#!/bin/bash

set -ef -o pipefail

scripts=$(dirname $0)
. $scripts/jenkins-helpers.sh

convert_args_to_variables "$@"

# Execution mode: baseline, bisect, continue, jenkins-full
mode="${mode-baseline}"

obligatory_variables toolchain \
		     rr[linux_version] rr[linux_url] rr[linux_branch]

# Toolchain to use: gnu or llvm
case "$toolchain" in
    "gnu") obligatory_variables rr[gnu_version] \
				rr[binutils_url] rr[binutils_branch] \
				rr[gcc_url] rr[gcc_branch] ;;
    "llvm") obligatory_variables rr[llvm_version] \
				 rr[llvm_url] rr[llvm_branch] ;;
esac

case "$mode" in
    "jenkins-full")
	obligatory_variables current_project current_branch
	;;
esac

# Set custom revision for one of the projects, and use baseline revisions
# for all other projects.
current_project="${current_project-none}"
current_branch="${current_branch-default}"

linux_config="${linux_config-defconfig}"
reset_baseline="${reset_baseline-false}"
start_at="${start_at-default}"
finish_at="${finish_at-default}"
target="${target-native}"
top_artifacts="${top_artifacts-$(pwd)/artifacts}"
verbose="${verbose-true}"
verbose2="${verbose2-false}"

set -u

if $verbose2; then set -x; fi

trap "eval \"echo ERROR at \${FUNCNAME[0]}:\${BASH_LINENO[0]}\" > $top_artifacts/failures" EXIT

if [ x"$target" = x"native" ]; then
    target=$(uname -m)
fi

# Set start and finish steps for different modes.
default_start_at=""
default_finish_at=""
case "$mode" in
    "baseline")
	default_finish_at="update_baseline"
	;;
    "bisect")
	case "$toolchain:$current_project" in
	    gnu:binutils) default_start_at="build_abe-binutils" ;;
	    gnu:gcc) default_start_at="build_abe-stage1" ;;
	    gnu:linux) default_start_at="count_linux_objs" ;;
	    llvm:llvm) default_start_at="build_llvm" ;;
	    llvm:linux) default_start_at="count_linux_objs" ;;
	esac
	default_finish_at="check_regression"
	;;
    "continue")
	# Developer mode.
	case "$toolchain" in
	    "gnu") default_start_at="prepare_abe" ;;
	    "llvm") default_start_at="build_llvm" ;;
	esac
	;;
    "jenkins-full") ;;
esac

if [ x"$start_at" = x"default" ]; then
    start_at="$default_start_at"
fi
if [ x"$finish_at" = x"default" ]; then
    finish_at="$default_finish_at"
fi

if [ x"$mode" != x"continue" ]; then
    base_artifacts_opt="base-artifacts"
else
    base_artifacts_opt=""
fi

run_step_init "$start_at" "$finish_at" "$top_artifacts" "$base_artifacts_opt" "$verbose"

rr[baseline_branch]="linaro-local/ci/tcwg_kernel/$toolchain-${rr[${toolchain}_version]}-$target-${rr[linux_version]}-$linux_config"
rr[current_project]="$current_project"
rr[current_branch]="$current_branch"
rr[mode]="$mode"
rr[reset_baseline]="$reset_baseline"
rr[target]="$target"
rr[top_artifacts]="$top_artifacts"

# Linux config to build in build_linux.
rr[linux_config]="$linux_config"

# Toolchain to use: gnu or llvm.
rr[toolchain]="$toolchain"

. $scripts/round-robin.sh

# Build Linux kernel
build_linux ()
{
    (
    set -euf -o pipefail

    clone_repo linux

    rm -rf $(pwd)/bin
    mkdir $(pwd)/bin

    local bin cc

    case "${rr[toolchain]}" in
	llvm)
	    bin="$(pwd)/llvm-install/bin"
	    cc="$bin/clang"
	    ;;
	gnu)
	    bin="$(pwd)/abe/builds/destdir/x86_64-unknown-linux-gnu/bin"
	    cc="$bin/$(print_gnu_target ${rr[target]})-gcc"
	    ;;
    esac

    # Use binutils, etc from $bin
    export PATH="$bin:$PATH"

    # Use ccache only when bisecting linux (or preparing to).
    # Otherwise the compiler is new in every build and we would
    # only clobber ccache volume.
    local ccache=""
    if [ x"${rr[mode]}" != x"jenkins-full" -a x"${rr[current_project]}" = x"linux" ]; then
	ccache="ccache"
    fi
    cat > $(pwd)/bin/${rr[target]}-cc <<EOF
#!/bin/sh
exec $ccache $cc "\$@"
EOF
    chmod +x $(pwd)/bin/${rr[target]}-cc

    # Define make variables.
    local opts="CC=$(pwd)/bin/${rr[target]}-cc SUBLEVEL=0 EXTRAVERSION=-bisect"
    if [ x"${rr[target]}" != x"$(uname -m)" ]; then
	opts="$opts ARCH=$(print_kernel_target ${rr[target]})"
	opts="$opts CROSS_COMPILE=$(print_gnu_target ${rr[target]})-"
	opts="$opts HOSTCC=gcc"
    fi

    cd linux

    make $opts distclean

    make $opts ${rr[linux_config]}
    sed -i -e 's:CONFIG_LOCALVERSION_AUTO=y:# CONFIG_LOCALVERSION_AUTO is not set:' .config
    set +f; rm -f localversion*; set -f
    make $opts oldconfig

    ccache -z
    KBUILD_BUILD_TIMESTAMP=0 make $opts -j$(nproc --all) -s -k &
    local res=0 && wait $! || res=$?
    ccache -s
    cp include/config/kernel.release $run_step_artifacts/
    return $res
    )
}

# Count number successfully built .o files in linux (and build linux)
count_linux_objs ()
{
    (
    set -euf -o pipefail

    if true; then
	build_linux &
	local res=0; wait $! || res=$?

	# Number of .o files created is the main success metric.
	echo "linux_n_obj:" >> ${rr[top_artifacts]}/results
	if [ $res != 0 ]; then
	    local linux_n_obj
	    linux_n_obj=$(find linux -name "*.o" | wc -l)
	    echo "$linux_n_obj" >> ${rr[top_artifacts]}/results
	else
	    echo "all" >> ${rr[top_artifacts]}/results
	fi
    fi
    )
}


# Exit with code 0 if no regression compared to base-artifacts/results.
no_regression_p ()
{
    (
    set -euf -o pipefail

    local linux_n_obj
    linux_n_obj=$(tail -n1 ${rr[top_artifacts]}/results)

    if [ x"$linux_n_obj" = x"all" ]; then
	# Ideal result, no need to compare to baseline.
	return 0
    fi

    if ! [ "$linux_n_obj" -ge "-10" ]; then
	# Something is very wrong with result (e.g., it's not a number).
	return 1
    fi

    # Assume worst for non-existent baseline.
    local base_linux_n_obj="-10"

    if [ -f base-artifacts/results ]; then
	base_linux_n_obj=$(tail -n1 base-artifacts/results)
	if [ x"$base_linux_n_obj" = x"all" ]; then
	    # Current build is not ideal, so make sure baseline "all" is
	    # better than the current result.
	    base_linux_n_obj=$(($linux_n_obj+1))
	elif ! [ "$base_linux_n_obj" -ge "-10" ]; then
	    # Something is very wrong with baseline result
	    # (e.g., it's not a number).
	    return 0
	fi
    fi

    if [ $linux_n_obj -ge $base_linux_n_obj ]; then
	return 0
    else
	return 1
    fi
    )
}

run_step stop_on_fail -10 reset_artifacts
case "${rr[toolchain]}" in
    gnu)
	run_step stop_on_fail x prepare_abe
	run_step skip_on_fail -9 build_abe binutils
	run_step skip_on_fail -8 build_abe stage1
	;;
    llvm)
	run_step skip_on_fail -1 build_llvm
	;;
esac
run_step skip_on_fail x count_linux_objs
run_step reset_on_fail x check_regression
run_step stop_on_fail x update_baseline
run_step stop_on_fail x push_baseline

trap "" EXIT