configure

#!/usr/bin/env sh

set -e

usage() {
    {
        echo "[ENV]=[VAL] $0 [FLAGS...]"
        echo '    --help                Print help/usage'
        echo '    --use-clang           Use clang instead of default ($CC or cc) compiler'
        echo '    --use-gcc             Use gcc instead of default ($CC or cc) compiler'
        echo '    --use-harden          Harden the binary'
        echo '    --use-strip           Strip the generated binary'
        echo '    --use-pedantic        Enable -Wpedantic -pedantic flags'
        echo '    --use-warnings        Enable -Wall and -Wextra'
        echo '    --use-werror          Enable -Werror'
        echo '    --use-lto             Enable LTO'
        echo '    --use-config          Install configuration to /usr/share/yafetch/init.lua or $CONF'
        echo '    --use-extreme-strip   Configure strip flags to be extreme'
        echo '    --use-install         Enable the `install` and `uninstall` makefile entries'
        echo '    --use-optimise        Add optimisation flags'
        echo '    --use-debug           Add debug symbols and generally optimise for debugging'
        echo '    --use-prog-debug      Enable binary-level debug logging'
        echo '    --use-march           Enable -march=native'
        echo ''
        echo '    $LUAPC                Lualib pkg-config name'
    } >&2
}

die() {
    echo "$@" 1>&2
    exit 1
}

check_cmd() {
    echo "Checking for $1..."
    command -v "$1" >/dev/null || die "$1 was not found"
}

check_pkg() {
    echo "Checking for $1.pc..."
    pkg-config --cflags "$1" >/dev/null || die "$1.pc was not found"
}

main() {
    if [ ! "$1" ]; then
        usage
        exit 1
    fi

    LUAPC="${LUAPC:-lua5.4}"

    check_cmd 'make'
    check_cmd 'pkg-config'
    check_pkg "$LUAPC"

    project='yafetch'

    compiler='$(CC)'
    cflags='-std=c99 -D_POSIX_C_SOURCE=200112L -D_ISOC99_SOURCE'
    ldflags=''
    stripflags=''
    strip_enable=0
    config_enable=0
    install_enable=0

    for arg in "$@"; do
        case "$arg" in
        --help)
            usage
            exit
            ;;
        --use-clang)
            check_cmd 'clang'
            compiler='clang'
            ;;
        --use-gcc)
            check_cmd 'gcc'
            compiler='gcc'
            ;;
        --use-harden)
            cflags="$cflags -g -fstack-protector-strong -fstack-protector -fPIE -pie -D_FORTIFY_SOURCE=2 -O2 -Wno-unused-result -Wno-unused-command-line-argument"
            ldflags="$ldflags -Wl,-z,relro,-z,now"
            ;;
        --use-strip)
            strip_enable=1
            ;;
        --use-pedantic)
            cflags="$cflags -Wpedantic -pedantic"
            ;;
        --use-warnings)
            cflags="$cflags -Wall -Wextra -Wformat -Wformat-security"
            ;;
        --use-werror)
            cflags="$cflags -Werror"
            ;;
        --use-lto)
            cflags="$cflags -flto"
            ldflags="$ldflags -flto"
            ;;
        --use-config)
            config_enable=1
            ;;
        --use-extreme-strip)
            stripflags='--strip-all -N __gentoo_check_ldflags__ -R .comment -R .GCC.command.line --remove-section=.eh_frame --remove-section=.eh_frame_hdr --remove-section=.gnu.hash --remove-section=.eh_frame_hdr --remove-section=.eh_frame_ptr --remove-section=.note.gnu.gold-version --remove-section=.note.gnu.build-id --remove-section=.note.ABI-tag --remove-section=.note --remove-section=.gnu.version --remove-section=.comment --strip-debug --strip-unneeded'
            ;;
        --use-install)
            install_enable=1
            ;;
        --use-optimise)
            cflags="$cflags -O2 -ffast-math"
            ldflags="$ldflags -O2"
            ;;
        --use-debug)
            cflags="$cflags -g -g3 -O0 -fno-eliminate-unused-debug-types"
            ;;
        --use-prog-debug)
            cflags="$cflags -DDEBUG"
            ;;
        --use-march)
            cflags="$cflags -march=native"
            ;;
        *)
            die "Flag $arg not found"
            ;;
        esac
    done

    echo 'Configuring lua...'
    cflags="$cflags $(pkg-config --cflags "${LUAPC}" || die 'pkg-config cflags failed for lua5.4')"
    ldflags="$ldflags $(pkg-config --libs "${LUAPC}" || die 'pkg-config ldflags failed for lua5.4')"

    after=''
    all='all after clean'

    {
        echo 'OBJECTS := src/script.o src/func.o src/main.o'
        echo "CFLAGS := \$(CFLAGS) $cflags"
        echo "LDFLAGS := \$(LDFLAGS) $ldflags"
        echo "CC := $compiler"

        echo 'all: $(OBJECTS)'
        printf "\t%s\n" "\$(CC) \$(CFLAGS) \$^ \$(LDFLAGS) -o $project"
        printf "\t%s\n" "make after"

        echo 'clean:'
        printf "\t%s\n" "rm -f $project \$(OBJECTS)"

        if [ "$config_enable" = 1 ]; then
            echo 'CONF ?= /usr/share/yafetch'
            echo 'y_config:'
            printf "\t%s\n" 'rm -rf $(DESTDIR)$(CONF)/init.lua'
            printf "\t%s\n" 'mkdir -p $(DESTDIR)$(CONF)'
            printf "\t%s\n" 'install -Dm644 init.lua $(DESTDIR)$(CONF)'

            all="$all y_config"
        fi

        if [ "$strip_enable" = 1 ]; then
            echo "STRIPFLAGS := \$(STRIPFLAGS) $stripflags"
            echo 'y_strip:'
            printf "\t%s\n" "strip $project \$(STRIPFLAGS) -o $project"

            after="$after y_strip"
        fi

        if [ "$install_enable" = 1 ]; then
            echo 'PREFIX ?= /usr/local'
            echo 'BINDIR ?= $(PREFIX)/bin'

            echo "install: $project"
            printf "\t%s\n" 'mkdir -p $(DESTDIR)$(BINDIR)'
            printf "\t%s\n" 'install -Dm755 yafetch $(DESTDIR)$(BINDIR)'

            echo 'uninstall:'
            printf "\t%s\n" 'rm -i $(DESTDIR)$(BINDIR)/yafetch'

            all="$all install uninstall"
        fi

        echo 'after:'
        if [ "$after" ]; then
            printf "\t%s\n" "make $after -j$(nproc --all)"
        else
            printf "\t%s\n" "-@echo 'No after-compile phase'"
        fi

        echo ".PHONY: $all $after"
    } >Makefile
}

main "$@"