%
+% (c) The University of Glasgow 2006
% (c) The Univserity of Glasgow 1992-2004
%
#include "HsVersions.h"
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 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}
(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.
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
+ | is_fun -- *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 )