#!/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 Red Hat, Inc.
#
# This software may be freely redistributed under the terms of the GNU
# General Public License (GPL).

# Changelog:
# 
# 2007/06/13 - Initial rewrite in python by Jon Masters.

#
# "make path/to/file.symtypes" will create a symtypes file for path/to/file.c to allow comparisons.
#

__author__ = "Jon Masters <jcm@redhat.com>"
__version__ = "1.0"
__date__ = "2007/06/13"
__copyright__ = "Copyright (C) 2007 Red Hat, Inc"
__license__ = "GPL"

import getopt
import os
import re
# import sha
import string
import sys

true = 1
false = 0

sed_output = False

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 = string.split(in_line)

		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 = string.split(in_line)

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

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

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

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

			if abi_dir != sym_dir:
				warn=1
				moved_symbols.append(symbol)
		else:
			if sed_output:
				print "\\,%s\t%s\t%s\t%s,d;" \
				      % (abi_hash, symbol, abi_dir, abi_type)
			else:
				print "%s not present in Module.symvers?" % symbol

	if fail:
		if not sed_output:
			print "*** ERROR - ABI BREAKAGE WAS DETECTED ***"
			print ""
			print "The following symbols have been changed (this will cause an ABI breakage):"
			print ""
		for symbol in changed_symbols:
			sym_hash,sym_sym,sym_dir,sym_type = string.split(symvers[symbol])
			abi_hash,abi_abi,abi_dir,abi_type = string.split(kabi[symbol])
			print "# %s" % symbol
			if sed_output:
				print "s,%s\t%s\t%s\t%s,%s\t%s\t%s\t%s,g;" \
				      % (abi_hash, symbol, abi_dir, abi_type,
					 sym_hash, symbol, sym_dir, sym_type)
		print ""

	if warn:
		if not sed_output:
			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 ""
		for symbol in moved_symbols:
			print "# %s %s -> %s" % (symbol,abi_dir,sym_dir)
			if sed_output:
				sym_hash,sym_sym,sym_dir,sym_type = string.split(symvers[symbol])
				abi_hash,abi_abi,abi_dir,abi_type = string.split(kabi[symbol])
				print "s,%s\t%s\t%s\t%s,%s\t%s\t%s\t%s,g;" \
				      % (abi_hash, symbol, abi_dir, abi_type,
					 sym_hash, symbol, sym_dir, sym_type)
		print ""

	if fail:
		sys.exit(1)
	else:
		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:S')

	for o, v in opts:
		if o == "-S":
			sed_output = True
		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)

