libpfm4: needs thread support

Fixes:

  http://autobuild.buildroot.net/results/73d736dd3c8a70358ef4b19a63dda46178cf8bf1/

Note that the propagation of the thread dependency to the oprofile
package is a little bit non standard, because oprofile selects libpfm4
only on the PowerPC architecture. So we ensure the thread dependency
is only enforced on PowerPC, and a separate comment is displayed when
thread support is not available, but the PowerPC architecture is used.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/libpfm4/Config.in

@@ -1,8 +1,12 @@
 config BR2_PACKAGE_LIBPFM4
 	bool "libpfm4"
 	depends on !BR2_avr32 # no perf_event_open
+	depends on BR2_TOOLCHAIN_HAS_THREADS
 	help
 	  A helper library to help encode Performance Events to use with
 	  Operating system kernels performance monitoring interfaces.
 
 	  http://perfmon2.sourceforge.net/
+
+comment "libpfm4 needs a toolchain w/ threads"
+	depends on !BR2_TOOLCHAIN_HAS_THREADS

package/oprofile/Config.in

@@ -6,6 +6,8 @@ config BR2_PACKAGE_OPROFILE
 	select BR2_PACKAGE_LIBPFM4 if BR2_powerpc
 	depends on BR2_INSTALL_LIBSTDCPP
 	depends on !BR2_aarch64 # binutils
+	# libpfm4 is needed on PowerPC, and requires thread support
+	depends on BR2_TOOLCHAIN_HAS_THREADS || !BR2_powerpc
 	help
 	  OProfile is a system-wide profiler for Linux systems,
 	  capable of profiling all running code at low overhead.
@@ -25,3 +27,7 @@ config BR2_PACKAGE_OPROFILE
 comment "oprofile needs a toolchain w/ C++"
 	depends on BR2_USE_MMU && !BR2_aarch64
 	depends on !BR2_INSTALL_LIBSTDCPP
+
+comment "oprofile needs a toolchain w/ threads on PPC"
+	depends on BR2_USE_MMU && BR2_powerpc
+	depends on !BR2_TOOLCHAIN_HAS_THREADS