package/doxygen: needs host gcc >= 4.9

host-doxygen use std::make_unique which is a C++14 feature and so not
available with host gcc 4.8 so add a Config.in.host for doxygen and add
host gcc 4.9 dependency to host-doxygen and sigrok C++ option

Fixes:
 - http://autobuild.buildroot.org/results/3ac78c5d4728287bafdfeb3a54f50eb193934b63

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/Config.in.host

@@ -14,6 +14,7 @@ menu "Host utilities"
 	source "package/dfu-util/Config.in.host"
 	source "package/dos2unix/Config.in.host"
 	source "package/dosfstools/Config.in.host"
+	source "package/doxygen/Config.in.host"
 	source "package/dtc/Config.in.host"
 	source "package/e2fsprogs/Config.in.host"
 	source "package/e2tools/Config.in.host"

package/doxygen/Config.in.host

@@ -0,0 +1,12 @@
+config BR2_PACKAGE_HOST_DOXYGEN
+	bool "host doxygen"
+	depends on BR2_HOST_GCC_AT_LEAST_4_9 # C++14
+	help
+	  Doxygen is the de facto standard tool for generating
+	  documentation from annotated C++ sources, but it also
+	  supports other popular programming languages such as C,
+	  Objective-C, C#, PHP, Java, Python, IDL (Corba, Microsoft,
+	  and UNO/OpenOffice flavors), Fortran, VHDL, Tcl, and to some
+	  extent D.
+
+	  http://www.doxygen.nl/

package/libsigrok/Config.in

@@ -26,13 +26,16 @@ config BR2_PACKAGE_LIBSIGROKCXX
 	bool "build C++ bindings"
 	depends on BR2_INSTALL_LIBSTDCPP
 	depends on BR2_TOOLCHAIN_GCC_AT_LEAST_4_9 # glibmm
+	depends on BR2_HOST_GCC_AT_LEAST_4_9 # host-doxygen
 	select BR2_PACKAGE_GLIBMM
+	select BR2_PACKAGE_HOST_DOXYGEN
 	help
 	  Build libsigrok C++ bindings as well.
 
-comment "C++ bindings need a toolchain w/ C++, gcc >= 4.9"
+comment "C++ bindings need a toolchain w/ C++, gcc >= 4.9, host gcc >= 4.9"
 	depends on !BR2_INSTALL_LIBSTDCPP || \
-		!BR2_TOOLCHAIN_GCC_AT_LEAST_4_9
+		!BR2_TOOLCHAIN_GCC_AT_LEAST_4_9 || \
+		!BR2_HOST_GCC_AT_LEAST_4_9
 
 endif