diff options
Diffstat (limited to 'compiler/GHC/Tc/Utils/Zonk.hs')
| -rw-r--r-- | compiler/GHC/Tc/Utils/Zonk.hs | 22 |
1 files changed, 15 insertions, 7 deletions
diff --git a/compiler/GHC/Tc/Utils/Zonk.hs b/compiler/GHC/Tc/Utils/Zonk.hs index cc09edd778..805d6a483d 100644 --- a/compiler/GHC/Tc/Utils/Zonk.hs +++ b/compiler/GHC/Tc/Utils/Zonk.hs @@ -37,7 +37,7 @@ module GHC.Tc.Utils.Zonk ( zonkCoToCo, zonkEvBinds, zonkTcEvBinds, zonkTcMethInfoToMethInfoX, - lookupTyVarOcc + lookupTyVarX ) where import GHC.Prelude @@ -1776,7 +1776,7 @@ change. But in some cases it makes a HUGE difference: see test T9198 and #19668. So yes, it seems worth it. -} -zonkTyVarOcc :: ZonkEnv -> TyVar -> TcM TcType +zonkTyVarOcc :: ZonkEnv -> TcTyVar -> TcM Type zonkTyVarOcc env@(ZonkEnv { ze_flexi = flexi , ze_tv_env = tv_env , ze_meta_tv_env = mtv_env_ref }) tv @@ -1791,13 +1791,19 @@ zonkTyVarOcc env@(ZonkEnv { ze_flexi = flexi Just ty -> return ty Nothing -> do { mtv_details <- readTcRef ref ; zonk_meta ref mtv_details } } - | otherwise + | otherwise -- This should never really happen; + -- TyVars should not occur in the typechecker = lookup_in_tv_env where lookup_in_tv_env -- Look up in the env just as we do for Ids = case lookupVarEnv tv_env tv of - Nothing -> mkTyVarTy <$> updateTyVarKindM (zonkTcTypeToTypeX env) tv + Nothing -> -- TyVar/SkolemTv/RuntimeUnk that isn't in the ZonkEnv + -- This can happen for RuntimeUnk variables (which + -- should stay as RuntimeUnk), but I think it should + -- not happen for SkolemTv. + mkTyVarTy <$> updateTyVarKindM (zonkTcTypeToTypeX env) tv + Just tv' -> return (mkTyVarTy tv') zonk_meta ref Flexi @@ -1814,9 +1820,11 @@ zonkTyVarOcc env@(ZonkEnv { ze_flexi = flexi = do { updTcRef mtv_env_ref (\env -> extendVarEnv env tv ty) ; return ty } -lookupTyVarOcc :: ZonkEnv -> TcTyVar -> Maybe TyVar -lookupTyVarOcc (ZonkEnv { ze_tv_env = tv_env }) tv - = lookupVarEnv tv_env tv +lookupTyVarX :: ZonkEnv -> TcTyVar -> TyVar +lookupTyVarX (ZonkEnv { ze_tv_env = tv_env }) tv + = case lookupVarEnv tv_env tv of + Just tv -> tv + Nothing -> pprPanic "lookupTyVarOcc" (ppr tv $$ ppr tv_env) commitFlexi :: ZonkFlexi -> TcTyVar -> Kind -> TcM Type -- Only monadic so we can do tc-tracing |