Add NoReturnFromNonVoidError

1 files changed, 16 insertions, 5 deletions

diff --git a/Sil/Check.icl b/Sil/Check.icl
index fa93ac9..0784291 100644
--- a/Sil/Check.icl
+++ b/Sil/Check.icl
@@ -1,10 +1,11 @@
 implementation module Sil.Check
 
 import StdFile
-from StdFunc import flip
+from StdFunc import flip, o
 import StdList
 import StdOverloaded
 import StdString
+import StdTuple
 
 from Data.Func import $, mapSt, seqSt
 import Data.Maybe
@@ -26,14 +27,24 @@ checkProgram :: *(Maybe *File) Program -> *([CheckError], *Maybe *File)
 checkProgram err prog = checkFunction err (hd prog.p_funs) //appFst flatten $ mapSt (flip checkFunction) prog.p_funs err
 
 checkFunction :: *(Maybe *File) Function -> *([CheckError], *Maybe *File)
-checkFunction err f = checkErrors [checkReturnExpressionFromVoid] f err
+checkFunction err f = checkErrors [checkReturnAndVoid] f err
 where
-	checkReturnExpressionFromVoid :: Function -> Maybe CheckError
-	checkReturnExpressionFromVoid f = case f.f_type of
+	checkReturnAndVoid :: Function -> Maybe CheckError
+	checkReturnAndVoid f = case f.f_type of
 		TVoid -> case [st \\ st=:(Return (Just _)) <- allStatements f] of
 			[] -> Nothing
 			_  -> Just $ ReturnExpressionFromVoidError f.f_name
-		_     -> Nothing
+		_     -> if (sureToReturn f.f_code) Nothing (Just $ NoReturnFromNonVoidError f.f_name)
+
+	sureToReturn :: CodeBlock -> Bool
+	sureToReturn cb = case cb.cb_content of
+		[]  -> False
+		sts -> case last sts of
+			Return _       -> True
+			While _ cb`    -> sureToReturn cb`
+			If bs (Just e) -> all sureToReturn [e:map snd bs]
+			If bs Nothing  -> all (sureToReturn o snd) bs
+			_              -> False
 
 checkErrors :: [(a -> Maybe CheckError)] a *(Maybe *File) -> *([CheckError], *Maybe *File)
 checkErrors cks x err = seqSt error (catMaybes $ map (flip ($) x) cks) $ noErrors err