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 # @SUPPORTED_EAPIS: 4 5 6 7
   8 # @BLURB: Defines the gen_usr_ldscript function.
   9
  10 if [[ -z ${_USR_LDSCRIPT_ECLASS} ]]; then
  11 _USR_LDSCRIPT_ECLASS=1
  12
  13 case ${EAPI:-0} in
  14         4|5|6|7) ;;
  15         *) die "EAPI=${EAPI} is not supported" ;;
  16 esac
  17
  18 inherit multilib toolchain-funcs
  19
  20 IUSE="split-usr"
  21
  22 # @FUNCTION: gen_usr_ldscript
  23 # @USAGE: [-a] <list of libs to create linker scripts for>
  24 # @DESCRIPTION:
  25 # This function generate linker scripts in /usr/lib for dynamic
  26 # libs in /lib.  This is to fix linking problems when you have
  27 # the .so in /lib, and the .a in /usr/lib.  What happens is that
  28 # in some cases when linking dynamic, the .a in /usr/lib is used
  29 # instead of the .so in /lib due to gcc/libtool tweaking ld's
  30 # library search path.  This causes many builds to fail.
  31 # See bug #4411 for more info.
  32 #
  33 # Note that you should in general use the unversioned name of
  34 # the library (libfoo.so), as ldconfig should usually update it
  35 # correctly to point to the latest version of the library present.
  36 gen_usr_ldscript() {
  37         local lib libdir=$(get_libdir) output_format="" auto=false suffix=$(get_libname)
  38
  39         tc-is-static-only && return
  40
  41         # We only care about stuffing / for the native ABI. #479448
  42         if [[ $(type -t multilib_is_native_abi) == "function" ]] ; then
  43                 multilib_is_native_abi || return 0
  44         fi
  45
  46         # Eventually we'd like to get rid of this func completely #417451
  47         case ${CTARGET:-${CHOST}} in
  48         *-darwin*) ;;
  49         *-android*) return 0 ;;
  50         *linux*|*-freebsd*|*-openbsd*|*-netbsd*)
  51                 use prefix && return 0
  52                 use split-usr || return 0
  53                 ;;
  54         *) return 0 ;;
  55         esac
  56
  57         # Just make sure it exists
  58         dodir /usr/${libdir}
  59
  60         if [[ $1 == "-a" ]] ; then
  61                 auto=true
  62                 shift
  63                 dodir /${libdir}
  64         fi
  65
  66         # OUTPUT_FORMAT gives hints to the linker as to what binary format
  67         # is referenced ... makes multilib saner
  68         local flags=( ${CFLAGS} ${LDFLAGS} -Wl,--verbose )
  69         if $(tc-getLD) --version | grep -q 'GNU gold' ; then
  70                 # If they're using gold, manually invoke the old bfd. #487696
  71                 local d="${T}/bfd-linker"
  72                 mkdir -p "${d}"
  73                 ln -sf $(which ${CHOST}-ld.bfd) "${d}"/ld
  74                 flags+=( -B"${d}" )
  75         fi
  76         output_format=$($(tc-getCC) "${flags[@]}" 2>&1 | sed -n 's/^OUTPUT_FORMAT("\([^"]*\)",.*/\1/p')
  77         [[ -n ${output_format} ]] && output_format="OUTPUT_FORMAT ( ${output_format} )"
  78
  79         for lib in "$@" ; do
  80                 local tlib
  81                 if ${auto} ; then
  82                         lib="lib${lib}${suffix}"
  83                 else
  84                         # Ensure /lib/${lib} exists to avoid dangling scripts/symlinks.
  85                         # This especially is for AIX where $(get_libname) can return ".a",
  86                         # so /lib/${lib} might be moved to /usr/lib/${lib} (by accident).
  87                         [[ -r ${ED%/}/${libdir}/${lib} ]] || continue
  88                         #TODO: better die here?
  89                 fi
  90
  91                 case ${CTARGET:-${CHOST}} in
  92                 *-darwin*)
  93                         if ${auto} ; then
  94                                 tlib=$(scanmacho -qF'%S#F' "${ED%/}"/usr/${libdir}/${lib})
  95                         else
  96                                 tlib=$(scanmacho -qF'%S#F' "${ED%/}"/${libdir}/${lib})
  97                         fi
  98                         [[ -z ${tlib} ]] && die "unable to read install_name from ${lib}"
  99                         tlib=${tlib##*/}
 100
 101                         if ${auto} ; then
 102                                 mv "${ED%/}"/usr/${libdir}/${lib%${suffix}}.*${suffix#.} "${ED%/}"/${libdir}/ || die
 103                                 # some install_names are funky: they encode a version
 104                                 if [[ ${tlib} != ${lib%${suffix}}.*${suffix#.} ]] ; then
 105                                         mv "${ED%/}"/usr/${libdir}/${tlib%${suffix}}.*${suffix#.} "${ED%/}"/${libdir}/ || die
 106                                 fi
 107                                 rm -f "${ED%/}"/${libdir}/${lib}
 108                         fi
 109
 110                         # Mach-O files have an id, which is like a soname, it tells how
 111                         # another object linking against this lib should reference it.
 112                         # Since we moved the lib from usr/lib into lib this reference is
 113                         # wrong.  Hence, we update it here.  We don't configure with
 114                         # libdir=/lib because that messes up libtool files.
 115                         # Make sure we don't lose the specific version, so just modify the
 116                         # existing install_name
 117                         if [[ ! -w "${ED%/}/${libdir}/${tlib}" ]] ; then
 118                                 chmod u+w "${ED%/}/${libdir}/${tlib}" # needed to write to it
 119                                 local nowrite=yes
 120                         fi
 121                         install_name_tool \
 122                                 -id "${EPREFIX}"/${libdir}/${tlib} \
 123                                 "${ED%/}"/${libdir}/${tlib} || die "install_name_tool failed"
 124                         [[ -n ${nowrite} ]] && chmod u-w "${ED%/}/${libdir}/${tlib}"
 125                         # Now as we don't use GNU binutils and our linker doesn't
 126                         # understand linker scripts, just create a symlink.
 127                         pushd "${ED%/}/usr/${libdir}" > /dev/null
 128                         ln -snf "../../${libdir}/${tlib}" "${lib}"
 129                         popd > /dev/null
 130                         ;;
 131                 *)
 132                         if ${auto} ; then
 133                                 tlib=$(scanelf -qF'%S#F' "${ED%/}"/usr/${libdir}/${lib})
 134                                 [[ -z ${tlib} ]] && die "unable to read SONAME from ${lib}"
 135                                 mv "${ED%/}"/usr/${libdir}/${lib}* "${ED%/}"/${libdir}/ || die
 136                                 # some SONAMEs are funky: they encode a version before the .so
 137                                 if [[ ${tlib} != ${lib}* ]] ; then
 138                                         mv "${ED%/}"/usr/${libdir}/${tlib}* "${ED%/}"/${libdir}/ || die
 139                                 fi
 140                                 rm -f "${ED%/}"/${libdir}/${lib}
 141                         else
 142                                 tlib=${lib}
 143                         fi
 144                         cat > "${ED%/}/usr/${libdir}/${lib}" <<-END_LDSCRIPT
 145                         /* GNU ld script
 146                            Since Gentoo has critical dynamic libraries in /lib, and the static versions
 147                            in /usr/lib, we need to have a "fake" dynamic lib in /usr/lib, otherwise we
 148                            run into linking problems.  This "fake" dynamic lib is a linker script that
 149                            redirects the linker to the real lib.  And yes, this works in the cross-
 150                            compiling scenario as the sysroot-ed linker will prepend the real path.
 151
 152                            See bug https://bugs.gentoo.org/4411 for more info.
 153                          */
 154                         ${output_format}
 155                         GROUP ( ${EPREFIX}/${libdir}/${tlib} )
 156                         END_LDSCRIPT
 157                         ;;
 158                 esac
 159                 fperms a+x "/usr/${libdir}/${lib}" || die "could not change perms on ${lib}"
 160         done
 161 }
 162
 163 fi # _USR_LDSCRIPT_ECLASS