#!/usr/bin/python3
#
# 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:
#
# 2018/06/01 - Update for python3 by Petr Oros.
# 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 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, *ns = in_line.split()
        ns = ns[0] if ns else None

        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, *ns = in_line.split()
        ns = ns[0] if ns else None

        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 = []
    ns_symbols = []

    for symbol in kabi:
        abi_hash, abi_sym, abi_dir, abi_type, *abi_ns = kabi[symbol].split()
        abi_ns = abi_ns[0] if abi_ns else None
        if symbol in symvers:
            sym_hash, sym_sym, sym_dir, sym_type, *sym_ns = symvers[symbol].split()
            sym_ns = sym_ns[0] if sym_ns else None
            if abi_hash != sym_hash:
                fail = 1
                changed_symbols.append(symbol)

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

            if abi_ns != sym_ns:
                warn = 1
                ns_symbols.append(symbol)
        else:
            fail = 1
            changed_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("")
        for symbol in changed_symbols:
            print(symbol)
        print("")

    if warn:
        print("*** WARNING - ABI SYMBOLS MOVED ***")
        if moved_symbols:
            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(symbol)
            print("")
        if ns_symbols:
            print("")
            print("The following symbols changed symbol namespaces:")
            print("")
            for symbol in ns_symbols:
                print(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:
        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)