Copyright	(C) 2026 QBayLogic B.V.
License	BSD2 (see the file LICENSE)
Maintainer	QBayLogic B.V. <devops@qbaylogic.com>
Safe Haskell	Safe-Inferred
Language	Haskell2010

Clash.Warning

Contents

Warning options
Flag-parsing state transitions

Description

Named warnings and the options controlling them.

Every warning Clash can emit has a name and can be controlled individually with GHC-style flags:

-W<name>: enable the warning
-Wno-<name>: disable the warning
-Werror=<name>: enable the warning and promote it to an error
-Wwarn=<name>, -Wno-error=<name>: demote the warning back to a warning, also exempting it from a global -Werror

Note that Clash parses its flags in a separate pass from GHC's, so ordering between GHC's global -Werror and -Wwarn=<name> is not positional: an explicit -Wwarn=<name> always wins over a global -Werror. Ordering among the Clash warning flags themselves is positional (last one wins).

Synopsis

data ClashWarning
warningName :: ClashWarning -> String
parseWarningName :: String -> Maybe ClashWarning
data WarningOpts = WarningOpts {
- warn_enabled :: Set ClashWarning
- warn_fatal :: Set ClashWarning
- warn_nonFatal :: Set ClashWarning
}
defWarningOpts :: WarningOpts
wopt :: ClashWarning -> WarningOpts -> Bool
woptFatal :: Bool -> ClashWarning -> WarningOpts -> Bool
enableWarning :: ClashWarning -> WarningOpts -> WarningOpts
disableWarning :: ClashWarning -> WarningOpts -> WarningOpts
promoteWarning :: ClashWarning -> WarningOpts -> WarningOpts
demoteWarning :: ClashWarning -> WarningOpts -> WarningOpts

Documentation

data ClashWarning Source #

Warnings Clash can emit. See the module documentation of Clash.Warning for the command line flags controlling each of these.

Constructors

WarnDubiousPrimitive	A primitive marked with `WarnAlways` was instantiated, e.g. a primitive that only approximates its Haskell model. Flag: `-Wclash-dubious-primitive`
WarnNonSynthesizable	A primitive marked with `WarnNonSynthesizable` was instantiated outside of a test bench context. Flag: `-Wclash-non-synthesizable`
WarnPrimitiveDefinition	A primitive's Haskell definition looks problematic: it isn't marked OPAQUE, its result is always an error, or its blackbox uses arguments the Haskell definition doesn't use. Flag: `-Wclash-primitive-definition`
WarnCastSpecialization	A function is specialized on a non work-free cast, possibly duplicating work. Flag: `-Wclash-cast-specialization`
WarnIntegerNarrowing	A `toInteger` conversion narrows its argument to the width of `Int`, possibly dropping most significant bits. Flag: `-Wclash-integer-narrowing`
WarnUnmatchableConstant	A case subject evaluated to a constant that matches none of the alternatives, usually a missing reduction rule in the primitive evaluator. Only reported when invariants are being checked (`-fclash-debug`). Flag: `-Wclash-unmatchable-constant`

Instances

Instances details

Bounded ClashWarning Source #
Instance details Defined in Clash.Warning Methods minBound :: ClashWarning # maxBound :: ClashWarning #
Enum ClashWarning Source #
Instance details Defined in Clash.Warning Methods succ :: ClashWarning -> ClashWarning # pred :: ClashWarning -> ClashWarning # toEnum :: Int -> ClashWarning # fromEnum :: ClashWarning -> Int # enumFrom :: ClashWarning -> [ClashWarning] # enumFromThen :: ClashWarning -> ClashWarning -> [ClashWarning] # enumFromTo :: ClashWarning -> ClashWarning -> [ClashWarning] # enumFromThenTo :: ClashWarning -> ClashWarning -> ClashWarning -> [ClashWarning] #
Generic ClashWarning Source #
Instance details Defined in Clash.Warning Associated Types type Rep ClashWarning :: Type -> Type # Methods from :: ClashWarning -> Rep ClashWarning x # to :: Rep ClashWarning x -> ClashWarning #
Show ClashWarning Source #
Instance details Defined in Clash.Warning Methods showsPrec :: Int -> ClashWarning -> ShowS # show :: ClashWarning -> String # showList :: [ClashWarning] -> ShowS #
NFData ClashWarning Source #
Instance details Defined in Clash.Warning Methods rnf :: ClashWarning -> () #
Eq ClashWarning Source #
Instance details Defined in Clash.Warning Methods (==) :: ClashWarning -> ClashWarning -> Bool # (/=) :: ClashWarning -> ClashWarning -> Bool #
Ord ClashWarning Source #
Instance details Defined in Clash.Warning Methods compare :: ClashWarning -> ClashWarning -> Ordering # (<) :: ClashWarning -> ClashWarning -> Bool # (<=) :: ClashWarning -> ClashWarning -> Bool # (>) :: ClashWarning -> ClashWarning -> Bool # (>=) :: ClashWarning -> ClashWarning -> Bool # max :: ClashWarning -> ClashWarning -> ClashWarning # min :: ClashWarning -> ClashWarning -> ClashWarning #
Hashable ClashWarning Source #
Instance details Defined in Clash.Warning Methods hashWithSalt :: Int -> ClashWarning -> Int # hash :: ClashWarning -> Int #
type Rep ClashWarning Source #
Instance details Defined in Clash.Warning type Rep ClashWarning = D1 ('MetaData "ClashWarning" "Clash.Warning" "clash-lib-1.11.0-inplace" 'False) ((C1 ('MetaCons "WarnDubiousPrimitive" 'PrefixI 'False) (U1 :: Type -> Type) :+: (C1 ('MetaCons "WarnNonSynthesizable" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "WarnPrimitiveDefinition" 'PrefixI 'False) (U1 :: Type -> Type))) :+: (C1 ('MetaCons "WarnCastSpecialization" 'PrefixI 'False) (U1 :: Type -> Type) :+: (C1 ('MetaCons "WarnIntegerNarrowing" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "WarnUnmatchableConstant" 'PrefixI 'False) (U1 :: Type -> Type))))

warningName :: ClashWarning -> String Source #

The name of a warning as used in command line flags, e.g. clash-dubious-primitive for WarnDubiousPrimitive.

parseWarningName :: String -> Maybe ClashWarning Source #

Inverse of warningName

Warning options

data WarningOpts Source #

Which warnings are enabled, and which of them are fatal. Construct with defWarningOpts and the state transitions below; query with wopt and woptFatal.

Constructors

WarningOpts
Fields warn_enabled :: Set ClashWarning Warnings that are enabled. All warnings are enabled by default. warn_fatal :: Set ClashWarning Warnings explicitly promoted to errors with `-Werror=<name>` warn_nonFatal :: Set ClashWarning Warnings explicitly demoted with `-Wwarn=<name>`; these are also exempt from a global `-Werror`

Instances

Instances details

Generic WarningOpts Source #
Instance details Defined in Clash.Warning Associated Types type Rep WarningOpts :: Type -> Type # Methods from :: WarningOpts -> Rep WarningOpts x # to :: Rep WarningOpts x -> WarningOpts #
Show WarningOpts Source #
Instance details Defined in Clash.Warning Methods showsPrec :: Int -> WarningOpts -> ShowS # show :: WarningOpts -> String # showList :: [WarningOpts] -> ShowS #
NFData WarningOpts Source #
Instance details Defined in Clash.Warning Methods rnf :: WarningOpts -> () #
Eq WarningOpts Source #
Instance details Defined in Clash.Warning Methods (==) :: WarningOpts -> WarningOpts -> Bool # (/=) :: WarningOpts -> WarningOpts -> Bool #
Hashable WarningOpts Source #
Instance details Defined in Clash.Warning Methods hashWithSalt :: Int -> WarningOpts -> Int # hash :: WarningOpts -> Int #
type Rep WarningOpts Source #
Instance details Defined in Clash.Warning type Rep WarningOpts = D1 ('MetaData "WarningOpts" "Clash.Warning" "clash-lib-1.11.0-inplace" 'False) (C1 ('MetaCons "WarningOpts" 'PrefixI 'True) (S1 ('MetaSel ('Just "warn_enabled") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (Set ClashWarning)) :: (S1 ('MetaSel ('Just "warn_fatal") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (Set ClashWarning)) :: S1 ('MetaSel ('Just "warn_nonFatal") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (Set ClashWarning)))))

defWarningOpts :: WarningOpts Source #

All warnings enabled, none fatal

wopt :: ClashWarning -> WarningOpts -> Bool Source #

Is the given warning enabled?

woptFatal :: Bool -> ClashWarning -> WarningOpts -> Bool Source #

Should the given warning be promoted to an error? The first argument indicates whether all warnings should be treated as errors (-Werror).

Flag-parsing state transitions

enableWarning :: ClashWarning -> WarningOpts -> WarningOpts Source #

-W<name>

disableWarning :: ClashWarning -> WarningOpts -> WarningOpts Source #

-Wno-<name>

promoteWarning :: ClashWarning -> WarningOpts -> WarningOpts Source #

-Werror=<name>. Implies -W<name>, like in GHC.

demoteWarning :: ClashWarning -> WarningOpts -> WarningOpts Source #

-Wwarn=<name> / -Wno-error=<name>