tock-mirror/fco2/Unnest.hs
2007-04-12 16:55:26 +00:00

217 lines
8.1 KiB
Haskell

-- | Flatten nested declarations.
module Unnest (unnest) where
import Control.Monad.State
import Data.Generics
import qualified Data.Map as Map
import Data.Maybe
import qualified AST as A
import Metadata
import ParseState
import Types
import Pass
unnest :: A.Process -> PassM A.Process
unnest p = parsToProcs p >>= removeFreeNames >>= removeNesting
-- | Wrap the subprocesses of PARs in no-arg PROCs.
parsToProcs :: Data t => t -> PassM t
parsToProcs = doGeneric `extM` doProcess
where
doGeneric :: Data t => t -> PassM t
doGeneric = gmapM parsToProcs
doProcess :: A.Process -> PassM A.Process
doProcess (A.Par m pm ps)
= do ps' <- mapM parsToProcs ps
procs <- mapM (makeNonceProc m) ps'
let calls = [A.ProcSpec m s (A.ProcCall m n []) | s@(n, _) <- procs]
return $ A.Par m pm calls
doProcess (A.ParRep m pm rep p)
= do p' <- parsToProcs p
rep' <- parsToProcs rep
s@(n, _) <- makeNonceProc m p'
let call = A.ProcSpec m s (A.ProcCall m n [])
return $ A.ParRep m pm rep' call
doProcess p = doGeneric p
type NameMap = Map.Map String A.Name
-- | Get the set of free names within a block of code.
freeNamesIn :: Data t => t -> NameMap
freeNamesIn = doGeneric `extQ` doName `extQ` doProcess `extQ` doStructured `extQ` doValueProcess `extQ` doSpecType
where
doGeneric :: Data t => t -> NameMap
doGeneric n = Map.unions $ gmapQ freeNamesIn n
-- FIXME This won't do the right thing with tags.
doName :: A.Name -> NameMap
doName n = Map.singleton (A.nameName n) n
doProcess :: A.Process -> NameMap
doProcess (A.ProcSpec _ spec p) = doSpec spec p
doProcess (A.SeqRep _ rep p) = doRep rep p
doProcess (A.ParRep _ _ rep p) = doRep rep p
doProcess p = doGeneric p
doStructured :: A.Structured -> NameMap
doStructured (A.Rep _ rep s) = doRep rep s
doStructured (A.Spec _ spec s) = doSpec spec s
doStructured s = doGeneric s
doValueProcess :: A.ValueProcess -> NameMap
doValueProcess (A.ValOfSpec _ spec vp) = doSpec spec vp
doValueProcess vp = doGeneric vp
doSpec :: Data t => A.Specification -> t -> NameMap
doSpec (n, st) child
= Map.union fns $ Map.delete (A.nameName n) $ freeNamesIn child
where
fns = freeNamesIn st
doRep :: Data t => A.Replicator -> t -> NameMap
doRep rep child
= Map.union fns $ Map.delete (A.nameName repName) $ freeNamesIn child
where
(repName, fns) = case rep of
A.For _ n b c -> (n, Map.union (freeNamesIn b) (freeNamesIn c))
doSpecType :: A.SpecType -> NameMap
doSpecType (A.Proc _ fs p) = Map.difference (freeNamesIn p) (freeNamesIn fs)
doSpecType (A.Function _ _ fs vp) = Map.difference (freeNamesIn vp) (freeNamesIn fs)
doSpecType st = doGeneric st
-- | Replace names.
replaceNames :: Data t => [(A.Name, A.Name)] -> t -> t
replaceNames map p = everywhere (mkT $ doName) p
where
smap = [(A.nameName f, t) | (f, t) <- map]
doName :: A.Name -> A.Name
doName n
= case lookup (A.nameName n) smap of
Just n' -> n'
Nothing -> n
-- | Turn free names in PROCs into arguments.
removeFreeNames :: Data t => t -> PassM t
removeFreeNames = doGeneric `extM` doProcess `extM` doStructured `extM` doValueProcess
where
doGeneric :: Data t => t -> PassM t
doGeneric = gmapM removeFreeNames
doProcess :: A.Process -> PassM A.Process
doProcess (A.ProcSpec m spec p)
= do (spec', p') <- doSpec m spec p
return $ A.ProcSpec m spec' p'
doProcess p = doGeneric p
doStructured :: A.Structured -> PassM A.Structured
doStructured (A.Spec m spec s)
= do (spec', s') <- doSpec m spec s
return $ A.Spec m spec' s'
doStructured s = doGeneric s
doValueProcess :: A.ValueProcess -> PassM A.ValueProcess
doValueProcess (A.ValOfSpec m spec vp)
= do (spec', vp') <- doSpec m spec vp
return $ A.ValOfSpec m spec' vp'
doValueProcess vp = doGeneric vp
addToCalls :: Data t => A.Name -> [A.Actual] -> t -> t
addToCalls matchN newAs = everywhere (mkT atcProc)
where
atcProc :: A.Process -> A.Process
atcProc p@(A.ProcCall m n as)
= if sameName n matchN then A.ProcCall m n (as ++ newAs) else p
atcProc p = p
doSpec :: Data t => Meta -> A.Specification -> t -> PassM (A.Specification, t)
doSpec m spec child = case spec of
(n, st@(A.Proc m fs p)) ->
do
-- Figure out the free names
let allFreeNames = Map.elems $ freeNamesIn st
let freeNames = [n | n <- allFreeNames,
case A.nameType n of
A.ChannelName -> True
A.VariableName -> True
_ -> False]
ps <- get
let types = [fromJust $ typeOfName ps n | n <- freeNames]
let ams = [case fromJust $ abbrevModeOfName ps n of
A.Original -> A.Abbrev
t -> t
| n <- freeNames]
-- Generate and define new names to replace them with
newNamesS <- sequence [makeNonce (A.nameName n) | n <- freeNames]
let newNames = [on { A.nameName = nn } | (on, nn) <- zip freeNames newNamesS]
sequence_ [let ond = fromJust $ psLookupName ps on
in modify $ psDefineName nn (ond { A.ndName = A.nameName nn,
A.ndAbbrevMode = am })
| (on, nn, am) <- zip3 freeNames newNames ams]
ps' <- get
-- Add formals for each of the free names
let newFs = [A.Formal am t n | (am, t, n) <- zip3 ams types newNames]
p' <- removeFreeNames $ replaceNames (zip freeNames newNames) p
let st' = A.Proc m (fs ++ newFs) p'
let spec' = (n, st')
-- Update the definition of the proc
let nameDef = fromJust $ psLookupName ps n
modify $ psDefineName n (nameDef { A.ndType = st' })
-- Add extra arguments to calls of this proc
let newAs = [case am of
A.Abbrev -> A.ActualVariable (A.Variable m n)
_ -> A.ActualExpression (A.ExprVariable m (A.Variable m n))
| (am, n) <- zip ams freeNames]
child' <- removeFreeNames (addToCalls n newAs child)
return (spec', child')
_ ->
do spec' <- removeFreeNames spec
child' <- removeFreeNames child
return (spec', child')
-- | Pull nested declarations to the top level.
removeNesting :: A.Process -> PassM A.Process
removeNesting p
= do p' <- pullSpecs p
applyPulled p'
where
pullSpecs :: Data t => t -> PassM t
pullSpecs = doGeneric `extM` doProcess `extM` doStructured `extM` doValueProcess
doGeneric :: Data t => t -> PassM t
doGeneric = gmapM pullSpecs
doProcess :: A.Process -> PassM A.Process
doProcess orig@(A.ProcSpec m spec p) = doSpec orig m spec p
doProcess p = doGeneric p
doStructured :: A.Structured -> PassM A.Structured
doStructured orig@(A.Spec m spec s) = doSpec orig m spec s
doStructured s = doGeneric s
doValueProcess :: A.ValueProcess -> PassM A.ValueProcess
doValueProcess orig@(A.ValOfSpec m spec vp) = doSpec orig m spec vp
doValueProcess vp = doGeneric vp
doSpec :: Data t => t -> Meta -> A.Specification -> t -> PassM t
doSpec orig m spec@(_, st) child
= if canPull st then
do spec' <- pullSpecs spec
addPulled $ A.ProcSpec m spec'
child' <- pullSpecs child
return child'
else doGeneric orig
canPull :: A.SpecType -> Bool
canPull (A.Proc _ _ _) = True
canPull (A.DataType _ _) = True
canPull (A.DataTypeRecord _ _ _) = True
canPull (A.Protocol _ _) = True
canPull (A.ProtocolCase _ _) = True
-- FIXME: Should pull up constant expressions too
canPull _ = False