string.explode() gains 'maxTokens' argument.

src/actions/vstudio/vs2010_vcxproj.lua

@@ -1510,11 +1510,7 @@
 
 	function m.platformToolset(cfg)
 		local tool, version = p.config.toolset(cfg)
-		if version then
-			if tonumber(version:sub(1,3)) ~= nil then
-				version = "v" .. version
-			end
-		else
+		if not version then
 			local action = p.action.current()
 			version = action.vstudio.platformToolset
 		end

src/base/string.lua

@@ -29,13 +29,19 @@
 -- formed by splitting on boundaries formed by `pattern`.
 --
 
-	function string.explode(s, pattern, plain)
+	function string.explode(s, pattern, plain, maxTokens)
 		if (pattern == '') then return false end
 		local pos = 0
 		local arr = { }
 		for st,sp in function() return s:find(pattern, pos, plain) end do
 			table.insert(arr, s:sub(pos, st-1))
 			pos = sp + 1
+			if maxTokens ~= nil and maxTokens > 0 then
+				maxTokens = maxTokens - 1
+				if maxTokens == 0 then
+					break
+				end
+			end
 		end
 		table.insert(arr, s:sub(pos))
 		return arr

src/base/tools.lua

@@ -31,16 +31,22 @@
 
 	function p.tools.canonical(identifier)
 		local parts
-		if identifier:startswith("v") then
-			parts = { "msc", identifier:sub(2) }
-		elseif identifier:startswith("llvm-vs") then -- support LLVM toolset in VS
-			parts = { "msc", "LLVM-vs" .. identifier:sub(8) }
+		if identifier:startswith("v") then -- TODO: this should be deprecated?
+			parts = { "msc", identifier }
 		else
-			parts = identifier:explode("-")
+			parts = identifier:explode("-", true, 1)
 
-			-- hack to check for LLVM toolsets, which would be corrupted by the previous line
-			if parts[1] == "msc" and parts[2] == "llvm" and parts[3]:startswith("vs") then
-				parts = { parts[1], "LLVM-" .. parts[3] }
+			-- couple of little hacks here to fix up version names
+			if parts[2] ~= nil then
+				-- 'msc-100' is accepted, but the code expects 'v100'
+				if parts[1] == "msc" and tonumber(parts[2]:sub(1,3)) ~= nil then
+					parts[2] = "v" .. parts[2]
+				end
+
+				-- perform case-correction of the LLVM toolset
+				if parts[2]:startswith("llvm-vs") then
+					parts[2] = "LLVM-" .. parts[2]:sub(6)
+				end
 			end
 		end
 		return p.tools[parts[1]], parts[2]

tests/actions/vstudio/vc2010/test_platform_toolset.lua

@@ -96,14 +96,6 @@
 	end
 
 	function suite.canOverrideFromScript_withLLVM()
-		toolset "LLVM-vs2010"
-		prepare()
-		test.capture [[
-<PlatformToolset>LLVM-vs2010</PlatformToolset>
-		]]
-	end
-
-	function suite.canOverrideFromScript_withMscAndLLVM()
 		toolset "msc-llvm-vs2014_xp"
 		prepare()
 		test.capture [[