diff options
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/main/DynFlags.hs | 3 | ||||
| -rw-r--r-- | compiler/typecheck/TcErrors.hs | 55 |
2 files changed, 37 insertions, 21 deletions
diff --git a/compiler/main/DynFlags.hs b/compiler/main/DynFlags.hs index cf5091431a..23a5fedda5 100644 --- a/compiler/main/DynFlags.hs +++ b/compiler/main/DynFlags.hs @@ -524,6 +524,7 @@ data WarningFlag = | Opt_WarnMissingExportedSigs | Opt_WarnUntickedPromotedConstructors | Opt_WarnDerivingTypeable + | Opt_WarnDeferredTypeErrors deriving (Eq, Show, Enum) data Language = Haskell98 | Haskell2010 @@ -2848,6 +2849,7 @@ fWarningFlags = [ flagSpec' "warn-amp" Opt_WarnAMP (\_ -> deprecate "it has no effect, and will be removed in GHC 7.12"), flagSpec "warn-auto-orphans" Opt_WarnAutoOrphans, + flagSpec "warn-deferred-type-errors" Opt_WarnDeferredTypeErrors, flagSpec "warn-deprecations" Opt_WarnWarningsDeprecations, flagSpec "warn-deprecated-flags" Opt_WarnDeprecatedFlags, flagSpec "warn-deriving-typeable" Opt_WarnDerivingTypeable, @@ -3344,6 +3346,7 @@ standardWarnings -- see Note [Documenting warning flags] = [ Opt_WarnOverlappingPatterns, Opt_WarnWarningsDeprecations, Opt_WarnDeprecatedFlags, + Opt_WarnDeferredTypeErrors, Opt_WarnTypedHoles, Opt_WarnPartialTypeSignatures, Opt_WarnUnrecognisedPragmas, diff --git a/compiler/typecheck/TcErrors.hs b/compiler/typecheck/TcErrors.hs index 032af20b16..9809db83f5 100644 --- a/compiler/typecheck/TcErrors.hs +++ b/compiler/typecheck/TcErrors.hs @@ -101,8 +101,12 @@ compilation. The errors are turned into warnings in `reportUnsolved`. -- deferred run-time errors if `-fdefer-type-errors` is on. reportUnsolved :: WantedConstraints -> TcM (Bag EvBind) reportUnsolved wanted - = do { binds_var <- newTcEvBinds - ; defer_errs <- goptM Opt_DeferTypeErrors + = do { binds_var <- newTcEvBinds + ; defer_errors <- goptM Opt_DeferTypeErrors + ; warn_errors <- woptM Opt_WarnDeferredTypeErrors -- implement #10283 + ; let type_errors | not defer_errors = TypeError + | warn_errors = TypeWarn + | otherwise = TypeDefer ; defer_holes <- goptM Opt_DeferTypedHoles ; warn_holes <- woptM Opt_WarnTypedHoles @@ -116,30 +120,30 @@ reportUnsolved wanted | warn_partial_sigs = HoleWarn | otherwise = HoleDefer - ; report_unsolved (Just binds_var) False defer_errs expr_holes type_holes wanted + ; report_unsolved (Just binds_var) False type_errors expr_holes type_holes wanted ; getTcEvBinds binds_var } -- | Report *all* unsolved goals as errors, even if -fdefer-type-errors is on -- See Note [Deferring coercion errors to runtime] reportAllUnsolved :: WantedConstraints -> TcM () reportAllUnsolved wanted - = report_unsolved Nothing False False HoleError HoleError wanted + = report_unsolved Nothing False TypeError HoleError HoleError wanted -- | Report all unsolved goals as warnings (but without deferring any errors to -- run-time). See Note [Safe Haskell Overlapping Instances Implementation] in -- TcSimplify warnAllUnsolved :: WantedConstraints -> TcM () warnAllUnsolved wanted - = report_unsolved Nothing True False HoleWarn HoleWarn wanted + = report_unsolved Nothing True TypeWarn HoleWarn HoleWarn wanted -- | Report unsolved goals as errors or warnings. report_unsolved :: Maybe EvBindsVar -- cec_binds -> Bool -- Errors as warnings - -> Bool -- cec_defer_type_errors + -> TypeErrorChoice -- Deferred type errors -> HoleChoice -- Expression holes -> HoleChoice -- Type holes -> WantedConstraints -> TcM () -report_unsolved mb_binds_var err_as_warn defer_errs expr_holes type_holes wanted +report_unsolved mb_binds_var err_as_warn type_errors expr_holes type_holes wanted | isEmptyWC wanted = return () | otherwise @@ -159,7 +163,7 @@ report_unsolved mb_binds_var err_as_warn defer_errs expr_holes type_holes wanted ; warn_redundant <- woptM Opt_WarnRedundantConstraints ; let err_ctxt = CEC { cec_encl = [] , cec_tidy = tidy_env - , cec_defer_type_errors = defer_errs + , cec_defer_type_errors = type_errors , cec_errors_as_warns = err_as_warn , cec_expr_holes = expr_holes , cec_type_holes = type_holes @@ -174,6 +178,11 @@ report_unsolved mb_binds_var err_as_warn defer_errs expr_holes type_holes wanted -- Internal functions -------------------------------------------- +data TypeErrorChoice -- What to do for type errors found by the type checker + = TypeError -- A type error aborts compilation with an error message + | TypeWarn -- A type error is deferred to runtime, plus a compile-time warning + | TypeDefer -- A type error is deferred to runtime; no error or warning at compile time + data HoleChoice = HoleError -- A hole is a compile-time error | HoleWarn -- Defer to runtime, emit a compile-time warning @@ -194,9 +203,8 @@ data ReportErrCtxt -- (except for Holes, which are -- controlled by cec_type_holes and -- cec_expr_holes) - , cec_defer_type_errors :: Bool -- True <=> -fdefer-type-errors - -- Defer type errors until runtime - -- Irrelevant if cec_binds = Nothing + , cec_defer_type_errors :: TypeErrorChoice -- Defer type errors until runtime + -- Irrelevant if cec_binds = Nothing , cec_expr_holes :: HoleChoice -- Holes in expressions , cec_type_holes :: HoleChoice -- Holes in types @@ -472,13 +480,14 @@ maybeReportHoleError ctxt ct err maybeReportError :: ReportErrCtxt -> ErrMsg -> TcM () -- Report the error and/or make a deferred binding for it maybeReportError ctxt err - -- See Note [Always warn with -fdefer-type-errors] - | cec_defer_type_errors ctxt || cec_errors_as_warns ctxt + | cec_errors_as_warns ctxt = reportWarning err - | cec_suppress ctxt - = return () | otherwise - = reportError err + = case cec_defer_type_errors ctxt of + TypeDefer -> return () + TypeWarn -> reportWarning err + -- handle case when suppress is on like in the original code + TypeError -> if cec_suppress ctxt then return () else reportError err addDeferredBinding :: ReportErrCtxt -> ErrMsg -> Ct -> TcM () -- See Note [Deferring coercion errors to runtime] @@ -509,11 +518,13 @@ maybeAddDeferredHoleBinding ctxt err ct = return () maybeAddDeferredBinding :: ReportErrCtxt -> ErrMsg -> Ct -> TcM () -maybeAddDeferredBinding ctxt err ct - | cec_defer_type_errors ctxt - = addDeferredBinding ctxt err ct - | otherwise - = return () +maybeAddDeferredBinding ctxt err ct = + case cec_defer_type_errors ctxt of + TypeDefer -> deferred + TypeWarn -> deferred + TypeError -> return () + where + deferred = addDeferredBinding ctxt err ct tryReporters :: ReportErrCtxt -> [ReporterSpec] -> [Ct] -> TcM (ReportErrCtxt, [Ct]) -- Use the first reporter in the list whose predicate says True @@ -611,6 +622,8 @@ To be consistent, we should also report multiple warnings from a single location in mkGroupReporter, when -fdefer-type-errors is on. But that is perhaps a bit *over*-consistent! Again, an easy choice to change. +With #10283, you can now opt out of deferred type error warnings. + Note [Do not report derived but soluble errors] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |