Basic function calling and generation

diff --git a/examples/codeGen.spl b/examples/codeGen.spl
index a9b650d..1f8cbfd 100644 (file)
--- a/examples/codeGen.spl
+++ b/examples/codeGen.spl
@@ -1,6 +1,4 @@
 main() {
-    var x = 4;
-    var y = 2;
-    var z = x + y;
-    return z;
+    var x = 3;
+    return 4 + 2 + x;
 }
\ No newline at end of file

diff --git a/gen.icl b/gen.icl
index e87542c..9145ee5 100644 (file)
--- a/gen.icl
+++ b/gen.icl
@@ -44,21 +44,28 @@ FALSE :== 0
 :: Gen a :== RWST Label SSMProgram (GenMap, [Label]) (Either GenError) a
 
 labelStream :: [Label]
-labelStream = map (\i-> concat ["lab_", toString i]) [1..]
+labelStream = map (\i-> concat ["lbl_", toString i]) [1..]
 
 gen :: AST -> String
-gen _ = prog
+gen (AST fds) = case evalRWST prog "" ('Map'.newMap, labelStream) of
+            Left (Error e) = e
+            Right (_, p) = toString p
     where
-        expr = (Op2Expr zero (Op1Expr zero UnMinus (IntExpr zero 4)) BiPlus (IntExpr zero 7))
-        expr2 = (FunExpr zero "test" [IntExpr zero 4] [])
-        stmt = (IfStmt (BoolExpr zero True) [] [])
-        prog = case evalRWST (g stmt) "end" ('Map'.newMap, labelStream) of
-            Left (Error e) = abort e
-            Right (_, prog) = toString prog
+        prog = tell [Instr "bra" [L "main"] ""] >>| mapM_ g fds
+//gen _ = prog
+//    where
+//        expr = (Op2Expr zero (Op1Expr zero UnMinus (IntExpr zero 4)) BiPlus (IntExpr zero 7))
+//        expr2 = (FunExpr zero "test" [IntExpr zero 4] [])
+//        stmt = (IfStmt (BoolExpr zero True) [] [])
+//        prog = case evalRWST (g stmt) 0 ('Map'.newMap, labelStream) of
+//            Left (Error e) = abort e
+//            Right (_, prog) = toString prog
 //gen _ = toString    [Lab "Test"
 //                    ,Instr "ldc" [Lit 1] "Eerste instructie"
 //                    ,Instr "ldc" [Lit 2] "Tweede instructie"]
 
+//TODO:
+//For now in the generation we assume all vars fit on the stack...
 
 //helper functions for the gen monad
 genMap :: Gen GenMap
@@ -79,7 +86,7 @@ class g a :: a -> Gen ()
 instance g Expr where
     g (VarExpr _ (VarDef k fs)) = load k >>= \instr-> tell [instr] //note: pure is pure for list, i.e. []
     g (IntExpr _ i) = loadP (LDC i) >>= \instr-> tell [instr]
-    g (CharExpr _ c) = undef //how to deal with strings?
+    g (CharExpr _ c) = abort "How to deal with chars?"
     g (BoolExpr _ True) = loadP (LDC TRUE) >>= \instr-> tell [instr]
     g (BoolExpr _ False) = loadP (LDC FALSE) >>= \instr-> tell [instr]
     g (Op2Expr _ e1 op e2) = g e1 >>| g e2 >>| tell [Instr (op2ins op) [] ""]
@@ -87,7 +94,11 @@ instance g Expr where
     g (Op1Expr _ UnMinus e) = g e >>| tell [Instr "neg" [] ""]
     g (EmptyListExpr _) = abort "Shit, empty list expr"
     g (TupleExpr p (e1,e2)) = abort "How to deal with tuples?"
-    g (FunExpr _ k es fs) = mapM g es >>| jump "bsr" k >>= \instr-> tell [instr]
+    g (FunExpr _ k es fs) = 
+        mapM g es >>| //put all arguments on the stack (todo: fix argument handling!)
+        jump "bsr" k >>= \instr-> 
+        tell [instr] >>| //actually branch to function
+        tell [Instr "ldr" [Raw "RR"] ""] //push return value on stack, todo: check for VOID
 
 instance g Stmt where
     g (IfStmt cond th el) = 
@@ -121,20 +132,28 @@ instance g Stmt where
         g (ReturnStmt Nothing)
 
 instance g VarDecl where
-    g _ = abort "How will we store vars? use the locals thing?"
-
-instance g FunDecl where
-    g (FunDecl _ k args mt vds stms) = 
-        fresh >>= \l-> let lbl = l+++"_"+++k in 
+    g (VarDecl _ Nothing _ _) = liftT (Left $ Error "PANIC: untyped vardecl")
+    g (VarDecl _ (Just t) k e) = 
+        (\l->k+++"_"+++l) <$> fresh >>= \lbl->
+        changeGenMap (extend k (FUNC lbl)) >>|
         tell [Lab lbl] >>|
-        changeGenMap (extend k (FUNC lbl)) >>| 
-        tell [Instr "link" [Lit $ length vds] ""] //reserve room for local variables
-        //Todo: actual code generation. Probably using 'RWST'.local to scope 
-        //the VarDecl in this function
-
-
+        g e >>| 
+        tell [Instr "str" [Raw "RR"] ""] >>|
+        tell [Instr "ret" [] ""]
 
 
+instance g FunDecl where
+    g (FunDecl _ k _ _ vds stms) = 
+        //varDecls can call the enclosing function, so first reserve a label for it 
+        (\l-> if (k=="main") "main" (l+++"_"+++k)) <$> fresh >>= \lbl->
+        changeGenMap (extend k (FUNC lbl)) >>|
+        //then generate functions for the VarDecls
+        genMap >>= \oldMap ->
+        mapM_ g vds  >>|
+        //then the main function 
+        tell [Lab lbl] >>|
+        mapM_ g stms >>|
+        changeGenMap (const oldMap) >>| pure ()
 
 op2ins :: Op2 -> String
 op2ins op = case op of
@@ -190,6 +209,7 @@ instance print [Arg] where
 instance toString Arg where
     toString (L l) = l
     toString (Lit int) = toString int
+    toString (Raw s) = s
 
 instance toString SSMProgram where
     toString p = concat $ intersperse " " $ map (\i-> concat $ intersperse " " $ print i) p
\ No newline at end of file