From 871b63e4ea95d4c516d31378d0475167e75caa01 Mon Sep 17 00:00:00 2001
From: Simon Peyton Jones <simonpj@microsoft.com>
Date: Tue, 28 Feb 2017 20:20:21 -0500
Subject: [PATCH] Improve pretty-printing of types
When doing debug-printing it's really important that the free vars
of a type are printed with their uniques. The IfaceTcTyVar thing
was a stab in that direction, but it only worked for TcTyVars, not
TyVars.
This patch does it properly, by keeping track of the free vars of the
type when translating Type -> IfaceType, and passing that down through
toIfaceTypeX. Then when we find a variable, look in that set, and
translate it to IfaceFreeTyVar if so. (I renamed IfaceTcTyVar to
IfaceFreeTyVar.)
Fiddly but not difficult.
Reviewers: austin, goldfire, bgamari
Reviewed By: bgamari
Subscribers: thomie
Differential Revision: https://phabricator.haskell.org/D3201
---
compiler/backpack/RnModIface.hs | 4 +-
compiler/iface/IfaceSyn.hs | 2 +-
compiler/iface/IfaceType.hs | 38 ++---
compiler/iface/TcIface.hs | 2 +-
compiler/iface/ToIface.hs | 147 ++++++++++--------
compiler/iface/ToIface.hs-boot | 2 +
compiler/typecheck/TcRnTypes.hs | 5 +-
compiler/types/TyCoRep.hs | 37 +++--
compiler/types/Type.hs | 2 +-
compiler/types/Type.hs-boot | 2 +-
.../tests/deriving/should_fail/T7148.stderr | 8 +-
testsuite/tests/th/T8761.stderr | 57 ++++---
.../typecheck/should_fail/T12785b.stderr | 15 +-
13 files changed, 175 insertions(+), 146 deletions(-)
diff --git a/compiler/backpack/RnModIface.hs b/compiler/backpack/RnModIface.hs
index 7180918ff720..7696d5f07586 100644
--- a/compiler/backpack/RnModIface.hs
+++ b/compiler/backpack/RnModIface.hs
@@ -674,8 +674,8 @@ rnIfaceIdDetails (IfRecSelId (Right decl) b) = IfRecSelId <$> fmap Right (rnIfac
rnIfaceIdDetails details = pure details
rnIfaceType :: Rename IfaceType
-rnIfaceType (IfaceTcTyVar n) = pure (IfaceTcTyVar n)
-rnIfaceType (IfaceTyVar n) = pure (IfaceTyVar n)
+rnIfaceType (IfaceFreeTyVar n) = pure (IfaceFreeTyVar n)
+rnIfaceType (IfaceTyVar n) = pure (IfaceTyVar n)
rnIfaceType (IfaceAppTy t1 t2)
= IfaceAppTy <$> rnIfaceType t1 <*> rnIfaceType t2
rnIfaceType (IfaceLitTy l) = return (IfaceLitTy l)
diff --git a/compiler/iface/IfaceSyn.hs b/compiler/iface/IfaceSyn.hs
index 0a50e860a53a..5d9688e9a662 100644
--- a/compiler/iface/IfaceSyn.hs
+++ b/compiler/iface/IfaceSyn.hs
@@ -1329,7 +1329,7 @@ freeNamesIfTcArgs (ITC_Invis k ks) = freeNamesIfKind k &&& freeNamesIfTcArgs ks
freeNamesIfTcArgs ITC_Nil = emptyNameSet
freeNamesIfType :: IfaceType -> NameSet
-freeNamesIfType (IfaceTcTyVar _) = emptyNameSet
+freeNamesIfType (IfaceFreeTyVar _) = emptyNameSet
freeNamesIfType (IfaceTyVar _) = emptyNameSet
freeNamesIfType (IfaceAppTy s t) = freeNamesIfType s &&& freeNamesIfType t
freeNamesIfType (IfaceTyConApp tc ts) = freeNamesIfTc tc &&& freeNamesIfTcArgs ts
diff --git a/compiler/iface/IfaceType.hs b/compiler/iface/IfaceType.hs
index 75a2afcc7d60..41cf4f69e4c6 100644
--- a/compiler/iface/IfaceType.hs
+++ b/compiler/iface/IfaceType.hs
@@ -110,15 +110,15 @@ data IfaceOneShot -- See Note [Preserve OneShotInfo] in CoreTicy
type IfaceKind = IfaceType
data IfaceType -- A kind of universal type, used for types and kinds
- = IfaceTcTyVar TyVar -- See Note [TcTyVars in IfaceType]
- | IfaceTyVar IfLclName -- Type/coercion variable only, not tycon
- | IfaceLitTy IfaceTyLit
- | IfaceAppTy IfaceType IfaceType
- | IfaceFunTy IfaceType IfaceType
- | IfaceDFunTy IfaceType IfaceType
- | IfaceForAllTy IfaceForAllBndr IfaceType
- | IfaceTyConApp IfaceTyCon IfaceTcArgs -- Not necessarily saturated
- -- Includes newtypes, synonyms, tuples
+ = IfaceFreeTyVar TyVar -- See Note [Free tyvars in IfaceType]
+ | IfaceTyVar IfLclName -- Type/coercion variable only, not tycon
+ | IfaceLitTy IfaceTyLit
+ | IfaceAppTy IfaceType IfaceType
+ | IfaceFunTy IfaceType IfaceType
+ | IfaceDFunTy IfaceType IfaceType
+ | IfaceForAllTy IfaceForAllBndr IfaceType
+ | IfaceTyConApp IfaceTyCon IfaceTcArgs -- Not necessarily saturated
+ -- Includes newtypes, synonyms, tuples
| IfaceCastTy IfaceType IfaceCoercion
| IfaceCoercionTy IfaceCoercion
@@ -186,7 +186,7 @@ data IfaceTyConSort = IfaceNormalTyCon -- ^ a regular tycon
-- details.
deriving (Eq)
-{- Note [TcTyVars in IfaceType]
+{- Note [Free tyvars in IfaceType]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Nowadays (since Nov 16, 2016) we pretty-print a Type by converting to an
IfaceType and pretty printing that. This eliminates a lot of
@@ -198,11 +198,11 @@ when using -ddump-tc-trace) we print a lot of /open/ types. These
types are full of TcTyVars, and it's absolutely crucial to print them
in their full glory, with their unique, TcTyVarDetails etc.
-So we simply embed a TcTyVar in IfaceType with the IfaceTcTyVar constructor.
+So we simply embed a TyVar in IfaceType with the IfaceFreeTyVar constructor.
Note that:
-* We never expect to serialise an IfaceTcTyVar into an interface file, nor
- to deserialise one. IfaceTcTyVar is used only in the "convert to IfaceType
+* We never expect to serialise an IfaceFreeTyVar into an interface file, nor
+ to deserialise one. IfaceFreeTyVar is used only in the "convert to IfaceType
and then pretty-print" pipeline.
@@ -345,7 +345,7 @@ ifTypeIsVarFree :: IfaceType -> Bool
ifTypeIsVarFree ty = go ty
where
go (IfaceTyVar {}) = False
- go (IfaceTcTyVar {}) = False
+ go (IfaceFreeTyVar {}) = False
go (IfaceAppTy fun arg) = go fun && go arg
go (IfaceFunTy arg res) = go arg && go res
go (IfaceDFunTy arg res) = go arg && go res
@@ -375,7 +375,7 @@ substIfaceType :: IfaceTySubst -> IfaceType -> IfaceType
substIfaceType env ty
= go ty
where
- go (IfaceTcTyVar tv) = IfaceTcTyVar tv
+ go (IfaceFreeTyVar tv) = IfaceFreeTyVar tv
go (IfaceTyVar tv) = substIfaceTyVar env tv
go (IfaceAppTy t1 t2) = IfaceAppTy (go t1) (go t2)
go (IfaceFunTy t1 t2) = IfaceFunTy (go t1) (go t2)
@@ -473,7 +473,7 @@ extendIfRnEnv2 IRV2 { ifenvL = lenv
-- See Note [No kind check in ifaces]
eqIfaceType :: IfRnEnv2 -> IfaceType -> IfaceType -> Bool
-eqIfaceType _ (IfaceTcTyVar tv1) (IfaceTcTyVar tv2)
+eqIfaceType _ (IfaceFreeTyVar tv1) (IfaceFreeTyVar tv2)
= tv1 == tv2 -- Should not happen
eqIfaceType env (IfaceTyVar tv1) (IfaceTyVar tv2) =
case (rnIfOccL env tv1, rnIfOccR env tv2) of
@@ -667,7 +667,7 @@ pprIfaceType = eliminateRuntimeRep (ppr_ty TopPrec)
pprParendIfaceType = eliminateRuntimeRep (ppr_ty TyConPrec)
ppr_ty :: TyPrec -> IfaceType -> SDoc
-ppr_ty _ (IfaceTcTyVar tyvar) = ppr tyvar -- This is the main reson for IfaceTcTyVar!
+ppr_ty _ (IfaceFreeTyVar tyvar) = ppr tyvar -- This is the main reson for IfaceFreeTyVar!
ppr_ty _ (IfaceTyVar tyvar) = ppr tyvar -- See Note [TcTyVars in IfaceType]
ppr_ty ctxt_prec (IfaceTyConApp tc tys) = pprTyTcApp ctxt_prec tc tys
ppr_ty _ (IfaceTupleTy i p tys) = pprTuple i p tys
@@ -1322,8 +1322,8 @@ pprIfaceContext [pred] = ppr_ty TyOpPrec pred
pprIfaceContext preds = parens (fsep (punctuate comma (map ppr preds)))
instance Binary IfaceType where
- put_ _ (IfaceTcTyVar tv)
- = pprPanic "Can't serialise IfaceTcTyVar" (ppr tv)
+ put_ _ (IfaceFreeTyVar tv)
+ = pprPanic "Can't serialise IfaceFreeTyVar" (ppr tv)
put_ bh (IfaceForAllTy aa ab) = do
putByte bh 0
diff --git a/compiler/iface/TcIface.hs b/compiler/iface/TcIface.hs
index d8461f364f62..b6b898f23081 100644
--- a/compiler/iface/TcIface.hs
+++ b/compiler/iface/TcIface.hs
@@ -1181,7 +1181,7 @@ tcIfaceType :: IfaceType -> IfL Type
tcIfaceType = go
where
go (IfaceTyVar n) = TyVarTy <$> tcIfaceTyVar n
- go (IfaceTcTyVar n) = pprPanic "tcIfaceType:IfaceTcTyVar" (ppr n)
+ go (IfaceFreeTyVar n) = pprPanic "tcIfaceType:IfaceFreeTyVar" (ppr n)
go (IfaceAppTy t1 t2) = AppTy <$> go t1 <*> go t2
go (IfaceLitTy l) = LitTy <$> tcIfaceTyLit l
go (IfaceFunTy t1 t2) = FunTy <$> go t1 <*> go t2
diff --git a/compiler/iface/ToIface.hs b/compiler/iface/ToIface.hs
index c0229b8e6293..59184dcab033 100644
--- a/compiler/iface/ToIface.hs
+++ b/compiler/iface/ToIface.hs
@@ -11,7 +11,7 @@ module ToIface
, toIfaceTyVarBinders
, toIfaceTyVar
-- * Types
- , toIfaceType
+ , toIfaceType, toIfaceTypeX
, toIfaceKind
, toIfaceTcArgs
, toIfaceTyCon
@@ -64,6 +64,7 @@ import FastString
import Util
import Var
import VarEnv
+import VarSet
import TyCoRep
import Demand ( isTopSig )
@@ -105,44 +106,51 @@ toIfaceKind = toIfaceType
---------------------
toIfaceType :: Type -> IfaceType
+toIfaceType = toIfaceTypeX emptyVarSet
+
+toIfaceTypeX :: VarSet -> Type -> IfaceType
+-- (toIfaceTypeX free ty)
+-- translates the tyvars in 'free' as IfaceFreeTyVars
+--
-- Synonyms are retained in the interface type
-toIfaceType (TyVarTy tv) -- See Note [TcTyVars in IfaceType] in IfaceType
- | isTcTyVar tv = IfaceTcTyVar tv
- | otherwise = IfaceTyVar (toIfaceTyVar tv)
-toIfaceType (AppTy t1 t2) = IfaceAppTy (toIfaceType t1) (toIfaceType t2)
-toIfaceType (LitTy n) = IfaceLitTy (toIfaceTyLit n)
-toIfaceType (ForAllTy b t) = IfaceForAllTy (toIfaceForAllBndr b) (toIfaceType t)
-toIfaceType (FunTy t1 t2)
- | isPredTy t1 = IfaceDFunTy (toIfaceType t1) (toIfaceType t2)
- | otherwise = IfaceFunTy (toIfaceType t1) (toIfaceType t2)
-toIfaceType (CastTy ty co) = IfaceCastTy (toIfaceType ty) (toIfaceCoercion co)
-toIfaceType (CoercionTy co) = IfaceCoercionTy (toIfaceCoercion co)
-
-toIfaceType (TyConApp tc tys)
+toIfaceTypeX fr (TyVarTy tv) -- See Note [TcTyVars in IfaceType] in IfaceType
+ | tv `elemVarSet` fr = IfaceFreeTyVar tv
+ | otherwise = IfaceTyVar (toIfaceTyVar tv)
+toIfaceTypeX fr (AppTy t1 t2) = IfaceAppTy (toIfaceTypeX fr t1) (toIfaceTypeX fr t2)
+toIfaceTypeX _ (LitTy n) = IfaceLitTy (toIfaceTyLit n)
+toIfaceTypeX fr (ForAllTy b t) = IfaceForAllTy (toIfaceForAllBndr b)
+ (toIfaceTypeX (fr `delVarSet` binderVar b) t)
+toIfaceTypeX fr (FunTy t1 t2)
+ | isPredTy t1 = IfaceDFunTy (toIfaceTypeX fr t1) (toIfaceTypeX fr t2)
+ | otherwise = IfaceFunTy (toIfaceTypeX fr t1) (toIfaceTypeX fr t2)
+toIfaceTypeX fr (CastTy ty co) = IfaceCastTy (toIfaceTypeX fr ty) (toIfaceCoercionX fr co)
+toIfaceTypeX fr (CoercionTy co) = IfaceCoercionTy (toIfaceCoercionX fr co)
+
+toIfaceTypeX fr (TyConApp tc tys)
-- tuples
| Just sort <- tyConTuple_maybe tc
, n_tys == arity
- = IfaceTupleTy sort IsNotPromoted (toIfaceTcArgs tc tys)
+ = IfaceTupleTy sort IsNotPromoted (toIfaceTcArgsX fr tc tys)
| Just dc <- isPromotedDataCon_maybe tc
, isTupleDataCon dc
, n_tys == 2*arity
- = IfaceTupleTy BoxedTuple IsPromoted (toIfaceTcArgs tc (drop arity tys))
+ = IfaceTupleTy BoxedTuple IsPromoted (toIfaceTcArgsX fr tc (drop arity tys))
-- type equalities: see Note [Equality predicates in IfaceType]
| tyConName tc == eqTyConName
= let info = IfaceTyConInfo IsNotPromoted (IfaceEqualityTyCon True)
- in IfaceTyConApp (IfaceTyCon (tyConName tc) info) (toIfaceTcArgs tc tys)
+ in IfaceTyConApp (IfaceTyCon (tyConName tc) info) (toIfaceTcArgsX fr tc tys)
| tc `elem` [ eqPrimTyCon, eqReprPrimTyCon, heqTyCon ]
, [k1, k2, _t1, _t2] <- tys
= let homogeneous = k1 `eqType` k2
info = IfaceTyConInfo IsNotPromoted (IfaceEqualityTyCon homogeneous)
- in IfaceTyConApp (IfaceTyCon (tyConName tc) info) (toIfaceTcArgs tc tys)
+ in IfaceTyConApp (IfaceTyCon (tyConName tc) info) (toIfaceTcArgsX fr tc tys)
-- other applications
| otherwise
- = IfaceTyConApp (toIfaceTyCon tc) (toIfaceTcArgs tc tys)
+ = IfaceTyConApp (toIfaceTyCon tc) (toIfaceTcArgsX fr tc tys)
where
arity = tyConArity tc
n_tys = length tys
@@ -200,50 +208,63 @@ toIfaceTyLit (StrTyLit x) = IfaceStrTyLit x
----------------
toIfaceCoercion :: Coercion -> IfaceCoercion
-toIfaceCoercion (Refl r ty) = IfaceReflCo r (toIfaceType ty)
-toIfaceCoercion co@(TyConAppCo r tc cos)
- | tc `hasKey` funTyConKey
- , [_,_,_,_] <- cos = pprPanic "toIfaceCoercion" (ppr co)
- | otherwise = IfaceTyConAppCo r (toIfaceTyCon tc)
- (map toIfaceCoercion cos)
-toIfaceCoercion (AppCo co1 co2) = IfaceAppCo (toIfaceCoercion co1)
- (toIfaceCoercion co2)
-toIfaceCoercion (ForAllCo tv k co) = IfaceForAllCo (toIfaceTvBndr tv)
- (toIfaceCoercion k)
- (toIfaceCoercion co)
-toIfaceCoercion (FunCo r co1 co2) = IfaceFunCo r (toIfaceCoercion co1)
- (toIfaceCoercion co2)
-toIfaceCoercion (CoVarCo cv) = IfaceCoVarCo (toIfaceCoVar cv)
-toIfaceCoercion (AxiomInstCo con ind cos)
- = IfaceAxiomInstCo (coAxiomName con) ind
- (map toIfaceCoercion cos)
-toIfaceCoercion (UnivCo p r t1 t2) = IfaceUnivCo (toIfaceUnivCoProv p) r
- (toIfaceType t1)
- (toIfaceType t2)
-toIfaceCoercion (SymCo co) = IfaceSymCo (toIfaceCoercion co)
-toIfaceCoercion (TransCo co1 co2) = IfaceTransCo (toIfaceCoercion co1)
- (toIfaceCoercion co2)
-toIfaceCoercion (NthCo d co) = IfaceNthCo d (toIfaceCoercion co)
-toIfaceCoercion (LRCo lr co) = IfaceLRCo lr (toIfaceCoercion co)
-toIfaceCoercion (InstCo co arg) = IfaceInstCo (toIfaceCoercion co)
- (toIfaceCoercion arg)
-toIfaceCoercion (CoherenceCo c1 c2) = IfaceCoherenceCo (toIfaceCoercion c1)
- (toIfaceCoercion c2)
-toIfaceCoercion (KindCo c) = IfaceKindCo (toIfaceCoercion c)
-toIfaceCoercion (SubCo co) = IfaceSubCo (toIfaceCoercion co)
-toIfaceCoercion (AxiomRuleCo co cs) = IfaceAxiomRuleCo (coaxrName co)
- (map toIfaceCoercion cs)
-
-toIfaceUnivCoProv :: UnivCoProvenance -> IfaceUnivCoProv
-toIfaceUnivCoProv UnsafeCoerceProv = IfaceUnsafeCoerceProv
-toIfaceUnivCoProv (PhantomProv co) = IfacePhantomProv (toIfaceCoercion co)
-toIfaceUnivCoProv (ProofIrrelProv co) = IfaceProofIrrelProv (toIfaceCoercion co)
-toIfaceUnivCoProv (PluginProv str) = IfacePluginProv str
-toIfaceUnivCoProv (HoleProv h) = IfaceHoleProv (chUnique h)
+toIfaceCoercion = toIfaceCoercionX emptyVarSet
+
+toIfaceCoercionX :: VarSet -> Coercion -> IfaceCoercion
+-- (toIfaceCoercionX free ty)
+-- translates the tyvars in 'free' as IfaceFreeTyVars
+toIfaceCoercionX fr co
+ = go co
+ where
+ go (Refl r ty) = IfaceReflCo r (toIfaceType ty)
+ go (CoVarCo cv) = IfaceCoVarCo (toIfaceCoVar cv)
+ go (AppCo co1 co2) = IfaceAppCo (go co1) (go co2)
+ go (SymCo co) = IfaceSymCo (go co)
+ go (TransCo co1 co2) = IfaceTransCo (go co1) (go co2)
+ go (NthCo d co) = IfaceNthCo d (go co)
+ go (LRCo lr co) = IfaceLRCo lr (go co)
+ go (InstCo co arg) = IfaceInstCo (go co) (go arg)
+ go (CoherenceCo c1 c2) = IfaceCoherenceCo (go c1) (go c2)
+ go (KindCo c) = IfaceKindCo (go c)
+ go (SubCo co) = IfaceSubCo (go co)
+ go (AxiomRuleCo co cs) = IfaceAxiomRuleCo (coaxrName co) (map go cs)
+ go (AxiomInstCo c i cs) = IfaceAxiomInstCo (coAxiomName c) i (map go cs)
+ go (UnivCo p r t1 t2) = IfaceUnivCo (go_prov p) r
+ (toIfaceTypeX fr t1)
+ (toIfaceTypeX fr t2)
+ go (TyConAppCo r tc cos)
+ | tc `hasKey` funTyConKey
+ , [_,_,_,_] <- cos = pprPanic "toIfaceCoercion" (ppr co)
+ | otherwise = IfaceTyConAppCo r (toIfaceTyCon tc) (map go cos)
+ go (FunCo r co1 co2) = IfaceFunCo r (toIfaceCoercion co1)
+ (toIfaceCoercion co2)
+
+ go (ForAllCo tv k co) = IfaceForAllCo (toIfaceTvBndr tv)
+ (toIfaceCoercionX fr' k)
+ (toIfaceCoercionX fr' co)
+ where
+ fr' = fr `delVarSet` tv
+
+ go_prov :: UnivCoProvenance -> IfaceUnivCoProv
+ go_prov UnsafeCoerceProv = IfaceUnsafeCoerceProv
+ go_prov (PhantomProv co) = IfacePhantomProv (go co)
+ go_prov (ProofIrrelProv co) = IfaceProofIrrelProv (go co)
+ go_prov (PluginProv str) = IfacePluginProv str
+ go_prov (HoleProv h) = IfaceHoleProv (chUnique h)
toIfaceTcArgs :: TyCon -> [Type] -> IfaceTcArgs
+toIfaceTcArgs = toIfaceTcArgsX emptyVarSet
+
+toIfaceTcArgsX :: VarSet -> TyCon -> [Type] -> IfaceTcArgs
-- See Note [Suppressing invisible arguments]
-toIfaceTcArgs tc ty_args
+-- We produce a result list of args describing visiblity
+-- The awkward case is
+-- T :: forall k. * -> k
+-- And consider
+-- T (forall j. blah) * blib
+-- Is 'blib' visible? It depends on the visibility flag on j,
+-- so we have to substitute for k. Annoying!
+toIfaceTcArgsX fr tc ty_args
= go (mkEmptyTCvSubst in_scope) (tyConKind tc) ty_args
where
in_scope = mkInScopeSet (tyCoVarsOfTypes ty_args)
@@ -256,16 +277,16 @@ toIfaceTcArgs tc ty_args
| isVisibleArgFlag vis = ITC_Vis t' ts'
| otherwise = ITC_Invis t' ts'
where
- t' = toIfaceType t
+ t' = toIfaceTypeX fr t
ts' = go (extendTvSubst env tv t) res ts
go env (FunTy _ res) (t:ts) -- No type-class args in tycon apps
- = ITC_Vis (toIfaceType t) (go env res ts)
+ = ITC_Vis (toIfaceTypeX fr t) (go env res ts)
go env (TyVarTy tv) ts
| Just ki <- lookupTyVar env tv = go env ki ts
go env kind (t:ts) = WARN( True, ppr tc $$ ppr (tyConKind tc) $$ ppr ty_args )
- ITC_Vis (toIfaceType t) (go env kind ts) -- Ill-kinded
+ ITC_Vis (toIfaceTypeX fr t) (go env kind ts) -- Ill-kinded
tidyToIfaceType :: TidyEnv -> Type -> IfaceType
tidyToIfaceType env ty = toIfaceType (tidyType env ty)
diff --git a/compiler/iface/ToIface.hs-boot b/compiler/iface/ToIface.hs-boot
index bf6c120d8eac..04ceab673f1b 100644
--- a/compiler/iface/ToIface.hs-boot
+++ b/compiler/iface/ToIface.hs-boot
@@ -4,9 +4,11 @@ import {-# SOURCE #-} TyCoRep
import {-# SOURCE #-} IfaceType
import Var ( TyVar, TyVarBinder )
import TyCon ( TyCon )
+import VarSet( VarSet )
-- For TyCoRep
toIfaceType :: Type -> IfaceType
+toIfaceTypeX :: VarSet -> Type -> IfaceType
toIfaceTyLit :: TyLit -> IfaceTyLit
toIfaceForAllBndr :: TyVarBinder -> IfaceForAllBndr
toIfaceTvBndr :: TyVar -> IfaceTvBndr
diff --git a/compiler/typecheck/TcRnTypes.hs b/compiler/typecheck/TcRnTypes.hs
index f0ca574cd4d3..67eb982b9160 100644
--- a/compiler/typecheck/TcRnTypes.hs
+++ b/compiler/typecheck/TcRnTypes.hs
@@ -1765,8 +1765,9 @@ tyCoFVsOfWC (WC { wc_simple = simple, wc_impl = implic, wc_insol = insol })
tyCoFVsOfImplic :: Implication -> FV
-- Only called on *zonked* things, hence no need to worry about flatten-skolems
tyCoFVsOfImplic (Implic { ic_skols = skols
- , ic_given = givens, ic_wanted = wanted })
- = FV.delFVs (mkVarSet skols)
+ , ic_given = givens
+ , ic_wanted = wanted })
+ = FV.delFVs (mkVarSet skols `unionVarSet` mkVarSet givens)
(tyCoFVsOfWC wanted `unionFV` tyCoFVsOfTypes (map evVarPred givens))
tyCoFVsOfBag :: (a -> FV) -> Bag a -> FV
diff --git a/compiler/types/TyCoRep.hs b/compiler/types/TyCoRep.hs
index 1e90fa7aeecc..6b693ef97bfe 100644
--- a/compiler/types/TyCoRep.hs
+++ b/compiler/types/TyCoRep.hs
@@ -61,7 +61,7 @@ module TyCoRep (
pprTyVar, pprTyVars,
pprThetaArrowTy, pprClassPred,
pprKind, pprParendKind, pprTyLit,
- TyPrec(..), maybeParen, pprTcAppCo, pprTcAppTy,
+ TyPrec(..), maybeParen, pprTcAppCo,
pprPrefixApp, pprArrowChain,
pprDataCons, ppSuggestExplicitKinds,
@@ -137,12 +137,14 @@ import {-# SOURCE #-} DataCon( dataConFullSig
, DataCon, filterEqSpec )
import {-# SOURCE #-} Type( isPredTy, isCoercionTy, mkAppTy
, tyCoVarsOfTypesWellScoped
+ , tyCoVarsOfTypeWellScoped
, coreView, typeKind )
-- Transitively pulls in a LOT of stuff, better to break the loop
import {-# SOURCE #-} Coercion
import {-# SOURCE #-} ConLike ( ConLike(..), conLikeName )
-import {-# SOURCE #-} ToIface
+import {-# SOURCE #-} ToIface( toIfaceTypeX, toIfaceTyLit, toIfaceForAllBndr
+ , toIfaceTyCon, toIfaceTcArgs, toIfaceCoercion )
-- friends:
import IfaceType
@@ -2460,7 +2462,14 @@ pprParendKind = pprParendType
tidyToIfaceType :: Type -> IfaceType
-- It's vital to tidy before converting to an IfaceType
-- or nested binders will become indistinguishable!
-tidyToIfaceType = toIfaceType . tidyTopType
+--
+-- Also for the free type variables, tell toIfaceTypeX to
+-- leave them as IfaceFreeTyVar. This is super-important
+-- for debug printing.
+tidyToIfaceType ty = toIfaceTypeX (mkVarSet free_tcvs) (tidyType env ty)
+ where
+ env = tidyFreeTyCoVars emptyTidyEnv free_tcvs
+ free_tcvs = tyCoVarsOfTypeWellScoped ty
------------
pprClassPred :: Class -> [Type] -> SDoc
@@ -2483,7 +2492,7 @@ instance Outputable TyLit where
------------------
pprSigmaType :: Type -> SDoc
-pprSigmaType = (pprIfaceSigmaType ShowForAllWhen) . tidyToIfaceType
+pprSigmaType = pprIfaceSigmaType ShowForAllWhen . tidyToIfaceType
pprForAll :: [TyVarBinder] -> SDoc
pprForAll tvs = pprIfaceForAll (map toIfaceForAllBndr tvs)
@@ -2578,12 +2587,10 @@ pprDataConWithArgs dc = sep [forAllDoc, thetaDoc, ppr dc <+> argsDoc]
pprTypeApp :: TyCon -> [Type] -> SDoc
-pprTypeApp = pprTcAppTy TopPrec
-
-pprTcAppTy :: TyPrec -> TyCon -> [Type] -> SDoc
-pprTcAppTy p tc tys
+pprTypeApp tc tys
+ = pprIfaceTypeApp TopPrec (toIfaceTyCon tc)
+ (toIfaceTcArgs tc tys)
-- TODO: toIfaceTcArgs seems rather wasteful here
- = pprIfaceTypeApp p (toIfaceTyCon tc) (toIfaceTcArgs tc tys)
pprTcAppCo :: TyPrec -> (TyPrec -> Coercion -> SDoc)
-> TyCon -> [Coercion] -> SDoc
@@ -2649,16 +2656,16 @@ getHelpfulOccName tyvar = occ1
where
name = tyVarName tyvar
occ = getOccName name
- -- System Names are for unification variables;
+ -- A TcTyVar with a System Name is probably a unification variable;
-- when we tidy them we give them a trailing "0" (or 1 etc)
-- so that they don't take precedence for the un-modified name
-- Plus, indicating a unification variable in this way is a
-- helpful clue for users
occ1 | isSystemName name
- = if isTyVar tyvar
- then mkTyVarOcc (occNameString occ ++ "0")
- else mkVarOcc (occNameString occ ++ "0")
- | otherwise = occ
+ , isTcTyVar tyvar
+ = mkTyVarOcc (occNameString occ ++ "0")
+ | otherwise
+ = occ
tidyTyVarBinder :: TidyEnv -> TyVarBndr TyVar vis
-> (TidyEnv, TyVarBndr TyVar vis)
@@ -2820,7 +2827,7 @@ tidyCos env = map (tidyCo env)
-- recursion across a hi-boot file, we don't get the CPR property
-- and these functions allocate a tremendous amount of rubbish.
-- It's not critical (because typeSize is really only used in
--- debug mode, but I tripped over and example (T5642) in which
+-- debug mode, but I tripped over an example (T5642) in which
-- typeSize was one of the biggest single allocators in all of GHC.
-- And it's easy to fix, so I did.
diff --git a/compiler/types/Type.hs b/compiler/types/Type.hs
index 460eb5e5e425..6c01c741b0bb 100644
--- a/compiler/types/Type.hs
+++ b/compiler/types/Type.hs
@@ -187,7 +187,7 @@ module Type (
pprTheta, pprThetaArrowTy, pprClassPred,
pprKind, pprParendKind, pprSourceTyCon,
TyPrec(..), maybeParen,
- pprTyVar, pprTyVars, pprTcAppTy, pprPrefixApp, pprArrowChain,
+ pprTyVar, pprTyVars, pprPrefixApp, pprArrowChain,
-- * Tidying type related things up for printing
tidyType, tidyTypes,
diff --git a/compiler/types/Type.hs-boot b/compiler/types/Type.hs-boot
index 560c251f1bd9..e9cc7863d894 100644
--- a/compiler/types/Type.hs-boot
+++ b/compiler/types/Type.hs-boot
@@ -22,5 +22,5 @@ partitionInvisibles :: TyCon -> (a -> Type) -> [a] -> ([a], [a])
coreView :: Type -> Maybe Type
tyCoVarsOfTypesWellScoped :: [Type] -> [TyVar]
-
+tyCoVarsOfTypeWellScoped :: Type -> [TyVar]
splitTyConApp_maybe :: HasDebugCallStack => Type -> Maybe (TyCon, [Type])
diff --git a/testsuite/tests/deriving/should_fail/T7148.stderr b/testsuite/tests/deriving/should_fail/T7148.stderr
index da07d4f49d86..f8e5055b125e 100644
--- a/testsuite/tests/deriving/should_fail/T7148.stderr
+++ b/testsuite/tests/deriving/should_fail/T7148.stderr
@@ -2,8 +2,8 @@
T7148.hs:27:40: error:
• Couldn't match type ‘b’ with ‘Tagged a b’
arising from the coercion of the method ‘iso2’
- from type ‘forall b. SameType b () -> SameType b b’
- to type ‘forall b. SameType b () -> SameType b (Tagged a b)’
+ from type ‘forall b1. SameType b1 () -> SameType b1 b’
+ to type ‘forall b1. SameType b1 () -> SameType b1 (Tagged a b)’
‘b’ is a rigid type variable bound by
the deriving clause for ‘IsoUnit (Tagged a b)’ at T7148.hs:27:40-46
• When deriving the instance for (IsoUnit (Tagged a b))
@@ -11,8 +11,8 @@ T7148.hs:27:40: error:
T7148.hs:27:40: error:
• Couldn't match type ‘b’ with ‘Tagged a b’
arising from the coercion of the method ‘iso1’
- from type ‘forall b. SameType () b -> SameType b b’
- to type ‘forall b. SameType () b -> SameType (Tagged a b) b’
+ from type ‘forall b1. SameType () b1 -> SameType b b1’
+ to type ‘forall b1. SameType () b1 -> SameType (Tagged a b) b1’
‘b’ is a rigid type variable bound by
the deriving clause for ‘IsoUnit (Tagged a b)’ at T7148.hs:27:40-46
• When deriving the instance for (IsoUnit (Tagged a b))
diff --git a/testsuite/tests/th/T8761.stderr b/testsuite/tests/th/T8761.stderr
index 86f175631b9b..bb0147572217 100644
--- a/testsuite/tests/th/T8761.stderr
+++ b/testsuite/tests/th/T8761.stderr
@@ -81,14 +81,14 @@ T8761.hs:(71,1)-(105,39): Splicing declarations
pattern Pur :: forall a. (Num a, Eq a) => a -> [a]
pattern Pur x <- [x, 1]
pattern Purp ::
- forall a b. (Num a, Eq a) => Show b => a -> b -> ([a], UnivProv b)
+ forall a b. (Num a, Eq a) => Show b => a -> b -> ([a], UnivProv b)
pattern Purp x y <- ([x, 1], MkUnivProv y)
pattern Pure ::
forall a. (Num a, Eq a) => forall b. a -> b -> ([a], Ex)
pattern Pure x y <- ([x, 1], MkEx y)
pattern Purep ::
forall a.
- (Num a, Eq a) => forall b. Show b => a -> b -> ([a], ExProv)
+ (Num a, Eq a) => forall b. Show b => a -> b -> ([a], ExProv)
pattern Purep x y <- ([x, 1], MkExProv y)
pattern Pep :: () => forall a. Show a => a -> ExProv
pattern Pep x <- MkExProv x
@@ -116,44 +116,43 @@ T8761.hs:(71,1)-(105,39): Splicing declarations
pattern Pure x y <- ([x, 1], MkEx y)
pattern Purep ::
forall a.
- (Num a, Eq a) => forall b. Show b => a -> b -> ([a], ExProv)
+ (Num a, Eq a) => forall b. Show b => a -> b -> ([a], ExProv)
pattern Purep x y <- ([x, 1], MkExProv y)
pattern Pep :: () => forall a. Show a => a -> ExProv
pattern Pep x <- MkExProv x
pattern Pup :: forall a. () => Show a => a -> UnivProv a
pattern Pup x <- MkUnivProv x
pattern Puep ::
- forall a. () => forall b. Show b => a -> b -> (ExProv, a)
+ forall a. () => forall b. Show b => a -> b -> (ExProv, a)
pattern Puep x y <- (MkExProv y, x)
pattern T8761.P :: GHC.Types.Bool
-pattern T8761.Pe :: () => forall (a0_0 :: *) . a0_0 -> T8761.Ex
-pattern T8761.Pu :: forall (a0_0 :: *) . a0_0 -> a0_0
-pattern T8761.Pue :: forall (a0_0 :: *) . () => forall (b0_1 :: *) .
- a0_0 -> b0_1 -> (a0_0, T8761.Ex)
-pattern T8761.Pur :: forall (a0_0 :: *) . (GHC.Num.Num a0_0,
- GHC.Classes.Eq a0_0) =>
- a0_0 -> [a0_0]
-pattern T8761.Purp :: forall (a0_0 :: *) (b0_1 :: *) . (GHC.Num.Num a0_0,
- GHC.Classes.Eq a0_0) =>
- GHC.Show.Show b0_1 => a0_0 -> b0_1 -> ([a0_0], T8761.UnivProv b0_1)
-pattern T8761.Pure :: forall (a0_0 :: *) . (GHC.Num.Num a0_0,
- GHC.Classes.Eq a0_0) =>
- forall (b0_1 :: *) . a0_0 -> b0_1 -> ([a0_0], T8761.Ex)
-pattern T8761.Purep :: forall (a0_0 :: *) . (GHC.Num.Num a0_0,
- GHC.Classes.Eq a0_0) =>
- forall (b0_1 :: *) . GHC.Show.Show b0_1 =>
- a0_0 -> b0_1 -> ([a0_0], T8761.ExProv)
-pattern T8761.Pep :: () => forall (a0_0 :: *) . GHC.Show.Show a0_0 =>
- a0_0 -> T8761.ExProv
-pattern T8761.Pup :: forall (a0_0 :: *) . () => GHC.Show.Show a0_0 =>
- a0_0 -> T8761.UnivProv a0_0
-pattern T8761.Puep :: forall (a0_0 :: *) . () => forall (b0_1 :: *) . GHC.Show.Show b0_1 =>
- a0_0 -> b0_1 -> (T8761.ExProv, a0_0)
+pattern T8761.Pe :: () => forall (a_0 :: *) . a_0 -> T8761.Ex
+pattern T8761.Pu :: forall (a_0 :: *) . a_0 -> a_0
+pattern T8761.Pue :: forall (a_0 :: *) . () => forall (b_1 :: *) .
+ a_0 -> b_1 -> (a_0, T8761.Ex)
+pattern T8761.Pur :: forall (a_0 :: *) . (GHC.Num.Num a_0,
+ GHC.Classes.Eq a_0) =>
+ a_0 -> [a_0]
+pattern T8761.Purp :: forall (a_0 :: *) (b_1 :: *) . (GHC.Num.Num a_0,
+ GHC.Classes.Eq a_0) =>
+ GHC.Show.Show b_1 => a_0 -> b_1 -> ([a_0], T8761.UnivProv b_1)
+pattern T8761.Pure :: forall (a_0 :: *) . (GHC.Num.Num a_0,
+ GHC.Classes.Eq a_0) =>
+ forall (b_1 :: *) . a_0 -> b_1 -> ([a_0], T8761.Ex)
+pattern T8761.Purep :: forall (a_0 :: *) . (GHC.Num.Num a_0,
+ GHC.Classes.Eq a_0) =>
+ forall (b_1 :: *) . GHC.Show.Show b_1 =>
+ a_0 -> b_1 -> ([a_0], T8761.ExProv)
+pattern T8761.Pep :: () => forall (a_0 :: *) . GHC.Show.Show a_0 =>
+ a_0 -> T8761.ExProv
+pattern T8761.Pup :: forall (a_0 :: *) . () => GHC.Show.Show a_0 =>
+ a_0 -> T8761.UnivProv a_0
+pattern T8761.Puep :: forall (a_0 :: *) . () => forall (b_1 :: *) . GHC.Show.Show b_1 =>
+ a_0 -> b_1 -> (T8761.ExProv, a_0)
T8761.hs:(108,1)-(117,25): Splicing declarations
do infos <- mapM
reify
- ['P, 'Pe, 'Pu, 'Pue, 'Pur, 'Purp, 'Pure, 'Purep, 'Pep, 'Pup,
- 'Puep]
+ ['P, 'Pe, 'Pu, 'Pue, 'Pur, 'Purp, 'Pure, 'Purep, 'Pep, 'Pup, 'Puep]
mapM_ (runIO . hPutStrLn stderr . pprint) infos
[d| theAnswerIs = 42 |]
======>
diff --git a/testsuite/tests/typecheck/should_fail/T12785b.stderr b/testsuite/tests/typecheck/should_fail/T12785b.stderr
index 0290cfe4dd03..1b1d1bc569e8 100644
--- a/testsuite/tests/typecheck/should_fail/T12785b.stderr
+++ b/testsuite/tests/typecheck/should_fail/T12785b.stderr
@@ -1,8 +1,8 @@
T12785b.hs:29:63: error:
- • Could not deduce: Payload ('S n1) (Payload n1 s1) ~ s
+ • Could not deduce: Payload ('S n) (Payload n s1) ~ s
arising from a use of ‘SBranchX’
- from the context: m1 ~ 'S n1
+ from the context: m ~ 'S n
bound by a pattern with constructor:
Branch :: forall a (n :: Peano).
a -> HTree n (HTree ('S n) a) -> HTree ('S n) a,
@@ -15,12 +15,11 @@ T12785b.hs:29:63: error:
= Hide $ a `SBranchX` tr
• Relevant bindings include
tr :: STree
- n1
- (HTree ('S n1) (HTree ('S ('S n1)) a))
- (STree ('S n1) (HTree ('S ('S n1)) a) (STree ('S ('S n1)) a f))
+ n
+ (HTree ('S n) (HTree ('S ('S n)) a))
+ (STree ('S n) (HTree ('S ('S n)) a) (STree ('S ('S n)) a f))
s1
(bound at T12785b.hs:29:49)
- a :: STree ('S m1) a f s (bound at T12785b.hs:29:12)
- nest :: HTree m1 (Hidden ('S m1) f)
- -> Hidden m1 (STree ('S m1) a f)
+ a :: STree ('S m) a f s (bound at T12785b.hs:29:12)
+ nest :: HTree m (Hidden ('S m) f) -> Hidden m (STree ('S m) a f)
(bound at T12785b.hs:27:1)
--
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