+  acl_save_exec_prefix="$exec_prefix"
+  exec_prefix="$acl_final_exec_prefix"
+  $1
+  exec_prefix="$acl_save_exec_prefix"
+  prefix="$acl_save_prefix"
+])
+
+dnl AC_LIB_PREPARE_MULTILIB creates
+dnl - a variable acl_libdirstem, containing the basename of the libdir, either
+dnl   "lib" or "lib64" or "lib/64",
+dnl - a variable acl_libdirstem2, as a secondary possible value for
+dnl   acl_libdirstem, either the same as acl_libdirstem or "lib/sparcv9" or
+dnl   "lib/amd64".
+AC_DEFUN([AC_LIB_PREPARE_MULTILIB],
+[
+  dnl There is no formal standard regarding lib and lib64.
+  dnl On glibc systems, the current practice is that on a system supporting
+  dnl 32-bit and 64-bit instruction sets or ABIs, 64-bit libraries go under
+  dnl $prefix/lib64 and 32-bit libraries go under $prefix/lib. We determine
+  dnl the compiler's default mode by looking at the compiler's library search
+  dnl path. If at least one of its elements ends in /lib64 or points to a
+  dnl directory whose absolute pathname ends in /lib64, we assume a 64-bit ABI.
+  dnl Otherwise we use the default, namely "lib".
+  dnl On Solaris systems, the current practice is that on a system supporting
+  dnl 32-bit and 64-bit instruction sets or ABIs, 64-bit libraries go under
+  dnl $prefix/lib/64 (which is a symlink to either $prefix/lib/sparcv9 or
+  dnl $prefix/lib/amd64) and 32-bit libraries go under $prefix/lib.
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  acl_libdirstem=lib
+  acl_libdirstem2=
+  case "$host_os" in
+    solaris*)
+      dnl See Solaris 10 Software Developer Collection > Solaris 64-bit Developer's Guide > The Development Environment
+      dnl <http://docs.sun.com/app/docs/doc/816-5138/dev-env?l=en&a=view>.
+      dnl "Portable Makefiles should refer to any library directories using the 64 symbolic link."
+      dnl But we want to recognize the sparcv9 or amd64 subdirectory also if the
+      dnl symlink is missing, so we set acl_libdirstem2 too.
+      AC_CACHE_CHECK([for 64-bit host], [gl_cv_solaris_64bit],
+        [AC_EGREP_CPP([sixtyfour bits], [
+#ifdef _LP64
+sixtyfour bits
+#endif
+           ], [gl_cv_solaris_64bit=yes], [gl_cv_solaris_64bit=no])
+        ])
+      if test $gl_cv_solaris_64bit = yes; then
+        acl_libdirstem=lib/64
+        case "$host_cpu" in
+          sparc*)        acl_libdirstem2=lib/sparcv9 ;;
+          i*86 | x86_64) acl_libdirstem2=lib/amd64 ;;
+        esac
+      fi
+      ;;
+    *)
+      searchpath=`(LC_ALL=C $CC -print-search-dirs) 2>/dev/null | sed -n -e 's,^libraries: ,,p' | sed -e 's,^=,,'`
+      if test -n "$searchpath"; then
+        acl_save_IFS="${IFS= 	}"; IFS=":"
+        for searchdir in $searchpath; do
+          if test -d "$searchdir"; then
+            case "$searchdir" in
+              */lib64/ | */lib64 ) acl_libdirstem=lib64 ;;
+              */../ | */.. )
+                # Better ignore directories of this form. They are misleading.
+                ;;
+              *) searchdir=`cd "$searchdir" && pwd`
+                 case "$searchdir" in
+                   */lib64 ) acl_libdirstem=lib64 ;;
+                 esac ;;
+            esac
+          fi
+        done
+        IFS="$acl_save_IFS"
+      fi
+      ;;
+  esac
+  test -n "$acl_libdirstem2" || acl_libdirstem2="$acl_libdirstem"
+])