#!/bin/sh -e

# checkapk - find ABI breakages in package upgrades
# Copyright (c) 2012 Natanael Copa <natanael.copa@gmail.com>
#
# Distributed under GPL-2
#

program_version=@VERSION@
datadir=@datadir@

if ! [ -f "$datadir/functions.sh" ]; then
	echo "$datadir/functions.sh: not found" >&2
	exit 1
fi
. "$datadir/functions.sh"

case "$(tar --version)" in
*GNU*) tar_flavor=GNU;;
*libarchive*) tar_flavor=libarchive;;
*busybox*) tar_flavor=busybox;;
*) die 'unknown tar flavor';;
esac
: ${APK:="/sbin/apk"}
if command -v abipkgdiff >/dev/null 2>&1; then
	abigail=1
fi

subpackage_types_has() {
	local i
	for i in $subpackages; do
		local _name="${i%%:*}"
		[ "$1" = "${_name##*-}" ] && return 0
	done
	return 1
}

list_has() {
	local needle="$1"
	local i
	shift
	for i in $@; do
		[ "$needle" = "$i" ] && return 0
		[ "$needle" = "!$i" ] && return 1
	done
	return 1
}

usage() {
	cat >&2 <<-__EOF__
		$program $program_version - find ABI breakages in package upgrades
		Usage: $program

		Run in the directory of a built package.

	__EOF__
}

fetch_old() {
	if ! $APK fetch --stdout --repositories-file "$tmpdir/repositories" "$1" > old.apk; then
		warning "could not download $1 (network error or new package)"
		return 1
	else
		[ -e old.apk ] || die "can't find old apk old.apk"
		return 0
	fi
}

fetch_new() {
	local i
	for i in "$PKGDEST/$1" "$REPODEST/$repo/$CARCH/$1" "$startdir/$1"; do
		i="$i-$pkgver-r$pkgrel.apk"
		if [ -f "$i" ]; then
			echo "$i"
			return 0
		fi
	done
	[ -f "$i" ] || die "can't find new apk $1"
}

pkginfo() {
	local apk="$1"
	local filename="$2"

	tar -zxf "$apk" .PKGINFO
	mv .PKGINFO .PKGINFO.orig
	grep -E \
		'^(depend|provides|provider|replaces|triggers|install_if)' \
		.PKGINFO.orig | sort > "$filename"
	touch -r .PKGINFO.orig "$filename"
	rm .PKGINFO.orig
}

filelist() {
	local apk="$1"
	local filename="$2"
	local tar_fmt

	case "$tar_flavor" in
	GNU)
		# -rw-r--r-- root/root       737 2019-06-14 20:45 .PKGINFO
		# lrwxrwxrwx root/root         0 2019-09-13 06:01 usr/lib/libixion-0.15.so.0 -> libixion-0.15.so.0.0.0
		# hrwxr-xr-x root/root         0 2019-04-22 10:26 usr/bin/python3.6 link to usr/bin/python3.6m
		tar_fmt='{ printf "%s %s ", $1, $2 }
			/^l/ { printf "%s -> ", $(NF-2) }
			/^h/ { printf "%s -> ", $(NF-3) }
			{ print $NF }';;
	busybox)
		# -rw-r--r-- root/root       737 2019-06-14 20:45:29 .PKGINFO
		# lrwxrwxrwx root/root         0 2019-09-13 06:01:49 usr/lib/libixion-0.15.so.0 -> libixion-0.15.so.0.0.0
		# -rwxr-xr-x root/root         0 2019-04-22 10:26:45 usr/bin/python3.6 -> usr/bin/python3.6m
		tar_fmt='{ printf "%s %s ", $1, $2 }
			/ -> / { printf "%s -> ", $(NF-2) }
			{ print $NF }';;
	libarchive)
		# -rw-r--r--  0 root   root      737 Jun 14 15:45 .PKGINFO
		# lrwxrwxrwx  0 root   root        0 Sep 13 01:01 usr/lib/libixion-0.15.so.0 -> libixion-0.15.so.0.0.0
		# hrwxr-xr-x  0 root   root        0 Oct  1 22:40 usr/bin/python3.6m link to usr/bin/python3.6
		tar_fmt='{ printf "%s %s/%s ", $1, $3, $4 }
			/^l/ { printf "%s -> ", $(NF-2) }
			/^h/ { printf "%s -> ", $(NF-3) }
			{ print $NF }';;
	esac

	tar -ztvf "$apk" | grep -ve ' \.SIGN\.' \
		| awk "$tar_fmt" \
		| sort -k 3,3 > "$filename"
}

abigail_pre() {
	[ -n "$abigail" ] || return 0

	# This assumes one of each, which should generally be the case.
	for i in $subpackages; do
		case "$i" in
		*-dbg) dbg2="$i";;
		*-dev) dev2="$i";;
		esac
	done

	if [ -n "$dbg2" ]; then
		if fetch_old "$dbg2"; then
			dbg1="$dbg2.old.apk"
			mv old.apk "$dbg1"
		fi
		dbg2="$(fetch_new "$dbg2")"
	fi

	if [ -n "$dev2" ]; then
		if fetch_old "$dev2"; then
			dev1="$dev2.old.apk"
			mv old.apk "$dev1"
		fi
		dev2="$(fetch_new "$dev2")"
	fi
}

abigail() {
	[ -n "$abigail" ] || return 0
	[ -n "$oldapk" ] || return 0
	case "$newapk" in
	"$dbg2"|"$dev2") return 0;;
	esac

	set +e
	abipkgdiff \
		${dbg1:+--debug-info-pkg1 "$dbg1"} \
		${dbg2:+--debug-info-pkg2 "$dbg2"} \
		${dev1:+--devel-pkg1 "$dev1"} \
		${dev2:+--devel-pkg2 "$dev2"} \
		--leaf-changes-only \
		--impacted-interfaces \
		--show-bytes \
		"$oldapk" "$newapk"
	rc=$?
	set -e

	if [ "$((rc & 4))" -eq 4 ]; then
		warning "Abigail detected a possibly incompatible change."
	elif [ "$((rc & 8))" -eq 8 ]; then
		error "Abigail detected an incompatible change."
	fi
}

check_soname() {
	local soname sover_old basename soname_new sover_new
	local rdeps real_rdeps i self j

	soname="$1"
	sover_old="${soname#*=}"
	soname="${soname%=*}"
	basename="${soname%%.so*}.so"
	soname_new="$(grep -F "provides = $basename" \
		"pkginfo-$_pkgname-new" | cut -d ' ' -f 3)"
	sover_new="${soname_new#*=}"
	soname_new="${soname_new%=*}"

	if [ -z "$soname_new" ]; then
		warning "SONAME moved or deleted: $soname"
	elif [ "$soname" != "$soname_new" ]; then
		warning "SONAME changed: $soname=$sover_old"
		warning2 "-> $soname_new=$sover_new"
	elif [ "$sover_old" != "$sover_new" ]; then
		warning "SOVER changed: $soname=$sover_old"
		warning2 "-> $soname_new=$sover_new"
	fi

	rdeps="$($APK search --repositories-file "$tmpdir/repositories" \
		--rdepends --quiet --exact "$soname" | sort -u)"

	real_rdeps=
	for i in $rdeps; do
		self=0
		for j in $pkgname $subpackages; do
			[ "$i" = "$j" ] || continue
			self=1
			break
		done
		[ "$self" -eq 0 ] && real_rdeps="$real_rdeps
$i"
	done

	if [ -n "$real_rdeps" ]; then
		warning "dependents on $soname:"
		# (warning2)                                  >>> WARNING:
		printf '%s\n' "$real_rdeps" | sed '/^$/d; s/^/             /' >&2
	else
		msg "No dependents on $soname."
	fi
}

if [ $# -gt 0 ]; then
	usage
	exit 2
fi

if ! [ -f "$ABUILD_CONF" ] && ! [ -f "$ABUILD_USERCONF" ]; then
	die "no abuild.conf found"
fi

if ! [ -f APKBUILD ]; then
	die 'must be run in the directory of a built package'
fi

if ! [ -n "$CARCH" ]; then
	die "failed to detect CARCH"
fi

. ./APKBUILD
if [ -n "$DEFAULT_DBG" ] \
		&& ! subpackage_types_has "dbg" \
		&& ! list_has "!dbg" $options \
		&& [ "$arch" != "noarch" ]; then
	subpackages="$pkgname-dbg $subpackages"
fi

startdir="$PWD"
repodir="${startdir%/*}"
repo="${repodir##*/}"
tmpdir=$(mktemp -d -t checkpkg-script.XXXXXX)
trap "rm -rf '$tmpdir'" INT EXIT
cd "$tmpdir" || die "failed to create temp dir"

# generate a temp repositories file with only the http(s) repos
grep -E "^https?:" /etc/apk/repositories > "$tmpdir/repositories"

abigail_pre

for i in $pkgname $subpackages; do
	_pkgname=${i%%:*}

	newapk="$(fetch_new "$_pkgname")"

	case "$newapk" in
	"$dbg2")
		oldapk="$dbg1"
		;;
	"$dev2")
		oldapk="$dev1"
		;;
	*)
		oldapk=old.apk
		if ! fetch_old "$_pkgname"; then
			oldapk=
		fi
		;;
	esac

	if [ -n "$oldapk" ]; then
		pkginfo "$oldapk" "pkginfo-$_pkgname-old"
		filelist "$oldapk" "filelist-$_pkgname-old"
		touch -r "pkginfo-$_pkgname-old" "filelist-$_pkgname-old"
	else
		touch "filelist-$_pkgname-old"
		touch "pkginfo-$_pkgname-old"
	fi

	pkginfo "$newapk" "pkginfo-$_pkgname-new"
	filelist "$newapk" "filelist-$_pkgname-new"
	touch -r "pkginfo-$_pkgname-new" "filelist-$_pkgname-new"

	diff -u "filelist-$_pkgname-old" "filelist-$_pkgname-new" || true
	diff -u "pkginfo-$_pkgname-old" "pkginfo-$_pkgname-new" | tee pkginfo-diff

	soname=
	for soname in $(awk '/^-provides = so:/ { print $3 }' pkginfo-diff); do
		check_soname "$soname"
	done
	[ -n "$soname" ] || msg "No soname differences for $_pkgname."

	if grep -q '^provides = so:' "pkginfo-$_pkgname-new"; then
		abigail
	fi

	rm -f old.apk
done