#!/bin/sh -efu
#
# Copyright (C) 2000-2006  Dmitry V. Levin <ldv@altlinux.org>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#

. @RPMCONFIGDIR@/functions

dump_ld_config='@RPMCONFIGDIR@/dump_ld_config'

[ -n "${RPM_LIBDIR-}" ] || RPM_LIBDIR=`rpm --eval %_libdir`
[ -n "${RPM_LIB-}" ] || RPM_LIB=`rpm --eval %_lib`

DEF_RPM_FINDPROV_LIB_PATH="/$RPM_LIB $RPM_LIBDIR $("$dump_ld_config")"
[ -z "${RPM_BUILD_ROOT-}" ] ||
DEF_RPM_FINDPROV_LIB_PATH="$("$dump_ld_config" '' "$RPM_BUILD_ROOT") $DEF_RPM_FINDPROV_LIB_PATH"
DEF_RPM_FINDPROV_LIB_PATH="$(IFS="$IFS:"; echo '' $DEF_RPM_FINDPROV_LIB_PATH '')"
Debug "DEF_RPM_FINDPROV_LIB_PATH=$DEF_RPM_FINDPROV_LIB_PATH"

RPM_FINDPROV_LIB_PATH="$(IFS="$IFS:"; echo '' ${RPM_FINDPROV_LIB_PATH-} $DEF_RPM_FINDPROV_LIB_PATH '')"
Debug "RPM_FINDPROV_LIB_PATH=$RPM_FINDPROV_LIB_PATH"

LibProv()
{
	local f="$1" fname dir basename
	fname=${f#${RPM_BUILD_ROOT-}}
	dir=${fname%/*}
	basename=${fname##*/}

	# Check library location.
	[ -n "$dir" ] && [ -n "$basename" ] || return 0
	[ "$dir" = "/$RPM_LIB/security" ] || [ -z "${RPM_FINDPROV_LIB_PATH##* $dir *}" ] || return 0

	# Obtain objdump info.
	local dump
	if ! dump=$(objdump -p "$f"); then
		Warning "$f: objdump failed"
		return 0
	fi

	# Special case for PAM plugins.
	if [ "$dir" = "/$RPM_LIB/security" ]; then
		printf 'PAM(%s)\n' "$basename"
		return 0
	fi

	local soname suffix braces
	soname=$(printf %s\\n "$dump" |sed -ne 's/^[[:space:]]*SONAME[[:space:]]\+\([^[:space:]]\+\)[[:space:]]*$/\1/p')
	suffix=$(printf %s\\n "$dump" |sed -ne 's/^.*file format \(elf64\).*$/(64bit)/p')
	[ -z "$suffix" ] && braces= || braces='()'

	# For libraries with soname, ignore all but files named as soname.
	[ -z "$soname" ] || [ "$soname" = "$basename" ] || return 0

	# Treat symlinks specially.
	if [ -L "$f" ]; then
		[ -n "$soname" ] || return 0
		# Ignore symlinks leading out of buildroot.
		local realpath
		realpath=$(readlink -fv "$f")
		[ -z "${realpath##${RPM_BUILD_ROOT-}/*}" ] || return 0
		# Ignore symlinks to shorter locations.
		local realdir
		realdir=${realpath##${RPM_BUILD_ROOT-}}
		realdir=${realdir%/*}
		[ "${#dir}" -le "${#realdir}" ] || return 0
	fi

	# soname is either empty or equal to basename, so...
	soname=$basename

	# Check for non-default path.
	local provdir=
	[ -z "${DEF_RPM_FINDPROV_LIB_PATH##* $dir *}" ] || provdir=$dir/

	# Output version definitions.
	printf %s\\n "$dump" |
	sed -n '/^Version definitions:$/,/^$/{/^[0-9]/p}' |
	awk -v provdir="$provdir" -v soname="$soname" -v suffix="$suffix" \
		'NF==4 && $4!=soname {printf "%s%s(%s)%s\n", provdir, soname, $4, suffix}'

	# Do main provides entry.
	local provname="$provdir$soname$braces$suffix"
	ENABLE_SET_VERSIONS=1
	if [ -z "$ENABLE_SET_VERSIONS" ]; then
		printf '%s\n' "$provname"
		return 0
	fi
	local sym="$(ProvidedSymbols "$f")"
	if [ -n "$sym" ]; then
		local n bpp set
		n=$(printf '%s\n' "$sym" |wc -l)
		Verbose "$f: $n symbols"
		bpp=$(SuggestBPP "$n")
		set=$(printf '%s\n' "$sym" |@RPMCONFIGDIR@/mkset "$bpp")
		printf '%s = %s\n' "$provname" "$set"
	else
		Warning "$f: no symbols"
		printf '%s\n' "$provname"
	fi
}

ProvidedSymbols()
{
	readelf --wide --dyn-syms "$1" |
	awk '+$1 && NF>=8 &&
		# dl-lookup.c: /st_value
		($2!="00000000" && $2!="0000000000000000" || $4=="TLS") &&
		# dl-lookup.c: /st_shndx
		($7!="UND") &&
		# dl-lookup.c: /ALLOWED_STT
		($4=="NOTYPE" || $4=="OBJECT" || $4 == "FUNC" || $4=="COMMON" || $4=="TLS" || $4=="IFUNC") &&
		# dl-lookup.c: /hidden
		($6=="DEFAULT" || $6=="PROTECTED") &&
		# dl-lookup.c: /switch.*ST_BIND
		($5=="GLOBAL" || $5=="WEAK" || $5 == "UNIQUE") &&
		# Ignore special symbols found in each library:
		($8!="__bss_start" && $8!="_edata" && $8!="_end" && $8!="_fini" && $8!="_init") {
			sym = $8
			# No symbol versioning yet.
			ix = index(sym, "@")
			if (ix > 1)
				sym = substr(sym, 0, ix-1)
			print sym
		}' |
	LC_ALL=C sort -u
}

SuggestBPP()
{
	# For the number of symbols in the range 2^{m-1}..2^m-1,
	# use m+10 bits per symbol.  Upper bound on the error rate
	# is 2^{-10} (about 0.1%).
	perl -le 'print int log(shift) / log(2) + 11' "$1"
}

ArgvFileAction LibProv "$@"