abuild: automatically detect symlink targets in other subpackages

Automatically pull in dependencies for symlink targets provided by other
subpackages.

This is mainly for pulling in target of .so symlinks.

abuild.in

@@ -886,6 +886,19 @@ prepare_trace_rpaths() {
 	fi
 }
 
+# search for broken symlinks so we later can pull in proper depends
+prepare_symlinks() {
+	local dir="${subpkgdir:-$pkgdir}"
+	options_has "!tracedeps" && return 0
+	cd "$dir" || return 1
+	find -type l | while read symlink; do
+		if ! [ -e "$symlink" ]; then
+			echo "$symlink $(readlink $symlink)" \
+				>> "$controldir"/.symlinks
+		fi
+	done
+}
+
 # check if dir has arch specific binaries
 dir_has_arch_binaries() {
 	local dir="$1"
@@ -920,7 +933,8 @@ archcheck() {
 prepare_package() {
 	msg "Preparing ${subpkgname:+sub}package ${subpkgname:-$pkgname}..."
 	stripbin
-	prepare_metafiles && prepare_trace_rpaths || return 1
+	prepare_metafiles && prepare_trace_rpaths && prepare_symlinks \
+		|| return 1
 	archcheck
 }
 
@@ -1004,6 +1018,12 @@ trace_apk_deps() {
 		autodeps="$autodeps $found"
 	done
 
+	# symlink targets
+	for i in $(sort -u "$dir"/.symlinks-needs 2>/dev/null); do
+		msg "  added $i (symlink target)"
+		autodeps="$autodeps $i"
+	done
+
 	echo "# automatically detected:" >> "$dir"/.PKGINFO
 	if [ -f "$dir"/.provides-so ]; then
 		sed 's/^\(.*\) \([0-9].*\)/provides = so:\1=\2/' "$dir"/.provides-so \
@@ -1042,6 +1062,10 @@ scan_shared_objects() {
 	local name="$1" controldir="$2" datadir="$3"
 	local opt= i=
 
+	if [ "$arch" != "noarch" ]; then
+		return 0
+	fi
+
 	# allow spaces in paths
 	IFS=:
 	set -- $(find_scanelf_paths "$datadir")
@@ -1112,6 +1136,22 @@ scan_shared_objects() {
 	done > "$controldir"/.needs-so
 }
 
+# find which package provides file that symlink points to
+scan_symlink_targets() {
+	local name="$1" dir="$2" datadir="$3"
+	local symfile
+	cd "$datadir"
+	for symfile in "$pkgbasedir"/.control.*/.symlinks; do
+		[ -e "$symfile" ] || continue
+		while read symlink target; do
+			if [ -e "${symlink%/*}"/"$target" ]; then
+				local d="${symfile%/.symlinks}"
+				echo "$name" >> "$d"/.symlinks-needs
+			fi
+		done < "$symfile"
+	done
+}
+
 # read size in bytes from stdin and show as human readable
 human_size() {
 	awk '{  split("B KB MB GB TB PB", type)
@@ -1124,13 +1164,14 @@ create_apks() {
 	local file= dir= name= ver= apk= datadir= size=
 	getpkgver || return 1
 	mkdir -p "$PKGDEST"
-	if [ "$arch" != "noarch" ] && ! options_has "!tracedeps"; then
+	if ! options_has "!tracedeps"; then
 		for file in "$pkgbasedir"/.control.*/.PKGINFO; do
 			dir="${file%/.PKGINFO}"
 			name="$(pkginfo_val pkgname $file)"
 			datadir="$pkgbasedir"/$name
 			subpkgname=$name
 			scan_shared_objects "$name" "$dir" "$datadir"
+			scan_symlink_targets "$name" "$dir" "$datadir"
 		done
 	fi
 	for file in "$pkgbasedir"/.control.*/.PKGINFO; do