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GHC 9.10.3 · lts/ghc-9.10.x · c74966e · 2026-09-27

Moduleghc-9.10.3GHC2021

GHC.Driver.DynFlags

  • 28 types
  • 2 classes
  • 77 values
  • Packageghc-9.10.3
  • Exports108
  • LanguageGHC2021
  • LicenceBSD-3-Clause
  • SourceFlags.hs

Dynamic flags and associated configuration types

69 declarations
datadata DumpFlag
#

Debugging flags

Constructors

Instances3Enum, Eq, Show
datadata GeneralFlag
#

Enumerates the simple on-or-off dynamic flags

Constructors

Instances3Enum, Eq, Show
datadata WarningFlag
#
Opt_WarnDuplicateExportsOpt_WarnDuplicateConstraintsOpt_WarnRedundantConstraintsOpt_WarnHiShadowsOpt_WarnImplicitPreludeOpt_WarnIncompletePatternsOpt_WarnIncompleteUniPatternsOpt_WarnIncompletePatternsRecUpdOpt_WarnOverflowedLiteralsOpt_WarnEmptyEnumerationsOpt_WarnMissingFieldsOpt_WarnMissingImportListOpt_WarnMissingMethodsOpt_WarnMissingSignaturesOpt_WarnMissingLocalSignaturesOpt_WarnNameShadowingOpt_WarnOverlappingPatternsOpt_WarnTypeDefaultsOpt_WarnMonomorphismOpt_WarnUnusedTopBindsOpt_WarnUnusedLocalBindsOpt_WarnUnusedPatternBindsOpt_WarnUnusedImportsOpt_WarnUnusedMatchesOpt_WarnUnusedTypePatternsOpt_WarnUnusedForallsOpt_WarnUnusedRecordWildcardsOpt_WarnRedundantBangPatternsOpt_WarnRedundantRecordWildcardsOpt_WarnDeprecatedFlagsOpt_WarnMissingMonadFailInstancesOpt_WarnSemigroupOpt_WarnDodgyExportsOpt_WarnDodgyImportsOpt_WarnOrphansOpt_WarnAutoOrphansOpt_WarnIdentitiesOpt_WarnTabsOpt_WarnUnrecognisedPragmasOpt_WarnMisplacedPragmasOpt_WarnDodgyForeignImportsOpt_WarnUnusedDoBindOpt_WarnWrongDoBindOpt_WarnAlternativeLayoutRuleTransitionalOpt_WarnUnsafeOpt_WarnSafeOpt_WarnTrustworthySafeOpt_WarnMissedSpecsOpt_WarnAllMissedSpecsOpt_WarnUnsupportedCallingConventionsOpt_WarnUnsupportedLlvmVersionOpt_WarnMissedExtraSharedLibOpt_WarnInlineRuleShadowingOpt_WarnTypedHolesOpt_WarnPartialTypeSignaturesOpt_WarnMissingExportedSignaturesOpt_WarnUntickedPromotedConstructorsOpt_WarnDerivingTypeableOpt_WarnDeferredTypeErrorsOpt_WarnDeferredOutOfScopeVariablesOpt_WarnNonCanonicalMonadInstancesOpt_WarnNonCanonicalMonadFailInstancesOpt_WarnNonCanonicalMonoidInstancesOpt_WarnMissingPatternSynonymSignaturesOpt_WarnUnrecognisedWarningFlagsOpt_WarnSimplifiableClassConstraintsOpt_WarnCPPUndefOpt_WarnUnbangedStrictPatternsOpt_WarnMissingHomeModulesOpt_WarnPartialFieldsOpt_WarnMissingExportListOpt_WarnInaccessibleCodeOpt_WarnStarIsTypeOpt_WarnStarBinderOpt_WarnImplicitKindVarsOpt_WarnSpaceAfterBangOpt_WarnMissingDerivingStrategiesOpt_WarnPrepositiveQualifiedModuleOpt_WarnUnusedPackagesOpt_WarnInferredSafeImportsOpt_WarnMissingSafeHaskellModeOpt_WarnCompatUnqualifiedImportsOpt_WarnDerivingDefaultsOpt_WarnInvalidHaddockOpt_WarnOperatorWhitespaceExtConflictOpt_WarnOperatorWhitespaceOpt_WarnAmbiguousFieldsOpt_WarnImplicitLiftOpt_WarnMissingKindSignaturesOpt_WarnMissingPolyKindSignaturesOpt_WarnMissingExportedPatternSynonymSignaturesOpt_WarnRedundantStrictnessFlagsOpt_WarnForallIdentifierOpt_WarnUnicodeBidirectionalFormatCharactersOpt_WarnGADTMonoLocalBindsOpt_WarnTypeEqualityOutOfScopeOpt_WarnTypeEqualityRequiresOperatorsOpt_WarnLoopySuperclassSolveOpt_WarnTermVariableCaptureOpt_WarnMissingRoleAnnotationsOpt_WarnImplicitRhsQuantificationOpt_WarnIncompleteExportWarningsOpt_WarnIncompleteRecordSelectorsOpt_WarnBadlyStagedTypesOpt_WarnInconsistentFlagsOpt_WarnDataKindsTCOpt_WarnDeprecatedTypeAbstractionsOpt_WarnDefaultedExceptionContext
Instances5Bounded, Enum, Eq, Ord, Show
datadata DiagnosticReason
#

The reason why a Diagnostic was emitted in the first place. Diagnostic messages are born within GHC with a very precise reason, which can be completely statically-computed (i.e. this is an error or a warning no matter what), or influenced by the specific state of the DynFlags at the moment of the creation of a new Diagnostic. For example, a parsing error is always going to be an error, whereas a 'WarningWithoutFlag Opt_WarnUnusedImports' might turn into an error due to '-Werror' or '-Werror=warn-unused-imports'. Interpreting a DiagnosticReason together with its associated Severity gives us the full picture.

Constructors

Instances3Eq, Show, Outputable
datadata Language
#
Haskell98Haskell2010GHC2021GHC2024
Instances7Bounded, Enum, Eq, Show, NFData, Outputable, …
valuegopt :: GeneralFlag -> DynFlags -> Bool
#

Test whether a GeneralFlag is set

Note that dynamicNow (i.e., dynamic objects built with `-dynamic-too`) always implicitly enables Opt_PIC, Opt_ExternalDynamicRefs, and disables Opt_SplitSections.

datadata DynFlags
#

Contains not only a collection of GeneralFlags but also a plethora of information relating to the compilation of a single file or GHC session

Constructors

classclass HasDynFlags (m :: Type -> Type) where
#

Methods

Instances13HasDynFlags, …
datadata GhcMode
#

The GhcMode tells us whether we're doing multi-module compilation (controlled via the GHC API) or one-shot (single-module) compilation. This makes a difference primarily to the GHC.Unit.Finder: in one-shot mode we look for interface files for imported modules, but in multi-module mode we look for source files in order to check whether they need to be recompiled.

Constructors

Instances2Eq, Outputable
datadata PackageArg
#

We accept flags which make packages visible, but how they select the package varies; this data type reflects what selection criterion is used.

Constructors

Instances3Eq, Show, Outputable
datadata ModRenaming
#

Represents the renaming that may be associated with an exposed package, e.g. the rns part of -package "foo (rns)".

Here are some example parsings of the package flags (where a string literal is punned to be a ModuleName:

  • -package foo is ModRenaming True []

  • -package foo () is ModRenaming False []

  • -package foo (A) is ModRenaming False [(A, A)]

  • -package foo (A as B) is ModRenaming False [(A, B)]

  • -package foo with (A as B) is ModRenaming True [(A, B)]

Constructors

Instances2Eq, Outputable
datadata Option
#

When invoking external tools as part of the compilation pipeline, we pass these a sequence of options on the command-line. Rather than just using a list of Strings, we use a type that allows us to distinguish between filepaths and 'other stuff'. The reason for this is that this type gives us a handle on transforming filenames, and filenames only, to whatever format they're expected to be on a particular platform.

Constructors

Instances1Eq
  • Eq OptionDefined in ghc-9.10.3 · GHC.Utils.CliOption
valueoptimisationFlags :: EnumSet GeneralFlag
#

The set of flags which affect optimisation for the purposes of recompilation avoidance. Specifically, these include flags which affect code generation but not the semantics of the program.

See Note [Ignoring some flag changes] in GHC.Iface.Recomp.Flags)

Manipulating DynFlags

valuelanguageExtensions :: Maybe Language -> [Extension]
#

The language extensions implied by the various language variants. When updating this be sure to update the flag documentation in docsusers_guideexts.

System tool settings and locations

valueversionedAppDir :: String -> ArchOS -> MaybeT IO FilePath
#

The directory for this version of ghc in the user's app directory The appdir used to be in ~/.ghc but to respect the XDG specification we want to move it under $XDG_DATA_HOME/ However, old tooling (like cabal) might still write package environments to the old directory, so we prefer that if a subdirectory of ~/.ghc with the correct target and GHC version suffix exists.

i.e. if ~.ghc$UNIQUE_SUBDIR exists we use that otherwise we use $XDG_DATA_HOME/$UNIQUE_SUBDIR

UNIQUE_SUBDIR is typically a combination of the target platform and GHC version

Linker/compiler information

2 declarations

Include specifications

5 declarations
valueaddQuoteInclude :: IncludeSpecs -> [String] -> IncludeSpecs
#

Append to the list of includes a path that shall be included using `-iquote` when the C compiler is called. These paths only apply when quoted includes are used. e.g. #include "foo.h"

SDoc

3 declarations

Platform features

10 declarations