CLabel

Documentation

data CLabel

CLabel is an abstract type that supports the following operations:

• Pretty printing
• In a C file, does it need to be declared before use? (i.e. is it guaranteed to be already in scope in the places we need to refer to it?)
• If it needs to be declared, what type (code or data) should it be declared to have?
• Is it visible outside this object file or not?
• Is it "dynamic" (see details below)
• Eq and Ord, so that we can make sets of CLabels (currently only used in outputting C as far as I can tell, to avoid generating more than one declaration for any given label).
• Converting an info table label into an entry label.

CLabel usage is a bit messy in GHC as they are used in a number of different contexts:

• By the C-- AST to identify labels
• By the unregisterised C code generator (PprC) for naming functions (hence the name CLabel)
• By the native and LLVM code generators to identify labels

For extra fun, each of these uses a slightly different subset of constructors (e.g. AsmTempLabel and AsmTempDerivedLabel are used only in the NCG and LLVM backends).

In general, we use IdLabel to represent Haskell things early in the pipeline. However, later optimization passes will often represent blocks they create with LocalBlockLabel where there is no obvious Name to hang off the label.

Instances

Eq CLabel

Defined in CLabel

Methods

(==) :: CLabel -> CLabel -> Bool

(/=) :: CLabel -> CLabel -> Bool

Ord CLabel

Defined in CLabel

Methods

compare :: CLabel -> CLabel -> Ordering

(<) :: CLabel -> CLabel -> Bool

(<=) :: CLabel -> CLabel -> Bool

(>) :: CLabel -> CLabel -> Bool

(>=) :: CLabel -> CLabel -> Bool

max :: CLabel -> CLabel -> CLabel

min :: CLabel -> CLabel -> CLabel

Outputable CLabel

Defined in CLabel

Methods

ppr :: CLabel -> SDoc

pprPrec :: Rational -> CLabel -> SDoc

data ForeignLabelSource

Record where a foreign label is stored.

Constructors

ForeignLabelInPackage UnitId

Label is in a named package

ForeignLabelInExternalPackage

Label is in some external, system package that doesn't also contain compiled Haskell code, and is not associated with any .hi files. We don't have to worry about Haskell code being inlined from external packages. It is safe to treat the RTS package as "external".

ForeignLabelInThisPackage

Label is in the package currenly being compiled. This is only used for creating hacky tmp labels during code generation. Don't use it in any code that might be inlined across a package boundary (ie, core code) else the information will be wrong relative to the destination module.

Instances

Eq ForeignLabelSource

Defined in CLabel

Methods

(==) :: ForeignLabelSource -> ForeignLabelSource -> Bool

(/=) :: ForeignLabelSource -> ForeignLabelSource -> Bool

Ord ForeignLabelSource

Defined in CLabel

Methods

compare :: ForeignLabelSource -> ForeignLabelSource -> Ordering

(<) :: ForeignLabelSource -> ForeignLabelSource -> Bool

(<=) :: ForeignLabelSource -> ForeignLabelSource -> Bool

(>) :: ForeignLabelSource -> ForeignLabelSource -> Bool

(>=) :: ForeignLabelSource -> ForeignLabelSource -> Bool

max :: ForeignLabelSource -> ForeignLabelSource -> ForeignLabelSource

min :: ForeignLabelSource -> ForeignLabelSource -> ForeignLabelSource

Outputable ForeignLabelSource

Defined in CLabel

Methods

ppr :: ForeignLabelSource -> SDoc

pprPrec :: Rational -> ForeignLabelSource -> SDoc

pprDebugCLabel :: CLabel -> SDoc

For debugging problems with the CLabel representation. We can't make a Show instance for CLabel because lots of its components don't have instances. The regular Outputable instance only shows the label name, and not its other info.

mkClosureLabel :: Name -> CafInfo -> CLabel

mkSRTLabel :: Unique -> CLabel

mkInfoTableLabel :: Name -> CafInfo -> CLabel

mkEntryLabel :: Name -> CafInfo -> CLabel

mkRednCountsLabel :: Name -> CLabel

mkConInfoTableLabel :: Name -> CafInfo -> CLabel

mkApEntryLabel :: Bool -> Int -> CLabel

mkApInfoTableLabel :: Bool -> Int -> CLabel

mkClosureTableLabel :: Name -> CafInfo -> CLabel

mkBytesLabel :: Name -> CLabel

mkLocalBlockLabel :: Unique -> CLabel

mkLocalClosureLabel :: Name -> CafInfo -> CLabel

mkLocalInfoTableLabel :: Name -> CafInfo -> CLabel

mkLocalClosureTableLabel :: Name -> CafInfo -> CLabel

mkBlockInfoTableLabel :: Name -> CafInfo -> CLabel

mkBitmapLabel :: Unique -> CLabel

mkStringLitLabel :: Unique -> CLabel

mkAsmTempLabel :: Uniquable a => a -> CLabel

mkAsmTempDerivedLabel :: CLabel -> FastString -> CLabel

mkAsmTempEndLabel :: CLabel -> CLabel

mkAsmTempDieLabel :: CLabel -> CLabel

Construct a label for a DWARF Debug Information Entity (DIE) describing another symbol.

mkDirty_MUT_VAR_Label :: CLabel

mkNonmovingWriteBarrierEnabledLabel :: CLabel

mkUpdInfoLabel :: CLabel

mkBHUpdInfoLabel :: CLabel

mkIndStaticInfoLabel :: CLabel

mkMainCapabilityLabel :: CLabel

mkMAP_FROZEN_CLEAN_infoLabel :: CLabel

mkMAP_FROZEN_DIRTY_infoLabel :: CLabel

mkMAP_DIRTY_infoLabel :: CLabel

mkSMAP_FROZEN_CLEAN_infoLabel :: CLabel

mkSMAP_FROZEN_DIRTY_infoLabel :: CLabel

mkSMAP_DIRTY_infoLabel :: CLabel

mkBadAlignmentLabel :: CLabel

mkArrWords_infoLabel :: CLabel

mkSRTInfoLabel :: Int -> CLabel

mkTopTickyCtrLabel :: CLabel

mkCAFBlackHoleInfoTableLabel :: CLabel

mkRtsPrimOpLabel :: PrimOp -> CLabel

mkRtsSlowFastTickyCtrLabel :: String -> CLabel

mkSelectorInfoLabel :: Bool -> Int -> CLabel

mkSelectorEntryLabel :: Bool -> Int -> CLabel

mkCmmInfoLabel :: UnitId -> FastString -> CLabel

mkCmmEntryLabel :: UnitId -> FastString -> CLabel

mkCmmRetInfoLabel :: UnitId -> FastString -> CLabel

mkCmmRetLabel :: UnitId -> FastString -> CLabel

mkCmmCodeLabel :: UnitId -> FastString -> CLabel

mkCmmDataLabel :: UnitId -> FastString -> CLabel

mkCmmClosureLabel :: UnitId -> FastString -> CLabel

mkRtsApFastLabel :: FastString -> CLabel

mkPrimCallLabel :: PrimCall -> CLabel

mkForeignLabel :: FastString -> Maybe Int -> ForeignLabelSource -> FunctionOrData -> CLabel

Make a foreign label

addLabelSize :: CLabel -> Int -> CLabel

Update the label size field in a ForeignLabel

foreignLabelStdcallInfo :: CLabel -> Maybe Int

Get the label size field from a ForeignLabel

isBytesLabel :: CLabel -> Bool

Whether label is a top-level string literal

isForeignLabel :: CLabel -> Bool

Whether label is a non-haskell label (defined in C code)

isSomeRODataLabel :: CLabel -> Bool

Whether label is a .rodata label

isStaticClosureLabel :: CLabel -> Bool

Whether label is a static closure label (can come from haskell or cmm)

mkCCLabel :: CostCentre -> CLabel

mkCCSLabel :: CostCentreStack -> CLabel

data DynamicLinkerLabelInfo

Constructors

CodeStub

SymbolPtr

GotSymbolPtr

GotSymbolOffset

Instances

Eq DynamicLinkerLabelInfo

Defined in CLabel

Methods

(==) :: DynamicLinkerLabelInfo -> DynamicLinkerLabelInfo -> Bool

(/=) :: DynamicLinkerLabelInfo -> DynamicLinkerLabelInfo -> Bool

Ord DynamicLinkerLabelInfo

Defined in CLabel

Methods

compare :: DynamicLinkerLabelInfo -> DynamicLinkerLabelInfo -> Ordering

(<) :: DynamicLinkerLabelInfo -> DynamicLinkerLabelInfo -> Bool

(<=) :: DynamicLinkerLabelInfo -> DynamicLinkerLabelInfo -> Bool

(>) :: DynamicLinkerLabelInfo -> DynamicLinkerLabelInfo -> Bool

(>=) :: DynamicLinkerLabelInfo -> DynamicLinkerLabelInfo -> Bool

max :: DynamicLinkerLabelInfo -> DynamicLinkerLabelInfo -> DynamicLinkerLabelInfo

min :: DynamicLinkerLabelInfo -> DynamicLinkerLabelInfo -> DynamicLinkerLabelInfo

mkDynamicLinkerLabel :: DynamicLinkerLabelInfo -> CLabel -> CLabel

dynamicLinkerLabelInfo :: CLabel -> Maybe (DynamicLinkerLabelInfo, CLabel)

mkPicBaseLabel :: CLabel

mkDeadStripPreventer :: CLabel -> CLabel

mkHpcTicksLabel :: Module -> CLabel

Predicates

hasCAF :: CLabel -> Bool

needsCDecl :: CLabel -> Bool

maybeLocalBlockLabel :: CLabel -> Maybe BlockId

If a label is a local block label then return just its BlockId, otherwise Nothing.

externallyVisibleCLabel :: CLabel -> Bool

Is a CLabel visible outside this object file or not? From the point of view of the code generator, a name is externally visible if it has to be declared as exported in the .o file's symbol table; that is, made non-static.

isMathFun :: CLabel -> Bool

Check whether a label corresponds to a C function that has a prototype in a system header somehere, or is built-in to the C compiler. For these labels we avoid generating our own C prototypes.

isCFunctionLabel :: CLabel -> Bool

isGcPtrLabel :: CLabel -> Bool

labelDynamic :: DynFlags -> Module -> CLabel -> Bool

Does a CLabel need dynamic linkage?

When referring to data in code, we need to know whether that data resides in a DLL or not. [Win32 only.] labelDynamic returns True if the label is located in a DLL, be it a data reference or not.

isLocalCLabel :: Module -> CLabel -> Bool

Is a CLabel defined in the current module being compiled?

Sometimes we can optimise references within a compilation unit in ways that we couldn't for inter-module references. This provides a conservative estimate of whether a CLabel lives in the current module.

mayRedirectTo :: CLabel -> CLabel -> Bool

Conversions

toClosureLbl :: CLabel -> CLabel

toSlowEntryLbl :: CLabel -> CLabel

toEntryLbl :: CLabel -> CLabel

toInfoLbl :: CLabel -> CLabel

hasHaskellName :: CLabel -> Maybe Name

pprCLabel :: DynFlags -> CLabel -> SDoc

isInfoTableLabel :: CLabel -> Bool

Whether label is points to some kind of info table

isConInfoTableLabel :: CLabel -> Bool

Whether label is points to constructor info table