reportFlat :: ReportErrCtxt -> [PredType] -> CtOrigin -> TcM ()
reportFlat ctxt flats origin
= do { unless (null dicts) $ reportDictErrs ctxt dicts origin
- ; unless (null eqs) $ reportEqErrs ctxt eqs
+ ; unless (null eqs) $ reportEqErrs ctxt eqs origin
; unless (null ips) $ reportIPErrs ctxt ips origin
; ASSERT( null others ) return () }
where
%************************************************************************
\begin{code}
-reportEqErrs :: ReportErrCtxt -> [PredType] -> TcM ()
-reportEqErrs ctxt eqs
+reportEqErrs :: ReportErrCtxt -> [PredType] -> CtOrigin -> TcM ()
+reportEqErrs ctxt eqs orig
= mapM_ report_one eqs
where
- report_one (EqPred ty1 ty2) = reportEqErr ctxt ty1 ty2
- report_one pred = pprPanic "reportEqErrs" (ppr pred)
+ env0 = cec_tidy ctxt
+ report_one (EqPred ty1 ty2)
+ = getWantedEqExtra emptyTvSubst env0 orig ty1 ty2 $ \ env1 extra ->
+ let ctxt' = ctxt { cec_tidy = env1
+ , cec_extra = cec_extra ctxt $$ extra }
+ in reportEqErr ctxt' ty1 ty2
+ report_one pred
+ = pprPanic "reportEqErrs" (ppr pred)
reportEqErr :: ReportErrCtxt -> TcType -> TcType -> TcM ()
reportEqErr ctxt ty1 ty2
monomorphism_fix dflags
= ptext (sLit "Probable fix:") <+> vcat
[ptext (sLit "give these definition(s) an explicit type signature"),
- if dopt Opt_MonomorphismRestriction dflags
+ if xopt Opt_MonomorphismRestriction dflags
then ptext (sLit "or use -XNoMonomorphismRestriction")
else empty] -- Only suggest adding "-XNoMonomorphismRestriction"
-- if it is not already set!
-- in which case that's the error to report. So we set things
-- up to call reportEqErr, which does the business properly
kindErrorTcS fl ty1 ty2
- = wrapErrTcS $
- setCtFlavorLoc fl $
- do { env0 <- tcInitTidyEnv
- ; let (env1, ty1') = tidyOpenType env0 ty1
+ = wrapEqErrTcS fl ty1 ty2 $ \ env0 extra ->
+ do { let (env1, ty1') = tidyOpenType env0 ty1
(env2, ty2') = tidyOpenType env1 ty2
ctxt = CEC { cec_encl = []
- , cec_extra = empty
+ , cec_extra = extra
, cec_tidy = env2 }
; reportEqErr ctxt ty1' ty2' }
misMatchErrorTcS :: CtFlavor -> TcType -> TcType -> TcS a
misMatchErrorTcS fl ty1 ty2
- = wrapErrTcS $
- setCtFlavorLocNoEq fl $ -- Don't add the "When matching t1 with t2"
- -- part, because it duplciates what we say now
- do { env0 <- tcInitTidyEnv
- ; let (env1, ty1') = tidyOpenType env0 ty1
+ = wrapEqErrTcS fl ty1 ty2 $ \ env0 extra ->
+ do { let (env1, ty1') = tidyOpenType env0 ty1
(env2, ty2') = tidyOpenType env1 ty2
(env3, msg) = misMatchMsgWithExtras env2 ty1' ty2'
- ; failWithTcM (env3, inaccessible_msg $$ msg) }
+ ; failWithTcM (env3, inaccessible_msg $$ msg $$ extra) }
where
inaccessible_msg
= case fl of
occursCheckErrorTcS :: CtFlavor -> TcTyVar -> TcType -> TcS a
occursCheckErrorTcS fl tv ty
- = wrapErrTcS $
- setCtFlavorLoc fl $
- do { env0 <- tcInitTidyEnv
- ; let (env1, tv') = tidyOpenTyVar env0 tv
+ = wrapEqErrTcS fl (mkTyVarTy tv) ty $ \ env0 extra2 ->
+ do { let (env1, tv') = tidyOpenTyVar env0 tv
(env2, ty') = tidyOpenType env1 ty
- extra = sep [ppr tv', char '=', ppr ty']
- ; failWithTcM (env2, hang msg 2 extra) }
+ extra1 = sep [ppr tv', char '=', ppr ty']
+ ; failWithTcM (env2, hang msg 2 (extra1 $$ extra2)) }
where
msg = text $ "Occurs check: cannot construct the infinite type:"
%************************************************************************
\begin{code}
-setCtFlavorLocNoEq :: CtFlavor -> TcM a -> TcM a
-setCtFlavorLocNoEq (Wanted loc) thing = setCtLoc loc thing
-setCtFlavorLocNoEq (Derived loc) thing = setCtLoc loc thing
-setCtFlavorLocNoEq (Given loc) thing = setCtLoc loc thing
-
setCtFlavorLoc :: CtFlavor -> TcM a -> TcM a
-setCtFlavorLoc (Wanted loc) thing = setWantedLoc loc thing
-setCtFlavorLoc (Derived loc) thing = setWantedLoc loc thing
-setCtFlavorLoc (Given loc) thing = setGivenLoc loc thing
-
-setWantedLoc :: WantedLoc -> TcM a -> TcM a
-setWantedLoc loc thing_inside
- = setCtLoc loc $
- add_origin (ctLocOrigin loc) $
- thing_inside
- where
- add_origin (TypeEqOrigin item) = addErrCtxtM (unifyCtxt item)
- add_origin orig = addErrCtxt (ptext (sLit "At") <+> ppr orig)
-
-setGivenLoc :: GivenLoc -> TcM a -> TcM a
-setGivenLoc loc thing_inside
- = setCtLoc loc $
- add_origin (ctLocOrigin loc) $
- thing_inside
- where
- add_origin skol = addErrCtxt (ptext (sLit "In") <+> pprSkolInfo skol)
+setCtFlavorLoc (Wanted loc) thing = setCtLoc loc thing
+setCtFlavorLoc (Derived loc) thing = setCtLoc loc thing
+setCtFlavorLoc (Given loc) thing = setCtLoc loc thing
+
+wrapEqErrTcS :: CtFlavor -> TcType -> TcType
+ -> (TidyEnv -> SDoc -> TcM a)
+ -> TcS a
+wrapEqErrTcS fl ty1 ty2 thing_inside
+ = do { ty_binds_var <- getTcSTyBinds
+ ; wrapErrTcS $ setCtFlavorLoc fl $
+ do { env0 <- tcInitTidyEnv
+ ; ty_binds_bag <- readTcRef ty_binds_var
+ ; let subst = mkOpenTvSubst (mkVarEnv (bagToList ty_binds_bag))
+ ; case fl of
+ Wanted loc -> getWantedEqExtra subst env0 (ctLocOrigin loc) ty1 ty2 thing_inside
+ Derived loc -> getWantedEqExtra subst env0 (ctLocOrigin loc) ty1 ty2 thing_inside
+ Given {} -> thing_inside env0 empty -- We could print more info, but it
+ -- seems to be coming out already
+ } }
+
+getWantedEqExtra :: TvSubst -> TidyEnv -> CtOrigin -> TcType -> TcType
+ -> (TidyEnv -> SDoc -> TcM a)
+ -> TcM a
+getWantedEqExtra subst env0 (TypeEqOrigin item) ty1 ty2 thing_inside
+ -- If the types in the error message are the same
+ -- as the types we are unifying (remember to zonk the latter)
+ -- don't add the extra expected/actual message
+ --
+ -- The complication is that the types in the TypeEqOrigin must
+ -- (a) be zonked
+ -- (b) have any TcS-monad pending equalities applied to them
+ -- (hence the passed-in substitution)
+ = do { act0 <- zonkTcType (uo_actual item)
+ ; exp0 <- zonkTcType (uo_expected item)
+ ; let act1 = substTy subst act0
+ exp1 = substTy subst exp0
+ (env1, exp2) = tidyOpenType env0 exp1
+ (env2, act2) = tidyOpenType env1 act1
+ ; if (act1 `tcEqType` ty1 && exp1 `tcEqType` ty2)
+ || (exp1 `tcEqType` ty1 && act1 `tcEqType` ty2)
+ then
+ thing_inside env0 empty
+ else
+ thing_inside env2 (mkExpectedActualMsg act2 exp2) }
+
+getWantedEqExtra _ env0 orig _ _ thing_inside
+ = thing_inside env0 (pprArising orig)
\end{code}
projects / ghc-hetmet.git / blobdiff