crosstool-ng/scripts/build/cc/100-gcc.sh

# This file adds the function to build the gcc C compiler
# Copyright 2007 Yann E. MORIN
# Licensed under the GPL v2. See COPYING in the root of this package

# Download gcc
do_gcc_get() {
    local linaro_version=""
    local linaro_series=""

    if [ "${CT_CC_GCC_CUSTOM}" = "y" ]; then
        CT_GetCustom "gcc" "${CT_CC_GCC_VERSION}" "${CT_CC_GCC_CUSTOM_LOCATION}"
    else
        # Account for the Linaro versioning
        linaro_version="$( echo "${CT_CC_GCC_VERSION}"  \
                           |${sed} -r -e 's/^linaro-//;'   \
                         )"
        linaro_series="$( echo "${linaro_version}"      \
                          |${sed} -r -e 's/-.*//;'         \
                        )"

        # The official gcc hosts put gcc under a gcc/release/ directory,
        # whereas the mirrors put it in the gcc/ directory.
        # Also, Split out linaro mirrors, so that downloads happen faster.
        if [ x"${linaro_version}" = x"${CT_CC_GCC_VERSION}" ]; then
            CT_GetFile "gcc-${CT_CC_GCC_VERSION}"                                                   \
                       {http,ftp,https}://ftp.gnu.org/gnu/gcc/gcc-${CT_CC_GCC_VERSION} \
                       ftp://{gcc.gnu.org,sourceware.org}/pub/gcc/releases/gcc-${CT_CC_GCC_VERSION}
        else
            YYMM=`echo ${CT_CC_GCC_VERSION} |cut -d- -f3 |${sed} -e 's,^..,,'`
            CT_GetFile "gcc-${CT_CC_GCC_VERSION}"                                                               \
                       "http://launchpad.net/gcc-linaro/${linaro_series}/${linaro_version}/+download"       \
                       https://releases.linaro.org/${YYMM}/components/toolchain/gcc-linaro/${linaro_series} \
                       http://cbuild.validation.linaro.org/snapshots
        fi

    fi # ! custom location
    # Starting with GCC 4.3, ecj is used for Java, and will only be
    # built if the configure script finds ecj.jar at the top of the
    # GCC source tree, which will not be there unless we get it and
    # put it there ourselves
    if [ "${CT_CC_LANG_JAVA_USE_ECJ}" = "y" ]; then
        CT_GetFile ecj-latest .jar http://mirrors.kernel.org/sourceware/java/ \
                                   http://crosstool-ng.org/pub/java           \
                                   ftp://gcc.gnu.org/pub/java                 \
                                   ftp://sourceware.org/pub/java
    fi
}

# Extract gcc
do_gcc_extract() {
    # If using custom directory location, nothing to do
    if [ "${CT_CC_GCC_CUSTOM}" = "y"                    \
         -a -d "${CT_SRC_DIR}/gcc-${CT_CC_GCC_VERSION}" ]; then
        return 0
    fi

    CT_Extract "gcc-${CT_CC_GCC_VERSION}"
    CT_Patch "gcc" "${CT_CC_GCC_VERSION}"

    # Copy ecj-latest.jar to ecj.jar at the top of the GCC source tree
    if [ "${CT_CC_LANG_JAVA_USE_ECJ}" = "y"                     \
         -a ! -f "${CT_SRC_DIR}/gcc-${CT_CC_GCC_VERSION}/ecj.jar"   \
       ]; then
        CT_DoExecLog ALL cp -v "${CT_TARBALLS_DIR}/ecj-latest.jar" "${CT_SRC_DIR}/gcc-${CT_CC_GCC_VERSION}/ecj.jar"
    fi
}

#------------------------------------------------------------------------------
# This function builds up the set of languages to enable
# No argument expected, returns the comma-separated language list on stdout
cc_gcc_lang_list() {
    local lang_list

    lang_list="c"
    [ "${CT_CC_LANG_CXX}" = "y"      ] && lang_list+=",c++"
    [ "${CT_CC_LANG_FORTRAN}" = "y"  ] && lang_list+=",fortran"
    [ "${CT_CC_LANG_ADA}" = "y"      ] && lang_list+=",ada"
    [ "${CT_CC_LANG_JAVA}" = "y"     ] && lang_list+=",java"
    [ "${CT_CC_LANG_OBJC}" = "y"     ] && lang_list+=",objc"
    [ "${CT_CC_LANG_OBJCXX}" = "y"   ] && lang_list+=",obj-c++"
    [ "${CT_CC_LANG_GOLANG}" = "y"   ] && lang_list+=",go"
    lang_list+="${CT_CC_LANG_OTHERS:+,${CT_CC_LANG_OTHERS}}"

    printf "%s" "${lang_list}"
}

#------------------------------------------------------------------------------
# Core gcc pass 1
do_gcc_core_pass_1() {
    local -a core_opts

    if [ "${CT_CC_CORE_PASS_1_NEEDED}" != "y" ]; then
        return 0
    fi

    core_opts+=( "mode=static" )
    core_opts+=( "host=${CT_BUILD}" )
    core_opts+=( "complibs=${CT_BUILDTOOLS_PREFIX_DIR}" )
    core_opts+=( "prefix=${CT_BUILDTOOLS_PREFIX_DIR}" )
    core_opts+=( "cflags=${CT_CFLAGS_FOR_HOST}" )
    core_opts+=( "ldflags=${CT_LDFLAGS_FOR_HOST}" )
    core_opts+=( "lang_list=c" )

    CT_DoStep INFO "Installing pass-1 core C gcc compiler"
    CT_mkdir_pushd "${CT_BUILD_DIR}/build-cc-gcc-core-pass-1"

    do_gcc_core_backend "${core_opts[@]}"

    CT_Popd
    CT_EndStep
}

# Core gcc pass 2
do_gcc_core_pass_2() {
    local -a core_opts

    if [ "${CT_CC_CORE_PASS_2_NEEDED}" != "y" ]; then
        return 0
    fi

    # Common options:
    core_opts+=( "host=${CT_BUILD}" )
    core_opts+=( "prefix=${CT_BUILDTOOLS_PREFIX_DIR}" )
    core_opts+=( "complibs=${CT_BUILDTOOLS_PREFIX_DIR}" )
    core_opts+=( "cflags=${CT_CFLAGS_FOR_HOST}" )
    core_opts+=( "ldflags=${CT_LDFLAGS_FOR_HOST}" )
    core_opts+=( "lang_list=c" )

    # Different conditions are at stake here:
    #   - In case the threading model is NPTL, we need a shared-capable core
    #     gcc; in all other cases, we need a static-only core gcc.
    #   - In case the threading model is NPTL or win32, or gcc is 4.3 or
    #     later, we need to build libgcc
    case "${CT_THREADS}" in
        nptl)
            core_opts+=( "mode=shared" )
            core_opts+=( "build_libgcc=yes" )
            ;;
        win32)
            core_opts+=( "mode=static" )
            core_opts+=( "build_libgcc=yes" )
            ;;
        *)
            core_opts+=( "mode=static" )
            if [ "${CT_CC_GCC_4_3_or_later}" = "y" ]; then
                core_opts+=( "build_libgcc=yes" )
            fi
            ;;
    esac

    CT_DoStep INFO "Installing pass-2 core C gcc compiler"
    CT_mkdir_pushd "${CT_BUILD_DIR}/build-cc-gcc-core-pass-2"

    do_gcc_core_backend "${core_opts[@]}"

    CT_Popd
    CT_EndStep
}

#------------------------------------------------------------------------------
# Build core gcc
# This function is used to build the core C compiler.
# Usage: do_gcc_core_backend param=value [...]
#   Parameter           : Definition                                : Type      : Default
#   mode                : build a 'static', 'shared' or 'baremetal' : string    : (none)
#   host                : the machine the core will run on          : tuple     : (none)
#   prefix              : dir prefix to install into                : dir       : (none)
#   complibs            : dir where complibs are isntalled          : dir       : (none)
#   lang_list           : the list of languages to build            : string    : (empty)
#   build_libgcc        : build libgcc or not                       : bool      : no
#   build_libstdcxx     : build libstdc++ or not                    : bool      : no
#   build_libgfortran   : build libgfortran or not                  : bool      : no
#   build_staticlinked  : build statically linked or not            : bool      : no
#   build_manuals       : whether to build manuals or not           : bool      : no
#   cflags              : cflags to use                             : string    : (empty)
#   ldflags             : ldflags to use                            : string    : (empty)
# Usage: do_gcc_core_backend mode=[static|shared|baremetal] build_libgcc=[yes|no] build_staticlinked=[yes|no]
do_gcc_core_backend() {
    local mode
    local build_libgcc=no
    local build_libstdcxx=no
    local build_libgfortran=no
    local build_staticlinked=no
    local build_manuals=no
    local host
    local prefix
    local complibs
    local lang_list
    local cflags
    local ldflags
    local tmp
    local -a host_libstdcxx_flags
    local -a extra_config
    local -a core_LDFLAGS
    local -a core_targets
    local -a extra_user_config
    local arg

    for arg in "$@"; do
        eval "${arg// /\\ }"
    done

    CT_DoLog EXTRA "Configuring core C gcc compiler"

    case "${mode}" in
        static)
            extra_config+=("--with-newlib")
            extra_config+=("--enable-threads=no")
            extra_config+=("--disable-shared")
            extra_user_config=( "${CT_CC_CORE_EXTRA_CONFIG_ARRAY[@]}" )
            ;;
        shared)
            extra_config+=("--enable-shared")
            extra_user_config=( "${CT_CC_CORE_EXTRA_CONFIG_ARRAY[@]}" )
            ;;
        baremetal)
            extra_config+=("--with-newlib")
            extra_config+=("--enable-threads=no")
            extra_config+=("--disable-shared")
            extra_user_config=( "${CT_CC_EXTRA_CONFIG_ARRAY[@]}" )
            ;;
        *)
            CT_Abort "Internal Error: 'mode' must be one of: 'static', 'shared' or 'baremetal', not '${mode:-(empty)}'"
            ;;
    esac

    if [ "${CT_CC_GCC_HAS_PKGVERSION_BUGURL}" = "y" ]; then
        # Bare metal delivers the core compiler as final compiler, so add version info and bugurl
        extra_config+=("--with-pkgversion=${CT_PKGVERSION}")
        [ -n "${CT_TOOLCHAIN_BUGURL}" ] && extra_config+=("--with-bugurl=${CT_TOOLCHAIN_BUGURL}")
    fi

    CT_DoLog DEBUG "Copying headers to install area of core C compiler"
    CT_DoExecLog ALL cp -a "${CT_HEADERS_DIR}" "${prefix}/${CT_TARGET}/include"

    for tmp in ARCH ABI CPU TUNE FPU FLOAT; do
        eval tmp="\${CT_ARCH_WITH_${tmp}}"
        if [ -n "${tmp}" ]; then
            extra_config+=("${tmp}")
        fi
    done
    if [ "${CT_CC_CXA_ATEXIT}" = "y" ]; then
        extra_config+=("--enable-__cxa_atexit")
    else
        extra_config+=("--disable-__cxa_atexit")
    fi

    core_LDFLAGS+=("${ldflags}")

    # *** WARNING ! ***
    # Keep this full if-else-if-elif-fi-fi block in sync
    # with the same block in do_gcc, below.
    if [ "${build_staticlinked}" = "yes" ]; then
        core_LDFLAGS+=("-static")
        host_libstdcxx_flags+=("-static-libgcc")
        host_libstdcxx_flags+=("-Wl,-Bstatic,-lstdc++")
        host_libstdcxx_flags+=("-lm")
        # Companion libraries are build static (eg !shared), so
        # the libstdc++ is not pulled automatically, although it
        # is needed. Shoe-horn it in our LDFLAGS
        # Ditto libm on some Fedora boxen
        core_LDFLAGS+=("-lstdc++")
        core_LDFLAGS+=("-lm")
    else
        if [ "${CT_CC_GCC_STATIC_LIBSTDCXX}" = "y" ]; then
            # this is from CodeSourcery arm-2010q1-202-arm-none-linux-gnueabi.src.tar.bz2
            # build script
            # INFO: if the host gcc is gcc-4.5 then presumably we could use -static-libstdc++,
            #       see http://gcc.gnu.org/ml/gcc-patches/2009-06/msg01635.html
            host_libstdcxx_flags+=("-static-libgcc")
            host_libstdcxx_flags+=("-Wl,-Bstatic,-lstdc++,-Bdynamic")
            host_libstdcxx_flags+=("-lm")
        elif [ "${CT_COMPLIBS_SHARED}" != "y" ]; then
            # When companion libraries are build static (eg !shared),
            # the libstdc++ is not pulled automatically, although it
            # is needed. Shoe-horn it in our LDFLAGS
            # Ditto libm on some Fedora boxen
            core_LDFLAGS+=("-lstdc++")
            core_LDFLAGS+=("-lm")
        fi
    fi

    if [ "${CT_CC_GCC_USE_GMP_MPFR}" = "y" ]; then
        extra_config+=("--with-gmp=${complibs}")
        extra_config+=("--with-mpfr=${complibs}")
    fi
    if [ "${CT_CC_GCC_USE_MPC}" = "y" ]; then
        extra_config+=("--with-mpc=${complibs}")
    fi
    if [ "${CT_CC_GCC_USE_GRAPHITE}" = "y" ]; then
        if [ "${CT_PPL}" = "y" ]; then
            extra_config+=("--with-ppl=${complibs}")
            # With PPL 0.11+, also pull libpwl if needed
            if [ "${CT_PPL_NEEDS_LIBPWL}" = "y" ]; then
                host_libstdcxx_flags+=("-L${complibs}/lib")
                host_libstdcxx_flags+=("-lpwl")
            fi
        fi
        if [ "${CT_ISL}" = "y" ]; then
            extra_config+=("--with-isl=${complibs}")
        fi
        extra_config+=("--with-cloog=${complibs}")
    elif [ "${CT_CC_GCC_HAS_GRAPHITE}" = "y" ]; then
        extra_config+=("--with-ppl=no")
        extra_config+=("--with-isl=no")
        extra_config+=("--with-cloog=no")
    fi
    if [ "${CT_CC_GCC_USE_LTO}" = "y" ]; then
        extra_config+=("--with-libelf=${complibs}")
        extra_config+=("--enable-lto")
    elif [ "${CT_CC_GCC_HAS_LTO}" = "y" ]; then
        extra_config+=("--with-libelf=no")
        extra_config+=("--disable-lto")
    fi

    if [ ${#host_libstdcxx_flags[@]} -ne 0 ]; then
        extra_config+=("--with-host-libstdcxx=${host_libstdcxx_flags[*]}")
    fi

    if [ "${CT_CC_GCC_ENABLE_TARGET_OPTSPACE}" = "y" ]; then
        extra_config+=("--enable-target-optspace")
    fi

    case "${CT_CC_GCC_LDBL_128}" in
        y)  extra_config+=("--with-long-double-128");;
        m)  ;;
        "") extra_config+=("--without-long-double-128");;
    esac

    if [ "${CT_CC_GCC_BUILD_ID}" = "y" ]; then
        extra_config+=( --enable-linker-build-id )
    fi

    case "${CT_CC_GCC_LNK_HASH_STYLE}" in
        "") ;;
        *)  extra_config+=( "--with-linker-hash-style=${CT_CC_GCC_LNK_HASH_STYLE}" );;
    esac

    case "${CT_CC_GCC_DEC_FLOATS}" in
        "") ;;
        *)  extra_config+=( "--enable-decimal-float=${CT_CC_GCC_DEC_FLOATS}" );;
    esac

    case "${CT_ARCH}" in
        mips)
            case "${CT_CC_GCC_mips_llsc}" in
                y)  extra_config+=( --with-llsc );;
                m)  ;;
                *)  extra_config+=( --without-llsc );;
            esac
            case "${CT_CC_GCC_mips_synci}" in
                y)  extra_config+=( --with-synci );;
                m)  ;;
                *)  extra_config+=( --without-synci );;
            esac
            if [ "${CT_CC_GCC_mips_plt}" ]; then
                extra_config+=( --with-mips-plt )
            fi
            ;; # ARCH is mips
    esac

    extra_config+=(--disable-libgomp)
    extra_config+=(--disable-libmudflap)

    [ "${CT_TOOLCHAIN_ENABLE_NLS}" != "y" ] && extra_config+=("--disable-nls")

    [ "${CT_CC_GCC_DISABLE_PCH}" = "y" ] && extra_config+=("--disable-libstdcxx-pch")

    if [ "${CT_CC_GCC_SYSTEM_ZLIB}" = "y" ]; then
        extra_config+=("--with-system-zlib")
    fi

    # Some versions of gcc have a deffective --enable-multilib.
    # Since that's the default, only pass --disable-multilib.
    if [ "${CT_MULTILIB}" != "y" ]; then
        extra_config+=("--disable-multilib")
    fi

    CT_DoLog DEBUG "Extra config passed: '${extra_config[*]}'"

    # Use --with-local-prefix so older gccs don't look in /usr/local (http://gcc.gnu.org/PR10532)
    CT_DoExecLog CFG                                   \
    CC_FOR_BUILD="${CT_BUILD}-gcc"                     \
    CFLAGS="${cflags}"                                 \
    CXXFLAGS="${cflags}"                               \
    LDFLAGS="${core_LDFLAGS[*]}"                       \
    "${CT_SRC_DIR}/gcc-${CT_CC_GCC_VERSION}/configure" \
        --build=${CT_BUILD}                            \
        --host=${host}                                 \
        --target=${CT_TARGET}                          \
        --prefix="${prefix}"                           \
        --with-local-prefix="${CT_SYSROOT_DIR}"        \
        --disable-libmudflap                           \
        ${CC_CORE_SYSROOT_ARG}                         \
        "${extra_config[@]}"                           \
        --enable-languages="${lang_list}"              \
        "${extra_user_config[@]}"

    if [ "${build_libgcc}" = "yes" ]; then
        # HACK: we need to override SHLIB_LC from gcc/config/t-slibgcc-elf-ver or
        # gcc/config/t-libunwind so -lc is removed from the link for
        # libgcc_s.so, as we do not have a target -lc yet.
        # This is not as ugly as it appears to be ;-) All symbols get resolved
        # during the glibc build, and we provide a proper libgcc_s.so for the
        # cross toolchain during the final gcc build.
        #
        # As we cannot modify the source tree, nor override SHLIB_LC itself
        # during configure or make, we have to edit the resultant
        # gcc/libgcc.mk itself to remove -lc from the link.
        # This causes us to have to jump through some hoops...
        #
        # To produce libgcc.mk to edit we firstly require libiberty.a,
        # so we configure then build it.
        # Next we have to configure gcc, create libgcc.mk then edit it...
        # So much easier if we just edit the source tree, but hey...
        if [ ! -f "${CT_SRC_DIR}/gcc-${CT_CC_GCC_VERSION}/gcc/BASE-VER" ]; then
            CT_DoExecLog CFG make ${JOBSFLAGS} configure-libiberty
            CT_DoExecLog ALL make ${JOBSFLAGS} -C libiberty libiberty.a
            CT_DoExecLog CFG make ${JOBSFLAGS} configure-gcc configure-libcpp
            CT_DoExecLog ALL make ${JOBSFLAGS} all-libcpp
        else
            CT_DoExecLog CFG make ${JOBSFLAGS} configure-gcc configure-libcpp configure-build-libiberty
            CT_DoExecLog ALL make ${JOBSFLAGS} all-libcpp all-build-libiberty
        fi
        # HACK: gcc-4.2 uses libdecnumber to build libgcc.mk, so build it here.
        if [ -d "${CT_SRC_DIR}/gcc-${CT_CC_GCC_VERSION}/libdecnumber" ]; then
            CT_DoExecLog CFG make ${JOBSFLAGS} configure-libdecnumber
            CT_DoExecLog ALL make ${JOBSFLAGS} -C libdecnumber libdecnumber.a
        fi
        # HACK: gcc-4.8 uses libbacktrace to make libgcc.mvars, so make it here.
        if [ -d "${CT_SRC_DIR}/gcc-${CT_CC_GCC_VERSION}/libbacktrace" ]; then
            CT_DoExecLog CFG make ${JOBSFLAGS} configure-libbacktrace
            CT_DoExecLog ALL make ${JOBSFLAGS} -C libbacktrace
        fi

        # Starting with GCC 4.3, libgcc.mk is no longer built,
        # and libgcc.mvars is used instead.

        if [ "${CT_CC_GCC_4_3_or_later}" = "y" ]; then
            libgcc_rule="libgcc.mvars"
            core_targets=( gcc target-libgcc )
        else
            libgcc_rule="libgcc.mk"
            core_targets=( gcc )
        fi

        # On bare metal and canadian build the host-compiler is used when
        # actually the build-system compiler is required. Choose the correct
        # compilers for canadian build and use the defaults on other
        # configurations.
        if [ "${CT_BARE_METAL},${CT_CANADIAN}" = "y,y" ]; then
            repair_cc="CC_FOR_BUILD=${CT_BUILD}-gcc \
                       CXX_FOR_BUILD=${CT_BUILD}-g++ \
                       GCC_FOR_TARGET=${CT_TARGET}-gcc"
        else
            repair_cc=""
        fi

        CT_DoExecLog ALL make ${JOBSFLAGS} -C gcc ${libgcc_rule} \
                              ${repair_cc}
        sed -r -i -e 's@-lc@@g' gcc/${libgcc_rule}
    else # build_libgcc
        core_targets=( gcc )
    fi   # ! build libgcc
    if [    "${build_libstdcxx}" = "yes"    \
         -a "${CT_CC_LANG_CXX}"  = "y"      \
       ]; then
        core_targets+=( target-libstdc++-v3 )
    fi

    if [    "${build_libgfortran}" = "yes"    \
         -a "${CT_CC_LANG_FORTRAN}"  = "y"    \
       ]; then
        core_targets+=( target-libgfortran )
    fi

    CT_DoLog EXTRA "Building gcc"
    CT_DoExecLog ALL make ${JOBSFLAGS} "${core_targets[@]/#/all-}"

    CT_DoLog EXTRA "Installing gcc"
    CT_DoExecLog ALL make ${JOBSFLAGS} "${core_targets[@]/#/install-}"

    if [ "${build_manuals}" = "yes" ]; then
        CT_DoLog EXTRA "Building the GCC manuals"
        CT_DoExecLog ALL make pdf html
        CT_DoLog EXTRA "Installing the GCC manuals"
        CT_DoExecLog ALL make install-{pdf,html}-gcc
    fi

    # Create a symlink ${CT_TARGET}-cc to ${CT_TARGET}-gcc to always be able
    # to call the C compiler with the same, somewhat canonical name.
    # check whether compiler has an extension
    file="$( ls -1 "${prefix}/bin/${CT_TARGET}-gcc."* 2>/dev/null || true )"
    [ -z "${file}" ] || ext=".${file##*.}"
    if [ -f "${prefix}/bin/${CT_TARGET}-gcc${ext}" ]; then
        CT_DoExecLog ALL ln -sfv "${CT_TARGET}-gcc${ext}" "${prefix}/bin/${CT_TARGET}-cc${ext}"
    fi

    if [ "${CT_MULTILIB}" = "y" ]; then
        if [ "${CT_CANADIAN}" = "y" -a "${mode}" = "baremetal" \
             -a "${host}" = "${CT_HOST}" ]; then
            CT_DoLog WARN "Canadian Cross unable to confirm multilibs configured correctly"
        else
            multilibs=( $( "${prefix}/bin/${CT_TARGET}-gcc" -print-multi-lib   \
                           |tail -n +2 ) )
            if [ ${#multilibs[@]} -ne 0 ]; then
                CT_DoLog EXTRA "gcc configured with these multilibs (besides the default):"
                for i in "${multilibs[@]}"; do
                    dir="${i%%;*}"
                    flags="${i#*;}"
                    CT_DoLog EXTRA "   ${flags//@/ -}  -->  ${dir}/"
                done
            else
                CT_DoLog WARN "gcc configured for multilib, but none available"
           fi
        fi
    fi
}

#------------------------------------------------------------------------------
# Build complete gcc to run on build
do_gcc_for_build() {
    local -a build_final_opts
    local build_final_backend

    # In case we're canadian or cross-native, it seems that a
    # real, complete compiler is needed?!? WTF? Sigh...
    # Otherwise, there is nothing to do.
    case "${CT_TOOLCHAIN_TYPE}" in
        native|cross)   return 0;;
    esac

    build_final_opts+=( "host=${CT_BUILD}" )
    build_final_opts+=( "prefix=${CT_BUILDTOOLS_PREFIX_DIR}" )
    build_final_opts+=( "complibs=${CT_BUILDTOOLS_PREFIX_DIR}" )
    build_final_opts+=( "lang_list=$( cc_gcc_lang_list )" )
    if [ "${CT_BARE_METAL}" = "y" ]; then
        # In the tests I've done, bare-metal was not impacted by the
        # lack of such a compiler, but better safe than sorry...
        build_final_opts+=( "mode=baremetal" )
        build_final_opts+=( "build_libgcc=yes" )
        build_final_opts+=( "build_libstdcxx=yes" )
        build_final_opts+=( "build_libgfortran=yes" )
        if [ "${CT_STATIC_TOOLCHAIN}" = "y" ]; then
            build_final_opts+=( "build_staticlinked=yes" )
        fi
        build_final_backend=do_gcc_core_backend
    else
        build_final_backend=do_gcc_backend
    fi

    CT_DoStep INFO "Installing final gcc compiler for build"
    CT_mkdir_pushd "${CT_BUILD_DIR}/build-cc-gcc-final-build-${CT_BUILD}"

    "${build_final_backend}" "${build_final_opts[@]}"

    CT_Popd
    CT_EndStep
}

#------------------------------------------------------------------------------
# Build final gcc to run on host
do_gcc_for_host() {
    local -a final_opts
    local final_backend

    final_opts+=( "host=${CT_HOST}" )
    final_opts+=( "prefix=${CT_PREFIX_DIR}" )
    final_opts+=( "complibs=${CT_HOST_COMPLIBS_DIR}" )
    final_opts+=( "cflags=${CT_CFLAGS_FOR_HOST}" )
    final_opts+=( "ldflags=${CT_LDFLAGS_FOR_HOST}" )
    final_opts+=( "lang_list=$( cc_gcc_lang_list )" )
    if [ "${CT_BUILD_MANUALS}" = "y" ]; then
        final_opts+=( "build_manuals=yes" )
    fi
    if [ "${CT_BARE_METAL}" = "y" ]; then
        final_opts+=( "mode=baremetal" )
        final_opts+=( "build_libgcc=yes" )
        final_opts+=( "build_libstdcxx=yes" )
        final_opts+=( "build_libgfortran=yes" )
        if [ "${CT_STATIC_TOOLCHAIN}" = "y" ]; then
            final_opts+=( "build_staticlinked=yes" )
        fi
        final_backend=do_gcc_core_backend
    else
        final_backend=do_gcc_backend
    fi

    CT_DoStep INFO "Installing final gcc compiler"
    CT_mkdir_pushd "${CT_BUILD_DIR}/build-cc-gcc-final"

    "${final_backend}" "${final_opts[@]}"

    CT_Popd
    CT_EndStep
}

#------------------------------------------------------------------------------
# Build the final gcc
# Usage: do_gcc_backend param=value [...]
#   Parameter     : Definition                          : Type      : Default
#   host          : the host we run onto                : tuple     : (none)
#   prefix        : the runtime prefix                  : dir       : (none)
#   complibs      : the companion libraries prefix      : dir       : (none)
#   cflags        : cflags to use                       : string    : (empty)
#   ldflags       : ldflags to use                      : string    : (empty)
#   lang_list     : the list of languages to build      : string    : (empty)
#   build_manuals : whether to build manuals or not     : bool      : no
do_gcc_backend() {
    local host
    local prefix
    local complibs
    local cflags
    local ldflags
    local lang_list
    local build_manuals
    local -a host_libstdcxx_flags
    local -a extra_config
    local -a final_LDFLAGS
    local tmp
    local arg

    for arg in "$@"; do
        eval "${arg// /\\ }"
    done

    CT_DoLog EXTRA "Configuring final gcc compiler"

    # Enable selected languages
    extra_config+=("--enable-languages=${lang_list}")

    for tmp in ARCH ABI CPU TUNE FPU FLOAT; do
        eval tmp="\${CT_ARCH_WITH_${tmp}}"
        if [ -n "${tmp}" ]; then
            extra_config+=("${tmp}")
        fi
    done

    [ "${CT_SHARED_LIBS}" = "y" ] || extra_config+=("--disable-shared")
    if [ "${CT_CC_GCC_HAS_PKGVERSION_BUGURL}" = "y" ]; then
        extra_config+=("--with-pkgversion=${CT_PKGVERSION}")
        [ -n "${CT_TOOLCHAIN_BUGURL}" ] && extra_config+=("--with-bugurl=${CT_TOOLCHAIN_BUGURL}")
    fi
    case "${CT_CC_GCC_SJLJ_EXCEPTIONS}" in
        y)  extra_config+=("--enable-sjlj-exceptions");;
        m)  ;;
        "") extra_config+=("--disable-sjlj-exceptions");;
    esac
    if [ "${CT_CC_CXA_ATEXIT}" = "y" ]; then
        extra_config+=("--enable-__cxa_atexit")
    else
        extra_config+=("--disable-__cxa_atexit")
    fi
    if [ -n "${CT_CC_GCC_ENABLE_CXX_FLAGS}" ]; then
        extra_config+=("--enable-cxx-flags=${CT_CC_GCC_ENABLE_CXX_FLAGS}")
    fi
    if [ "${CT_CC_GCC_4_8_or_later}" = "y" ]; then
        if [ "${CT_THREADS}" = "none" ]; then
            extra_config+=(--disable-libatomic)
        fi
    fi
    if [ "${CT_CC_GCC_LIBMUDFLAP}" = "y" ]; then
        extra_config+=(--enable-libmudflap)
    else
        extra_config+=(--disable-libmudflap)
    fi
    if [ "${CT_CC_GCC_LIBGOMP}" = "y" ]; then
        extra_config+=(--enable-libgomp)
    else
        extra_config+=(--disable-libgomp)
    fi
    if [ "${CT_CC_GCC_LIBSSP}" = "y" ]; then
        extra_config+=(--enable-libssp)
    else
        extra_config+=(--disable-libssp)
    fi
    if [ "${CT_CC_GCC_HAS_LIBQUADMATH}" = "y" ]; then
        if [ "${CT_CC_GCC_LIBQUADMATH}" = "y" ]; then
            extra_config+=(--enable-libquadmath)
            extra_config+=(--enable-libquadmath-support)
        else
            extra_config+=(--disable-libquadmath)
            extra_config+=(--disable-libquadmath-support)
        fi
    fi
    if [ "${CT_CC_GCC_HAS_LIBSANITIZER}" = "y" ]; then
        if [ "${CT_CC_GCC_LIBSANITIZER}" = "y" ]; then
            extra_config+=(--enable-libsanitizer)
        else
            extra_config+=(--disable-libsanitizer)
        fi
    fi

    final_LDFLAGS+=("${ldflags}")

    # *** WARNING ! ***
    # Keep this full if-else-if-elif-fi-fi block in sync
    # with the same block in do_gcc_core, above.
    if [ "${CT_STATIC_TOOLCHAIN}" = "y" ]; then
        final_LDFLAGS+=("-static")
        host_libstdcxx_flags+=("-static-libgcc")
        host_libstdcxx_flags+=("-Wl,-Bstatic,-lstdc++")
        host_libstdcxx_flags+=("-lm")
        # Companion libraries are build static (eg !shared), so
        # the libstdc++ is not pulled automatically, although it
        # is needed. Shoe-horn it in our LDFLAGS
        # Ditto libm on some Fedora boxen
        final_LDFLAGS+=("-lstdc++")
        final_LDFLAGS+=("-lm")
    else
        if [ "${CT_CC_GCC_STATIC_LIBSTDCXX}" = "y" ]; then
            # this is from CodeSourcery arm-2010q1-202-arm-none-linux-gnueabi.src.tar.bz2
            # build script
            # INFO: if the host gcc is gcc-4.5 then presumably we could use -static-libstdc++,
            #       see http://gcc.gnu.org/ml/gcc-patches/2009-06/msg01635.html
            host_libstdcxx_flags+=("-static-libgcc")
            host_libstdcxx_flags+=("-Wl,-Bstatic,-lstdc++,-Bdynamic")
            host_libstdcxx_flags+=("-lm")
        elif [ "${CT_COMPLIBS_SHARED}" != "y" ]; then
            # When companion libraries are build static (eg !shared),
            # the libstdc++ is not pulled automatically, although it
            # is needed. Shoe-horn it in our LDFLAGS
            # Ditto libm on some Fedora boxen
            final_LDFLAGS+=("-lstdc++")
            final_LDFLAGS+=("-lm")
        fi
    fi

    if [ "${CT_CC_GCC_USE_GMP_MPFR}" = "y" ]; then
        extra_config+=("--with-gmp=${complibs}")
        extra_config+=("--with-mpfr=${complibs}")
    fi
    if [ "${CT_CC_GCC_USE_MPC}" = "y" ]; then
        extra_config+=("--with-mpc=${complibs}")
    fi
    if [ "${CT_CC_GCC_USE_GRAPHITE}" = "y" ]; then
        if [ "${CT_PPL}" = "y" ]; then
            extra_config+=("--with-ppl=${complibs}")
            # With PPL 0.11+, also pull libpwl if needed
            if [ "${CT_PPL_NEEDS_LIBPWL}" = "y" ]; then
                host_libstdcxx_flags+=("-L${complibs}/lib")
                host_libstdcxx_flags+=("-lpwl")
            fi
        fi
        if [ "${CT_ISL}" = "y" ]; then
            extra_config+=("--with-isl=${complibs}")
        fi
        extra_config+=("--with-cloog=${complibs}")
    elif [ "${CT_CC_GCC_HAS_GRAPHITE}" = "y" ]; then
        extra_config+=("--with-ppl=no")
        extra_config+=("--with-isl=no")
        extra_config+=("--with-cloog=no")
    fi
    if [ "${CT_CC_GCC_USE_LTO}" = "y" ]; then
        extra_config+=("--with-libelf=${complibs}")
    elif [ "${CT_CC_GCC_HAS_LTO}" = "y" ]; then
        extra_config+=("--with-libelf=no")
    fi

    if [ ${#host_libstdcxx_flags[@]} -ne 0 ]; then
        extra_config+=("--with-host-libstdcxx=${host_libstdcxx_flags[*]}")
    fi

    if [ "${CT_THREADS}" = "none" ]; then
        extra_config+=("--disable-threads")
        if [ "${CT_CC_GCC_4_2_or_later}" = y ]; then
            CT_Test "Disabling libgomp for no-thread gcc>=4.2" "${CT_CC_GCC_LIBGOMP}" = "Y"
            extra_config+=("--disable-libgomp")
        fi
    else
        if [ "${CT_THREADS}" = "win32" ]; then
            extra_config+=("--enable-threads=win32")
            extra_config+=("--disable-win32-registry")
        else
            extra_config+=("--enable-threads=posix")
        fi
    fi

    if [ "${CT_CC_GCC_ENABLE_TARGET_OPTSPACE}" = "y" ]; then
        extra_config+=("--enable-target-optspace")
    fi
    if [ "${CT_CC_GCC_DISABLE_PCH}" = "y" ]; then
        extra_config+=("--disable-libstdcxx-pch")
    fi

    case "${CT_CC_GCC_LDBL_128}" in
        y)  extra_config+=("--with-long-double-128");;
        m)  ;;
        "") extra_config+=("--without-long-double-128");;
    esac

    if [ "${CT_CC_GCC_BUILD_ID}" = "y" ]; then
        extra_config+=( --enable-linker-build-id )
    fi

    case "${CT_CC_GCC_LNK_HASH_STYLE}" in
        "") ;;
        *)  extra_config+=( "--with-linker-hash-style=${CT_CC_GCC_LNK_HASH_STYLE}" );;
    esac

    case "${CT_CC_GCC_DEC_FLOATS}" in
        "") ;;
        *)  extra_config+=( "--enable-decimal-float=${CT_CC_GCC_DEC_FLOATS}" );;
    esac

    if [ "${CT_CC_GCC_ENABLE_PLUGINS}" = "y" ]; then
        extra_config+=( --enable-plugin )
    fi
    if [ "${CT_CC_GCC_GOLD}" = "y" ]; then
        extra_config+=( --enable-gold )
    fi

    case "${CT_ARCH}" in
        mips)
            case "${CT_CC_GCC_mips_llsc}" in
                y)  extra_config+=( --with-llsc );;
                m)  ;;
                *)  extra_config+=( --without-llsc );;
            esac
            case "${CT_CC_GCC_mips_synci}" in
                y)  extra_config+=( --with-synci );;
                m)  ;;
                *)  extra_config+=( --without-synci );;
            esac
            if [ "${CT_CC_GCC_mips_plt}" ]; then
                extra_config+=( --with-mips-plt )
            fi
            ;; # ARCH is mips
    esac

    [ "${CT_TOOLCHAIN_ENABLE_NLS}" != "y" ] && extra_config+=("--disable-nls")

    if [ "${CT_CC_GCC_SYSTEM_ZLIB}" = "y" ]; then
        extra_config+=("--with-system-zlib")
    fi


    # Some versions of gcc have a deffective --enable-multilib.
    # Since that's the default, only pass --disable-multilib.
    if [ "${CT_MULTILIB}" != "y" ]; then
        extra_config+=("--disable-multilib")
    fi

    CT_DoLog DEBUG "Extra config passed: '${extra_config[*]}'"

    CT_DoExecLog CFG                                \
    CC_FOR_BUILD="${CT_BUILD}-gcc"                  \
    CFLAGS="${cflags}"                              \
    CXXFLAGS="${cflags}"                            \
    LDFLAGS="${final_LDFLAGS[*]}"                   \
    CFLAGS_FOR_TARGET="${CT_TARGET_CFLAGS}"         \
    CXXFLAGS_FOR_TARGET="${CT_TARGET_CFLAGS}"       \
    LDFLAGS_FOR_TARGET="${CT_TARGET_LDFLAGS}"       \
    "${CT_SRC_DIR}/gcc-${CT_CC_GCC_VERSION}/configure" \
        --build=${CT_BUILD}                         \
        --host=${host}                              \
        --target=${CT_TARGET}                       \
        --prefix="${prefix}"                        \
        ${CC_SYSROOT_ARG}                           \
        "${extra_config[@]}"                        \
        --with-local-prefix="${CT_SYSROOT_DIR}"     \
        --enable-long-long                          \
        "${CT_CC_GCC_EXTRA_CONFIG_ARRAY[@]}"

    if [ "${CT_CANADIAN}" = "y" ]; then
        CT_DoLog EXTRA "Building libiberty"
        CT_DoExecLog ALL make ${JOBSFLAGS} all-build-libiberty
    fi

    CT_DoLog EXTRA "Building final gcc compiler"
    CT_DoExecLog ALL make ${JOBSFLAGS} all

    CT_DoLog EXTRA "Installing final gcc compiler"
    CT_DoExecLog ALL make ${JOBSFLAGS} install

    if [ "${build_manuals}" = "yes" ]; then
        CT_DoLog EXTRA "Building the GCC manuals"
        CT_DoExecLog ALL make pdf html
        CT_DoLog EXTRA "Installing the GCC manuals"
        CT_DoExecLog ALL make install-{pdf,html}-gcc
    fi

    # Create a symlink ${CT_TARGET}-cc to ${CT_TARGET}-gcc to always be able
    # to call the C compiler with the same, somewhat canonical name.
    # check whether compiler has an extension
    file="$( ls -1 "${CT_PREFIX_DIR}/bin/${CT_TARGET}-gcc."* 2>/dev/null || true )"
    [ -z "${file}" ] || ext=".${file##*.}"
    if [ -f "${CT_PREFIX_DIR}/bin/${CT_TARGET}-gcc${ext}" ]; then
        CT_DoExecLog ALL ln -sfv "${CT_TARGET}-gcc${ext}" "${CT_PREFIX_DIR}/bin/${CT_TARGET}-cc${ext}"
    fi

    if [ "${CT_MULTILIB}" = "y" ]; then
        if [ "${CT_CANADIAN}" = "y" ]; then
            CT_DoLog WARN "Canadian Cross unable to confirm multilibs configured correctly"
        else
            multilibs=( $( "${prefix}/bin/${CT_TARGET}-gcc" -print-multi-lib \
                           |tail -n +2 ) )
            if [ ${#multilibs[@]} -ne 0 ]; then
                CT_DoLog EXTRA "gcc configured with these multilibs (besides the default):"
                for i in "${multilibs[@]}"; do
                    dir="${i%%;*}"
                    flags="${i#*;}"
                    CT_DoLog EXTRA "   ${flags//@/ -}  -->  ${dir}/"
                done
            else
                CT_DoLog WARN "gcc configured for multilib, but none available"
            fi
        fi
    fi
}