eclass/usr-ldscript.eclass

   1 # Copyright 2019 Gentoo Authors
   2 # Distributed under the terms of the GNU General Public License v2
   3
   4 # @ECLASS: usr-ldscript.eclass
   5 # @MAINTAINER:
   6 # Toolchain Ninjas <toolchain@gentoo.org>
   7 # @BLURB: Defines the gen_usr_ldscript function.
   8
   9 if [[ -z ${_USR_LDSCRIPT_ECLASS} ]]; then
  10 _USR_LDSCRIPT_ECLASS=1
  11
  12 inherit multilib toolchain-funcs
  13
  14 IUSE="split-usr"
  15
  16 # @FUNCTION: gen_usr_ldscript
  17 # @USAGE: [-a] <list of libs to create linker scripts for>
  18 # @DESCRIPTION:
  19 # This function generate linker scripts in /usr/lib for dynamic
  20 # libs in /lib.  This is to fix linking problems when you have
  21 # the .so in /lib, and the .a in /usr/lib.  What happens is that
  22 # in some cases when linking dynamic, the .a in /usr/lib is used
  23 # instead of the .so in /lib due to gcc/libtool tweaking ld's
  24 # library search path.  This causes many builds to fail.
  25 # See bug #4411 for more info.
  26 #
  27 # Note that you should in general use the unversioned name of
  28 # the library (libfoo.so), as ldconfig should usually update it
  29 # correctly to point to the latest version of the library present.
  30 gen_usr_ldscript() {
  31         local lib libdir=$(get_libdir) output_format="" auto=false suffix=$(get_libname)
  32         [[ -z ${ED+set} ]] && local ED=${D%/}${EPREFIX}/
  33
  34         tc-is-static-only && return
  35
  36         # We only care about stuffing / for the native ABI. #479448
  37         if [[ $(type -t multilib_is_native_abi) == "function" ]] ; then
  38                 multilib_is_native_abi || return 0
  39         fi
  40
  41         # Eventually we'd like to get rid of this func completely #417451
  42         case ${CTARGET:-${CHOST}} in
  43         *-darwin*) ;;
  44         *-android*) return 0 ;;
  45         *linux*|*-freebsd*|*-openbsd*|*-netbsd*)
  46                 use prefix && return 0
  47                 use split-usr || return 0
  48                 ;;
  49         *) return 0 ;;
  50         esac
  51
  52         # Just make sure it exists
  53         dodir /usr/${libdir}
  54
  55         if [[ $1 == "-a" ]] ; then
  56                 auto=true
  57                 shift
  58                 dodir /${libdir}
  59         fi
  60
  61         # OUTPUT_FORMAT gives hints to the linker as to what binary format
  62         # is referenced ... makes multilib saner
  63         local flags=( ${CFLAGS} ${LDFLAGS} -Wl,--verbose )
  64         if $(tc-getLD) --version | grep -q 'GNU gold' ; then
  65                 # If they're using gold, manually invoke the old bfd. #487696
  66                 local d="${T}/bfd-linker"
  67                 mkdir -p "${d}"
  68                 ln -sf $(which ${CHOST}-ld.bfd) "${d}"/ld
  69                 flags+=( -B"${d}" )
  70         fi
  71         output_format=$($(tc-getCC) "${flags[@]}" 2>&1 | sed -n 's/^OUTPUT_FORMAT("\([^"]*\)",.*/\1/p')
  72         [[ -n ${output_format} ]] && output_format="OUTPUT_FORMAT ( ${output_format} )"
  73
  74         for lib in "$@" ; do
  75                 local tlib
  76                 if ${auto} ; then
  77                         lib="lib${lib}${suffix}"
  78                 else
  79                         # Ensure /lib/${lib} exists to avoid dangling scripts/symlinks.
  80                         # This especially is for AIX where $(get_libname) can return ".a",
  81                         # so /lib/${lib} might be moved to /usr/lib/${lib} (by accident).
  82                         [[ -r ${ED}/${libdir}/${lib} ]] || continue
  83                         #TODO: better die here?
  84                 fi
  85
  86                 case ${CTARGET:-${CHOST}} in
  87                 *-darwin*)
  88                         if ${auto} ; then
  89                                 tlib=$(scanmacho -qF'%S#F' "${ED}"/usr/${libdir}/${lib})
  90                         else
  91                                 tlib=$(scanmacho -qF'%S#F' "${ED}"/${libdir}/${lib})
  92                         fi
  93                         [[ -z ${tlib} ]] && die "unable to read install_name from ${lib}"
  94                         tlib=${tlib##*/}
  95
  96                         if ${auto} ; then
  97                                 mv "${ED}"/usr/${libdir}/${lib%${suffix}}.*${suffix#.} "${ED}"/${libdir}/ || die
  98                                 # some install_names are funky: they encode a version
  99                                 if [[ ${tlib} != ${lib%${suffix}}.*${suffix#.} ]] ; then
 100                                         mv "${ED}"/usr/${libdir}/${tlib%${suffix}}.*${suffix#.} "${ED}"/${libdir}/ || die
 101                                 fi
 102                                 rm -f "${ED}"/${libdir}/${lib}
 103                         fi
 104
 105                         # Mach-O files have an id, which is like a soname, it tells how
 106                         # another object linking against this lib should reference it.
 107                         # Since we moved the lib from usr/lib into lib this reference is
 108                         # wrong.  Hence, we update it here.  We don't configure with
 109                         # libdir=/lib because that messes up libtool files.
 110                         # Make sure we don't lose the specific version, so just modify the
 111                         # existing install_name
 112                         if [[ ! -w "${ED}/${libdir}/${tlib}" ]] ; then
 113                                 chmod u+w "${ED}${libdir}/${tlib}" # needed to write to it
 114                                 local nowrite=yes
 115                         fi
 116                         install_name_tool \
 117                                 -id "${EPREFIX}"/${libdir}/${tlib} \
 118                                 "${ED}"/${libdir}/${tlib} || die "install_name_tool failed"
 119                         [[ -n ${nowrite} ]] && chmod u-w "${ED}${libdir}/${tlib}"
 120                         # Now as we don't use GNU binutils and our linker doesn't
 121                         # understand linker scripts, just create a symlink.
 122                         pushd "${ED}/usr/${libdir}" > /dev/null
 123                         ln -snf "../../${libdir}/${tlib}" "${lib}"
 124                         popd > /dev/null
 125                         ;;
 126                 *)
 127                         if ${auto} ; then
 128                                 tlib=$(scanelf -qF'%S#F' "${ED}"/usr/${libdir}/${lib})
 129                                 [[ -z ${tlib} ]] && die "unable to read SONAME from ${lib}"
 130                                 mv "${ED}"/usr/${libdir}/${lib}* "${ED}"/${libdir}/ || die
 131                                 # some SONAMEs are funky: they encode a version before the .so
 132                                 if [[ ${tlib} != ${lib}* ]] ; then
 133                                         mv "${ED}"/usr/${libdir}/${tlib}* "${ED}"/${libdir}/ || die
 134                                 fi
 135                                 rm -f "${ED}"/${libdir}/${lib}
 136                         else
 137                                 tlib=${lib}
 138                         fi
 139                         cat > "${ED}/usr/${libdir}/${lib}" <<-END_LDSCRIPT
 140                         /* GNU ld script
 141                            Since Gentoo has critical dynamic libraries in /lib, and the static versions
 142                            in /usr/lib, we need to have a "fake" dynamic lib in /usr/lib, otherwise we
 143                            run into linking problems.  This "fake" dynamic lib is a linker script that
 144                            redirects the linker to the real lib.  And yes, this works in the cross-
 145                            compiling scenario as the sysroot-ed linker will prepend the real path.
 146
 147                            See bug https://bugs.gentoo.org/4411 for more info.
 148                          */
 149                         ${output_format}
 150                         GROUP ( ${EPREFIX}/${libdir}/${tlib} )
 151                         END_LDSCRIPT
 152                         ;;
 153                 esac
 154                 fperms a+x "/usr/${libdir}/${lib}" || die "could not change perms on ${lib}"
 155         done
 156 }
 157
 158 fi # _USR_LDSCRIPT_ECLASS