kmesh_compile_env_pre.sh

# libboundscheck is not available in some environments, install by source
function install_libboundscheck() {
    if [ ! -f /usr/local/lib/libboundscheck.so ]; then
	    git clone https://github.com/openeuler-mirror/libboundscheck.git
	    cd libboundscheck
	    make CC=gcc
	    cp lib/libboundscheck.so /usr/local/lib
	    cp include/* /usr/include
	    cd ../
	    rm -rf libboundscheck
    fi
}

function dependency_pkg_install() {
    
    if command -v apt > /dev/null; then
        echo "Checking for required packages on a Debian-based system..."

      
        packages=(git make clang libbpf-dev llvm linux-tools-generic protobuf-compiler libprotobuf-dev libprotobuf-c-dev protobuf-c-compiler cmake pkg-config)

       
        update_needed=false
        for pkg in "${packages[@]}"; do
            if ! dpkg -s "$pkg" >/dev/null 2>&1; then
                update_needed=true
                break
            fi
        done

       
        if [ "$update_needed" = true ]; then
            apt-get update
        fi

        # Install each missing package
        for pkg in "${packages[@]}"; do
            if ! dpkg -s "$pkg" >/dev/null 2>&1; then
                echo "Installing $pkg..."
                apt-get install -y "$pkg"
            else
                echo "$pkg is already installed."
            fi
        done

        # Install libboundscheck if it’s not already present
        install_libboundscheck

    # Check if running on a Red Hat-based system (yum)
    elif command -v yum > /dev/null; then
        echo "Checking for required packages on a Red Hat-based system..."

        # List of required packages
        packages=(git make clang llvm libboundscheck protobuf protobuf-c protobuf-c-devel bpftool libbpf libbpf-devel cmake pkg-config)

        # Install each missing package
        for pkg in "${packages[@]}"; do
            if ! rpm -q "$pkg" >/dev/null 2>&1; then
                echo "Installing $pkg..."
                yum install -y "$pkg"
            else
                echo "$pkg is already installed."
            fi
        done
    fi
}


# fix bug in libbpf
function fix_libbpf_bug() {
    if ! grep -iq "#define SEC(name) __attribute__((section(name), used))" /usr/include/bpf/bpf_helpers.h; then
	    LINENUMBER=$(grep -n '#define SEC(name)' /usr/include/bpf/bpf_helpers.h | cut -f1 -d:)
	    if [[ ! -z "$LINENUMBER" ]]; then
		    sed -i "${LINENUMBER} i #if __GNUC__ && !__clang__\n#define SEC(name) __attribute__((section(name), used))\n#else" /usr/include/bpf/bpf_helpers.h
		    LINENUMBER=$((LINENUMBER+8))
		    sed -i "${LINENUMBER} a \\#endif" /usr/include/bpf/bpf_helpers.h
	    fi
    fi
}

function adapt_low_version_kernel() {
    # adapt less insn in kernel 4.19, only 4096, so modify KMESH_PER_ENDPOINT_NUM into 15
    if [ "$(uname -r | cut -d '.' -f 1)" -le 4 ]; then
            sed -i 's/\(KMESH_PER_ENDPOINT_NUM\).*/\1 15/g' bpf/kmesh/ads/include/config.h
    fi
}

# Special case: 
# There is a structure that is only defined in certain environments and is 
# only used during the compilation stage. Therefore, the definition of this 
# structure in the include directory is dynamically adjusted according to 
# the current compilation environment during compilation.
function adapt_include_env {
    if grep -q "struct bpf_mem_ptr {" /usr/include/linux/bpf.h; then
        sed -i '/bpf_mem_ptr/{N;N;N;N;d;}' bpf/kmesh/ads/include/kmesh_common.h
    fi
}

function kmesh_set_env(){
    if [ "$(arch)" == "x86_64" ]; then
            export EXTRA_CDEFINE="-D__x86_64__"
            export C_INCLUDE_PATH=/usr/include/x86_64-linux-gnu:$C_INCLUDE_PATH
    fi

    if [ "$(arch)" == "aarch64" ]; then
            export C_INCLUDE_PATH=/usr/include/aarch64-linux-gnu:$C_INCLUDE_PATH
    fi
    export EXTRA_GOFLAGS="-gcflags=\"-N -l\" -buildmode=pie"
    export EXTRA_CFLAGS="-O0 -g"
}

# adjust the range of BPF code compilation based on the kernel is enhanced
function bpf_compile_range_adjust() {
    if [ "$ENHANCED_KERNEL" == "enhanced" ]; then
            sed -i '/ads\/tracepoint\.c/s/\(.*\)generate/\/\/go:generate/' bpf/kmesh/bpf2go/bpf2go.go
            sed -i '/ads\/sockops\.c/s/\(.*\)generate/\/\/go:generate/' bpf/kmesh/bpf2go/bpf2go.go
    else
            sed -i '/ads\/tracepoint\.c/s/\(.*\)generate/\/\/not go:generate/' bpf/kmesh/bpf2go/bpf2go.go
            sed -i '/ads\/sockops\.c/s/\(.*\)generate/\/\/not go:generate/' bpf/kmesh/bpf2go/bpf2go.go
    fi
}

function set_enhanced_kernel_env() {
    # we use /usr/include/linux/bpf.h to determine the runtime environment’s
    # support for kmesh. Considering the case of online image compilation, a
    # variable KERNEL_HEADER_LINUX_BPF is used here to specify the path of the
    # source of macro definition.
    # When using an online compiled image, /usr/include/linux/bpf.h in host
    # machine  will be mounted to config/linux-bpf.h.
    # Otherwise, /usr/include/linux/bpf.h from the current compilation
    # environment will be obtained
    export KERNEL_HEADER_LINUX_BPF=$ROOT_DIR/config/linux-bpf.h
    if [ ! -f "$KERNEL_HEADER_LINUX_BPF" ]; then
            export KERNEL_HEADER_LINUX_BPF=/usr/include/linux/bpf.h
    fi

    if grep -q "FN(parse_header_msg)" $KERNEL_HEADER_LINUX_BPF; then
            export ENHANCED_KERNEL="enhanced"
    else
            export ENHANCED_KERNEL="unenhanced"
    fi
}

function prepare() {
    if [ "${SKIP_DEPENDENCY_INSTALL}" != "true" ]; then
        dependency_pkg_install
    fi
    fix_libbpf_bug
    adapt_low_version_kernel
    adapt_include_env
    kmesh_set_env
    bash kmesh_macros_env.sh
    bash kmesh_bpf_env.sh
    bpf_compile_range_adjust
}