Moduleghc-9.10.3GHC2021

GHC.Utils.Error

9 types
1 class
51 values

Packageghc-9.10.3
Exports61
LanguageGHC2021
LicenceBSD-3-Clause
SourceError.hs

Basic types

6 declarations

datadata Validity' a

Constructors

IsValid
Everything is fine
NotValid a
A problem, and some indication of why

Instances1Functor

Functor Validity'Defined in ghc-9.10.3 · GHC.Utils.Error

typetype Validity = Validity' SDoc

Monomorphic version of Validity' specialised for SDocs.

valueandValid :: Validity' a -> Validity' a -> Validity' a

valueallValid :: [Validity' a] -> Validity' a

If they aren't all valid, return the first

valuegetInvalids :: [Validity' a] -> [a]

datadata Severity

Used to describe warnings and errors o The message has a file/line/column heading, plus "warning:" or "error:", added by mkLocMessage o With SevIgnore the message is suppressed o Output is intended for end users

Constructors

SevIgnore
Ignore this message, for example in case of suppression of warnings users don't want to see. See Note [Suppressing Messages]
SevWarning
SevError

Instances5Eq, Ord, Show, Outputable, ToJson

Eq SeverityDefined in ghc-9.10.3 · GHC.Types.Error
Ord SeverityDefined in ghc-9.10.3 · GHC.Types.Error
Show SeverityDefined in ghc-9.10.3 · GHC.Types.Error
Outputable SeverityDefined in ghc-9.10.3 · GHC.Types.Error
ToJson SeverityDefined in ghc-9.10.3 · GHC.Types.Error

Messages

11 declarations

classclass HasDefaultDiagnosticOpts (DiagnosticOpts a) => Diagnostic a where

A class identifying a diagnostic. Dictionary.com defines a diagnostic as:

"a message output by a computer diagnosing an error in a computer program, computer system, or component device".

A Diagnostic carries the actual description of the message (which, in GHC's case, it can be an error or a warning) and the reason why such message was generated in the first place.

Associated types

type family DiagnosticOpts a
Type of configuration options for the diagnostic.

Methods

diagnosticMessage :: DiagnosticOpts a -> a -> DecoratedSDoc
Extract the error message text from a Diagnostic.
diagnosticReason :: a -> DiagnosticReason
Extract the reason for this diagnostic. For warnings, a DiagnosticReason includes the warning flag.
diagnosticHints :: a -> [GhcHint]
Extract any hints a user might use to repair their code to avoid this diagnostic.
diagnosticCode :: a -> Maybe DiagnosticCode
Get the DiagnosticCode associated with this Diagnostic. This can return Nothing for at least two reasons:
1. The message might be from a plugin that does not supply codes.
2. The message might not yet have been assigned a code. See the Diagnostic instance for DiagnosticMessage.
Ideally, case (2) would not happen, but because some errors in GHC still use the old system of just writing the error message in-place (instead of using a dedicated error type and constructor), we do not have error codes for all errors. #18516 tracks our progress toward this goal.

Instances8Diagnostic, …

Diagnostic DriverMessageDefined in ghc-9.10.3 · GHC.Driver.Errors.Ppr · orphan
Diagnostic GhcMessageDefined in ghc-9.10.3 · GHC.Driver.Errors.Ppr · orphan
Diagnostic DsMessageDefined in ghc-9.10.3 · GHC.HsToCore.Errors.Ppr · orphan
Diagnostic IfaceMessageDefined in ghc-9.10.3 · GHC.Iface.Errors.Ppr · orphan
Diagnostic PsMessageDefined in ghc-9.10.3 · GHC.Parser.Errors.Ppr · orphan
Diagnostic TcRnMessageDefined in ghc-9.10.3 · GHC.Tc.Errors.Ppr · orphan
Diagnostic DiagnosticMessageDefined in ghc-9.10.3 · GHC.Types.Error
HasDefaultDiagnosticOpts opts => Diagnostic (UnknownDiagnostic opts)Defined in ghc-9.10.3 · GHC.Types.Error

datadata MsgEnvelope e

An envelope for GHC's facts about a running program, parameterised over the domain-specific (i.e. parsing, typecheck-renaming, etc) diagnostics.

To say things differently, GHC emits diagnostics about the running program, each of which is wrapped into a MsgEnvelope that carries specific information like where the error happened, etc. Finally, multiple MsgEnvelopes are aggregated into Messages that are returned to the user.

Constructors

MsgEnvelope
- errMsgSpan :: SrcSpan
  The SrcSpan is used for sorting errors into line-number order
- errMsgContext :: NamePprCtx
- errMsgDiagnostic :: e
- errMsgSeverity :: Severity
- errMsgReason :: ResolvedDiagnosticReason
  The actual reason caused this message
  See Note [Warnings controlled by multiple flags]

Instances5Functor, Foldable, Traversable, Show, ToJson

Functor MsgEnvelopeDefined in ghc-9.10.3 · GHC.Types.Error
Foldable MsgEnvelopeDefined in ghc-9.10.3 · GHC.Types.Error
Traversable MsgEnvelopeDefined in ghc-9.10.3 · GHC.Types.Error
Show (MsgEnvelope DiagnosticMessage)Defined in ghc-9.10.3 · GHC.Types.Error
Diagnostic e => ToJson (MsgEnvelope e)Defined in ghc-9.10.3 · GHC.Types.Error

datadata MessageClass

The class for a diagnostic message. The main purpose is to classify a message within GHC, to distinguish it from a debug/dump message vs a proper diagnostic, for which we include a DiagnosticReason.

Constructors

MCOutput
MCFatal
MCInteractive
MCDump
Log message intended for compiler developers No file/line/column stuff
MCInfo
Log messages intended for end users. No file/line/column stuff.
MCDiagnostic Severity ResolvedDiagnosticReason (Maybe DiagnosticCode)
Diagnostics from the compiler. This constructor is very powerful as it allows the construction of a MessageClass with a completely arbitrary permutation of Severity and DiagnosticReason. As such, users are encouraged to use the mkMCDiagnostic smart constructor instead. Use this constructor directly only if you need to construct and manipulate diagnostic messages directly, for example inside GHC.Utils.Error. In all the other circumstances, especially when emitting compiler diagnostics, use the smart constructor.
The Maybe DiagnosticCode field carries a code (if available) for this diagnostic. If you are creating a message not tied to any error-message type, then use Nothing. In the long run, this really should always have a DiagnosticCode. See Note [Diagnostic codes].

Instances1ToJson

ToJson MessageClassDefined in ghc-9.10.3 · GHC.Types.Error

newtypenewtype SDoc

Represents a pretty-printable document.

To display an SDoc, use printSDoc, printSDocLn, bufLeftRenderSDoc, or renderWithContext. Avoid calling runSDoc directly as it breaks the abstraction layer.

Instances8IsString, Outputable, IsLine, IsDoc, IsOutput, JsRender, …

IsString SDocDefined in ghc-9.10.3 · GHC.Utils.Outputable
Outputable SDocDefined in ghc-9.10.3 · GHC.Utils.Outputable
IsLine SDocDefined in ghc-9.10.3 · GHC.Utils.Outputable
IsDoc SDocDefined in ghc-9.10.3 · GHC.Utils.Outputable
IsOutput SDocDefined in ghc-9.10.3 · GHC.Utils.Outputable
JsRender SDocDefined in ghc-9.10.3 · GHC.JS.Ppr
OutputableP env SDocDefined in ghc-9.10.3 · GHC.Utils.Outputable
type Line SDoc = SDocDefined in ghc-9.10.3 · GHC.Utils.Outputable

newtypenewtype DecoratedSDoc

A DecoratedSDoc is isomorphic to a '[SDoc]' but it carries the invariant that the input '[SDoc]' needs to be rendered decorated into its final form, where the typical case would be adding bullets between each elements of the list. The type of decoration depends on the formatting function used, but in practice GHC uses the formatBulleted.

valueunDecorated :: DecoratedSDoc -> [SDoc]

newtypenewtype Messages e

A collection of messages emitted by GHC during error reporting. A diagnostic message is typically a warning or an error. See Note [Messages].

INVARIANT: All the messages in this collection must be relevant, i.e. their Severity should not be SevIgnore. The smart constructor mkMessages will filter out any message which Severity is SevIgnore.

Instances7Functor, Foldable, Traversable, Semigroup, Monoid, Outputable, …

Functor MessagesDefined in ghc-9.10.3 · GHC.Types.Error
Foldable MessagesDefined in ghc-9.10.3 · GHC.Types.Error
Traversable MessagesDefined in ghc-9.10.3 · GHC.Types.Error
Semigroup (Messages e)Defined in ghc-9.10.3 · GHC.Types.Error
Monoid (Messages e)Defined in ghc-9.10.3 · GHC.Types.Error
Diagnostic e => Outputable (Messages e)Defined in ghc-9.10.3 · GHC.Types.Error
Diagnostic e => ToJson (Messages e)Defined in ghc-9.10.3 · GHC.Types.Error

valuemkMessages :: Bag (MsgEnvelope e) -> Messages e

valueunionMessages :: Messages e -> Messages e -> Messages e

Joins two collections of messages together. See Note [Discarding Messages].

valueerrorsFound :: Diagnostic e => Messages e -> Bool

Are there any hard errors here? -Werror warnings are not detected. If you want to check for -Werror warnings, use errorsOrFatalWarningsFound.

valueisEmptyMessages :: Messages e -> Bool

Formatting

valuepprMessageBag :: Bag SDoc -> SDoc

valuepprMsgEnvelopeBagWithLoc

:: Diagnostic e
=> DiagnosticOpts e
-> Bag (MsgEnvelope e)
-> [SDoc]

valuepprMsgEnvelopeBagWithLocDefault

:: Diagnostic e
=> Bag (MsgEnvelope e)
-> [SDoc]

Print the messages with the suitable default configuration, usually not what you want but sometimes you don't really care about what the configuration is (for example, if the message is in a panic).

valuepprMessages :: Diagnostic e => DiagnosticOpts e -> Messages e -> SDoc

valuepprLocMsgEnvelope

:: Diagnostic e
=> DiagnosticOpts e
-> MsgEnvelope e
-> SDoc

valuepprLocMsgEnvelopeDefault :: Diagnostic e => MsgEnvelope e -> SDoc

valueformatBulleted :: DecoratedSDoc -> SDoc

Formats the input list of structured document, where each element of the list gets a bullet.

Construction

datadata DiagOpts

Constructors

DiagOpts
- diag_warning_flags :: !EnumSet WarningFlag
  Enabled warnings
- diag_fatal_warning_flags :: !EnumSet WarningFlag
  Fatal warnings
- diag_custom_warning_categories :: !WarningCategorySet
  Enabled custom warning categories
- diag_fatal_custom_warning_categories :: !WarningCategorySet
  Fatal custom warning categories
- diag_warn_is_error :: !Bool
  Treat warnings as errors
- diag_reverse_errors :: !Bool
  Reverse error reporting order
- diag_max_errors :: !Maybe Int
  Max reported error count
- diag_ppr_ctx :: !SDocContext
  Error printing context

valueemptyDiagOpts :: DiagOpts

valuediag_wopt :: WarningFlag -> DiagOpts -> Bool

valuediag_fatal_wopt :: WarningFlag -> DiagOpts -> Bool

valueemptyMessages :: Messages e

valuemkDecorated :: [SDoc] -> DecoratedSDoc

Creates a new DecoratedSDoc out of a list of SDoc.

valuemkLocMessage

:: MessageClass
What kind of message?
-> SrcSpan
location
-> SDoc
message
-> SDoc

valuemkMsgEnvelope

:: Diagnostic e
=> DiagOpts
-> SrcSpan
-> NamePprCtx
-> e
-> MsgEnvelope e

Wrap a Diagnostic in a MsgEnvelope, recording its location. If you know your Diagnostic is an error, consider using mkErrorMsgEnvelope, which does not require looking at the DiagOpts

valuemkPlainMsgEnvelope

:: Diagnostic e
=> DiagOpts
-> SrcSpan
-> e
-> MsgEnvelope e

Variant that doesn't care about qualified/unqualified names.

valuemkPlainErrorMsgEnvelope :: Diagnostic e => SrcSpan -> e -> MsgEnvelope e

Variant of mkPlainMsgEnvelope which can be used when we are sure we are constructing a diagnostic with a ErrorWithoutFlag reason.

valuemkErrorMsgEnvelope

:: Diagnostic e
=> SrcSpan
-> NamePprCtx
-> e
-> MsgEnvelope e

Wrap a Diagnostic in a MsgEnvelope, recording its location. Precondition: the diagnostic is, in fact, an error. That is, diagnosticReason msg == ErrorWithoutFlag.

valuemkMCDiagnostic

Make a MessageClass for a given DiagnosticReason, consulting the DiagOpts.

valueerrorDiagnostic :: MessageClass

Varation of mkMCDiagnostic which can be used when we are sure the input DiagnosticReason is ErrorWithoutFlag and there is no diagnostic code.

valuediagReasonSeverity :: DiagOpts -> DiagnosticReason -> Severity

Computes the right Severity for the input DiagnosticReason out of the 'DiagOpts. This function has to be called when a diagnostic is constructed, i.e. with a 'DiagOpts "snapshot" taken as close as possible to where a particular diagnostic message is built, otherwise the computed Severity might not be correct, due to the mutable nature of the DynFlags in GHC.

valuemkPlainError :: [GhcHint] -> SDoc -> DiagnosticMessage

Create an error DiagnosticMessage holding just a single SDoc

valuemkPlainDiagnostic

valuemkDecoratedError :: [GhcHint] -> [SDoc] -> DiagnosticMessage

Create an error DiagnosticMessage from a list of bulleted SDocs

valuemkDecoratedDiagnostic

Create a DiagnosticMessage from a list of bulleted SDocs and a DiagnosticReason

valuenoHints :: [GhcHint]

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.

Utilities

1 declaration

valuegetCaretDiagnostic :: MessageClass -> SrcSpan -> IO SDoc

Issuing messages during compilation

17 declarations

valueputMsg :: Logger -> SDoc -> IO ()

valueprintInfoForUser :: Logger -> NamePprCtx -> SDoc -> IO ()

valueprintOutputForUser :: Logger -> NamePprCtx -> SDoc -> IO ()

valuelogInfo :: Logger -> SDoc -> IO ()

valuelogOutput :: Logger -> SDoc -> IO ()

Like logInfo but with SevOutput rather then SevInfo

valueerrorMsg :: Logger -> SDoc -> IO ()

valuefatalErrorMsg :: Logger -> SDoc -> IO ()

valuecompilationProgressMsg :: Logger -> SDoc -> IO ()

valueshowPass :: Logger -> String -> IO ()

valuewithTiming

:: MonadIO m
=> Logger
-> SDoc
The name of the phase
-> (a -> ())
A function to force the result (often either const () or rnf)
-> m a
The body of the phase to be timed
-> m a

Time a compilation phase.

When timings are enabled (e.g. with the -v2 flag), the allocations and CPU time used by the phase will be reported to stderr. Consider a typical usage: withTiming getDynFlags (text "simplify") force PrintTimings pass. When timings are enabled the following costs are included in the produced accounting,

The cost of executing pass to a result r in WHNF
The cost of evaluating force r to WHNF (e.g. ())

The choice of the force function depends upon the amount of forcing desired; the goal here is to ensure that the cost of evaluating the result is, to the greatest extent possible, included in the accounting provided by withTiming. Often the pass already sufficiently forces its result during construction; in this case const () is a reasonable choice. In other cases, it is necessary to evaluate the result to normal form, in which case something like Control.DeepSeq.rnf is appropriate.

To avoid adversely affecting compiler performance when timings are not requested, the result is only forced when timings are enabled.

See Note [withTiming] for more.

valuewithTimingSilent

:: MonadIO m
=> Logger
-> SDoc
The name of the phase
-> (a -> ())
A function to force the result (often either const () or rnf)
-> m a
The body of the phase to be timed
-> m a

Same as withTiming, but doesn't print timings in the console (when given -vN, N >= 2 or -ddump-timings).

See Note [withTiming] for more.

valuedebugTraceMsg :: Logger -> Int -> SDoc -> IO ()

valueghcExit :: Logger -> Int -> IO ()

valueprettyPrintGhcErrors :: ExceptionMonad m => Logger -> m a -> m a

valuetraceCmd :: Logger -> String -> String -> IO a -> IO a

Trace a command (when verbosity level >= 3)

valuetraceSystoolCommand :: Logger -> String -> IO a -> IO a

Record in the eventlog when the given tool command starts and finishes, prepending the given String with "systool:", to easily be able to collect and process all the systool events.

For those events to show up in the eventlog, you need to run GHC with -v2 or -ddump-timings.

valuesortMsgBag :: Maybe DiagOpts -> Bag (MsgEnvelope e) -> [MsgEnvelope e]