Imported Upstream version 1.1

5 files changed, 702 insertions, 461 deletions

diff --git a/build-aux/ar-lib b/build-aux/ar-lib
new file mode 100755
index 0000000..fe2301e
--- /dev/null
+++ b/build-aux/ar-lib
@@ -0,0 +1,270 @@
+#! /bin/sh
+# Wrapper for Microsoft lib.exe
+
+me=ar-lib
+scriptversion=2012-03-01.08; # UTC
+
+# Copyright (C) 2010-2013 Free Software Foundation, Inc.
+# Written by Peter Rosin <peda@lysator.liu.se>.
+#
+# 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>.
+
+
+# func_error message
+func_error ()
+{
+  echo "$me: $1" 1>&2
+  exit 1
+}
+
+file_conv=
+
+# func_file_conv build_file
+# Convert a $build file to $host form and store it in $file
+# Currently only supports Windows hosts.
+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 $file_conv in
+	mingw)
+	  file=`cmd //C echo "$file " | sed -e 's/"\(.*\) " *$/\1/'`
+	  ;;
+	cygwin)
+	  file=`cygpath -m "$file" || echo "$file"`
+	  ;;
+	wine)
+	  file=`winepath -w "$file" || echo "$file"`
+	  ;;
+      esac
+      ;;
+  esac
+}
+
+# func_at_file at_file operation archive
+# Iterate over all members in AT_FILE performing OPERATION on ARCHIVE
+# for each of them.
+# When interpreting the content of the @FILE, do NOT use func_file_conv,
+# since the user would need to supply preconverted file names to
+# binutils ar, at least for MinGW.
+func_at_file ()
+{
+  operation=$2
+  archive=$3
+  at_file_contents=`cat "$1"`
+  eval set x "$at_file_contents"
+  shift
+
+  for member
+  do
+    $AR -NOLOGO $operation:"$member" "$archive" || exit $?
+  done
+}
+
+case $1 in
+  '')
+     func_error "no command.  Try '$0 --help' for more information."
+     ;;
+  -h | --h*)
+    cat <<EOF
+Usage: $me [--help] [--version] PROGRAM ACTION ARCHIVE [MEMBER...]
+
+Members may be specified in a file named with @FILE.
+EOF
+    exit $?
+    ;;
+  -v | --v*)
+    echo "$me, version $scriptversion"
+    exit $?
+    ;;
+esac
+
+if test $# -lt 3; then
+  func_error "you must specify a program, an action and an archive"
+fi
+
+AR=$1
+shift
+while :
+do
+  if test $# -lt 2; then
+    func_error "you must specify a program, an action and an archive"
+  fi
+  case $1 in
+    -lib | -LIB \
+    | -ltcg | -LTCG \
+    | -machine* | -MACHINE* \
+    | -subsystem* | -SUBSYSTEM* \
+    | -verbose | -VERBOSE \
+    | -wx* | -WX* )
+      AR="$AR $1"
+      shift
+      ;;
+    *)
+      action=$1
+      shift
+      break
+      ;;
+  esac
+done
+orig_archive=$1
+shift
+func_file_conv "$orig_archive"
+archive=$file
+
+# strip leading dash in $action
+action=${action#-}
+
+delete=
+extract=
+list=
+quick=
+replace=
+index=
+create=
+
+while test -n "$action"
+do
+  case $action in
+    d*) delete=yes  ;;
+    x*) extract=yes ;;
+    t*) list=yes    ;;
+    q*) quick=yes   ;;
+    r*) replace=yes ;;
+    s*) index=yes   ;;
+    S*)             ;; # the index is always updated implicitly
+    c*) create=yes  ;;
+    u*)             ;; # TODO: don't ignore the update modifier
+    v*)             ;; # TODO: don't ignore the verbose modifier
+    *)
+      func_error "unknown action specified"
+      ;;
+  esac
+  action=${action#?}
+done
+
+case $delete$extract$list$quick$replace,$index in
+  yes,* | ,yes)
+    ;;
+  yesyes*)
+    func_error "more than one action specified"
+    ;;
+  *)
+    func_error "no action specified"
+    ;;
+esac
+
+if test -n "$delete"; then
+  if test ! -f "$orig_archive"; then
+    func_error "archive not found"
+  fi
+  for member
+  do
+    case $1 in
+      @*)
+        func_at_file "${1#@}" -REMOVE "$archive"
+        ;;
+      *)
+        func_file_conv "$1"
+        $AR -NOLOGO -REMOVE:"$file" "$archive" || exit $?
+        ;;
+    esac
+  done
+
+elif test -n "$extract"; then
+  if test ! -f "$orig_archive"; then
+    func_error "archive not found"
+  fi
+  if test $# -gt 0; then
+    for member
+    do
+      case $1 in
+        @*)
+          func_at_file "${1#@}" -EXTRACT "$archive"
+          ;;
+        *)
+          func_file_conv "$1"
+          $AR -NOLOGO -EXTRACT:"$file" "$archive" || exit $?
+          ;;
+      esac
+    done
+  else
+    $AR -NOLOGO -LIST "$archive" | sed -e 's/\\/\\\\/g' | while read member
+    do
+      $AR -NOLOGO -EXTRACT:"$member" "$archive" || exit $?
+    done
+  fi
+
+elif test -n "$quick$replace"; then
+  if test ! -f "$orig_archive"; then
+    if test -z "$create"; then
+      echo "$me: creating $orig_archive"
+    fi
+    orig_archive=
+  else
+    orig_archive=$archive
+  fi
+
+  for member
+  do
+    case $1 in
+    @*)
+      func_file_conv "${1#@}"
+      set x "$@" "@$file"
+      ;;
+    *)
+      func_file_conv "$1"
+      set x "$@" "$file"
+      ;;
+    esac
+    shift
+    shift
+  done
+
+  if test -n "$orig_archive"; then
+    $AR -NOLOGO -OUT:"$archive" "$orig_archive" "$@" || exit $?
+  else
+    $AR -NOLOGO -OUT:"$archive" "$@" || exit $?
+  fi
+
+elif test -n "$list"; then
+  if test ! -f "$orig_archive"; then
+    func_error "archive not found"
+  fi
+  $AR -NOLOGO -LIST "$archive" || exit $?
+fi
diff --git a/build-aux/compile b/build-aux/compile
index 862a14e..531136b 100755
--- a/build-aux/compile
+++ b/build-aux/compile
@@ -1,10 +1,9 @@
 #! /bin/sh
 # Wrapper for compilers which do not understand '-c -o'.
 
-scriptversion=2012-03-05.13; # UTC
+scriptversion=2012-10-14.11; # UTC
 
-# Copyright (C) 1999, 2000, 2003, 2004, 2005, 2009, 2010, 2012 Free
-# Software Foundation, Inc.
+# Copyright (C) 1999-2013 Free Software Foundation, Inc.
 # Written by Tom Tromey <tromey@cygnus.com>.
 #
 # This program is free software; you can redistribute it and/or modify
@@ -113,6 +112,11 @@ func_cl_dashl ()
       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
 
diff --git a/build-aux/depcomp b/build-aux/depcomp
index 25a39e6..4ebd5b3 100755
--- a/build-aux/depcomp
+++ b/build-aux/depcomp
@@ -1,10 +1,9 @@
 #! /bin/sh
 # depcomp - compile a program generating dependencies as side-effects
 
-scriptversion=2012-03-27.16; # UTC
+scriptversion=2013-05-30.07; # UTC
 
-# Copyright (C) 1999, 2000, 2003, 2004, 2005, 2006, 2007, 2009, 2010,
-# 2011, 2012 Free Software Foundation, Inc.
+# Copyright (C) 1999-2013 Free Software Foundation, Inc.
 
 # 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
@@ -28,9 +27,9 @@ scriptversion=2012-03-27.16; # UTC
 
 case $1 in
   '')
-     echo "$0: No command.  Try '$0 --help' for more information." 1>&2
-     exit 1;
-     ;;
+    echo "$0: No command.  Try '$0 --help' for more information." 1>&2
+    exit 1;
+    ;;
   -h | --h*)
     cat <<\EOF
 Usage: depcomp [--help] [--version] PROGRAM [ARGS]
@@ -57,11 +56,65 @@ EOF
     ;;
 esac
 
+# Get the directory component of the given path, and save it in the
+# global variables '$dir'.  Note that this directory component will
+# be either empty or ending with a '/' character.  This is deliberate.
+set_dir_from ()
+{
+  case $1 in
+    */*) dir=`echo "$1" | sed -e 's|/[^/]*$|/|'`;;
+      *) dir=;;
+  esac
+}
+
+# Get the suffix-stripped basename of the given path, and save it the
+# global variable '$base'.
+set_base_from ()
+{
+  base=`echo "$1" | sed -e 's|^.*/||' -e 's/\.[^.]*$//'`
+}
+
+# If no dependency file was actually created by the compiler invocation,
+# we still have to create a dummy depfile, to avoid errors with the
+# Makefile "include basename.Plo" scheme.
+make_dummy_depfile ()
+{
+  echo "#dummy" > "$depfile"
+}
+
+# Factor out some common post-processing of the generated depfile.
+# Requires the auxiliary global variable '$tmpdepfile' to be set.
+aix_post_process_depfile ()
+{
+  # If the compiler actually managed to produce a dependency file,
+  # post-process it.
+  if test -f "$tmpdepfile"; then
+    # Each line is of the form 'foo.o: dependency.h'.
+    # Do two passes, one to just change these to
+    #   $object: dependency.h
+    # and one to simply output
+    #   dependency.h:
+    # which is needed to avoid the deleted-header problem.
+    { sed -e "s,^.*\.[$lower]*:,$object:," < "$tmpdepfile"
+      sed -e "s,^.*\.[$lower]*:[$tab ]*,," -e 's,$,:,' < "$tmpdepfile"
+    } > "$depfile"
+    rm -f "$tmpdepfile"
+  else
+    make_dummy_depfile
+  fi
+}
+
 # A tabulation character.
 tab='	'
 # A newline character.
 nl='
 '
+# Character ranges might be problematic outside the C locale.
+# These definitions help.
+upper=ABCDEFGHIJKLMNOPQRSTUVWXYZ
+lower=abcdefghijklmnopqrstuvwxyz
+digits=0123456789
+alpha=${upper}${lower}
 
 if test -z "$depmode" || test -z "$source" || test -z "$object"; then
   echo "depcomp: Variables source, object and depmode must be set" 1>&2
@@ -75,6 +128,9 @@ tmpdepfile=${tmpdepfile-`echo "$depfile" | sed 's/\.\([^.]*\)$/.T\1/'`}
 
 rm -f "$tmpdepfile"
 
+# Avoid interferences from the environment.
+gccflag= dashmflag=
+
 # Some modes work just like other modes, but use different flags.  We
 # parameterize here, but still list the modes in the big case below,
 # to make depend.m4 easier to write.  Note that we *cannot* use a case
@@ -86,32 +142,32 @@ if test "$depmode" = hp; then
 fi
 
 if test "$depmode" = dashXmstdout; then
-   # This is just like dashmstdout with a different argument.
-   dashmflag=-xM
-   depmode=dashmstdout
+  # This is just like dashmstdout with a different argument.
+  dashmflag=-xM
+  depmode=dashmstdout
 fi
 
 cygpath_u="cygpath -u -f -"
 if test "$depmode" = msvcmsys; then
-   # This is just like msvisualcpp but w/o cygpath translation.
-   # Just convert the backslash-escaped backslashes to single forward
-   # slashes to satisfy depend.m4
-   cygpath_u='sed s,\\\\,/,g'
-   depmode=msvisualcpp
+  # This is just like msvisualcpp but w/o cygpath translation.
+  # Just convert the backslash-escaped backslashes to single forward
+  # slashes to satisfy depend.m4
+  cygpath_u='sed s,\\\\,/,g'
+  depmode=msvisualcpp
 fi
 
 if test "$depmode" = msvc7msys; then
-   # This is just like msvc7 but w/o cygpath translation.
-   # Just convert the backslash-escaped backslashes to single forward
-   # slashes to satisfy depend.m4
-   cygpath_u='sed s,\\\\,/,g'
-   depmode=msvc7
+  # This is just like msvc7 but w/o cygpath translation.
+  # Just convert the backslash-escaped backslashes to single forward
+  # slashes to satisfy depend.m4
+  cygpath_u='sed s,\\\\,/,g'
+  depmode=msvc7
 fi
 
 if test "$depmode" = xlc; then
-   # IBM C/C++ Compilers xlc/xlC can output gcc-like dependency informations.
-   gccflag=-qmakedep=gcc,-MF
-   depmode=gcc
+  # IBM C/C++ Compilers xlc/xlC can output gcc-like dependency information.
+  gccflag=-qmakedep=gcc,-MF
+  depmode=gcc
 fi
 
 case "$depmode" in
@@ -134,8 +190,7 @@ gcc3)
   done
   "$@"
   stat=$?
-  if test $stat -eq 0; then :
-  else
+  if test $stat -ne 0; then
     rm -f "$tmpdepfile"
     exit $stat
   fi
@@ -143,13 +198,17 @@ gcc3)
   ;;
 
 gcc)
+## Note that this doesn't just cater to obsosete pre-3.x GCC compilers.
+## but also to in-use compilers like IMB xlc/xlC and the HP C compiler.
+## (see the conditional assignment to $gccflag above).
 ## There are various ways to get dependency output from gcc.  Here's
 ## why we pick this rather obscure method:
 ## - Don't want to use -MD because we'd like the dependencies to end
 ##   up in a subdir.  Having to rename by hand is ugly.
 ##   (We might end up doing this anyway to support other compilers.)
 ## - The DEPENDENCIES_OUTPUT environment variable makes gcc act like
-##   -MM, not -M (despite what the docs say).
+##   -MM, not -M (despite what the docs say).  Also, it might not be
+##   supported by the other compilers which use the 'gcc' depmode.
 ## - Using -M directly means running the compiler twice (even worse
 ##   than renaming).
   if test -z "$gccflag"; then
@@ -157,15 +216,14 @@ gcc)
   fi
   "$@" -Wp,"$gccflag$tmpdepfile"
   stat=$?
-  if test $stat -eq 0; then :
-  else
+  if test $stat -ne 0; then
     rm -f "$tmpdepfile"
     exit $stat
   fi
   rm -f "$depfile"
   echo "$object : \\" > "$depfile"
-  alpha=ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz
-## The second -e expression handles DOS-style file names with drive letters.
+  # The second -e expression handles DOS-style file names with drive
+  # letters.
   sed -e 's/^[^:]*: / /' \
       -e 's/^['$alpha']:\/[^:]*: / /' < "$tmpdepfile" >> "$depfile"
 ## This next piece of magic avoids the "deleted header file" problem.
@@ -174,15 +232,15 @@ gcc)
 ## typically no way to rebuild the header).  We avoid this by adding
 ## dummy dependencies for each header file.  Too bad gcc doesn't do
 ## this for us directly.
-  tr ' ' "$nl" < "$tmpdepfile" |
 ## Some versions of gcc put a space before the ':'.  On the theory
 ## that the space means something, we add a space to the output as
 ## well.  hp depmode also adds that space, but also prefixes the VPATH
 ## to the object.  Take care to not repeat it in the output.
 ## Some versions of the HPUX 10.20 sed can't process this invocation
 ## correctly.  Breaking it into two sed invocations is a workaround.
-    sed -e 's/^\\$//' -e '/^$/d' -e "s|.*$object$||" -e '/:$/d' \
-      | sed -e 's/$/ :/' >> "$depfile"
+  tr ' ' "$nl" < "$tmpdepfile" \
+    | sed -e 's/^\\$//' -e '/^$/d' -e "s|.*$object$||" -e '/:$/d' \
+    | sed -e 's/$/ :/' >> "$depfile"
   rm -f "$tmpdepfile"
   ;;
 
@@ -200,8 +258,7 @@ sgi)
     "$@" -MDupdate "$tmpdepfile"
   fi
   stat=$?
-  if test $stat -eq 0; then :
-  else
+  if test $stat -ne 0; then
     rm -f "$tmpdepfile"
     exit $stat
   fi
@@ -209,7 +266,6 @@ sgi)
 
   if test -f "$tmpdepfile"; then  # yes, the sourcefile depend on other files
     echo "$object : \\" > "$depfile"
-
     # Clip off the initial element (the dependent).  Don't try to be
     # clever and replace this with sed code, as IRIX sed won't handle
     # lines with more than a fixed number of characters (4096 in
@@ -217,19 +273,15 @@ sgi)
     # the IRIX cc adds comments like '#:fec' to the end of the
     # dependency line.
     tr ' ' "$nl" < "$tmpdepfile" \
-    | sed -e 's/^.*\.o://' -e 's/#.*$//' -e '/^$/ d' | \
-    tr "$nl" ' ' >> "$depfile"
+      | sed -e 's/^.*\.o://' -e 's/#.*$//' -e '/^$/ d' \
+      | tr "$nl" ' ' >> "$depfile"
     echo >> "$depfile"
-
     # The second pass generates a dummy entry for each header file.
     tr ' ' "$nl" < "$tmpdepfile" \
-   | sed -e 's/^.*\.o://' -e 's/#.*$//' -e '/^$/ d' -e 's/$/:/' \
-   >> "$depfile"
+      | sed -e 's/^.*\.o://' -e 's/#.*$//' -e '/^$/ d' -e 's/$/:/' \
+      >> "$depfile"
   else
-    # The sourcefile does not contain any dependencies, so just
-    # store a dummy comment line, to avoid errors with the Makefile
-    # "include basename.Plo" scheme.
-    echo "#dummy" > "$depfile"
+    make_dummy_depfile
   fi
   rm -f "$tmpdepfile"
   ;;
@@ -247,9 +299,8 @@ aix)
   # current directory.  Also, the AIX compiler puts '$object:' at the
   # start of each line; $object doesn't have directory information.
   # Version 6 uses the directory in both cases.
-  dir=`echo "$object" | sed -e 's|/[^/]*$|/|'`
-  test "x$dir" = "x$object" && dir=
-  base=`echo "$object" | sed -e 's|^.*/||' -e 's/\.o$//' -e 's/\.lo$//'`
+  set_dir_from "$object"
+  set_base_from "$object"
   if test "$libtool" = yes; then
     tmpdepfile1=$dir$base.u
     tmpdepfile2=$base.u
@@ -262,9 +313,7 @@ aix)
     "$@" -M
   fi
   stat=$?
-
-  if test $stat -eq 0; then :
-  else
+  if test $stat -ne 0; then
     rm -f "$tmpdepfile1" "$tmpdepfile2" "$tmpdepfile3"
     exit $stat
   fi
@@ -273,65 +322,113 @@ aix)
   do
     test -f "$tmpdepfile" && break
   done
-  if test -f "$tmpdepfile"; then
-    # Each line is of the form 'foo.o: dependent.h'.
-    # Do two passes, one to just change these to
-    # '$object: dependent.h' and one to simply 'dependent.h:'.
-    sed -e "s,^.*\.[a-z]*:,$object:," < "$tmpdepfile" > "$depfile"
-    sed -e 's,^.*\.[a-z]*:['"$tab"' ]*,,' -e 's,$,:,' < "$tmpdepfile" >> "$depfile"
-  else
-    # The sourcefile does not contain any dependencies, so just
-    # store a dummy comment line, to avoid errors with the Makefile
-    # "include basename.Plo" scheme.
-    echo "#dummy" > "$depfile"
+  aix_post_process_depfile
+  ;;
+
+tcc)
+  # tcc (Tiny C Compiler) understand '-MD -MF file' since version 0.9.26
+  # FIXME: That version still under development at the moment of writing.
+  #        Make that this statement remains true also for stable, released
+  #        versions.
+  # It will wrap lines (doesn't matter whether long or short) with a
+  # trailing '\', as in:
+  #
+  #   foo.o : \
+  #    foo.c \
+  #    foo.h \
+  #
+  # It will put a trailing '\' even on the last line, and will use leading
+  # spaces rather than leading tabs (at least since its commit 0394caf7
+  # "Emit spaces for -MD").
+  "$@" -MD -MF "$tmpdepfile"
+  stat=$?
+  if test $stat -ne 0; then
+    rm -f "$tmpdepfile"
+    exit $stat
   fi
+  rm -f "$depfile"
+  # Each non-empty line is of the form 'foo.o : \' or ' dep.h \'.
+  # We have to change lines of the first kind to '$object: \'.
+  sed -e "s|.*:|$object :|" < "$tmpdepfile" > "$depfile"
+  # And for each line of the second kind, we have to emit a 'dep.h:'
+  # dummy dependency, to avoid the deleted-header problem.
+  sed -n -e 's|^  *\(.*\) *\\$|\1:|p' < "$tmpdepfile" >> "$depfile"
   rm -f "$tmpdepfile"
   ;;
 
-icc)
-  # Intel's C compiler anf tcc (Tiny C Compiler) understand '-MD -MF file'.
-  # However on
-  #    $CC -MD -MF foo.d -c -o sub/foo.o sub/foo.c
-  # ICC 7.0 will fill foo.d with something like
-  #    foo.o: sub/foo.c
-  #    foo.o: sub/foo.h
-  # which is wrong.  We want
-  #    sub/foo.o: sub/foo.c
-  #    sub/foo.o: sub/foo.h
-  #    sub/foo.c:
-  #    sub/foo.h:
-  # ICC 7.1 will output
+## The order of this option in the case statement is important, since the
+## shell code in configure will try each of these formats in the order
+## listed in this file.  A plain '-MD' option would be understood by many
+## compilers, so we must ensure this comes after the gcc and icc options.
+pgcc)
+  # Portland's C compiler understands '-MD'.
+  # Will always output deps to 'file.d' where file is the root name of the
+  # source file under compilation, even if file resides in a subdirectory.
+  # The object file name does not affect the name of the '.d' file.
+  # pgcc 10.2 will output
   #    foo.o: sub/foo.c sub/foo.h
-  # and will wrap long lines using '\':
+  # and will wrap long lines using '\' :
   #    foo.o: sub/foo.c ... \
   #     sub/foo.h ... \
   #     ...
-  # tcc 0.9.26 (FIXME still under development at the moment of writing)
-  # will emit a similar output, but also prepend the continuation lines
-  # with horizontal tabulation characters.
-  "$@" -MD -MF "$tmpdepfile"
-  stat=$?
-  if test $stat -eq 0; then :
-  else
+  set_dir_from "$object"
+  # Use the source, not the object, to determine the base name, since
+  # that's sadly what pgcc will do too.
+  set_base_from "$source"
+  tmpdepfile=$base.d
+
+  # For projects that build the same source file twice into different object
+  # files, the pgcc approach of using the *source* file root name can cause
+  # problems in parallel builds.  Use a locking strategy to avoid stomping on
+  # the same $tmpdepfile.
+  lockdir=$base.d-lock
+  trap "
+    echo '$0: caught signal, cleaning up...' >&2
+    rmdir '$lockdir'
+    exit 1
+  " 1 2 13 15
+  numtries=100
+  i=$numtries
+  while test $i -gt 0; do
+    # mkdir is a portable test-and-set.
+    if mkdir "$lockdir" 2>/dev/null; then
+      # This process acquired the lock.
+      "$@" -MD
+      stat=$?
+      # Release the lock.
+      rmdir "$lockdir"
+      break
+    else
+      # If the lock is being held by a different process, wait
+      # until the winning process is done or we timeout.
+      while test -d "$lockdir" && test $i -gt 0; do
+        sleep 1
+        i=`expr $i - 1`
+      done
+    fi
+    i=`expr $i - 1`
+  done
+  trap - 1 2 13 15
+  if test $i -le 0; then
+    echo "$0: failed to acquire lock after $numtries attempts" >&2
+    echo "$0: check lockdir '$lockdir'" >&2
+    exit 1
+  fi
+
+  if test $stat -ne 0; then
     rm -f "$tmpdepfile"
     exit $stat
   fi
   rm -f "$depfile"
-  # Each line is of the form 'foo.o: dependent.h',
-  # or 'foo.o: dep1.h dep2.h \', or ' dep3.h dep4.h \'.
+  # Each line is of the form `foo.o: dependent.h',
+  # or `foo.o: dep1.h dep2.h \', or ` dep3.h dep4.h \'.
   # Do two passes, one to just change these to
-  # '$object: dependent.h' and one to simply 'dependent.h:'.
-  sed -e "s/^[ $tab][ $tab]*/  /" -e "s,^[^:]*:,$object :," \
-    < "$tmpdepfile" > "$depfile"
-  sed '
-    s/[ '"$tab"'][ '"$tab"']*/ /g
-    s/^ *//
-    s/ *\\*$//
-    s/^[^:]*: *//
-    /^$/d
-    /:$/d
-    s/$/ :/
-  ' < "$tmpdepfile" >> "$depfile"
+  # `$object: dependent.h' and one to simply `dependent.h:'.
+  sed "s,^[^:]*:,$object :," < "$tmpdepfile" > "$depfile"
+  # Some versions of the HPUX 10.20 sed can't process this invocation
+  # correctly.  Breaking it into two sed invocations is a workaround.
+  sed 's,^[^:]*: \(.*\)$,\1,;s/^\\$//;/^$/d;/:$/d' < "$tmpdepfile" \
+    | sed -e 's/$/ :/' >> "$depfile"
   rm -f "$tmpdepfile"
   ;;
 
@@ -342,9 +439,8 @@ hp2)
   # 'foo.d', which lands next to the object file, wherever that
   # happens to be.
   # Much of this is similar to the tru64 case; see comments there.
-  dir=`echo "$object" | sed -e 's|/[^/]*$|/|'`
-  test "x$dir" = "x$object" && dir=
-  base=`echo "$object" | sed -e 's|^.*/||' -e 's/\.o$//' -e 's/\.lo$//'`
+  set_dir_from  "$object"
+  set_base_from "$object"
   if test "$libtool" = yes; then
     tmpdepfile1=$dir$base.d
     tmpdepfile2=$dir.libs/$base.d
@@ -355,8 +451,7 @@ hp2)
     "$@" +Maked
   fi
   stat=$?
-  if test $stat -eq 0; then :
-  else
+  if test $stat -ne 0; then
      rm -f "$tmpdepfile1" "$tmpdepfile2"
      exit $stat
   fi
@@ -366,76 +461,61 @@ hp2)
     test -f "$tmpdepfile" && break
   done
   if test -f "$tmpdepfile"; then
-    sed -e "s,^.*\.[a-z]*:,$object:," "$tmpdepfile" > "$depfile"
+    sed -e "s,^.*\.[$lower]*:,$object:," "$tmpdepfile" > "$depfile"
     # Add 'dependent.h:' lines.
     sed -ne '2,${
-	       s/^ *//
-	       s/ \\*$//
-	       s/$/:/
-	       p
-	     }' "$tmpdepfile" >> "$depfile"
+               s/^ *//
+               s/ \\*$//
+               s/$/:/
+               p
+             }' "$tmpdepfile" >> "$depfile"
   else
-    echo "#dummy" > "$depfile"
+    make_dummy_depfile
   fi
   rm -f "$tmpdepfile" "$tmpdepfile2"
   ;;
 
 tru64)
-   # The Tru64 compiler uses -MD to generate dependencies as a side
-   # effect.  'cc -MD -o foo.o ...' puts the dependencies into 'foo.o.d'.
-   # At least on Alpha/Redhat 6.1, Compaq CCC V6.2-504 seems to put
-   # dependencies in 'foo.d' instead, so we check for that too.
-   # Subdirectories are respected.
-   dir=`echo "$object" | sed -e 's|/[^/]*$|/|'`
-   test "x$dir" = "x$object" && dir=
-   base=`echo "$object" | sed -e 's|^.*/||' -e 's/\.o$//' -e 's/\.lo$//'`
-
-   if test "$libtool" = yes; then
-      # With Tru64 cc, shared objects can also be used to make a
-      # static library.  This mechanism is used in libtool 1.4 series to
-      # handle both shared and static libraries in a single compilation.
-      # With libtool 1.4, dependencies were output in $dir.libs/$base.lo.d.
-      #
-      # With libtool 1.5 this exception was removed, and libtool now
-      # generates 2 separate objects for the 2 libraries.  These two
-      # compilations output dependencies in $dir.libs/$base.o.d and
-      # in $dir$base.o.d.  We have to check for both files, because
-      # one of the two compilations can be disabled.  We should prefer
-      # $dir$base.o.d over $dir.libs/$base.o.d because the latter is
-      # automatically cleaned when .libs/ is deleted, while ignoring
-      # the former would cause a distcleancheck panic.
-      tmpdepfile1=$dir.libs/$base.lo.d   # libtool 1.4
-      tmpdepfile2=$dir$base.o.d          # libtool 1.5
-      tmpdepfile3=$dir.libs/$base.o.d    # libtool 1.5
-      tmpdepfile4=$dir.libs/$base.d      # Compaq CCC V6.2-504
-      "$@" -Wc,-MD
-   else
-      tmpdepfile1=$dir$base.o.d
-      tmpdepfile2=$dir$base.d
-      tmpdepfile3=$dir$base.d
-      tmpdepfile4=$dir$base.d
-      "$@" -MD
-   fi
-
-   stat=$?
-   if test $stat -eq 0; then :
-   else
-      rm -f "$tmpdepfile1" "$tmpdepfile2" "$tmpdepfile3" "$tmpdepfile4"
-      exit $stat
-   fi
-
-   for tmpdepfile in "$tmpdepfile1" "$tmpdepfile2" "$tmpdepfile3" "$tmpdepfile4"
-   do
-     test -f "$tmpdepfile" && break
-   done
-   if test -f "$tmpdepfile"; then
-      sed -e "s,^.*\.[a-z]*:,$object:," < "$tmpdepfile" > "$depfile"
-      sed -e 's,^.*\.[a-z]*:['"$tab"' ]*,,' -e 's,$,:,' < "$tmpdepfile" >> "$depfile"
-   else
-      echo "#dummy" > "$depfile"
-   fi
-   rm -f "$tmpdepfile"
-   ;;
+  # The Tru64 compiler uses -MD to generate dependencies as a side
+  # effect.  'cc -MD -o foo.o ...' puts the dependencies into 'foo.o.d'.
+  # At least on Alpha/Redhat 6.1, Compaq CCC V6.2-504 seems to put
+  # dependencies in 'foo.d' instead, so we check for that too.
+  # Subdirectories are respected.
+  set_dir_from  "$object"
+  set_base_from "$object"
+
+  if test "$libtool" = yes; then
+    # Libtool generates 2 separate objects for the 2 libraries.  These
+    # two compilations output dependencies in $dir.libs/$base.o.d and
+    # in $dir$base.o.d.  We have to check for both files, because
+    # one of the two compilations can be disabled.  We should prefer
+    # $dir$base.o.d over $dir.libs/$base.o.d because the latter is
+    # automatically cleaned when .libs/ is deleted, while ignoring
+    # the former would cause a distcleancheck panic.
+    tmpdepfile1=$dir$base.o.d          # libtool 1.5
+    tmpdepfile2=$dir.libs/$base.o.d    # Likewise.
+    tmpdepfile3=$dir.libs/$base.d      # Compaq CCC V6.2-504
+    "$@" -Wc,-MD
+  else
+    tmpdepfile1=$dir$base.d
+    tmpdepfile2=$dir$base.d
+    tmpdepfile3=$dir$base.d
+    "$@" -MD
+  fi
+
+  stat=$?
+  if test $stat -ne 0; then
+    rm -f "$tmpdepfile1" "$tmpdepfile2" "$tmpdepfile3"
+    exit $stat
+  fi
+
+  for tmpdepfile in "$tmpdepfile1" "$tmpdepfile2" "$tmpdepfile3"
+  do
+    test -f "$tmpdepfile" && break
+  done
+  # Same post-processing that is required for AIX mode.
+  aix_post_process_depfile
+  ;;
 
 msvc7)
   if test "$libtool" = yes; then
@@ -446,8 +526,7 @@ msvc7)
   "$@" $showIncludes > "$tmpdepfile"
   stat=$?
   grep -v '^Note: including file: ' "$tmpdepfile"
-  if test "$stat" = 0; then :
-  else
+  if test $stat -ne 0; then
     rm -f "$tmpdepfile"
     exit $stat
   fi
@@ -473,6 +552,7 @@ $ {
   G
   p
 }' >> "$depfile"
+  echo >> "$depfile" # make sure the fragment doesn't end with a backslash
   rm -f "$tmpdepfile"
   ;;
 
@@ -524,13 +604,14 @@ dashmstdout)
   # in the target name.  This is to cope with DOS-style filenames:
   # a dependency such as 'c:/foo/bar' could be seen as target 'c' otherwise.
   "$@" $dashmflag |
-    sed 's:^['"$tab"' ]*[^:'"$tab"' ][^:][^:]*\:['"$tab"' ]*:'"$object"'\: :' > "$tmpdepfile"
+    sed "s|^[$tab ]*[^:$tab ][^:][^:]*:[$tab ]*|$object: |" > "$tmpdepfile"
   rm -f "$depfile"
   cat < "$tmpdepfile" > "$depfile"
-  tr ' ' "$nl" < "$tmpdepfile" | \
-## Some versions of the HPUX 10.20 sed can't process this invocation
-## correctly.  Breaking it into two sed invocations is a workaround.
-    sed -e 's/^\\$//' -e '/^$/d' -e '/:$/d' | sed -e 's/$/ :/' >> "$depfile"
+  # Some versions of the HPUX 10.20 sed can't process this sed invocation
+  # correctly.  Breaking it into two sed invocations is a workaround.
+  tr ' ' "$nl" < "$tmpdepfile" \
+    | sed -e 's/^\\$//' -e '/^$/d' -e '/:$/d' \
+    | sed -e 's/$/ :/' >> "$depfile"
   rm -f "$tmpdepfile"
   ;;
 
@@ -583,10 +664,12 @@ makedepend)
   # makedepend may prepend the VPATH from the source file name to the object.
   # No need to regex-escape $object, excess matching of '.' is harmless.
   sed "s|^.*\($object *:\)|\1|" "$tmpdepfile" > "$depfile"
-  sed '1,2d' "$tmpdepfile" | tr ' ' "$nl" | \
-## Some versions of the HPUX 10.20 sed can't process this invocation
-## correctly.  Breaking it into two sed invocations is a workaround.
-    sed -e 's/^\\$//' -e '/^$/d' -e '/:$/d' | sed -e 's/$/ :/' >> "$depfile"
+  # Some versions of the HPUX 10.20 sed can't process the last invocation
+  # correctly.  Breaking it into two sed invocations is a workaround.
+  sed '1,2d' "$tmpdepfile" \
+    | tr ' ' "$nl" \
+    | sed -e 's/^\\$//' -e '/^$/d' -e '/:$/d' \
+    | sed -e 's/$/ :/' >> "$depfile"
   rm -f "$tmpdepfile" "$tmpdepfile".bak
   ;;
 
@@ -622,10 +705,10 @@ cpp)
     esac
   done
 
-  "$@" -E |
-    sed -n -e '/^# [0-9][0-9]* "\([^"]*\)".*/ s:: \1 \\:p' \
-       -e '/^#line [0-9][0-9]* "\([^"]*\)".*/ s:: \1 \\:p' |
-    sed '$ s: \\$::' > "$tmpdepfile"
+  "$@" -E \
+    | sed -n -e '/^# [0-9][0-9]* "\([^"]*\)".*/ s:: \1 \\:p' \
+             -e '/^#line [0-9][0-9]* "\([^"]*\)".*/ s:: \1 \\:p' \
+    | sed '$ s: \\$::' > "$tmpdepfile"
   rm -f "$depfile"
   echo "$object : \\" > "$depfile"
   cat < "$tmpdepfile" >> "$depfile"
@@ -657,15 +740,15 @@ msvisualcpp)
       shift
       ;;
     "-Gm"|"/Gm"|"-Gi"|"/Gi"|"-ZI"|"/ZI")
-	set fnord "$@"
-	shift
-	shift
-	;;
+        set fnord "$@"
+        shift
+        shift
+        ;;
     *)
-	set fnord "$@" "$arg"
-	shift
-	shift
-	;;
+        set fnord "$@" "$arg"
+        shift
+        shift
+        ;;
     esac
   done
   "$@" -E 2>/dev/null |
diff --git a/build-aux/install-sh b/build-aux/install-sh
index a9244eb..377bb86 100755
--- a/build-aux/install-sh
+++ b/build-aux/install-sh
@@ -1,7 +1,7 @@
 #!/bin/sh
 # install - install a program, script, or datafile
 
-scriptversion=2011-01-19.21; # UTC
+scriptversion=2011-11-20.07; # UTC
 
 # This originates from X11R5 (mit/util/scripts/install.sh), which was
 # later released in X11R6 (xc/config/util/install.sh) with the
@@ -35,7 +35,7 @@ scriptversion=2011-01-19.21; # UTC
 # FSF changes to this file are in the public domain.
 #
 # Calling this script install-sh is preferred over install.sh, to prevent
-# `make' implicit rules from creating a file called install from it
+# 'make' implicit rules from creating a file called install from it
 # when there is no Makefile.
 #
 # This script is compatible with the BSD install script, but was written
@@ -156,7 +156,7 @@ while test $# -ne 0; do
     -s) stripcmd=$stripprog;;
 
     -t) dst_arg=$2
-	# Protect names problematic for `test' and other utilities.
+	# Protect names problematic for 'test' and other utilities.
 	case $dst_arg in
 	  -* | [=\(\)!]) dst_arg=./$dst_arg;;
 	esac
@@ -190,7 +190,7 @@ if test $# -ne 0 && test -z "$dir_arg$dst_arg"; then
     fi
     shift # arg
     dst_arg=$arg
-    # Protect names problematic for `test' and other utilities.
+    # Protect names problematic for 'test' and other utilities.
     case $dst_arg in
       -* | [=\(\)!]) dst_arg=./$dst_arg;;
     esac
@@ -202,7 +202,7 @@ if test $# -eq 0; then
     echo "$0: no input file specified." >&2
     exit 1
   fi
-  # It's OK to call `install-sh -d' without argument.
+  # It's OK to call 'install-sh -d' without argument.
   # This can happen when creating conditional directories.
   exit 0
 fi
@@ -240,7 +240,7 @@ fi
 
 for src
 do
-  # Protect names problematic for `test' and other utilities.
+  # Protect names problematic for 'test' and other utilities.
   case $src in
     -* | [=\(\)!]) src=./$src;;
   esac
@@ -354,7 +354,7 @@ do
 	      if test -z "$dir_arg" || {
 		   # Check for POSIX incompatibilities with -m.
 		   # HP-UX 11.23 and IRIX 6.5 mkdir -m -p sets group- or
-		   # other-writeable bit of parent directory when it shouldn't.
+		   # other-writable bit of parent directory when it shouldn't.
 		   # FreeBSD 6.1 mkdir -m -p sets mode of existing directory.
 		   ls_ld_tmpdir=`ls -ld "$tmpdir"`
 		   case $ls_ld_tmpdir in
diff --git a/build-aux/missing b/build-aux/missing
index 86a8fc3..db98974 100755
--- a/build-aux/missing
+++ b/build-aux/missing
@@ -1,11 +1,10 @@
 #! /bin/sh
-# Common stub for a few missing GNU programs while installing.
+# Common wrapper for a few potentially missing GNU programs.
 
-scriptversion=2012-01-06.13; # UTC
+scriptversion=2013-10-28.13; # UTC
 
-# Copyright (C) 1996, 1997, 1999, 2000, 2002, 2003, 2004, 2005, 2006,
-# 2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
-# Originally by Fran,cois Pinard <pinard@iro.umontreal.ca>, 1996.
+# Copyright (C) 1996-2013 Free Software Foundation, Inc.
+# Originally written by Fran,cois Pinard <pinard@iro.umontreal.ca>, 1996.
 
 # 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
@@ -26,68 +25,40 @@ scriptversion=2012-01-06.13; # UTC
 # the same distribution terms that you use for the rest of that program.
 
 if test $# -eq 0; then
-  echo 1>&2 "Try \`$0 --help' for more information"
+  echo 1>&2 "Try '$0 --help' for more information"
   exit 1
 fi
 
-run=:
-sed_output='s/.* --output[ =]\([^ ]*\).*/\1/p'
-sed_minuso='s/.* -o \([^ ]*\).*/\1/p'
-
-# In the cases where this matters, `missing' is being run in the
-# srcdir already.
-if test -f configure.ac; then
-  configure_ac=configure.ac
-else
-  configure_ac=configure.in
-fi
+case $1 in
 
-msg="missing on your system"
+  --is-lightweight)
+    # Used by our autoconf macros to check whether the available missing
+    # script is modern enough.
+    exit 0
+    ;;
 
-case $1 in
---run)
-  # Try to run requested program, and just exit if it succeeds.
-  run=
-  shift
-  "$@" && exit 0
-  # Exit code 63 means version mismatch.  This often happens
-  # when the user try to use an ancient version of a tool on
-  # a file that requires a minimum version.  In this case we
-  # we should proceed has if the program had been absent, or
-  # if --run hadn't been passed.
-  if test $? = 63; then
-    run=:
-    msg="probably too old"
-  fi
-  ;;
+  --run)
+    # Back-compat with the calling convention used by older automake.
+    shift
+    ;;
 
   -h|--h|--he|--hel|--help)
     echo "\
 $0 [OPTION]... PROGRAM [ARGUMENT]...
 
-Handle \`PROGRAM [ARGUMENT]...' for when PROGRAM is missing, or return an
-error status if there is no known handling for PROGRAM.
+Run 'PROGRAM [ARGUMENT]...', returning a proper advice when this fails due
+to PROGRAM being missing or too old.
 
 Options:
   -h, --help      display this help and exit
   -v, --version   output version information and exit
-  --run           try to run the given command, and emulate it if it fails
 
 Supported PROGRAM values:
-  aclocal      touch file \`aclocal.m4'
-  autoconf     touch file \`configure'
-  autoheader   touch file \`config.h.in'
-  autom4te     touch the output file, or create a stub one
-  automake     touch all \`Makefile.in' files
-  bison        create \`y.tab.[ch]', if possible, from existing .[ch]
-  flex         create \`lex.yy.c', if possible, from existing .c
-  help2man     touch the output file
-  lex          create \`lex.yy.c', if possible, from existing .c
-  makeinfo     touch the output file
-  yacc         create \`y.tab.[ch]', if possible, from existing .[ch]
+  aclocal   autoconf  autoheader   autom4te  automake  makeinfo
+  bison     yacc      flex         lex       help2man
 
-Version suffixes to PROGRAM as well as the prefixes \`gnu-', \`gnu', and
-\`g' are ignored when checking the name.
+Version suffixes to PROGRAM as well as the prefixes 'gnu-', 'gnu', and
+'g' are ignored when checking the name.
 
 Send bug reports to <bug-automake@gnu.org>."
     exit $?
@@ -99,228 +70,141 @@ Send bug reports to <bug-automake@gnu.org>."
     ;;
 
   -*)
-    echo 1>&2 "$0: Unknown \`$1' option"
-    echo 1>&2 "Try \`$0 --help' for more information"
+    echo 1>&2 "$0: unknown '$1' option"
+    echo 1>&2 "Try '$0 --help' for more information"
     exit 1
     ;;
 
 esac
 
-# normalize program name to check for.
-program=`echo "$1" | sed '
-  s/^gnu-//; t
-  s/^gnu//; t
-  s/^g//; t'`
-
-# Now exit if we have it, but it failed.  Also exit now if we
-# don't have it and --version was passed (most likely to detect
-# the program).  This is about non-GNU programs, so use $1 not
-# $program.
-case $1 in
-  lex*|yacc*)
-    # Not GNU programs, they don't have --version.
-    ;;
-
-  *)
-    if test -z "$run" && ($1 --version) > /dev/null 2>&1; then
-       # We have it, but it failed.
-       exit 1
-    elif test "x$2" = "x--version" || test "x$2" = "x--help"; then
-       # Could not run --version or --help.  This is probably someone
-       # running `$TOOL --version' or `$TOOL --help' to check whether
-       # $TOOL exists and not knowing $TOOL uses missing.
-       exit 1
-    fi
-    ;;
-esac
-
-# If it does not exist, or fails to run (possibly an outdated version),
-# try to emulate it.
-case $program in
-  aclocal*)
-    echo 1>&2 "\
-WARNING: \`$1' is $msg.  You should only need it if
-         you modified \`acinclude.m4' or \`${configure_ac}'.  You might want
-         to install the \`Automake' and \`Perl' packages.  Grab them from
-         any GNU archive site."
-    touch aclocal.m4
-    ;;
-
-  autoconf*)
-    echo 1>&2 "\
-WARNING: \`$1' is $msg.  You should only need it if
-         you modified \`${configure_ac}'.  You might want to install the
-         \`Autoconf' and \`GNU m4' packages.  Grab them from any GNU
-         archive site."
-    touch configure
-    ;;
-
-  autoheader*)
-    echo 1>&2 "\
-WARNING: \`$1' is $msg.  You should only need it if
-         you modified \`acconfig.h' or \`${configure_ac}'.  You might want
-         to install the \`Autoconf' and \`GNU m4' packages.  Grab them
-         from any GNU archive site."
-    files=`sed -n 's/^[ ]*A[CM]_CONFIG_HEADER(\([^)]*\)).*/\1/p' ${configure_ac}`
-    test -z "$files" && files="config.h"
-    touch_files=
-    for f in $files; do
-      case $f in
-      *:*) touch_files="$touch_files "`echo "$f" |
-				       sed -e 's/^[^:]*://' -e 's/:.*//'`;;
-      *) touch_files="$touch_files $f.in";;
-      esac
-    done
-    touch $touch_files
-    ;;
-
-  automake*)
-    echo 1>&2 "\
-WARNING: \`$1' is $msg.  You should only need it if
-         you modified \`Makefile.am', \`acinclude.m4' or \`${configure_ac}'.
-         You might want to install the \`Automake' and \`Perl' packages.
-         Grab them from any GNU archive site."
-    find . -type f -name Makefile.am -print |
-	   sed 's/\.am$/.in/' |
-	   while read f; do touch "$f"; done
-    ;;
-
-  autom4te*)
-    echo 1>&2 "\
-WARNING: \`$1' is needed, but is $msg.
-         You might have modified some files without having the
-         proper tools for further handling them.
-         You can get \`$1' as part of \`Autoconf' from any GNU
-         archive site."
-
-    file=`echo "$*" | sed -n "$sed_output"`
-    test -z "$file" && file=`echo "$*" | sed -n "$sed_minuso"`
-    if test -f "$file"; then
-	touch $file
-    else
-	test -z "$file" || exec >$file
-	echo "#! /bin/sh"
-	echo "# Created by GNU Automake missing as a replacement of"
-	echo "#  $ $@"
-	echo "exit 0"
-	chmod +x $file
-	exit 1
-    fi
-    ;;
-
-  bison*|yacc*)
-    echo 1>&2 "\
-WARNING: \`$1' $msg.  You should only need it if
-         you modified a \`.y' file.  You may need the \`Bison' package
-         in order for those modifications to take effect.  You can get
-         \`Bison' from any GNU archive site."
-    rm -f y.tab.c y.tab.h
-    if test $# -ne 1; then
-        eval LASTARG=\${$#}
-	case $LASTARG in
-	*.y)
-	    SRCFILE=`echo "$LASTARG" | sed 's/y$/c/'`
-	    if test -f "$SRCFILE"; then
-	         cp "$SRCFILE" y.tab.c
-	    fi
-	    SRCFILE=`echo "$LASTARG" | sed 's/y$/h/'`
-	    if test -f "$SRCFILE"; then
-	         cp "$SRCFILE" y.tab.h
-	    fi
-	  ;;
-	esac
-    fi
-    if test ! -f y.tab.h; then
-	echo >y.tab.h
-    fi
-    if test ! -f y.tab.c; then
-	echo 'main() { return 0; }' >y.tab.c
-    fi
-    ;;
-
-  lex*|flex*)
-    echo 1>&2 "\
-WARNING: \`$1' is $msg.  You should only need it if
-         you modified a \`.l' file.  You may need the \`Flex' package
-         in order for those modifications to take effect.  You can get
-         \`Flex' from any GNU archive site."
-    rm -f lex.yy.c
-    if test $# -ne 1; then
-        eval LASTARG=\${$#}
-	case $LASTARG in
-	*.l)
-	    SRCFILE=`echo "$LASTARG" | sed 's/l$/c/'`
-	    if test -f "$SRCFILE"; then
-	         cp "$SRCFILE" lex.yy.c
-	    fi
-	  ;;
-	esac
-    fi
-    if test ! -f lex.yy.c; then
-	echo 'main() { return 0; }' >lex.yy.c
-    fi
-    ;;
-
-  help2man*)
-    echo 1>&2 "\
-WARNING: \`$1' is $msg.  You should only need it if
-	 you modified a dependency of a manual page.  You may need the
-	 \`Help2man' package in order for those modifications to take
-	 effect.  You can get \`Help2man' from any GNU archive site."
-
-    file=`echo "$*" | sed -n "$sed_output"`
-    test -z "$file" && file=`echo "$*" | sed -n "$sed_minuso"`
-    if test -f "$file"; then
-	touch $file
-    else
-	test -z "$file" || exec >$file
-	echo ".ab help2man is required to generate this page"
-	exit $?
-    fi
-    ;;
-
-  makeinfo*)
-    echo 1>&2 "\
-WARNING: \`$1' is $msg.  You should only need it if
-         you modified a \`.texi' or \`.texinfo' file, or any other file
-         indirectly affecting the aspect of the manual.  The spurious
-         call might also be the consequence of using a buggy \`make' (AIX,
-         DU, IRIX).  You might want to install the \`Texinfo' package or
-         the \`GNU make' package.  Grab either from any GNU archive site."
-    # The file to touch is that specified with -o ...
-    file=`echo "$*" | sed -n "$sed_output"`
-    test -z "$file" && file=`echo "$*" | sed -n "$sed_minuso"`
-    if test -z "$file"; then
-      # ... or it is the one specified with @setfilename ...
-      infile=`echo "$*" | sed 's/.* \([^ ]*\) *$/\1/'`
-      file=`sed -n '
-	/^@setfilename/{
-	  s/.* \([^ ]*\) *$/\1/
-	  p
-	  q
-	}' $infile`
-      # ... or it is derived from the source name (dir/f.texi becomes f.info)
-      test -z "$file" && file=`echo "$infile" | sed 's,.*/,,;s,.[^.]*$,,'`.info
-    fi
-    # If the file does not exist, the user really needs makeinfo;
-    # let's fail without touching anything.
-    test -f $file || exit 1
-    touch $file
-    ;;
+# Run the given program, remember its exit status.
+"$@"; st=$?
+
+# If it succeeded, we are done.
+test $st -eq 0 && exit 0
+
+# Also exit now if we it failed (or wasn't found), and '--version' was
+# passed; such an option is passed most likely to detect whether the
+# program is present and works.
+case $2 in --version|--help) exit $st;; esac
+
+# Exit code 63 means version mismatch.  This often happens when the user
+# tries to use an ancient version of a tool on a file that requires a
+# minimum version.
+if test $st -eq 63; then
+  msg="probably too old"
+elif test $st -eq 127; then
+  # Program was missing.
+  msg="missing on your system"
+else
+  # Program was found and executed, but failed.  Give up.
+  exit $st
+fi
 
-  *)
-    echo 1>&2 "\
-WARNING: \`$1' is needed, and is $msg.
-         You might have modified some files without having the
-         proper tools for further handling them.  Check the \`README' file,
-         it often tells you about the needed prerequisites for installing
-         this package.  You may also peek at any GNU archive site, in case
-         some other package would contain this missing \`$1' program."
-    exit 1
+perl_URL=http://www.perl.org/
+flex_URL=http://flex.sourceforge.net/
+gnu_software_URL=http://www.gnu.org/software
+
+program_details ()
+{
+  case $1 in
+    aclocal|automake)
+      echo "The '$1' program is part of the GNU Automake package:"
+      echo "<$gnu_software_URL/automake>"
+      echo "It also requires GNU Autoconf, GNU m4 and Perl in order to run:"
+      echo "<$gnu_software_URL/autoconf>"
+      echo "<$gnu_software_URL/m4/>"
+      echo "<$perl_URL>"
+      ;;
+    autoconf|autom4te|autoheader)
+      echo "The '$1' program is part of the GNU Autoconf package:"
+      echo "<$gnu_software_URL/autoconf/>"
+      echo "It also requires GNU m4 and Perl in order to run:"
+      echo "<$gnu_software_URL/m4/>"
+      echo "<$perl_URL>"
+      ;;
+  esac
+}
+
+give_advice ()
+{
+  # Normalize program name to check for.
+  normalized_program=`echo "$1" | sed '
+    s/^gnu-//; t
+    s/^gnu//; t
+    s/^g//; t'`
+
+  printf '%s\n' "'$1' is $msg."
+
+  configure_deps="'configure.ac' or m4 files included by 'configure.ac'"
+  case $normalized_program in
+    autoconf*)
+      echo "You should only need it if you modified 'configure.ac',"
+      echo "or m4 files included by it."
+      program_details 'autoconf'
+      ;;
+    autoheader*)
+      echo "You should only need it if you modified 'acconfig.h' or"
+      echo "$configure_deps."
+      program_details 'autoheader'
+      ;;
+    automake*)
+      echo "You should only need it if you modified 'Makefile.am' or"
+      echo "$configure_deps."
+      program_details 'automake'
+      ;;
+    aclocal*)
+      echo "You should only need it if you modified 'acinclude.m4' or"
+      echo "$configure_deps."
+      program_details 'aclocal'
+      ;;
+   autom4te*)
+      echo "You might have modified some maintainer files that require"
+      echo "the 'autom4te' program to be rebuilt."
+      program_details 'autom4te'
+      ;;
+    bison*|yacc*)
+      echo "You should only need it if you modified a '.y' file."
+      echo "You may want to install the GNU Bison package:"
+      echo "<$gnu_software_URL/bison/>"
+      ;;
+    lex*|flex*)
+      echo "You should only need it if you modified a '.l' file."
+      echo "You may want to install the Fast Lexical Analyzer package:"
+      echo "<$flex_URL>"
+      ;;
+    help2man*)
+      echo "You should only need it if you modified a dependency" \
+           "of a man page."
+      echo "You may want to install the GNU Help2man package:"
+      echo "<$gnu_software_URL/help2man/>"
     ;;
-esac
-
-exit 0
+    makeinfo*)
+      echo "You should only need it if you modified a '.texi' file, or"
+      echo "any other file indirectly affecting the aspect of the manual."
+      echo "You might want to install the Texinfo package:"
+      echo "<$gnu_software_URL/texinfo/>"
+      echo "The spurious makeinfo call might also be the consequence of"
+      echo "using a buggy 'make' (AIX, DU, IRIX), in which case you might"
+      echo "want to install GNU make:"
+      echo "<$gnu_software_URL/make/>"
+      ;;
+    *)
+      echo "You might have modified some files without having the proper"
+      echo "tools for further handling them.  Check the 'README' file, it"
+      echo "often tells you about the needed prerequisites for installing"
+      echo "this package.  You may also peek at any GNU archive site, in"
+      echo "case some other package contains this missing '$1' program."
+      ;;
+  esac
+}
+
+give_advice "$1" | sed -e '1s/^/WARNING: /' \
+                       -e '2,$s/^/         /' >&2
+
+# Propagate the correct exit status (expected to be 127 for a program
+# not found, 63 for a program that failed due to version mismatch).
+exit $st
 
 # Local variables:
 # eval: (add-hook 'write-file-hooks 'time-stamp)