#!/bin/sh
# Copyright 1999-2007 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2

appname=${0##*/}

# If baselayout is broken, define our own functions
[ -r /etc/init.d/functions.sh ] && . /etc/init.d/functions.sh
if ! type eend >/dev/null 2>&1 || ! eend 0 >/dev/null 2>&1; then
	einfo() { echo " * $*"; }
	eerror() { echo " * $*" >&2; return 1; }
	eindent() { :; }
	eoutdent() { :; }
fi

# No temporary files used, so nothing to clean up :)
trap "export RC_EINDENT=; echo; eerror 'Caught interrupt'; exit 1" \
	SIGINT SIGQUIT

print_usage() {
	cat << EOF
Usage: ${appname} [OPTIONS] [--] [EMERGE_OPTIONS]

Broken reverse dependency rebuilder.

  -h, --help           Print this usage
  -e, --exact          Emerge based on exact package version
  -C, --nocolor        Turn off colored output
  -L, --library NAME   Emerge existing packages that use the library with NAME
      --library=NAME   NAME can be a full path to the library or a basic
                       regular expression (man grep)

Calls emerge, all other options are used for it (e. g. -p, --pretend).

Report bugs to <http://bugs.gentoo.org>
EOF
}

# Have we linked to this library?
elf_linked() {
	local f=$1
	shift
	while [ -n "$1" ]; do
		ldd "${f}" 2>/dev/null | grep -q "=> $1 " && return 0
		shift
	done
	return 1
}

# Work out of we really need this library or not
elf_needed() {
	local f=$1
	shift
	while [ -n "$1" ]; do
		objdump -p "${f}" 2>/dev/null | \
			grep -vF "${ld_mask:=$'\a'}" | \
			grep -q "^  NEEDED      ${1##*/}" && return 0
		shift
	done
	return 1
}

elf_broken() {
	local lib=
	
	for lib in $(ldd "$1" 2>/dev/null | \
		sed -n -e 's/[[:space:]]*\(.*\) => not found.*/\1/p'); do
		if elf_needed "$1" "${lib}"; then
			echo "(missing ${lib})"
			return 0
		fi
	done
	return 1
}

# Check that all direct files exist in .la files
la_broken() {
	local x=
	for x in $(sed -n -e "s/^dependency_libs=\'\(.*\)'\$/\1/p" "$1"); do
		case "${x}" in
			/*)
				if [ ! -e "${x}" ]; then
					echo "(missing ${x})"
					return 0
				fi
				;;
		esac
	done

	return 1
}

# Return a $PATH style variable based on ld.so.conf
read_so_conf() {
	local line=
	while read line; do
		case "${line}" in
			"#"*) ;;
			*) printf ":%s" "${line}";;
		esac
	done < /etc/ld.so.conf
}

# Check to see if we have already scanned a dir or not
scanned() {
	local dir=$1 IFS=:
	set -- ${scanned}

	while [ -n "$1" ]; do
		[ "$1" = "$dir" ] && return 0
		shift
	done

	scanned="${scanned}${scanned:+:}${dir}"
	return 1
}

# Hit the portage vdb to work out our ebuilds
# If everything is 100% then this happens in one very fast pass
# Otherwise we have to take the slow approach to inform the user which files
# are orphans
get_exact_ebuilds() {
	local regex= ebuilds= x= IFS=:
	set -- $@
	IFS=" "

	# Hit the vdb in one go - this is fast!
	regex=$(printf "%s|" "$@")
	regex=${regex%*|}
	find /var/db/pkg -name CONTENTS | \
		xargs egrep "^obj (${regex}) " | \
		sed -e 's,/var/db/pkg/\(.*\/.*\)/CONTENTS:.*,=\1,g' | \
		tr '\n' ' '
}

# Get our args
libs=
exact=false
order=true
while [ -n "$1" ]; do
	case "$1" in
		--*=*)
			arg1=${1%%=*}
			arg2=${1#*=}
			shift
			set -- ${arg1} ${arg2} $@
			continue
		;;
		-h|--help) print_usage; exit 0;;
		-L|--library|--soname|--soname-regexp)
			if [ -z "$2" ]; then
				eerror "Missing expected argument to $1"
				exit 1
			fi
			libs="${libs}${libs:+ }$2"
			shift
		;;
		-e|--exact) exact=true;;
		-X|--package-names) ;; #compat
		--) shift; emerge_opts="$@"; break;;
		*) eerror "$0: unknown option $1"; exit 1;;
	esac
	shift
done

einfo "Configuring search environment for ${appname}"
# OK, this truely sucks. Paths can have spaces in, but our config format
# is space separated?
sdirs=$(unset SEARCH_DIRS; portageq envvar SEARCH_DIRS)
sdirs_mask=$(unset SEARCH_DIRS_MASK; portageq envvar SEARCH_DIRS_MASK)
ld_mask=$(unset LD_LIBRARY_MASK; portageq envvar LD_LIBRARY_MASK)

if [ -d /etc/revdep-rebuild ]; then
	for x in /etc/revdep-rebuild/*; do
		sdirs="${sdirs}${sdirs:+ }$(unset SEARCH_DIRS; . "${x}"; echo "${SEARCH_DIRS}")"
		sdirs_mask="${sdirs_mask}${sdirs_mask:+ }$(unset SEARCH_DIRS_MASK; . "${x}" ; echo "${SEARCH_DIRS_MASK}")"
		ld_mask="${ld_mask}${ld_mask:+ }$(unset LD_LIBRARY_MASK; . "${x}"; echo "${LD_LIBRARY_MASK}")"
	done
else
	sdirs="${sdirs}${sdirs:+ }/bin /sbin /usr/bin /usr/sbin /lib* /usr/lib*"
	sdirs_mask="${sdirs_mask}${sdirs_mask:+ }/opt/OpenOffice /usr/lib/openoffice"
	ld_mask="${ld_mask}${ld_mask:+ }libodbcinst.so libodbc.so libjava.so libjvm.so"
fi

sdirs=$(find ${sdirs} -type d)

einfo "Starting scan"
eindent
# Mark our masked dirs already scanned
scanned=
for dir in ${sdirs_mask}; do
	scanned "${dir}"
done

# Now scan our dirs
for dir in ${sdirs}; do
	scanned "${dir}" && continue

	einfo "in ${dir}"
	eindent
	for x in "${dir}"/*; do
		[ -d "${x}" ] && continue
		[ -L "${x}" ] && continue

		scan=true
		process=false
		reason=
		case "${x}" in
			*.so|*.so.*) process=true;;
			*.la)
				scan=false
				if [ -z "${libs}" ]; then
					reason=$(la_broken "${x}")
					[ $? = 0 ] && process=true
				fi
				;;
		esac
		[ -x "${x}" ] && ${scan} && process=true
		${process} || continue

		if ${scan}; then
			process=false
			if [ -n "${libs}" ]; then
				for lib in ${libs}; do
					if [ "${lib#/}" != "${lib}" ]; then
						# If lib starts with / then check if the exact
						# lib is linked
						elf_linked "${x}" "${lib}" || continue
					fi
					if elf_needed "${x}" ${lib}; then
						process=true
						break
					fi
				done
			else
				reason=$(elf_broken "${x}")
				[ $? = 0 ] && process=true
			fi
		fi

		${process} || continue
		einfo "found ${x} ${reason}"
		files="${files}${files:+:}${x}"
	done
	eoutdent
done
eoutdent

if [ -z "${files}" ]; then
	if [ -z "${libs}" ]; then
		einfo "Nothing found that needs rebuilding"
	else
		einfo "No dynamic binaries found with these libraries"
	fi
	exit 0
fi

einfo "Assigning files to packages"
eindent
ebuilds=$(get_exact_ebuilds "${files}")

if [ -z "${ebuilds}" ]; then
	eerror "No packages own these files"
	exit 1
fi

# Work out the best visible package for the slot
if ! ${exact}; then
	root=$(portageq envvar ROOT)
	root=${root:-/}

	set -- ${ebuilds}
	ebuilds=
	for x in "$@"; do
		x=${x#=*}
		pkg=${x%-r[0-9]*}
		pkg=${pkg%-*}
		slot=$(cat "/var/db/pkg/${x}/SLOT")
        ebd=$(portageq best_visible "${root}" "${pkg}:${slot}")
		if [ -z "${ebd}" ]; then
			eerror "Cannot find an ebuild visible for ${x}"
		else
			ebuilds="${ebuilds}${ebuilds:+ }=${ebd}"
		fi
	done
fi
eoutdent

# Work out the build order
if ${order}; then
	einfo "Ordering packages"
	order="$(EMERGE_DEFAULT_OPTS="" \
		emerge --nospinner --pretend --deep --quiet ${ebuilds})"
	if [ $? = 0 ]; then
		ebuilds=$(echo "${order}" | \
			sed -e 's:^\[.*\] \([^ ]*\)[ ].*$:=\1:' | \
			grep -F "$(printf "%s\n" ${ebuilds})" | \
			tr '\n' ' ')
	else
		eerror "Unable to order packages!"
	fi
fi

if [ -z "${ebuilds}" ]; then
	eerror "Don't know how to find which package owns what file :/"
	exit 1
fi

echo
einfo "About to execute"
echo "emerge --oneshot ${emerge_opts} ${ebuilds}"
echo

i=5
printf "in"
while [ ${i} -gt 0 ]; do
	printf " ${i}"
	sleep 1
	i=$((${i} - 1))
done
printf "\n\n"

EMERGE_DEFAULT_OPTS="" emerge --oneshot ${emerge_opts} ${ebuilds}
retval=$?

if [ "${retval}" = 0 ]; then
	einfo "All done"
	exit 0
fi

eerror "There was an error trying to emerge the broken packages"
exit "${retval}"