#!/bin/bash

#

# Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.

# DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

#

# This code is free software; you can redistribute it and/or modify it

# under the terms of the GNU General Public License version 2 only, as

# published by the Free Software Foundation.

#

# This code 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

# version 2 for more details (a copy is included in the LICENSE file that

# accompanied this code).

#

# You should have received a copy of the GNU General Public License version

# 2 along with this work; if not, write to the Free Software Foundation,

# Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

#

# Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

# or visit www.oracle.com if you need additional information or have any

# questions.

#

# Simple tool to diff two shared libraries. 

# Criterias: two shared libraries are considered equal if:

# the file sizes are the same AND the symbols outputs from the nm command are equal

if [ $# -lt 2 ] 

then

  echo "Diff two shared libs. Return codes:"

  echo "0 - no diff"

  echo "1 - Identical symbols AND size, BUT not bytewise identical"

  echo "2 - Identical symbols BUT NEW size"

  echo "3 - Differences, content BUT SAME size"

  echo "4 - Differences, content AND size"

  echo "10 - Could not perform diff"

  echo "Use 'quiet' to disable any output."

  echo "Syntax: $0 file1 file2 [quiet]"

  exit 10

fi

if [ ! -f $1 ]

then

  echo $1 does not exist

  exit 10

fi

if [ ! -f $2 ]

then

  echo $2 does not exist

  exit 10

fi

if [ "`uname`" == "SunOS" ]; then

    NM=gnm

    STAT=gstat

elif [ $OSTYPE == "cygwin" ]; then

    NM="$VS100COMNTOOLS/../../VC/bin/amd64/dumpbin.exe"

    NM_ARGS=/exports

    STAT=stat

else

    NM=nm

    STAT=stat

fi

# Should the differences be viewed?

VIEW=

# You can do export DIFF=meld to view

# any differences using meld instead.

if [ -n "$DIFF" ]; then

    DIFF="$DIFF"

else

    DIFF=diff

fi

OLD=$(cd $(dirname $1) && pwd)/$(basename $1)

NEW=$(cd $(dirname $2) && pwd)/$(basename $2)

OLD_SIZE=$($STAT -c%s "$OLD")

NEW_SIZE=$($STAT -c%s "$NEW")

if [ $# -gt 3 ]

then

    ROOT1=$(cd $3 && pwd)

    ROOT2=$(cd $4 && pwd)

    OLD_NAME=$(echo $OLD | sed "s|$ROOT1/||")

    NEW_NAME=$(echo $NEW | sed "s|$ROOT2/||")

    if [ "x$5" == "xview" ]; then VIEW=view; fi

else

    ROOT1=$(dirname $OLD)/

    ROOT2=$(dirname $NEW)/

    OLD_NAME=$OLD

    NEW_NAME=$NEW

    if [ "x$3" == "xview" ]; then VIEW=view; fi

fi

OLD_SUFFIX="${OLD##*.}"

NEW_SUFFIX="${NEW##*.}"

if [ "$OLD_SUFFIX" != "$NEW_SUFFIX" ]; then

    echo The files do not have the same suffix type!

    exit 10

fi

if [ "$OLD_SUFFIX" != "so" ] && [ "$OLD_SUFFIX" != "dylib" ] && [ "$OLD_SUFFIX" != "dll" ]; then

    echo The files have to be .so, .dylib or .dll! They are $OLD_SUFFIX

    exit 10

fi

TYPE="$OLD_SUFFIX"

if cmp $OLD $NEW > /dev/null

then

    # The files were bytewise identical.

    echo Identical: $OLD_NAME

    exit 0

fi

OLD_SYMBOLS=$COMPARE_ROOT/$OLD_NAME.old

NEW_SYMBOLS=$COMPARE_ROOT/$NEW_NAME.new

mkdir -p $(dirname $OLD_SYMBOLS)

mkdir -p $(dirname $NEW_SYMBOLS)

if [ $OSTYPE == "cygwin" ]; then

    "$NM" $NM_ARGS $OLD | grep " = " > $OLD_SYMBOLS

    "$NM" $NM_ARGS $NEW | grep " = " > $NEW_SYMBOLS

    "$NM" $NM_ARGS $OLD > $OLD_SYMBOLS.full

    "$NM" $NM_ARGS $NEW > $NEW_SYMBOLS.full

else

    # Strip the addresses, just compare the ordering of the symbols.

    $NM $OLD | cut -f 2- -d ' ' > $OLD_SYMBOLS

    $NM $NEW | cut -f 2- -d ' ' > $NEW_SYMBOLS

    # But store the full information for easy diff access.

    $NM $OLD  > $OLD_SYMBOLS.full

    $NM $NEW  > $NEW_SYMBOLS.full

fi

DIFFS=$(LANG=C diff $OLD_SYMBOLS $NEW_SYMBOLS)

RESULT=0

if [ -n "$DIFFS" ]; then

   if [ $OLD_SIZE -ne $NEW_SIZE ]

   then

       echo Differences, content AND size     : $OLD_NAME 

       RESULT=4

   else

       echo Differences, content BUT SAME size: $OLD_NAME 

       RESULT=3

   fi

   if [ "x$VIEW" == "xview" ]; then

       LANG=C $DIFF $OLD_SYMBOLS $NEW_SYMBOLS

   fi

else

   if [ $OLD_SIZE -ne $NEW_SIZE ]

   then

       echo Identical symbols BUT NEW size    : $OLD_NAME 

       RESULT=2

   else

       echo Identical symbols AND size, BUT not bytewise identical: $OLD_NAME 

       RESULT=1

   fi

fi

exit $RESULT