eclass/ltprune.eclass

   1 # Copyright 1999-2017 Gentoo Foundation
   2 # Distributed under the terms of the GNU General Public License v2
   3
   4 # @ECLASS: ltprune.eclass
   5 # @MAINTAINER:
   6 # Michał Górny <mgorny@gentoo.org>
   7 # @BLURB: Smart .la file pruning
   8 # @DESCRIPTION:
   9 # A function to locate and remove unnecessary .la files.
  10 #
  11 # Discouraged. Whenever possible, please use much simpler:
  12 # @CODE
  13 # find "${D}" -name '*.la' -delete || die
  14 # @CODE
  15
  16 if [[ -z ${_LTPRUNE_ECLASS} ]]; then
  17
  18 case ${EAPI:-0} in
  19         0|1|2|3|4|5|6)
  20                 ;;
  21         *)
  22                 die "${ECLASS}: banned in EAPI=${EAPI}; use 'find' instead";;
  23 esac
  24
  25 inherit toolchain-funcs
  26
  27 # @FUNCTION: prune_libtool_files
  28 # @USAGE: [--all|--modules]
  29 # @DESCRIPTION:
  30 # Locate unnecessary libtool files (.la) and libtool static archives
  31 # (.a) and remove them from installation image.
  32 #
  33 # By default, .la files are removed whenever the static linkage can
  34 # either be performed using pkg-config or doesn't introduce additional
  35 # flags.
  36 #
  37 # If '--modules' argument is passed, .la files for modules (plugins) are
  38 # removed as well. This is usually useful when the package installs
  39 # plugins and the plugin loader does not use .la files.
  40 #
  41 # If '--all' argument is passed, all .la files are removed without
  42 # performing any heuristic on them. You shouldn't ever use that,
  43 # and instead report a bug in the algorithm instead.
  44 #
  45 # The .a files are only removed whenever corresponding .la files state
  46 # that they should not be linked to, i.e. whenever these files
  47 # correspond to plugins.
  48 #
  49 # Note: if your package installs both static libraries and .pc files
  50 # which use variable substitution for -l flags, you need to add
  51 # pkg-config to your DEPEND.
  52 prune_libtool_files() {
  53         debug-print-function ${FUNCNAME} "$@"
  54
  55         local removing_all removing_modules opt
  56         for opt; do
  57                 case "${opt}" in
  58                         --all)
  59                                 removing_all=1
  60                                 removing_modules=1
  61                                 ;;
  62                         --modules)
  63                                 removing_modules=1
  64                                 ;;
  65                         *)
  66                                 die "Invalid argument to ${FUNCNAME}(): ${opt}"
  67                 esac
  68         done
  69
  70         local f
  71         local queue=()
  72         while IFS= read -r -d '' f; do # for all .la files
  73                 local archivefile=${f/%.la/.a}
  74
  75                 # The following check is done by libtool itself.
  76                 # It helps us avoid removing random files which match '*.la',
  77                 # see bug #468380.
  78                 if ! sed -n -e '/^# Generated by .*libtool/q0;4q1' "${f}"; then
  79                         continue
  80                 fi
  81
  82                 [[ ${f} != ${archivefile} ]] || die 'regex sanity check failed'
  83                 local reason= pkgconfig_scanned=
  84                 local snotlink=$(sed -n -e 's:^shouldnotlink=::p' "${f}")
  85
  86                 if [[ ${snotlink} == yes ]]; then
  87
  88                         # Remove static libs we're not supposed to link against.
  89                         if [[ -f ${archivefile} ]]; then
  90                                 einfo "Removing unnecessary ${archivefile#${D%/}} (static plugin)"
  91                                 queue+=( "${archivefile}" )
  92                         fi
  93
  94                         # The .la file may be used by a module loader, so avoid removing it
  95                         # unless explicitly requested.
  96                         if [[ ${removing_modules} ]]; then
  97                                 reason='module'
  98                         fi
  99
 100                 else
 101
 102                         # Remove .la files when:
 103                         # - user explicitly wants us to remove all .la files,
 104                         # - respective static archive doesn't exist,
 105                         # - they are covered by a .pc file already,
 106                         # - they don't provide any new information (no libs & no flags).
 107
 108                         if [[ ${removing_all} ]]; then
 109                                 reason='requested'
 110                         elif [[ ! -f ${archivefile} ]]; then
 111                                 reason='no static archive'
 112                         elif [[ ! $(sed -nre \
 113                                         "s/^(dependency_libs|inherited_linker_flags)='(.*)'$/\2/p" \
 114                                         "${f}") ]]; then
 115                                 reason='no libs & flags'
 116                         else
 117                                 if [[ ! ${pkgconfig_scanned} ]]; then
 118                                         # Create a list of all .pc-covered libs.
 119                                         local pc_libs=()
 120                                         if [[ ! ${removing_all} ]]; then
 121                                                 local pc
 122                                                 local tf=${T}/prune-lt-files.pc
 123                                                 local pkgconf=$(tc-getPKG_CONFIG)
 124
 125                                                 while IFS= read -r -d '' pc; do # for all .pc files
 126                                                         local arg libs
 127
 128                                                         # Use pkg-config if available (and works),
 129                                                         # fallback to sed.
 130                                                         if ${pkgconf} --exists "${pc}" &>/dev/null; then
 131                                                                 sed -e '/^Requires:/d' "${pc}" > "${tf}"
 132                                                                 libs=$(${pkgconf} --libs "${tf}")
 133                                                         else
 134                                                                 libs=$(sed -ne 's/^Libs://p' "${pc}")
 135                                                         fi
 136
 137                                                         for arg in ${libs}; do
 138                                                                 if [[ ${arg} == -l* ]]; then
 139                                                                         if [[ ${arg} == '*$*' ]]; then
 140                                                                                 eerror "${FUNCNAME}: variable substitution likely failed in ${pc}"
 141                                                                                 eerror "(arg: ${arg})"
 142                                                                                 eerror "Most likely, you need to add virtual/pkgconfig to DEPEND."
 143                                                                                 die "${FUNCNAME}: unsubstituted variable found in .pc"
 144                                                                         fi
 145
 146                                                                         pc_libs+=( lib${arg#-l}.la )
 147                                                                 fi
 148                                                         done
 149                                                 done < <(find "${D}" -type f -name '*.pc' -print0)
 150
 151                                                 rm -f "${tf}"
 152                                         fi
 153
 154                                         pkgconfig_scanned=1
 155                                 fi # pkgconfig_scanned
 156
 157                                 has "${f##*/}" "${pc_libs[@]}" && reason='covered by .pc'
 158                         fi # removal due to .pc
 159
 160                 fi # shouldnotlink==no
 161
 162                 if [[ ${reason} ]]; then
 163                         einfo "Removing unnecessary ${f#${D%/}} (${reason})"
 164                         queue+=( "${f}" )
 165                 fi
 166         done < <(find "${D}" -xtype f -name '*.la' -print0)
 167
 168         if [[ ${queue[@]} ]]; then
 169                 rm -f "${queue[@]}"
 170         fi
 171 }
 172
 173 _LTPRUNE_ECLASS=1
 174 fi #_LTPRUNE_ECLASS