{- Tock: a compiler for parallel languages Copyright (C) 2007, 2008 University of Kent This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . -} -- | A module containing all the misc Rain-specific passes that must be run on the parsed Rain AST before it can be fed into the shared passes. module RainPasses where import Control.Monad.State import Data.Generics import Data.List import qualified Data.Map as Map import Data.Maybe import qualified AST as A import CompState import Errors import Pass import qualified Properties as Prop import RainTypes import SimplifyTypes import Traversal import TreeUtils import Types -- | An ordered list of the Rain-specific passes to be run. rainPasses :: [Pass] rainPasses = let f = makePassesDep' ((== FrontendRain) . csFrontend) in f [ ("AST Validity check, Rain #1", excludeNonRainFeatures, [], []) -- TODO work out some dependencies ,("Dummy Rain pass", return, [], [Prop.retypesChecked]) ,("Resolve Int -> Int64", transformInt, [], [Prop.noInt]) ,("Uniquify variable declarations, record declared types and resolve variable names", uniquifyAndResolveVars, [Prop.noInt], Prop.agg_namesDone \\ [Prop.inferredTypesRecorded]) ,("Record inferred name types in dictionary", recordInfNameTypes, Prop.agg_namesDone \\ [Prop.inferredTypesRecorded], [Prop.inferredTypesRecorded]) ,("Rain Type Checking", performTypeUnification, [Prop.noInt] ++ Prop.agg_namesDone, [Prop.expressionTypesChecked, Prop.functionTypesChecked, Prop.processTypesChecked, Prop.retypesChecked]) ,("Fold all constant expressions", constantFoldPass, [Prop.noInt] ++ Prop.agg_namesDone ++ [Prop.inferredTypesRecorded], [Prop.constantsFolded, Prop.constantsChecked]) ] ++ enablePassesWhen ((== FrontendRain) . csFrontend) simplifyTypes ++ f [ ("Find and tag the main function", findMain, Prop.agg_namesDone, [Prop.mainTagged]) ,("Convert seqeach/pareach loops over ranges into simple replicated SEQ/PAR", transformEachRange, Prop.agg_typesDone ++ [Prop.constantsFolded], [Prop.eachRangeTransformed]) ,("Pull up foreach-expressions", pullUpForEach, Prop.agg_typesDone ++ [Prop.constantsFolded], [Prop.eachTransformed]) ,("Convert simple Rain range constructors into more general array constructors",transformRangeRep, Prop.agg_typesDone ++ [Prop.eachRangeTransformed], [Prop.rangeTransformed]) ,("Transform Rain functions into the occam form",checkFunction, Prop.agg_typesDone, []) --TODO add an export property. Maybe check other things too (lack of comms etc -- but that could be combined with occam?) ,("Pull up par declarations", pullUpParDeclarations, [], [Prop.rainParDeclarationsPulledUp]) ,("Mobilise lists", mobiliseLists, [], []) --TODO properties ,("Implicit mobility pass", implicitMobility, [], []) --TODO properties ] -- | A pass that transforms all instances of 'A.Int' into 'A.Int64' transformInt :: PassType transformInt = applyDepthM transformInt' where transformInt' :: A.Type -> PassM A.Type transformInt' A.Int = return A.Int64 transformInt' t = return t -- | This pass effectively does three things in one: -- -- 1. Creates unique names for all declared variables -- -- 2. Records the type of these declarations into the state -- -- 3. Resolves all uses of the name into its unique version -- -- This may seem like three passes in one, but if you try to separate them out, it just ends up -- with more confusion and more code. -- -- This pass works because everywhereM goes bottom-up, so declarations are --resolved from the bottom upwards. uniquifyAndResolveVars :: PassType uniquifyAndResolveVars = applyDepthSM uniquifyAndResolveVars' where uniquifyAndResolveVars' :: Data a => A.Structured a -> PassM (A.Structured a) --Variable declarations: uniquifyAndResolveVars' (A.Spec m (A.Specification m' n decl@(A.Declaration {})) scope) = do n' <- makeNonce $ A.nameName n defineName (n {A.nameName = n'}) A.NameDef {A.ndMeta = m', A.ndName = n', A.ndOrigName = A.nameName n, A.ndSpecType = decl, A.ndAbbrevMode = A.Original, A.ndPlacement = A.Unplaced} let scope' = everywhere (mkT $ replaceNameName (A.nameName n) n') scope return $ A.Spec m (A.Specification m' n {A.nameName = n'} decl) scope' --Processes: uniquifyAndResolveVars' (A.Spec m (A.Specification m' n (A.Proc m'' procMode params procBody)) scope) = do (params',procBody') <- doFormals params procBody let newProc = (A.Proc m'' procMode params' procBody') defineName n A.NameDef {A.ndMeta = m', A.ndName = A.nameName n, A.ndOrigName = A.nameName n, A.ndSpecType = newProc, A.ndAbbrevMode = A.Original, A.ndPlacement = A.Unplaced} return $ A.Spec m (A.Specification m' n newProc) scope -- Functions: uniquifyAndResolveVars' (A.Spec m (A.Specification m' n (A.Function m'' funcMode retTypes params funcBody)) scope) = do (params', funcBody') <- doFormals params funcBody let newFunc = (A.Function m'' funcMode retTypes params' funcBody') defineName n A.NameDef {A.ndMeta = m', A.ndName = A.nameName n, A.ndOrigName = A.nameName n, A.ndSpecType = newFunc, A.ndAbbrevMode = A.Original, A.ndPlacement = A.Unplaced} return $ A.Spec m (A.Specification m' n newFunc) scope -- replicator names have their types recorded later, but are -- uniquified and resolved here uniquifyAndResolveVars' (A.Rep m (A.ForEach m' n e) scope) = do n' <- makeNonce $ A.nameName n let scope' = everywhere (mkT $ replaceNameName (A.nameName n) n') scope return $ A.Rep m (A.ForEach m' (n {A.nameName = n'}) e) scope' --Other: uniquifyAndResolveVars' s = return s --This function is like applying mapM to doFormals', but we need to let each doFormals' call in turn --transform the scope of the formals. This could possibly be done by using a StateT monad with the scope, --but this method works just as well: doFormals :: Data t => [A.Formal] -> t -> PassM ([A.Formal],t) doFormals [] s = return ([],s) doFormals (f:fs) s = do (f',s') <- doFormals' f s (fs',s'') <- doFormals fs s' return ((f':fs'),s'') doFormals' :: Data t => A.Formal -> t -> PassM (A.Formal,t) doFormals' (A.Formal am t n) scope = do n' <- makeNonce $ A.nameName n let newName = (n {A.nameName = n'}) let m = A.nameMeta n defineName newName A.NameDef {A.ndMeta = m, A.ndName = n', A.ndOrigName = A.nameName n, A.ndSpecType = (A.Declaration m t), A.ndAbbrevMode = am, A.ndPlacement = A.Unplaced} let scope' = everywhere (mkT $ replaceNameName (A.nameName n) n') scope return (A.Formal am t newName, scope') -- | Helper function for a few of the passes. Replaces 'A.nameName' of a 'A.Name' if it matches a given 'String'. replaceNameName :: String -- ^ The variable name to be replaced. -> String -- ^ The new variable to use instead. -> A.Name -- ^ The name to check. -> A.Name -- ^ The new name, with the 'A.nameName' field replaced if it matched. replaceNameName find replace n = if (A.nameName n) == find then n {A.nameName = replace} else n -- | A pass that finds and tags the main process, and also mangles its name (to avoid problems in the C\/C++ backends with having a function called main). findMain :: PassType --Because findMain runs after uniquifyAndResolveVars, the types of all the process will have been recorded --Therefore this pass doesn't actually need to walk the tree, it just has to look for a process named "main" --in the CompState, and pull it out into csMainLocals findMain x = do newMainName <- makeNonce "main_" modify (findMain' newMainName) applyDepthM (return . (replaceNameName "main" newMainName)) x where --We have to mangle the main name because otherwise it will cause problems on some backends (including C and C++) findMain' :: String -> CompState -> CompState findMain' newn st = case Map.lookup "main" (csNames st) of Just n -> st { csNames = changeMainName newn (csNames st) , csMainLocals = makeMainLocals (findMeta n) newn } Nothing -> st changeMainName :: String -> Map.Map String A.NameDef -> Map.Map String A.NameDef changeMainName newn m = case Map.lookup "main" m of Just nd -> Map.insert newn (nd {A.ndName = newn}) $ Map.delete "main" m Nothing -> m -- The Rain parser doesn't set csMainLocals, so this pass constructs it -- from scratch. makeMainLocals :: Meta -> String -> [(String, (A.Name, NameType))] makeMainLocals m newn = [(newn, (A.Name m newn, ProcName))] checkIntegral :: A.LiteralRepr -> Maybe Integer checkIntegral (A.IntLiteral _ s) = Just $ read s checkIntegral (A.HexLiteral _ s) = Nothing -- TODO support hex literals checkIntegral (A.ByteLiteral _ s) = Nothing -- TODO support char literals checkIntegral _ = Nothing -- | Transforms seqeach\/pareach loops over things like [0..99] into SEQ i = 0 FOR 100 loops transformEachRange :: PassType transformEachRange = applyDepthSM doStructured where doStructured :: Data a => A.Structured a -> PassM (A.Structured a) doStructured (A.Rep repMeta (A.ForEach eachMeta loopVar (A.ExprConstr _ (A.RangeConstr _ _ begin end))) body) = do -- Need to change the stored abbreviation mode to original: modifyName loopVar $ \nd -> nd { A.ndAbbrevMode = A.Original } return $ A.Rep repMeta (A.For eachMeta loopVar begin (addOne $ subExprs end begin)) body doStructured s = return s -- | A pass that changes all the Rain range constructor expressions into the more general array constructor expressions -- -- TODO make sure when the range has a bad order that an empty list is -- returned transformRangeRep :: PassType transformRangeRep = applyDepthM doExpression where doExpression :: A.Expression -> PassM A.Expression doExpression (A.ExprConstr _ (A.RangeConstr m t begin end)) = do A.Specification _ rep _ <- makeNonceVariable "rep_constr" m A.Int A.ValAbbrev let count = addOne $ subExprs end begin return $ A.ExprConstr m $ A.RepConstr m t (A.For m rep begin count) (A.ExprVariable m $ A.Variable m rep) doExpression e = return e -- TODO this is almost certainly better figured out from the CFG checkFunction :: PassType checkFunction = return -- applyDepthM checkFunction' where checkFunction' :: A.Specification -> PassM A.Specification checkFunction' spec@(A.Specification _ n (A.Function m _ _ _ (Right body))) = case body of (A.Seq m' seqBody) -> let A.Several _ statements = skipSpecs seqBody in if (null statements) then dieP m "Functions must not have empty bodies" else case (last statements) of (A.Only _ (A.Assign _ [A.Variable _ dest] _)) -> if A.nameName n == A.nameName dest then return spec else dieP m "Functions must have a return statement as their last statement." _ -> dieP m "Functions must have a return statement as their last statement" _ -> dieP m $ "Functions must have seq[uential] bodies, found instead: " ++ showConstr (toConstr body) checkFunction' s = return s skipSpecs :: A.Structured A.Process -> A.Structured A.Process skipSpecs (A.Spec _ _ inner) = skipSpecs inner skipSpecs s = s -- | Pulls up the list expression into a variable. -- This is done no matter how simple the expression is; when we reach the -- backend we need it to be a variable so we can use begin() and end() (in -- C++); these will only be valid if exactly the same list is used -- throughout the loop. pullUpForEach :: PassType pullUpForEach = applyDepthSM doStructured where doStructured :: Data a => A.Structured a -> PassM (A.Structured a) doStructured (A.Rep m (A.ForEach m' loopVar loopExp) s) = do (extra, loopExp') <- case loopExp of A.ExprVariable {} -> return (id, loopExp) _ -> do t <- astTypeOf loopExp spec@(A.Specification _ n _) <- makeNonceIsExpr "loop_expr" m' t loopExp return (A.Spec m' spec, A.ExprVariable m' (A.Variable m' n)) return $ extra $ A.Rep m (A.ForEach m' loopVar loopExp') s doStructured s = return s pullUpParDeclarations :: PassType pullUpParDeclarations = applyDepthM pullUpParDeclarations' where pullUpParDeclarations' :: A.Process -> PassM A.Process pullUpParDeclarations' p@(A.Par m mode inside) = case chaseSpecs inside of Just (specs, innerCode) -> return $ A.Seq m $ specs $ A.Only m $ A.Par m mode innerCode Nothing -> return p pullUpParDeclarations' p = return p chaseSpecs :: A.Structured A.Process -> Maybe (A.Structured A.Process -> A.Structured A.Process, A.Structured A.Process) chaseSpecs (A.Spec m spec inner) = case chaseSpecs inner of Nothing -> Just (A.Spec m spec,inner) Just (trans,inner') -> Just ( (A.Spec m spec) . trans,inner') chaseSpecs _ = Nothing mobiliseLists :: PassType mobiliseLists x = (get >>= applyDepthM mobilise >>= put) >> applyDepthM mobilise x where mobilise :: A.Type -> PassM A.Type mobilise t@(A.List _) = return $ A.Mobile t mobilise t = return t -- | All the items that should not occur in an AST that comes from Rain (up until it goes into the shared passes). excludeNonRainFeatures :: (Data t, CSMR m) => t -> m t excludeNonRainFeatures = excludeConstr [ con0 A.Real32 ,con0 A.Real64 ,con2 A.Counted ,con1 A.Port ,con2 A.BytesInExpr ,con2 A.BytesInType ,con3 A.OffsetOf ,con0 A.After ,con3 A.InCounted ,con3 A.OutCounted ,con2 A.Place ,con3 A.IsChannelArray ,con4 A.Retypes ,con4 A.RetypesExpr ,con0 A.PriPar ,con0 A.PlacedPar ,con1 A.Stop ,con3 A.Processor ,con3 A.IntrinsicProcCall ]