Add an 'extended' & 'uncached' sub-context to the context.

Context sensitive detokenization of Visual Studio rules property definitions.

src/actions/vstudio/vs2010_rules_props.lua

@@ -145,7 +145,15 @@
 
 	function m.commandLineTemplates(r)
 		if #r.buildcommands then
-			local cmds = os.translateCommands(r.buildcommands, p.WINDOWS)
+
+			-- create shadow context.
+			local env = p.rule.createEnvironment(r, "[%s]")
+			local ctx = p.context.extent(r, env)
+
+			-- now use the shadow context to detoken.
+			local cmds = os.translateCommands(ctx.buildcommands, p.WINDOWS)
+
+			-- write out the result.
 			cmds = table.concat(cmds, p.eol())
 			p.x('<CommandLineTemplate>%s</CommandLineTemplate>', cmds)
 		end
@@ -163,7 +171,12 @@
 
 	function m.executionDescription(r)
 		if r.buildmessage then
-			p.x('<ExecutionDescription>%s</ExecutionDescription>', r.buildmessage)
+			-- create shadow context.
+			local env = p.rule.createEnvironment(r, "[%s]")
+			local ctx = p.context.extent(r, env)
+
+			-- write out the result.
+			p.x('<ExecutionDescription>%s</ExecutionDescription>', ctx.buildmessage)
 		end
 	end
 
@@ -171,7 +184,14 @@
 
 	function m.outputs(r)
 		if #r.buildoutputs then
-			local outputs = table.concat(r.buildoutputs, ";")
+			-- create shadow context.
+			local pathVars = p.rule.createPathVars(r, "%%(%s)")
+			local ctx = p.context.extent(r, { pathVars = pathVars })
+
+			-- now use the shadow context to detoken.
+			local outputs = table.concat(ctx.buildoutputs, ";")
+
+			-- write out the result.
 			p.x('<Outputs>%s</Outputs>', path.translate(outputs))
 		end
 	end

src/base/context.lua

@@ -59,6 +59,31 @@
 	end
 
 
+--
+-- Create an extended and uncached context based on another context object.
+--
+-- @param baseContext
+--    The base context to extent
+-- @param newEnvVars
+--    An optional key-value environment table for token expansion; keys and
+--    values provided in this table will be available for tokens to use.
+-- @return
+--    A new context object.
+--
+
+	function context.extent(baseContext, newEnvVars)
+		local ctx = {}
+		ctx._ctx = baseContext
+		ctx.environ = newEnvVars or baseContext.environ
+		ctx.terms = {}
+		ctx._basedir = baseContext._basedir
+
+		setmetatable(ctx, context.__mt_uncached)
+
+		return ctx
+	end
+
+
 
 ---
 -- Add a new key-value pair to refine the context filtering.
@@ -204,7 +229,7 @@
 		local value = configset.fetch(ctx._cfgset, field, ctx.terms, ctx, onlylocal and ctx._cfgset)
 		if value then
 			-- store the result for later lookups
-			ctx[key] = value
+			rawset(ctx, key, value)
 		end
 
 		return value
@@ -214,3 +239,14 @@
 		__index = context.fetchvalue
 	}
 
+	context.__mt_uncached = {
+		__index =  function(ctx, key)
+			local field = p.field.get(key)
+			if not field then
+				return nil
+			end
+			local parent = rawget(ctx, '_ctx')
+			return configset.fetch(parent._cfgset, field, ctx.terms, ctx, nil)
+		end
+	}
+

src/base/detoken.lua

@@ -42,6 +42,9 @@
 			end
 		end
 
+		-- fetch the pathVars from the enviroment.
+		local envMap = environ.pathVars or {}
+
 		-- enable access to the global environment
 		setmetatable(environ, {__index = _G})
 
@@ -79,14 +82,14 @@
 				end
 			end
 
-			-- If this token is in my path variable mapping table, replace the
+			-- If this token is in my path variable mapping tables, replace the
 			-- value with the one from the map. This needs to go here because
 			-- I don't want to make the result relative, but I don't want the
 			-- absolute path handling below.
-
-			if varMap[token] then
+			local mapped = envMap[token] or varMap[token]
+			if mapped then
 				err    = nil
-				result = varMap[token]
+				result = mapped
 				if type(result) == "function" then
 					success, result = pcall(result, e)
 					if not success then

src/base/rule.lua

@@ -159,3 +159,51 @@
 			p.api.storeField(fld, value)
 		end
 	end
+
+
+
+---
+-- prepare an environment with the rule properties as global tokens,
+-- according to the format specified.
+--
+-- @param environ
+--    The environment table to fill up
+-- @param format
+--    The formatting to be used, ie "[%s]".
+---
+
+	function rule.prepareEnvironment(self, environ, format)
+		for _, def in ipairs(self.propertydefinition) do
+			environ[def.name] = string.format(format, def.name)
+		end
+	end
+
+	function rule.createEnvironment(self, format)
+		local environ = {}
+		rule.prepareEnvironment(self, environ, format)
+		return environ
+	end
+
+
+
+---
+-- prepare an table of pathVars with the rule properties as global tokens,
+-- according to the format specified.
+--
+-- @param pathVars
+--    The pathVars table to fill up
+-- @param format
+--    The formatting to be used, ie "%%(%s)".
+---
+
+	function rule.preparePathVars(self, pathVars, format)
+		for _, def in ipairs(self.propertydefinition) do
+			pathVars[def.name] = { absolute = true,  token = string.format(format, def.name) }
+		end
+	end
+
+	function rule.createPathVars(self, format)
+		local pathVars = {}
+		rule.preparePathVars(self, pathVars, format)
+		return pathVars
+	end