#!/bin/dash

#
# Copyright (c) 2003, 2005, 2006, 2008, 2011, 2012 Jason Tishler
#
# 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 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 <http://www.gnu.org/licenses/>.
#
# See the COPYING file for full license information.
#
# Written by Jason Tishler <jason@tishler.net>
#
# $Id$
#

# Define constants
tp1=${0%/*}
tp2=${tp1:-.}
PATH=$(cd $tp2 && pwd):/usr/bin:/bin

ProgramName=${0##*/}
ProgramOptions='48b:o:ps:tT:v'
DefaultBaseAddress=0x70000000
DefaultOffset=0
DefaultTouch=
DefaultNoDyn=
DefaultVerbose=
DefaultFileList=
DefaultSuffixes='dll|so|oct'

# Define functions
usage()
{
    echo "usage: ${ProgramName} [-b BaseAddress] [-o Offset] [-s DllSuffix] [-T FileList | -] [-4|-8] [-p] [-t] [-v]"
    exit 1
}

cleanup()
{
    rm -f "${TmpFile}" "${SortedFile}"
    exit ${ExitCode}
}

# Determine platform
Platform=`uname -s`
case $Platform in
 *MINGW*  | *mingw*  ) Platform=mingw  ;;
 *CYGWIN* | *cygwin* ) Platform=cygwin ;;
 *MSYS*   | *msys*   ) Platform=msys   ;;
 * )
    echo "Unsupported platform: $Platform" 1>&2
    exit 1
    ;;
esac

# On Cygwin, just call the _autorebase postinstall script
case $Platform in
  cygwin)
    if [ "$#" -gt 0 ]
    then
      echo "usage: ${ProgramName}"
      exit 1
    fi
    exec /etc/postinstall/0p_000_autorebase.dash
    ;;
  *)
    ;;
esac

# Set traps
trap cleanup 1 2 15

# Set defaults
BaseAddress=""
Offset="${DefaultOffset}"
Touch="${DefaultTouch}"
NoDyn="${DefaultNoDyn}"
Verbose="${DefaultVerbose}"
FileList="${DefaultFileList}"
Suffixes="${DefaultSuffixes}"
db_file_i386="/etc/rebase.db.i386"
db_file_x86_64="/etc/rebase.db.x86_64"
check_for_dash_only="yes"
case `uname -m` in
    i[3456]86)
	db_file="${db_file_i386}";
	Mach="-4"
	;;
    x86_64)
	Mach="-8"
	db_file="${db_file_x86_64}"
	;;
esac

# Parse command line arguments
while getopts "${ProgramOptions}" Option "$@"
do
    case "${Option}" in
    4)
	db_file="${db_file_i386}";
	Mach="-4"
	;;
    8)
	Mach="-8"
	db_file="${db_file_x86_64}"
	;;
    b)
	BaseAddress="${OPTARG}";;
    o)
	Offset="${OPTARG}";;
    p)
	check_for_dash_only="no";;
    s)
	Suffixes="${Suffixes}|${OPTARG}";;
    t)
    	Touch="-t";;
    T)
	FileList="${OPTARG}";;
    v)
	Verbose="-v";;
    \?)
	usage;;
    esac
done

# Verify only ash or dash processes are running
if [ "${check_for_dash_only}" != "no" ]
then
  ProcessResult=0
  /bin/ps -s | /bin/gawk '\
	# Count number of running ash or dash. \
	/\/bin\/(d)?ash(\.exe)?$/{ ash_cnt++; } \
	# Count number of ps and gawk. \
	/\/bin\/ps(\.exe)?$/{ cnt++; } \
	/\/bin\/gawk(\.exe)?$/{ cnt++; } \
	END{ \
	  # Uncomment for testing: \
	  # printf "TOTAL: %d CNT: %d ASH_CNT: %d\n", NR, cnt, ash_cnt; \
	  # Only one of ps and gawk each may run. \
	  if (cnt > 2) \
	    exit 0; \
	  # The total number of allowed processes is one less than the \
	  # number of input lines.  The extra line is the ps header output. \
	  if (NR - cnt - ash_cnt > 1) \
	    exit 0; \
	  # All is well. \
	  exit 1; \
	}'
  ProcessResult=$?
  if [ $ProcessResult -eq 0 -a -z "${RebaseDebug}" ]
  then
      echo "${ProgramName}: only ash or dash processes are allowed during rebasing"
      echo "    Exit all Cygwin processes and stop all Cygwin services."
      echo "    Execute ash (or dash) from Start/Run... or a cmd or command window."
      echo "    Execute '/bin/rebaseall' from ash (or dash)."
      exit 2
  fi
fi

# Check if rebase database already exists.
database_exists="no"
[ -f "${db_file}" ] && database_exists="yes"

# If BaseAddress has not been specified, and the rebase database doesn't exist
# yet, set BaseAddress to default.
if [ -z "${BaseAddress}" -a "${database_exists}" != "yes" ]
then
  BaseAddress=$DefaultBaseAddress
fi

# Set temp directory
TmpDir="${TMP:-${TEMP:-/tmp}}"

# Validate temp directory
if [ ! -d "$TmpDir" ]
then
    echo "$ProgramName: '$TmpDir' is not a directory"
    exit 2
fi
if [ ! -w "$TmpDir" ]
then
    echo "$ProgramName: '$TmpDir' is not writable"
    exit 2
fi

# Validate user supplied file list, if necessary
if [ -n "$FileList" -a ! -r "$FileList" -a "$FileList" != - ]
then
    echo "$ProgramName: '$FileList' is not readable"
    exit 2
fi

# Set temp file
SortedFile="$TmpDir/rebase.lst"
TmpFile="${SortedFile}.in"

# Create rebase list
for f in /bin /lib
do
  find $f -type f |
    grep -E "\.($Suffixes)\$" |
    sed -e '/\/msys-1\.0.*\.dll$/d' -e '/\/cygwin1\.dll$/d' \
	-e '/\/cyglsa.*\.dll$/d' -e '/\/d\?ash\.exe$/d' \
	-e '/\/rebase\.exe$/d' >>"$TmpFile"
done

# Append user supplied file list, if any
if [ -n "${FileList}" ]
then
    cat "${FileList}" >>"${TmpFile}"
fi

# Remove duplicates
sort -u "${TmpFile}" > "${SortedFile}"

if [ -z "${BaseAddress}" ]
then
  rebase "${Verbose}" "${Touch}" "${NoDyn}" -s "${Mach}" -T "${SortedFile}"
else
  rebase "${Verbose}" "${Touch}" "${NoDyn}" -s "${Mach}" -b "${BaseAddress}" -o "${Offset}" -T "${SortedFile}"
fi
ExitCode=$?

# Clean up
cleanup