Merge pull request #82 from Blizzard/option-defaults-and-categories

add option default and category support.

src/base/help.lua

@@ -15,21 +15,38 @@
 		printf("Usage: premake5 [options] action [arguments]")
 		printf("")
 
+		-- filter all options by category.
+		local categories = {}
+		for option in premake.option.each() do
+			local cat = "OPTIONS - General"
+			if option.category then
+				cat = "OPTIONS - " .. options.category;
+			end
+
+			if categories[cat] then
+				table.insert(categories[cat], option)
+			else
+				categories[cat] = {option}
+			end
+		end
 
 		-- display all options
-		printf("OPTIONS")
-		printf("")
-		for option in premake.option.each() do
-			local trigger = option.trigger
-			local description = option.description
-			if (option.value) then trigger = trigger .. "=" .. option.value end
-			if (option.allowed) then description = description .. "; one of:" end
+		for k, options in pairs(categories) do
+			printf(k)
+			printf("")
+			for _, option in ipairs(options) do
+				local trigger = option.trigger
+				local description = option.description
+				if (option.value) then trigger = trigger .. "=" .. option.value end
+				if (option.allowed) then description = description .. "; one of:" end
 
-			printf(" --%-15s %s", trigger, description)
-			if (option.allowed) then
-				for _, value in ipairs(option.allowed) do
-					printf("     %-14s %s", value[1], value[2])
+				printf(" --%-15s %s", trigger, description)
+				if (option.allowed) then
+					for _, value in ipairs(option.allowed) do
+						printf("     %-14s %s", value[1], value[2])
+					end
 				end
+				printf("")
 			end
 			printf("")
 		end

src/base/option.lua

@@ -88,6 +88,11 @@
 
 		-- add it to the master list
 		premake.option.list[opt.trigger] = opt
+
+		-- if it has a default value, set it.
+		if opt.default and not _OPTIONS[opt.trigger] then
+			_OPTIONS[opt.trigger] = opt.default
+		end
 	end