#!/usr/bin/env bash
# SPDX-License-Identifier: MIT
#
# Copyright (C) 2021 Nathan Chancellor
#
# The shebang is just for shellcheck auditing; this script needs to be sourced and
# called by the function name otherwise it literally does nothing. It works in
# bash and zsh.
#
# Builds GCC and binutils for exclusively building kernels
#
# This can be downloaded and sourced without any of the other scripts in this repo.
#
# $ curl -LSsO https://github.com/nathanchance/android-tools/raw/main/scripts/bldgcc
#
# Open the bldgcc file to make sure it matches this one.
#
# $ source bldgcc
#
# Usage:
# $ bldgcc arm arm64
#
# By default, the script will contain everything to a 'gcc' folder in ${PWD}.
# To change where that gcc folder is, either 'export GCC_TC_FOLDER=<value>' or
# 'GCC_TC_FOLDER=<value> bldgcc'.
#
# By default, the GCC and binutils versions will be the latest available.
# To change the versions, either 'export GCC_VERSION=<value> BINUTILS_VERSION=<value>'
# or 'GCC_VERSION=<value> BINUTILS_VERSION=<value> bldgcc'.
#
# The possible versions can be found here:
# https://mirrors.kernel.org/gnu/gcc/
# https://mirrors.kernel.org/gnu/binutils/
#
# This script is designed to build release versions of this software, not development
# versions. If you want to do that, it's not hard to modify this script to do that or
# use https://github.com/USBhost/build-tools-gcc
function bldgcc() { (
    BLD_OPTS=(--toolchain)
    TARGETS=()

    # Get parameters
    [[ ${#} -eq 0 ]] && {
        echo "ERROR: This function needs targets!" >&2
        echo "Some of the possible options (can provide more than one):" >&2
        echo "      arm, arm64, m68k, mips, mipsel, powerpc, powerpc64, powerpc64le, riscv64, s390x, x86_64" >&2
        exit 1
    }
    while ((${#})); do
        case ${1} in
            --binutils | --gcc | --toolchain) BLD_OPTS=("${1}") ;;
            all) TARGETS=(arm arm64 m68k mips mipsel powerpc powerpc64 powerpc64le riscv64 s390x x86_64) ;;
            *) TARGETS+=("${1}") ;;
        esac
        shift
    done

    # Create folders
    GCC_BLD=${GCC_TC_FOLDER:=${PWD}/gcc}/build
    mkdir -p "${GCC_TC_FOLDER}"
    [[ ! -d ${GCC_BLD} ]] && git -C "${GCC_TC_FOLDER}" clone https://github.com/nathanchance/buildall build
    cd "${GCC_BLD}" || {
        echo "buildall clone failed!" >&2
        exit 1
    }

    # Download GCC
    [[ -z ${GCC_VERSION} ]] && GCC_VERSION=11.2.0
    GCC_SOURCE=gcc-${GCC_VERSION}
    [[ ! -d ${GCC_SOURCE} ]] && curl -LSs https://mirrors.kernel.org/gnu/gcc/${GCC_SOURCE}/${GCC_SOURCE}.tar.xz | tar -xJf -

    # Download binutils
    [[ -z ${BINUTILS_VERSION} ]] && BINUTILS_VERSION=2.37
    BINUTILS_SOURCE=binutils-${BINUTILS_VERSION}
    [[ ! -d ${BINUTILS_SOURCE} ]] && curl -LSs https://mirrors.kernel.org/gnu/binutils/${BINUTILS_SOURCE}.tar.xz | tar -xJf -

    # Create timert
    [[ ! -f timert ]] && make -j"$(nproc)"

    # Create config
    cat <<EOF >config
BINUTILS_SRC=${PWD}/${BINUTILS_SOURCE}
CHECKING=release
ECHO=/bin/echo
GCC_SRC=${PWD}/${GCC_SOURCE}
MAKEOPTS=-j$(nproc)
PREFIX=${PREFIX:-${GCC_TC_FOLDER}/${GCC_VERSION}}
EOF

    # Build the toolchains
    for TARGET in "${TARGETS[@]}"; do
        # Clean up previous artifacts, can cause a false failure
        rm -rf "${TARGET}"
        PATH=${PATH%%:\/mnt\/c\/*} ./build "${BLD_OPTS[@]}" "${TARGET}"
    done
); }