labelStream :: [Label]
labelStream = ["lbl_" +++ toString i\\i<-[1..]]
+defaultAddressBook :: Addressbook
+defaultAddressBook = extend "print" (LAB "print")
+ $ extend "read" (LAB "read")
+ $ extend "isEmpty" (LAB "isEmpty")
+ 'Map'.newMap
+
gen :: AST -> Either String String
-gen (AST fds) = case evalRWST prog () ('Map'.newMap, labelStream) of
+gen (AST fds) = case evalRWST prog () (defaultAddressBook, labelStream) of
Left (Error e) = Left e
Right (_, p) = Right $ toString p
where
prog = tell [
Instr "bsr" [L "main"] "",
Instr "halt" [] ""
- ] >>| mapM_ g fds
-
-//Current issues:
-//All VarDecls are added as function, how to deal with assignments?
-// (And when we deal with assignments, how to deal with assignments to higher order functions?)
-//Dealing with arguments
-//Dealing with types that do not fit on the Stack
-// Probably completely change LoadPlace to a Type and a position relative to *something*
-// And where the type determines if this position is a pointer to the heap or an
-// unboxed value
+ ] >>| tell programContext
+ >>| mapM_ g fds
+
+programContext :: SSMProgram
+programContext = [Lab "print" //there is no actual IO in SSM
+ ,Instr "link" [Lit 0] ""
+ ,Instr "unlink" [] ""
+ ,Instr "ret" [] ""
+ ,Lab "read" //there is no actual IO in SSM
+ ,Instr "link" [Lit 0] ""
+ ,Instr "ldc" [Lit 0] ""
+ ,Instr "sth" [] ""
+ ,Instr "str" [Raw "RR"] ""
+ ,Instr "unlink" [] ""
+ ,Instr "ret" [] ""
+ ,Lab "isEmpty"
+ ,Instr "link" [Lit 0] ""
+ ,Instr "ldl" [Lit -2] "load prt to list"
+ ,Instr "lda" [Lit 0] "derefrence ptr"
+ ,Instr "ldc" [Lit 0] ""
+ ,Instr "eq" [] "test for null pointer"
+ ,Instr "str" [Raw "RR"] ""
+ ,Instr "unlink" [] ""
+ ,Instr "ret" [] ""
+ ]
//helper functions for the gen monad
getAdressbook :: Gen Addressbook
Just (LAB t) = liftT (Left $ Error "PANIC: variable and function name clash")
//load k >>= \instr-> tell [instr] //note: pure is pure for list, i.e. []
g (FunExpr _ k es fs) =
-// tell [Instr "ldr" [Raw "MP"] ("old frame pointer")]
- mapM g es
+ mapM_ g es
>>| jump "bsr" k
+ >>| mapM_ (const $ tell [Instr "ajs" [Lit -1] ""]) es //clean up args
>>| tell [Instr "ldr" [Raw "RR"] ""]
jump :: String String -> Gen ()
Just (ADDR t) = liftT (Left $ Error $ "PANIC: jump should go to label")
instance g Stmt where
-// g (IfStmt cond th el) =
-// fresh >>= \elseLabel->
-// fresh >>= \endLabel->
-// g cond >>|
-// tell [Instr "brf" [L elseLabel] "branch else"] >>|
-// mapM_ g th >>|
-// tell [Instr "bra" [L endLabel] "branch end if"] >>|
-// tell [Lab elseLabel] >>|
-// mapM_ g el >>|
-// tell [Lab endLabel]
-// g (WhileStmt cond th) =
-// fresh >>= \startLabel->
-// fresh >>= \endLabel ->
-// tell [Lab startLabel] >>|
-// g cond >>|
-// tell [Instr "brf" [L endLabel] "branch end while"] >>|
-// mapM_ g th >>|
-// tell [Instr "bra" [L startLabel] "branch start while"] >>|
-// tell [Lab endLabel]
-// g (AssStmt (VarDef k fs) e) =
-// g e >>|
-// abort "Shit, an assignment, figure out something with storing vars or something"
-// //vars will be on stack in locals (possible pointers to heap)
-// g (FunStmt _ _) = abort "CodeGen, FunStmt unused" //not used
+ g (IfStmt cond th el) =
+ fresh >>= \elseLabel->
+ fresh >>= \endLabel->
+ g cond >>|
+ tell [Instr "brf" [L elseLabel] "branch else"] >>|
+ mapM_ g th >>|
+ tell [Instr "bra" [L endLabel] "branch end if"] >>|
+ tell [Lab elseLabel] >>|
+ mapM_ g el >>|
+ tell [Lab endLabel]
+ g (WhileStmt cond th) =
+ fresh >>= \startLabel->
+ fresh >>= \endLabel ->
+ tell [Lab startLabel] >>|
+ g cond >>|
+ tell [Instr "brf" [L endLabel] "branch end while"] >>|
+ mapM_ g th >>|
+ tell [Instr "bra" [L startLabel] "branch start while"] >>|
+ tell [Lab endLabel]
+ g (AssStmt (VarDef k fs) e) =
+ g e >>| getAdressbook >>= \ab->case 'Map'.get k ab of
+ Nothing = liftT (Left $ Error $ concat ["PANIC: ", k, " not found as var"])
+ Just (LAB t) = liftT (Left $ Error $ "PANIC: cannot assign to function")
+ Just (ADDR t) = tell [Instr "stl" [Lit t] ""]
+ g (FunStmt k es) = mapM_ g es
+ >>| jump "bsr" k
+ >>| mapM_ (const $ tell [Instr "ajs" [Lit -1] ""]) es //clean up args
+ >>| pure ()
g (ReturnStmt Nothing) = tell [Instr "unlink" [] ""]
>>| tell [Instr "ret" [] ""]
g (ReturnStmt (Just e)) = g e
foldVarDecl :: Int VarDecl -> Gen Int
foldVarDecl x (VarDecl _ _ k e) = g e
+ >>| annote x k
>>| updateAdressbook (extend k (ADDR x)) >>| pure (x + 1)
addVars :: [String] -> (Addressbook -> Addressbook)
updateAdressbook (addVars args) >>|
tell [Lab k] >>|
tell [Instr "link" [Lit 0] ""] >>|
- //then generate functions for the VarDecls
+ //add the vars
foldM foldVarDecl 1 vds >>|
- //then the main function
+ //and the statements
mapM_ g stms >>|
updateAdressbook (const oldMap) >>| pure ()
+annote :: Int String -> Gen ()
+annote pos key =
+ tell [Instr "annote" [Raw "MP", Lit pos, Lit pos, Raw "green", Raw key] ""]
+
class print a :: a -> [String]
instance print Instr where