----------------------------------------------------------------------------- -- -- Object-file symbols (called CLabel for histerical raisins). -- -- (c) The University of Glasgow 2004-2006 -- ----------------------------------------------------------------------------- {-# LANGUAGE CPP #-} module CLabel ( CLabel, -- abstract type NeedExternDecl (..), ForeignLabelSource(..), pprDebugCLabel, mkClosureLabel, mkSRTLabel, mkInfoTableLabel, mkEntryLabel, mkRednCountsLabel, mkConInfoTableLabel, mkApEntryLabel, mkApInfoTableLabel, mkClosureTableLabel, mkBytesLabel, mkLocalBlockLabel, mkLocalClosureLabel, mkLocalInfoTableLabel, mkLocalClosureTableLabel, mkBlockInfoTableLabel, mkBitmapLabel, mkStringLitLabel, mkAsmTempLabel, mkAsmTempDerivedLabel, mkAsmTempEndLabel, mkAsmTempDieLabel, mkDirty_MUT_VAR_Label, mkNonmovingWriteBarrierEnabledLabel, mkUpdInfoLabel, mkBHUpdInfoLabel, mkIndStaticInfoLabel, mkMainCapabilityLabel, mkMAP_FROZEN_CLEAN_infoLabel, mkMAP_FROZEN_DIRTY_infoLabel, mkMAP_DIRTY_infoLabel, mkSMAP_FROZEN_CLEAN_infoLabel, mkSMAP_FROZEN_DIRTY_infoLabel, mkSMAP_DIRTY_infoLabel, mkBadAlignmentLabel, mkArrWords_infoLabel, mkSRTInfoLabel, mkTopTickyCtrLabel, mkCAFBlackHoleInfoTableLabel, mkRtsPrimOpLabel, mkRtsSlowFastTickyCtrLabel, mkSelectorInfoLabel, mkSelectorEntryLabel, mkCmmInfoLabel, mkCmmEntryLabel, mkCmmRetInfoLabel, mkCmmRetLabel, mkCmmCodeLabel, mkCmmDataLabel, mkRtsCmmDataLabel, mkCmmClosureLabel, mkRtsApFastLabel, mkPrimCallLabel, mkForeignLabel, addLabelSize, foreignLabelStdcallInfo, isBytesLabel, isForeignLabel, isSomeRODataLabel, isStaticClosureLabel, mkCCLabel, mkCCSLabel, DynamicLinkerLabelInfo(..), mkDynamicLinkerLabel, dynamicLinkerLabelInfo, mkPicBaseLabel, mkDeadStripPreventer, mkHpcTicksLabel, -- * Predicates hasCAF, needsCDecl, maybeLocalBlockLabel, externallyVisibleCLabel, isMathFun, isCFunctionLabel, isGcPtrLabel, labelDynamic, isLocalCLabel, mayRedirectTo, -- * Conversions toClosureLbl, toSlowEntryLbl, toEntryLbl, toInfoLbl, hasHaskellName, pprCLabel, isInfoTableLabel, isConInfoTableLabel ) where #include "HsVersions.h" import GhcPrelude import IdInfo import BasicTypes import {-# SOURCE #-} BlockId (BlockId, mkBlockId) import Packages import Module import Name import Unique import PrimOp import CostCentre import Outputable import FastString import DynFlags import GHC.Platform import UniqSet import Util import PprCore ( {- instances -} ) -- ----------------------------------------------------------------------------- -- The CLabel type {- | '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. -} data CLabel = -- | A label related to the definition of a particular Id or Con in a .hs file. IdLabel Name CafInfo IdLabelInfo -- ^ encodes the suffix of the label -- | A label from a .cmm file that is not associated with a .hs level Id. | CmmLabel UnitId -- ^ what package the label belongs to. NeedExternDecl -- ^ does the label need an "extern .." declaration FastString -- ^ identifier giving the prefix of the label CmmLabelInfo -- ^ encodes the suffix of the label -- | A label with a baked-in \/ algorithmically generated name that definitely -- comes from the RTS. The code for it must compile into libHSrts.a \/ libHSrts.so -- If it doesn't have an algorithmically generated name then use a CmmLabel -- instead and give it an appropriate UnitId argument. | RtsLabel RtsLabelInfo -- | A label associated with a block. These aren't visible outside of the -- compilation unit in which they are defined. These are generally used to -- name blocks produced by Cmm-to-Cmm passes and the native code generator, -- where we don't have a 'Name' to associate the label to and therefore can't -- use 'IdLabel'. | LocalBlockLabel {-# UNPACK #-} !Unique -- | A 'C' (or otherwise foreign) label. -- | ForeignLabel FastString -- ^ name of the imported label. (Maybe Int) -- ^ possible '@n' suffix for stdcall functions -- When generating C, the '@n' suffix is omitted, but when -- generating assembler we must add it to the label. ForeignLabelSource -- ^ what package the foreign label is in. FunctionOrData -- | Local temporary label used for native (or LLVM) code generation; must not -- appear outside of these contexts. Use primarily for debug information | AsmTempLabel {-# UNPACK #-} !Unique -- | A label \"derived\" from another 'CLabel' by the addition of a suffix. -- Must not occur outside of the NCG or LLVM code generators. | AsmTempDerivedLabel CLabel FastString -- ^ suffix | StringLitLabel {-# UNPACK #-} !Unique | CC_Label CostCentre | CCS_Label CostCentreStack -- | These labels are generated and used inside the NCG only. -- They are special variants of a label used for dynamic linking -- see module PositionIndependentCode for details. | DynamicLinkerLabel DynamicLinkerLabelInfo CLabel -- | This label is generated and used inside the NCG only. -- It is used as a base for PIC calculations on some platforms. -- It takes the form of a local numeric assembler label '1'; and -- is pretty-printed as 1b, referring to the previous definition -- of 1: in the assembler source file. | PicBaseLabel -- | A label before an info table to prevent excessive dead-stripping on darwin | DeadStripPreventer CLabel -- | Per-module table of tick locations | HpcTicksLabel Module -- | Static reference table | SRTLabel {-# UNPACK #-} !Unique -- | A bitmap (function or case return) | LargeBitmapLabel {-# UNPACK #-} !Unique deriving Eq -- | Indicate if "GHC.CmmToC" has to generate an extern declaration for the -- label (e.g. "extern StgWordArray(foo)"). The type is fixed to StgWordArray. -- -- Symbols from the RTS don't need "extern" declarations because they are -- exposed via "includes/Stg.h" with the appropriate type. See 'needsCDecl'. -- -- The fixed StgWordArray type led to "conflicting types" issues with user -- provided Cmm files (not in the RTS) that declare data of another type (#15467 -- and test for #17920). Hence the Cmm parser considers that labels in data -- sections don't need the "extern" declaration (just add one explicitly if you -- need it). -- -- See https://gitlab.haskell.org/ghc/ghc/-/wikis/commentary/compiler/backends/ppr-c#prototypes -- for why extern declaration are needed at all. newtype NeedExternDecl = NeedExternDecl Bool deriving (Ord,Eq) -- This is laborious, but necessary. We can't derive Ord because -- Unique doesn't have an Ord instance. Note nonDetCmpUnique in the -- implementation. See Note [No Ord for Unique] -- This is non-deterministic but we do not currently support deterministic -- code-generation. See Note [Unique Determinism and code generation] instance Ord CLabel where compare (IdLabel a1 b1 c1) (IdLabel a2 b2 c2) = compare a1 a2 `thenCmp` compare b1 b2 `thenCmp` compare c1 c2 compare (CmmLabel a1 b1 c1 d1) (CmmLabel a2 b2 c2 d2) = compare a1 a2 `thenCmp` compare b1 b2 `thenCmp` compare c1 c2 `thenCmp` compare d1 d2 compare (RtsLabel a1) (RtsLabel a2) = compare a1 a2 compare (LocalBlockLabel u1) (LocalBlockLabel u2) = nonDetCmpUnique u1 u2 compare (ForeignLabel a1 b1 c1 d1) (ForeignLabel a2 b2 c2 d2) = compare a1 a2 `thenCmp` compare b1 b2 `thenCmp` compare c1 c2 `thenCmp` compare d1 d2 compare (AsmTempLabel u1) (AsmTempLabel u2) = nonDetCmpUnique u1 u2 compare (AsmTempDerivedLabel a1 b1) (AsmTempDerivedLabel a2 b2) = compare a1 a2 `thenCmp` compare b1 b2 compare (StringLitLabel u1) (StringLitLabel u2) = nonDetCmpUnique u1 u2 compare (CC_Label a1) (CC_Label a2) = compare a1 a2 compare (CCS_Label a1) (CCS_Label a2) = compare a1 a2 compare (DynamicLinkerLabel a1 b1) (DynamicLinkerLabel a2 b2) = compare a1 a2 `thenCmp` compare b1 b2 compare PicBaseLabel PicBaseLabel = EQ compare (DeadStripPreventer a1) (DeadStripPreventer a2) = compare a1 a2 compare (HpcTicksLabel a1) (HpcTicksLabel a2) = compare a1 a2 compare (SRTLabel u1) (SRTLabel u2) = nonDetCmpUnique u1 u2 compare (LargeBitmapLabel u1) (LargeBitmapLabel u2) = nonDetCmpUnique u1 u2 compare IdLabel{} _ = LT compare _ IdLabel{} = GT compare CmmLabel{} _ = LT compare _ CmmLabel{} = GT compare RtsLabel{} _ = LT compare _ RtsLabel{} = GT compare LocalBlockLabel{} _ = LT compare _ LocalBlockLabel{} = GT compare ForeignLabel{} _ = LT compare _ ForeignLabel{} = GT compare AsmTempLabel{} _ = LT compare _ AsmTempLabel{} = GT compare AsmTempDerivedLabel{} _ = LT compare _ AsmTempDerivedLabel{} = GT compare StringLitLabel{} _ = LT compare _ StringLitLabel{} = GT compare CC_Label{} _ = LT compare _ CC_Label{} = GT compare CCS_Label{} _ = LT compare _ CCS_Label{} = GT compare DynamicLinkerLabel{} _ = LT compare _ DynamicLinkerLabel{} = GT compare PicBaseLabel{} _ = LT compare _ PicBaseLabel{} = GT compare DeadStripPreventer{} _ = LT compare _ DeadStripPreventer{} = GT compare HpcTicksLabel{} _ = LT compare _ HpcTicksLabel{} = GT compare SRTLabel{} _ = LT compare _ SRTLabel{} = GT -- | Record where a foreign label is stored. data ForeignLabelSource -- | Label is in a named package = ForeignLabelInPackage UnitId -- | 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". | ForeignLabelInExternalPackage -- | 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. | ForeignLabelInThisPackage deriving (Eq, Ord) -- | 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. -- pprDebugCLabel :: CLabel -> SDoc pprDebugCLabel lbl = case lbl of IdLabel _ _ info-> ppr lbl <> (parens $ text "IdLabel" <> whenPprDebug (text ":" <> text (show info))) CmmLabel pkg _ext _name _info -> ppr lbl <> (parens $ text "CmmLabel" <+> ppr pkg) RtsLabel{} -> ppr lbl <> (parens $ text "RtsLabel") ForeignLabel _name mSuffix src funOrData -> ppr lbl <> (parens $ text "ForeignLabel" <+> ppr mSuffix <+> ppr src <+> ppr funOrData) _ -> ppr lbl <> (parens $ text "other CLabel") data IdLabelInfo = Closure -- ^ Label for closure | InfoTable -- ^ Info tables for closures; always read-only | Entry -- ^ Entry point | Slow -- ^ Slow entry point | LocalInfoTable -- ^ Like InfoTable but not externally visible | LocalEntry -- ^ Like Entry but not externally visible | RednCounts -- ^ Label of place to keep Ticky-ticky info for this Id | ConEntry -- ^ Constructor entry point | ConInfoTable -- ^ Corresponding info table | ClosureTable -- ^ Table of closures for Enum tycons | Bytes -- ^ Content of a string literal. See -- Note [Bytes label]. | BlockInfoTable -- ^ Like LocalInfoTable but for a proc-point block -- instead of a closure entry-point. -- See Note [Proc-point local block entry-point]. deriving (Eq, Ord, Show) data RtsLabelInfo = RtsSelectorInfoTable Bool{-updatable-} Int{-offset-} -- ^ Selector thunks | RtsSelectorEntry Bool{-updatable-} Int{-offset-} | RtsApInfoTable Bool{-updatable-} Int{-arity-} -- ^ AP thunks | RtsApEntry Bool{-updatable-} Int{-arity-} | RtsPrimOp PrimOp | RtsApFast FastString -- ^ _fast versions of generic apply | RtsSlowFastTickyCtr String deriving (Eq, Ord) -- NOTE: Eq on PtrString compares the pointer only, so this isn't -- a real equality. -- | What type of Cmm label we're dealing with. -- Determines the suffix appended to the name when a CLabel.CmmLabel -- is pretty printed. data CmmLabelInfo = CmmInfo -- ^ misc rts info tables, suffix _info | CmmEntry -- ^ misc rts entry points, suffix _entry | CmmRetInfo -- ^ misc rts ret info tables, suffix _info | CmmRet -- ^ misc rts return points, suffix _ret | CmmData -- ^ misc rts data bits, eg CHARLIKE_closure | CmmCode -- ^ misc rts code | CmmClosure -- ^ closures eg CHARLIKE_closure | CmmPrimCall -- ^ a prim call to some hand written Cmm code deriving (Eq, Ord) data DynamicLinkerLabelInfo = CodeStub -- MachO: Lfoo$stub, ELF: foo@plt | SymbolPtr -- MachO: Lfoo$non_lazy_ptr, Windows: __imp_foo | GotSymbolPtr -- ELF: foo@got | GotSymbolOffset -- ELF: foo@gotoff deriving (Eq, Ord) -- ----------------------------------------------------------------------------- -- Constructing CLabels -- ----------------------------------------------------------------------------- -- Constructing IdLabels -- These are always local: mkSRTLabel :: Unique -> CLabel mkSRTLabel u = SRTLabel u mkRednCountsLabel :: Name -> CLabel mkRednCountsLabel name = IdLabel name NoCafRefs RednCounts -- Note [ticky for LNE] -- These have local & (possibly) external variants: mkLocalClosureLabel :: Name -> CafInfo -> CLabel mkLocalInfoTableLabel :: Name -> CafInfo -> CLabel mkLocalClosureTableLabel :: Name -> CafInfo -> CLabel mkLocalClosureLabel name c = IdLabel name c Closure mkLocalInfoTableLabel name c = IdLabel name c LocalInfoTable mkLocalClosureTableLabel name c = IdLabel name c ClosureTable mkClosureLabel :: Name -> CafInfo -> CLabel mkInfoTableLabel :: Name -> CafInfo -> CLabel mkEntryLabel :: Name -> CafInfo -> CLabel mkClosureTableLabel :: Name -> CafInfo -> CLabel mkConInfoTableLabel :: Name -> CafInfo -> CLabel mkBytesLabel :: Name -> CLabel mkClosureLabel name c = IdLabel name c Closure mkInfoTableLabel name c = IdLabel name c InfoTable mkEntryLabel name c = IdLabel name c Entry mkClosureTableLabel name c = IdLabel name c ClosureTable mkConInfoTableLabel name c = IdLabel name c ConInfoTable mkBytesLabel name = IdLabel name NoCafRefs Bytes mkBlockInfoTableLabel :: Name -> CafInfo -> CLabel mkBlockInfoTableLabel name c = IdLabel name c BlockInfoTable -- See Note [Proc-point local block entry-point]. -- Constructing Cmm Labels mkDirty_MUT_VAR_Label, mkNonmovingWriteBarrierEnabledLabel, mkUpdInfoLabel, mkBHUpdInfoLabel, mkIndStaticInfoLabel, mkMainCapabilityLabel, mkMAP_FROZEN_CLEAN_infoLabel, mkMAP_FROZEN_DIRTY_infoLabel, mkMAP_DIRTY_infoLabel, mkArrWords_infoLabel, mkTopTickyCtrLabel, mkCAFBlackHoleInfoTableLabel, mkSMAP_FROZEN_CLEAN_infoLabel, mkSMAP_FROZEN_DIRTY_infoLabel, mkSMAP_DIRTY_infoLabel, mkBadAlignmentLabel :: CLabel mkDirty_MUT_VAR_Label = mkForeignLabel (fsLit "dirty_MUT_VAR") Nothing ForeignLabelInExternalPackage IsFunction mkNonmovingWriteBarrierEnabledLabel = CmmLabel rtsUnitId (NeedExternDecl False) (fsLit "nonmoving_write_barrier_enabled") CmmData mkUpdInfoLabel = CmmLabel rtsUnitId (NeedExternDecl False) (fsLit "stg_upd_frame") CmmInfo mkBHUpdInfoLabel = CmmLabel rtsUnitId (NeedExternDecl False) (fsLit "stg_bh_upd_frame" ) CmmInfo mkIndStaticInfoLabel = CmmLabel rtsUnitId (NeedExternDecl False) (fsLit "stg_IND_STATIC") CmmInfo mkMainCapabilityLabel = CmmLabel rtsUnitId (NeedExternDecl False) (fsLit "MainCapability") CmmData mkMAP_FROZEN_CLEAN_infoLabel = CmmLabel rtsUnitId (NeedExternDecl False) (fsLit "stg_MUT_ARR_PTRS_FROZEN_CLEAN") CmmInfo mkMAP_FROZEN_DIRTY_infoLabel = CmmLabel rtsUnitId (NeedExternDecl False) (fsLit "stg_MUT_ARR_PTRS_FROZEN_DIRTY") CmmInfo mkMAP_DIRTY_infoLabel = CmmLabel rtsUnitId (NeedExternDecl False) (fsLit "stg_MUT_ARR_PTRS_DIRTY") CmmInfo mkTopTickyCtrLabel = CmmLabel rtsUnitId (NeedExternDecl False) (fsLit "top_ct") CmmData mkCAFBlackHoleInfoTableLabel = CmmLabel rtsUnitId (NeedExternDecl False) (fsLit "stg_CAF_BLACKHOLE") CmmInfo mkArrWords_infoLabel = CmmLabel rtsUnitId (NeedExternDecl False) (fsLit "stg_ARR_WORDS") CmmInfo mkSMAP_FROZEN_CLEAN_infoLabel = CmmLabel rtsUnitId (NeedExternDecl False) (fsLit "stg_SMALL_MUT_ARR_PTRS_FROZEN_CLEAN") CmmInfo mkSMAP_FROZEN_DIRTY_infoLabel = CmmLabel rtsUnitId (NeedExternDecl False) (fsLit "stg_SMALL_MUT_ARR_PTRS_FROZEN_DIRTY") CmmInfo mkSMAP_DIRTY_infoLabel = CmmLabel rtsUnitId (NeedExternDecl False) (fsLit "stg_SMALL_MUT_ARR_PTRS_DIRTY") CmmInfo mkBadAlignmentLabel = CmmLabel rtsUnitId (NeedExternDecl False) (fsLit "stg_badAlignment") CmmEntry mkSRTInfoLabel :: Int -> CLabel mkSRTInfoLabel n = CmmLabel rtsUnitId (NeedExternDecl False) lbl CmmInfo where lbl = case n of 1 -> fsLit "stg_SRT_1" 2 -> fsLit "stg_SRT_2" 3 -> fsLit "stg_SRT_3" 4 -> fsLit "stg_SRT_4" 5 -> fsLit "stg_SRT_5" 6 -> fsLit "stg_SRT_6" 7 -> fsLit "stg_SRT_7" 8 -> fsLit "stg_SRT_8" 9 -> fsLit "stg_SRT_9" 10 -> fsLit "stg_SRT_10" 11 -> fsLit "stg_SRT_11" 12 -> fsLit "stg_SRT_12" 13 -> fsLit "stg_SRT_13" 14 -> fsLit "stg_SRT_14" 15 -> fsLit "stg_SRT_15" 16 -> fsLit "stg_SRT_16" _ -> panic "mkSRTInfoLabel" ----- mkCmmInfoLabel, mkCmmEntryLabel, mkCmmRetInfoLabel, mkCmmRetLabel, mkCmmCodeLabel, mkCmmClosureLabel :: UnitId -> FastString -> CLabel mkCmmDataLabel :: UnitId -> NeedExternDecl -> FastString -> CLabel mkRtsCmmDataLabel :: FastString -> CLabel mkCmmInfoLabel pkg str = CmmLabel pkg (NeedExternDecl True) str CmmInfo mkCmmEntryLabel pkg str = CmmLabel pkg (NeedExternDecl True) str CmmEntry mkCmmRetInfoLabel pkg str = CmmLabel pkg (NeedExternDecl True) str CmmRetInfo mkCmmRetLabel pkg str = CmmLabel pkg (NeedExternDecl True) str CmmRet mkCmmCodeLabel pkg str = CmmLabel pkg (NeedExternDecl True) str CmmCode mkCmmClosureLabel pkg str = CmmLabel pkg (NeedExternDecl True) str CmmClosure mkCmmDataLabel pkg ext str = CmmLabel pkg ext str CmmData mkRtsCmmDataLabel str = CmmLabel rtsUnitId (NeedExternDecl False) str CmmData -- RTS symbols don't need "GHC.CmmToC" to -- generate \"extern\" declaration (they are -- exposed via includes/Stg.h) mkLocalBlockLabel :: Unique -> CLabel mkLocalBlockLabel u = LocalBlockLabel u -- Constructing RtsLabels mkRtsPrimOpLabel :: PrimOp -> CLabel mkRtsPrimOpLabel primop = RtsLabel (RtsPrimOp primop) mkSelectorInfoLabel :: Bool -> Int -> CLabel mkSelectorEntryLabel :: Bool -> Int -> CLabel mkSelectorInfoLabel upd off = RtsLabel (RtsSelectorInfoTable upd off) mkSelectorEntryLabel upd off = RtsLabel (RtsSelectorEntry upd off) mkApInfoTableLabel :: Bool -> Int -> CLabel mkApEntryLabel :: Bool -> Int -> CLabel mkApInfoTableLabel upd off = RtsLabel (RtsApInfoTable upd off) mkApEntryLabel upd off = RtsLabel (RtsApEntry upd off) -- A call to some primitive hand written Cmm code mkPrimCallLabel :: PrimCall -> CLabel mkPrimCallLabel (PrimCall str pkg) = CmmLabel pkg (NeedExternDecl True) str CmmPrimCall -- Constructing ForeignLabels -- | Make a foreign label mkForeignLabel :: FastString -- name -> Maybe Int -- size prefix -> ForeignLabelSource -- what package it's in -> FunctionOrData -> CLabel mkForeignLabel = ForeignLabel -- | Update the label size field in a ForeignLabel addLabelSize :: CLabel -> Int -> CLabel addLabelSize (ForeignLabel str _ src fod) sz = ForeignLabel str (Just sz) src fod addLabelSize label _ = label -- | Whether label is a top-level string literal isBytesLabel :: CLabel -> Bool isBytesLabel (IdLabel _ _ Bytes) = True isBytesLabel _lbl = False -- | Whether label is a non-haskell label (defined in C code) isForeignLabel :: CLabel -> Bool isForeignLabel (ForeignLabel _ _ _ _) = True isForeignLabel _lbl = False -- | Whether label is a static closure label (can come from haskell or cmm) isStaticClosureLabel :: CLabel -> Bool -- Closure defined in haskell (.hs) isStaticClosureLabel (IdLabel _ _ Closure) = True -- Closure defined in cmm isStaticClosureLabel (CmmLabel _ _ _ CmmClosure) = True isStaticClosureLabel _lbl = False -- | Whether label is a .rodata label isSomeRODataLabel :: CLabel -> Bool -- info table defined in haskell (.hs) isSomeRODataLabel (IdLabel _ _ ClosureTable) = True isSomeRODataLabel (IdLabel _ _ ConInfoTable) = True isSomeRODataLabel (IdLabel _ _ InfoTable) = True isSomeRODataLabel (IdLabel _ _ LocalInfoTable) = True isSomeRODataLabel (IdLabel _ _ BlockInfoTable) = True -- info table defined in cmm (.cmm) isSomeRODataLabel (CmmLabel _ _ _ CmmInfo) = True isSomeRODataLabel _lbl = False -- | Whether label is points to some kind of info table isInfoTableLabel :: CLabel -> Bool isInfoTableLabel (IdLabel _ _ InfoTable) = True isInfoTableLabel (IdLabel _ _ LocalInfoTable) = True isInfoTableLabel (IdLabel _ _ ConInfoTable) = True isInfoTableLabel (IdLabel _ _ BlockInfoTable) = True isInfoTableLabel _ = False -- | Whether label is points to constructor info table isConInfoTableLabel :: CLabel -> Bool isConInfoTableLabel (IdLabel _ _ ConInfoTable) = True isConInfoTableLabel _ = False -- | Get the label size field from a ForeignLabel foreignLabelStdcallInfo :: CLabel -> Maybe Int foreignLabelStdcallInfo (ForeignLabel _ info _ _) = info foreignLabelStdcallInfo _lbl = Nothing -- Constructing Large*Labels mkBitmapLabel :: Unique -> CLabel mkBitmapLabel uniq = LargeBitmapLabel uniq -- Constructing Cost Center Labels mkCCLabel :: CostCentre -> CLabel mkCCSLabel :: CostCentreStack -> CLabel mkCCLabel cc = CC_Label cc mkCCSLabel ccs = CCS_Label ccs mkRtsApFastLabel :: FastString -> CLabel mkRtsApFastLabel str = RtsLabel (RtsApFast str) mkRtsSlowFastTickyCtrLabel :: String -> CLabel mkRtsSlowFastTickyCtrLabel pat = RtsLabel (RtsSlowFastTickyCtr pat) -- Constructing Code Coverage Labels mkHpcTicksLabel :: Module -> CLabel mkHpcTicksLabel = HpcTicksLabel -- Constructing labels used for dynamic linking mkDynamicLinkerLabel :: DynamicLinkerLabelInfo -> CLabel -> CLabel mkDynamicLinkerLabel = DynamicLinkerLabel dynamicLinkerLabelInfo :: CLabel -> Maybe (DynamicLinkerLabelInfo, CLabel) dynamicLinkerLabelInfo (DynamicLinkerLabel info lbl) = Just (info, lbl) dynamicLinkerLabelInfo _ = Nothing mkPicBaseLabel :: CLabel mkPicBaseLabel = PicBaseLabel -- Constructing miscellaneous other labels mkDeadStripPreventer :: CLabel -> CLabel mkDeadStripPreventer lbl = DeadStripPreventer lbl mkStringLitLabel :: Unique -> CLabel mkStringLitLabel = StringLitLabel mkAsmTempLabel :: Uniquable a => a -> CLabel mkAsmTempLabel a = AsmTempLabel (getUnique a) mkAsmTempDerivedLabel :: CLabel -> FastString -> CLabel mkAsmTempDerivedLabel = AsmTempDerivedLabel mkAsmTempEndLabel :: CLabel -> CLabel mkAsmTempEndLabel l = mkAsmTempDerivedLabel l (fsLit "_end") -- | Construct a label for a DWARF Debug Information Entity (DIE) -- describing another symbol. mkAsmTempDieLabel :: CLabel -> CLabel mkAsmTempDieLabel l = mkAsmTempDerivedLabel l (fsLit "_die") -- ----------------------------------------------------------------------------- -- Convert between different kinds of label toClosureLbl :: CLabel -> CLabel toClosureLbl (IdLabel n c _) = IdLabel n c Closure toClosureLbl (CmmLabel m ext str _) = CmmLabel m ext str CmmClosure toClosureLbl l = pprPanic "toClosureLbl" (ppr l) toSlowEntryLbl :: CLabel -> CLabel toSlowEntryLbl (IdLabel n _ BlockInfoTable) = pprPanic "toSlowEntryLbl" (ppr n) toSlowEntryLbl (IdLabel n c _) = IdLabel n c Slow toSlowEntryLbl l = pprPanic "toSlowEntryLbl" (ppr l) toEntryLbl :: CLabel -> CLabel toEntryLbl (IdLabel n c LocalInfoTable) = IdLabel n c LocalEntry toEntryLbl (IdLabel n c ConInfoTable) = IdLabel n c ConEntry toEntryLbl (IdLabel n _ BlockInfoTable) = mkLocalBlockLabel (nameUnique n) -- See Note [Proc-point local block entry-point]. toEntryLbl (IdLabel n c _) = IdLabel n c Entry toEntryLbl (CmmLabel m ext str CmmInfo) = CmmLabel m ext str CmmEntry toEntryLbl (CmmLabel m ext str CmmRetInfo) = CmmLabel m ext str CmmRet toEntryLbl l = pprPanic "toEntryLbl" (ppr l) toInfoLbl :: CLabel -> CLabel toInfoLbl (IdLabel n c LocalEntry) = IdLabel n c LocalInfoTable toInfoLbl (IdLabel n c ConEntry) = IdLabel n c ConInfoTable toInfoLbl (IdLabel n c _) = IdLabel n c InfoTable toInfoLbl (CmmLabel m ext str CmmEntry)= CmmLabel m ext str CmmInfo toInfoLbl (CmmLabel m ext str CmmRet) = CmmLabel m ext str CmmRetInfo toInfoLbl l = pprPanic "CLabel.toInfoLbl" (ppr l) hasHaskellName :: CLabel -> Maybe Name hasHaskellName (IdLabel n _ _) = Just n hasHaskellName _ = Nothing -- ----------------------------------------------------------------------------- -- Does a CLabel's referent itself refer to a CAF? hasCAF :: CLabel -> Bool hasCAF (IdLabel _ _ RednCounts) = False -- Note [ticky for LNE] hasCAF (IdLabel _ MayHaveCafRefs _) = True hasCAF _ = False -- Note [ticky for LNE] -- ~~~~~~~~~~~~~~~~~~~~~ -- Until 14 Feb 2013, every ticky counter was associated with a -- closure. Thus, ticky labels used IdLabel. It is odd that -- CmmBuildInfoTables.cafTransfers would consider such a ticky label -- reason to add the name to the CAFEnv (and thus eventually the SRT), -- but it was harmless because the ticky was only used if the closure -- was also. -- -- Since we now have ticky counters for LNEs, it is no longer the case -- that every ticky counter has an actual closure. So I changed the -- generation of ticky counters' CLabels to not result in their -- associated id ending up in the SRT. -- -- NB IdLabel is still appropriate for ticky ids (as opposed to -- CmmLabel) because the LNE's counter is still related to an .hs Id, -- that Id just isn't for a proper closure. -- ----------------------------------------------------------------------------- -- Does a CLabel need declaring before use or not? -- -- See wiki:commentary/compiler/backends/ppr-c#prototypes needsCDecl :: CLabel -> Bool -- False <=> it's pre-declared; don't bother -- don't bother declaring Bitmap labels, we always make sure -- they are defined before use. needsCDecl (SRTLabel _) = True needsCDecl (LargeBitmapLabel _) = False needsCDecl (IdLabel _ _ _) = True needsCDecl (LocalBlockLabel _) = True needsCDecl (StringLitLabel _) = False needsCDecl (AsmTempLabel _) = False needsCDecl (AsmTempDerivedLabel _ _) = False needsCDecl (RtsLabel _) = False needsCDecl (CmmLabel pkgId (NeedExternDecl external) _ _) -- local labels mustn't have it | not external = False -- Prototypes for labels defined in the runtime system are imported -- into HC files via includes/Stg.h. | pkgId == rtsUnitId = False -- For other labels we inline one into the HC file directly. | otherwise = True needsCDecl l@(ForeignLabel{}) = not (isMathFun l) needsCDecl (CC_Label _) = True needsCDecl (CCS_Label _) = True needsCDecl (HpcTicksLabel _) = True needsCDecl (DynamicLinkerLabel {}) = panic "needsCDecl DynamicLinkerLabel" needsCDecl PicBaseLabel = panic "needsCDecl PicBaseLabel" needsCDecl (DeadStripPreventer {}) = panic "needsCDecl DeadStripPreventer" -- | If a label is a local block label then return just its 'BlockId', otherwise -- 'Nothing'. maybeLocalBlockLabel :: CLabel -> Maybe BlockId maybeLocalBlockLabel (LocalBlockLabel uq) = Just $ mkBlockId uq maybeLocalBlockLabel _ = Nothing -- | 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. isMathFun :: CLabel -> Bool isMathFun (ForeignLabel fs _ _ _) = fs `elementOfUniqSet` math_funs isMathFun _ = False math_funs :: UniqSet FastString math_funs = mkUniqSet [ -- _ISOC99_SOURCE (fsLit "acos"), (fsLit "acosf"), (fsLit "acosh"), (fsLit "acoshf"), (fsLit "acoshl"), (fsLit "acosl"), (fsLit "asin"), (fsLit "asinf"), (fsLit "asinl"), (fsLit "asinh"), (fsLit "asinhf"), (fsLit "asinhl"), (fsLit "atan"), (fsLit "atanf"), (fsLit "atanl"), (fsLit "atan2"), (fsLit "atan2f"), (fsLit "atan2l"), (fsLit "atanh"), (fsLit "atanhf"), (fsLit "atanhl"), (fsLit "cbrt"), (fsLit "cbrtf"), (fsLit "cbrtl"), (fsLit "ceil"), (fsLit "ceilf"), (fsLit "ceill"), (fsLit "copysign"), (fsLit "copysignf"), (fsLit "copysignl"), (fsLit "cos"), (fsLit "cosf"), (fsLit "cosl"), (fsLit "cosh"), (fsLit "coshf"), (fsLit "coshl"), (fsLit "erf"), (fsLit "erff"), (fsLit "erfl"), (fsLit "erfc"), (fsLit "erfcf"), (fsLit "erfcl"), (fsLit "exp"), (fsLit "expf"), (fsLit "expl"), (fsLit "exp2"), (fsLit "exp2f"), (fsLit "exp2l"), (fsLit "expm1"), (fsLit "expm1f"), (fsLit "expm1l"), (fsLit "fabs"), (fsLit "fabsf"), (fsLit "fabsl"), (fsLit "fdim"), (fsLit "fdimf"), (fsLit "fdiml"), (fsLit "floor"), (fsLit "floorf"), (fsLit "floorl"), (fsLit "fma"), (fsLit "fmaf"), (fsLit "fmal"), (fsLit "fmax"), (fsLit "fmaxf"), (fsLit "fmaxl"), (fsLit "fmin"), (fsLit "fminf"), (fsLit "fminl"), (fsLit "fmod"), (fsLit "fmodf"), (fsLit "fmodl"), (fsLit "frexp"), (fsLit "frexpf"), (fsLit "frexpl"), (fsLit "hypot"), (fsLit "hypotf"), (fsLit "hypotl"), (fsLit "ilogb"), (fsLit "ilogbf"), (fsLit "ilogbl"), (fsLit "ldexp"), (fsLit "ldexpf"), (fsLit "ldexpl"), (fsLit "lgamma"), (fsLit "lgammaf"), (fsLit "lgammal"), (fsLit "llrint"), (fsLit "llrintf"), (fsLit "llrintl"), (fsLit "llround"), (fsLit "llroundf"), (fsLit "llroundl"), (fsLit "log"), (fsLit "logf"), (fsLit "logl"), (fsLit "log10l"), (fsLit "log10"), (fsLit "log10f"), (fsLit "log1pl"), (fsLit "log1p"), (fsLit "log1pf"), (fsLit "log2"), (fsLit "log2f"), (fsLit "log2l"), (fsLit "logb"), (fsLit "logbf"), (fsLit "logbl"), (fsLit "lrint"), (fsLit "lrintf"), (fsLit "lrintl"), (fsLit "lround"), (fsLit "lroundf"), (fsLit "lroundl"), (fsLit "modf"), (fsLit "modff"), (fsLit "modfl"), (fsLit "nan"), (fsLit "nanf"), (fsLit "nanl"), (fsLit "nearbyint"), (fsLit "nearbyintf"), (fsLit "nearbyintl"), (fsLit "nextafter"), (fsLit "nextafterf"), (fsLit "nextafterl"), (fsLit "nexttoward"), (fsLit "nexttowardf"), (fsLit "nexttowardl"), (fsLit "pow"), (fsLit "powf"), (fsLit "powl"), (fsLit "remainder"), (fsLit "remainderf"), (fsLit "remainderl"), (fsLit "remquo"), (fsLit "remquof"), (fsLit "remquol"), (fsLit "rint"), (fsLit "rintf"), (fsLit "rintl"), (fsLit "round"), (fsLit "roundf"), (fsLit "roundl"), (fsLit "scalbln"), (fsLit "scalblnf"), (fsLit "scalblnl"), (fsLit "scalbn"), (fsLit "scalbnf"), (fsLit "scalbnl"), (fsLit "sin"), (fsLit "sinf"), (fsLit "sinl"), (fsLit "sinh"), (fsLit "sinhf"), (fsLit "sinhl"), (fsLit "sqrt"), (fsLit "sqrtf"), (fsLit "sqrtl"), (fsLit "tan"), (fsLit "tanf"), (fsLit "tanl"), (fsLit "tanh"), (fsLit "tanhf"), (fsLit "tanhl"), (fsLit "tgamma"), (fsLit "tgammaf"), (fsLit "tgammal"), (fsLit "trunc"), (fsLit "truncf"), (fsLit "truncl"), -- ISO C 99 also defines these function-like macros in math.h: -- fpclassify, isfinite, isinf, isnormal, signbit, isgreater, -- isgreaterequal, isless, islessequal, islessgreater, isunordered -- additional symbols from _BSD_SOURCE (fsLit "drem"), (fsLit "dremf"), (fsLit "dreml"), (fsLit "finite"), (fsLit "finitef"), (fsLit "finitel"), (fsLit "gamma"), (fsLit "gammaf"), (fsLit "gammal"), (fsLit "isinf"), (fsLit "isinff"), (fsLit "isinfl"), (fsLit "isnan"), (fsLit "isnanf"), (fsLit "isnanl"), (fsLit "j0"), (fsLit "j0f"), (fsLit "j0l"), (fsLit "j1"), (fsLit "j1f"), (fsLit "j1l"), (fsLit "jn"), (fsLit "jnf"), (fsLit "jnl"), (fsLit "lgamma_r"), (fsLit "lgammaf_r"), (fsLit "lgammal_r"), (fsLit "scalb"), (fsLit "scalbf"), (fsLit "scalbl"), (fsLit "significand"), (fsLit "significandf"), (fsLit "significandl"), (fsLit "y0"), (fsLit "y0f"), (fsLit "y0l"), (fsLit "y1"), (fsLit "y1f"), (fsLit "y1l"), (fsLit "yn"), (fsLit "ynf"), (fsLit "ynl"), -- These functions are described in IEEE Std 754-2008 - -- Standard for Floating-Point Arithmetic and ISO/IEC TS 18661 (fsLit "nextup"), (fsLit "nextupf"), (fsLit "nextupl"), (fsLit "nextdown"), (fsLit "nextdownf"), (fsLit "nextdownl") ] -- ----------------------------------------------------------------------------- -- | 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. externallyVisibleCLabel :: CLabel -> Bool -- not C "static" externallyVisibleCLabel (StringLitLabel _) = False externallyVisibleCLabel (AsmTempLabel _) = False externallyVisibleCLabel (AsmTempDerivedLabel _ _)= False externallyVisibleCLabel (RtsLabel _) = True externallyVisibleCLabel (LocalBlockLabel _) = False externallyVisibleCLabel (CmmLabel _ _ _ _) = True externallyVisibleCLabel (ForeignLabel{}) = True externallyVisibleCLabel (IdLabel name _ info) = isExternalName name && externallyVisibleIdLabel info externallyVisibleCLabel (CC_Label _) = True externallyVisibleCLabel (CCS_Label _) = True externallyVisibleCLabel (DynamicLinkerLabel _ _) = False externallyVisibleCLabel (HpcTicksLabel _) = True externallyVisibleCLabel (LargeBitmapLabel _) = False externallyVisibleCLabel (SRTLabel _) = False externallyVisibleCLabel (PicBaseLabel {}) = panic "externallyVisibleCLabel PicBaseLabel" externallyVisibleCLabel (DeadStripPreventer {}) = panic "externallyVisibleCLabel DeadStripPreventer" externallyVisibleIdLabel :: IdLabelInfo -> Bool externallyVisibleIdLabel LocalInfoTable = False externallyVisibleIdLabel LocalEntry = False externallyVisibleIdLabel BlockInfoTable = False externallyVisibleIdLabel _ = True -- ----------------------------------------------------------------------------- -- Finding the "type" of a CLabel -- For generating correct types in label declarations: data CLabelType = CodeLabel -- Address of some executable instructions | DataLabel -- Address of data, not a GC ptr | GcPtrLabel -- Address of a (presumably static) GC object isCFunctionLabel :: CLabel -> Bool isCFunctionLabel lbl = case labelType lbl of CodeLabel -> True _other -> False isGcPtrLabel :: CLabel -> Bool isGcPtrLabel lbl = case labelType lbl of GcPtrLabel -> True _other -> False -- | Work out the general type of data at the address of this label -- whether it be code, data, or static GC object. labelType :: CLabel -> CLabelType labelType (IdLabel _ _ info) = idInfoLabelType info labelType (CmmLabel _ _ _ CmmData) = DataLabel labelType (CmmLabel _ _ _ CmmClosure) = GcPtrLabel labelType (CmmLabel _ _ _ CmmCode) = CodeLabel labelType (CmmLabel _ _ _ CmmInfo) = DataLabel labelType (CmmLabel _ _ _ CmmEntry) = CodeLabel labelType (CmmLabel _ _ _ CmmPrimCall) = CodeLabel labelType (CmmLabel _ _ _ CmmRetInfo) = DataLabel labelType (CmmLabel _ _ _ CmmRet) = CodeLabel labelType (RtsLabel (RtsSelectorInfoTable _ _)) = DataLabel labelType (RtsLabel (RtsApInfoTable _ _)) = DataLabel labelType (RtsLabel (RtsApFast _)) = CodeLabel labelType (RtsLabel _) = DataLabel labelType (LocalBlockLabel _) = CodeLabel labelType (SRTLabel _) = DataLabel labelType (ForeignLabel _ _ _ IsFunction) = CodeLabel labelType (ForeignLabel _ _ _ IsData) = DataLabel labelType (AsmTempLabel _) = panic "labelType(AsmTempLabel)" labelType (AsmTempDerivedLabel _ _) = panic "labelType(AsmTempDerivedLabel)" labelType (StringLitLabel _) = DataLabel labelType (CC_Label _) = DataLabel labelType (CCS_Label _) = DataLabel labelType (DynamicLinkerLabel _ _) = DataLabel -- Is this right? labelType PicBaseLabel = DataLabel labelType (DeadStripPreventer _) = DataLabel labelType (HpcTicksLabel _) = DataLabel labelType (LargeBitmapLabel _) = DataLabel idInfoLabelType :: IdLabelInfo -> CLabelType idInfoLabelType info = case info of InfoTable -> DataLabel LocalInfoTable -> DataLabel BlockInfoTable -> DataLabel Closure -> GcPtrLabel ConInfoTable -> DataLabel ClosureTable -> DataLabel RednCounts -> DataLabel Bytes -> DataLabel _ -> CodeLabel -- ----------------------------------------------------------------------------- -- | 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. isLocalCLabel :: Module -> CLabel -> Bool isLocalCLabel this_mod lbl = case lbl of IdLabel name _ _ | isInternalName name -> True | otherwise -> nameModule name == this_mod LocalBlockLabel _ -> True _ -> False -- ----------------------------------------------------------------------------- -- | 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. labelDynamic :: DynFlags -> Module -> CLabel -> Bool labelDynamic dflags this_mod lbl = case lbl of -- is the RTS in a DLL or not? RtsLabel _ -> externalDynamicRefs && (this_pkg /= rtsUnitId) IdLabel n _ _ -> isDllName dflags this_mod n -- When compiling in the "dyn" way, each package is to be linked into -- its own shared library. CmmLabel pkg _ _ _ | os == OSMinGW32 -> externalDynamicRefs && (this_pkg /= pkg) | otherwise -> gopt Opt_ExternalDynamicRefs dflags LocalBlockLabel _ -> False ForeignLabel _ _ source _ -> if os == OSMinGW32 then case source of -- Foreign label is in some un-named foreign package (or DLL). ForeignLabelInExternalPackage -> True -- Foreign label is linked into the same package as the -- source file currently being compiled. ForeignLabelInThisPackage -> False -- Foreign label is in some named package. -- When compiling in the "dyn" way, each package is to be -- linked into its own DLL. ForeignLabelInPackage pkgId -> externalDynamicRefs && (this_pkg /= pkgId) else -- On Mac OS X and on ELF platforms, false positives are OK, -- so we claim that all foreign imports come from dynamic -- libraries True CC_Label cc -> externalDynamicRefs && not (ccFromThisModule cc this_mod) -- CCS_Label always contains a CostCentre defined in the current module CCS_Label _ -> False HpcTicksLabel m -> externalDynamicRefs && this_mod /= m -- Note that DynamicLinkerLabels do NOT require dynamic linking themselves. _ -> False where externalDynamicRefs = gopt Opt_ExternalDynamicRefs dflags os = platformOS (targetPlatform dflags) this_pkg = moduleUnitId this_mod ----------------------------------------------------------------------------- -- Printing out CLabels. {- Convention: _ where is _ for external names and for internal names. is one of the following: info Info table srt Static reference table entry Entry code (function, closure) slow Slow entry code (if any) ret Direct return address vtbl Vector table _alt Case alternative (tag n) dflt Default case alternative btm Large bitmap vector closure Static closure con_entry Dynamic Constructor entry code con_info Dynamic Constructor info table static_entry Static Constructor entry code static_info Static Constructor info table sel_info Selector info table sel_entry Selector entry code cc Cost centre ccs Cost centre stack Many of these distinctions are only for documentation reasons. For example, _ret is only distinguished from _entry to make it easy to tell whether a code fragment is a return point or a closure/function entry. Note [Closure and info labels] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For a function 'foo, we have: foo_info : Points to the info table describing foo's closure (and entry code for foo with tables next to code) foo_closure : Static (no-free-var) closure only: points to the statically-allocated closure For a data constructor (such as Just or Nothing), we have: Just_con_info: Info table for the data constructor itself the first word of a heap-allocated Just Just_info: Info table for the *worker function*, an ordinary Haskell function of arity 1 that allocates a (Just x) box: Just = \x -> Just x Just_closure: The closure for this worker Nothing_closure: a statically allocated closure for Nothing Nothing_static_info: info table for Nothing_closure All these must be exported symbol, EXCEPT Just_info. We don't need to export this because in other modules we either have * A reference to 'Just'; use Just_closure * A saturated call 'Just x'; allocate using Just_con_info Not exporting these Just_info labels reduces the number of symbols somewhat. Note [Bytes label] ~~~~~~~~~~~~~~~~~~ For a top-level string literal 'foo', we have just one symbol 'foo_bytes', which points to a static data block containing the content of the literal. Note [Proc-point local block entry-points] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ A label for a proc-point local block entry-point has no "_entry" suffix. With `infoTblLbl` we derive an info table label from a proc-point block ID. If we convert such an info table label into an entry label we must produce the label without an "_entry" suffix. So an info table label records the fact that it was derived from a block ID in `IdLabelInfo` as `BlockInfoTable`. The info table label and the local block label are both local labels and are not externally visible. -} instance Outputable CLabel where ppr c = sdocWithDynFlags $ \dynFlags -> pprCLabel dynFlags c pprCLabel :: DynFlags -> CLabel -> SDoc pprCLabel _ (LocalBlockLabel u) = tempLabelPrefixOrUnderscore <> pprUniqueAlways u pprCLabel dynFlags (AsmTempLabel u) | not (platformUnregisterised $ targetPlatform dynFlags) = tempLabelPrefixOrUnderscore <> pprUniqueAlways u pprCLabel dynFlags (AsmTempDerivedLabel l suf) | platformMisc_ghcWithNativeCodeGen $ platformMisc dynFlags = ptext (asmTempLabelPrefix $ targetPlatform dynFlags) <> case l of AsmTempLabel u -> pprUniqueAlways u LocalBlockLabel u -> pprUniqueAlways u _other -> pprCLabel dynFlags l <> ftext suf pprCLabel dynFlags (DynamicLinkerLabel info lbl) | platformMisc_ghcWithNativeCodeGen $ platformMisc dynFlags = pprDynamicLinkerAsmLabel (targetPlatform dynFlags) info lbl pprCLabel dynFlags PicBaseLabel | platformMisc_ghcWithNativeCodeGen $ platformMisc dynFlags = text "1b" pprCLabel dynFlags (DeadStripPreventer lbl) | platformMisc_ghcWithNativeCodeGen $ platformMisc dynFlags = {- `lbl` can be temp one but we need to ensure that dsp label will stay in the final binary so we prepend non-temp prefix ("dsp_") and optional `_` (underscore) because this is how you mark non-temp symbols on some platforms (Darwin) -} maybe_underscore dynFlags $ text "dsp_" <> pprCLabel dynFlags lbl <> text "_dsp" pprCLabel dynFlags (StringLitLabel u) | platformMisc_ghcWithNativeCodeGen $ platformMisc dynFlags = pprUniqueAlways u <> ptext (sLit "_str") pprCLabel dynFlags lbl = getPprStyle $ \ sty -> if platformMisc_ghcWithNativeCodeGen (platformMisc dynFlags) && asmStyle sty then maybe_underscore dynFlags $ pprAsmCLbl (targetPlatform dynFlags) lbl else pprCLbl lbl maybe_underscore :: DynFlags -> SDoc -> SDoc maybe_underscore dynFlags doc = if platformMisc_leadingUnderscore $ platformMisc dynFlags then pp_cSEP <> doc else doc pprAsmCLbl :: Platform -> CLabel -> SDoc pprAsmCLbl platform (ForeignLabel fs (Just sz) _ _) | platformOS platform == OSMinGW32 -- In asm mode, we need to put the suffix on a stdcall ForeignLabel. -- (The C compiler does this itself). = ftext fs <> char '@' <> int sz pprAsmCLbl _ lbl = pprCLbl lbl pprCLbl :: CLabel -> SDoc pprCLbl (StringLitLabel u) = pprUniqueAlways u <> text "_str" pprCLbl (SRTLabel u) = tempLabelPrefixOrUnderscore <> pprUniqueAlways u <> pp_cSEP <> text "srt" pprCLbl (LargeBitmapLabel u) = tempLabelPrefixOrUnderscore <> char 'b' <> pprUniqueAlways u <> pp_cSEP <> text "btm" -- Some bitsmaps for tuple constructors have a numeric tag (e.g. '7') -- until that gets resolved we'll just force them to start -- with a letter so the label will be legal assembly code. pprCLbl (CmmLabel _ _ str CmmCode) = ftext str pprCLbl (CmmLabel _ _ str CmmData) = ftext str pprCLbl (CmmLabel _ _ str CmmPrimCall) = ftext str pprCLbl (LocalBlockLabel u) = tempLabelPrefixOrUnderscore <> text "blk_" <> pprUniqueAlways u pprCLbl (RtsLabel (RtsApFast str)) = ftext str <> text "_fast" pprCLbl (RtsLabel (RtsSelectorInfoTable upd_reqd offset)) = sdocWithDynFlags $ \dflags -> ASSERT(offset >= 0 && offset <= mAX_SPEC_SELECTEE_SIZE dflags) hcat [text "stg_sel_", text (show offset), ptext (if upd_reqd then (sLit "_upd_info") else (sLit "_noupd_info")) ] pprCLbl (RtsLabel (RtsSelectorEntry upd_reqd offset)) = sdocWithDynFlags $ \dflags -> ASSERT(offset >= 0 && offset <= mAX_SPEC_SELECTEE_SIZE dflags) hcat [text "stg_sel_", text (show offset), ptext (if upd_reqd then (sLit "_upd_entry") else (sLit "_noupd_entry")) ] pprCLbl (RtsLabel (RtsApInfoTable upd_reqd arity)) = sdocWithDynFlags $ \dflags -> ASSERT(arity > 0 && arity <= mAX_SPEC_AP_SIZE dflags) hcat [text "stg_ap_", text (show arity), ptext (if upd_reqd then (sLit "_upd_info") else (sLit "_noupd_info")) ] pprCLbl (RtsLabel (RtsApEntry upd_reqd arity)) = sdocWithDynFlags $ \dflags -> ASSERT(arity > 0 && arity <= mAX_SPEC_AP_SIZE dflags) hcat [text "stg_ap_", text (show arity), ptext (if upd_reqd then (sLit "_upd_entry") else (sLit "_noupd_entry")) ] pprCLbl (CmmLabel _ _ fs CmmInfo) = ftext fs <> text "_info" pprCLbl (CmmLabel _ _ fs CmmEntry) = ftext fs <> text "_entry" pprCLbl (CmmLabel _ _ fs CmmRetInfo) = ftext fs <> text "_info" pprCLbl (CmmLabel _ _ fs CmmRet) = ftext fs <> text "_ret" pprCLbl (CmmLabel _ _ fs CmmClosure) = ftext fs <> text "_closure" pprCLbl (RtsLabel (RtsPrimOp primop)) = text "stg_" <> ppr primop pprCLbl (RtsLabel (RtsSlowFastTickyCtr pat)) = text "SLOW_CALL_fast_" <> text pat <> ptext (sLit "_ctr") pprCLbl (ForeignLabel str _ _ _) = ftext str pprCLbl (IdLabel name _cafs flavor) = internalNamePrefix name <> ppr name <> ppIdFlavor flavor pprCLbl (CC_Label cc) = ppr cc pprCLbl (CCS_Label ccs) = ppr ccs pprCLbl (HpcTicksLabel mod) = text "_hpc_tickboxes_" <> ppr mod <> ptext (sLit "_hpc") pprCLbl (AsmTempLabel {}) = panic "pprCLbl AsmTempLabel" pprCLbl (AsmTempDerivedLabel {})= panic "pprCLbl AsmTempDerivedLabel" pprCLbl (DynamicLinkerLabel {}) = panic "pprCLbl DynamicLinkerLabel" pprCLbl (PicBaseLabel {}) = panic "pprCLbl PicBaseLabel" pprCLbl (DeadStripPreventer {}) = panic "pprCLbl DeadStripPreventer" ppIdFlavor :: IdLabelInfo -> SDoc ppIdFlavor x = pp_cSEP <> text (case x of Closure -> "closure" InfoTable -> "info" LocalInfoTable -> "info" Entry -> "entry" LocalEntry -> "entry" Slow -> "slow" RednCounts -> "ct" ConEntry -> "con_entry" ConInfoTable -> "con_info" ClosureTable -> "closure_tbl" Bytes -> "bytes" BlockInfoTable -> "info" ) pp_cSEP :: SDoc pp_cSEP = char '_' instance Outputable ForeignLabelSource where ppr fs = case fs of ForeignLabelInPackage pkgId -> parens $ text "package: " <> ppr pkgId ForeignLabelInThisPackage -> parens $ text "this package" ForeignLabelInExternalPackage -> parens $ text "external package" internalNamePrefix :: Name -> SDoc internalNamePrefix name = getPprStyle $ \ sty -> if asmStyle sty && isRandomGenerated then sdocWithPlatform $ \platform -> ptext (asmTempLabelPrefix platform) else empty where isRandomGenerated = not $ isExternalName name tempLabelPrefixOrUnderscore :: SDoc tempLabelPrefixOrUnderscore = sdocWithPlatform $ \platform -> getPprStyle $ \ sty -> if asmStyle sty then ptext (asmTempLabelPrefix platform) else char '_' -- ----------------------------------------------------------------------------- -- Machine-dependent knowledge about labels. asmTempLabelPrefix :: Platform -> PtrString -- for formatting labels asmTempLabelPrefix platform = case platformOS platform of OSDarwin -> sLit "L" OSAIX -> sLit "__L" -- follow IBM XL C's convention _ -> sLit ".L" pprDynamicLinkerAsmLabel :: Platform -> DynamicLinkerLabelInfo -> CLabel -> SDoc pprDynamicLinkerAsmLabel platform dllInfo lbl = case platformOS platform of OSDarwin | platformArch platform == ArchX86_64 -> case dllInfo of CodeStub -> char 'L' <> ppr lbl <> text "$stub" SymbolPtr -> char 'L' <> ppr lbl <> text "$non_lazy_ptr" GotSymbolPtr -> ppr lbl <> text "@GOTPCREL" GotSymbolOffset -> ppr lbl | otherwise -> case dllInfo of CodeStub -> char 'L' <> ppr lbl <> text "$stub" SymbolPtr -> char 'L' <> ppr lbl <> text "$non_lazy_ptr" _ -> panic "pprDynamicLinkerAsmLabel" OSAIX -> case dllInfo of SymbolPtr -> text "LC.." <> ppr lbl -- GCC's naming convention _ -> panic "pprDynamicLinkerAsmLabel" _ | osElfTarget (platformOS platform) -> elfLabel OSMinGW32 -> case dllInfo of SymbolPtr -> text "__imp_" <> ppr lbl _ -> panic "pprDynamicLinkerAsmLabel" _ -> panic "pprDynamicLinkerAsmLabel" where elfLabel | platformArch platform == ArchPPC = case dllInfo of CodeStub -> -- See Note [.LCTOC1 in PPC PIC code] ppr lbl <> text "+32768@plt" SymbolPtr -> text ".LC_" <> ppr lbl _ -> panic "pprDynamicLinkerAsmLabel" | platformArch platform == ArchX86_64 = case dllInfo of CodeStub -> ppr lbl <> text "@plt" GotSymbolPtr -> ppr lbl <> text "@gotpcrel" GotSymbolOffset -> ppr lbl SymbolPtr -> text ".LC_" <> ppr lbl | platformArch platform == ArchPPC_64 ELF_V1 || platformArch platform == ArchPPC_64 ELF_V2 = case dllInfo of GotSymbolPtr -> text ".LC_" <> ppr lbl <> text "@toc" GotSymbolOffset -> ppr lbl SymbolPtr -> text ".LC_" <> ppr lbl _ -> panic "pprDynamicLinkerAsmLabel" | otherwise = case dllInfo of CodeStub -> ppr lbl <> text "@plt" SymbolPtr -> text ".LC_" <> ppr lbl GotSymbolPtr -> ppr lbl <> text "@got" GotSymbolOffset -> ppr lbl <> text "@gotoff" -- Figure out whether `symbol` may serve as an alias -- to `target` within one compilation unit. -- -- This is true if any of these holds: -- * `target` is a module-internal haskell name. -- * `target` is an exported name, but comes from the same -- module as `symbol` -- -- These are sufficient conditions for establishing e.g. a -- GNU assembly alias ('.equiv' directive). Sadly, there is -- no such thing as an alias to an imported symbol (conf. -- http://blog.omega-prime.co.uk/2011/07/06/the-sad-state-of-symbol-aliases/) -- See note [emit-time elimination of static indirections]. -- -- Precondition is that both labels represent the -- same semantic value. mayRedirectTo :: CLabel -> CLabel -> Bool mayRedirectTo symbol target | Just nam <- haskellName , staticClosureLabel , isExternalName nam , Just mod <- nameModule_maybe nam , Just anam <- hasHaskellName symbol , Just amod <- nameModule_maybe anam = amod == mod | Just nam <- haskellName , staticClosureLabel , isInternalName nam = True | otherwise = False where staticClosureLabel = isStaticClosureLabel target haskellName = hasHaskellName target {- Note [emit-time elimination of static indirections] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ As described in #15155, certain static values are repesentationally equivalent, e.g. 'cast'ed values (when created by 'newtype' wrappers). newtype A = A Int {-# NOINLINE a #-} a = A 42 a1_rYB :: Int [GblId, Caf=NoCafRefs, Unf=OtherCon []] a1_rYB = GHC.Types.I# 42# a [InlPrag=NOINLINE] :: A [GblId, Unf=OtherCon []] a = a1_rYB `cast` (Sym (T15155.N:A[0]) :: Int ~R# A) Formerly we created static indirections for these (IND_STATIC), which consist of a statically allocated forwarding closure that contains the (possibly tagged) indirectee. (See CMM/assembly below.) This approach is suboptimal for two reasons: (a) they occupy extra space, (b) they need to be entered in order to obtain the indirectee, thus they cannot be tagged. Fortunately there is a common case where static indirections can be eliminated while emitting assembly (native or LLVM), viz. when the indirectee is in the same module (object file) as the symbol that points to it. In this case an assembly-level identification can be created ('.equiv' directive), and as such the same object will be assigned two names in the symbol table. Any of the identified symbols can be referenced by a tagged pointer. Currently the 'mayRedirectTo' predicate will give a clue whether a label can be equated with another, already emitted, label (which can in turn be an alias). The general mechanics is that we identify data (IND_STATIC closures) that are amenable to aliasing while pretty-printing of assembly output, and emit the '.equiv' directive instead of static data in such a case. Here is a sketch how the output is massaged: Consider newtype A = A Int {-# NOINLINE a #-} a = A 42 -- I# 42# is the indirectee -- 'a' is exported results in STG a1_rXq :: GHC.Types.Int [GblId, Caf=NoCafRefs, Unf=OtherCon []] = CCS_DONT_CARE GHC.Types.I#! [42#]; T15155.a [InlPrag=NOINLINE] :: T15155.A [GblId, Unf=OtherCon []] = CAF_ccs \ u [] a1_rXq; and CMM [section ""data" . a1_rXq_closure" { a1_rXq_closure: const GHC.Types.I#_con_info; const 42; }] [section ""data" . T15155.a_closure" { T15155.a_closure: const stg_IND_STATIC_info; const a1_rXq_closure+1; const 0; const 0; }] The emitted assembly is #### INDIRECTEE a1_rXq_closure: -- module local haskell value .quad GHC.Types.I#_con_info -- an Int .quad 42 #### BEFORE .globl T15155.a_closure -- exported newtype wrapped value T15155.a_closure: .quad stg_IND_STATIC_info -- the closure info .quad a1_rXq_closure+1 -- indirectee ('+1' being the tag) .quad 0 .quad 0 #### AFTER .globl T15155.a_closure -- exported newtype wrapped value .equiv a1_rXq_closure,T15155.a_closure -- both are shared The transformation is performed because T15155.a_closure `mayRedirectTo` a1_rXq_closure+1 returns True. -}