scripts/build/libc/glibc-eglibc.sh-common
author "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Wed Nov 23 00:11:36 2011 +0100 (2011-11-23)
changeset 2825 1c5ca9b0a5a0
parent 2824 53d0a288209d
child 2826 4a21f0eb8b57
permissions -rw-r--r--
libc/glibc: add multilib-cacpable backend

For mutlilib, the C library must be built once for each variants.
Special care must be taken to put the resulting libraries in
the proper places.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
     1 # This file contains the functions common to glibc and eglibc
     2 
     3 # Extract the C library tarball(s)
     4 do_libc_extract() {
     5     local addon
     6 
     7     # Extract the main tarball
     8     CT_Extract "${CT_LIBC}-${CT_LIBC_VERSION}"
     9     CT_Pushd "${CT_SRC_DIR}/${CT_LIBC}-${CT_LIBC_VERSION}"
    10     CT_Patch nochdir "${CT_LIBC}" "${CT_LIBC_VERSION}"
    11 
    12     # Extract the add-opns
    13     for addon in $(do_libc_add_ons_list " "); do
    14         # If the addon was bundled with the main archive, we do not
    15         # need to extract it. Worse, if we were to try to extract
    16         # it, we'd get an error.
    17         if [ -d "${addon}" ]; then
    18             CT_DoLog DEBUG "Add-on already present, spkipping extraction"
    19             continue
    20         fi
    21 
    22         CT_Extract nochdir "${CT_LIBC}-${addon}-${CT_LIBC_VERSION}"
    23 
    24         CT_TestAndAbort "Error in add-on '${addon}': both short and long names in tarball" \
    25             -d "${addon}" -a -d "${CT_LIBC}-${addon}-${CT_LIBC_VERSION}"
    26 
    27         # Some addons have the 'long' name, while others have the
    28         # 'short' name, but patches are non-uniformly built with
    29         # either the 'long' or 'short' name, whatever the addons name
    30         # but we prefer the 'short' name and avoid duplicates.
    31         if [ -d "${CT_LIBC}-${addon}-${CT_LIBC_VERSION}" ]; then
    32             CT_DoExecLog FILE mv "${CT_LIBC}-${addon}-${CT_LIBC_VERSION}" "${addon}"
    33         fi
    34 
    35         CT_DoExecLog FILE ln -s "${addon}" "${CT_LIBC}-${addon}-${CT_LIBC_VERSION}"
    36 
    37         CT_Patch nochdir "${CT_LIBC}" "${addon}-${CT_LIBC_VERSION}"
    38 
    39         # Remove the long name since it can confuse configure scripts to run
    40         # the same source twice.
    41         rm "${CT_LIBC}-${addon}-${CT_LIBC_VERSION}"
    42     done
    43 
    44     # The configure files may be older than the configure.in files
    45     # if using a snapshot (or even some tarballs). Fake them being
    46     # up to date.
    47     find . -type f -name configure -exec touch {} \; 2>&1 |CT_DoLog ALL
    48 
    49     CT_Popd
    50 
    51     if [ "${CT_LIBC_LOCALES}" = "y" ]; then
    52         do_libc_locales_extract
    53     fi
    54 }
    55 
    56 # Build and install headers and start files
    57 do_libc_start_files() {
    58     # Start files and Headers should be configured the same way as the
    59     # final libc, but built and installed differently.
    60     do_libc_backend libc_mode=startfiles
    61 }
    62 
    63 # This function builds and install the full C library
    64 do_libc() {
    65     do_libc_backend libc_mode=final
    66 }
    67 
    68 # This backend builds the C library once for each multilib
    69 # variant the compiler gives us
    70 # Usage: do_libc_backend param=value [...]
    71 #   Parameter           : Definition                            : Type      : Default
    72 #   libc_mode           : 'startfiles' or 'final'               : string    : (none)
    73 do_libc_backend() {
    74     local libc_mode
    75     local -a multilibs
    76     local multilib
    77     local multi_dir
    78     local multi_flags
    79     local extra_dir
    80     local arg f fn ln pre
    81 
    82     for arg in "$@"; do
    83         eval "${arg// /\\ }"
    84     done
    85 
    86     case "${libc_mode}" in
    87         startfiles) CT_DoStep INFO "Installing C library headers & start files";;
    88         final)      CT_DoStep INFO "Installing C library";;
    89         *)          CT_Abort "Unsupported (or unset) libc_mode='${libc_mode}'";;
    90     esac
    91 
    92     # If gcc is not configured for multilib, it still prints
    93     # a single line for the default settings
    94     multilibs=( $("${CT_TARGET}-gcc" -print-multi-lib 2>/dev/null) )
    95     for multilib in "${multilibs[@]}"; do
    96         multi_dir="${multilib%%;*}"
    97         if [ "${multi_dir}" != "." ]; then
    98             CT_DoStep INFO "Building for multilib subdir='${multi_dir}'"
    99 
   100             extra_flags="$( echo "${multilib#*;}"       \
   101                             |${sed} -r -e 's/@/ -/g;'   \
   102                           )"
   103             extra_dir="/${multi_dir}"
   104 
   105             # glibc install its files in ${extra_dir}/{usr/,}lib
   106             # while gcc expects them in {,usr/}lib/${extra_dir}.
   107             # Prepare some symlinks so glibc installs in fact in
   108             # the proper place
   109             # We do it in the start-files step, so it is not needed
   110             # to do it in the final step, as the symlinks will
   111             # already exist
   112             if [ "${libc_mode}" = "startfiles" ]; then
   113                 CT_Pushd "${CT_SYSROOT_DIR}"
   114                 CT_DoExecLog ALL mkdir -p "lib/${multi_dir}"        \
   115                                           "usr/lib/${multi_dir}"    \
   116                                           "${multi_dir}"            \
   117                                           "${multi_dir}/usr"
   118                 CT_DoExecLog ALL ln -sf "../lib/${multi_dir}" "${multi_dir}/lib"
   119                 CT_DoExecLog ALL ln -sf "../../usr/lib/${multi_dir}" "${multi_dir}/usr/lib"
   120                 CT_Popd
   121             fi
   122         else
   123             extra_dir=
   124             extra_flags=
   125         fi
   126 
   127         mkdir -p "${CT_BUILD_DIR}/build-libc-${libc_mode}${extra_dir//\//_}"
   128         CT_Pushd "${CT_BUILD_DIR}/build-libc-${libc_mode}${extra_dir//\//_}"
   129 
   130         do_libc_backend_once extra_dir="${extra_dir}"      \
   131                              extra_flags="${extra_flags}"   \
   132                              "$@"
   133 
   134         CT_Popd
   135 
   136         if [ "${multi_dir}" != "." ]; then
   137             if [ "${libc_mode}" = "final" ]; then
   138                 CT_DoLog EXTRA "Fixing up multilib location"
   139 
   140                 # rewrite the library multiplexers
   141                 for d in "lib/${multi_dir}" "usr/lib/${multi_dir}"; do
   142                     for l in libc libpthread libgcc_s; do
   143                         if [    -f "${CT_SYSROOT_DIR}/${d}/${l}.so"    \
   144                              -a ! -L ${CT_SYSROOT_DIR}/${d}/${l}.so    ]
   145                         then
   146                             CT_DoExecLog DEBUG ${sed} -r -i                                 \
   147                                                       -e "s:/lib/:/lib/${multi_dir}/:g;"    \
   148                                                       "${CT_SYSROOT_DIR}/${d}/${l}.so"
   149                         fi
   150                     done
   151                 done
   152             fi # libc_mode == final
   153             CT_EndStep
   154         fi
   155     done
   156 
   157     CT_EndStep
   158 }
   159 
   160 # This backend builds the C library once
   161 # Usage: do_libc_backend_once param=value [...]
   162 #   Parameter           : Definition                            : Type      : Default
   163 #   libc_mode           : 'startfiles' or 'final'               : string    : (none)
   164 #   extra_flags         : Extra CFLAGS to use (for multilib)    : string    : (empty)
   165 #   extra_dir           : Extra subdir for multilib             : string    : (empty)
   166 do_libc_backend_once() {
   167     local libc_mode
   168     local extra_flags
   169     local extra_dir
   170     local src_dir="${CT_SRC_DIR}/${CT_LIBC}-${CT_LIBC_VERSION}"
   171     local extra_cc_args
   172     local -a extra_config
   173     local -a extra_make_args
   174     local glibc_cflags
   175     local float_extra
   176     local endian_extra
   177 
   178     while [ $# -ne 0 ]; do
   179         eval "${1// /\\ }"
   180         shift
   181     done
   182 
   183     CT_DoLog EXTRA "Configuring C library"
   184 
   185     case "${CT_LIBC}" in
   186         eglibc)
   187             if [ "${CT_EGLIBC_CUSTOM_CONFIG}" = "y" ]; then
   188                 CT_DoExecLog ALL cp "${CT_CONFIG_DIR}/eglibc.config" option-groups.config
   189             fi
   190             if [ "${CT_EGLIBC_OPT_SIZE}" = "y" ]; then
   191                 OPTIMIZE=-Os
   192             else
   193                 OPTIMIZE=-O2
   194             fi
   195             ;;
   196         glibc)
   197             # glibc can't be built without -O2 (reference needed!)
   198             OPTIMIZE=-O2
   199             # Also, if those two are missing, iconv build breaks
   200             extra_config+=( --disable-debug --disable-sanity-checks )
   201             ;;
   202     esac
   203 
   204     # Add some default glibc config options if not given by user.
   205     # We don't need to be conditional on wether the user did set different
   206     # values, as they CT_LIBC_GLIBC_EXTRA_CONFIG_ARRAY is passed after
   207     # extra_config
   208 
   209     extra_config+=("$(do_libc_min_kernel_config)")
   210 
   211     case "${CT_THREADS}" in
   212         nptl)           extra_config+=("--with-__thread" "--with-tls");;
   213         linuxthreads)   extra_config+=("--with-__thread" "--without-tls" "--without-nptl");;
   214         none)           extra_config+=("--without-__thread" "--without-nptl")
   215                         case "${CT_LIBC_GLIBC_EXTRA_CONFIG_ARRAY[*]}" in
   216                             *-tls*) ;;
   217                             *) extra_config+=("--without-tls");;
   218                         esac
   219                         ;;
   220     esac
   221 
   222     case "${CT_SHARED_LIBS}" in
   223         y) extra_config+=("--enable-shared");;
   224         *) extra_config+=("--disable-shared");;
   225     esac
   226 
   227     float_extra="$( echo "${extra_flags}"       \
   228                     |${sed} -r -e '/^(.*[[:space:]])?-m(hard|soft)-float([[:space:]].*)?$/!d;'  \
   229                                -e 's//\2/;'     \
   230                   )"
   231     case "${float_extra}" in
   232         hard)   extra_config+=("--with-fp");;
   233         soft)   extra_config+=("--without-fp");;
   234         "")
   235             case "${CT_ARCH_FLOAT}" in
   236                 hard|softfp)    extra_config+=("--with-fp");;
   237                 soft)           extra_config+=("--without-fp");;
   238             esac
   239             ;;
   240     esac
   241 
   242     if [ "${CT_LIBC_DISABLE_VERSIONING}" = "y" ]; then
   243         extra_config+=("--disable-versioning")
   244     fi
   245 
   246     if [ "${CT_LIBC_OLDEST_ABI}" != "" ]; then
   247         extra_config+=("--enable-oldest-abi=${CT_LIBC_OLDEST_ABI}")
   248     fi
   249 
   250     case "$(do_libc_add_ons_list ,)" in
   251         "") extra_config+=("--enable-add-ons=no");;
   252         *)  extra_config+=("--enable-add-ons=$(do_libc_add_ons_list ,)");;
   253     esac
   254 
   255     if [ "${CT_LIBC_EGLIBC_HAS_PKGVERSION_BUGURL}" = "y" ]; then
   256         extra_config+=("--with-pkgversion=${CT_PKGVERSION}")
   257         [ -n "${CT_TOOLCHAIN_BUGURL}" ] && extra_config+=("--with-bugurl=${CT_TOOLCHAIN_BUGURL}")
   258     fi
   259 
   260     # Extract the endianness options if any
   261     # This should cover all possible endianness options
   262     # in gcc, but it is prone to bit-rot... :-(
   263     endian_extra="$( echo "${extra_flags}"      \
   264                      |${sed} -r -e '/^(.*[[:space:]])?-(E[BL]|m((big|little)(-endian)?|e?[bl]))([[:space:]].*)?$/!d;' \
   265                                 -e 's//\2/;'    \
   266                    )"
   267     case "${endian_extra}" in
   268         EB|mbig-endian|mbig|meb|mb)
   269             extra_cc_args="${extra_cc_args} ${endian_extra}"
   270             ;;
   271         EL|mlittle-endian|mlittle|mel|ml)
   272             extra_cc_args="${extra_cc_args} ${endian_extra}"
   273             ;;
   274         "") extra_cc_args="${extra_cc_args} ${CT_ARCH_ENDIAN_OPT}"
   275             ;;
   276     esac
   277 
   278     touch config.cache
   279     if [ "${CT_LIBC_GLIBC_FORCE_UNWIND}" = "y" ]; then
   280         echo "libc_cv_forced_unwind=yes" >>config.cache
   281         echo "libc_cv_c_cleanup=yes" >>config.cache
   282     fi
   283 
   284     # Pre-seed the configparms file with values from the config option
   285     printf "${CT_LIBC_GLIBC_CONFIGPARMS}\n" > configparms
   286 
   287     cross_cc=$(CT_Which "${CT_TARGET}-gcc")
   288     extra_cc_args+=" ${extra_flags}"
   289 
   290     CT_DoLog DEBUG "Using gcc for target    : '${cross_cc}'"
   291     CT_DoLog DEBUG "Configuring with addons : '$(do_libc_add_ons_list ,)'"
   292     CT_DoLog DEBUG "Extra config args passed: '${extra_config[*]}'"
   293     CT_DoLog DEBUG "Extra CC args passed    : '${extra_cc_args}'"
   294     CT_DoLog DEBUG "Extra flags (multilib)  : '${extra_flags}'"
   295 
   296     glibc_cflags="${CT_TARGET_CFLAGS} ${CT_LIBC_GLIBC_EXTRA_CFLAGS} ${OPTIMIZE}"
   297     case "${CT_LIBC_ENABLE_FORTIFIED_BUILD}" in
   298         y)  ;;
   299         *)  glibc_cflags+=" -U_FORTIFY_SOURCE";;
   300     esac
   301 
   302     # ./configure is mislead by our tools override wrapper for bash
   303     # so just tell it where the real bash is _on_the_target_!
   304     # Notes:
   305     # - ${ac_cv_path_BASH_SHELL} is only used to set BASH_SHELL
   306     # - ${BASH_SHELL}            is only used to set BASH
   307     # - ${BASH}                  is only used to set the shebang
   308     #                            in two scripts to run on the target
   309     # So we can safely bypass bash detection at compile time.
   310     # Should this change in a future eglibc release, we'd better
   311     # directly mangle the generated scripts _after_ they get built,
   312     # or even after they get installed... eglibc is such a sucker...
   313     echo "ac_cv_path_BASH_SHELL=/bin/bash" >>config.cache
   314 
   315     # Configure with --prefix the way we want it on the target...
   316     # There are a whole lot of settings here.  You'll probably want
   317     # to read up on what they all mean, and customize a bit, possibly by setting GLIBC_EXTRA_CONFIG_ARRAY
   318     # Compare these options with the ones used when installing the glibc headers above - they're different.
   319     # Adding "--without-gd" option to avoid error "memusagestat.c:36:16: gd.h: No such file or directory"
   320     # See also http://sources.redhat.com/ml/libc-alpha/2000-07/msg00024.html.
   321     # Set BUILD_CC, or we won't be able to build datafiles
   322     # Run explicitly through CONFIG_SHELL, or the build breaks badly (loop-of-death)
   323     # when the shell is not bash... Sigh... :-(
   324 
   325     CT_DoExecLog CFG                                                \
   326     BUILD_CC="${CT_BUILD}-gcc"                                      \
   327     CFLAGS="${glibc_cflags}"                                        \
   328     CC="${CT_TARGET}-gcc ${CT_LIBC_EXTRA_CC_ARGS} ${extra_cc_args}" \
   329     AR=${CT_TARGET}-ar                                              \
   330     RANLIB=${CT_TARGET}-ranlib                                      \
   331     "${CONFIG_SHELL}"                                               \
   332     "${src_dir}/configure"                                          \
   333         --prefix=/usr                                               \
   334         --build=${CT_BUILD}                                         \
   335         --host=${CT_TARGET}                                         \
   336         --cache-file="$(pwd)/config.cache"                          \
   337         --without-cvs                                               \
   338         --disable-profile                                           \
   339         --without-gd                                                \
   340         --with-headers="${CT_HEADERS_DIR}"                          \
   341         "${extra_config[@]}"                                        \
   342         "${CT_LIBC_GLIBC_EXTRA_CONFIG_ARRAY[@]}"
   343 
   344     # build hacks
   345     case "${CT_ARCH},${CT_ARCH_CPU}" in
   346         powerpc,8??)
   347             # http://sourceware.org/ml/crossgcc/2008-10/msg00068.html
   348             CT_DoLog DEBUG "Activating support for memset on broken ppc-8xx (CPU15 erratum)"
   349             extra_make_args+=( ASFLAGS="-DBROKEN_PPC_8xx_CPU15" )
   350             ;;
   351     esac
   352 
   353     if [ "${libc_mode}" = "startfiles" ]; then
   354         CT_DoLog EXTRA "Installing C library headers"
   355 
   356         # use the 'install-headers' makefile target to install the
   357         # headers
   358         CT_DoExecLog ALL make ${JOBSFLAGS}                          \
   359                          install_root=${CT_SYSROOT_DIR}${extra_dir} \
   360                          install-bootstrap-headers=yes              \
   361                          "${extra_make_args[@]}"                    \
   362                          install-headers
   363 
   364         # For glibc, a few headers need to be manually installed
   365         if [ "${CT_LIBC}" = "glibc" ]; then
   366             # Two headers -- stubs.h and features.h -- aren't installed by install-headers,
   367             # so do them by hand.  We can tolerate an empty stubs.h for the moment.
   368             # See e.g. http://gcc.gnu.org/ml/gcc/2002-01/msg00900.html
   369             mkdir -p "${CT_HEADERS_DIR}/gnu"
   370             CT_DoExecLog ALL touch "${CT_HEADERS_DIR}/gnu/stubs.h"
   371             CT_DoExecLog ALL cp -v "${CT_SRC_DIR}/glibc-${CT_LIBC_VERSION}/include/features.h"  \
   372                                    "${CT_HEADERS_DIR}/features.h"
   373 
   374             # Building the bootstrap gcc requires either setting inhibit_libc, or
   375             # having a copy of stdio_lim.h... see
   376             # http://sources.redhat.com/ml/libc-alpha/2003-11/msg00045.html
   377             CT_DoExecLog ALL cp -v bits/stdio_lim.h "${CT_HEADERS_DIR}/bits/stdio_lim.h"
   378 
   379             # Following error building gcc-4.0.0's gcj:
   380             #  error: bits/syscall.h: No such file or directory
   381             # solved by following copy; see http://sourceware.org/ml/crossgcc/2005-05/msg00168.html
   382             # but it breaks arm, see http://sourceware.org/ml/crossgcc/2006-01/msg00091.html
   383             case "${CT_ARCH}" in
   384                 arm)    ;;
   385                 *)  CT_DoExecLog ALL cp -v "misc/syscall-list.h"            \
   386                                            "${CT_HEADERS_DIR}/bits/syscall.h"
   387                     ;;
   388             esac
   389         fi
   390 
   391         if [ "${CT_THREADS}" = "nptl" ]; then
   392             CT_DoLog EXTRA "Installing C library start files"
   393 
   394             # there are a few object files needed to link shared libraries,
   395             # which we build and install by hand
   396             CT_DoExecLog ALL mkdir -p "${CT_SYSROOT_DIR}${extra_dir}/usr/lib"
   397             CT_DoExecLog ALL make ${JOBSFLAGS}  \
   398                         "${extra_make_args[@]}" \
   399                         csu/subdir_lib
   400             CT_DoExecLog ALL cp csu/crt1.o csu/crti.o csu/crtn.o    \
   401                                 "${CT_SYSROOT_DIR}${extra_dir}/usr/lib"
   402 
   403             # Finally, 'libgcc_s.so' requires a 'libc.so' to link against.
   404             # However, since we will never actually execute its code,
   405             # it doesn't matter what it contains.  So, treating '/dev/null'
   406             # as a C source file, we produce a dummy 'libc.so' in one step
   407             CT_DoExecLog ALL "${cross_cc}" -nostdlib        \
   408                                            -nostartfiles    \
   409                                            -shared          \
   410                                            -x c /dev/null   \
   411                                            -o "${CT_SYSROOT_DIR}${extra_dir}/usr/lib/libc.so"
   412         fi # threads == nptl
   413     else # libc_mode = final
   414         CT_DoLog EXTRA "Building C library"
   415         CT_DoExecLog ALL make ${JOBSFLAGS}              \
   416                               "${extra_make_args[@]}"   \
   417                               all
   418 
   419         CT_DoLog EXTRA "Installing C library"
   420         CT_DoExecLog ALL make ${JOBSFLAGS}                                  \
   421                               "${extra_make_args[@]}"                       \
   422                               install_root="${CT_SYSROOT_DIR}${extra_dir}"  \
   423                               install
   424 
   425         if [ "${CT_BUILD_MANUALS}" = "y" ]; then
   426             CT_DoLog EXTRA "Building and installing the C library manual"
   427             # Omit JOBSFLAGS as GLIBC has problems building the
   428             # manuals in parallel
   429             CT_DoExecLog ALL make pdf html
   430             # EGLIBC doesn't have a install-{pdf.html} and leaves the manuals
   431             # in the source directory
   432             CT_DoExecLog ALL mkdir -p ${CT_PREFIX_DIR}/share/doc
   433             CT_DoExecLog ALL cp -av ${src_dir}/manual/*.pdf ${src_dir}/manual/libc \
   434                 ${CT_PREFIX_DIR}/share/doc
   435         fi
   436 
   437         if [ "${CT_LIBC_LOCALES}" = "y" ]; then
   438             do_libc_locales
   439         fi
   440     fi
   441 }
   442 
   443 # This function finishes the C library install
   444 # This is a no-op
   445 do_libc_finish() {
   446     :
   447 }
   448 
   449 # Build up the addons list, separated with $1
   450 do_libc_add_ons_list() {
   451     local sep="$1"
   452     local addons_list="$( echo "${CT_LIBC_ADDONS_LIST}"         \
   453                           |sed -r -e "s/[[:space:],]/${sep}/g;" \
   454                         )"
   455     case "${CT_THREADS}" in
   456         none)   ;;
   457         *)      addons_list="${addons_list}${sep}${CT_THREADS}";;
   458     esac
   459     [ "${CT_LIBC_GLIBC_USE_PORTS}" = "y" ] && addons_list="${addons_list}${sep}ports"
   460     # Remove duplicate, leading and trailing separators
   461     echo "${addons_list}" |sed -r -e "s/${sep}+/${sep}/g; s/^${sep}//; s/${sep}\$//;"
   462 }
   463 
   464 # Compute up the minimum supported Linux kernel version
   465 do_libc_min_kernel_config() {
   466     local min_kernel_config
   467 
   468     case "${CT_LIBC_GLIBC_EXTRA_CONFIG_ARRAY[*]}" in
   469         *--enable-kernel*) ;;
   470         *)  if [ "${CT_LIBC_GLIBC_KERNEL_VERSION_AS_HEADERS}" = "y" ]; then
   471                 # We can't rely on the kernel version from the configuration,
   472                 # because it might not be available if the user uses pre-installed
   473                 # headers. On the other hand, both method will have the kernel
   474                 # version installed in "usr/include/linux/version.h" in the sysroot.
   475                 # Parse that instead of having two code-paths.
   476                 version_code_file="${CT_SYSROOT_DIR}/usr/include/linux/version.h"
   477                 if [ ! -f "${version_code_file}" -o ! -r "${version_code_file}" ]; then
   478                     CT_Abort "Linux version is unavailable in installed headers files"
   479                 fi
   480                 version_code="$( grep -E LINUX_VERSION_CODE "${version_code_file}"  \
   481                                  |cut -d ' ' -f 3                                   \
   482                                )"
   483                 version=$(((version_code>>16)&0xFF))
   484                 patchlevel=$(((version_code>>8)&0xFF))
   485                 sublevel=$((version_code&0xFF))
   486                 min_kernel_config="${version}.${patchlevel}.${sublevel}"
   487             elif [ "${CT_LIBC_GLIBC_KERNEL_VERSION_CHOSEN}" = "y" ]; then
   488                 # Trim the fourth part of the linux version, keeping only the first three numbers
   489                 min_kernel_config="$( echo "${CT_LIBC_GLIBC_MIN_KERNEL_VERSION}"            \
   490                                       |sed -r -e 's/^([^.]+\.[^.]+\.[^.]+)(|\.[^.]+)$/\1/;' \
   491                                     )"
   492             fi
   493             echo "--enable-kernel=${min_kernel_config}"
   494             ;;
   495     esac
   496 }