#!/bin/bash

export LINUX_VERSION="6.12.1"

# Function to handle errors
error_handler() {
    local exit_code=$?
    local line_number=$1
    local file_name=$2
    echo "Error in file: $file_name, line: $line_number, reason: Command exited with status $exit_code"
}

# Set the trap to catch errors
trap 'error_handler $LINENO $0' ERR

set -eo pipefail

if [ ! -d "./sources" ]; then
    echo "Run this script from the right directory"
    exit 1
fi

export BASE_DIR=$(pwd)

if [ -z "$ARCH" ]; then
    echo "You must set a target architecture among supported ones:"
    echo "i386"
    echo "x86_64"
    echo "armv5"

    exit 1
fi

if [ -z "$LFS_TGT" ]; then
    export LFS_TGT="$ARCH-lfs-linux-gnu"
    echo "Target triplet set to '$LFS_TGT'. You can specify another one with the LFS_TGT env var."
fi

if [ ! -d "$LFS_TGT" ]; then
    export LFS="$(pwd)/out/$LFS_TGT/rootfs"

    echo "Target rootfs set to '$LFS_TGT'. You can override this by setting the LFS_TGT env var."
fi

# test bash
bash --version
echo ""

# test rsync
rsync --version
echo ""

# test clang
clang --version
echo ""

# test lld
ld --version
echo ""

make --version
echo ""

# Create the target directory
mkdir -p "$LFS"
export STEPS_DIR="$LFS/../steps/"
mkdir -vp "$STEPS_DIR"

export LFS_TOOLS="$LFS/tools"
mkdir -vp "$LFS_TOOLS"

export PATH="$LFS_TOOLS/bin/:$PATH"

export LFS_BUILD="$LFS/../"

unset CFLAGS

# Create a directory layout
if [ ! -d "$LFS/etc" ]; then
    mkdir -pv $LFS/{etc,var} $LFS/usr/{bin,lib,sbin}

    for i in bin lib sbin; do
        ln -sv usr/$i $LFS/$i
    done

    case $ARCH in
        x86_64) mkdir -pv $LFS/lib64 ;;
    esac
fi

# Build binutils
if [ ! -f "$STEPS_DIR/binutils" ]; then
    if [ ! -d "$LFS_BUILD/binutils" ]; then
        tar -xf "$BASE_DIR/sources/binutils-2.43.tar.zst"
        mv "binutils-2.43" "$LFS_BUILD/binutils"
    fi
    cd "$LFS_BUILD/binutils"

    mkdir -vp build
    cd        build
    "../configure"                      \
        --prefix=$LFS_TOOLS             \
        --with-sysroot=$LFS             \
        --target=$LFS_TGT               \
        --disable-nls                   \
        --enable-gprofng=no             \
        --disable-werror                \
        --enable-new-dtags              \
        --disable-multilib              \
        --enable-default-hash-style=gnu
    make configure-host
    make -j 32
    make install

    cd "$BASE_DIR"
    rm -rf binutils-2.43
    touch "$STEPS_DIR/binutils"
fi

# Build gcc
if [ ! -f "$STEPS_DIR/gcc" ]; then
    if [ ! -d "$LFS_BUILD/gcc" ]; then
        tar -xzf "$BASE_DIR/sources/gcc-14.2.0.tar.gz"
        mv "gcc-14.2.0" "$LFS_BUILD/gcc"
    fi
    cd "$LFS_BUILD/gcc/"
    tar -xf "$BASE_DIR/sources/mpfr-4.2.1.tar.xz"
    mv -v mpfr-4.2.1 mpfr
    tar -xf "$BASE_DIR/sources/gmp-6.3.0.tar.xz"
    mv -v gmp-6.3.0 gmp
    tar -xf "$BASE_DIR/sources/mpc-1.3.1.tar.gz"
    mv -v mpc-1.3.1 mpc

    # On x86_64 hosts, set the default directory name for 64-bit libraries to “lib”
    case $(uname -m) in
    x86_64)
        sed -e '/m64=/s/lib64/lib/' \
            -i.orig gcc/config/i386/t-linux64
    ;;
    esac

    mkdir -vp build
    cd        build

    "../configure"                \
        --target=$LFS_TGT         \
        --prefix=$LFS_TOOLS       \
        --with-glibc-version=2.40 \
        --with-sysroot=$LFS       \
        --with-newlib             \
        --without-headers         \
        --enable-default-pie      \
        --enable-default-ssp      \
        --disable-nls             \
        --disable-shared          \
        --disable-multilib        \
        --disable-threads         \
        --disable-libatomic       \
        --disable-libgomp         \
        --disable-libquadmath     \
        --disable-libssp          \
        --disable-libvtv          \
        --disable-libstdcxx       \
        --disable-decimal-float   \
        --disable-multilib        \
        --enable-languages=c,c++
    make -j 32 # if build fails add --disable-libsanitizer
    make install
    cd "$BASE_DIR"
    rm -rf "$LFS_BUILD/gcc/build" # Do not remove the whole gcc directory: we need it for libstdc++
    touch "$STEPS_DIR/gcc"
fi

# Install kernel headers
if [ ! -f "$STEPS_DIR/linux-headers" ]; then
    if [ ! -d "$LFS_BUILD/linux" ]; then
        tar -xzf "$BASE_DIR/sources/linux-$LINUX_VERSION.tar.gz"
        mv "linux-$LINUX_VERSION" "$LFS_BUILD/linux"
    fi
    cd "$LFS_BUILD/linux"
    make mrproper
    LD="$LFS_TGT-ld" CC="$LFS_TGT-gcc" CXX="$LFS_TGT-g++" AR="$LFS_TGT-ar" RANLIB="$LFS_TGT-ranlib" make headers_install ARCH="$ARCH" INSTALL_HDR_PATH="$LFS/usr"
    cd "$BASE_DIR"
    rm -rf "$LFS_BUILD/linux"
    touch "$STEPS_DIR/linux-headers"
fi

# build glibc
if [ ! -f "$STEPS_DIR/glibc" ]; then
    if [ ! -d "$LFS_BUILD/glibc" ]; then
        tar -xzf "$BASE_DIR/sources/glibc-2.40.tar.gz"
        mv "glibc-2.40" "$LFS_BUILD/glibc"
    fi
    cd "$LFS_BUILD/glibc"

    mkdir -vp build
    cd        build

    echo "rootsbindir=/usr/sbin" > configparms

    "../configure"                       \
      --prefix=/usr                      \
      --host=$LFS_TGT                    \
      --build=$(../scripts/config.guess) \
      --enable-kernel=4.19               \
      --with-headers=$LFS/usr/include    \
      --disable-debug                    \
      --without-selinux                  \
      --disable-nscd                     \
      libc_cv_slibdir=/usr/lib
    make -j 32
    make DESTDIR=$LFS install
    sed '/RTLDLIST=/s@/usr@@g' -i $LFS/usr/bin/ldd

    cd "$BASE_DIR"
    rm -rf "$LFS_BUILD/glibc"
    touch "$STEPS_DIR/glibc"
fi

# test the cross toolchain
which -- $LFS_TGT-as || echo $LFS_TGT-as is not in the PATH
echo 'int main(){}' | "$LFS_TGT-gcc" -xc -
"$LFS_TGT-readelf" -l a.out > test_compiler
cat test_compiler | grep ld-linux
rm -v a.out test_compiler

# build libstdc++
if [ ! -f "$STEPS_DIR/libstdcxx" ]; then
    bash unpack-gcc.sh
    cd "$LFS_BUILD/gcc"
    
    mkdir -vp build_libstdcxx
    cd        build_libstdcxx

    #PATH="$PATH:$LFS_TOOLS/bin" RANLIB="$LFS_TOOLS/bin/$LFS_TGT-ranlib" AR="$LFS_TOOLS/bin/$LFS_TGT-ar" LD="$LFS_TOOLS/bin/$LFS_TGT-ld"  CC="$LFS_TOOLS/bin/$LFS_TGT-gcc" CXX="$LFS_TOOLS/bin/$LFS_TGT-g++"
    bash \
        ../libstdc++-v3/configure         \
        --host=$LFS_TGT                   \
        --build=$(../config.guess)        \
        --prefix=/usr                     \
        --disable-multilib                \
        --disable-nls                     \
        --disable-libstdcxx-pch           \
        --with-gxx-include-dir=/tools/$LFS_TGT/include/c++/14.2.0
    make -j 32
    make DESTDIR=$LFS install
    # Remove the libtool archive files because they are harmful for cross-compilation
    rm -v $LFS/usr/lib/lib{stdc++{,exp,fs},supc++}.la

    cd "$BASE_DIR"
    rm -rf "$LFS_BUILD/gcc"
    touch "$STEPS_DIR/libstdcxx"
fi

# build m4
if [ ! -f "$STEPS_DIR/m4" ]; then
    if [ ! -d "$LFS_BUILD/m4" ]; then
        tar -xzf "$BASE_DIR/sources/m4-1.4.19.tar.gz"
        mv "m4-1.4.19" "$LFS_BUILD/m4"
    fi
    cd "$LFS_BUILD/m4"

    #mkdir -vp build
    #cd        build

    echo "rootsbindir=/usr/sbin" > configparms

    "./configure"                      \
    --prefix=/usr                      \
    --host=$LFS_TGT                    \
    --build=$(build-aux/config.guess)  \
    
    make -j 32
    make DESTDIR=$LFS install

    cd "$BASE_DIR"
    rm -rf "$LFS_BUILD/m4"
    touch "$STEPS_DIR/m4"
fi