constructor and method call using this

src/ByteCode/ClassFile.hs

@@ -42,6 +42,7 @@ data Operation = Opiadd
                | Opreturn
                | Opireturn
                | Opareturn
+               | Opinvokespecial Word16
                | Opgoto Word16
                | Opsipush Word16
                | Opldc_w Word16
@@ -108,6 +109,7 @@ opcodeEncodingLength Opaconst_null    = 1
 opcodeEncodingLength Opreturn               = 1
 opcodeEncodingLength Opireturn              = 1
 opcodeEncodingLength Opareturn              = 1
+opcodeEncodingLength (Opinvokespecial _)    = 3
 opcodeEncodingLength (Opgoto _)             = 3
 opcodeEncodingLength (Opsipush _)           = 3
 opcodeEncodingLength (Opldc_w _)            = 3
@@ -157,6 +159,7 @@ instance Serializable Operation where
     serialize Opreturn                  = [0xB1]
     serialize Opireturn                 = [0xAC]
     serialize Opareturn                 = [0xB0]
+    serialize (Opinvokespecial index)   = 0xB7 : unpackWord16 index
     serialize (Opgoto index)            = 0xA7 : unpackWord16 index
     serialize (Opsipush index)          = 0x11 : unpackWord16 index
     serialize (Opldc_w index)           = 0x13 : unpackWord16 index

src/ByteCode/ClassFile/Generator.hs

@@ -201,8 +201,17 @@ comparisonOperation CompareGreaterOrEqual branchLocation = Opif_icmpge branchLoc
 
 
 assembleMethod :: Assembler MethodDeclaration
-assembleMethod (MethodDeclaration _ _ _ (TypedStatement _ (Block statements))) (constants, ops) =
-    foldr assembleStatement (constants, ops) statements
+assembleMethod (MethodDeclaration _ name _ (TypedStatement _ (Block statements))) (constants, ops)
+    | name == "<init>" = let 
+            (constants_a, ops_a) = foldr assembleStatement (constants, ops) statements
+            init_ops = [Opaload 0, Opinvokespecial 2]
+        in
+            (constants_a, init_ops ++ ops_a)
+    | otherwise = let
+            (constants_a, ops_a) = foldr assembleStatement (constants, ops) statements
+            init_ops = [Opaload 0]
+        in
+            (constants_a, init_ops ++ ops_a)
 assembleMethod (MethodDeclaration _ _ _ stmt) (_, _) = error ("Block expected for method body, got: " ++ show stmt)
 
 assembleStatement :: Assembler Statement
@@ -223,9 +232,8 @@ assembleExpression (TypedExpression _ (BinaryOperation op a b)) (constants, ops)
     | elem op [CompareEqual, CompareNotEqual, CompareLessThan, CompareLessOrEqual, CompareGreaterThan, CompareGreaterOrEqual] = let
             (aConstants, aOps) = assembleExpression a (constants, ops)
             (bConstants, bOps) = assembleExpression b (aConstants, aOps)
-            current_offset = sum (map opcodeEncodingLength bOps)
-            cmp_op = comparisonOperation op (fromIntegral (current_offset + 10))
-            cmp_ops = [cmp_op, Opsipush 1, Opgoto (fromIntegral (current_offset + 13)), Opsipush 0]
+            cmp_op = comparisonOperation op 9
+            cmp_ops = [cmp_op, Opsipush 0, Opgoto 6, Opsipush 1]
         in
             (bConstants, bOps ++ cmp_ops)
 assembleExpression (TypedExpression _ (CharacterLiteral literal)) (constants, ops) = 

src/Main.hs

@@ -9,7 +9,7 @@ import ByteCode.ClassFile
 import Data.ByteString (pack, writeFile)
 
 main = do
-    let untypedAST = parse $ alexScanTokens "class Testklasse {void something(){return;}}"
+    let untypedAST = parse $ alexScanTokens "class Testklasse {Testklasse(){} boolean something(){return 5 + 8 - 12 * 22 > 9 - 2 + 3;}}"
     let typedAST = head (typeCheckCompilationUnit untypedAST)
     let abstractClassFile = classBuilder typedAST emptyClassFile
     let assembledClassFile = pack (serialize abstractClassFile)

src/Typecheck.hs

@@ -302,7 +302,7 @@ typeCheckStatement (Return expr) symtab classes =
         Nothing -> Nothing
    in case expr' of
         Just e' -> TypedStatement (getTypeFromExpr e') (Return (Just e'))
-        Nothing -> TypedStatement "Void" (Return Nothing)
+        Nothing -> TypedStatement "void" (Return Nothing)
 
 typeCheckStatement (StatementExpressionStatement stmtExpr) symtab classes =
   let stmtExpr' = typeCheckStatementExpression stmtExpr symtab classes