#! /bin/bash

#############################################################################

# Copyright (c) 2007 Novell, Inc.

# All Rights Reserved.

#

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

# modify it under the terms of version 2 of the GNU General Public License as

# published by the Free Software Foundation.

#

# 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, contact Novell, Inc.

#

# To contact Novell about this file by physical or electronic mail,

# you may find current contact information at www.novell.com

#############################################################################

# The symtypes file format is as follows:

#

#  * Each object file has its own, independent section in the symtypes file.

#    Except to avoid repeated identical definitions as explained later, each

#    of these sections is independent.

#

#  * Lines starting with x# are definitions of types that are used later.

#    Only definitions that are actually used show up in the dump. Lines not

#    starting with x# indicate an exported symbol, e.g.,

#

#    t#u32 typedef unsigned int u32

#    acpi_register_gsi int acpi_register_gsi (t#u32, int, int)

#

#  * To keep the dumps reasonably small, identical definitions are not

#    repeated. Instead, only the fact that a symbols is being defined is noted.

#    So instead of the full t#u32 definition from above, only "t#u32" appears

#    after the first definition. If a type is defined differently in different

#    places, the full definitions are given.

#

#

# The checksums are computed taking into consideration all the definitions

# known, recursively. For example, wherever struct acpi_processor_tx is used,

# the defintions of typedef u16 as well as struct acpi_processor_tx define

# the result:

#

#    t#u16 typedef unsigned short u16

#    s#acpi_processor_tx struct acpi_processor_tx {t#u16 power;

#                                                  t#u16 performance}

#

# Forward declarations are a problem: if a symbol only has been forward

# declared it may be used, but the checksum will not include its definition.

# If the symbols's definition later becomes known before the symbol is used,

# this will change the checksum even if the actual types did not change.

# This is an unsolved problem.

if [ $# -ne 2 ]; then

    echo "Usage: ${0##*/} <symtypes1.gz> <symtypes2.gz>"

    echo "Show the differences between two /boot/symtypes-*.gz files."

    exit

fi

verbose_symtypes() {

    # The symtypes dumps have repeated identical type definitions stripped out.

    # Fill in the stripped-out definition to make the diff easier to understand.

    gzip -df < "$1" \

    | awk '

	$1 ~ /^.#.*/ {

	    if (NF != 1)

		syms[$1] = $0;

	    print syms[$1];

	    next;

	}

	{ print }

    '

}

diff -U0 --show-function-line='^/\*' --label "$1" --label "$2" \

    <(verbose_symtypes "$1") <(verbose_symtypes "$2")