#! /bin/sh
#
# generate shlibs/symbols files for samba packages
#
# samba ships a mix of:
#   public libraries with stable ABI in /usr/lib
#   public libraries in /usr/lib
#   public python libraries in /usr/lib
#   private libraries in /usr/lib/samba/
#   plugins in /usr/lib/samba/*/
#
# For public libraries with stable ABI we generate symbols files.
# These are listed in d/package.symbols files.
# For other librries, we only need to generate shlibs files
# with basic version information so that dpkg-shlibdeps will find them.
# Here, for libs without .symbols file, we have 2 choices:
# for public libraries we generate ($pkg >> $version) dependency in
# shlibs file, but for private libs the relation is equality (=).
# We do not process plugins, and we do not process python objects.
#
# dh_makeshlibs is too difficult to use here, we have much simpler approach.
# We know exactly where our libs resides (dh_makeshlibs looks everywhere)
# and we know filename patterns to recognize our shared libs.
# dh_makeshlibs can not be used to generate symbols files for *some* libraries
# (it is either all if .symbols is provided, or nothing if not).
# It is easier to take strightforward approach than to fight a tool.

set -e
umask 022

: ${DEB_VERSION:=$(dpkg-parsechangelog -S Version)}
: ${DEB_HOST_MULTIARCH:=$(dpkg-architecture -qDEB_HOST_MULTIARCH)}

# arguments in form pkg1=custom-version pkg2=version2...
# to override ${DEB_VERSION} for the given packages
custvers="$*"

lib=usr/lib/${DEB_HOST_MULTIARCH}  # the only library directory
smblib=$lib/samba                  # samba private libraries

rc=0

# process all packages but skip those without libs of interst
for pkg in $(dh_listpackages); do
  pd=debian/$pkg # package directory

  # find library directories
  libs=
  for x in $lib $smblib ; do
    [ -d $pd/$x ] && libs="$libs $x"
  done
  [ -n "$libs" ] || continue
  # find libraries in library dirs (search for libfoo.so.NN names)
  libs="$(cd $pd; find $libs -maxdepth 1 -regex '.*\.so.[0-9]+')"
  [ -n "$libs" ] || continue

  ver=${DEB_VERSION}
  for x in $custvers; do
    case "$x" in
      ( $pkg=* ) ver=${x#*=}; break;;
    esac
  done
  echo "${0##*/}: processing $pkg $ver"

  if [ libsmbclient0 = $pkg ]; then
     # run dh_makeshlibs to emit t64:Provides properly
     # it should contain just one (public) library file
     dh_makeshlibs -p $pkg -- -v$ver || rc=1
     continue
  fi

  # generate shlibs file: for public libs use >>$ver, for private =$ver
  mkdir -p $pd/DEBIAN
  for x in $libs; do
    case "$x" in
      ($smblib/*) rel="= $ver";;
      (*)         rel=">> $ver~";;
    esac
    x=${x##*/}
    echo "${x%.so.*} ${x#**.so.} $pkg ($rel)"
  done | LC_ALL=C sort > $pd/DEBIAN/shlibs

  # see if we have any public (eg, not in /usr/lib/samba/) libs
  if echo "$libs" | fgrep -qv $smblib/; then
    # generate ldconfig trigger activation
    x=debian/.debhelper/generated/$pkg/triggers
    y="activate-noawait ldconfig"
    mkdir -p ${x%/*}
    if [ ! -f $x ] || ! grep -q "^$y" $x; then
      echo "# Triggers added by Samba:$0 ${DEB_VERSION}
$y" >> $x
    fi
  fi

  # packages without .symbols file need no further processing
  [ -f debian/$pkg.symbols ] || continue

  # process libraries listed in .symbols files with dpkg-gensymbols
  # find libraries listed in .symbols, find full path of them in $libs
  # and construct -e$filename argument list in $checklibs for dpkg-gensymbols
  symlibs=$(sed -n -r 's/^([a-z][^ ]*) .*/\1/p' debian/$pkg.symbols)
  checklibs=
  for x in $symlibs; do
    for y in $libs; do
      case $y in (*/$x) checklibs="$checklibs -e$pd/$y"; break;; esac
    done
  done
  # dpkg-gensymbols will detect listed but missing libs
  # here we continue if dpkg-gensymbols failed to collect all errors
  x=0; dpkg-gensymbols -c4 -p$pkg -P$pd -v$ver -l$smblib $checklibs || x=$?
  if [ $x = 0 ]; then :
  elif [ $x = 2 ]; then rc=1
  else exit 1
  fi

done

exit $rc