# This file contains some usefull common functions
# Copyright 2007 Yann E. MORIN
# Licensed under the GPL v2. See COPYING in the root of this package

# Prepare the fault handler
CT_OnError() {
    ret=$?
    # Bail out early in subshell, the upper level shell will act accordingly.
    [ ${BASH_SUBSHELL} -eq 0 ] || exit $ret
    CT_DoLog ERROR "Build failed in step '${CT_STEP_MESSAGE[${CT_STEP_COUNT}]}'"
    for((step=(CT_STEP_COUNT-1); step>1; step--)); do
        CT_DoLog ERROR "      called in step '${CT_STEP_MESSAGE[${step}]}'"
    done
    CT_DoLog ERROR "Error happened in '${BASH_SOURCE[1]}' in function '${FUNCNAME[1]}' (line unknown, sorry)"
    for((depth=2; ${BASH_LINENO[$((${depth}-1))]}>0; depth++)); do
        CT_DoLog ERROR "      called from '${BASH_SOURCE[${depth}]}' at line # ${BASH_LINENO[${depth}-1]} in function '${FUNCNAME[${depth}]}'"
    done
    [ "${CT_LOG_TO_FILE}" = "y" ] && CT_DoLog ERROR "Look at '${CT_LOG_FILE}' for more info on this error."
    CT_STEP_COUNT=1
    CT_DoEnd ERROR
    exit $ret
}

# Install the fault handler
trap CT_OnError ERR

# Inherit the fault handler in subshells and functions
set -E

# Make pipes fail on the _first_ failed command
# Not supported on bash < 3.x, but we need it, so drop the obsoleting bash-2.x
set -o pipefail

# Don't hash commands' locations, and search every time it is requested.
# This is slow, but needed because of the static/shared core gcc which shall
# always match to shared if it exists, and only fallback to static if the
# shared is not found
set +o hashall

# Log policy:
#  - first of all, save stdout so we can see the live logs: fd #6
exec 6>&1
#  - then point stdout to the log file (temporary for now)
tmp_log_file="${CT_TOP_DIR}/log.$$"
exec >>"${tmp_log_file}"

# The different log levels:
CT_LOG_LEVEL_ERROR=0
CT_LOG_LEVEL_WARN=1
CT_LOG_LEVEL_INFO=2
CT_LOG_LEVEL_EXTRA=3
CT_LOG_LEVEL_DEBUG=4
CT_LOG_LEVEL_ALL=5

# A function to log what is happening
# Different log level are available:
#   - ERROR:   A serious, fatal error occurred
#   - WARN:    A non fatal, non serious error occurred, take your responsbility with the generated build
#   - INFO:    Informational messages
#   - EXTRA:   Extra informational messages
#   - DEBUG:   Debug messages
#   - ALL:     Component's build messages
# Usage: CT_DoLog <level> [message]
# If message is empty, then stdin will be logged.
CT_DoLog() {
    local max_level LEVEL level cur_l cur_L
    local l
    eval max_level="\${CT_LOG_LEVEL_${CT_LOG_LEVEL_MAX}}"
    # Set the maximum log level to DEBUG if we have none
    [ -z "${max_level}" ] && max_level=${CT_LOG_LEVEL_DEBUG}

    LEVEL="$1"; shift
    eval level="\${CT_LOG_LEVEL_${LEVEL}}"

    if [ $# -eq 0 ]; then
        cat -
    else
        echo "${@}"
    fi |( IFS="\n" # We want the full lines, even leading spaces
          _prog_bar_cpt=0
          _prog_bar[0]='/'
          _prog_bar[1]='-'
          _prog_bar[2]='\'
          _prog_bar[3]='|'
          indent=$((2*CT_STEP_COUNT))
          while read line; do
              case "${CT_LOG_SEE_TOOLS_WARN},${line}" in
                y,*"warning:"*)         cur_L=WARN; cur_l=${CT_LOG_LEVEL_WARN};;
                y,*"WARNING:"*)         cur_L=WARN; cur_l=${CT_LOG_LEVEL_WARN};;
                *"error:"*)             cur_L=ERROR; cur_l=${CT_LOG_LEVEL_ERROR};;
                *"make["*"]: *** ["*)   cur_L=ERROR; cur_l=${CT_LOG_LEVEL_ERROR};;
                *)                      cur_L="${LEVEL}"; cur_l="${level}";;
              esac
              # There will always be a log file (stdout, fd #1), be it /dev/null
              printf "[%-5s]%*s%s%s\n" "${cur_L}" "${indent}" " " "${line}"
              if [ ${cur_l} -le ${max_level} ]; then
                  # Only print to console (fd #6) if log level is high enough.
                  printf "\r[%-5s]%*s%s%s\n" "${cur_L}" "${indent}" " " "${line}" >&6
              fi
              if [ "${CT_LOG_PROGRESS_BAR}" = "y" ]; then
                  printf "\r[%02d:%02d] %s " $((SECONDS/60)) $((SECONDS%60)) "${_prog_bar[$((_prog_bar_cpt/10))]}" >&6
                  _prog_bar_cpt=$(((_prog_bar_cpt+1)%40))
              fi
          done
        )

    return 0
}

# Execute an action, and log its messages
# Usage: CT_DoExecLog <level> <[VAR=val...] command [parameters...]>
CT_DoExecLog() {
    local level="$1"
    shift
    CT_DoLog DEBUG "==> Executing: '${@}'"
    "${@}" 2>&1 |CT_DoLog "${level}"
}

# Tail message to be logged whatever happens
# Usage: CT_DoEnd <level>
CT_DoEnd()
{
    local level="$1"
    CT_STOP_DATE=$(CT_DoDate +%s%N)
    CT_STOP_DATE_HUMAN=$(CT_DoDate +%Y%m%d.%H%M%S)
    if [ "${level}" != "ERROR" ]; then
        CT_DoLog "${level:-INFO}" "Build completed at ${CT_STOP_DATE_HUMAN}"
    fi
    elapsed=$((CT_STOP_DATE-CT_STAR_DATE))
    elapsed_min=$((elapsed/(60*1000*1000*1000)))
    elapsed_sec=$(printf "%02d" $(((elapsed%(60*1000*1000*1000))/(1000*1000*1000))))
    elapsed_csec=$(printf "%02d" $(((elapsed%(1000*1000*1000))/(10*1000*1000))))
    CT_DoLog ${level:-INFO} "(elapsed: ${elapsed_min}:${elapsed_sec}.${elapsed_csec})"
}

# Abort the execution with an error message
# Usage: CT_Abort <message>
CT_Abort() {
    CT_DoLog ERROR "$1"
    exit 1
}

# Test a condition, and print a message if satisfied
# Usage: CT_Test <message> <tests>
CT_Test() {
    local ret
    local m="$1"
    shift
    test "$@" && CT_DoLog WARN "$m"
    return 0
}

# Test a condition, and abort with an error message if satisfied
# Usage: CT_TestAndAbort <message> <tests>
CT_TestAndAbort() {
    local m="$1"
    shift
    test "$@" && CT_Abort "$m"
    return 0
}

# Test a condition, and abort with an error message if not satisfied
# Usage: CT_TestAndAbort <message> <tests>
CT_TestOrAbort() {
    local m="$1"
    shift
    test "$@" || CT_Abort "$m"
    return 0
}

# Test the presence of a tool, or abort if not found
# Usage: CT_HasOrAbort <tool>
CT_HasOrAbort() {
    CT_TestAndAbort "'${1}' not found and needed for successful toolchain build." -z "$(CT_Which "${1}")"
    return 0
}

# Search a program: wrap "which" for those system where
# "which" verbosely says there is no match (Mdk are such
# suckers...)
# Usage: CT_Which <filename>
CT_Which() {
  which "$1" 2>/dev/null || true
}

# Get current date with nanosecond precision
# On those system not supporting nanosecond precision, faked with rounding down
# to the highest entire second
# Usage: CT_DoDate <fmt>
CT_DoDate() {
    date "$1" |sed -r -e 's/%N$/000000000/;'
}

CT_STEP_COUNT=1
CT_STEP_MESSAGE[${CT_STEP_COUNT}]="<none>"
# Memorise a step being done so that any error is caught
# Usage: CT_DoStep <loglevel> <message>
CT_DoStep() {
    local start=$(CT_DoDate +%s%N)
    CT_DoLog "$1" "================================================================="
    CT_DoLog "$1" "$2"
    CT_STEP_COUNT=$((CT_STEP_COUNT+1))
    CT_STEP_LEVEL[${CT_STEP_COUNT}]="$1"; shift
    CT_STEP_START[${CT_STEP_COUNT}]="${start}"
    CT_STEP_MESSAGE[${CT_STEP_COUNT}]="$1"
    return 0
}

# End the step just being done
# Usage: CT_EndStep
CT_EndStep() {
    local stop=$(CT_DoDate +%s%N)
    local duration=$(printf "%032d" $((stop-${CT_STEP_START[${CT_STEP_COUNT}]})) |sed -r -e 's/([[:digit:]]{2})[[:digit:]]{7}$/\.\1/; s/^0+//; s/^\./0\./;')
    local elapsed=$(printf "%02d:%02d" $((SECONDS/60)) $((SECONDS%60)))
    local level="${CT_STEP_LEVEL[${CT_STEP_COUNT}]}"
    local message="${CT_STEP_MESSAGE[${CT_STEP_COUNT}]}"
    CT_STEP_COUNT=$((CT_STEP_COUNT-1))
    CT_DoLog "${level}" "${message}: done in ${duration}s (at ${elapsed})"
    return 0
}

# Pushes into a directory, and pops back
CT_Pushd() {
    pushd "$1" >/dev/null 2>&1
}
CT_Popd() {
    popd >/dev/null 2>&1
}

# Makes a path absolute
# Usage: CT_MakeAbsolutePath path
CT_MakeAbsolutePath() {
    # Try to cd in that directory
    if [ -d "$1" ]; then
        CT_Pushd "$1"
        pwd
        CT_Popd
    else
        # No such directory, fail back to guessing
        case "$1" in
            /*)  echo "$1";;
            *)   echo "$(pwd)/$1";;
        esac
    fi
    
    return 0
}

# Creates a temporary directory
# $1: variable to assign to
# Usage: CT_MktempDir foo
CT_MktempDir() {
    # Some mktemp do not allow more than 6 Xs
    eval "$1"=$(mktemp -q -d "${CT_BUILD_DIR}/.XXXXXX")
    CT_TestOrAbort "Could not make temporary directory" -n "${!1}" -a -d "${!1}"
    CT_DoLog DEBUG "Made temporary directory '${!1}'"
    return 0
}

# Echoes the specified string on stdout until the pipe breaks.
# Doesn't fail
# $1: string to echo
# Usage: CT_DoYes "" |make oldconfig
CT_DoYes() {
    yes "$1" || true
}

# Get the file name extension of a component
# Usage: CT_GetFileExtension <component_name-component_version> [extension]
# If found, echoes the extension to stdout
# If not found, echoes nothing on stdout.
CT_GetFileExtension() {
    local ext
    local file="$1"
    shift
    local first_ext="$1"

    CT_Pushd "${CT_TARBALLS_DIR}"
    # we need to also check for an empty extension for those very
    # peculiar components that don't have one (such as sstrip from
    # buildroot).
    for ext in ${first_ext} .tar.gz .tar.bz2 .tgz .tar ''; do
        if [ -f "${file}${ext}" ]; then
            echo "${ext}"
            break
        fi
    done
    CT_Popd

    return 0
}

# Set environment for proxy access
# Usage: CT_DoSetProxy <proxy_type>
# where proxy_type is one of 'http', 'sockssys', 'socks4' or 'socks5',
# or empty (to not change proxy settings).
CT_DoSetProxy() {
    case "${1}" in
        http)
            http_proxy="http://"
            case  "${CT_PROXY_USER}:${CT_PROXY_PASS}" in
                :)      ;;
                :*)     http_proxy="${http_proxy}:${CT_PROXY_PASS}@";;
                *:)     http_proxy="${http_proxy}${CT_PROXY_USER}@";;
                *:*)    http_proxy="${http_proxy}${CT_PROXY_USER}:${CT_PROXY_PASS}@";;
            esac
            export http_proxy="${http_proxy}${CT_PROXY_HOST}:${CT_PROXY_PORT}/"
            export https_proxy="${http_proxy}"
            export ftp_proxy="${http_proxy}"
            CT_DoLog DEBUG "http_proxy='${http_proxy}'"
            ;;
        sockssys)
            CT_HasOrAbort tsocks
            . tsocks -on
            ;;
        socks*)
            # Remove any lingering config file from any previous run
            rm -f "${CT_BUILD_DIR}/tsocks.conf"
            # Find all interfaces and build locally accessible networks
            server_ip=$(ping -c 1 -W 2 "${CT_PROXY_HOST}" |head -n 1 |sed -r -e 's/^[^\(]+\(([^\)]+)\).*$/\1/;' || true)
            CT_TestOrAbort "SOCKS proxy '${CT_PROXY_HOST}' has no IP." -n "${server_ip}"
            /sbin/ifconfig |gawk -v server_ip="${server_ip}" '
                BEGIN {
                    split( server_ip, tmp, "\\." );
                    server_ip_num = tmp[1] * 2^24 + tmp[2] * 2^16 + tmp[3] * 2^8 + tmp[4] * 2^0;
                    pairs = 0;
                }

                $0 ~ /^[[:space:]]*inet addr:/ {
                    split( $2, tmp, ":|\\." );
                    if( ( tmp[2] == 127 ) && ( tmp[3] == 0 ) && ( tmp[4] == 0 ) && ( tmp[5] == 1 ) ) {
                        /* Skip 127.0.0.1, it'\''s taken care of by tsocks itself */
                        next;
                    }
                    ip_num = tmp[2] * 2^24 + tmp[3] * 2^16 + tmp[4] * 2 ^8 + tmp[5] * 2^0;
                    i = 32;
                    do {
                        i--;
                        mask = 2^32 - 2^i;
                    } while( (i!=0) && ( and( server_ip_num, mask ) == and( ip_num, mask ) ) );
                    mask = and( 0xFFFFFFFF, lshift( mask, 1 ) );
                    if( (i!=0) && (mask!=0) ) {
                        masked_ip = and( ip_num, mask );
                        for( i=0; i<pairs; i++ ) {
                            if( ( masked_ip == ips[i] ) && ( mask == masks[i] ) ) {
                                next;
                            }
                        }
                        ips[pairs] = masked_ip;
                        masks[pairs] = mask;
                        pairs++;
                        printf( "local = %d.%d.%d.%d/%d.%d.%d.%d\n",
                                and( 0xFF, masked_ip / 2^24 ),
                                and( 0xFF, masked_ip / 2^16 ),
                                and( 0xFF, masked_ip / 2^8 ),
                                and( 0xFF, masked_ip / 2^0 ),
                                and( 0xFF, mask / 2^24 ),
                                and( 0xFF, mask / 2^16 ),
                                and( 0xFF, mask / 2^8 ),
                                and( 0xFF, mask / 2^0 ) );
                    }
                }
            ' >"${CT_BUILD_DIR}/tsocks.conf"
            ( echo "server = ${server_ip}";
              echo "server_port = ${CT_PROXY_PORT}";
              [ -n "${CT_PROXY_USER}"   ] && echo "default_user=${CT_PROXY_USER}";
              [ -n "${CT_PROXY_PASS}" ] && echo "default_pass=${CT_PROXY_PASS}";
            ) >>"${CT_BUILD_DIR}/tsocks.conf"
            case "${CT_PROXY_TYPE/socks}" in
                4|5) proxy_type="${CT_PROXY_TYPE/socks}";;
                auto)
                    reply=$(inspectsocks "${server_ip}" "${CT_PROXY_PORT}" 2>&1 || true)
                    case "${reply}" in
                        *"server is a version 4 socks server") proxy_type=4;;
                        *"server is a version 5 socks server") proxy_type=5;;
                        *) CT_Abort "Unable to determine SOCKS proxy type for '${CT_PROXY_HOST}:${CT_PROXY_PORT}'"
                    esac
                    ;;
            esac
            echo "server_type = ${proxy_type}" >> "${CT_BUILD_DIR}/tsocks.conf"
            CT_HasOrAbort tsocks
            # If tsocks was found, then validateconf is present (distributed with tsocks).
            CT_DoExecLog DEBUG validateconf -f "${CT_BUILD_DIR}/tsocks.conf"
            export TSOCKS_CONF_FILE="${CT_BUILD_DIR}/tsocks.conf"
            . tsocks -on
            ;;
    esac
}

# Download an URL using wget
# Usage: CT_DoGetFileWget <URL>
CT_DoGetFileWget() {
    # Need to return true because it is legitimate to not find the tarball at
    # some of the provided URLs (think about snapshots, different layouts for
    # different gcc versions, etc...)
    # Some (very old!) FTP server might not support the passive mode, thus
    # retry without
    # With automated download as we are doing, it can be very dangerous to use
    # -c to continue the downloads. It's far better to simply overwrite the
    # destination file
    # Some company networks have firewalls to connect to the internet, but it's
    # not easy to detect them, and wget does not timeout by default  while
    # connecting, so force a global ${CT_CONNECT_TIMEOUT}-second timeout.
    wget -T ${CT_CONNECT_TIMEOUT} -nc --progress=dot:binary --tries=3 --passive-ftp "$1"    \
    || wget -T ${CT_CONNECT_TIMEOUT} -nc --progress=dot:binary --tries=3 "$1"               \
    || true
}

# Download an URL using curl
# Usage: CT_DoGetFileCurl <URL>
CT_DoGetFileCurl() {
    # Note: comments about wget method (above) are also valid here
    # Plus: no good progress indicator is available with curl,
    #       so output is consigned to oblivion
    curl --ftp-pasv -O --retry 3 "$1" --connect-timeout ${CT_CONNECT_TIMEOUT} >/dev/null    \
    || curl -O --retry 3 "$1" --connect-timeout ${CT_CONNECT_TIMEOUT} >/dev/null            \
    || true
}

_wget=$(CT_Which wget)
_curl=$(CT_Which curl)
# Wrapper function to call one of curl or wget
# Usage: CT_DoGetFile <URL>
CT_DoGetFile() {
    case "${_wget},${_curl}" in
        ,)  CT_DoError "Could find neither wget nor curl";;
        ,*) CT_DoExecLog ALL CT_DoGetFileCurl "$1" 2>&1;;
        *)  CT_DoExecLog ALL CT_DoGetFileWget "$1" 2>&1;;
    esac
}

# Download the file from one of the URLs passed as argument
# Usage: CT_GetFile <filename> [extension] <url> [url ...]
CT_GetFile() {
    local ext
    local url
    local file="$1"
    local first_ext=""
    shift
    # If next argument starts with a dot, then this is not an URL,
    # and we can consider that it is a preferred extension.
    case "$1" in
        .*) first_ext="$1"
            shift
            ;;
    esac

    # Do we already have it?
    ext=$(CT_GetFileExtension "${file}" ${first_ext})
    if [ -n "${ext}" ]; then
        CT_DoLog DEBUG "Already have '${file}'"
        return 0
    fi

    # Try to retrieve the file
    CT_DoLog EXTRA "Retrieving '${file}'"
    CT_Pushd "${CT_TARBALLS_DIR}"

    if [ -n "${CT_LOCAL_TARBALLS_DIR}" ]; then
        CT_DoLog DEBUG "Trying to retrieve an already downloaded copy of '${file}'"
        # We'd rather have a bzip2'ed tarball, then gzipped tarball, plain tarball,
        # or, as a failover, a file without extension.
        # Try local copy first, if it exists
        for ext in ${first_ext} .tar.bz2 .tar.gz .tgz .tar ''; do
            CT_DoLog DEBUG "Trying '${CT_LOCAL_TARBALLS_DIR}/${file}${ext}'"
            if [ -r "${CT_LOCAL_TARBALLS_DIR}/${file}${ext}" -a \
                 "${CT_FORCE_DOWNLOAD}" != "y" ]; then
                CT_DoLog DEBUG "Got '${file}' from local storage"
                CT_DoExecLog ALL ln -s "${CT_LOCAL_TARBALLS_DIR}/${file}${ext}" "${file}${ext}"
                return 0
            fi
        done
    fi

    # Not found locally, try from the network

    # Add URLs on the LAN mirror
    LAN_URLS=
    if [ "${CT_USE_MIRROR}" = "y" ]; then
        CT_DoLog DEBUG "Trying to retrieve a copy of '${file}' from LAN mirror '${CT_MIRROR_HOSTNAME}'"
        CT_TestOrAbort "Please set the LAN mirror hostname" -n "${CT_MIRROR_HOSTNAME}"
        CT_TestOrAbort "Please tell me where to find tarballs on the LAN mirror '${CT_MIRROR_HOSTNAME}'" -n "${CT_MIRROR_BASE}"
        LAN_URLS="${LAN_URLS} ${CT_MIRROR_SCHEME}://${CT_MIRROR_HOSTNAME}/${CT_MIRROR_BASE}/${file%-*}"
        LAN_URLS="${LAN_URLS} ${CT_MIRROR_SCHEME}://${CT_MIRROR_HOSTNAME}/${CT_MIRROR_BASE}"
    fi

    if [ "${CT_PREFER_MIRROR}" = "y" ]; then
        URLS="${LAN_URLS} ${@}"
    else
        URLS="${@} ${LAN_URLS}"
    fi

    # Scan all URLs in turn, and try to grab a tarball from there
    CT_DoSetProxy ${CT_PROXY_TYPE}
    for ext in ${first_ext} .tar.bz2 .tar.gz .tgz .tar ''; do
        # Try all urls in turn
        for url in ${URLS}; do
            CT_DoLog DEBUG "Trying '${url}/${file}${ext}'"
            CT_DoGetFile "${url}/${file}${ext}"
            if [ -f "${file}${ext}" ]; then
                CT_DoLog DEBUG "Got '${file}' from the Internet"
                if [ "${CT_SAVE_TARBALLS}" = "y" ]; then
                    # The file may already exist if downloads are forced: remove it first
                    CT_DoLog EXTRA "Saving '${file}' to local storage"
                    CT_DoExecLog ALL rm -f "${CT_LOCAL_TARBALLS_DIR}/${file}${ext}"
                    CT_DoExecLog ALL mv -f "${file}${ext}" "${CT_LOCAL_TARBALLS_DIR}"
                    CT_DoExecLog ALL ln -s "${CT_LOCAL_TARBALLS_DIR}/${file}${ext}" "${file}${ext}"
                fi
                return 0
            fi
        done
    done
    CT_Popd

    CT_Abort "Could not retrieve '${file}'."
}

# Extract a tarball and patch the resulting sources if necessary.
# Some tarballs need to be extracted in specific places. Eg.: glibc addons
# must be extracted in the glibc directory; uCLibc locales must be extracted
# in the extra/locale sub-directory of uClibc.
CT_ExtractAndPatch() {
    local file="$1"
    local base_file=$(echo "${file}" |cut -d - -f 1)
    local ver_file=$(echo "${file}" |cut -d - -f 2-)
    local official_patch_dir
    local custom_patch_dir
    local libc_addon
    local ext=$(CT_GetFileExtension "${file}")
    CT_TestAndAbort "'${file}' not found in '${CT_TARBALLS_DIR}'" -z "${ext}"
    local full_file="${CT_TARBALLS_DIR}/${file}${ext}"

    CT_Pushd "${CT_SRC_DIR}"

    # Add-ons need a little love, really.
    case "${file}" in
        glibc-[a-z]*-*|eglibc-[a-z]*-*)
            CT_TestAndAbort "Trying to extract the C-library addon/locales '${file}' when C-library not yet extracted" ! -d "${CT_LIBC_FILE}"
            cd "${CT_LIBC_FILE}"
            libc_addon=y
            [ -f ".${file}.extracted" ] && return 0
            touch ".${file}.extracted"
            ;;
        uClibc-locale-*)
            CT_TestAndAbort "Trying to extract the C-library addon/locales '${file}' when C-library not yet extracted" ! -d "${CT_LIBC_FILE}"
            cd "${CT_LIBC_FILE}/extra/locale"
            libc_addon=y
            [ -f ".${file}.extracted" ] && return 0
            touch ".${file}.extracted"
            ;;
    esac

    # If the directory exists, then consider extraction and patching done
    if [ -d "${file}" ]; then
        CT_DoLog DEBUG "Already extracted '${file}'"
        return 0
    fi

    CT_DoLog EXTRA "Extracting and patching '${file}'"
    case "${ext}" in
        .tar.bz2)     CT_DoExecLog ALL tar xvjf "${full_file}";;
        .tar.gz|.tgz) CT_DoExecLog ALL tar xvzf "${full_file}";;
        .tar)         CT_DoExecLog ALL tar xvf  "${full_file}";;
        *)            CT_Abort "Don't know how to handle '${file}': unknown extension" ;;
    esac

    # Snapshots might not have the version number in the extracted directory
    # name. This is also the case for some (odd) packages, such as D.U.M.A.
    # Overcome this issue by symlink'ing the directory.
    if [ ! -d "${file}" -a "${libc_addon}" != "y" ]; then
        case "${ext}" in
            .tar.bz2)     base=$(tar tjf "${full_file}" |head -n 1 |cut -d / -f 1 || true);;
            .tar.gz|.tgz) base=$(tar tzf "${full_file}" |head -n 1 |cut -d / -f 1 || true);;
            .tar)         base=$(tar tf  "${full_file}" |head -n 1 |cut -d / -f 1 || true);;
        esac
        CT_TestOrAbort "There was a problem when extracting '${file}'" -d "${base}" -o "${base}" != "${file}"
        ln -s "${base}" "${file}"
    fi

    # Kludge: outside this function, we wouldn't know if we had just extracted
    # a libc addon, or a plain package. Apply patches now.
    if [ "${libc_addon}" = "y" ]; then
        # Some addon tarballs directly contain the correct addon directory,
        # while others have the addon directory named after the tarball.
        # Fix that by always using the short name (eg: linuxthreads, ports, etc...)
        addon_short_name=$(echo "${file}" |sed -r -e 's/^[^-]+-([^-]+)-.*$/\1/;')
        if [ ! -d "${addon_short_name}" ]; then
            mv "${file}" "${addon_short_name}"
            # Keep a symlink to avoid re-extracting later on.
            ln -s "${addon_short_name}" "${file}"
        fi
        # If libc addon, we're already in the correct place
    else
        cd "${file}"
    fi

    official_patch_dir=
    custom_patch_dir=
    [ "${CT_CUSTOM_PATCH_ONLY}" = "y" ] || official_patch_dir="${CT_LIB_DIR}/patches/${base_file}/${ver_file}"
    [ "${CT_CUSTOM_PATCH}" = "y" ] && custom_patch_dir="${CT_CUSTOM_PATCH_DIR}/${base_file}/${ver_file}"
    for patch_dir in "${official_patch_dir}" "${custom_patch_dir}"; do
        if [ -n "${patch_dir}" -a -d "${patch_dir}" ]; then
            for p in "${patch_dir}"/*.patch; do
                if [ -f "${p}" ]; then
                    CT_DoLog DEBUG "Applying patch '${p}'"
                    CT_DoExecLog ALL patch -g0 -F1 -p1 -f <"${p}"
                    CT_TestAndAbort "Failed while applying patch file '${p}'" ${PIPESTATUS[0]} -ne 0
                fi
            done
        fi
    done

    if [ "${CT_OVERIDE_CONFIG_GUESS_SUB}" = "y" ]; then
        CT_DoLog ALL "Overiding config.guess and config.sub"
        for cfg in config_guess config_sub; do
            eval ${cfg}="${CT_LIB_DIR}/tools/${cfg/_/.}"
            [ -e "${CT_TOP_DIR}/tools/${cfg/_/.}" ] && eval ${cfg}="${CT_TOP_DIR}/tools/${cfg/_/.}"
            # Can't use CT_DoExecLog because of the '{} \;' to be passed un-mangled to find
            find . -type f -name "${cfg/_/.}" -exec cp -v "${!cfg}" {} \; |CT_DoLog ALL
        done
    fi

    CT_Popd
}

# Two wrappers to call config.(guess|sub) either from CT_TOP_DIR or CT_LIB_DIR.
# Those from CT_TOP_DIR, if they exist, will be be more recent than those from CT_LIB_DIR.
CT_DoConfigGuess() {
    if [ -x "${CT_TOP_DIR}/tools/config.guess" ]; then
        "${CT_TOP_DIR}/tools/config.guess"
    else
        "${CT_LIB_DIR}/tools/config.guess"
    fi
}

CT_DoConfigSub() {
    if [ -x "${CT_TOP_DIR}/tools/config.sub" ]; then
        "${CT_TOP_DIR}/tools/config.sub" "$@"
    else
        "${CT_LIB_DIR}/tools/config.sub" "$@"
    fi
}

# Compute the target tuple from what is provided by the user
# Usage: CT_DoBuildTargetTuple
# In fact this function takes the environment variables to build the target
# tuple. It is needed both by the normal build sequence, as well as the
# sample saving sequence.
CT_DoBuildTargetTuple() {
    # Set the endianness suffix, and the default endianness gcc option
    case "${CT_ARCH_BE},${CT_ARCH_LE}" in
        y,) target_endian_eb=eb
            target_endian_el=
            CT_ARCH_ENDIAN_CFLAG="-mbig-endian"
            CT_ARCH_ENDIAN_LDFLAG="-EB"
            ;;
        ,y) target_endian_eb=
            target_endian_el=el
            CT_ARCH_ENDIAN_CFLAG="-mlittle-endian"
            CT_ARCH_ENDIAN_LDFLAG="-EL"
            ;;
    esac

    # Build the default architecture tuple part
    CT_TARGET_ARCH="${CT_ARCH}"

    # Set defaults for the system part of the tuple. Can be overriden
    # by architecture-specific values.
    case "${CT_LIBC}" in
        none)   CT_TARGET_SYS=elf;;
        *glibc) CT_TARGET_SYS=gnu;;
        uClibc) CT_TARGET_SYS=uclibc;;
    esac

    # Transform the ARCH into a kernel-understandable ARCH
    CT_KERNEL_ARCH="${CT_ARCH}"

    # Set the default values for ARCH, ABI, CPU, TUNE, FPU and FLOAT
    unset CT_ARCH_ARCH_CFLAG CT_ARCH_ABI_CFLAG CT_ARCH_CPU_CFLAG CT_ARCH_TUNE_CFLAG CT_ARCH_FPU_CFLAG CT_ARCH_FLOAT_CFLAG
    unset CT_ARCH_WITH_ARCH CT_ARCH_WITH_ABI CT_ARCH_WITH_CPU CT_ARCH_WITH_TUNE CT_ARCH_WITH_FPU CT_ARCH_WITH_FLOAT
    [ "${CT_ARCH_ARCH}"     ] && { CT_ARCH_ARCH_CFLAG="-march=${CT_ARCH_ARCH}";  CT_ARCH_WITH_ARCH="--with-arch=${CT_ARCH_ARCH}"; }
    [ "${CT_ARCH_ABI}"      ] && { CT_ARCH_ABI_CFLAG="-mabi=${CT_ARCH_ABI}";     CT_ARCH_WITH_ABI="--with-abi=${CT_ARCH_ABI}";    }
    [ "${CT_ARCH_CPU}"      ] && { CT_ARCH_CPU_CFLAG="-mcpu=${CT_ARCH_CPU}";     CT_ARCH_WITH_CPU="--with-cpu=${CT_ARCH_CPU}";    }
    [ "${CT_ARCH_TUNE}"     ] && { CT_ARCH_TUNE_CFLAG="-mtune=${CT_ARCH_TUNE}";  CT_ARCH_WITH_TUNE="--with-tune=${CT_ARCH_TUNE}"; }
    [ "${CT_ARCH_FPU}"      ] && { CT_ARCH_FPU_CFLAG="-mfpu=${CT_ARCH_FPU}";     CT_ARCH_WITH_FPU="--with-fpu=${CT_ARCH_FPU}";    }
    [ "${CT_ARCH_FLOAT_SW}" ] && { CT_ARCH_FLOAT_CFLAG="-msoft-float";           CT_ARCH_WITH_FLOAT="--with-float=soft";          }

    # Build the default kernel tuple part
    CT_TARGET_KERNEL="${CT_KERNEL}"

    # Overide the default values with the components specific settings
    CT_DoArchTupleValues
    CT_DoKernelTupleValues

    # Finish the target tuple construction
    CT_TARGET=$(CT_DoConfigSub "${CT_TARGET_ARCH}-${CT_TARGET_VENDOR:-unknown}-${CT_TARGET_KERNEL}${CT_TARGET_KERNEL:+-}${CT_TARGET_SYS}")

    # Prepare the target CFLAGS
    CT_ARCH_TARGET_CFLAGS="${CT_ARCH_TARGET_CFLAGS} ${CT_ARCH_ENDIAN_CFLAG}"
    CT_ARCH_TARGET_CFLAGS="${CT_ARCH_TARGET_CFLAGS} ${CT_ARCH_ARCH_CFLAG}"
    CT_ARCH_TARGET_CFLAGS="${CT_ARCH_TARGET_CFLAGS} ${CT_ARCH_ABI_CFLAG}"
    CT_ARCH_TARGET_CFLAGS="${CT_ARCH_TARGET_CFLAGS} ${CT_ARCH_CPU_CFLAG}"
    CT_ARCH_TARGET_CFLAGS="${CT_ARCH_TARGET_CFLAGS} ${CT_ARCH_TUNE_CFLAG}"
    CT_ARCH_TARGET_CFLAGS="${CT_ARCH_TARGET_CFLAGS} ${CT_ARCH_FPU_CFLAG}"
    CT_ARCH_TARGET_CFLAGS="${CT_ARCH_TARGET_CFLAGS} ${CT_ARCH_FLOAT_CFLAG}"

    # Now on for the target LDFLAGS
    CT_ARCH_TARGET_LDFLAGS="${CT_ARCH_TARGET_LDFLAGS} ${CT_ARCH_ENDIAN_LDFLAG}"
}

# This function does pause the build until the user strikes "Return"
# Usage: CT_DoPause [optional_message]
CT_DoPause() {
    local foo
    local message="${1:-Pausing for your pleasure}"
    CT_DoLog INFO "${message}"
    read -p "Press 'Enter' to continue, or Ctrl-C to stop..." foo >&6
    return 0
}

# This function saves the state of the toolchain to be able to restart
# at any one point
# Usage: CT_DoSaveState <next_step_name>
CT_DoSaveState() {
	[ "${CT_DEBUG_CT_SAVE_STEPS}" = "y" ] || return 0
    local state_name="$1"
    local state_dir="${CT_STATE_DIR}/${state_name}"

    CT_DoLog DEBUG "Saving state to restart at step '${state_name}'..."
    rm -rf "${state_dir}"
    mkdir -p "${state_dir}"

    case "${CT_DEBUG_CT_SAVE_STEPS_GZIP}" in
        y)  tar_opt=z; tar_ext=.gz;;
        *)  tar_opt=;  tar_ext=;;
    esac

    CT_DoLog DEBUG "  Saving environment and aliases"
    # We must omit shell functions, and some specific bash variables
    # that break when restoring the environment, later. We could do
    # all the processing in the gawk script, but a sed is easier...
    set |gawk '
              BEGIN { _p = 1; }
              $0~/^[^ ]+ \(\)/ { _p = 0; }
              _p == 1
              $0 == "}" { _p = 1; }
              ' |sed -r -e '/^BASH_(ARGC|ARGV|LINENO|SOURCE|VERSINFO)=/d;
                           /^(UID|EUID)=/d;
                           /^(FUNCNAME|GROUPS|PPID|SHELLOPTS)=/d;' >"${state_dir}/env.sh"

    CT_DoLog DEBUG "  Saving CT_CC_CORE_STATIC_PREFIX_DIR='${CT_CC_CORE_STATIC_PREFIX_DIR}'"
    CT_Pushd "${CT_CC_CORE_STATIC_PREFIX_DIR}"
    CT_DoExecLog DEBUG tar cv${tar_opt}f "${state_dir}/cc_core_static_prefix_dir.tar${tar_ext}" .
    CT_Popd

    CT_DoLog DEBUG "  Saving CT_CC_CORE_SHARED_PREFIX_DIR='${CT_CC_CORE_SHARED_PREFIX_DIR}'"
    CT_Pushd "${CT_CC_CORE_SHARED_PREFIX_DIR}"
    CT_DoExecLog DEBUG tar cv${tar_opt}f "${state_dir}/cc_core_shared_prefix_dir.tar${tar_ext}" .
    CT_Popd

    CT_DoLog DEBUG "  Saving CT_PREFIX_DIR='${CT_PREFIX_DIR}'"
    CT_Pushd "${CT_PREFIX_DIR}"
    CT_DoExecLog DEBUG tar cv${tar_opt}f "${state_dir}/prefix_dir.tar${tar_ext}" --exclude '*.log' .
    CT_Popd

    if [ "${CT_LOG_TO_FILE}" = "y" ]; then
        CT_DoLog DEBUG "  Saving log file"
        exec >/dev/null
        case "${CT_DEBUG_CT_SAVE_STEPS_GZIP}" in
            y)  gzip -3 -c "${CT_LOG_FILE}"  >"${state_dir}/log.gz";;
            *)  cat "${CT_LOG_FILE}" >"${state_dir}/log";;
        esac
        exec >>"${CT_LOG_FILE}"
    fi
}

# This function restores a previously saved state
# Usage: CT_DoLoadState <state_name>
CT_DoLoadState(){
    local state_name="$1"
    local state_dir="${CT_STATE_DIR}/${state_name}"
    local old_RESTART="${CT_RESTART}"
    local old_STOP="${CT_STOP}"

    CT_TestOrAbort "The previous build did not reach the point where it could be restarted at '${CT_RESTART}'" -d "${state_dir}"

    # We need to do something special with the log file!
    if [ "${CT_LOG_TO_FILE}" = "y" ]; then
        exec >"${state_dir}/tail.log"
    fi
    CT_DoLog INFO "Restoring state at step '${state_name}', as requested."

    case "${CT_DEBUG_CT_SAVE_STEPS_GZIP}" in
        y)  tar_opt=z; tar_ext=.gz;;
        *)  tar_opt=;  tar_ext=;;
    esac

    CT_DoLog DEBUG "  Removing previous build directories"
    chmod -R u+rwX "${CT_PREFIX_DIR}" "${CT_CC_CORE_SHARED_PREFIX_DIR}" "${CT_CC_CORE_STATIC_PREFIX_DIR}"
    rm -rf         "${CT_PREFIX_DIR}" "${CT_CC_CORE_SHARED_PREFIX_DIR}" "${CT_CC_CORE_STATIC_PREFIX_DIR}"
    mkdir -p       "${CT_PREFIX_DIR}" "${CT_CC_CORE_SHARED_PREFIX_DIR}" "${CT_CC_CORE_STATIC_PREFIX_DIR}"

    CT_DoLog DEBUG "  Restoring CT_PREFIX_DIR='${CT_PREFIX_DIR}'"
    CT_Pushd "${CT_PREFIX_DIR}"
    CT_DoExecLog DEBUG tar xv${tar_opt}f "${state_dir}/prefix_dir.tar${tar_ext}"
    CT_Popd

    CT_DoLog DEBUG "  Restoring CT_CC_CORE_SHARED_PREFIX_DIR='${CT_CC_CORE_SHARED_PREFIX_DIR}'"
    CT_Pushd "${CT_CC_CORE_SHARED_PREFIX_DIR}"
    CT_DoExecLog DEBUG tar xv${tar_opt}f "${state_dir}/cc_core_shared_prefix_dir.tar${tar_ext}"
    CT_Popd

    CT_DoLog DEBUG "  Restoring CT_CC_CORE_STATIC_PREFIX_DIR='${CT_CC_CORE_STATIC_PREFIX_DIR}'"
    CT_Pushd "${CT_CC_CORE_STATIC_PREFIX_DIR}"
    CT_DoExecLog DEBUG tar xv${tar_opt}f "${state_dir}/cc_core_static_prefix_dir.tar${tar_ext}"
    CT_Popd

    # Restore the environment, discarding any error message
    # (for example, read-only bash internals)
    CT_DoLog DEBUG "  Restoring environment"
    . "${state_dir}/env.sh" >/dev/null 2>&1 || true

    # Restore the new RESTART and STOP steps
    CT_RESTART="${old_RESTART}"
    CT_STOP="${old_STOP}"
    unset old_stop old_restart

    if [ "${CT_LOG_TO_FILE}" = "y" ]; then
        CT_DoLog DEBUG "  Restoring log file"
        exec >/dev/null
        case "${CT_DEBUG_CT_SAVE_STEPS_GZIP}" in
            y)  zcat "${state_dir}/log.gz" >"${CT_LOG_FILE}";;
            *)  cat "${state_dir}/log" >"${CT_LOG_FILE}";;
        esac
        cat "${state_dir}/tail.log" >>"${CT_LOG_FILE}"
        exec >>"${CT_LOG_FILE}"
        rm -f "${state_dir}/tail.log"
    fi
}