makepkg: add libdepends support

The user adds libaries to the depends array without a version. These
must end with .so.
Example: depends=(glibc libc.so)

find_libdepends() looks for ELF files (not symlinks because these could
point outside of pkgdir) in $pkgdir, extracts the library sonames the
binary links to and outputs depends seperated by spaces.
This list contains all libraries needed by the package.
Example: libfoo.so=3-64

write_pkginfo() only keeps .so depends with version information and warns
the user about unneded ones.

Support-by: Thomas Bächler <thomas@archlinux.org>
Support-by: Christoph Schied <Christoph.Schied@uni-ulm.de>
Signed-off-by: Florian Pritz <bluewind@server-speed.net>

1 files changed, 40 insertions, 1 deletions

diff --git a/scripts/makepkg.sh.in b/scripts/makepkg.sh.in
index 6855aa6f..34be1e69 100644
--- a/scripts/makepkg.sh.in
+++ b/scripts/makepkg.sh.in
@@ -932,6 +932,31 @@ tidy_install() {
 	fi
 }
 
+find_libdepends() {
+	local libdepends
+	find "$pkgdir" -type f -perm -u+x | while read filename
+	do
+		# get architecture of the file; if soarch is empty it's not an ELF binary
+		soarch=$(LC_ALL=C readelf -h "$filename" 2>/dev/null | sed -n 's/.*Class.*ELF\(32\|64\)/\1/p')
+		[ -n "$soarch" ] || continue
+		# process all libraries needed by the binary
+		for sofile in $(LC_ALL=C readelf -d "$filename" 2>/dev/null | sed -nr 's/.*Shared library: \[(.*)\].*/\1/p')
+		do
+			# extract the library name: libfoo.so
+			soname="${sofile%%\.so\.*}.so"
+			# extract the major version: 1
+			soversion="${sofile##*\.so\.}"
+			if in_array "${soname}" ${depends[@]}; then
+				if ! in_array "${soname}=${soversion}-${soarch}" ${libdepends[@]}; then
+					# libfoo.so=1-64
+					echo "${soname}=${soversion}-${soarch}"
+					libdepends=(${libdepends[@]} "${soname}=${soversion}-${soarch}")
+				fi
+			fi
+		done
+	done
+}
+
 find_libprovides() {
 	local libprovides
 	find "$pkgdir" -type f -name \*.so\* | while read filename
@@ -988,7 +1013,6 @@ write_pkginfo() {
 	[[ $license ]]    && printf "license = %s\n"   "${license[@]}"
 	[[ $replaces ]]   && printf "replaces = %s\n"  "${replaces[@]}"
 	[[ $groups ]]     && printf "group = %s\n"     "${groups[@]}"
-	[[ $depends ]]    && printf "depend = %s\n"    "${depends[@]}"
 	[[ $optdepends ]] && printf "optdepend = %s\n" "${optdepends[@]}"
 	[[ $conflicts ]]  && printf "conflict = %s\n"  "${conflicts[@]}"
 	[[ $backup ]]     && printf "backup = %s\n"    "${backup[@]}"
@@ -996,7 +1020,22 @@ write_pkginfo() {
 	local it
 
 	libprovides=$(find_libprovides)
+	libdepends=$(find_libdepends)
 	provides=("${provides[@]}" ${libprovides})
+	depends=("${depends[@]}" ${libdepends})
+
+	for it in "${depends[@]}"; do
+		if [[ $it = *.so ]]; then
+			# check if the entry has been found by find_libdepends
+			# if not, it's unneeded; tell the user so he can remove it
+			if [[ ! $libdepends =~ (^|\s)${it}=.* ]]; then
+				error "$(gettext "Can't find library listed in \$depends: %s")" "$it"
+				return 1
+			fi
+		else
+			echo "depend = $it"
+		fi
+	done
 
 	for it in "${provides[@]}"; do
 		# ignore versionless entires (those come from the PKGBUILD)