#!/usr/bin/python
#
# check-kabi - Red Hat kABI reference checking tool
#
# We use this script to check against reference Module.kabi files.
#
# Author: Jon Masters <jcm@redhat.com>
# Copyright (C) 2007-2009 Red Hat, Inc.
#
# This software may be freely redistributed under the terms of the GNU
# General Public License (GPL).

# Changelog:
# 
# 2009/08/15 - Updated for use in RHEL6.
# 2007/06/13 - Initial rewrite in python by Jon Masters.

__author__ = "Jon Masters <jcm@redhat.com>"
__version__ = "2.0"
__date__ = "2009/08/15"
__copyright__ = "Copyright (C) 2007-2009 Red Hat, Inc"
__license__ = "GPL"

import getopt
import os
import re
import string
import sys

true = 1
false = 0

def load_symvers(symvers,filename):
	"""Load a Module.symvers file."""

	symvers_file = open(filename,"r")

	while true:
		in_line = symvers_file.readline()
		if in_line == "":
			break
		if in_line == "\n":
			continue
		checksum,symbol,directory,type = in_line.split()

		symvers[symbol] = in_line[0:-1]

def load_kabi(kabi,filename):
	"""Load a Module.kabi file."""

	kabi_file = open(filename,"r")

	while true:
		in_line = kabi_file.readline()
		if in_line == "":
			break
		if in_line == "\n":
			continue
		checksum,symbol,directory,type = in_line.split()

		kabi[symbol] = in_line[0:-1]

def check_kabi(symvers,kabi):
	"""Check Module.kabi and Module.symvers files."""

	fail=0
	warn=0
	lost=0
	changed_symbols=[]
	moved_symbols=[]
	losted_symbols=[]

	for symbol in kabi:
		abi_hash,abi_sym,abi_dir,abi_type = kabi[symbol].split()
		if symbol in symvers:
			sym_hash,sym_sym,sym_dir,sym_type = symvers[symbole].split()
			if abi_hash != sym_hash:
				fail=1
				changed_symbols.append(symbol)

			if abi_dir != sym_dir:
				warn=1
				moved_symbols.append(symbol)
		else:
			lost=1
			losted_symbols.append(symbol)

	if fail:
		print ("*** ERROR - ABI BREAKAGE WAS DETECTED ***")
		print ("")
		print ("The following symbols have been changed (this will cause an ABI breakage):")
		print ("new kabi:")
		for symbol in changed_symbols:
			print (symvers[symbol])
		print ("old kabi:")
		for symbol in changed_symbols:
			print (kabi[symbol])
		print ("")

	if lost:
		print ("*** ERROR - ABI BREAKAGE WAS DETECTED ***")
		print ("")
		print ("The following symbols have been losted (this will cause an ABI breakage):")
		print ("old kabi:")
		for symbol in losted_symbols:
			print (kabi[symbol])
		print ("")

	if warn:
		print ("*** WARNING - ABI SYMBOLS MOVED ***")
		print ("")
		print ("The following symbols moved (typically caused by moving a symbol from being")
		print ("provided by the kernel vmlinux out to a loadable module):")
		print ("new kabi:")
		for symbol in moved_symbols:
			print (symvers[symbol])
		print ("old kabi")
		for symbol in moved_symbols:
			print (kabi[symbol])

		print ("")

	"""Halt the build, if we got errors and/or warnings. In either case,
	   double-checkig is required to avoid introducing / concealing
	   KABI inconsistencies."""
	if fail or warn or lost:
		sys.exit(1)
	sys.exit(0)

def usage():
	print ("""
check-kabi: check Module.kabi and Module.symvers files.

	check-kabi [ -k Module.kabi ] [ -s Module.symvers ]

""")

if __name__ == "__main__":

	symvers_file = ""
	kabi_file = ""

	opts, args = getopt.getopt(sys.argv[1:], 'hk:s:')

	for o, v in opts:
		if o == "-s":
			symvers_file = v
		if o == "-h":
			usage()
			sys.exit(0)
		if o == "-k":
			kabi_file = v
	
	if (symvers_file == "") or (kabi_file == ""):
		usage()
		sys.exit(1)

	symvers={}
	kabi={}

	load_symvers(symvers,symvers_file)
	load_kabi(kabi,kabi_file)
	check_kabi(symvers,kabi)