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