Allow querying values without combining values from parent configs.

src/base/configset.lua

@@ -63,23 +63,31 @@
 --    the context filtering case-insensitive.
 -- @param ctx
 --    The context that will be used for detoken.expand
+-- @param origin
+--    The originating configset if set.
 -- @return
 --    The requested value.
 ---
 
-	function configset.fetch(cset, field, filter, ctx)
+	function configset.fetch(cset, field, filter, ctx, origin)
 		filter = filter or {}
 		ctx = ctx or {}
 
 		if p.field.merges(field) then
-			return configset._fetchMerged(cset, field, filter, ctx)
+			return configset._fetchMerged(cset, field, filter, ctx, origin)
 		else
-			return configset._fetchDirect(cset, field, filter, ctx)
+			return configset._fetchDirect(cset, field, filter, ctx, origin)
 		end
 	end
 
 
-	function configset._fetchDirect(cset, field, filter, ctx)
+	function configset._fetchDirect(cset, field, filter, ctx, origin)
+		-- If the originating configset hasn't been compiled, then the value will still
+		-- be on that configset.
+		if origin and origin ~= cset and not origin.compiled then
+			return configset._fetchDirect(origin, field, filter, ctx, origin)
+		end
+
 		local abspath = filter.files
 		local basedir
 
@@ -88,6 +96,8 @@
 		local n = #blocks
 		for i = n, 1, -1 do
 			local block = blocks[i]
+
+			if not origin or block._origin == origin then
 				local value = block[key]
 
 				-- If the filter contains a file path, make it relative to
@@ -108,20 +118,26 @@
 					if field.tokens and ctx.environ then
 						value = p.detoken.expand(value, ctx.environ, field, ctx._basedir)
 					end
-
 					return value
 				end
 			end
+		end
 
 		filter.files = abspath
 
 		if cset.parent then
-			return configset._fetchDirect(cset.parent, field, filter, ctx)
+			return configset._fetchDirect(cset.parent, field, filter, ctx, origin)
 		end
 	end
 
 
-	function configset._fetchMerged(cset, field, filter, ctx)
+	function configset._fetchMerged(cset, field, filter, ctx, origin)
+		-- If the originating configset hasn't been compiled, then the value will still
+		-- be on that configset.
+		if origin and origin ~= cset and not origin.compiled then
+			return configset._fetchMerged(origin, field, filter, ctx, origin)
+		end
+
 		local result = {}
 
 		local function remove(patterns)
@@ -146,7 +162,7 @@
 		end
 
 		if cset.parent then
-			result = configset._fetchMerged(cset.parent, field, filter, ctx)
+			result = configset._fetchMerged(cset.parent, field, filter, ctx, origin)
 		end
 
 		local abspath = filter.files
@@ -157,7 +173,7 @@
 		local n = #blocks
 		for i = 1, n do
 			local block = blocks[i]
-
+			if not origin or block._origin == origin then
 				-- If the filter contains a file path, make it relative to
 				-- this block's basedir
 				if abspath and block._basedir and block._basedir ~= basedir and not cset.compiled then
@@ -192,6 +208,7 @@
 					end
 				end
 			end
+		end
 
 		filter.files = abspath
 		return result
@@ -283,6 +300,7 @@
 
 		local block = {}
 		block._criteria = crit
+		block._origin = cset
 
 		if basedir then
 			block._basedir = basedir:lower()
@@ -309,6 +327,7 @@
 		local block = {}
 		block._criteria = filter._criteria
 		block._basedir = filter._basedir
+		block._origin = cset
 		table.insert(cset.blocks, block)
 		cset.current = block;
 	end
@@ -373,6 +392,7 @@
 		local block = {}
 		block._basedir = cset.current._basedir
 		block._criteria = cset.current._criteria
+		block._origin = cset
 		table.insert(cset.blocks, block)
 		cset.current = block
 
@@ -447,6 +467,9 @@
 
 		for i = 1, n do
 			local block = blocks[i]
+			if block._origin == cset then
+				block._origin = result
+			end
 
 			-- If the filter contains a file path, make it relative to
 			-- this block's basedir

src/base/context.lua

@@ -168,26 +168,35 @@
 --    The context to query.
 -- @param key
 --    The property key to query.
+-- @param onlylocal
+--     If true, don't combine values from parent contexts.
 -- @return
 --    The value of the key, as determined by the configuration set.  If
 --    there is a corresponding Premake field, and it the field is enabled
 --    for tokens, any contained tokens will be expanded.
 --
 
-	function context.fetchvalue(ctx, key)
+	function context.fetchvalue(ctx, key, onlylocal)
+		if not onlylocal then
+			local value = rawget(ctx, key)
+			if value ~= nil then
+				return value
+			end
+		end
+
 		-- The underlying configuration set will only hold registered fields.
 		-- If the requested key doesn't have a corresponding field, it is just
 		-- a regular value to be stored and fetched from the table.
 
 		local field = p.field.get(key)
 		if not field then
-			return rawget(ctx, key)
+			return nil
 		end
 
 		-- If there is a matching field, then go fetch the aggregated value
 		-- from my configuration set, and then cache it future lookups.
 
-		local value = configset.fetch(ctx._cfgset, field, ctx.terms, ctx)
+		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