#!/bin/bash
# Spit out a portage-compatible list of packages to build because of lib
# breakages.

print_usage() {
cat << EOF
Usage: $0 [OPTIONS]

Lists packages broken by library changes, upgrades, and missing dependencies.

  -h, --help           Print this usage
  -e, --exact          Emerge based on exact package version
  -q, --quiet          Be less verbose (also passed to emerge command)
  -u, --no-util UTIL   Do not use features provided by UTIL
      --no-util=UTIL   UTIL can be one of portage-utils, pkgcore, or equery
                       or it can be a *quoted* space-delimited list.
  -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)
  -b, --check-linking  Check dynamic linking for binaries
  -l, --check-libtool  Check *.la files for missing dependencies

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

Report bugs to <http://bugs.gentoo.org>
EOF
}
get_missing_sonames() {
	local soname IFS=$'\n,' list=($(scanelf -BLpF%n#F))
	list=($(sort -u <<< "${list[*]}"))
	for soname in ${list[@]}; do
		[[ -e $soname ]] || echo $soname
	done | sort -u
}
check_bins() {
	local missing_sonames broken_pkgs bin libs pv p
	missing_sonames=$(get_missing_sonames)
	if [[ $missing_sonames ]] &&
		broken_pkgs=$(scanelf -LBpF "%F %n" | grep -F "$missing_sonames"); then
		get_packages $(
			while read bin libs; do
				feedback=$(grep -oF "$missing_sonames" <<< "$libs")
				feedback="${feedback##[[:space:]]}"; feedback="${feedback%%[[:space:]]}"
				echo "$bin is missing ${feedback//[[:space:]]/ and }" >&2
				echo "$bin"
			done <<< "$broken_pkgs"
		) | sort -u | slot
	else
		echo "Dynamic linking is consistent" >&2
	fi
}
get_all_las() {
	local IFS paths
	paths=(
		/lib*
		/usr/lib*
		$(sed '/^#/d;s/#.*$//' < /etc/ld.so.conf | tr -s '/')
		$(scanelf -BlpF%F | sed 's:/[^/]*$::' | tr -s '/')
	)
	IFS=$'\n'
	paths=($(sort -u <<< "${paths[*]%/}"))
	find -L ${paths[@]} -type f -name '*.la' 2> /dev/null | sort -u
}
get_dependency_libs() {
	awk -F"[=']" '/^dependency_libs/{
		gsub("^-[^[:space:]]*", "", $NF);
		gsub("[[:space:]]-[^[:space:]]*", "", $NF);
		print $NF
	}' "$@"
}
check_las() {
	local oIFS="$IFS"
	local IFS
	local broken_las=($(
		while read la; do
			deps=($(get_dependency_libs "$la"))
			(( ${#deps[@]} > 0)) || continue
			IFS=$'\n'
			deps=($(sort -u <<< "${deps[*]}"))
			IFS="$oIFS"
			for dep in ${deps[@]}; do
				[[ $dep = /* && ! -e $dep ]] || continue
				echo "$la is missing $dep" >&2
				echo "$la"
			done
		done < <(get_all_las) | sort -u
	))
	IFS=$'\n'
	if (( ${#broken_las[@]} > 0)); then
		get_packages <<< "${broken_las[*]}" | sort -u | slot
	else
		echo "No dependencies missing from .la files" >&2
	fi
}
slot() {
	while read pv; do
		p="${pv%%-r[[:digit:]]*}"
		p="${p%-*}"
		echo "$p:$(</var/db/pkg/$pv/SLOT)"
	done
}
get_opts(){
	local x
	while getopts "behlqL:u:" opt; do
		case "$opt" in
			L) SONAME="$OPTARG"; unset SEARCH_BROKEN;;
			b) checks+=(linking);;
			e) unset PACKAGE_NAMES;;
			h) print_usage; exit 0;;
			l) checks+=(libtool);;
			q) quiet=1; EMERGE_OPTIONS+=" $opt";;
			u) avoid_utils+=" $opt ";; # TODO: Check validity
		esac
		x=$OPTIND
	done
	shift $((x-1))
}
validate_arg() {
	[[ $1 && $1 != -* ]] || die 1 "Missing expected argument to $1"
}
get_args() {
	declare avoid_utils checks
	if [[ ! $1 ]]; then print_usage; exit 0; fi
	while [[ $1 ]]; do
		case $1 in
			-[^-]*)       get_opts "$1";;
			--help)       print_usage; exit 0;;
			--exact)      slot() { while read pv; do echo "=$pv"; done };;
			--quiet)      quiet=1;;
			--library=*)  search_lib="${1#*=}";;
			--library)    validate_arg "$1"; shift; search_lib="$1";;
			--no-util=*)  avoid_utils+=" ${1#*=} ";; # TODO: Check validity
			--no-util)    validate_arg "$1"; shift; avoid_utils+=" $1 ";;
			--check-linking) checks+=(linking);;
			--check-libtool) checks+=(libtool);;
			--)           break;;
			*)            echo "Invalid parameter $1:" >&2; print_usage; exit 1;;
		esac
		shift
	done
	if [[ avoid_utils != *portage-utils* ]] && hash qfile 2> /dev/null; then
		get_packages() { qfile -qvC "$@"; }
	elif [[ avoid_utils != *pkgcore* ]] && hash pquery 2> /dev/null; then
		get_packages() { local IFS=,; pquery --nocolor --owns="$*"; }
	elif [[ avoid_utils != *equery* ]] && hash equery 2> /dev/null; then
		get_packages() { equery -q -C b $@; }
	else
		get_packages() {
			local IFS=$'\n'
			find /var/db/pkg -name CONTENTS -print0 |
				xargs -0 grep -Fl "$*" |
				sed 's:/var/db/pkg/\(.*\)/CONTENTS:=\1:'
		}
	fi
	for check in ${checks[@]}; do
		case $check in
			linking) check_bins;;
			libtool) check_las;;
		esac
	done
}
get_args "$@"