#!/usr/bin/env bash

set -o nounset
set -o errexit
set -o errtrace

ktest_dir=$(dirname "$(readlink -f "$0")")
KTEST=$ktest_dir/ktest

. "$ktest_dir/lib/libktest.sh"

checkdep gcc
checkdep clang
checkdep make
checkdep bison
checkdep flex
checkdep bc

ktest_njobs=$(nproc)
ktest_precise=false
ktest_compiler="${CC:-gcc}"
ktest_skip_kernel_config=false

COVERAGE=""		# doing code coverage?
MAKEARGS=()
DEPMOD=depmod

if ! which depmod > /dev/null; then
    DEPMOD=/sbin/depmod
fi

usage()
{
    echo "build-test-kernel: Run generic virtual machine tests"
    echo "Usage: build-test-kernel cmd [options]"
    ktest_usage_cmds
    echo "  oldconfig           Run make oldconfig"
    echo "  config              Run make nconfig"
    echo
    echo "  options:"
    ktest_usage_opts
    echo
    echo " options for build-test-kernel run:"
    ktest_usage_run_opts
    echo "      -k <dir>        kernel source dir"
    echo "      -c <dir>        enable coverage for this dir (only valid without -K)"
    echo "      -M <arg>        extra arguments to be passed to make when building the kernel"
    echo "      -K              keep existing kernel .config"
    echo
    ktest_usage_post
}

if [[ $# = 0 ]]; then
    usage
    exit 1
fi

#parse command and shift for rest of arg parsing
CMD="$1"
shift

while getopts "k:Pc:M:Kh${ktest_args}" arg; do
    case $arg in
	k)
	    ktest_kernel_source="$OPTARG"
	    ;;
	P)
	    ktest_precise=true
	    ;;
	c)
	    if [[ ! -d $OPTARG ]]; then
		echo "$OPTARG must be a directory"
		exit 1
	    fi

	    checkdep lcov

	    # Strip trailing / from directory name, substitute _ for /
	    OPTARG=$(echo "${OPTARG%/}"|tr / _)
	    MAKEARGS+=("GCOV_PROFILE_$OPTARG=y")
	    COVERAGE=1
	    ;;
	M)
	    MAKEARGS+=("$OPTARG")
	    ;;
	K)
	    ktest_skip_kernel_config=true
	    ;;
	h)
	    usage
	    exit 0
	    ;;
    esac
    parse_ktest_arg $arg
done
shift $(( OPTIND - 1 ))

parse_args_post

# default parameters
[[ -z $ktest_kernel_source ]]	&& ktest_kernel_source="."

if [[ ! -d $ktest_kernel_source ]]; then
    echo "kernel source directory $ktest_kernel_source does not exist"
    exit 1
fi

ktest_kernel_source=$(readlink -e "$ktest_kernel_source")

ktest_kernel_build="$ktest_out/kernel_build.$ktest_arch"
mkdir -p "$ktest_kernel_build"

if [[ -n $CROSS_COMPILE ]]; then
    checkdep "$ARCH_TRIPLE-gcc" "gcc-$ARCH_TRIPLE"
fi

run_ktest()
{
    arg=$1
    shift

    "$KTEST" "$arg" $KTESTARGS "$@"
}

map_clang_version() {
    case "$ktest_compiler" in
        clang) echo "1" ;;
        clang-[0-9]*) echo "-${ktest_compiler#clang-}" ;;
        *) echo "" ;;
    esac
}

do_make()
{
    if [[ -n $CROSS_COMPILE ]]; then
	export ARCH="$KERNEL_ARCH"
	export CROSS_COMPILE="$ARCH_TRIPLE-"
    fi

    make --jobs="$ktest_njobs"			\
	--directory="$ktest_kernel_source"    	\
	CC="$ktest_compiler"			\
	LLVM="$(map_clang_version)"		\
	O="$ktest_kernel_build"			\
	INSTALL_MOD_PATH="$ktest_kernel_binary"	\
	"${ktest_kernel_make_append[@]}"	\
	"${MAKEARGS[@]}"			\
	"$@"
}

new_config()
{
    local kconfig="$ktest_kernel_build/.config"
    local config_tool="$ktest_kernel_source/scripts/config"

    if [[ ! -f $kconfig ]]; then
	do_make allnoconfig

	# Really undefine everything:
	sed -i -e 's/\(CONFIG_.*\)=.*/# \1 is not set/' "$kconfig"
    fi
}

kernel_opt()
{
    local cmd=$1
    local opt=$2
    local kconfig="$ktest_kernel_build/.config"
    local config_tool="$ktest_kernel_source/scripts/config"
    local val=y
    local ret=0

    if [[ $opt =~ = ]]; then
	local val=${opt#*=}
	opt="${opt%=*}"
    fi

    case $cmd in
	set)
	    "$config_tool" --file "$kconfig" --set-val "$opt" "$val"
	    ;;
	check)
	    local c=$("$config_tool" --file "$kconfig" -s "$opt")

	    [[ $c = undef ]] && c=n

	    if [[ $c != $val ]]; then
		echo "Kernel config option $opt is $c; should be $val"

		# If the current kernel doesn't have the option available,
		# don't fail
		if [[ $(cd $ktest_kernel_source; git grep "CONFIG_$opt") ]]; then
		    ret=1
		fi
	    fi
	    ;;
    esac

    if [[ $ret != 0 ]]; then
	return $ret
    fi
}

configure_kernel()
{
    local kconfig="$ktest_kernel_build/.config"

    if [[ -f "$kconfig" ]]; then
	cp "$kconfig" "$kconfig".bak
    fi

    if [[ -z $ktest_kconfig_base ]]; then
	if $ktest_precise; then
	    rm -f "$kconfig"
	fi

	new_config
    else
	cp "$ktest_kconfig_base" "$kconfig"
    fi

    log_verbose "kernel_config_require: ${ktest_kernel_config_require[@]}  ${ktest_kernel_config_require_soft[@]}"

    MAKEARGS+=("LOCALVERSION=-ktest")

    for opt in "${ktest_kernel_config_require[@]}"; do
	[[ -n $opt ]] && kernel_opt set "$opt"
    done

    for opt in "${ktest_kernel_config_require_soft[@]}"; do
	[[ -n $opt ]] && kernel_opt set "$opt"
    done

    do_make olddefconfig

    for opt in "${ktest_kernel_config_require[@]}"; do
	[[ -n $opt ]] && kernel_opt check "$opt"
    done

    # Preserve timestamp if config didn't change:
    if [[ -f "$kconfig".bak ]] && diff -q "$kconfig" "$kconfig".bak; then
	mv "$kconfig".bak "$kconfig"
    fi
}

build_kernel()
{
    rm -rf "$ktest_kernel_binary"
    mkdir -p "$ktest_kernel_binary"

    if ! $ktest_skip_kernel_config; then
	configure_kernel
    fi

    case $KERNEL_ARCH in
	mips)
	    do_make -k vmlinuz
	    ;;
	*)
	    do_make -k
	    ;;
    esac

    local BOOT=$ktest_kernel_build/arch/$KERNEL_ARCH/boot

    case $ktest_arch in
	x86*)
	    install -m0644 "$BOOT/bzImage"	"$ktest_kernel_binary/vmlinuz"
	    ;;
	aarch64)
	    install -m0644 "$BOOT/Image"	"$ktest_kernel_binary/vmlinuz"
	    ;;
	mips)
	    install -m0644 "$BOOT/vmlinux.strip"	"$ktest_kernel_binary/vmlinuz"
	    #install -m0644 "$ktest_kernel_build/vmlinux"	"$ktest_kernel_binary/vmlinuz"
	    ;;
	default)
	    echo "Don't know how to install kernel"
	    exit 1
	    ;;
    esac

    install -m0644 "$ktest_kernel_build/vmlinux" "$ktest_kernel_binary/vmlinux"
    install -m0644 "$ktest_kernel_build/.config" "$ktest_kernel_binary/config"

    # if there weren't actually any modules selected, make modules_install gets
    # confused:
    touch "$ktest_kernel_build/modules.order"
    touch "$ktest_kernel_build/modules.builtin"

    do_make modules_install

    local kernel_version=$(cat "$ktest_kernel_build/include/config/kernel.release")
    $DEPMOD -b "$ktest_kernel_binary/" -v $kernel_version
}

cmd_run()
{
    if [[ $# = 0 ]]; then
	echo "build-test-kernel: missing test"
	usage
	exit 1
    fi

    ktest_test=$(realpath "$1")
    shift
    ktest_testargs="$@"

    echo Running test $(basename "$ktest_test") on $(uname -n) at $(pwd)
    parse_test_deps "$ktest_test"

    if [[ -n $COVERAGE ]]; then
	ktest_kernel_config_require+=(GCOV_KERNEL)
    fi

    run_quiet "building kernel" build_kernel

    start_vm
}

cmd_boot()
{
    cmd_run "$ktest_dir/boot.ktest"
}

cmd_oldconfig()
{
    new_config
    do_make oldconfig
}

cmd_config()
{
    new_config
    do_make nconfig "$@"
}

cmd_faddr2line()
{
    ./scripts/faddr2line "$ktest_kernel_build/vmlinux" $@
}

cmd_help()
{
    usage
}

if [[ $(type -t "cmd_$CMD") == function ]]; then
    CMD="cmd_$CMD"
elif [[ $(type -t "ktest_$CMD") == function ]]; then
    CMD="ktest_$CMD"
else
    usage
    exit 1
fi

$CMD "$@"