{-# LANGUAGE ExistentialQuantification #-} module GHC.Types.Hint ( GhcHint(..) , InstantiationSuggestion(..) , LanguageExtensionHint(..) , suggestExtension , suggestExtensionWithInfo , suggestExtensions , suggestExtensionsWithInfo , suggestAnyExtension , suggestAnyExtensionWithInfo ) where import GHC.Prelude import GHC.Utils.Outputable import qualified GHC.LanguageExtensions as LangExt import Data.Typeable import GHC.Unit.Module (ModuleName, Module) import GHC.Hs.Extension (GhcTc) import GHC.Core.Coercion import GHC.Types.Basic (Activation, RuleName) import GHC.Parser.Errors.Basic import {-# SOURCE #-} Language.Haskell.Syntax.Expr -- This {-# SOURCE #-} import should be removable once -- 'Language.Haskell.Syntax.Bind' no longer depends on 'GHC.Tc.Types.Evidence'. data LanguageExtensionHint = -- | Suggest to enable the input extension. If the input 'SDoc' -- is not empty, it will contain some extra information about the -- why the extension is required, but it's totally irrelevant/redundant -- for IDEs and other tools. SuggestSingleExtension !SDoc !LangExt.Extension -- | Suggest to enable the input extensions. The list -- is to be intended as /disjuctive/ i.e. the user is -- suggested to enable /any/ of the extensions listed. If -- the input 'SDoc' is not empty, it will contain some extra -- information about the why the extensions are required, but -- it's totally irrelevant/redundant for IDEs and other tools. | SuggestAnyExtension !SDoc [LangExt.Extension] -- | Suggest to enable the input extensions. The list -- is to be intended as /conjunctive/ i.e. the user is -- suggested to enable /all/ the extensions listed. If -- the input 'SDoc' is not empty, it will contain some extra -- information about the why the extensions are required, but -- it's totally irrelevant/redundant for IDEs and other tools. | SuggestExtensions !SDoc [LangExt.Extension] -- | Suggests a single extension without extra user info. suggestExtension :: LangExt.Extension -> GhcHint suggestExtension ext = SuggestExtension (SuggestSingleExtension empty ext) -- | Like 'suggestExtension' but allows supplying extra info for the user. suggestExtensionWithInfo :: SDoc -> LangExt.Extension -> GhcHint suggestExtensionWithInfo extraInfo ext = SuggestExtension (SuggestSingleExtension extraInfo ext) -- | Suggests to enable /every/ extension in the list. suggestExtensions :: [LangExt.Extension] -> GhcHint suggestExtensions exts = SuggestExtension (SuggestExtensions empty exts) -- | Like 'suggestExtensions' but allows supplying extra info for the user. suggestExtensionsWithInfo :: SDoc -> [LangExt.Extension] -> GhcHint suggestExtensionsWithInfo extraInfo exts = SuggestExtension (SuggestExtensions extraInfo exts) -- | Suggests to enable /any/ extension in the list. suggestAnyExtension :: [LangExt.Extension] -> GhcHint suggestAnyExtension exts = SuggestExtension (SuggestAnyExtension empty exts) -- | Like 'suggestAnyExtension' but allows supplying extra info for the user. suggestAnyExtensionWithInfo :: SDoc -> [LangExt.Extension] -> GhcHint suggestAnyExtensionWithInfo extraInfo exts = SuggestExtension (SuggestAnyExtension extraInfo exts) -- | 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 !LanguageExtensionHint {-| 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 {-| 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] {-| Suggests to use spaces instead of tabs. Triggered by: 'GHC.Parser.Errors.Types.PsWarnTab'. Examples: None Test Case(s): None -} | SuggestUseSpaces {-| Suggests adding a whitespace after the given symbol. Examples: None Test Case(s): parser/should_compile/T18834a.hs -} | SuggestUseWhitespaceAfter !OperatorWhitespaceSymbol {-| Suggests adding a whitespace around the given operator symbol, as it might be repurposed as special syntax by a future language extension. The second parameter is how such operator occurred, if in a prefix, suffix or tight infix position. Triggered by: 'GHC.Parser.Errors.Types.PsWarnOperatorWhitespace'. Example: h a b = a+b -- not OK, no spaces around '+'. Test Case(s): parser/should_compile/T18834b.hs -} | SuggestUseWhitespaceAround !String !OperatorWhitespaceOccurrence {-| Suggests wrapping an expression in parentheses Examples: None Test Case(s): None -} | SuggestParentheses {-| Suggests to increase the -fmax-pmcheck-models limit for the pattern match checker. Triggered by: 'GHC.HsToCore.Errors.Types.DsMaxPmCheckModelsReached' Test case(s): pmcheck/should_compile/TooManyDeltas pmcheck/should_compile/TooManyDeltas pmcheck/should_compile/T11822 -} | SuggestIncreaseMaxPmCheckModels {-| Suggests adding a type signature, typically to resolve ambiguity or help GHC inferring types. -} | SuggestAddTypeSignature {-| Suggests to explicitly discard the result of a monadic action by binding the result to the '_' wilcard. Example: main = do _ <- getCurrentTime -} | SuggestBindToWildcard !(LHsExpr GhcTc) | SuggestAddInlineOrNoInlinePragma !Var !Activation | SuggestAddPhaseToCompetingRule !RuleName {-| Suggests increasing the limit for the number of iterations in the simplifier. -} | SuggestIncreaseSimplifierIterations {-| Suggests to explicitly import 'Type' from the 'Data.Kind' module, because using "*" to mean 'Data.Kind.Type' relies on the StarIsType extension, which will become deprecated in the future. Triggered by: 'GHC.Parser.Errors.Types.PsWarnStarIsType' Example: None Test case(s): wcompat-warnings/WCompatWarningsOn.hs -} | SuggestUseTypeFromDataKind {-| Suggests placing the 'qualified' keyword /after/ the module name. Triggered by: 'GHC.Parser.Errors.Types.PsWarnImportPreQualified' Example: None Test case(s): module/mod184.hs -} | SuggestQualifiedAfterModuleName {-| Suggests using TemplateHaskell quotation syntax. Triggered by: 'GHC.Parser.Errors.Types.PsErrEmptyDoubleQuotes' only if TemplateHaskell is enabled. Example: None Test case(s): parser/should_fail/T13450TH.hs -} | SuggestThQuotationSyntax {-| Suggests alternative roles in case we found an illegal one. Triggered by: 'GHC.Parser.Errors.Types.PsErrIllegalRoleName' Example: None Test case(s): roles/should_fail/Roles7.hs -} | SuggestRoles [Role] {-| Suggests qualifying the '*' operator in modules where StarIsType is enabled. Triggered by: 'GHC.Parser.Errors.Types.PsWarnStarBinder' Test case(s): warnings/should_compile/StarBinder.hs -} | SuggestQualifyStarOperator {-| Suggests that a type signature should have form :: in order to be accepted by GHC. Triggered by: 'GHC.Parser.Errors.Types.PsErrInvalidTypeSignature' Test case(s): parser/should_fail/T3811 -} | SuggestTypeSignatureForm -- | 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=" -- replacing as necessary.) data InstantiationSuggestion = InstantiationSuggestion !ModuleName !Module