Deprecate MFC rather than completely remove.

Author: nickclark2016

modules/vstudio/tests/vc2010/test_config_props.lua

@@ -184,6 +184,17 @@
 		]]
 	end
 
+	function suite.useOfMfc_onDynamicRuntimeViaFlag()
+		flags { "MFC" }
+		prepare()
+		test.capture [[
+<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
+	<ConfigurationType>Application</ConfigurationType>
+	<UseDebugLibraries>false</UseDebugLibraries>
+	<UseOfMfc>Dynamic</UseOfMfc>
+		]]
+	end
+
 	function suite.useOfMfc_onStaticRuntime()
 		mfc "On"
 		staticruntime "On"
@@ -195,7 +206,19 @@
 	<UseOfMfc>Static</UseOfMfc>
 		]]
 	end
-
+	
+	function suite.useOfMfc_onStaticRuntimeViaFlag()
+		flags { "MFC" }
+		staticruntime "On"
+		prepare()
+		test.capture [[
+<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
+	<ConfigurationType>Application</ConfigurationType>
+	<UseDebugLibraries>false</UseDebugLibraries>
+	<UseOfMfc>Static</UseOfMfc>
+		]]
+	end
+	
 	function suite.useOfMfc_forceStatic()
 		mfc "Static"
 		prepare()

src/_premake_init.lua

@@ -339,6 +339,7 @@
 			"FatalLinkWarnings",
 			"LinkTimeOptimization",
 			"Maps",
+			"MFC",
 			"MultiProcessorCompile",
 			"No64BitChecks",
 			"NoCopyLocal",
@@ -1088,6 +1089,14 @@
 		tokens = true,
 	}
 
+	api.deprecateValue("flags", "MFC", 'Use `mfc` instead.',
+	function(value)
+		mfc("On")
+	end,
+	function(value)
+		mfc("Off")
+	end)
+
 	api.deprecateField("sysincludedirs", 'Use `externalincludedirs` instead.',
 	function(value)
 		externalincludedirs(value)

website/docs/flags.md

@@ -16,6 +16,7 @@ flags { "flag_list" }
 | FatalWarnings         | Treat all warnings as errors; equivalent to FatalCompileWarnings, FatalLinkWarnings |
 | LinkTimeOptimization  | Enable link-time (i.e. whole program) optimizations.                |
 | Maps                  | Enable Generate Map File for Visual Studio                          |
+| MFC                   | Enable support for Microsoft Foundation Classes. Deprecated in Premake 5.0.0-beta4. |
 | MultiProcessorCompile | Enable Visual Studio to use multiple compiler processes when building. |
 | No64BitChecks         | Disable 64-bit portability warnings.                                |
 | NoBufferSecurityCheck | Turn off stack protection checks.                                   |