diff options
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/main/DynFlags.hs | 2 | ||||
| -rw-r--r-- | compiler/rename/RnSource.hs | 25 | ||||
| -rw-r--r-- | compiler/typecheck/TcDerivUtils.hs | 2 |
3 files changed, 28 insertions, 1 deletions
diff --git a/compiler/main/DynFlags.hs b/compiler/main/DynFlags.hs index 02ad366338..7296809155 100644 --- a/compiler/main/DynFlags.hs +++ b/compiler/main/DynFlags.hs @@ -834,6 +834,7 @@ data WarningFlag = | Opt_WarnStarBinder -- Since 8.6 | Opt_WarnImplicitKindVars -- Since 8.6 | Opt_WarnSpaceAfterBang + | Opt_WarnMissingDerivingStrategies -- Since 8.8 deriving (Eq, Show, Enum) data Language = Haskell98 | Haskell2010 @@ -4022,6 +4023,7 @@ wWarningFlagsDeps = [ flagSpec "wrong-do-bind" Opt_WarnWrongDoBind, flagSpec "missing-pattern-synonym-signatures" Opt_WarnMissingPatternSynonymSignatures, + flagSpec "missing-deriving-strategies" Opt_WarnMissingDerivingStrategies, flagSpec "simplifiable-class-constraints" Opt_WarnSimplifiableClassConstraints, flagSpec "missing-home-modules" Opt_WarnMissingHomeModules, flagSpec "unrecognised-warning-flags" Opt_WarnUnrecognisedWarningFlags, diff --git a/compiler/rename/RnSource.hs b/compiler/rename/RnSource.hs index c76eb31abc..e3e852984e 100644 --- a/compiler/rename/RnSource.hs +++ b/compiler/rename/RnSource.hs @@ -1009,6 +1009,7 @@ rnSrcDerivDecl (DerivDecl _ ty mds overlap) <- rnLDerivStrategy DerivDeclCtx mds $ \strat_tvs ppr_via_ty -> rnAndReportFloatingViaTvs strat_tvs loc ppr_via_ty "instance" $ rnHsSigWcType BindUnlessForall DerivDeclCtx ty + ; warnNoDerivStrat mds' loc ; return (DerivDecl noExt ty' mds' overlap, fvs) } where loc = getLoc $ hsib_body $ hswc_body ty @@ -1710,6 +1711,29 @@ rnDataDefn doc (HsDataDefn { dd_ND = new_or_data, dd_cType = cType ; return (cL loc ds', fvs) } rnDataDefn _ (XHsDataDefn _) = panic "rnDataDefn" +warnNoDerivStrat :: Maybe (LDerivStrategy GhcRn) + -> SrcSpan + -> RnM () +warnNoDerivStrat mds loc + = do { dyn_flags <- getDynFlags + ; when (wopt Opt_WarnMissingDerivingStrategies dyn_flags) $ + case mds of + Nothing -> addWarnAt + (Reason Opt_WarnMissingDerivingStrategies) + loc + (if xopt LangExt.DerivingStrategies dyn_flags + then no_strat_warning + else no_strat_warning $+$ deriv_strat_nenabled + ) + _ -> pure () + } + where + no_strat_warning :: SDoc + no_strat_warning = text "No deriving strategy specified. Did you want stock" + <> text ", newtype, or anyclass?" + deriv_strat_nenabled :: SDoc + deriv_strat_nenabled = text "Use DerivingStrategies to specify a strategy." + rnLHsDerivingClause :: HsDocContext -> LHsDerivingClause GhcPs -> RnM (LHsDerivingClause GhcRn, FreeVars) rnLHsDerivingClause doc @@ -1720,6 +1744,7 @@ rnLHsDerivingClause doc = do { (dcs', dct', fvs) <- rnLDerivStrategy doc dcs $ \strat_tvs ppr_via_ty -> mapFvRn (rn_deriv_ty strat_tvs ppr_via_ty) dct + ; warnNoDerivStrat dcs' loc ; pure ( cL loc (HsDerivingClause { deriv_clause_ext = noExt , deriv_clause_strategy = dcs' , deriv_clause_tys = cL loc' dct' }) diff --git a/compiler/typecheck/TcDerivUtils.hs b/compiler/typecheck/TcDerivUtils.hs index 86205de5fd..5f48e5f003 100644 --- a/compiler/typecheck/TcDerivUtils.hs +++ b/compiler/typecheck/TcDerivUtils.hs @@ -62,7 +62,7 @@ import ListSetOps (assocMaybe) -- is a simple reader around 'TcRn'. type DerivM = ReaderT DerivEnv TcRn --- | Is GHC processing a stanalone deriving declaration? +-- | Is GHC processing a standalone deriving declaration? isStandaloneDeriv :: DerivM Bool isStandaloneDeriv = asks (go . denv_ctxt) where |