#!/bin/bash
#
# linux kernel CROSS make wrapper
#
# It will download/unpack the cross tool chain if necessary,
# then invoke make with suitable options.
#
# It detects ARCH in 4 ways.
#
# - make.i386 # make it a symlink to this script
# - make.cross ARCH=i386
# - cd obj-i386; make.cross
# - export ARCH=i386; make.cross
#
# Specify compiler and version (default is gcc):
# - COMPILER=gcc-9.3.0 make.cross ARCH=arm64
# - COMPILER=clang make.cross ARCH=arm64
#
# Copyright (c) 2014, Intel Corporation.
# Author: Fengguang Wu <fengguang.wu@intel.com>
# Credit: Tony Breeds <tony@bakeyournoodle.com> for crosstool

COMPILER=${COMPILER:-"gcc"}

arch_list=(
	alpha
	arc
	arm
	arm64
	avr32
	blackfin
	c6x
	cris
	csky
	frv
	h8300
	hexagon
	i386
	ia64
	loongarch
	m32r
	m68k
	microblaze
	mips
	mn10300
	nios2
	openrisc
	parisc
	parisc64
	powerpc
	riscv
	s390
	score
	sh
	sh32
	sh64
	sparc
	sparc32
	sparc64
	tile
	tilegx
	tilepro
	um
	unicore32
	x86
	x86_64
	xtensa
)

if [[ ! "$0" =~ 'make.cross' && "$0" =~ make\.([a-z0-9_]+) ]]; then
	export ARCH="${BASH_REMATCH[1]}"
elif [[ "$*" =~ ARCH=([a-z0-9_]+) ]]; then
	export ARCH="${BASH_REMATCH[1]}"
elif [[ ${PWD##*-} =~ ^($(IFS=\| && echo "${arch_list[*]}"))$ ]]; then
	echo "ARCH set to ${PWD##*-}"
	export ARCH=${PWD##*-}
elif [[ ! $ARCH ]]; then
	export ARCH=x86_64
fi

[[ "$*" =~ ARCH=([a-z0-9_]+) ]] && [[ $ARCH != ${BASH_REMATCH[1]} ]] && {
	echo "Conflicting ARCH specified! $ARCH ${BASH_REMATCH[1]}"
	exit 1
}

if [[ "$*" =~ O=([^ ]+) ]]; then
	BUILD_DIR="${BASH_REMATCH[1]}"
elif [[ -n "$KBUILD_OUTPUT" ]]; then
	BUILD_DIR="$KBUILD_OUTOUT"
elif [[ -d obj-$ARCH ]]; then
	BUILD_DIR=obj-$ARCH
	O=O=obj-$ARCH
else
	BUILD_DIR="."
fi

shopt -s nullglob

is_clang_worker()
{
	[[ "$COMPILER" =~ "clang" ]]
}

check_install_path()
{
	if [[ $COMPILER_INSTALL_PATH ]]; then
		echo "Compiler will be installed in $COMPILER_INSTALL_PATH"
	else
		return 1
	fi

}

install_packages()
{
	local ret=0
	[[ -x /usr/bin/xz ]] || {
		echo Please install: xz-utils or xz
		ret=1
	}

	[[ -x /usr/bin/lftp ]] || {
		echo Please install: lftp
		ret=1
	}

	[[ -x /usr/bin/ldd ]] || {
		echo Please install: libc-bin
		ret=1
	}

	return $ret
}

install_dependence()
{
	local exec=$1
	local errors=$(ldd $exec | grep "not found")
	[[ $errors ]] || return 0

	echo "$errors" | grep -q "libc.so.6.*GLIBC_" && {
		echo Please update: libc6 or glibc
	}

	echo "ldd $exec"
	echo "$errors"
	return 1
}

download_extract()
{
	local URL="$1"
	local file="$(basename $URL)"
	local dir="$COMPILER_INSTALL_PATH/$(basename $(dirname $URL))"

	mkdir -p $COMPILER_INSTALL_PATH || {
		echo "Can't use $COMPILER_INSTALL_PATH as compiler install path, please choose a different COMPILER_INSTALL_PATH"
		return 1
	}

	mkdir -p $dir || return
	cd $dir || return

	echo lftpget -c $URL
	     lftpget -c $URL || return
	cd - || return

	echo tar Jxf $dir/$file -C $COMPILER_INSTALL_PATH
	tar Jxf $dir/$file -C $COMPILER_INSTALL_PATH
}

install_crosstool_clang()
{
	local URL='https://download.01.org/0day-ci/cross-package'
	local file='clang/clang.tar.xz'

	download_extract "$URL/$file" || {
		echo "Failed to download $URL/$file"
		return 1
	}
}

install_crosstool_gcc()
{
	[[ $URL ]] || local URL='https://download.01.org/0day-ci/cross-package'
	local list=/tmp/0day-ci-crosstool-files

	timeout 3m lftp -c "open $URL/ && find -d 3" | sort -V > $list || {
		echo "Cannot get list from $URL"
		echo "Please set new url, e.g. export URL=https://cdn.kernel.org/pub/tools/crosstool/files/bin/x86_64"
		return 1
	}

	local file
	local gcc_arch_pattern=$(echo "${gcc_arch}" | sed 's/*/.*/g')

	local gcc_version
	[[ $COMPILER =~ - ]] && gcc_version=${COMPILER##*-}
	if [[ $gcc_version ]]; then
		# for arch has more than 1 cross tool available, like x86_64-gcc-9.3.0-nolibc_arm-linux-gnueabi.tar.xz
		# and x86_64-gcc-9.3.0-nolibc_arm-linux-gnueabihf.tar.xz for arm, match "arm-linux-gnueabi." instead of
		# "arm-linux-gnueabi" to get single tool package which match exactly.
		file=$(grep "${gcc_arch_pattern}\..*tar\.xz$" $list | grep "${gcc_version}" | tail -1)
	else
		file=$(grep "${gcc_arch_pattern}\..*tar\.xz$" $list | tail -1)
	fi
	[[ $file ]] || {
		echo "Cannot find $gcc_arch_pattern under $URL check $list"
		echo "Please set new url, e.g. export URL=https://cdn.kernel.org/pub/tools/crosstool/files/bin/x86_64"
		return 1
	}

	rm $list

	download_extract "$URL/$file" || {
		echo "Failed to download $URL/$file"
		return 1
	}
}

install_crosstool()
{
	if is_clang_worker; then
		install_crosstool_clang || {
			echo "clang crosstool install failed"
			return 1
		}
	else
		install_crosstool_gcc || {
			echo "gcc crosstool install failed"
			return 1
		}
	fi
}

install_cross_compiler()
{
	install_packages && install_crosstool
}

setup_gcc_exec()
{
	gcc_exec=($COMPILER_INSTALL_PATH/${COMPILER}*/${gcc_arch}/bin/${gcc_arch}-gcc)
	[[ -x $gcc_exec ]] || install_cross_compiler || {
		echo "Install gcc cross compiler failed"
		return 1
	}

	gcc_exec=($COMPILER_INSTALL_PATH/${COMPILER}*/${gcc_arch}/bin/${gcc_arch}-gcc)
	[[ -x $gcc_exec ]] || {
		echo "No cross compiler for $ARCH"
		return 1
	}

	# use highest available version
	gcc_evec=$(tr ' ' '\n' <<< ${gcc_exec[@]} | sort -V | tail -n1)
}

update_path_env_for_parisc()
{
	local gcc_arch=$1
	local gcc_exec
	setup_gcc_exec || return
	gcc_path=$(dirname $gcc_exec)
	[[ $PATH =~ $gcc_path ]] || export PATH=$gcc_path:$PATH
}

setup_compiler_for_parisc()
{
	local gcc_arch=hppa-linux
	update_path_env_for_parisc $gcc_arch || return
	if grep -s -q 'CONFIG_64BIT=y' $BUILD_DIR/.config; then
		# 64bit build needs both hppa-linux and hppa64-linux
		# > Assembler messages:
		# > ../arch/parisc/kernel/vdso32/sigtramp.S:39: Error: unknown pseudo-op: `.proc'
		# > ../arch/parisc/kernel/vdso32/restart_syscall.S:16: Error: bad or irreducible absolute expression
		# > ../arch/parisc/kernel/vdso32/sigtramp.S:40: Error: unknown pseudo-op: `.callinfo'
		gcc_arch=hppa64-linux
		update_path_env_for_parisc $gcc_arch || return
	fi
	echo "PATH=$PATH"
}

setup_compiler_for_xtensa()
{
	local variant

	variant=$(grep -s -h '^CONFIG_XTENSA_VARIANT_CUSTOM_NAME=' $BUILD_DIR/.config |
		  head -n1 |
		  cut -f2 -d'"')

	if [[ "$variant" = 'fsf' ]]; then
		gcc_arch=$ARCH-linux
	elif [[ $variant ]]; then
		gcc_arch=xtensa-${variant}-linux
	else
		gcc_arch=$ARCH-linux
	fi
}

setup_crosstool_gcc()
{
	local gcc_arch
	local gcc_exec

	case $ARCH in
		i386|x86_64)
			gcc_arch=
			;;
		arc)
			# start to support big endian arc toolchain form gcc-9.3.0
			# for earlier gcc version, will failed to find arceb-elf for
			# big endian arceb-elf tool chain
			if grep -q 'CONFIG_CPU_BIG_ENDIAN=y' $BUILD_DIR/.config; then
				gcc_arch=arceb-elf
			else
				gcc_arch=arc-elf
			fi
			;;
		c6x)
			gcc_arch=$ARCH-elf
			;;
		um)
			gcc_arch=
			;;
		arm)
			gcc_arch=arm-linux-gnueabi
			;;
		arm64)
			gcc_arch=aarch64-linux*
			;;
		powerpc)
			gcc_arch=powerpc-linux
			grep -q 'CONFIG_PPC64=y' $BUILD_DIR/.config && {
				if grep -q 'CONFIG_CPU_LITTLE_ENDIAN=y' $BUILD_DIR/.config; then
					gcc_arch=powerpc64le-linux
				else
					gcc_arch=powerpc64-linux
				fi
			}
			;;
		blackfin)
			gcc_arch=bfin-uclinux
			;;
		sh)
			gcc_arch=sh4-linux
			;;
		parisc|parisc64)
			setup_compiler_for_parisc || return
			;;
		openrisc)
			gcc_arch=or1k-linux
			;;
		riscv)
			if grep -q 'CONFIG_32BIT=y' $BUILD_DIR/.config; then
				gcc_arch=riscv32-linux
			else
				gcc_arch=riscv64-linux
			fi
			;;
		s390)
			gcc_arch=s390-linux
			;;
		tile|tilegx)
			gcc_arch=tilegx-linux
			;;
		mn10300)
			gcc_arch=am33_2.0-linux
			;;
		nds32)
			gcc_arch=nds32le-linux
			;;
		xtensa)
			setup_compiler_for_xtensa
			;;
		loongarch)
			gcc_arch=loongarch64-linux
			;;
		*)
			gcc_arch=$ARCH-linux
			;;
	esac

	if [[ $gcc_arch ]]; then
		setup_gcc_exec || return
		opt_cross="CROSS_COMPILE=${gcc_exec%gcc}"

		# load build-in depends libs
		local deplibs_path=($COMPILER_INSTALL_PATH/${COMPILER}*/${gcc_arch}/libexec/gcc/${gcc_arch}/*)
		deplibs_path=$(tr ' ' '\n' <<< ${deplibs_path[@]} | sort -V | tail -n1)
		[[ -d $deplibs_path ]] && export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$deplibs_path

		install_dependence "$gcc_exec" || return
	else
		opt_cross=
	fi

	return 0
}

is_llvm_equal_one_supported()
{
	[[ $kernel_version_major ]] || return

	[[ $kernel_version_major -lt 5 ]] && return 1
	[[ $kernel_version_major -eq 5 && $kernel_version_minor -lt 7 ]] && return 1

	grep -q -F "ifneq (\$(LLVM),)" Makefile || return

	[[ $ARCH = "s390" ]] && return 1
	[[ $ARCH =~ "powerpc" || $ARCH =~ "mips" || $ARCH =~ "riscv" ]] &&
	[[ $kernel_version_major -eq 5 && $kernel_version_minor -lt 18 ]] && return 1

	return 0
}

setup_crosstool_clang()
{
	local cross_clang=("$COMPILER_INSTALL_PATH"/clang/bin/clang)
	[[ -x $cross_clang ]] || install_cross_compiler || {
		echo "Install clang compiler failed"
		return 1
	}

	install_dependence "$cross_clang" || return

	local cross_clang_path=$(dirname $cross_clang)
	local opt_ldd="LD=${cross_clang_path}/ld.lld HOSTLD=${cross_clang_path}/ld.lld"
	local opt_objcopy="OBJCOPY=llvm-objcopy"
	[[ $ARCH = s390 ]] && {
		opt_ldd=
		# from binutils-s390x-linux-gnu
		opt_objcopy="OBJCOPY=/usr/s390x-linux-gnu/bin/objcopy"
	}

	export PATH="$cross_clang_path:$PATH"
	# https://www.kernel.org/doc/html/latest/kbuild/llvm.html
	local opt_default_cross="HOSTCC=$cross_clang CC=$cross_clang $opt_ldd $opt_objcopy \
		AR=llvm-ar NM=llvm-nm STRIP=llvm-strip OBJDUMP=llvm-objdump OBJSIZE=llvm-size READELF=llvm-readelf HOSTCXX=clang++ HOSTAR=llvm-ar"

	local opt_llvm_ias=
	if is_llvm_equal_one_supported; then
		opt_cross="LLVM=1"
		[[ $kernel_version_major -lt 5 || ($kernel_version_major -eq 5 && $kernel_version_minor -lt 15) ]] && opt_llvm_ias="LLVM_IAS=1"
	else
		opt_cross=$opt_default_cross
	fi

	# TODO: CROSS_COMPILE is not necessary for new kernel
	if [[ $ARCH = "arm64" ]]; then
		opt_cross="$opt_cross CROSS_COMPILE=aarch64-linux-gnu-"
	elif [[ $ARCH = "arm" ]]; then
		opt_cross="$opt_cross CROSS_COMPILE=arm-linux-gnueabi-"
	elif [[ $ARCH = "s390" ]]; then
		opt_cross="$opt_default_cross CROSS_COMPILE=s390x-linux-gnu-"
	elif [[ $ARCH = "hexagon" ]]; then
		opt_cross="$opt_cross CROSS_COMPILE=hexagon-linux-"
		opt_llvm_ias="LLVM_IAS=1"
	elif [[ $ARCH = "powerpc" ]]; then
		local cross_compile='powerpc-linux-gnu-'
		grep -q 'CONFIG_PPC64=y' $BUILD_DIR/.config && {
			if grep -q 'CONFIG_CPU_LITTLE_ENDIAN=y' $BUILD_DIR/.config; then
				cross_compile='powerpc64le-linux-gnu-'
			else
				cross_compile='powerpc64-linux-gnu-'
			fi
		}
		opt_cross="$opt_cross CROSS_COMPILE=$cross_compile"
		[[ $kernel_version_major -eq 5 && $kernel_version_minor -gt 14 && $kernel_version_minor -lt 18 ]] && opt_llvm_ias="LLVM_IAS=0"
	elif [[ $ARCH = "riscv" ]]; then
		if grep -q 'CONFIG_32BIT=y' $BUILD_DIR/.config; then
			opt_cross="$opt_cross $(COMPILER=gcc && setup_crosstool_gcc && echo $opt_cross)"
		else
			opt_cross="$opt_cross CROSS_COMPILE=riscv64-linux-gnu-"
		fi
	else
		opt_cross="$opt_cross CROSS_COMPILE=$ARCH-linux-gnu-"
	fi
	[[ $opt_llvm_ias ]] && opt_cross="$opt_cross $opt_llvm_ias"
	:
}

setup_crosstool()
{
	local kernel_version=$(make kernelversion)
	local kernel_version_major=$(echo "$kernel_version" | cut -d. -f1)
	local kernel_version_minor=$(echo "$kernel_version" | cut -d. -f2)

	if is_clang_worker; then
		setup_crosstool_clang
	else
		setup_crosstool_gcc
	fi
}

check_install_path || {
	echo "Please set COMPILER_INSTALL_PATH to specify compiler install path"
	echo "E.g. COMPILER_INSTALL_PATH=\$HOME/0day COMPILER=clang make.cross ARCH=x86_64"
	echo
	exit 1
}

setup_crosstool || {
	echo "setup_crosstool failed"
	exit 1
}

[[ "$*" =~ (-j|--jobs) ]] || {
	nr_cpu=$(getconf _NPROCESSORS_CONF)
	opt_jobs="--jobs=$((nr_cpu * 2))"
}

[[ "$*" =~ "ARCH=$ARCH" ]] || {
	opt_arch="ARCH=$ARCH"
}

[[ -f arch/$ARCH/boot/dts/Makefile ]] && make_dts="CONFIG_OF_ALL_DTBS=y CONFIG_DTC=y"

[[ -f .make-env ]] && source ./.make-env

if [[ -d source && -L source ]]; then
	echo make --keep-going -C source O=$PWD $make_dts $opt_arch $opt_cross $subarch $opt_jobs "$@"
	exec make --keep-going -C source O=$PWD $make_dts $opt_arch $opt_cross $subarch $opt_jobs "$@"
else
	echo make --keep-going $O $make_dts $opt_arch $opt_cross $subarch $opt_jobs "$@"
	exec make --keep-going $O $make_dts $opt_arch $opt_cross $subarch $opt_jobs "$@"
fi