More fine grained recompile checking

commercialhaskell · Aug 19, 2015 · 4cbca17 · 4cbca17
1 parent e20ea86
commit 4cbca17
Showing 1 changed file with 11 additions and 8 deletions.
diff --git a/src/Stack/Build/ConstructPlan.hs b/src/Stack/Build/ConstructPlan.hs
@@ -445,7 +445,7 @@ checkDirtiness ps installed package present wanted = do
             case moldOpts of
                 Nothing -> Just "old configure information not found"
                 Just oldOpts
-                    | oldOpts /= wantConfigCache -> Just $ describeConfigDiff oldOpts wantConfigCache
+                    | Just reason <- describeConfigDiff oldOpts wantConfigCache -> Just reason
                     | psDirty ps -> Just "local file changes"
                     | otherwise -> Nothing
     case mreason of
@@ -454,19 +454,20 @@ checkDirtiness ps installed package present wanted = do
             tell mempty { wDirty = Map.singleton (packageName package) reason }
             return True
 
-describeConfigDiff :: ConfigCache -> ConfigCache -> Text
+describeConfigDiff :: ConfigCache -> ConfigCache -> Maybe Text
 describeConfigDiff old new
-    | configCacheDeps old /= configCacheDeps new = "dependencies changed"
-    | configCacheComponents old /= configCacheComponents new = "components changed"
-    | configCacheHaddock old && not (configCacheHaddock new) = "no longer building haddocks"
-    | not (configCacheHaddock old) && configCacheHaddock new = "building haddocks"
-    | oldOpts /= newOpts = T.pack $ concat
+    | configCacheDeps old /= configCacheDeps new = Just "dependencies changed"
+    | not $ Set.null newComponents =
+        Just $ "components added: " `T.append` T.intercalate ", "
+            (map (decodeUtf8With lenientDecode) (Set.toList newComponents))
+    | not (configCacheHaddock old) && configCacheHaddock new = Just "rebuilding with haddocks"
+    | oldOpts /= newOpts = Just $ T.pack $ concat
         [ "flags changed from "
         , show oldOpts
         , " to "
         , show newOpts
         ]
-    | otherwise = "unknown config cache difference"
+    | otherwise = Nothing
   where
     -- options set by stack
     isStackOpt t = any (`T.isPrefixOf` t)
@@ -487,6 +488,8 @@ describeConfigDiff old new
         | x == y = removeMatching xs ys
     removeMatching xs ys = (xs, ys)
 
+    newComponents = configCacheComponents new `Set.difference` configCacheComponents old
+
 psDirty :: PackageSource -> Bool
 psDirty (PSLocal lp) = lpDirtyFiles lp
 psDirty (PSUpstream _ _ _) = False -- files never change in an upstream package