1 implementation module gen
7 from StdFunc import id, const
12 import qualified Data.Map as Map
19 import Control.Applicative
21 import Control.Monad.Trans
22 from Text import class Text(concat), instance Text String
29 :: Instr = Instr String [Arg] String
32 :: Arg = L Label | Lit Int | Raw String
33 :: SSMProgram :== [Instr]
34 :: GenError = Error String
35 :: Addressbook :== 'Map'.Map String Address
36 :: Address = LAB String Int | ADDR Int
37 :: Gen a :== RWST () SSMProgram (Addressbook, [Label]) (Either GenError) a
39 labelStream :: [Label]
40 labelStream = ["lbl_" +++ toString i\\i<-[1..]]
42 defaultAddressBook :: Addressbook
43 defaultAddressBook = extend "1printint" (LAB "1printint" 1)
44 $ extend "1printchar" (LAB "1printchar" 1)
45 $ extend "read" (LAB "read" 0)
46 $ extend "1readint" (LAB "1readint" 0)
47 $ extend "isEmpty" (LAB "isempty" 1)
50 gen :: AST -> Either String String
51 gen (AST fds) = case evalRWST prog () (defaultAddressBook, labelStream) of
52 Left (Error e) = Left e
53 Right (_, p) = Right $ toString p
56 Instr "bsr" [L "main"] "",
58 ] >>| tell programContext
61 programContext :: SSMProgram
62 programContext = [Lab "1printint"
63 ,Instr "link" [Lit 0] ""
64 ,Instr "ldl" [Lit -2] "load first argument"
65 ,Instr "trap" [Lit 0] "print int"
69 ,Instr "link" [Lit 0] ""
70 ,Instr "ldl" [Lit -2] "load first argument"
71 ,Instr "trap" [Lit 1] "print char"
75 ,Instr "link" [Lit 0] ""
76 ,Instr "trap" [Lit 10] "read int"
77 ,Instr "str" [Raw "RR"] ""
81 ,Instr "link" [Lit 0] ""
82 ,Instr "trap" [Lit 11] "read char"
83 ,Instr "str" [Raw "RR"] ""
87 ,Instr "link" [Lit 0] ""
88 ,Instr "ldl" [Lit -2] "load prt to list"
89 ,Instr "lda" [Lit 0] "derefrence ptr"
90 ,Instr "ldc" [Lit 0] ""
91 ,Instr "eq" [] "test for null pointer"
92 ,Instr "str" [Raw "RR"] ""
98 //helper functions for the gen monad
99 getAdressbook :: Gen Addressbook
100 getAdressbook = gets fst
102 updateAdressbook :: (Addressbook -> Addressbook) -> Gen Addressbook
103 updateAdressbook f = modify (appFst f) >>| getAdressbook
105 extend :: String Address Addressbook -> Addressbook
106 extend k pl g = 'Map'.put k pl g
109 fresh = gets snd >>= \vars->
110 modify (appSnd $ const $ tail vars) >>|
113 class g a :: a -> Gen ()
116 g UnNegation = tell [Instr "not" [] ""]
117 g UnMinus = tell [Instr "neg" [] ""]
120 g o = tell [Instr s [] ""]
136 BiCons = abort "Shit, Cons, how to deal with this?"
138 instance g FieldSelector where
139 g FieldFst = tell [Instr "lda" [Lit 0] "fst"]
140 g FieldSnd = tell [Instr "lda" [Lit 1] "snd"]
141 g FieldHd = tell [Instr "lda" [Lit -1] "hd"]
142 g FieldTl = tell [Instr "lda" [Lit 0] "tl"]
144 instance g Expr where
145 g (IntExpr _ i) = tell [Instr "ldc" [Lit i] ""]
146 g (CharExpr _ c) = tell [Instr "ldc" [Lit (toInt c)] ""]
147 g (BoolExpr _ b) = tell [Instr "ldc" [Lit (if b TRUE FALSE)] ""]
148 g (EmptyListExpr _) = tell [Instr "ldc" [Lit 0] ""]
149 >>| tell [Instr "sth" [] ""]
150 g (Op1Expr _ o e) = g e >>| g o
151 g (Op2Expr _ e1 BiCons e2) = g e2 >>| g e1
152 >>| tell [Instr "sth" [] ""]
153 >>| tell [Instr "ajs" [Lit -1] ""]
154 >>| tell [Instr "sth" [] ""]
155 g (Op2Expr _ e1 op e2) = g e1 >>| g e2 >>| g op
156 g (TupleExpr _ (e1,e2)) = g e1
157 >>| tell [Instr "sth" [] ""]
159 >>| tell [Instr "sth" [] ""]
160 >>| tell [Instr "ajs" [Lit -1] ""]
161 g (VarExpr _ (VarDef k fs)) = getAdressbook >>= \ab->case 'Map'.get k ab of
162 Just (ADDR t) = tell [Instr "ldl" [Lit t] ""] >>| mapM_ g fs >>| pure ()
163 _ = liftT (Left $ Error "Higher order functions not implemented")
164 g (FunExpr _ k es fs) = getAdressbook >>= \ab->case 'Map'.get k ab of
165 Just (LAB l arity) = if (arity <> (length es))
166 (liftT $ Left $ Error "Higher order functions not implemented")
169 >>| mapM_ (const $ tell [Instr "ajs" [Lit -1] ""]) es //clean up args
170 >>| tell [Instr "ldr" [Raw "RR"] ""])
171 _ = liftT (Left $ Error "Funcall to variable?")
173 jump :: String String -> Gen ()
174 jump instr k = getAdressbook >>= \ab->case 'Map'.get k ab of
175 Nothing = liftT (Left $ Error $ concat ["PANIC: ", k, " not found as function"])
176 Just (LAB t _) = tell [Instr instr [L t] (k +++"()")]
177 Just (ADDR t) = liftT (Left $ Error $ "PANIC: jump should go to label")
179 instance g Stmt where
180 g (IfStmt cond th el) =
181 fresh >>= \elseLabel->
182 fresh >>= \endLabel->
184 tell [Instr "brf" [L elseLabel] "branch else"] >>|
186 tell [Instr "bra" [L endLabel] "branch end if"] >>|
187 tell [Lab elseLabel] >>|
190 g (WhileStmt cond th) =
191 fresh >>= \startLabel->
192 fresh >>= \endLabel ->
193 tell [Lab startLabel] >>|
195 tell [Instr "brf" [L endLabel] "branch end while"] >>|
197 tell [Instr "bra" [L startLabel] "branch start while"] >>|
199 g (AssStmt (VarDef k fs) e) =
200 g e >>| getAdressbook >>= \ab->case 'Map'.get k ab of
201 Nothing = liftT (Left $ Error $ concat ["PANIC: ", k, " not found as var"])
202 Just (LAB t _) = liftT (Left $ Error $ "PANIC: cannot assign to function")
203 Just (ADDR t) = tell [Instr "stl" [Lit t] ""]
204 g (FunStmt k es fs) = mapM_ g es
206 >>| mapM_ (const $ tell [Instr "ajs" [Lit -1] ""]) es //clean up args
209 g (ReturnStmt Nothing) = tell [Instr "unlink" [] ""]
210 >>| tell [Instr "ret" [] ""]
211 g (ReturnStmt (Just e)) = g e
212 >>| tell [Instr "str" [Raw "RR"] ""]
213 >>| g (ReturnStmt Nothing)
215 foldVarDecl :: Int VarDecl -> Gen Int
216 foldVarDecl x (VarDecl _ _ k e) = g e
218 >>| updateAdressbook (extend k (ADDR x)) >>| pure (x + 1)
220 addVars :: [String] -> (Addressbook -> Addressbook)
222 addVars [x:xs] = \ab->extend x (ADDR (-2 - (length xs))) (addVars xs ab)
224 instance g FunDecl where
225 g (FunDecl _ k args _ vds stms) =
226 //varDecls can call the enclosing function, so first reserve a label for it
227 updateAdressbook (extend k (LAB k (length args))) >>|
228 getAdressbook >>= \oldMap ->
229 updateAdressbook (addVars args) >>|
231 tell [Instr "link" [Lit 0] ""] >>|
233 foldM foldVarDecl 1 vds >>|
236 updateAdressbook (const oldMap) >>| pure ()
238 annote :: Int String -> Gen ()
240 tell [Instr "annote" [Raw "MP", Lit pos, Lit pos, Raw "green", Raw key] ""]
242 class print a :: a -> [String]
244 instance print Instr where
245 print (Lab l) = [l, ":", "\n"]
246 print (Instr i args com) = ["\t", i] ++ print args ++ [" ;", com, "\n"]
248 instance print [Arg] where
249 print args = (map toString args)
251 instance toString Arg where
253 toString (Lit int) = toString int
256 instance toString SSMProgram where
257 toString p = concat $ intersperse " " $ map (\i-> concat $ intersperse " " $ print i) p