Got cert tool building

This is progress towards fixing ValveSoftware#186.  However, I need some help
publishing/installing (or whatever it's called) properly, and
there is probably a better way to integrate with picojson than
using a git submodule.

.gitmodules

@@ -5,3 +5,6 @@
 [submodule "src/external/webrtc"]
 	path = src/external/webrtc
 	url = https://webrtc.googlesource.com/src
+[submodule "src/external/picojson"]
+	path = src/external/picojson
+	url = https://github.com/kazuho/picojson.git

CMakeLists.txt

@@ -46,6 +46,7 @@ option(BUILD_STATIC_LIB "Build the static link version of the client library" ON
 option(BUILD_SHARED_LIB "Build the shared library version of the client library" ON)
 option(BUILD_EXAMPLES "Build the included examples" OFF)
 option(BUILD_TESTS "Build crypto, pki and network connection tests" OFF)
+option(BUILD_TOOLS "Build cert management tool" OFF)
 option(LTO "Enable Link-Time Optimization" OFF)
 option(USE_STEAMWEBRTC "Build Google's WebRTC library to get ICE support for P2P" OFF)
 option(Protobuf_USE_STATIC_LIBS "Link with protobuf statically" OFF)

src/CMakeLists.txt

@@ -334,7 +334,19 @@ if (BUILD_STATIC_LIB)
 	set_clientlib_target_properties(GameNetworkingSockets_s)
 endif()
 
+#
+# Cert tool
+#
 if (BUILD_TOOLS)
+
+	# The cert tool requires picojson
+	# FIXME - somebody might be able to help figure this out
+	#find_package( picojson )
+	set(picojson_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/external/picojson)
+	if(NOT EXISTS ${picojson_SOURCE_DIR}/picojson.h)
+		message(FATAL_ERROR "picojson submodule not initialized.\n(Try: 'git submodule update src/external/picojson')" )
+	endif()
+
 	add_executable(steamnetworkingsockets_certtool
 		"steamnetworkingsockets/certtool/steamnetworkingsockets_certtool.cpp"
 		)
@@ -347,6 +359,7 @@ if (BUILD_TOOLS)
 	target_include_directories(steamnetworkingsockets_certtool PUBLIC
 		"$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/../include>"
 		"$<INSTALL_INTERFACE:$<INSTALL_PREFIX>/${CMAKE_INSTALL_INCLUDEDIR}/GameNetworkingSockets>"
+		${picojson_SOURCE_DIR}
 		)
 
 	target_include_directories(steamnetworkingsockets_certtool PRIVATE

vcpkg_ports/gamenetworkingsockets/portfile.cmake

@@ -13,13 +13,15 @@ if ( ( "${CRYPTO_BACKEND}" STREQUAL "" ) OR ( "openssl" IN_LIST FEATURES ) )
     set(CRYPTO_BACKEND "OpenSSL")
 endif()
 
-# 
+# Handle some simple options that we can just
+# pass straight through to cmake
 vcpkg_check_features(
     OUT_FEATURE_OPTIONS FEATURE_OPTIONS
     FEATURES
 		webrtc USE_STEAMWEBRTC
 		examples BUILD_EXAMPLES
 		tests BUILD_TESTS
+		tools BUILD_TOOLS
 )
 
 # Check static versus dynamic in the triple.  Our cmakefile can build both

vcpkg_ports/gamenetworkingsockets/vcpkg.json

@@ -24,6 +24,9 @@
 		},
 		"tests": {
 			"description": "Build the tests."
+		},
+		"tools": {
+			"description": "Build cert management tool."
 		}
 	}
-}
+}