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-rw-r--r--compiler/GHC/Driver/Errors.hs16
-rw-r--r--compiler/GHC/Driver/Errors/Ppr.hs60
-rw-r--r--compiler/GHC/Driver/Errors/Types.hs23
-rw-r--r--compiler/GHC/Driver/Main.hs26
-rw-r--r--compiler/GHC/Driver/Make.hs7
-rw-r--r--compiler/GHC/Driver/MakeFile.hs2
-rw-r--r--compiler/GHC/Driver/Pipeline.hs2
-rw-r--r--compiler/GHC/HsToCore/Errors/Ppr.hs2
-rw-r--r--compiler/GHC/HsToCore/Monad.hs4
-rw-r--r--compiler/GHC/Iface/Rename.hs2
-rw-r--r--compiler/GHC/Parser.y1
-rw-r--r--compiler/GHC/Parser/Errors.hs16
-rw-r--r--compiler/GHC/Parser/Errors/Ppr.hs57
-rw-r--r--compiler/GHC/Parser/Header.hs4
-rw-r--r--compiler/GHC/Parser/Lexer.x9
-rw-r--r--compiler/GHC/Parser/PostProcess.hs12
-rw-r--r--compiler/GHC/Tc/Errors/Ppr.hs15
-rw-r--r--compiler/GHC/Tc/Module.hs4
-rw-r--r--compiler/GHC/Tc/Utils/Monad.hs6
-rw-r--r--compiler/GHC/Types/Error.hs43
-rw-r--r--compiler/GHC/Types/Hint.hs130
-rw-r--r--compiler/GHC/Utils/Error.hs1
-rw-r--r--compiler/ghc.cabal.in1
-rw-r--r--testsuite/tests/driver/T12955.stderr8
-rw-r--r--testsuite/tests/parser/should_run/CountAstDeps.stdout3
-rw-r--r--testsuite/tests/parser/should_run/CountParserDeps.stdout3
26 files changed, 314 insertions, 143 deletions
diff --git a/compiler/GHC/Driver/Errors.hs b/compiler/GHC/Driver/Errors.hs
index 7afb0f3b26..f980502f5d 100644
--- a/compiler/GHC/Driver/Errors.hs
+++ b/compiler/GHC/Driver/Errors.hs
@@ -14,7 +14,7 @@ import GHC.Types.SrcLoc
import GHC.Types.SourceError
import GHC.Types.Error
import GHC.Utils.Error
-import GHC.Utils.Outputable ( text, withPprStyle, mkErrStyle )
+import GHC.Utils.Outputable (hang, ppr, ($$), SDocContext, text, withPprStyle, mkErrStyle )
import GHC.Utils.Logger
import qualified GHC.Driver.CmdLine as CmdLine
@@ -23,12 +23,21 @@ printMessages logger dflags msgs
= sequence_ [ let style = mkErrStyle unqual
ctx = initSDocContext dflags style
in putLogMsg logger dflags (MCDiagnostic sev . diagnosticReason $ dia) s $
- withPprStyle style (formatBulleted ctx (diagnosticMessage dia))
+ withPprStyle style (messageWithHints ctx dia)
| MsgEnvelope { errMsgSpan = s,
errMsgDiagnostic = dia,
errMsgSeverity = sev,
errMsgContext = unqual } <- sortMsgBag (Just dflags)
(getMessages msgs) ]
+ where
+ messageWithHints :: Diagnostic a => SDocContext -> a -> SDoc
+ messageWithHints ctx e =
+ let main_msg = formatBulleted ctx $ diagnosticMessage e
+ in case diagnosticHints e of
+ [] -> main_msg
+ [h] -> main_msg $$ hang (text "Suggested fix:") 2 (ppr h)
+ hs -> main_msg $$ hang (text "Suggested fixes:") 2
+ (formatBulleted ctx . mkDecorated . map ppr $ hs)
handleFlagWarnings :: Logger -> DynFlags -> [CmdLine.Warn] -> IO ()
handleFlagWarnings logger dflags warns = do
@@ -37,8 +46,7 @@ handleFlagWarnings logger dflags warns = do
bag = listToBag [ mkPlainMsgEnvelope dflags loc $
GhcDriverMessage $
DriverUnknownMessage $
- mkPlainDiagnostic reason $
- text warn
+ mkPlainDiagnostic reason noHints $ text warn
| CmdLine.Warn reason (L loc warn) <- warns ]
printOrThrowDiagnostics logger dflags (mkMessages bag)
diff --git a/compiler/GHC/Driver/Errors/Ppr.hs b/compiler/GHC/Driver/Errors/Ppr.hs
index 74c3d4bf21..853d83b76b 100644
--- a/compiler/GHC/Driver/Errors/Ppr.hs
+++ b/compiler/GHC/Driver/Errors/Ppr.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE GADTs #-}
{-# LANGUAGE LambdaCase #-}
{-# OPTIONS_GHC -fno-warn-orphans #-} -- instance Diagnostic {DriverMessage, GhcMessage}
@@ -15,6 +16,7 @@ import GHC.Types.Error
import GHC.Unit.Types
import GHC.Utils.Outputable
import GHC.Unit.Module
+import GHC.Types.Hint
--
-- Suggestions
@@ -51,6 +53,18 @@ instance Diagnostic GhcMessage where
GhcUnknownMessage m
-> diagnosticReason m
+ diagnosticHints = \case
+ GhcPsMessage m
+ -> diagnosticHints m
+ GhcTcRnMessage m
+ -> diagnosticHints m
+ GhcDsMessage m
+ -> diagnosticHints m
+ GhcDriverMessage m
+ -> diagnosticHints m
+ GhcUnknownMessage m
+ -> diagnosticHints m
+
instance Diagnostic DriverMessage where
diagnosticMessage = \case
DriverUnknownMessage m
@@ -99,22 +113,8 @@ instance Diagnostic DriverMessage where
$$ text "Saw :" <+> quotes (ppr actual)
$$ text "Expected:" <+> quotes (ppr expected)
- DriverUnexpectedSignature pi_mod_name buildingCabalPackage suggestions
- -> let suggested_instantiated_with =
- hcat (punctuate comma $
- [ ppr k <> text "=" <> ppr v
- | InstantiationSuggestion k v <- suggestions
- ])
- msg = text "Unexpected signature:" <+> quotes (ppr pi_mod_name)
- $$ if buildingCabalPackage == YesBuildingCabalPackage
- then parens (text "Try adding" <+> quotes (ppr pi_mod_name)
- <+> text "to the"
- <+> quotes (text "signatures")
- <+> text "field in your Cabal file.")
- else parens (text "Try passing -instantiated-with=\"" <>
- suggested_instantiated_with <> text "\"" $$
- text "replacing <" <> ppr pi_mod_name <> text "> as necessary.")
- in mkSimpleDecorated msg
+ DriverUnexpectedSignature pi_mod_name _buildingCabalPackage _instantiations
+ -> mkSimpleDecorated $ text "Unexpected signature:" <+> quotes (ppr pi_mod_name)
DriverFileNotFound hsFilePath
-> mkSimpleDecorated (text "Can't find" <+> text hsFilePath)
DriverStaticPointersNotSupported
@@ -147,3 +147,31 @@ instance Diagnostic DriverMessage where
-> WarningWithoutFlag
DriverBackpackModuleNotFound{}
-> ErrorWithoutFlag
+
+ diagnosticHints = \case
+ DriverUnknownMessage m
+ -> diagnosticHints m
+ DriverPsHeaderMessage _desc hints
+ -> hints
+ DriverMissingHomeModules{}
+ -> noHints
+ DriverUnusedPackages{}
+ -> noHints
+ DriverUnnecessarySourceImports{}
+ -> noHints
+ DriverDuplicatedModuleDeclaration{}
+ -> noHints
+ DriverModuleNotFound{}
+ -> noHints
+ DriverFileModuleNameMismatch{}
+ -> noHints
+ DriverUnexpectedSignature pi_mod_name buildingCabalPackage instantiations
+ -> if buildingCabalPackage == YesBuildingCabalPackage
+ then [SuggestAddSignatureCabalFile pi_mod_name]
+ else [SuggestSignatureInstantiations pi_mod_name (suggestInstantiatedWith pi_mod_name instantiations)]
+ DriverFileNotFound{}
+ -> noHints
+ DriverStaticPointersNotSupported
+ -> noHints
+ DriverBackpackModuleNotFound{}
+ -> noHints
diff --git a/compiler/GHC/Driver/Errors/Types.hs b/compiler/GHC/Driver/Errors/Types.hs
index 6f1684d789..2519d5597c 100644
--- a/compiler/GHC/Driver/Errors/Types.hs
+++ b/compiler/GHC/Driver/Errors/Types.hs
@@ -4,7 +4,6 @@ module GHC.Driver.Errors.Types (
GhcMessage(..)
, DriverMessage(..), DriverMessages
, BuildingCabalPackage(..)
- , InstantiationSuggestion(..)
, WarningMessages
, ErrorMessages
, WarnMsg
@@ -26,7 +25,7 @@ import GHC.Driver.Session
import GHC.Types.Error
import GHC.Unit.Module
-import GHC.Parser.Errors ( PsErrorDesc, PsHint )
+import GHC.Parser.Errors ( PsErrorDesc )
import GHC.Parser.Errors.Types ( PsMessage )
import GHC.Tc.Errors.Types ( TcRnMessage )
import GHC.HsToCore.Errors.Types ( DsMessage )
@@ -116,12 +115,11 @@ type DriverMessages = Messages DriverMessage
-- | A message from the driver.
data DriverMessage where
- -- | Simply wraps a generic 'DiagnosticMessage'.
+ -- | Simply wraps a generic 'Diagnostic' message @a@.
DriverUnknownMessage :: (Diagnostic a, Typeable a) => a -> DriverMessage
-
-- | A parse error in parsing a Haskell file header during dependency
-- analysis
- DriverPsHeaderMessage :: !PsErrorDesc -> ![PsHint] -> DriverMessage
+ DriverPsHeaderMessage :: !PsErrorDesc -> ![GhcHint] -> DriverMessage
{-| DriverMissingHomeModules is a warning (controlled with -Wmissing-home-modules) that
arises when running GHC in --make mode when some modules needed for compilation
@@ -189,7 +187,7 @@ data DriverMessage where
Test cases: driver/T12955
-}
- DriverUnexpectedSignature :: !ModuleName -> !BuildingCabalPackage -> [InstantiationSuggestion] -> DriverMessage
+ DriverUnexpectedSignature :: !ModuleName -> !BuildingCabalPackage -> GenInstantiations UnitId -> DriverMessage
{-| DriverFileNotFound occurs when the input file (e.g. given on the command line) can't be found.
@@ -211,19 +209,6 @@ data DriverMessage where
-}
DriverBackpackModuleNotFound :: !ModuleName -> DriverMessage
--- | An 'InstantiationSuggestion' for a '.hsig' file. This is generated
--- by GHC in case of a 'DriverUnexpectedSignature' and suggests a way
--- to instantiate a particular signature, where the first argument is
--- the signature name and the second is the module where the signature
--- was defined.
--- Example:
---
--- src/MyStr.hsig:2:11: error:
--- Unexpected signature: ‘MyStr’
--- (Try passing -instantiated-with="MyStr=<MyStr>"
--- replacing <MyStr> as necessary.)
-data InstantiationSuggestion = InstantiationSuggestion !ModuleName !Module
-
-- | Pass to a 'DriverMessage' the information whether or not the
-- '-fbuilding-cabal-package' flag is set.
data BuildingCabalPackage
diff --git a/compiler/GHC/Driver/Main.hs b/compiler/GHC/Driver/Main.hs
index 2d3e1e3925..8c09f4434c 100644
--- a/compiler/GHC/Driver/Main.hs
+++ b/compiler/GHC/Driver/Main.hs
@@ -570,7 +570,7 @@ tcRnModule' sum save_rn_syntax mod = do
logDiagnostics $ singleMessage $
mkPlainMsgEnvelope dflags (getLoc (hpm_module mod)) $
GhcDriverMessage $ DriverUnknownMessage $
- mkPlainDiagnostic reason warnMissingSafeHaskellMode
+ mkPlainDiagnostic reason noHints warnMissingSafeHaskellMode
tcg_res <- {-# SCC "Typecheck-Rename" #-}
ioMsgMaybe $ hoistTcRnMessage $
@@ -600,14 +600,14 @@ tcRnModule' sum save_rn_syntax mod = do
| otherwise -> (logDiagnostics $ singleMessage $
mkPlainMsgEnvelope dflags (warnSafeOnLoc dflags) $
GhcDriverMessage $ DriverUnknownMessage $
- mkPlainDiagnostic (WarningWithFlag Opt_WarnSafe) $
+ mkPlainDiagnostic (WarningWithFlag Opt_WarnSafe) noHints $
errSafe tcg_res')
False | safeHaskell dflags == Sf_Trustworthy &&
wopt Opt_WarnTrustworthySafe dflags ->
(logDiagnostics $ singleMessage $
mkPlainMsgEnvelope dflags (trustworthyOnLoc dflags) $
GhcDriverMessage $ DriverUnknownMessage $
- mkPlainDiagnostic (WarningWithFlag Opt_WarnTrustworthySafe) $
+ mkPlainDiagnostic (WarningWithFlag Opt_WarnTrustworthySafe) noHints $
errTwthySafe tcg_res')
False -> return ()
return tcg_res'
@@ -1201,7 +1201,7 @@ hscCheckSafeImports tcg_env = do
warnRules df (L loc (HsRule { rd_name = n })) =
mkPlainMsgEnvelope df (locA loc) $
DriverUnknownMessage $
- mkPlainDiagnostic WarningWithoutFlag $
+ mkPlainDiagnostic WarningWithoutFlag noHints $
text "Rule \"" <> ftext (snd $ unLoc n) <> text "\" ignored" $+$
text "User defined rules are disabled under Safe Haskell"
@@ -1279,7 +1279,7 @@ checkSafeImports tcg_env
| imv_is_safe v1 /= imv_is_safe v2
= throwOneError $
mkPlainErrorMsgEnvelope (imv_span v1) $
- GhcDriverMessage $ DriverUnknownMessage $ mkPlainError $
+ GhcDriverMessage $ DriverUnknownMessage $ mkPlainError noHints $
text "Module" <+> ppr (imv_name v1) <+>
(text $ "is imported both as a safe and unsafe import!")
| otherwise
@@ -1349,7 +1349,7 @@ hscCheckSafe' m l = do
-- can't load iface to check trust!
Nothing -> throwOneError $
mkPlainErrorMsgEnvelope l $
- GhcDriverMessage $ DriverUnknownMessage $ mkPlainError $
+ GhcDriverMessage $ DriverUnknownMessage $ mkPlainError noHints $
text "Can't load the interface file for" <+> ppr m
<> text ", to check that it can be safely imported"
@@ -1384,7 +1384,7 @@ hscCheckSafe' m l = do
inferredImportWarn dflags = singleMessage
$ mkMsgEnvelope dflags l (pkgQual state)
$ GhcDriverMessage $ DriverUnknownMessage
- $ mkPlainDiagnostic (WarningWithFlag Opt_WarnInferredSafeImports)
+ $ mkPlainDiagnostic (WarningWithFlag Opt_WarnInferredSafeImports) noHints
$ sep
[ text "Importing Safe-Inferred module "
<> ppr (moduleName m)
@@ -1393,7 +1393,7 @@ hscCheckSafe' m l = do
pkgTrustErr = singleMessage
$ mkErrorMsgEnvelope l (pkgQual state)
$ GhcDriverMessage $ DriverUnknownMessage
- $ mkPlainError
+ $ mkPlainError noHints
$ sep [ ppr (moduleName m)
<> text ": Can't be safely imported!"
, text "The package ("
@@ -1403,7 +1403,7 @@ hscCheckSafe' m l = do
modTrustErr = singleMessage
$ mkErrorMsgEnvelope l (pkgQual state)
$ GhcDriverMessage $ DriverUnknownMessage
- $ mkPlainError
+ $ mkPlainError noHints
$ sep [ ppr (moduleName m)
<> text ": Can't be safely imported!"
, text "The module itself isn't safe." ]
@@ -1453,7 +1453,7 @@ checkPkgTrust pkgs = do
$ mkErrorMsgEnvelope noSrcSpan (pkgQual state)
$ GhcDriverMessage
$ DriverUnknownMessage
- $ mkPlainError
+ $ mkPlainError noHints
$ pprWithUnitState state
$ text "The package ("
<> ppr pkg
@@ -1481,7 +1481,7 @@ markUnsafeInfer tcg_env whyUnsafe = do
(logDiagnostics $ singleMessage $
mkPlainMsgEnvelope dflags (warnUnsafeOnLoc dflags) $
GhcDriverMessage $ DriverUnknownMessage $
- mkPlainDiagnostic reason $
+ mkPlainDiagnostic reason noHints $
whyUnsafe' dflags)
liftIO $ writeIORef (tcg_safe_infer tcg_env) False
@@ -2079,7 +2079,7 @@ hscImport hsc_env str = runInteractiveHsc hsc_env $ do
[L _ i] -> return i
_ -> liftIO $ throwOneError $
mkPlainErrorMsgEnvelope noSrcSpan $
- GhcPsMessage $ PsUnknownMessage $ mkPlainError $
+ GhcPsMessage $ PsUnknownMessage $ mkPlainError noHints $
text "parse error in import declaration"
-- | Typecheck an expression (but don't run it)
@@ -2110,7 +2110,7 @@ hscParseExpr expr = do
Just (L _ (BodyStmt _ expr _ _)) -> return expr
_ -> throwOneError $
mkPlainErrorMsgEnvelope noSrcSpan $
- GhcPsMessage $ PsUnknownMessage $ mkPlainError $
+ GhcPsMessage $ PsUnknownMessage $ mkPlainError noHints $
text "not an expression:" <+> quotes (text expr)
hscParseStmt :: String -> Hsc (Maybe (GhciLStmt GhcPs))
diff --git a/compiler/GHC/Driver/Make.hs b/compiler/GHC/Driver/Make.hs
index f153e96e37..e73b3fb39d 100644
--- a/compiler/GHC/Driver/Make.hs
+++ b/compiler/GHC/Driver/Make.hs
@@ -58,7 +58,6 @@ import GHC.Driver.Backend
import GHC.Driver.Monad
import GHC.Driver.Env
import GHC.Driver.Errors
-import GHC.Driver.Errors.Ppr
import GHC.Driver.Errors.Types
import GHC.Driver.Main
@@ -2708,9 +2707,9 @@ summariseModule hsc_env old_summary_map is_boot (L loc wanted_mod)
$ DriverFileModuleNameMismatch pi_mod_name wanted_mod
when (hsc_src == HsigFile && isNothing (lookup pi_mod_name (homeUnitInstantiations home_unit))) $
- let suggestions = suggestInstantiatedWith pi_mod_name (homeUnitInstantiations home_unit)
+ let instantiations = homeUnitInstantiations home_unit
in throwE $ singleMessage $ mkPlainErrorMsgEnvelope pi_mod_name_loc
- $ DriverUnexpectedSignature pi_mod_name (checkBuildingCabalPackage dflags) suggestions
+ $ DriverUnexpectedSignature pi_mod_name (checkBuildingCabalPackage dflags) instantiations
liftIO $ makeNewModSummary hsc_env $ MakeNewModSummary
{ nms_src_fn = src_fn
@@ -2861,7 +2860,7 @@ withDeferredDiagnostics f = do
noModError :: HscEnv -> SrcSpan -> ModuleName -> FindResult -> MsgEnvelope GhcMessage
-- ToDo: we don't have a proper line number for this error
noModError hsc_env loc wanted_mod err
- = mkPlainErrorMsgEnvelope loc $ GhcDriverMessage $ DriverUnknownMessage $ mkPlainError $
+ = mkPlainErrorMsgEnvelope loc $ GhcDriverMessage $ DriverUnknownMessage $ mkPlainError noHints $
cannotFindModule hsc_env wanted_mod err
noHsFileErr :: SrcSpan -> String -> DriverMessages
diff --git a/compiler/GHC/Driver/MakeFile.hs b/compiler/GHC/Driver/MakeFile.hs
index 890054efd4..81336912de 100644
--- a/compiler/GHC/Driver/MakeFile.hs
+++ b/compiler/GHC/Driver/MakeFile.hs
@@ -307,7 +307,7 @@ findDependency hsc_env srcloc pkg imp is_boot include_pkg_deps = do
fail ->
throwOneError $
mkPlainErrorMsgEnvelope srcloc $
- GhcDriverMessage $ DriverUnknownMessage $ mkPlainError $
+ GhcDriverMessage $ DriverUnknownMessage $ mkPlainError noHints $
cannotFindModule hsc_env imp fail
-----------------------------
diff --git a/compiler/GHC/Driver/Pipeline.hs b/compiler/GHC/Driver/Pipeline.hs
index 9a5fa6819e..2ad69bc4a2 100644
--- a/compiler/GHC/Driver/Pipeline.hs
+++ b/compiler/GHC/Driver/Pipeline.hs
@@ -152,7 +152,7 @@ preprocess hsc_env input_fn mb_input_buf mb_phase =
handler (ProgramError msg) =
return $ Left $ singleMessage $
mkPlainErrorMsgEnvelope srcspan $
- DriverUnknownMessage $ mkPlainError $ text msg
+ DriverUnknownMessage $ mkPlainError noHints $ text msg
handler ex = throwGhcExceptionIO ex
to_driver_messages :: Messages GhcMessage -> Messages DriverMessage
diff --git a/compiler/GHC/HsToCore/Errors/Ppr.hs b/compiler/GHC/HsToCore/Errors/Ppr.hs
index f453a82743..b8d2a0a86c 100644
--- a/compiler/GHC/HsToCore/Errors/Ppr.hs
+++ b/compiler/GHC/HsToCore/Errors/Ppr.hs
@@ -1,4 +1,3 @@
-
{-# OPTIONS_GHC -fno-warn-orphans #-} -- instance Diagnostic DsMessage
module GHC.HsToCore.Errors.Ppr where
@@ -9,3 +8,4 @@ import GHC.HsToCore.Errors.Types
instance Diagnostic DsMessage where
diagnosticMessage (DsUnknownMessage m) = diagnosticMessage m
diagnosticReason (DsUnknownMessage m) = diagnosticReason m
+ diagnosticHints (DsUnknownMessage m) = diagnosticHints m
diff --git a/compiler/GHC/HsToCore/Monad.hs b/compiler/GHC/HsToCore/Monad.hs
index 9bc893f814..691f78b4ef 100644
--- a/compiler/GHC/HsToCore/Monad.hs
+++ b/compiler/GHC/HsToCore/Monad.hs
@@ -474,7 +474,7 @@ diagnosticDs reason warn
; dflags <- getDynFlags
; let msg = mkMsgEnvelope dflags loc (ds_unqual env) $
DsUnknownMessage $
- mkPlainDiagnostic reason warn
+ mkPlainDiagnostic reason noHints warn
; updMutVar (ds_msgs env) (\ msgs -> msg `addMessage` msgs) }
-- | Emit a warning only if the correct WarningWithoutFlag is set in the DynFlags
@@ -489,7 +489,7 @@ errDs err
; loc <- getSrcSpanDs
; let msg = mkErrorMsgEnvelope loc (ds_unqual env) $
DsUnknownMessage $
- mkPlainError err
+ mkPlainError noHints err
; updMutVar (ds_msgs env) (\ msgs -> msg `addMessage` msgs) }
-- | Issue an error, but return the expression for (), so that we can continue
diff --git a/compiler/GHC/Iface/Rename.hs b/compiler/GHC/Iface/Rename.hs
index 18ad1a55ce..04b227c50e 100644
--- a/compiler/GHC/Iface/Rename.hs
+++ b/compiler/GHC/Iface/Rename.hs
@@ -76,7 +76,7 @@ failWithRn doc = do
-- TODO: maybe associate this with a source location?
let msg = mkPlainErrorMsgEnvelope noSrcSpan $
TcRnUnknownMessage $
- mkPlainError doc
+ mkPlainError noHints doc
writeTcRef errs_var (msg `addMessage` errs)
failM
diff --git a/compiler/GHC/Parser.y b/compiler/GHC/Parser.y
index f9f7acc0fa..44ca8fa042 100644
--- a/compiler/GHC/Parser.y
+++ b/compiler/GHC/Parser.y
@@ -69,6 +69,7 @@ import GHC.Types.Name.Reader
import GHC.Types.Name.Occurrence ( varName, dataName, tcClsName, tvName, occNameFS, mkVarOcc, occNameString)
import GHC.Types.SrcLoc
import GHC.Types.Basic
+import GHC.Types.Error ( GhcHint(..) )
import GHC.Types.Fixity
import GHC.Types.ForeignCall
import GHC.Types.SourceFile
diff --git a/compiler/GHC/Parser/Errors.hs b/compiler/GHC/Parser/Errors.hs
index 570385c773..7a9c154ed8 100644
--- a/compiler/GHC/Parser/Errors.hs
+++ b/compiler/GHC/Parser/Errors.hs
@@ -9,12 +9,12 @@ module GHC.Parser.Errors
, LexErr(..)
, CmmParserError(..)
, LexErrKind(..)
- , PsHint(..)
, StarIsType (..)
)
where
import GHC.Prelude
+import GHC.Types.Error
import GHC.Types.SrcLoc
import GHC.Types.Name.Reader (RdrName)
import GHC.Types.Name.Occurrence (OccName)
@@ -27,7 +27,6 @@ import GHC.Hs.Type
import GHC.Hs.Lit
import GHC.Hs.Decls
import GHC.Core.Coercion.Axiom (Role)
-import GHC.Utils.Outputable (SDoc)
import GHC.Data.FastString
import GHC.Unit.Module.Name
@@ -82,7 +81,7 @@ data TransLayoutReason
data PsError = PsError
{ errDesc :: !PsErrorDesc -- ^ Error description
- , errHints :: ![PsHint] -- ^ Hints
+ , errHints :: ![GhcHint] -- ^ Hints
, errLoc :: !SrcSpan -- ^ Error position
}
@@ -396,17 +395,6 @@ data NumUnderscoreReason
| NumUnderscore_Float
deriving (Show,Eq,Ord)
-data PsHint
- = SuggestTH
- | SuggestRecursiveDo
- | SuggestDo
- | SuggestMissingDo
- | SuggestLetInDo
- | SuggestPatternSynonyms
- | SuggestInfixBindMaybeAtPat !RdrName
- | TypeApplicationsInPatternsOnlyDataCons -- ^ Type applications in patterns are only allowed on data constructors
-
-
data LexErrKind
= LexErrKind_EOF -- ^ End of input
| LexErrKind_UTF8 -- ^ UTF-8 decoding error
diff --git a/compiler/GHC/Parser/Errors/Ppr.hs b/compiler/GHC/Parser/Errors/Ppr.hs
index 8decaddfbe..4cc8da75f4 100644
--- a/compiler/GHC/Parser/Errors/Ppr.hs
+++ b/compiler/GHC/Parser/Errors/Ppr.hs
@@ -18,8 +18,9 @@ import GHC.Parser.Errors.Types
import GHC.Parser.Types
import GHC.Types.Basic
import GHC.Types.Error
+import GHC.Types.Hint (perhapsAsPat)
import GHC.Types.SrcLoc
-import GHC.Types.Name.Reader (starInfo, rdrNameOcc, opIsAt, mkUnqual)
+import GHC.Types.Name.Reader (starInfo, rdrNameOcc, mkUnqual)
import GHC.Types.Name.Occurrence (isSymOcc, occNameFS, varName)
import GHC.Utils.Outputable
import GHC.Utils.Misc
@@ -34,12 +35,23 @@ import GHC.Utils.Error (diagReasonSeverity)
instance Diagnostic PsMessage where
diagnosticMessage (PsUnknownMessage m) = diagnosticMessage m
diagnosticReason (PsUnknownMessage m) = diagnosticReason m
-
-mk_parser_err :: SrcSpan -> SDoc -> MsgEnvelope PsMessage
-mk_parser_err span doc = MsgEnvelope
+ -- FIXME(adinapoli) Fix it properly for #18516.
+ -- The reason why we temporarily set 'diagnosticHints' to be
+ -- the empty list is because currently the parser types does
+ -- not integrate tightly with the new diagnostic infrastructure
+ -- and as such hints and bundled together with the rendereded
+ -- diagnostic, and the same 'PsErrorDesc' is sometimes emitted
+ -- twice but with a different hint, which makes it hard to
+ -- untangle the two. Therefore, to smooth out the integration,
+ -- we provisionally tuck the hints directly into a 'PsUnknownMessage'
+ -- and we rendered them inside 'diagnosticMessage'.
+ diagnosticHints (PsUnknownMessage _m) = []
+
+mk_parser_err :: [GhcHint] -> SrcSpan -> SDoc -> MsgEnvelope PsMessage
+mk_parser_err hints span doc = MsgEnvelope
{ errMsgSpan = span
, errMsgContext = alwaysQualify
- , errMsgDiagnostic = PsUnknownMessage $ DiagnosticMessage (mkDecorated [doc]) ErrorWithoutFlag
+ , errMsgDiagnostic = PsUnknownMessage $ mkPlainError hints doc
, errMsgSeverity = SevError
}
@@ -47,7 +59,7 @@ mk_parser_warn :: DynFlags -> WarningFlag -> SrcSpan -> SDoc -> MsgEnvelope PsMe
mk_parser_warn df flag span doc = MsgEnvelope
{ errMsgSpan = span
, errMsgContext = alwaysQualify
- , errMsgDiagnostic = PsUnknownMessage $ DiagnosticMessage (mkDecorated [doc]) reason
+ , errMsgDiagnostic = PsUnknownMessage $ mkPlainDiagnostic reason noHints doc
, errMsgSeverity = diagReasonSeverity df reason
}
where
@@ -141,12 +153,12 @@ mkParserWarn df = \case
OperatorWhitespaceOccurrence_TightInfix -> mk_msg "tight infix"
mkParserErr :: PsError -> MsgEnvelope PsMessage
-mkParserErr err = mk_parser_err (errLoc err) $
+mkParserErr err = mk_parser_err (errHints err) (errLoc err) $
pprPsError (errDesc err) (errHints err)
--- | Render a 'PsErrorDesc' into an 'SDoc', with its 'PsHint's.
-pprPsError :: PsErrorDesc -> [PsHint] -> SDoc
-pprPsError desc hints = vcat (pp_err desc : map pp_hint hints)
+-- | Render a 'PsErrorDesc' into an 'SDoc', with its 'Hint's.
+pprPsError :: PsErrorDesc -> [GhcHint] -> SDoc
+pprPsError desc hints = vcat (pp_err desc : map ppr hints)
pp_err :: PsErrorDesc -> SDoc
pp_err = \case
@@ -384,7 +396,7 @@ pp_err = \case
-> text "Found a binding for the"
<+> quotes (text "@")
<+> text "operator in a pattern position."
- $$ perhaps_as_pat
+ $$ perhapsAsPat
PsErrLambdaCmdInFunAppCmd a
-> pp_unexpected_fun_app (text "lambda command") a
@@ -613,26 +625,3 @@ pp_unexpected_fun_app e a =
$$ nest 4 (ppr a)
$$ text "You could write it with parentheses"
$$ text "Or perhaps you meant to enable BlockArguments?"
-
-pp_hint :: PsHint -> SDoc
-pp_hint = \case
- SuggestTH -> text "Perhaps you intended to use TemplateHaskell"
- SuggestDo -> text "Perhaps this statement should be within a 'do' block?"
- SuggestMissingDo -> text "Possibly caused by a missing 'do'?"
- SuggestRecursiveDo -> text "Perhaps you intended to use RecursiveDo"
- SuggestLetInDo -> text "Perhaps you need a 'let' in a 'do' block?"
- $$ text "e.g. 'let x = 5' instead of 'x = 5'"
- SuggestPatternSynonyms -> text "Perhaps you intended to use PatternSynonyms"
-
- SuggestInfixBindMaybeAtPat fun
- -> text "In a function binding for the"
- <+> quotes (ppr fun)
- <+> text "operator."
- $$ if opIsAt fun
- then perhaps_as_pat
- else empty
- TypeApplicationsInPatternsOnlyDataCons ->
- text "Type applications in patterns are only allowed on data constructors."
-
-perhaps_as_pat :: SDoc
-perhaps_as_pat = text "Perhaps you meant an as-pattern, which must not be surrounded by whitespace"
diff --git a/compiler/GHC/Parser/Header.hs b/compiler/GHC/Parser/Header.hs
index bb0aee09be..7a60830d34 100644
--- a/compiler/GHC/Parser/Header.hs
+++ b/compiler/GHC/Parser/Header.hs
@@ -425,7 +425,7 @@ checkProcessArgsResult flags
liftIO $ throwErrors $ foldMap (singleMessage . mkMsg) flags
where mkMsg (L loc flag)
= mkPlainErrorMsgEnvelope loc $
- GhcDriverMessage $ DriverUnknownMessage $ mkPlainError $
+ GhcDriverMessage $ DriverUnknownMessage $ mkPlainError noHints $
text "unknown flag in {-# OPTIONS_GHC #-} pragma:" <+>
text flag
@@ -469,5 +469,5 @@ optionsParseError str loc =
throwErr :: SrcSpan -> SDoc -> a -- #15053
throwErr loc doc =
- let msg = mkPlainErrorMsgEnvelope loc $ GhcPsMessage $ PsUnknownMessage $ mkPlainError doc
+ let msg = mkPlainErrorMsgEnvelope loc $ GhcPsMessage $ PsUnknownMessage $ mkPlainError noHints doc
in throw $ mkSrcErr $ singleMessage msg
diff --git a/compiler/GHC/Parser/Lexer.x b/compiler/GHC/Parser/Lexer.x
index 2864e2998e..dc13d44493 100644
--- a/compiler/GHC/Parser/Lexer.x
+++ b/compiler/GHC/Parser/Lexer.x
@@ -109,6 +109,7 @@ import GHC.Data.Maybe
import GHC.Data.OrdList
import GHC.Utils.Misc ( readSignificandExponentPair, readHexSignificandExponentPair )
+import GHC.Types.Error ( GhcHint(..) )
import GHC.Types.SrcLoc
import GHC.Types.SourceText
import GHC.Types.Basic ( InlineSpec(..), RuleMatchInfo(..))
@@ -3044,11 +3045,11 @@ srcParseErr options buf len loc = PsError (PsErrParse token) suggests loc
ps_enabled = PatternSynonymsBit `xtest` pExtsBitmap options
sug c s = if c then Just s else Nothing
- sug_th = sug (not th_enabled && token == "$") SuggestTH -- #7396
- sug_rdo = sug (token == "<-" && mdoInLast100) SuggestRecursiveDo
- sug_do = sug (token == "<-" && not mdoInLast100) SuggestDo
+ sug_th = sug (not th_enabled && token == "$") (SuggestExtension LangExt.TemplateHaskell) -- #7396
+ sug_rdo = sug (token == "<-" && mdoInLast100) (SuggestExtension LangExt.RecursiveDo)
+ sug_do = sug (token == "<-" && not mdoInLast100) SuggestMissingDo
sug_let = sug (token == "=" && doInLast100) SuggestLetInDo -- #15849
- sug_pat = sug (not ps_enabled && pattern_ == "pattern ") SuggestPatternSynonyms -- #12429
+ sug_pat = sug (not ps_enabled && pattern_ == "pattern ") (SuggestExtension LangExt.PatternSynonyms) -- #12429
suggests
| null token = []
| otherwise = catMaybes [sug_th, sug_rdo, sug_do, sug_let, sug_pat]
diff --git a/compiler/GHC/Parser/PostProcess.hs b/compiler/GHC/Parser/PostProcess.hs
index 2eba1fa9e2..62d6c6b834 100644
--- a/compiler/GHC/Parser/PostProcess.hs
+++ b/compiler/GHC/Parser/PostProcess.hs
@@ -118,6 +118,7 @@ import GHC.Types.Name.Reader
import GHC.Types.Name
import GHC.Unit.Module (ModuleName)
import GHC.Types.Basic
+import GHC.Types.Error ( GhcHint(..) )
import GHC.Types.Fixity
import GHC.Types.SourceText
import GHC.Parser.Types
@@ -145,6 +146,7 @@ import GHC.Driver.Flags ( WarningFlag(..) )
import qualified Data.Semigroup as Semi
import GHC.Utils.Panic
import GHC.Utils.Panic.Plain
+import qualified GHC.LanguageExtensions as LangExt
import Control.Monad
import Text.ParserCombinators.ReadP as ReadP
@@ -1073,7 +1075,7 @@ checkImportDecl mPre mPost = do
checkPattern :: LocatedA (PatBuilder GhcPs) -> P (LPat GhcPs)
checkPattern = runPV . checkLPat
-checkPattern_hints :: [PsHint] -> PV (LocatedA (PatBuilder GhcPs)) -> P (LPat GhcPs)
+checkPattern_hints :: [GhcHint] -> PV (LocatedA (PatBuilder GhcPs)) -> P (LPat GhcPs)
checkPattern_hints hints pp = runPV_hints hints (pp >>= checkLPat)
checkLPat :: LocatedA (PatBuilder GhcPs) -> PV (LPat GhcPs)
@@ -1091,7 +1093,7 @@ checkPat loc (L l e@(PatBuilderVar (L ln c))) tyargs args
add_hint TypeApplicationsInPatternsOnlyDataCons $
patFail (locA l) (ppr e <+> hsep [text "@" <> ppr t | t <- tyargs])
| not (null args) && patIsRec c =
- add_hint SuggestRecursiveDo $
+ add_hint (SuggestExtension LangExt.RecursiveDo) $
patFail (locA l) (ppr e)
checkPat loc (L _ (PatBuilderAppType f _ t)) tyargs args =
checkPat loc f (t : tyargs) args
@@ -2715,7 +2717,7 @@ failOpFewArgs (L loc op) =
data PV_Context =
PV_Context
{ pv_options :: ParserOpts
- , pv_hints :: [PsHint] -- See Note [Parser-Validator Hint]
+ , pv_hints :: [GhcHint] -- See Note [Parser-Validator Hint]
}
data PV_Accum =
@@ -2765,7 +2767,7 @@ instance Monad PV where
runPV :: PV a -> P a
runPV = runPV_hints []
-runPV_hints :: [PsHint] -> PV a -> P a
+runPV_hints :: [GhcHint] -> PV a -> P a
runPV_hints hints m =
P $ \s ->
let
@@ -2786,7 +2788,7 @@ runPV_hints hints m =
PV_Ok acc' a -> POk (mkPState acc') a
PV_Failed acc' -> PFailed (mkPState acc')
-add_hint :: PsHint -> PV a -> PV a
+add_hint :: GhcHint -> PV a -> PV a
add_hint hint m =
let modifyHint ctx = ctx{pv_hints = pv_hints ctx ++ [hint]} in
PV (\ctx acc -> unPV m (modifyHint ctx) acc)
diff --git a/compiler/GHC/Tc/Errors/Ppr.hs b/compiler/GHC/Tc/Errors/Ppr.hs
index ffabf0f69c..650befdd8f 100644
--- a/compiler/GHC/Tc/Errors/Ppr.hs
+++ b/compiler/GHC/Tc/Errors/Ppr.hs
@@ -31,6 +31,7 @@ instance Diagnostic TcRnMessage where
-> mkDecorated [ text "The import item" <+> quotes (ppr ie) <+>
text "does not have an explicit import list"
]
+
diagnosticReason = \case
TcRnUnknownMessage m
-> diagnosticReason m
@@ -45,6 +46,20 @@ instance Diagnostic TcRnMessage where
TcRnMissingImportList{}
-> WarningWithFlag Opt_WarnMissingImportList
+ diagnosticHints = \case
+ TcRnUnknownMessage m
+ -> diagnosticHints m
+ TcRnImplicitLift{}
+ -> noHints
+ TcRnUnusedPatternBinds{}
+ -> noHints
+ TcRnDodgyImports{}
+ -> noHints
+ TcRnDodgyExports{}
+ -> noHints
+ TcRnMissingImportList{}
+ -> noHints
+
dodgy_msg :: (Outputable a, Outputable b) => SDoc -> a -> b -> SDoc
dodgy_msg kind tc ie
= sep [ text "The" <+> kind <+> text "item"
diff --git a/compiler/GHC/Tc/Module.hs b/compiler/GHC/Tc/Module.hs
index 50b832ed49..450e97819a 100644
--- a/compiler/GHC/Tc/Module.hs
+++ b/compiler/GHC/Tc/Module.hs
@@ -214,7 +214,7 @@ tcRnModule hsc_env mod_sum save_rn_syntax
logger = hsc_logger hsc_env
home_unit = hsc_home_unit hsc_env
err_msg = mkPlainErrorMsgEnvelope loc $
- TcRnUnknownMessage $ mkPlainError $
+ TcRnUnknownMessage $ mkPlainError noHints $
text "Module does not have a RealSrcSpan:" <+> ppr this_mod
pair :: (Module, SrcSpan)
@@ -3152,5 +3152,5 @@ mark_plugin_unsafe dflags = unless (gopt Opt_PluginTrustworthy dflags) $
singleMessage $
mkPlainMsgEnvelope dflags noSrcSpan $
TcRnUnknownMessage $
- mkPlainDiagnostic WarningWithoutFlag $
+ mkPlainDiagnostic WarningWithoutFlag noHints $
Outputable.text unsafeText
diff --git a/compiler/GHC/Tc/Utils/Monad.hs b/compiler/GHC/Tc/Utils/Monad.hs
index 730e666a2a..2d9298e12b 100644
--- a/compiler/GHC/Tc/Utils/Monad.hs
+++ b/compiler/GHC/Tc/Utils/Monad.hs
@@ -1038,7 +1038,7 @@ mkLongErrAt loc msg extra
let msg' = pprWithUnitState unit_state msg in
return $ mkErrorMsgEnvelope loc printer
$ TcRnUnknownMessage
- $ mkDecoratedError [msg', extra] }
+ $ mkDecoratedError noHints [msg', extra] }
mkTcRnMessage :: DiagnosticReason
-> SrcSpan
@@ -1058,7 +1058,7 @@ mkTcRnMessage reason loc important context extra
in
return $ mkMsgEnvelope dflags loc printer
$ TcRnUnknownMessage
- $ mkDecoratedDiagnostic reason errDocs }
+ $ mkDecoratedDiagnostic reason noHints errDocs }
addLongErrAt :: SrcSpan -> SDoc -> SDoc -> TcRn ()
addLongErrAt loc msg extra = mkLongErrAt loc msg extra >>= reportDiagnostic
@@ -1585,7 +1585,7 @@ add_diagnostic_at reason loc msg extra_info
dflags <- getDynFlags ;
let { dia = mkMsgEnvelope dflags loc printer $
TcRnUnknownMessage $
- mkDecoratedDiagnostic reason [msg, extra_info] } ;
+ mkDecoratedDiagnostic reason noHints [msg, extra_info] } ;
reportDiagnostic dia }
diff --git a/compiler/GHC/Types/Error.hs b/compiler/GHC/Types/Error.hs
index 0ec3e8756c..a97c690260 100644
--- a/compiler/GHC/Types/Error.hs
+++ b/compiler/GHC/Types/Error.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE GADTs #-}
{-# LANGUAGE DeriveTraversable #-}
{-# LANGUAGE DerivingStrategies #-}
{-# LANGUAGE FlexibleInstances #-}
@@ -24,12 +25,16 @@ module GHC.Types.Error
, Diagnostic (..)
, DiagnosticMessage (..)
, DiagnosticReason (..)
- , mkDiagnosticMessage
+ , DiagnosticHint (..)
, mkPlainDiagnostic
, mkPlainError
, mkDecoratedDiagnostic
, mkDecoratedError
+ -- * Hints and refactoring actions
+ , GhcHint (..)
+ , noHints
+
-- * Rendering Messages
, SDoc
@@ -67,6 +72,7 @@ import GHC.Utils.Json
import Data.Bifunctor
import Data.Foldable ( fold )
+import GHC.Types.Hint
{-
Note [Messages]
@@ -202,6 +208,13 @@ constraint.
class Diagnostic a where
diagnosticMessage :: a -> DecoratedSDoc
diagnosticReason :: a -> DiagnosticReason
+ diagnosticHints :: a -> [GhcHint]
+
+-- | A generic 'Hint' message, to be used with 'DiagnosticMessage'.
+data DiagnosticHint = DiagnosticHint !SDoc
+
+instance Outputable DiagnosticHint where
+ ppr (DiagnosticHint msg) = msg
-- | A generic 'Diagnostic' message, without any further classification or
-- provenance: By looking at a 'DiagnosticMessage' we don't know neither
@@ -211,30 +224,36 @@ class Diagnostic a where
data DiagnosticMessage = DiagnosticMessage
{ diagMessage :: !DecoratedSDoc
, diagReason :: !DiagnosticReason
+ , diagHints :: [GhcHint]
}
instance Diagnostic DiagnosticMessage where
diagnosticMessage = diagMessage
diagnosticReason = diagReason
+ diagnosticHints = diagHints
--- | Create a 'DiagnosticMessage' with a 'DiagnosticReason'
-mkDiagnosticMessage :: DecoratedSDoc -> DiagnosticReason -> DiagnosticMessage
-mkDiagnosticMessage = DiagnosticMessage
+-- | Helper function to use when no hints can be provided. Currently this function
+-- can be used to construct plain 'DiagnosticMessage' and add hints to them, but
+-- once #18516 will be fully executed, the main usage of this function would be in
+-- the implementation of the 'diagnosticHints' typeclass method, to report the fact
+-- that a particular 'Diagnostic' has no hints.
+noHints :: [GhcHint]
+noHints = mempty
-mkPlainDiagnostic :: DiagnosticReason -> SDoc -> DiagnosticMessage
-mkPlainDiagnostic rea doc = DiagnosticMessage (mkSimpleDecorated doc) rea
+mkPlainDiagnostic :: DiagnosticReason -> [GhcHint] -> SDoc -> DiagnosticMessage
+mkPlainDiagnostic rea hints doc = DiagnosticMessage (mkSimpleDecorated doc) rea hints
-- | Create an error 'DiagnosticMessage' holding just a single 'SDoc'
-mkPlainError :: SDoc -> DiagnosticMessage
-mkPlainError doc = DiagnosticMessage (mkSimpleDecorated doc) ErrorWithoutFlag
+mkPlainError :: [GhcHint] -> SDoc -> DiagnosticMessage
+mkPlainError hints doc = DiagnosticMessage (mkSimpleDecorated doc) ErrorWithoutFlag hints
-- | Create a 'DiagnosticMessage' from a list of bulleted SDocs and a 'DiagnosticReason'
-mkDecoratedDiagnostic :: DiagnosticReason -> [SDoc] -> DiagnosticMessage
-mkDecoratedDiagnostic rea docs = DiagnosticMessage (mkDecorated docs) rea
+mkDecoratedDiagnostic :: DiagnosticReason -> [GhcHint] -> [SDoc] -> DiagnosticMessage
+mkDecoratedDiagnostic rea hints docs = DiagnosticMessage (mkDecorated docs) rea hints
-- | Create an error 'DiagnosticMessage' from a list of bulleted SDocs
-mkDecoratedError :: [SDoc] -> DiagnosticMessage
-mkDecoratedError docs = DiagnosticMessage (mkDecorated docs) ErrorWithoutFlag
+mkDecoratedError :: [GhcHint] -> [SDoc] -> DiagnosticMessage
+mkDecoratedError hints docs = DiagnosticMessage (mkDecorated docs) ErrorWithoutFlag hints
-- | The reason /why/ a 'Diagnostic' was emitted in the first place.
-- Diagnostic messages are born within GHC with a very precise reason, which
diff --git a/compiler/GHC/Types/Hint.hs b/compiler/GHC/Types/Hint.hs
new file mode 100644
index 0000000000..23e00acfd8
--- /dev/null
+++ b/compiler/GHC/Types/Hint.hs
@@ -0,0 +1,130 @@
+{-# LANGUAGE ExistentialQuantification #-}
+{-# LANGUAGE LambdaCase #-}
+module GHC.Types.Hint where
+
+import GHC.Prelude
+
+import GHC.Utils.Outputable
+import GHC.Types.Name.Reader
+import GHC.LanguageExtensions
+import Data.Typeable
+import GHC.Unit.Module (ModuleName, Module)
+
+-- | A type for hints emitted by GHC.
+-- A /hint/ suggests a possible way to deal with a particular warning or error.
+data GhcHint
+ =
+ {-| An \"unknown\" hint. This type constructor allows arbitrary
+ -- hints to be embedded. The typical use case would be GHC plugins
+ -- willing to emit hints alongside their custom diagnostics.
+ -}
+ forall a. (Outputable a, Typeable a) => UnknownHint a
+ {-| Suggests adding a particular language extension. GHC will do its best trying
+ to guess when the user is using the syntax of a particular language extension
+ without having the relevant extension enabled.
+
+ Example: If the user uses the keyword \"mdo\" (and we are in a monadic block), but
+ the relevant extension is not enabled, GHC will emit a 'SuggestExtension RecursiveDo'.
+
+ Test case(s): parser/should_fail/T12429, parser/should_fail/T8501c,
+ parser/should_fail/T18251e, ... (and many more)
+
+ -}
+ | SuggestExtension !Extension
+ {-| Suggests that a monadic code block is probably missing a \"do\" keyword.
+
+ Example:
+ main =
+ putStrLn "hello"
+ putStrLn "world"
+
+ Test case(s): parser/should_fail/T8501a, parser/should_fail/readFail007,
+ parser/should_fail/InfixAppPatErr, parser/should_fail/T984
+ -}
+ | SuggestMissingDo
+ {-| Suggests that a \"let\" expression is needed in a \"do\" block.
+
+ Test cases: None (that explicitly test this particular hint is emitted).
+ -}
+ | SuggestLetInDo
+ -- FIXME(adn) This is not a hint but was migrated from the old \"PsHint\" type.
+ -- It will be removed in a further refactoring as part of #18516.
+ | SuggestInfixBindMaybeAtPat !RdrName
+ -- FIXME(adn) This is not a hint but was migrated from the old \"PsHint\" type.
+ -- It will be removed in a further refactoring as part of #18516.
+ | TypeApplicationsInPatternsOnlyDataCons
+ {-| Suggests to add an \".hsig\" signature file to the Cabal manifest.
+
+ Triggered by: 'GHC.Driver.Errors.Types.DriverUnexpectedSignature', if Cabal
+ is being used.
+
+ Example: See comment of 'DriverUnexpectedSignature'.
+
+ Test case(s): driver/T12955
+
+ -}
+ | SuggestAddSignatureCabalFile !ModuleName
+ {-| Suggests to explicitly list the instantiations for the signatures in
+ the GHC invocation command.
+
+ Triggered by: 'GHC.Driver.Errors.Types.DriverUnexpectedSignature', if Cabal
+ is /not/ being used.
+
+ Example: See comment of 'DriverUnexpectedSignature'.
+
+ Test case(s): driver/T12955
+ -}
+ | SuggestSignatureInstantiations !ModuleName [InstantiationSuggestion]
+
+
+instance Outputable GhcHint where
+ ppr = \case
+ UnknownHint m
+ -> ppr m
+ SuggestExtension ext
+ -> text "Perhaps you intended to use" <+> ppr ext
+ SuggestMissingDo
+ -> text "Possibly caused by a missing 'do'?"
+ SuggestLetInDo
+ -> text "Perhaps you need a 'let' in a 'do' block?"
+ $$ text "e.g. 'let x = 5' instead of 'x = 5'"
+ SuggestInfixBindMaybeAtPat fun
+ -> text "In a function binding for the"
+ <+> quotes (ppr fun)
+ <+> text "operator."
+ $$ if opIsAt fun
+ then perhapsAsPat
+ else empty
+ TypeApplicationsInPatternsOnlyDataCons
+ -> text "Type applications in patterns are only allowed on data constructors."
+ SuggestAddSignatureCabalFile pi_mod_name
+ -> text "Try adding" <+> quotes (ppr pi_mod_name)
+ <+> text "to the"
+ <+> quotes (text "signatures")
+ <+> text "field in your Cabal file."
+ SuggestSignatureInstantiations pi_mod_name suggestions
+ -> let suggested_instantiated_with =
+ hcat (punctuate comma $
+ [ ppr k <> text "=" <> ppr v
+ | InstantiationSuggestion k v <- suggestions
+ ])
+ in text "Try passing -instantiated-with=\"" <>
+ suggested_instantiated_with <> text "\"" $$
+ text "replacing <" <> ppr pi_mod_name <> text "> as necessary."
+
+perhapsAsPat :: SDoc
+perhapsAsPat = text "Perhaps you meant an as-pattern, which must not be surrounded by whitespace"
+
+
+-- | An 'InstantiationSuggestion' for a '.hsig' file. This is generated
+-- by GHC in case of a 'DriverUnexpectedSignature' and suggests a way
+-- to instantiate a particular signature, where the first argument is
+-- the signature name and the second is the module where the signature
+-- was defined.
+-- Example:
+--
+-- src/MyStr.hsig:2:11: error:
+-- Unexpected signature: ‘MyStr’
+-- (Try passing -instantiated-with="MyStr=<MyStr>"
+-- replacing <MyStr> as necessary.)
+data InstantiationSuggestion = InstantiationSuggestion !ModuleName !Module
diff --git a/compiler/GHC/Utils/Error.hs b/compiler/GHC/Utils/Error.hs
index a5eccbd7de..43692af28a 100644
--- a/compiler/GHC/Utils/Error.hs
+++ b/compiler/GHC/Utils/Error.hs
@@ -39,6 +39,7 @@ module GHC.Utils.Error (
mkPlainDiagnostic,
mkDecoratedError,
mkDecoratedDiagnostic,
+ noHints,
-- * Utilities
doIfSet, doIfSet_dyn,
diff --git a/compiler/ghc.cabal.in b/compiler/ghc.cabal.in
index 1b7c8d4eb4..0d6e92cf6e 100644
--- a/compiler/ghc.cabal.in
+++ b/compiler/ghc.cabal.in
@@ -640,6 +640,7 @@ Library
GHC.Types.Fixity.Env
GHC.Types.ForeignCall
GHC.Types.ForeignStubs
+ GHC.Types.Hint
GHC.Types.HpcInfo
GHC.Types.Id
GHC.Types.IPE
diff --git a/testsuite/tests/driver/T12955.stderr b/testsuite/tests/driver/T12955.stderr
index acf4000608..baa6fc6064 100644
--- a/testsuite/tests/driver/T12955.stderr
+++ b/testsuite/tests/driver/T12955.stderr
@@ -1,9 +1,11 @@
T12955.hsig:1:11: error:
Unexpected signature: ‘T12955’
- (Try passing -instantiated-with="T12955=<T12955>"
- replacing <T12955> as necessary.)
+ Suggested fix:
+ Try passing -instantiated-with="T12955=<T12955>"
+ replacing <T12955> as necessary.
T12955.hsig:1:11: error:
Unexpected signature: ‘T12955’
- (Try adding ‘T12955’ to the ‘signatures’ field in your Cabal file.)
+ Suggested fix:
+ Try adding ‘T12955’ to the ‘signatures’ field in your Cabal file.
diff --git a/testsuite/tests/parser/should_run/CountAstDeps.stdout b/testsuite/tests/parser/should_run/CountAstDeps.stdout
index 3980993668..242076d90c 100644
--- a/testsuite/tests/parser/should_run/CountAstDeps.stdout
+++ b/testsuite/tests/parser/should_run/CountAstDeps.stdout
@@ -1,4 +1,4 @@
-Found 256 Language.Haskell.Syntax module dependencies
+Found 257 Language.Haskell.Syntax module dependencies
GHC.Builtin.Names
GHC.Builtin.PrimOps
GHC.Builtin.Types
@@ -167,6 +167,7 @@ GHC.Types.Fixity
GHC.Types.Fixity.Env
GHC.Types.ForeignCall
GHC.Types.ForeignStubs
+GHC.Types.Hint
GHC.Types.HpcInfo
GHC.Types.IPE
GHC.Types.Id
diff --git a/testsuite/tests/parser/should_run/CountParserDeps.stdout b/testsuite/tests/parser/should_run/CountParserDeps.stdout
index 887161fd5e..c08cd67a52 100644
--- a/testsuite/tests/parser/should_run/CountParserDeps.stdout
+++ b/testsuite/tests/parser/should_run/CountParserDeps.stdout
@@ -1,4 +1,4 @@
-Found 262 GHC.Parser module dependencies
+Found 263 GHC.Parser module dependencies
GHC.Builtin.Names
GHC.Builtin.PrimOps
GHC.Builtin.Types
@@ -173,6 +173,7 @@ GHC.Types.Fixity
GHC.Types.Fixity.Env
GHC.Types.ForeignCall
GHC.Types.ForeignStubs
+GHC.Types.Hint
GHC.Types.HpcInfo
GHC.Types.IPE
GHC.Types.Id