%
+% (c) The University of Glasgow 2006
% (c) The Univserity of Glasgow 1992-2004
%
the STG paper.
\begin{code}
+{-# OPTIONS -w #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and fix
+-- any warnings in the module. See
+-- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
+-- for details
+
module ClosureInfo (
- ClosureInfo, LambdaFormInfo, SMRep, -- all abstract
- StandardFormInfo,
+ ClosureInfo(..), LambdaFormInfo(..), -- would be abstract but
+ StandardFormInfo(..), -- mkCmmInfo looks inside
+ SMRep,
ArgDescr(..), Liveness(..),
C_SRT(..), needsSRT,
mkLFThunk, mkLFReEntrant, mkConLFInfo, mkSelectorLFInfo,
mkApLFInfo, mkLFImported, mkLFArgument, mkLFLetNoEscape,
- mkClosureInfo, mkConInfo,
+ mkClosureInfo, mkConInfo, maybeIsLFCon,
closureSize, closureNonHdrSize,
closureGoodStuffSize, closurePtrsSize,
slopSize,
closureName, infoTableLabelFromCI,
- closureLabelFromCI, closureSRT,
+ closureLabelFromCI,
closureLFInfo, isLFThunk,closureSMRep, closureUpdReqd,
closureNeedsUpdSpace, closureIsThunk,
closureSingleEntry, closureReEntrant, isConstrClosure_maybe,
closureFunInfo, isStandardFormThunk, isKnownFun,
+ funTag, funTagLFInfo, tagForArity,
enterIdLabel, enterLocalIdLabel, enterReturnPtLabel,
closureValDescr, closureTypeDescr, -- profiling
isStaticClosure,
- cafBlackHoleClosureInfo, seCafBlackHoleClosureInfo,
+ cafBlackHoleClosureInfo,
staticClosureNeedsLink,
) where
#include "../includes/MachDeps.h"
#include "HsVersions.h"
+--import CgUtils
import StgSyn
-import SMRep -- all of it
+import SMRep
import CLabel
-import Packages ( isDllName )
-import PackageConfig ( PackageId )
-import StaticFlags ( opt_SccProfilingOn, opt_OmitBlackHoling,
- opt_Parallel, opt_DoTickyProfiling )
-import Id ( Id, idType, idArity, idName )
-import DataCon ( DataCon, dataConTyCon, isNullaryRepDataCon, dataConName )
-import Name ( Name, nameUnique, getOccName, getOccString )
-import OccName ( occNameString )
-import Type ( isUnLiftedType, Type, repType, splitTyConApp_maybe )
-import TcType ( tcSplitSigmaTy )
-import TyCon ( isFunTyCon, isAbstractTyCon )
-import BasicTypes ( TopLevelFlag(..), isNotTopLevel, isTopLevel, ipNameName )
+import Packages
+import PackageConfig
+import StaticFlags
+import Id
+import IdInfo
+import DataCon
+import Name
+import OccName
+import Type
+import TypeRep
+import TcType
+import TyCon
+import BasicTypes
import FastString
import Outputable
import Constants
-
-import TypeRep -- TEMP
\end{code}
-- the constructor's info table), and they don't have an SRT.
| ConInfo {
closureCon :: !DataCon,
- closureSMRep :: !SMRep,
- closureDllCon :: !Bool -- is in a separate DLL
+ closureSMRep :: !SMRep
}
-- C_SRT is what StgSyn.SRT gets translated to...
data C_SRT = NoC_SRT
| C_SRT !CLabel !WordOff !StgHalfWord {-bitmap or escape-}
+ deriving (Eq)
needsSRT :: C_SRT -> Bool
needsSRT NoC_SRT = False
needsSRT (C_SRT _ _ _) = True
+
+instance Outputable C_SRT where
+ ppr (NoC_SRT) = ptext (sLit "_no_srt_")
+ ppr (C_SRT label off bitmap) = parens (ppr label <> comma <> ppr off <> comma <> text (show bitmap))
\end{code}
%************************************************************************
data ArgDescr
= ArgSpec -- Fits one of the standard patterns
- !Int -- RTS type identifier ARG_P, ARG_N, ...
+ !StgHalfWord -- RTS type identifier ARG_P, ARG_N, ...
| ArgGen -- General case
Liveness -- Details about the arguments
(might_be_a_function thunk_ty)
might_be_a_function :: Type -> Bool
+-- Return False only if we are *sure* it's a data type
+-- Look through newtypes etc as much as poss
might_be_a_function ty
- | Just (tc,_) <- splitTyConApp_maybe (repType ty),
- not (isFunTyCon tc) && not (isAbstractTyCon tc) = False
- -- don't forget to check for abstract types, which might
- -- be functions too.
- | otherwise = True
+ = case splitTyConApp_maybe (repType ty) of
+ Just (tc, _) -> not (isDataTyCon tc)
+ Nothing -> True
\end{code}
@mkConLFInfo@ is similar, for constructors.
mkConLFInfo :: DataCon -> LambdaFormInfo
mkConLFInfo con = LFCon con
+maybeIsLFCon :: LambdaFormInfo -> Maybe DataCon
+maybeIsLFCon (LFCon con) = Just con
+maybeIsLFCon _ = Nothing
+
mkSelectorLFInfo id offset updatable
= LFThunk NotTopLevel False updatable (SelectorThunk offset)
(might_be_a_function (idType id))
name = idName id
sm_rep = chooseSMRep is_static lf_info tot_wds ptr_wds
-mkConInfo :: PackageId
- -> Bool -- Is static
+mkConInfo :: Bool -- Is static
-> DataCon
-> Int -> Int -- Total and pointer words
-> ClosureInfo
-mkConInfo this_pkg is_static data_con tot_wds ptr_wds
+mkConInfo is_static data_con tot_wds ptr_wds
= ConInfo { closureSMRep = sm_rep,
- closureCon = data_con,
- closureDllCon = isDllName this_pkg (dataConName data_con) }
+ closureCon = data_con }
where
sm_rep = chooseSMRep is_static (mkConLFInfo data_con) tot_wds ptr_wds
\end{code}
CLabel -- The code label
Int -- Its arity
-getCallMethod :: PackageId
- -> Name -- Function being applied
+getCallMethod :: Name -- Function being applied
+ -> CafInfo -- Can it refer to CAF's?
-> LambdaFormInfo -- Its info
-> Int -- Number of available arguments
-> CallMethod
-getCallMethod this_pkg name lf_info n_args
+getCallMethod name _ lf_info n_args
| nodeMustPointToIt lf_info && opt_Parallel
= -- If we're parallel, then we must always enter via node.
-- The reason is that the closure may have been
-- fetched since we allocated it.
EnterIt
-getCallMethod this_pkg name (LFReEntrant _ arity _ _) n_args
+getCallMethod name caf (LFReEntrant _ arity _ _) n_args
| n_args == 0 = ASSERT( arity /= 0 )
ReturnIt -- No args at all
| n_args < arity = SlowCall -- Not enough args
- | otherwise = DirectEntry (enterIdLabel this_pkg name) arity
+ | otherwise = DirectEntry (enterIdLabel name caf) arity
-getCallMethod this_pkg name (LFCon con) n_args
+getCallMethod name _ (LFCon con) n_args
= ASSERT( n_args == 0 )
ReturnCon con
-getCallMethod this_pkg name (LFThunk _ _ updatable std_form_info is_fun) n_args
- | is_fun -- Must always "call" a function-typed
- = SlowCall -- thing, cannot just enter it [in eval/apply, the entry code
+getCallMethod name caf (LFThunk _ _ updatable std_form_info is_fun) n_args
+ | is_fun -- it *might* be a function, so we must "call" it (which is
+ -- always safe)
+ = SlowCall -- We cannot just enter it [in eval/apply, the entry code
-- is the fast-entry code]
+ -- Since is_fun is False, we are *definitely* looking at a data value
| updatable || opt_DoTickyProfiling -- to catch double entry
{- OLD: || opt_SMP
I decided to remove this, because in SMP mode it doesn't matter
if we enter the same thunk multiple times, so the optimisation
of jumping directly to the entry code is still valid. --SDM
-}
- = ASSERT( n_args == 0 ) EnterIt
+ = EnterIt
+ -- We used to have ASSERT( n_args == 0 ), but actually it is
+ -- possible for the optimiser to generate
+ -- let bot :: Int = error Int "urk"
+ -- in (bot `cast` unsafeCoerce Int (Int -> Int)) 3
+ -- This happens as a result of the case-of-error transformation
+ -- So the right thing to do is just to enter the thing
| otherwise -- Jump direct to code for single-entry thunks
= ASSERT( n_args == 0 )
- JumpToIt (thunkEntryLabel this_pkg name std_form_info updatable)
+ JumpToIt (thunkEntryLabel name caf std_form_info updatable)
+
+getCallMethod name _ (LFUnknown True) n_args
+ = SlowCall -- Might be a function
-getCallMethod this_pkg name (LFUnknown True) n_args
- = SlowCall -- might be a function
+getCallMethod name _ (LFUnknown False) n_args
+ | n_args > 0
+ = WARN( True, ppr name <+> ppr n_args )
+ SlowCall -- Note [Unsafe coerce complications]
-getCallMethod this_pkg name (LFUnknown False) n_args
- = ASSERT2 ( n_args == 0, ppr name <+> ppr n_args )
- EnterIt -- Not a function
+ | otherwise
+ = EnterIt -- Not a function
-getCallMethod this_pkg name (LFBlackHole _) n_args
+getCallMethod name _ (LFBlackHole _) n_args
= SlowCall -- Presumably the black hole has by now
-- been updated, but we don't know with
-- what, so we slow call it
-getCallMethod this_pkg name (LFLetNoEscape 0) n_args
+getCallMethod name _ (LFLetNoEscape 0) n_args
= JumpToIt (enterReturnPtLabel (nameUnique name))
-getCallMethod this_pkg name (LFLetNoEscape arity) n_args
+getCallMethod name _ (LFLetNoEscape arity) n_args
| n_args == arity = DirectEntry (enterReturnPtLabel (nameUnique name)) arity
| otherwise = pprPanic "let-no-escape: " (ppr name <+> ppr arity)
isKnownFun _ = False
\end{code}
+Note [Unsafe coerce complications]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+In some (badly-optimised) DPH code we see this
+ Module X: rr :: Int = error Int "Urk"
+ Module Y: ...((X.rr |> g) True) ...
+ where g is an (unsafe) coercion of kind (Int ~ Bool->Bool), say
+
+It's badly optimised, because knowing that 'X.rr' is bottom, we should
+have dumped the application to True. But it should still work. These
+strange unsafe coercions arise from the case-of-error transformation:
+ (case (error Int "foo") of { ... }) True
+---> (error Int "foo" |> g) True
+
+Anyway, the net effect is that in STG-land, when casts are discarded,
+we *can* see a value of type Int applied to an argument. This only happens
+if (a) the programmer made a mistake, or (b) the value of type Int is
+actually bottom.
+
+So it's wrong to trigger an ASSERT failure in this circumstance. Instead
+we now emit a WARN -- mainly to draw attention to a probably-badly-optimised
+program fragment -- and do the conservative thing which is SlowCall.
+
+
-----------------------------------------------------------------------------
SRT-related stuff
isConstrClosure_maybe _ = Nothing
closureFunInfo :: ClosureInfo -> Maybe (Int, ArgDescr)
-closureFunInfo (ClosureInfo { closureLFInfo = LFReEntrant _ arity _ arg_desc})
- = Just (arity, arg_desc)
-closureFunInfo _
- = Nothing
+closureFunInfo (ClosureInfo { closureLFInfo = lf_info }) = lfFunInfo lf_info
+closureFunInfo _ = Nothing
+
+lfFunInfo :: LambdaFormInfo -> Maybe (Int, ArgDescr)
+lfFunInfo (LFReEntrant _ arity _ arg_desc) = Just (arity, arg_desc)
+lfFunInfo _ = Nothing
+
+funTag :: ClosureInfo -> Int
+funTag (ClosureInfo { closureLFInfo = lf_info }) = funTagLFInfo lf_info
+funTag _ = 0
+
+-- maybe this should do constructor tags too?
+funTagLFInfo :: LambdaFormInfo -> Int
+funTagLFInfo lf
+ -- A function is tagged with its arity
+ | Just (arity,_) <- lfFunInfo lf,
+ Just tag <- tagForArity arity
+ = tag
+
+ -- other closures (and unknown ones) are not tagged
+ | otherwise
+ = 0
+
+tagForArity :: Int -> Maybe Int
+tagForArity i | i <= mAX_PTR_TAG = Just i
+ | otherwise = Nothing
\end{code}
\begin{code}
Label generation.
\begin{code}
-infoTableLabelFromCI :: ClosureInfo -> CLabel
+infoTableLabelFromCI :: ClosureInfo -> CafInfo -> CLabel
infoTableLabelFromCI (ClosureInfo { closureName = name,
closureLFInfo = lf_info,
- closureSMRep = rep })
+ closureSMRep = rep }) caf
= case lf_info of
LFBlackHole info -> info
LFThunk _ _ upd_flag (ApThunk arity) _ ->
mkApInfoTableLabel upd_flag arity
- LFThunk{} -> mkLocalInfoTableLabel name
+ LFThunk{} -> mkLocalInfoTableLabel name caf
- LFReEntrant _ _ _ _ -> mkLocalInfoTableLabel name
+ LFReEntrant _ _ _ _ -> mkLocalInfoTableLabel name caf
other -> panic "infoTableLabelFromCI"
infoTableLabelFromCI (ConInfo { closureCon = con,
- closureSMRep = rep,
- closureDllCon = dll })
- | isStaticRep rep = mkStaticInfoTableLabel name dll
- | otherwise = mkConInfoTableLabel name dll
+ closureSMRep = rep }) caf
+ | isStaticRep rep = mkStaticInfoTableLabel name caf
+ | otherwise = mkConInfoTableLabel name caf
where
name = dataConName con
-- ClosureInfo for a closure (as opposed to a constructor) is always local
-closureLabelFromCI (ClosureInfo { closureName = nm }) = mkLocalClosureLabel nm
-closureLabelFromCI _ = panic "closureLabelFromCI"
+closureLabelFromCI (ClosureInfo { closureName = nm }) caf = mkLocalClosureLabel nm caf
+closureLabelFromCI _ _ = panic "closureLabelFromCI"
-- thunkEntryLabel is a local help function, not exported. It's used from both
-- entryLabelFromCI and getCallMethod.
-thunkEntryLabel this_pkg thunk_id (ApThunk arity) is_updatable
+thunkEntryLabel thunk_id _ (ApThunk arity) is_updatable
= enterApLabel is_updatable arity
-thunkEntryLabel this_pkg thunk_id (SelectorThunk offset) upd_flag
+thunkEntryLabel thunk_id _ (SelectorThunk offset) upd_flag
= enterSelectorLabel upd_flag offset
-thunkEntryLabel this_pkg thunk_id _ is_updatable
- = enterIdLabel this_pkg thunk_id
+thunkEntryLabel thunk_id caf _ is_updatable
+ = enterIdLabel thunk_id caf
enterApLabel is_updatable arity
| tablesNextToCode = mkApInfoTableLabel is_updatable arity
| tablesNextToCode = mkSelectorInfoLabel upd_flag offset
| otherwise = mkSelectorEntryLabel upd_flag offset
-enterIdLabel this_pkg id
- | tablesNextToCode = mkInfoTableLabel this_pkg id
- | otherwise = mkEntryLabel this_pkg id
+enterIdLabel id
+ | tablesNextToCode = mkInfoTableLabel id
+ | otherwise = mkEntryLabel id
enterLocalIdLabel id
| tablesNextToCode = mkLocalInfoTableLabel id
closureType = ty,
closureDescr = "" }
cafBlackHoleClosureInfo _ = panic "cafBlackHoleClosureInfo"
-
-seCafBlackHoleClosureInfo (ClosureInfo { closureName = nm,
- closureType = ty })
- = ClosureInfo { closureName = nm,
- closureLFInfo = LFBlackHole mkSECAFBlackHoleInfoTableLabel,
- closureSMRep = BlackHoleRep,
- closureSRT = NoC_SRT,
- closureType = ty,
- closureDescr = "" }
-seCafBlackHoleClosureInfo _ = panic "seCafBlackHoleClosureInfo"
\end{code}
%************************************************************************
AppTy fun _ -> getTyDescription fun
FunTy _ res -> '-' : '>' : fun_result res
TyConApp tycon _ -> getOccString tycon
- NoteTy (FTVNote _) ty -> getTyDescription ty
PredTy sty -> getPredTyDescription sty
ForAllTy _ ty -> getTyDescription ty
}
getPredTyDescription (ClassP cl tys) = getOccString cl
getPredTyDescription (IParam ip ty) = getOccString (ipNameName ip)
\end{code}
-
-
projects / ghc-hetmet.git / blobdiff