type RttiInstantiation = [(TcTyVar, TyVar)]
-- Associates the typechecker-world meta type variables
-- (which are mutable and may be refined), to their
- -- debugger-world RuntimeUnkSkol counterparts.
+ -- debugger-world RuntimeUnk counterparts.
-- If the TcTyVar has not been refined by the runtime type
-- elaboration, then we want to turn it back into the
- -- original RuntimeUnkSkol
+ -- original RuntimeUnk
-- | Returns the instantiated type scheme ty', and the
-- mapping from new (instantiated) -to- old (skolem) type variables
zonk_unbound_meta tv
= ASSERT( isTcTyVar tv )
do { tv' <- skolemiseUnboundMetaTyVar tv RuntimeUnk
- -- This is where RuntimeUnkSkols are born:
+ -- This is where RuntimeUnks are born:
-- otherwise-unconstrained unification variables are
- -- turned into RuntimeUnkSkols as they leave the
+ -- turned into RuntimeUnks as they leave the
-- typechecker's monad
; return (mkTyVarTy tv') }
(anal_binds, anal_dus) -> return (valbind', valbind'_dus)
where
valbind' = ValBindsOut anal_binds sigs'
- valbind'_dus = usesOnly (hsSigsFVs sigs') `plusDU` anal_dus
+ valbind'_dus = anal_dus `plusDU` usesOnly (hsSigsFVs sigs')
+ -- Put the sig uses *after* the bindings
+ -- so that the binders are removed from
+ -- the uses in the sigs
}
rnValBindsRHS _ _ b = pprPanic "rnValBindsRHS" (ppr b)
| not (dopt Opt_D_dump_inlinings dflags) = stuff
| not (dopt Opt_D_verbose_core2core dflags)
= if isExternalName (idName var) then
- pprTrace "Inlining done:" (ppr var) stuff
+ pprDefiniteTrace "Inlining done:" (ppr var) stuff
else stuff
| otherwise
- = pprTrace ("Inlining done: " ++ showSDoc (ppr var))
+ = pprDefiniteTrace ("Inlining done: " ++ showSDoc (ppr var))
(vcat [text "Inlined fn: " <+> nest 2 (ppr unfolding),
text "Cont: " <+> ppr cont])
stuff
, not (dopt Opt_D_dump_rule_rewrites dflags) = stuff
| not (dopt Opt_D_dump_rule_rewrites dflags)
- = pprTrace "Rule fired:" (ftext (ru_name rule)) stuff
+ = pprDefiniteTrace "Rule fired:" (ftext (ru_name rule)) stuff
| otherwise
- = pprTrace "Rule fired"
+ = pprDefiniteTrace "Rule fired"
(vcat [text "Rule:" <+> ftext (ru_name rule),
text "Before:" <+> hang (ppr fn) 2 (sep (map pprParendExpr args)),
text "After: " <+> pprCoreExpr rule_rhs,
import TcSMonad
import TcType
import TypeRep
+import Type( isTyVarTy )
import Inst
import InstEnv
reportTyVarEqErr :: ReportErrCtxt -> TcTyVar -> TcType -> TcM ()
-- tv1 and ty2 are already tidied
reportTyVarEqErr ctxt tv1 ty2
- | not is_meta1
- , Just tv2 <- tcGetTyVar_maybe ty2
- , isMetaTyVar tv2
- = -- sk ~ alpha: swap
- reportTyVarEqErr ctxt tv2 ty1
-
- | (not is_meta1)
- = -- sk ~ ty, where ty isn't a meta-tyvar: mis-match
- addErrorReport (addExtraInfo ctxt ty1 ty2)
+ | isSkolemTyVar tv1 -- ty2 won't be a meta-tyvar, or else the thing would
+ -- be oriented the other way round; see TcCanonical.reOrient
+ || isSigTyVar tv1 && not (isTyVarTy ty2)
+ = addErrorReport (addExtraInfo ctxt ty1 ty2)
(misMatchOrCND ctxt ty1 ty2)
-- So tv is a meta tyvar, and presumably it is
, ptext (sLit "bound at") <+> ppr (ctLocOrigin implic_loc)]
; addErrorReport (addExtraInfo ctxt ty1 ty2) (msg $$ nest 2 extra) }
- | otherwise -- This can happen, by a recursive decomposition of frozen
- -- occurs check constraints
- -- Example: alpha ~ T Int alpha has frozen.
- -- Then alpha gets unified to T beta gamma
- -- So now we have T beta gamma ~ T Int (T beta gamma)
- -- Decompose to (beta ~ Int, gamma ~ T beta gamma)
- -- The (gamma ~ T beta gamma) is the occurs check, but
- -- the (beta ~ Int) isn't an error at all. So return ()
- = return ()
-
+ | otherwise
+ = pprTrace "reportTyVarEqErr" (ppr tv1 $$ ppr ty2 $$ ppr (cec_encl ctxt)) $
+ return ()
+ -- I don't think this should happen, and if it does I want to know
+ -- Trac #5130 happened because an actual type error was not
+ -- reported at all! So not reporting is pretty dangerous.
+ --
+ -- OLD, OUT OF DATE COMMENT
+ -- This can happen, by a recursive decomposition of frozen
+ -- occurs check constraints
+ -- Example: alpha ~ T Int alpha has frozen.
+ -- Then alpha gets unified to T beta gamma
+ -- So now we have T beta gamma ~ T Int (T beta gamma)
+ -- Decompose to (beta ~ Int, gamma ~ T beta gamma)
+ -- The (gamma ~ T beta gamma) is the occurs check, but
+ -- the (beta ~ Int) isn't an error at all. So return ()
where
- is_meta1 = isMetaTyVar tv1
- k1 = tyVarKind tv1
- k2 = typeKind ty2
- ty1 = mkTyVarTy tv1
+ k1 = tyVarKind tv1
+ k2 = typeKind ty2
+ ty1 = mkTyVarTy tv1
mkTyFunInfoMsg :: TcType -> TcType -> SDoc
-- See Note [Non-injective type functions]
-- Shows a bit of extra info about skolem constants
typeExtraInfoMsg implics ty
| Just tv <- tcGetTyVar_maybe ty
- , isTcTyVar tv
- , isSkolemTyVar tv
- = pprSkolTvBinding implics tv
- where
-typeExtraInfoMsg _ _ = empty -- Normal case
-
+ , isTcTyVar tv, isSkolemTyVar tv
+ , let pp_tv = quotes (ppr tv)
+ = case tcTyVarDetails tv of
+ SkolemTv {} -> pp_tv <+> ppr_skol (getSkolemInfo implics tv) (getSrcLoc tv)
+ FlatSkol {} -> pp_tv <+> ptext (sLit "is a flattening type variable")
+ RuntimeUnk {} -> pp_tv <+> ptext (sLit "is an interactive-debugger skolem")
+ MetaTv {} -> empty
+
+ | otherwise -- Normal case
+ = empty
+
+ where
+ ppr_skol UnkSkol _ = ptext (sLit "is an unknown type variable") -- Unhelpful
+ ppr_skol info loc = sep [ptext (sLit "is a rigid type variable bound by"),
+ sep [ppr info, ptext (sLit "at") <+> ppr loc]]
+
--------------------
unifyCtxt :: EqOrigin -> TidyEnv -> TcM (TidyEnv, SDoc)
unifyCtxt (UnifyOrigin { uo_actual = act_ty, uo_expected = exp_ty }) tidy_env
-- ASSUMPTION: the Insts are fully zonked
mkMonomorphismMsg ctxt inst_tvs
= do { dflags <- getDOpts
- ; traceTc "Mono" (vcat (map (pprSkolTvBinding (cec_encl ctxt)) inst_tvs))
; (tidy_env, docs) <- findGlobals ctxt (mkVarSet inst_tvs)
; return (tidy_env, mk_msg dflags docs) }
where
else empty] -- Only suggest adding "-XNoMonomorphismRestriction"
-- if it is not already set!
-
-pprSkolTvBinding :: [Implication] -> TcTyVar -> SDoc
--- Print info about the binding of a skolem tyvar,
--- or nothing if we don't have anything useful to say
-pprSkolTvBinding implics tv
- | isTcTyVar tv = quotes (ppr tv) <+> ppr_details (tcTyVarDetails tv)
- | otherwise = quotes (ppr tv) <+> ppr_skol (getSkolemInfo implics tv)
- where
- ppr_details (SkolemTv {}) = ppr_skol (getSkolemInfo implics tv)
- ppr_details (FlatSkol {}) = ptext (sLit "is a flattening type variable")
- ppr_details (RuntimeUnk {}) = ptext (sLit "is an interactive-debugger skolem")
- ppr_details (MetaTv (SigTv n) _) = ptext (sLit "is bound by the type signature for")
- <+> quotes (ppr n)
- ppr_details (MetaTv _ _) = ptext (sLit "is a meta type variable")
-
-
- ppr_skol UnkSkol = ptext (sLit "is an unknown type variable") -- Unhelpful
- ppr_skol RuntimeUnkSkol = ptext (sLit "is an unknown runtime type")
- ppr_skol info = sep [ptext (sLit "is a rigid type variable bound by"),
- sep [ppr info,
- ptext (sLit "at") <+> ppr (getSrcLoc tv)]]
-
getSkolemInfo :: [Implication] -> TcTyVar -> SkolemInfo
getSkolemInfo [] tv
= WARN( True, ptext (sLit "No skolem info:") <+> ppr tv )
--------------------------------
-- Instantiation
- tcInstTyVar, tcInstTyVars, tcInstSigTyVars,
- tcInstType, instMetaTyVar,
+ tcInstTyVars, tcInstSigTyVars,
+ tcInstType,
tcInstSkolTyVars, tcInstSuperSkolTyVars, tcInstSkolTyVar, tcInstSkolType,
tcSkolDFunType, tcSuperSkolTyVars,
tcInstSigTyVars :: [TyVar] -> TcM [TcTyVar]
-- Make meta SigTv type variables for patten-bound scoped type varaibles
-- We use SigTvs for them, so that they can't unify with arbitrary types
-tcInstSigTyVars = mapM (\tv -> instMetaTyVar (SigTv (tyVarName tv)) tv)
- -- ToDo: the "function binding site is bogus
+tcInstSigTyVars = mapM tcInstSigTyVar
+
+tcInstSigTyVar :: TyVar -> TcM TcTyVar
+tcInstSigTyVar tyvar
+ = do { uniq <- newMetaUnique
+ ; ref <- newMutVar Flexi
+ ; let name = setNameUnique (tyVarName tyvar) uniq
+ -- Use the same OccName so that the tidy-er
+ -- doesn't rename 'a' to 'a0' etc
+ kind = tyVarKind tyvar
+ ; return (mkTcTyVar name kind (MetaTv SigTv ref)) }
\end{code}
; ref <- newMutVar Flexi
; let name = mkTcTyVarName uniq s
s = case meta_info of
- TauTv -> fsLit "t"
- TcsTv -> fsLit "u"
- SigTv _ -> fsLit "a"
+ TauTv -> fsLit "t"
+ TcsTv -> fsLit "u"
+ SigTv -> fsLit "a"
; return (mkTcTyVar name kind (MetaTv meta_info ref)) }
mkTcTyVarName :: Unique -> FastString -> Name
-- leaving the un-cluttered names free for user names
mkTcTyVarName uniq str = mkSysTvName uniq str
-instMetaTyVar :: MetaInfo -> TyVar -> TcM TcTyVar
--- Make a new meta tyvar whose Name and Kind
--- come from an existing TyVar
-instMetaTyVar meta_info tyvar
- = do { uniq <- newMetaUnique
- ; ref <- newMutVar Flexi
- ; let name = mkSystemName uniq (getOccName tyvar)
- kind = tyVarKind tyvar
- ; return (mkTcTyVar name kind (MetaTv meta_info ref)) }
-
readMetaTyVar :: TyVar -> TcM MetaDetails
readMetaTyVar tyvar = ASSERT2( isMetaTyVar tyvar, ppr tyvar )
readMutVar (metaTvRef tyvar)
newFlexiTyVarTys :: Int -> Kind -> TcM [TcType]
newFlexiTyVarTys n kind = mapM newFlexiTyVarTy (nOfThem n kind)
-tcInstTyVar :: TyVar -> TcM TcTyVar
--- Instantiate with a META type variable
-tcInstTyVar tyvar = instMetaTyVar TauTv tyvar
-
tcInstTyVars :: [TyVar] -> TcM ([TcTyVar], [TcType], TvSubst)
-- Instantiate with META type variables
tcInstTyVars tyvars
-- Since the tyvars are freshly made,
-- they cannot possibly be captured by
-- any existing for-alls. Hence zipTopTvSubst
+
+tcInstTyVar :: TyVar -> TcM TcTyVar
+-- Make a new unification variable tyvar whose Name and Kind
+-- come from an existing TyVar
+tcInstTyVar tyvar
+ = do { uniq <- newMetaUnique
+ ; ref <- newMutVar Flexi
+ ; let name = mkSystemName uniq (getOccName tyvar)
+ kind = tyVarKind tyvar
+ ; return (mkTcTyVar name kind (MetaTv TauTv ref)) }
\end{code}
-- polymorphic Ids, and are now checking that their RHS
-- constraints are satisfied.
- | RuntimeUnkSkol -- a type variable used to represent an unknown
- -- runtime type (used in the GHCi debugger)
-
| BracketSkol -- Template Haskell bracket
| UnkSkol -- Unhelpful info (until I improve it)
-- UnkSkol
-- For type variables the others are dealt with by pprSkolTvBinding.
-- For Insts, these cases should not happen
-pprSkolInfo UnkSkol = WARN( True, text "pprSkolInfo: UnkSkol" ) ptext (sLit "UnkSkol")
-pprSkolInfo RuntimeUnkSkol = WARN( True, text "pprSkolInfo: RuntimeUnkSkol" ) ptext (sLit "RuntimeUnkSkol")
+pprSkolInfo UnkSkol = WARN( True, text "pprSkolInfo: UnkSkol" ) ptext (sLit "UnkSkol")
\end{code}
#ifdef DEBUG
; count <- TcM.readTcRef step_count
; when (count > 0) $
- TcM.dumpTcRn (ptext (sLit "Constraint solver steps =") <+> int count <+> ppr context)
+ TcM.debugDumpTcRn (ptext (sLit "Constraint solver steps =")
+ <+> int count <+> ppr context)
#endif
-- And return
; ev_binds <- TcM.readTcRef evb_ref
-- A TauTv is always filled in with a tau-type, which
-- never contains any ForAlls
- | SigTv Name -- A variant of TauTv, except that it should not be
+ | SigTv -- A variant of TauTv, except that it should not be
-- unified with a type, only with a type variable
-- SigTvs are only distinguished to improve error messages
-- see Note [Signature skolems]
-- The MetaDetails, if filled in, will
-- always be another SigTv or a SkolemTv
- -- The Name is the name of the function from whose
- -- type signature we got this skolem
| TcsTv -- A MetaTv allocated by the constraint solver
-- Its particular property is that it is always "touchable"
\begin{code}
pprTcTyVarDetails :: TcTyVarDetails -> SDoc
-- For debugging
-pprTcTyVarDetails (SkolemTv {}) = ptext (sLit "sk")
-pprTcTyVarDetails (RuntimeUnk {}) = ptext (sLit "rt")
-pprTcTyVarDetails (FlatSkol {}) = ptext (sLit "fsk")
-pprTcTyVarDetails (MetaTv TauTv _) = ptext (sLit "tau")
-pprTcTyVarDetails (MetaTv TcsTv _) = ptext (sLit "tcs")
-pprTcTyVarDetails (MetaTv (SigTv _) _) = ptext (sLit "sig")
+pprTcTyVarDetails (SkolemTv {}) = ptext (sLit "sk")
+pprTcTyVarDetails (RuntimeUnk {}) = ptext (sLit "rt")
+pprTcTyVarDetails (FlatSkol {}) = ptext (sLit "fsk")
+pprTcTyVarDetails (MetaTv TauTv _) = ptext (sLit "tau")
+pprTcTyVarDetails (MetaTv TcsTv _) = ptext (sLit "tcs")
+pprTcTyVarDetails (MetaTv SigTv _) = ptext (sLit "sig")
pprUserTypeCtxt :: UserTypeCtxt -> SDoc
pprUserTypeCtxt (FunSigCtxt n) = ptext (sLit "the type signature for") <+> quotes (ppr n)
-- not a SigTv
= ASSERT( isTcTyVar tv)
case tcTyVarDetails tv of
- MetaTv (SigTv _) _ -> False
- _ -> True
+ MetaTv SigTv _ -> False
+ _ -> True
isSkolemTyVar tv
= ASSERT2( isTcTyVar tv, ppr tv )
isSigTyVar tv
= ASSERT( isTcTyVar tv )
case tcTyVarDetails tv of
- MetaTv (SigTv _) _ -> True
- _ -> False
+ MetaTv SigTv _ -> True
+ _ -> False
metaTvRef :: TyVar -> IORef MetaDetails
metaTvRef tv
ty1 = mkTyVarTy tv1
ty2 = mkTyVarTy tv2
- nicer_to_update_tv1 _ (SigTv _) = True
- nicer_to_update_tv1 (SigTv _) _ = False
+ nicer_to_update_tv1 _ SigTv = True
+ nicer_to_update_tv1 SigTv _ = False
nicer_to_update_tv1 _ _ = isSystemName (Var.varName tv1)
-- Try not to update SigTvs; and try to update sys-y type
-- variables in preference to ones gotten (say) by
-- * Error handling and debugging utilities
pprPanic, pprSorry, assertPprPanic, pprPanicFastInt, pprPgmError,
- pprTrace, warnPprTrace,
+ pprTrace, pprDefiniteTrace, warnPprTrace,
trace, pgmError, panic, sorry, panicFastInt, assertPanic
) where
| opt_NoDebugOutput = x
| otherwise = pprAndThen trace str doc x
+pprDefiniteTrace :: String -> SDoc -> a -> a
+-- ^ Same as pprTrace, but show even if -dno-debug-output is on
+pprDefiniteTrace str doc x = pprAndThen trace str doc x
pprPanicFastInt :: String -> SDoc -> FastInt
-- ^ Specialization of pprPanic that can be safely used with 'FastInt'
projects / ghc-hetmet.git / commitdiff