package/polkit: needs glibc

The recent bump of polkit introduced a version that now unconditionally
uses glibc-specific functions from the getnetgrent() familly, which are
not available on musl or uClibc-ng.

Hide away polkit when the C library is not glibc.

Propagate the dependency to packages that select polkit: udisks and
systemd. For systemd, add a comment.

Fixes:
    http://autobuild.buildroot.org/results/d78/d783e6db60b187aa591f4b0150c590ab3aa5252f/ (musl)
    http://autobuild.buildroot.org/results/ba5/ba5da960c70c765bee753a79b9ad2c10967d05d6/ (uclibc)
    [...]

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Marek Belisko <marek.belisko@open-nandra.com>
Cc: Maxime Hadjinlian <maxime.hadjinlian@gmail.com>
Cc: Artem Panfilov <apanfilov@spectracom.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/polkit/Config.in

@@ -1,8 +1,9 @@
 config BR2_PACKAGE_POLKIT
 	bool "polkit"
-	depends on BR2_USE_WCHAR # libglib2
-	depends on BR2_TOOLCHAIN_HAS_THREADS # libglib2
 	depends on BR2_USE_MMU # libglib2
+	depends on BR2_TOOLCHAIN_HAS_THREADS # libglib2
+	depends on BR2_TOOLCHAIN_USES_GLIBC
+	depends on BR2_USE_WCHAR # libglib2
 	select BR2_PACKAGE_LIBGLIB2
 	select BR2_PACKAGE_EXPAT
 	help

package/systemd/Config.in

@@ -216,6 +216,7 @@ config BR2_PACKAGE_SYSTEMD_NETWORKD
 
 config BR2_PACKAGE_SYSTEMD_POLKIT
 	bool "enable polkit support"
+	depends on BR2_TOOLCHAIN_USES_GLIBC # polkit
 	select BR2_PACKAGE_POLKIT
 	help
 	  If enabled, systemd is built with polkit support and policy
@@ -225,6 +226,9 @@ config BR2_PACKAGE_SYSTEMD_POLKIT
 
 	  http://wiki.freedesktop.org/www/Software/polkit/
 
+comment "polkit support needs a glibc toolchain"
+	depends on !BR2_TOOLCHAIN_USES_GLIBC
+
 config BR2_PACKAGE_SYSTEMD_QUOTACHECK
 	bool "enable quotacheck tools"
 	help

package/udisks/Config.in

@@ -2,9 +2,9 @@ config BR2_PACKAGE_UDISKS
 	bool "udisks"
 	depends on BR2_PACKAGE_HAS_UDEV
 	depends on BR2_TOOLCHAIN_HAS_THREADS # dbus-glib -> glib2
+	depends on BR2_TOOLCHAIN_USES_GLIBC # polkit, lvm2
 	depends on BR2_USE_MMU # lvm2
 	depends on !BR2_STATIC_LIBS # lvm2
-	depends on !BR2_TOOLCHAIN_USES_MUSL # lvm2
 	depends on BR2_USE_WCHAR # dbus-glib -> glib2
 	select BR2_PACKAGE_DBUS
 	select BR2_PACKAGE_DBUS_GLIB
@@ -40,7 +40,7 @@ comment "udisks needs udev /dev management"
 	depends on BR2_USE_MMU
 	depends on !BR2_PACKAGE_HAS_UDEV
 
-comment "udisks needs a glibc or uClibc toolchain w/ wchar, threads, dynamic library"
+comment "udisks needs a glibc toolchain w/ wchar, threads, dynamic library"
 	depends on BR2_USE_MMU
 	depends on !BR2_USE_WCHAR || !BR2_TOOLCHAIN_HAS_THREADS || \
-		BR2_STATIC_LIBS || BR2_TOOLCHAIN_USES_MUSL
+		BR2_STATIC_LIBS || !BR2_TOOLCHAIN_USES_GLIBC