#!/bin/bash

# Consistency checks for the system call list

# Copyright (C) 2017-2018 Free Software Foundation, Inc.

# This file is part of the GNU C Library.

#

# The GNU C Library is free software; you can redistribute it and/or

# modify it under the terms of the GNU Lesser General Public

# License as published by the Free Software Foundation; either

# version 2.1 of the License, or (at your option) any later version.

#

# The GNU C Library 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

# Lesser General Public License for more details.

#

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

# License along with the GNU C Library; if not, see

# <http://www.gnu.org/licenses/>.

export LC_ALL=C

set -e

set -o pipefail

if test $# != 4; then

    echo "error: wrong number of arguments: $#"

    exit 1

fi

macros="$1"

list_nr="$2"

list_sys="$3"

GAWK="$4"

linux_version="$("$GAWK" \

  '/#define LINUX_VERSION_CODE / {print $3}' < "$macros")"

glibc_linux_version="$("$GAWK" \

  '/#define __GLIBC_LINUX_VERSION_CODE / {print $3}' < "$macros")"

echo "info: LINUX_VERSION_CODE: $linux_version"

echo "info: __GLIBC_LINUX_VERSION_CODE: $glibc_linux_version"

# Ignore the subrelease in the comparison.

if test $(expr "$glibc_linux_version" / 256) \

        -lt $(expr "$linux_version" / 256); then

    echo "info: The kernel major/minor version is newer than the glibc version"

    kernel_newer=true

else

    kernel_newer=false

fi

echo

errors=0

# Use getpid as a system call which is expected to be always defined.

# alpha uses getxpid instead, so it is permitted as an alternative.

if ! grep -E -q '^getx?pid$' -- "$list_nr"; then

    echo "error: __NR_getpid not defined"

    errors=1

fi

if ! grep -E -q '^getx?pid$' -- "$list_sys"; then

    echo "error: SYS_getpid not defined"

    errors=1

fi

comm_1="$(mktemp)"

comm_2="$(mktemp)"

comm_result="$(mktemp)"

cleanup () {

    rm -f -- "$comm_1" "$comm_2" "$comm_result"

}

trap cleanup 0

sort -o "$comm_1" -- "$list_nr"

sort -o "$comm_2" -- "$list_sys"

# Check for missing SYS_* macros.

comm --check-order -2 -3 -- "$comm_1" "$comm_2" > "$comm_result"

if test -s "$comm_result"; then

    echo "error: These system calls need to be added to syscall-names.list:"

    cat -- "$comm_result"

    # This is only an error if our version is older than the kernel

    # version because we cannot predict future kernel development.

    if $kernel_newer; then

        echo

        echo "warning: This error has been ignored because the glibc"

        echo "warning: system call list is older than the kernel version."

    else

        errors=1

    fi

fi

# Check for additional SYS_* macros.

comm --check-order -1 -3 -- "$comm_1" "$comm_2" > "$comm_result"

if test -s "$comm_result"; then

    echo "error: The following system calls have unexpected SYS_* macros:"

    cat -- "$comm_result"

    errors=1

fi

exit "$errors"