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 "1readchar" (LAB "1readchar" 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"] ""
97 //helper functions for the gen monad
98 getAdressbook :: Gen Addressbook
99 getAdressbook = gets fst
101 updateAdressbook :: (Addressbook -> Addressbook) -> Gen Addressbook
102 updateAdressbook f = modify (appFst f) >>| getAdressbook
104 extend :: String Address Addressbook -> Addressbook
105 extend k pl g = 'Map'.put k pl g
108 fresh = gets snd >>= \vars->
109 modify (appSnd $ const $ tail vars) >>|
112 class g a :: a -> Gen ()
115 g UnNegation = tell [Instr "not" [] ""]
116 g UnMinus = tell [Instr "neg" [] ""]
119 g o = tell [Instr s [] ""]
135 BiCons = abort "Shit, Cons, how to deal with this?"
137 instance g FieldSelector where
138 g FieldFst = tell [Instr "lda" [Lit 0] "fst"]
139 g FieldSnd = tell [Instr "lda" [Lit 1] "snd"]
140 g FieldHd = tell [Instr "lda" [Lit -1] "hd"]
141 g FieldTl = tell [Instr "lda" [Lit 0] "tl"]
143 instance g Expr where
144 g (IntExpr _ i) = tell [Instr "ldc" [Lit i] ""]
145 g (CharExpr _ c) = tell [Instr "ldc" [Lit (toInt c)] ""]
146 g (BoolExpr _ b) = tell [Instr "ldc" [Lit (if b TRUE FALSE)] ""]
147 g (EmptyListExpr _) = tell [Instr "ldc" [Lit 0] ""]
148 >>| tell [Instr "sth" [] ""]
149 g (Op1Expr _ o e) = g e >>| g o
150 g (Op2Expr _ e1 BiCons e2) = g e2 >>| g e1
151 >>| tell [Instr "sth" [] ""]
152 >>| tell [Instr "ajs" [Lit -1] ""]
153 >>| tell [Instr "sth" [] ""]
154 g (Op2Expr _ e1 op e2) = g e1 >>| g e2 >>| g op
155 g (TupleExpr _ (e1,e2)) = g e1
156 >>| tell [Instr "sth" [] ""]
158 >>| tell [Instr "sth" [] ""]
159 >>| tell [Instr "ajs" [Lit -1] ""]
160 g (VarExpr _ (VarDef k fs)) = getAdressbook >>= \ab->case 'Map'.get k ab of
161 Just (ADDR t) = tell [Instr "ldl" [Lit t] ""] >>| mapM_ g fs >>| pure ()
162 _ = liftT (Left $ Error "PANIC: variable and function name clash")
163 g (FunExpr _ k es fs) =
166 >>| mapM_ (const $ tell [Instr "ajs" [Lit -1] ""]) es //clean up args
167 >>| tell [Instr "ldr" [Raw "RR"] ""]
169 jump :: String String -> Gen ()
170 jump instr k = getAdressbook >>= \ab->case 'Map'.get k ab of
171 Nothing = liftT (Left $ Error $ concat ["PANIC: ", k, " not found as function"])
172 Just (LAB t _) = tell [Instr instr [L t] (k +++"()")]
173 Just (ADDR t) = liftT (Left $ Error $ "PANIC: jump should go to label")
175 instance g Stmt where
176 g (IfStmt cond th el) =
177 fresh >>= \elseLabel->
178 fresh >>= \endLabel->
180 tell [Instr "brf" [L elseLabel] "branch else"] >>|
182 tell [Instr "bra" [L endLabel] "branch end if"] >>|
183 tell [Lab elseLabel] >>|
186 g (WhileStmt cond th) =
187 fresh >>= \startLabel->
188 fresh >>= \endLabel ->
189 tell [Lab startLabel] >>|
191 tell [Instr "brf" [L endLabel] "branch end while"] >>|
193 tell [Instr "bra" [L startLabel] "branch start while"] >>|
195 g (AssStmt (VarDef k fs) e) =
196 g e >>| getAdressbook >>= \ab->case 'Map'.get k ab of
197 Nothing = liftT (Left $ Error $ concat ["PANIC: ", k, " not found as var"])
198 Just (LAB t _) = liftT (Left $ Error $ "PANIC: cannot assign to function")
199 Just (ADDR t) = tell [Instr "stl" [Lit t] ""]
200 g (FunStmt k es fs) = mapM_ g es
202 >>| mapM_ (const $ tell [Instr "ajs" [Lit -1] ""]) es //clean up args
205 g (ReturnStmt Nothing) = tell [Instr "unlink" [] ""]
206 >>| tell [Instr "ret" [] ""]
207 g (ReturnStmt (Just e)) = g e
208 >>| tell [Instr "str" [Raw "RR"] ""]
209 >>| g (ReturnStmt Nothing)
211 foldVarDecl :: Int VarDecl -> Gen Int
212 foldVarDecl x (VarDecl _ _ k e) = g e
214 >>| updateAdressbook (extend k (ADDR x)) >>| pure (x + 1)
216 addVars :: [String] -> (Addressbook -> Addressbook)
218 addVars [x:xs] = \ab->extend x (ADDR (-2 - (length xs))) (addVars xs ab)
220 instance g FunDecl where
221 g (FunDecl _ k args _ vds stms) =
222 //varDecls can call the enclosing function, so first reserve a label for it
223 updateAdressbook (extend k (LAB k (length args))) >>|
224 getAdressbook >>= \oldMap ->
225 updateAdressbook (addVars args) >>|
227 tell [Instr "link" [Lit 0] ""] >>|
229 foldM foldVarDecl 1 vds >>|
232 updateAdressbook (const oldMap) >>| pure ()
234 annote :: Int String -> Gen ()
236 tell [Instr "annote" [Raw "MP", Lit pos, Lit pos, Raw "green", Raw key] ""]
238 class print a :: a -> [String]
240 instance print Instr where
241 print (Lab l) = [l, ":", "\n"]
242 print (Instr i args com) = ["\t", i] ++ print args ++ [" ;", com, "\n"]
244 instance print [Arg] where
245 print args = (map toString args)
247 instance toString Arg where
249 toString (Lit int) = toString int
252 instance toString SSMProgram where
253 toString p = concat $ intersperse " " $ map (\i-> concat $ intersperse " " $ print i) p