gzip: fix bug with any upper case custom ('-S'-specified) suffix

[debian/gzip] / bootstrap

#! /bin/sh
# Print a version string.
scriptversion=2017-09-19.08; # UTC

# Bootstrap this package from checked-out sources.

# Copyright (C) 2003-2017 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
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.

# Originally written by Paul Eggert.  The canonical version of this
# script is maintained as build-aux/bootstrap in gnulib, however, to
# be useful to your project, you should place a copy of it under
# version control in the top-level directory of your project.  The
# intent is that all customization can be done with a bootstrap.conf
# file also maintained in your version control; gnulib comes with a
# template build-aux/bootstrap.conf to get you started.

# Please report bugs or propose patches to bug-gnulib@gnu.org.

nl='
'

# Ensure file names are sorted consistently across platforms.
LC_ALL=C
export LC_ALL

# Ensure that CDPATH is not set.  Otherwise, the output from cd
# would cause trouble in at least one use below.
(unset CDPATH) >/dev/null 2>&1 && unset CDPATH

local_gl_dir=gl

# Honor $PERL, but work even if there is none.
PERL="${PERL-perl}"

me=$0

usage() {
  cat <<EOF
Usage: $me [OPTION]...
Bootstrap this package from the checked-out sources.

Options:
 --gnulib-srcdir=DIRNAME  specify the local directory where gnulib
                          sources reside.  Use this if you already
                          have gnulib sources on your machine, and
                          do not want to waste your bandwidth downloading
                          them again.  Defaults to \$GNULIB_SRCDIR
 --bootstrap-sync         if this bootstrap script is not identical to
                          the version in the local gnulib sources,
                          update this script, and then restart it with
                          /bin/sh or the shell \$CONFIG_SHELL
 --no-bootstrap-sync      do not check whether bootstrap is out of sync
 --copy                   copy files instead of creating symbolic links
 --force                  attempt to bootstrap even if the sources seem
                          not to have been checked out
 --no-git                 do not use git to update gnulib.  Requires that
                          --gnulib-srcdir point to a correct gnulib snapshot
 --skip-po                do not download po files

If the file $me.conf exists in the same directory as this script, its
contents are read as shell variables to configure the bootstrap.

For build prerequisites, environment variables like \$AUTOCONF and \$AMTAR
are honored.

Running without arguments will suffice in most cases.
EOF
}

# warnf_ FORMAT-STRING ARG1...
warnf_ ()
{
  warnf_format_=$1
  shift
  nl='
'
  case $* in
    *$nl*) me_=$(printf "$me"|tr "$nl|" '??')
       printf "$warnf_format_" "$@" | sed "s|^|$me_: |" ;;
    *) printf "$me: $warnf_format_" "$@" ;;
  esac >&2
}

# warn_ WORD1...
warn_ ()
{
  # If IFS does not start with ' ', set it and emit the warning in a subshell.
  case $IFS in
    ' '*) warnf_ '%s\n' "$*";;
    *)    (IFS=' '; warn_ "$@");;
  esac
}

# die WORD1...
die() { warn_ "$@"; exit 1; }

# Configuration.

# Name of the Makefile.am
gnulib_mk=gnulib.mk

# List of gnulib modules needed.
gnulib_modules=

# Any gnulib files needed that are not in modules.
gnulib_files=

: ${AUTOPOINT=autopoint}
: ${AUTORECONF=autoreconf}

# A function to be called right after gnulib-tool is run.
# Override it via your own definition in bootstrap.conf.
bootstrap_post_import_hook() { :; }

# A function to be called after everything else in this script.
# Override it via your own definition in bootstrap.conf.
bootstrap_epilogue() { :; }

# The command to download all .po files for a specified domain into
# a specified directory.  Fill in the first %s is the domain name, and
# the second with the destination directory.  Use rsync's -L and -r
# options because the latest/%s directory and the .po files within are
# all symlinks.
po_download_command_format=\
"rsync --delete --exclude '*.s1' -Lrtvz \
 'translationproject.org::tp/latest/%s/' '%s'"

# Fallback for downloading .po files (if rsync fails).
po_download_command_format2=\
"wget --mirror -nd -q -np -A.po -P '%s' \
 https://translationproject.org/latest/%s/"

# Prefer a non-empty tarname (4th argument of AC_INIT if given), else
# fall back to the package name (1st argument with munging)
extract_package_name='
  /^AC_INIT(\[*/{
     s///
     /^[^,]*,[^,]*,[^,]*,[ []*\([^][ ,)]\)/{
       s//\1/
       s/[],)].*//
       p
       q
     }
     s/[],)].*//
     s/^GNU //
     y/ABCDEFGHIJKLMNOPQRSTUVWXYZ/abcdefghijklmnopqrstuvwxyz/
     s/[^abcdefghijklmnopqrstuvwxyz0123456789_]/-/g
     p
  }
'
package=$(sed -n "$extract_package_name" configure.ac) \
  || die 'cannot find package name in configure.ac'
gnulib_name=lib$package

build_aux=build-aux
source_base=lib
m4_base=m4
doc_base=doc
tests_base=tests
gnulib_extra_files=''

# Additional gnulib-tool options to use.  Use "\newline" to break lines.
gnulib_tool_option_extras=

# Other locale categories that need message catalogs.
EXTRA_LOCALE_CATEGORIES=

# Additional xgettext options to use.  Use "\\\newline" to break lines.
XGETTEXT_OPTIONS='\\\
 --flag=_:1:pass-c-format\\\
 --flag=N_:1:pass-c-format\\\
 --flag=error:3:c-format --flag=error_at_line:5:c-format\\\
'

# Package bug report address and copyright holder for gettext files
COPYRIGHT_HOLDER='Free Software Foundation, Inc.'
MSGID_BUGS_ADDRESS=bug-$package@gnu.org

# Files we don't want to import.
excluded_files=

# File that should exist in the top directory of a checked out hierarchy,
# but not in a distribution tarball.
checkout_only_file=README-hacking

# Whether to use copies instead of symlinks.
copy=false

# Set this to '.cvsignore .gitignore' in bootstrap.conf if you want
# those files to be generated in directories like lib/, m4/, and po/.
# Or set it to 'auto' to make this script select which to use based
# on which version control system (if any) is used in the source directory.
vc_ignore=auto

# Set this to true in bootstrap.conf to enable --bootstrap-sync by
# default.
bootstrap_sync=false

# Use git to update gnulib sources
use_git=true

check_exists() {
  if test "$1" = "--verbose"; then
    ($2 --version </dev/null) >/dev/null 2>&1
    if test $? -ge 126; then
      # If not found, run with diagnostics as one may be
      # presented with env variables to set to find the right version
      ($2 --version </dev/null)
    fi
  else
    ($1 --version </dev/null) >/dev/null 2>&1
  fi

  test $? -lt 126
}

# find_tool ENVVAR NAMES...
# -------------------------
# Search for a required program.  Use the value of ENVVAR, if set,
# otherwise find the first of the NAMES that can be run.
# If found, set ENVVAR to the program name, die otherwise.
#
# FIXME: code duplication, see also gnu-web-doc-update.
find_tool ()
{
  find_tool_envvar=$1
  shift
  find_tool_names=$@
  eval "find_tool_res=\$$find_tool_envvar"
  if test x"$find_tool_res" = x; then
    for i; do
      if check_exists $i; then
        find_tool_res=$i
        break
      fi
    done
  fi
  if test x"$find_tool_res" = x; then
    warn_ "one of these is required: $find_tool_names;"
    die   "alternatively set $find_tool_envvar to a compatible tool"
  fi
  eval "$find_tool_envvar=\$find_tool_res"
  eval "export $find_tool_envvar"
}

# Override the default configuration, if necessary.
# Make sure that bootstrap.conf is sourced from the current directory
# if we were invoked as "sh bootstrap".
case "$0" in
  */*) test -r "$0.conf" && . "$0.conf" ;;
  *) test -r "$0.conf" && . ./"$0.conf" ;;
esac

# Extra files from gnulib, which override files from other sources.
test -z "${gnulib_extra_files}" && \
  gnulib_extra_files="
        build-aux/install-sh
        build-aux/mdate-sh
        build-aux/texinfo.tex
        build-aux/depcomp
        build-aux/config.guess
        build-aux/config.sub
        doc/INSTALL
"

if test "$vc_ignore" = auto; then
  vc_ignore=
  test -d .git && vc_ignore=.gitignore
  test -d CVS && vc_ignore="$vc_ignore .cvsignore"
fi

# Translate configuration into internal form.

# Parse options.

for option
do
  case $option in
  --help)
    usage
    exit;;
  --gnulib-srcdir=*)
    GNULIB_SRCDIR=${option#--gnulib-srcdir=};;
  --skip-po)
    SKIP_PO=t;;
  --force)
    checkout_only_file=;;
  --copy)
    copy=true;;
  --bootstrap-sync)
    bootstrap_sync=true;;
  --no-bootstrap-sync)
    bootstrap_sync=false;;
  --no-git)
    use_git=false;;
  *)
    die "$option: unknown option";;
  esac
done

$use_git || test -d "$GNULIB_SRCDIR" \
  || die "Error: --no-git requires --gnulib-srcdir"

if test -n "$checkout_only_file" && test ! -r "$checkout_only_file"; then
  die "Bootstrapping from a non-checked-out distribution is risky."
fi

# Strip blank and comment lines to leave significant entries.
gitignore_entries() {
  sed '/^#/d; /^$/d' "$@"
}

# If $STR is not already on a line by itself in $FILE, insert it at the start.
# Entries are inserted at the start of the ignore list to ensure existing
# entries starting with ! are not overridden.  Such entries support
# whitelisting exceptions after a more generic blacklist pattern.
insert_if_absent() {
  file=$1
  str=$2
  test -f $file || touch $file
  test -r $file || die "Error: failed to read ignore file: $file"
  duplicate_entries=$(gitignore_entries $file | sort | uniq -d)
  if [ "$duplicate_entries" ] ; then
    die "Error: Duplicate entries in $file: " $duplicate_entries
  fi
  linesold=$(gitignore_entries $file | wc -l)
  linesnew=$( { echo "$str"; cat $file; } | gitignore_entries | sort -u | wc -l)
  if [ $linesold != $linesnew ] ; then
    { echo "$str" | cat - $file > $file.bak && mv $file.bak $file; } \
      || die "insert_if_absent $file $str: failed"
  fi
}

# Adjust $PATTERN for $VC_IGNORE_FILE and insert it with
# insert_if_absent.
insert_vc_ignore() {
  vc_ignore_file="$1"
  pattern="$2"
  case $vc_ignore_file in
  *.gitignore)
    # A .gitignore entry that does not start with '/' applies
    # recursively to subdirectories, so prepend '/' to every
    # .gitignore entry.
    pattern=$(echo "$pattern" | sed s,^,/,);;
  esac
  insert_if_absent "$vc_ignore_file" "$pattern"
}

# Die if there is no AC_CONFIG_AUX_DIR($build_aux) line in configure.ac.
found_aux_dir=no
grep '^[         ]*AC_CONFIG_AUX_DIR(\['"$build_aux"'\])' configure.ac \
    >/dev/null && found_aux_dir=yes
grep '^[         ]*AC_CONFIG_AUX_DIR('"$build_aux"')' configure.ac \
    >/dev/null && found_aux_dir=yes
test $found_aux_dir = yes \
  || die "configure.ac lacks 'AC_CONFIG_AUX_DIR([$build_aux])'; add it"

# If $build_aux doesn't exist, create it now, otherwise some bits
# below will malfunction.  If creating it, also mark it as ignored.
if test ! -d $build_aux; then
  mkdir $build_aux
  for dot_ig in x $vc_ignore; do
    test $dot_ig = x && continue
    insert_vc_ignore $dot_ig $build_aux
  done
fi

# Note this deviates from the version comparison in automake
# in that it treats 1.5 < 1.5.0, and treats 1.4.4a < 1.4-p3a
# but this should suffice as we won't be specifying old
# version formats or redundant trailing .0 in bootstrap.conf.
# If we did want full compatibility then we should probably
# use m4_version_compare from autoconf.
sort_ver() { # sort -V is not generally available
  ver1="$1"
  ver2="$2"

  # split on '.' and compare each component
  i=1
  while : ; do
    p1=$(echo "$ver1" | cut -d. -f$i)
    p2=$(echo "$ver2" | cut -d. -f$i)
    if [ ! "$p1" ]; then
      echo "$1 $2"
      break
    elif [ ! "$p2" ]; then
      echo "$2 $1"
      break
    elif [ ! "$p1" = "$p2" ]; then
      if [ "$p1" -gt "$p2" ] 2>/dev/null; then # numeric comparison
        echo "$2 $1"
      elif [ "$p2" -gt "$p1" ] 2>/dev/null; then # numeric comparison
        echo "$1 $2"
      else # numeric, then lexicographic comparison
        lp=$(printf "$p1\n$p2\n" | LANG=C sort -n | tail -n1)
        if [ "$lp" = "$p2" ]; then
          echo "$1 $2"
        else
          echo "$2 $1"
        fi
      fi
      break
    fi
    i=$(($i+1))
  done
}

get_version_sed='
# Move version to start of line.
s/.*[v ]\([0-9]\)/\1/

# Skip lines that do not start with version.
/^[0-9]/!d

# Remove characters after the version.
s/[^.a-z0-9-].*//

# The first component must be digits only.
s/^\([0-9]*\)[a-z-].*/\1/

#the following essentially does s/5.005/5.5/
s/\.0*\([1-9]\)/.\1/g
p
q'

get_version() {
  app=$1

  $app --version >/dev/null 2>&1 || { $app --version; return 1; }

  $app --version 2>&1 | sed -n "$get_version_sed"
}

check_versions() {
  ret=0

  while read app req_ver; do
    # We only need libtoolize from the libtool package.
    if test "$app" = libtool; then
      app=libtoolize
    fi
    # Exempt git if --no-git is in effect.
    if test "$app" = git; then
      $use_git || continue
    fi
    # Honor $APP variables ($TAR, $AUTOCONF, etc.)
    appvar=$(echo $app | LC_ALL=C tr '[a-z]-' '[A-Z]_')
    test "$appvar" = TAR && appvar=AMTAR
    case $appvar in
        GZIP) ;; # Do not use $GZIP:  it contains gzip options.
        PERL::*) ;; # Keep perl modules as-is
        *) eval "app=\${$appvar-$app}" ;;
    esac

    # Handle the still-experimental Automake-NG programs specially.
    # They remain named as the mainstream Automake programs ("automake",
    # and "aclocal") to avoid gratuitous incompatibilities with
    # pre-existing usages (by, say, autoreconf, or custom autogen.sh
    # scripts), but correctly identify themselves (as being part of
    # "GNU automake-ng") when asked their version.
    case $app in
      automake-ng|aclocal-ng)
        app=${app%-ng}
        ($app --version | grep '(GNU automake-ng)') >/dev/null 2>&1 || {
          warn_ "Error: '$app' not found or not from Automake-NG"
          ret=1
          continue
        } ;;
      # Another check is for perl modules.  These can be written as
      # e.g. perl::XML::XPath in case of XML::XPath module, etc.
      perl::*)
        # Extract module name
        app="${app#perl::}"
        if ! $PERL -m"$app" -e 'exit 0' >/dev/null 2>&1; then
          warn_ "Error: perl module '$app' not found"
          ret=1
        fi
        continue
        ;;
    esac
    if [ "$req_ver" = "-" ]; then
      # Merely require app to exist; not all prereq apps are well-behaved
      # so we have to rely on $? rather than get_version.
      if ! check_exists --verbose $app; then
        warn_ "Error: '$app' not found"
        ret=1
      fi
    else
      # Require app to produce a new enough version string.
      inst_ver=$(get_version $app)
      if [ ! "$inst_ver" ]; then
        warn_ "Error: '$app' not found"
        ret=1
      else
        latest_ver=$(sort_ver $req_ver $inst_ver | cut -d' ' -f2)
        if [ ! "$latest_ver" = "$inst_ver" ]; then
          warnf_ '%s\n'                                        \
              "Error: '$app' version == $inst_ver is too old"  \
              "       '$app' version >= $req_ver is required"
          ret=1
        fi
      fi
    fi
  done

  return $ret
}

print_versions() {
  echo "Program    Min_version"
  echo "----------------------"
  printf %s "$buildreq"
  echo "----------------------"
  # can't depend on column -t
}

# Find sha1sum, named gsha1sum on MacPorts, shasum on Mac OS X 10.6.
# Also find the compatible sha1 utility on the BSDs
if test x"$SKIP_PO" = x; then
  find_tool SHA1SUM sha1sum gsha1sum shasum sha1
fi

use_libtool=0
# We'd like to use grep -E, to see if any of LT_INIT,
# AC_PROG_LIBTOOL, AM_PROG_LIBTOOL is used in configure.ac,
# but that's not portable enough (e.g., for Solaris).
grep '^[         ]*A[CM]_PROG_LIBTOOL' configure.ac >/dev/null \
  && use_libtool=1
grep '^[         ]*LT_INIT' configure.ac >/dev/null \
  && use_libtool=1
if test $use_libtool = 1; then
  find_tool LIBTOOLIZE glibtoolize libtoolize
fi

# gnulib-tool requires at least automake and autoconf.
# If either is not listed, add it (with minimum version) as a prerequisite.
case $buildreq in
  *automake*) ;;
  *) buildreq="automake 1.9
$buildreq" ;;
esac
case $buildreq in
  *autoconf*) ;;
  *) buildreq="autoconf 2.59
$buildreq" ;;
esac

# When we can deduce that gnulib-tool will require patch,
# and when patch is not already listed as a prerequisite, add it, too.
if test -d "$local_gl_dir" \
    && ! find "$local_gl_dir" -name '*.diff' -exec false {} +; then
  case $buildreq in
    *patch*) ;;
    *) buildreq="patch -
$buildreq" ;;
  esac
fi

if ! printf "$buildreq" | check_versions; then
  echo >&2
  if test -f README-prereq; then
    die "See README-prereq for how to get the prerequisite programs"
  else
    die "Please install the prerequisite programs"
  fi
fi

# Warn the user if autom4te appears to be broken; this causes known
# issues with at least gettext 0.18.3.
probe=$(echo 'm4_quote([hi])' | autom4te -l M4sugar -t 'm4_quote:$%' -)
if test "x$probe" != xhi; then
  warn_ "WARNING: your autom4te wrapper eats stdin;"
  warn_ "if bootstrap fails, consider upgrading your autotools"
fi

echo "$0: Bootstrapping from checked-out $package sources..."

# See if we can use gnulib's git-merge-changelog merge driver.
if $use_git && test -d .git && check_exists git; then
  if git config merge.merge-changelog.driver >/dev/null ; then
    :
  elif check_exists git-merge-changelog; then
    echo "$0: initializing git-merge-changelog driver"
    git config merge.merge-changelog.name 'GNU-style ChangeLog merge driver'
    git config merge.merge-changelog.driver 'git-merge-changelog %O %A %B'
  else
    echo "$0: consider installing git-merge-changelog from gnulib"
  fi
fi


cleanup_gnulib() {
  status=$?
  rm -fr "$gnulib_path"
  exit $status
}

git_modules_config () {
  test -f .gitmodules && git config --file .gitmodules "$@"
}

if $use_git; then
  gnulib_path=$(git_modules_config submodule.gnulib.path)
  test -z "$gnulib_path" && gnulib_path=gnulib
fi

# Get gnulib files.  Populate $GNULIB_SRCDIR, possibly updating a
# submodule, for use in the rest of the script.

case ${GNULIB_SRCDIR--} in
-)
  # Note that $use_git is necessarily true in this case.
  if git_modules_config submodule.gnulib.url >/dev/null; then
    echo "$0: getting gnulib files..."
    git submodule init -- "$gnulib_path" || exit $?
    git submodule update -- "$gnulib_path" || exit $?

  elif [ ! -d "$gnulib_path" ]; then
    echo "$0: getting gnulib files..."

    trap cleanup_gnulib 1 2 13 15

    shallow=
    git clone -h 2>&1 | grep -- --depth > /dev/null && shallow='--depth 2'
    git clone $shallow git://git.sv.gnu.org/gnulib "$gnulib_path" ||
      cleanup_gnulib

    trap - 1 2 13 15
  fi
  GNULIB_SRCDIR=$gnulib_path
  ;;
*)
  # Use GNULIB_SRCDIR directly or as a reference.
  if $use_git && test -d "$GNULIB_SRCDIR"/.git && \
        git_modules_config submodule.gnulib.url >/dev/null; then
    echo "$0: getting gnulib files..."
    if git submodule -h|grep -- --reference > /dev/null; then
      # Prefer the one-liner available in git 1.6.4 or newer.
      git submodule update --init --reference "$GNULIB_SRCDIR" \
        "$gnulib_path" || exit $?
    else
      # This fallback allows at least git 1.5.5.
      if test -f "$gnulib_path"/gnulib-tool; then
        # Since file already exists, assume submodule init already complete.
        git submodule update -- "$gnulib_path" || exit $?
      else
        # Older git can't clone into an empty directory.
        rmdir "$gnulib_path" 2>/dev/null
        git clone --reference "$GNULIB_SRCDIR" \
          "$(git_modules_config submodule.gnulib.url)" "$gnulib_path" \
          && git submodule init -- "$gnulib_path" \
          && git submodule update -- "$gnulib_path" \
          || exit $?
      fi
    fi
    GNULIB_SRCDIR=$gnulib_path
  fi
  ;;
esac

# $GNULIB_SRCDIR now points to the version of gnulib to use, and
# we no longer need to use git or $gnulib_path below here.

if $bootstrap_sync; then
  cmp -s "$0" "$GNULIB_SRCDIR/build-aux/bootstrap" || {
    echo "$0: updating bootstrap and restarting..."
    case $(sh -c 'echo "$1"' -- a) in
      a) ignored=--;;
      *) ignored=ignored;;
    esac
    exec sh -c \
      'cp "$1" "$2" && shift && exec "${CONFIG_SHELL-/bin/sh}" "$@"' \
      $ignored "$GNULIB_SRCDIR/build-aux/bootstrap" \
      "$0" "$@" --no-bootstrap-sync
  }
fi

gnulib_tool=$GNULIB_SRCDIR/gnulib-tool
<$gnulib_tool || exit $?

# Get translations.

download_po_files() {
  subdir=$1
  domain=$2
  echo "$me: getting translations into $subdir for $domain..."
  cmd=$(printf "$po_download_command_format" "$domain" "$subdir")
  eval "$cmd" && return
  # Fallback to HTTPS.
  cmd=$(printf "$po_download_command_format2" "$subdir" "$domain")
  eval "$cmd"
}

# Mirror .po files to $po_dir/.reference and copy only the new
# or modified ones into $po_dir.  Also update $po_dir/LINGUAS.
# Note po files that exist locally only are left in $po_dir but will
# not be included in LINGUAS and hence will not be distributed.
update_po_files() {
  # Directory containing primary .po files.
  # Overwrite them only when we're sure a .po file is new.
  po_dir=$1
  domain=$2

  # Mirror *.po files into this dir.
  # Usually contains *.s1 checksum files.
  ref_po_dir="$po_dir/.reference"

  test -d $ref_po_dir || mkdir $ref_po_dir || return
  download_po_files $ref_po_dir $domain \
    && ls "$ref_po_dir"/*.po 2>/dev/null |
      sed 's|.*/||; s|\.po$||' > "$po_dir/LINGUAS" || return

  langs=$(cd $ref_po_dir && echo *.po | sed 's/\.po//g')
  test "$langs" = '*' && langs=x
  for po in $langs; do
    case $po in x) continue;; esac
    new_po="$ref_po_dir/$po.po"
    cksum_file="$ref_po_dir/$po.s1"
    if ! test -f "$cksum_file" ||
        ! test -f "$po_dir/$po.po" ||
        ! $SHA1SUM -c "$cksum_file" < "$new_po" > /dev/null 2>&1; then
      echo "$me: updated $po_dir/$po.po..."
      cp "$new_po" "$po_dir/$po.po" \
          && $SHA1SUM < "$new_po" > "$cksum_file" || return
    fi
  done
}

case $SKIP_PO in
'')
  if test -d po; then
    update_po_files po $package || exit
  fi

  if test -d runtime-po; then
    update_po_files runtime-po $package-runtime || exit
  fi;;
esac

symlink_to_dir()
{
  src=$1/$2
  dst=${3-$2}

  test -f "$src" && {

    # If the destination directory doesn't exist, create it.
    # This is required at least for "lib/uniwidth/cjk.h".
    dst_dir=$(dirname "$dst")
    if ! test -d "$dst_dir"; then
      mkdir -p "$dst_dir"

      # If we've just created a directory like lib/uniwidth,
      # tell version control system(s) it's ignorable.
      # FIXME: for now, this does only one level
      parent=$(dirname "$dst_dir")
      for dot_ig in x $vc_ignore; do
        test $dot_ig = x && continue
        ig=$parent/$dot_ig
        insert_vc_ignore $ig "${dst_dir##*/}"
      done
    fi

    if $copy; then
      {
        test ! -h "$dst" || {
          echo "$me: rm -f $dst" &&
          rm -f "$dst"
        }
      } &&
      test -f "$dst" &&
      cmp -s "$src" "$dst" || {
        echo "$me: cp -fp $src $dst" &&
        cp -fp "$src" "$dst"
      }
    else
      # Leave any existing symlink alone, if it already points to the source,
      # so that broken build tools that care about symlink times
      # aren't confused into doing unnecessary builds.  Conversely, if the
      # existing symlink's timestamp is older than the source, make it afresh,
      # so that broken tools aren't confused into skipping needed builds.  See
      # <https://lists.gnu.org/archive/html/bug-gnulib/2011-05/msg00326.html>.
      test -h "$dst" &&
      src_ls=$(ls -diL "$src" 2>/dev/null) && set $src_ls && src_i=$1 &&
      dst_ls=$(ls -diL "$dst" 2>/dev/null) && set $dst_ls && dst_i=$1 &&
      test "$src_i" = "$dst_i" &&
      both_ls=$(ls -dt "$src" "$dst") &&
      test "X$both_ls" = "X$dst$nl$src" || {
        dot_dots=
        case $src in
        /*) ;;
        *)
          case /$dst/ in
          *//* | */../* | */./* | /*/*/*/*/*/)
             die "invalid symlink calculation: $src -> $dst";;
          /*/*/*/*/)    dot_dots=../../../;;
          /*/*/*/)      dot_dots=../../;;
          /*/*/)        dot_dots=../;;
          esac;;
        esac

        echo "$me: ln -fs $dot_dots$src $dst" &&
        ln -fs "$dot_dots$src" "$dst"
      }
    fi
  }
}

version_controlled_file() {
  parent=$1
  file=$2
  if test -d .git; then
    git rm -n "$file" > /dev/null 2>&1
  elif test -d .svn; then
    svn log -r HEAD "$file" > /dev/null 2>&1
  elif test -d CVS; then
    grep -F "/${file##*/}/" "$parent/CVS/Entries" 2>/dev/null |
             grep '^/[^/]*/[0-9]' > /dev/null
  else
    warn_ "no version control for $file?"
    false
  fi
}

# NOTE: we have to be careful to run both autopoint and libtoolize
# before gnulib-tool, since gnulib-tool is likely to provide newer
# versions of files "installed" by these two programs.
# Then, *after* gnulib-tool (see below), we have to be careful to
# run autoreconf in such a way that it does not run either of these
# two just-pre-run programs.

# Import from gettext.
with_gettext=yes
grep '^[         ]*AM_GNU_GETTEXT_VERSION(' configure.ac >/dev/null || \
    with_gettext=no

if test $with_gettext = yes || test $use_libtool = 1; then

  tempbase=.bootstrap$$
  trap "rm -f $tempbase.0 $tempbase.1" 1 2 13 15

  > $tempbase.0 > $tempbase.1 &&
  find . ! -type d -print | sort > $tempbase.0 || exit

  if test $with_gettext = yes; then
    # Released autopoint has the tendency to install macros that have been
    # obsoleted in current gnulib, so run this before gnulib-tool.
    echo "$0: $AUTOPOINT --force"
    $AUTOPOINT --force || exit
  fi

  # Autoreconf runs aclocal before libtoolize, which causes spurious
  # warnings if the initial aclocal is confused by the libtoolized
  # (or worse out-of-date) macro directory.
  # libtoolize 1.9b added the --install option; but we support back
  # to libtoolize 1.5.22, where the install action was default.
  if test $use_libtool = 1; then
    install=
    case $($LIBTOOLIZE --help) in
      *--install*) install=--install ;;
    esac
    echo "running: $LIBTOOLIZE $install --copy"
    $LIBTOOLIZE $install --copy
  fi

  find . ! -type d -print | sort >$tempbase.1
  old_IFS=$IFS
  IFS=$nl
  for file in $(comm -13 $tempbase.0 $tempbase.1); do
    IFS=$old_IFS
    parent=${file%/*}
    version_controlled_file "$parent" "$file" || {
      for dot_ig in x $vc_ignore; do
        test $dot_ig = x && continue
        ig=$parent/$dot_ig
        insert_vc_ignore "$ig" "${file##*/}"
      done
    }
  done
  IFS=$old_IFS

  rm -f $tempbase.0 $tempbase.1
  trap - 1 2 13 15
fi

# Import from gnulib.

gnulib_tool_options="\
 --import\
 --no-changelog\
 --aux-dir $build_aux\
 --doc-base $doc_base\
 --lib $gnulib_name\
 --m4-base $m4_base/\
 --source-base $source_base/\
 --tests-base $tests_base\
 --local-dir $local_gl_dir\
 $gnulib_tool_option_extras\
"
if test $use_libtool = 1; then
  case "$gnulib_tool_options " in
    *' --libtool '*) ;;
    *) gnulib_tool_options="$gnulib_tool_options --libtool" ;;
  esac
fi
echo "$0: $gnulib_tool $gnulib_tool_options --import ..."
$gnulib_tool $gnulib_tool_options --import $gnulib_modules \
  || die "gnulib-tool failed"

for file in $gnulib_files; do
  symlink_to_dir "$GNULIB_SRCDIR" $file \
    || die "failed to symlink $file"
done

bootstrap_post_import_hook \
  || die "bootstrap_post_import_hook failed"

# Remove any dangling symlink matching "*.m4" or "*.[ch]" in some
# gnulib-populated directories.  Such .m4 files would cause aclocal to fail.
# The following requires GNU find 4.2.3 or newer.  Considering the usual
# portability constraints of this script, that may seem a very demanding
# requirement, but it should be ok.  Ignore any failure, which is fine,
# since this is only a convenience to help developers avoid the relatively
# unusual case in which a symlinked-to .m4 file is git-removed from gnulib
# between successive runs of this script.
find "$m4_base" "$source_base" \
  -depth \( -name '*.m4' -o -name '*.[ch]' \) \
  -type l -xtype l -delete > /dev/null 2>&1

# Invoke autoreconf with --force --install to ensure upgrades of tools
# such as ylwrap.
AUTORECONFFLAGS="--verbose --install --force -I $m4_base $ACLOCAL_FLAGS"

# Some systems (RHEL 5) are using ancient autotools, for which the
# --no-recursive option had not been invented.  Detect that lack and
# omit the option when it's not supported.  FIXME in 2017: remove this
# hack when RHEL 5 autotools are updated, or when they become irrelevant.
case $($AUTORECONF --help) in
  *--no-recursive*) AUTORECONFFLAGS="$AUTORECONFFLAGS --no-recursive";;
esac

# Tell autoreconf not to invoke autopoint or libtoolize; they were run above.
echo "running: AUTOPOINT=true LIBTOOLIZE=true $AUTORECONF $AUTORECONFFLAGS"
AUTOPOINT=true LIBTOOLIZE=true $AUTORECONF $AUTORECONFFLAGS \
  || die "autoreconf failed"

# Get some extra files from gnulib, overriding existing files.
for file in $gnulib_extra_files; do
  case $file in
  */INSTALL) dst=INSTALL;;
  build-aux/*) dst=$build_aux/${file#build-aux/};;
  *) dst=$file;;
  esac
  symlink_to_dir "$GNULIB_SRCDIR" $file $dst \
    || die "failed to symlink $file"
done

if test $with_gettext = yes; then
  # Create gettext configuration.
  echo "$0: Creating po/Makevars from po/Makevars.template ..."
  rm -f po/Makevars
  sed '
    /^EXTRA_LOCALE_CATEGORIES *=/s/=.*/= '"$EXTRA_LOCALE_CATEGORIES"'/
    /^COPYRIGHT_HOLDER *=/s/=.*/= '"$COPYRIGHT_HOLDER"'/
    /^MSGID_BUGS_ADDRESS *=/s|=.*|= '"$MSGID_BUGS_ADDRESS"'|
    /^XGETTEXT_OPTIONS *=/{
      s/$/ \\/
      a\
          '"$XGETTEXT_OPTIONS"' $${end_of_xgettext_options+}
    }
  ' po/Makevars.template >po/Makevars \
    || die 'cannot generate po/Makevars'

  # If the 'gettext' module is in use, grab the latest Makefile.in.in.
  # If only the 'gettext-h' module is in use, assume autopoint already
  # put the correct version of this file into place.
  case $gnulib_modules in
  *gettext-h*) ;;
  *gettext*)
    cp $GNULIB_SRCDIR/build-aux/po/Makefile.in.in po/Makefile.in.in \
      || die "cannot create po/Makefile.in.in"
    ;;
  esac

  if test -d runtime-po; then
    # Similarly for runtime-po/Makevars, but not quite the same.
    rm -f runtime-po/Makevars
    sed '
      /^DOMAIN *=.*/s/=.*/= '"$package"'-runtime/
      /^subdir *=.*/s/=.*/= runtime-po/
      /^MSGID_BUGS_ADDRESS *=/s/=.*/= bug-'"$package"'@gnu.org/
      /^XGETTEXT_OPTIONS *=/{
        s/$/ \\/
        a\
            '"$XGETTEXT_OPTIONS_RUNTIME"' $${end_of_xgettext_options+}
      }
    ' po/Makevars.template >runtime-po/Makevars \
    || die 'cannot generate runtime-po/Makevars'

    # Copy identical files from po to runtime-po.
    (cd po && cp -p Makefile.in.in *-quot *.header *.sed *.sin ../runtime-po)
  fi
fi

bootstrap_epilogue

echo "$0: done.  Now you can run './configure'."

# Local variables:
# eval: (add-hook 'write-file-hooks 'time-stamp)
# time-stamp-start: "scriptversion="
# time-stamp-format: "%:y-%02m-%02d.%02H"
# time-stamp-time-zone: "UTC0"
# time-stamp-end: "; # UTC"
# End: