configure

#!/bin/sh

cd "$(dirname "$0")"

cc=""
ld=""

opt_cc_flag='--cc=CC'
opt_cc_help='Specifies a C compiler to override the default.'
opt_cc_do='cc="${arg#--cc=}"'

opt_ld_flag='--ld=LD'
opt_ld_help='Specifies a linker to override the default.'
opt_ld_do='ld="${arg#--ld=}"'

file_ext=""
opt_file_ext_flag='--file-ext={so,dylib}'
opt_file_ext_help='Specifies the filename extension for DLL files.'
opt_file_ext_do='file_ext="${arg#--file-ext=}"'

dllflags=""
dllflags_xpg8="-G"
dllflags_apple="-dylib"
dllflags_binutils="-shared"

opt_dllflags_flag='--dllflags=DLLFLAGS'
opt_dllflags_help='Specify flags for creating a DLL.'
opt_dllflags_do='dllflags="${arg#--dllflags=}"'

with=""

opt_with_flag='--with={x86,arm,ppc}'
opt_with_help='Specify architecture-specific additions.'
opt_with_do='with="$(echo "${arg#--with=}" | tr [a-z] [A-Z])"'

install_prefix=""
install_exec_prefix=""
install_libdir=""
install_includedir=""

opt_prefix_flag='--prefix=path'
opt_prefix_help='Specify the installation directory prefix.'
opt_prefix_do='install_prefix="${arg#--prefix=}"'

opt_exec_prefix_flag='--exec-prefix=path'
opt_exec_prefix_help='Specify the install prefix for machine-dependent files.'
opt_exec_prefix_do='install_exec_prefix="${arg#--exec-prefix=}"'

opt_libdir_flag='--libdir=path'
opt_libdir_help='Specify installation directory for library files.'
opt_libdir_do='install_libdir="${arg#--libdir=}"'

opt_includedir_flag='--includedir=path'
opt_includedir_help='Specify install directory for include header files.'
opt_includedir_do='install_includedir="${arg#--includedir=}"'

opts="\
cc ld file_ext dllflags with
prefix exec_prefix libdir includedir
"

case "$1" in
    -h|--help)
        echo Available Options:
        for opt in $opts ; do
            eval 'printf "  %-26s%-46s\n"' \
                 '"$opt_'$opt'_flag" "$opt_'$opt'_help"'
        done
        ;;

    *)
        for arg ; do
            for opt in $opts ; do
                eval 'flag="${opt_'$opt'_flag}"'
                eval 'do="${opt_'$opt'_do}"'
                if [ X"${arg%%=*}=" = X"${flag%=*}=" ] ; then
                    eval "$do"
                fi
            done
        done
        ;;
esac

if ! [ "$cc" ] ; then cc='${CC}' ; fi
if ! [ "$ld" ] ; then ld='${CC}' ; fi

if ! [ "$file_ext" ] ; then
    if [ "$(uname -s)" = Darwin ]
    then file_ext=dylib
    else file_ext=so
    fi
fi

if ! [ "$dllflags" ] ; then
    printf '%s\n' ".PHONY: getcc getld" > auto/configure-getcc.mk \
           "getcc:; echo ${cc}" "getld:; echo ${ld}"

    mkcc="$(make -s -f auto/configure-getcc.mk getcc)"
    mkld="$(make -s -f auto/configure-getcc.mk getld)"

    echo 'int add0(int x){ return x; }' > auto/configure-add0.c
    "$mkcc" -c auto/configure-add0.c -o auto/configure-add0.o

    for vendor in xpg8 apple binutils ; do
        eval candflags=\"'$dllflags_'$vendor\"
        rm -f auto/configure.${file_ext}

        if "$mkld" $candflags auto/configure-add0.o \
                   -o auto/configure.${file_ext} 2>/dev/null &&
                [ -f auto/configure.${file_ext} ] ; then
            dllflags="$candflags"
            break ; fi

        if [ "$candflags" = "-G" ] ; then continue ; fi

        rm -f auto/configure.${file_ext}
        candflags=""
        eval for opt in \$dllflags_$vendor \; do \
             candflags=\"\$candflags -Xlinker \$opt\" \; done

        if "$mkld" $candflags auto/configure-add0.o \
                   -o auto/configure.${file_ext} 2>/dev/null &&
                [ -f auto/configure.${file_ext} ] ; then
            dllflags="$candflags"
            break ; fi
    done

    if ! [ "$dllflags" ] ; then
        echo ERROR: Cannot determine flags for creating DLLs! >&2
        exit 1
    fi
fi

case "$file_ext" in
    so) file_ext='so.${ProductVer}' ;;
    dylib) file_ext='${ProductVer}.dylib' ;;
    *) echo ERROR: Unknown filename extension: "$file_ext"! >&2; exit 1 ;;
esac

{   printf '%s\n' "FILE_EXT = $file_ext" "DLLFLAGS = $dllflags"

    if [ "$ld" != '${LD}' ] ; then printf '%s\n' "LD = $ld" ; fi
    if [ "$cc" != '${CC}' ] ; then printf '%s\n' "CC = $cc" ; fi

    if [ "$with" ] ; then
        with="$(echo "$with" | tr [a-z] [A-Z])"
        printf '%s\n' \
               "OBJ_GROUP_WITH_ADDITIONAL = \\" \
               "OBJ_GROUP_${with}_ADDITIONAL" \
               "CFLAGS_GROUP_WITH = \\" \
               "CFLAGS_GROUP_${with}"
    fi

    for p in prefix exec_prefix libdir includedir ; do
        eval val=\"\$install_$p\"
        if [ "$val" ] ; then printf '%s\n' "$p = $val" ; fi
    done
} > inc-config.mk