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| author | Simon Peyton Jones <simonpj@microsoft.com> | 2018-01-10 16:46:55 +0000 |
|---|---|---|
| committer | Simon Peyton Jones <simonpj@microsoft.com> | 2018-01-10 16:48:59 +0000 |
| commit | f3f90a079179e085295ee7edd2dda6505799370c (patch) | |
| tree | 59a229f36f80d33add0aa70f87dbf1da1ce196f7 | |
| parent | dbdf77d92c9cd0bbb269137de0bf8754573cdc1e (diff) | |
| download | haskell-f3f90a079179e085295ee7edd2dda6505799370c.tar.gz | |
Fix previous patch
This recent patch
commit 1577908f2a9db0fcf6f749d40dd75481015f5497
Author: Simon Peyton Jones <simonpj@microsoft.com>
Date: Tue Jan 9 16:20:46 2018 +0000
Fix two more bugs in partial signatures
These were shown up by Trac #14643
failed validation for typecheck/should_run/T10846
(Reported in Trac #14658.)
The fix is simple.
| -rw-r--r-- | compiler/typecheck/TcSimplify.hs | 29 |
1 files changed, 17 insertions, 12 deletions
diff --git a/compiler/typecheck/TcSimplify.hs b/compiler/typecheck/TcSimplify.hs index 0048c090a0..72c9af94b8 100644 --- a/compiler/typecheck/TcSimplify.hs +++ b/compiler/typecheck/TcSimplify.hs @@ -878,20 +878,25 @@ decideQuantification infer_mode rhs_tclvl name_taus psigs candidates -- predicates to actually quantify over -- NB: decideQuantifiedTyVars turned some meta tyvars -- into quantified skolems, so we have to zonk again - ; let psig_theta = concatMap sig_inst_theta psigs - ; all_candidates <- TcM.zonkTcTypes (psig_theta ++ candidates) - ; let theta = pickQuantifiablePreds (mkVarSet qtvs) $ - mkMinimalBySCs id $ -- See Note [Minimize by Superclasses] - all_candidates + ; candidates <- TcM.zonkTcTypes candidates + ; psig_theta <- TcM.zonkTcTypes (concatMap sig_inst_theta psigs) + ; let quantifiable_candidates + = pickQuantifiablePreds (mkVarSet qtvs) candidates + -- NB: do /not/ run pickQuantifieablePreds over psig_theta, + -- because we always want to quantify over psig_theta, and not + -- drop any of them; e.g. CallStack constraints. c.f Trac #14658 + + theta = mkMinimalBySCs id $ -- See Note [Minimize by Superclasses] + (psig_theta ++ quantifiable_candidates) ; traceTc "decideQuantification" - (vcat [ text "infer_mode:" <+> ppr infer_mode - , text "candidates:" <+> ppr candidates - , text "all_candidates:" <+> ppr all_candidates - , text "mono_tvs:" <+> ppr mono_tvs - , text "co_vars:" <+> ppr co_vars - , text "qtvs:" <+> ppr qtvs - , text "theta:" <+> ppr theta ]) + (vcat [ text "infer_mode:" <+> ppr infer_mode + , text "candidates:" <+> ppr candidates + , text "psig_theta:" <+> ppr psig_theta + , text "mono_tvs:" <+> ppr mono_tvs + , text "co_vars:" <+> ppr co_vars + , text "qtvs:" <+> ppr qtvs + , text "theta:" <+> ppr theta ]) ; return (qtvs, theta, co_vars) } ------------------ |