Bugfix: else assembly

Test/TestParser.hs

@@ -145,6 +145,13 @@ testExpressionPreDecrement = TestCase $
     assertEqual "expect PreIncrement" (UnaryOperation PreDecrement (Reference "a")) $
     parseExpression [DECREMENT,IDENTIFIER "a"]
 
+testStatementIfThen = TestCase $
+    assertEqual "expect empty ifthen" [If (Reference "a") (Block [Block []]) Nothing] $
+    parseStatement [IF,LBRACE,IDENTIFIER "a",RBRACE,LBRACKET,RBRACKET]
+testStatementIfThenElse = TestCase $
+    assertEqual "expect empty ifthen" [If (Reference "a") (Block [Block []]) (Just (Block [Block []]))] $
+    parseStatement [IF,LBRACE,IDENTIFIER "a",RBRACE,LBRACKET,RBRACKET,ELSE,LBRACKET,RBRACKET]
+
 
 tests = TestList [
     testSingleEmptyClass,
@@ -185,5 +192,7 @@ tests = TestList [
     testExpressionPostIncrement,
     testExpressionPostDecrement,
     testExpressionPreIncrement,
-    testExpressionPreDecrement
+    testExpressionPreDecrement,
+    testStatementIfThen,
+    testStatementIfThenElse
     ]

src/ByteCode/ClassFile/Generator.hs

@@ -231,7 +231,8 @@ assembleStatement (constants, ops) (TypedStatement _ (If expr if_stmt else_stmt)
             Just stmt -> assembleStatement (constants_ifa, []) stmt
         -- +6 because we insert 2 gotos, one for if, one for else
         if_length = sum (map opcodeEncodingLength ops_ifa) + 6
-        else_length = sum (map opcodeEncodingLength ops_ifa)
+        -- +3 because we need to account for the goto in the if statement.
+        else_length = sum (map opcodeEncodingLength ops_elsea) + 3
     in
         (constants_ifa, ops ++ ops_cmp ++ [Opsipush 0, Opif_icmpeq if_length] ++ ops_ifa ++ [Opgoto else_length] ++ ops_elsea)
 assembleStatement stmt _ = error ("Not yet implemented: " ++ show stmt)

src/Parser/JavaParser.y

@@ -202,7 +202,7 @@ localvariabledeclarationstatement : localvariabledeclaration  SEMICOLON  { $1 }
 
 statement        : statementwithouttrailingsubstatement{ $1 }  -- statement returns a list of statements
                  | ifthenstatement { [$1] }
-                --  | ifthenelsestatement { }
+                 | ifthenelsestatement { [$1] }
                 --  | whilestatement { }
                                      
 
@@ -220,7 +220,7 @@ statementwithouttrailingsubstatement : block { [$1] }
 
 ifthenstatement  : IF LBRACE expression  RBRACE  statement { If $3 (Block $5) Nothing }
 
-ifthenelsestatement : IF LBRACE expression  RBRACE statementnoshortif ELSE statement  { }
+ifthenelsestatement : IF LBRACE expression  RBRACE statementnoshortif ELSE statement { If $3 (Block $5)  (Just (Block $7)) }
 
 whilestatement   : WHILE LBRACE expression  RBRACE  statement { }
 
@@ -234,9 +234,9 @@ expressionstatement : statementexpression  SEMICOLON { }
 returnstatement  : RETURN  SEMICOLON  { Return Nothing }
                  | RETURN expression  SEMICOLON { Return $ Just $2 }
 
-statementnoshortif : statementwithouttrailingsubstatement { }
-                 | ifthenelsestatementnoshortif { }
-                 | whilestatementnoshortif { }
+statementnoshortif : statementwithouttrailingsubstatement { $1 }
+                --  | ifthenelsestatementnoshortif { }
+                --  | whilestatementnoshortif { }
 
 conditionalexpression : conditionalorexpression { $1 }
                 --  | conditionalorexpression QUESMARK expression  COLON  conditionalexpression { }
@@ -370,6 +370,9 @@ data Declarator = Declarator Identifier (Maybe Expression)
 convertDeclarator :: DataType -> Declarator -> VariableDeclaration
 convertDeclarator dataType (Declarator id assigment) = VariableDeclaration dataType id assigment
 
+data StatementWithoutSub =  Statement
+
+
 parseError :: ([Token], [String]) -> a
 parseError (errortoken, expected) = error ("parse error on token: " ++ show errortoken ++ "\nexpected one of:      " ++ show expected)