{-# LANGUAGE CPP, RecordWildCards #-}

-----------------------------------------------------------------------------
--
-- Stg to C-- code generation:
--
-- The types   LambdaFormInfo
--             ClosureInfo
--
-- Nothing monadic in here!
--
-----------------------------------------------------------------------------

module GHC.StgToCmm.Closure (
        DynTag,  tagForCon, isSmallFamily,

        idPrimRep, isVoidRep, isGcPtrRep, addIdReps, addArgReps,
        argPrimRep,

        NonVoid(..), fromNonVoid, nonVoidIds, nonVoidStgArgs,
        assertNonVoidIds, assertNonVoidStgArgs,

        -- * LambdaFormInfo
        LambdaFormInfo,         -- Abstract
        StandardFormInfo,        -- ...ditto...
        mkLFThunk, mkLFReEntrant, mkConLFInfo, mkSelectorLFInfo,
        mkApLFInfo, mkLFImported, mkLFArgument, mkLFLetNoEscape,
        mkLFStringLit,
        lfDynTag,
        isLFThunk, isLFReEntrant, lfUpdatable,

        -- * Used by other modules
        CgLoc(..), SelfLoopInfo, CallMethod(..),
        nodeMustPointToIt, isKnownFun, funTag, tagForArity, getCallMethod,

        -- * ClosureInfo
        ClosureInfo,
        mkClosureInfo,
        mkCmmInfo,

        -- ** Inspection
        closureLFInfo, closureName,

        -- ** Labels
        -- These just need the info table label
        closureInfoLabel, staticClosureLabel,
        closureSlowEntryLabel, closureLocalEntryLabel,

        -- ** Predicates
        -- These are really just functions on LambdaFormInfo
        closureUpdReqd, closureSingleEntry,
        closureReEntrant, closureFunInfo,
        isToplevClosure,

        blackHoleOnEntry,  -- Needs LambdaFormInfo and SMRep
        isStaticClosure,   -- Needs SMPre

        -- * InfoTables
        mkDataConInfoTable,
        cafBlackHoleInfoTable,
        indStaticInfoTable,
        staticClosureNeedsLink,
    ) where

#include "HsVersions.h"

import GhcPrelude

import StgSyn
import SMRep
import Cmm
import PprCmmExpr() -- For Outputable instances

import CostCentre
import BlockId
import CLabel
import Id
import IdInfo
import DataCon
import Name
import Type
import TyCoRep
import TcType
import TyCon
import RepType
import BasicTypes
import Outputable
import DynFlags
import Util

import Data.Coerce (coerce)
import qualified Data.ByteString.Char8 as BS8

-----------------------------------------------------------------------------
--                Data types and synonyms
-----------------------------------------------------------------------------

-- These data types are mostly used by other modules, especially
-- GHC.StgToCmm.Monad, but we define them here because some functions in this
-- module need to have access to them as well

data CgLoc
  = CmmLoc CmmExpr      -- A stable CmmExpr; that is, one not mentioning
                        -- Hp, so that it remains valid across calls

  | LneLoc BlockId [LocalReg]             -- A join point
        -- A join point (= let-no-escape) should only
        -- be tail-called, and in a saturated way.
        -- To tail-call it, assign to these locals,
        -- and branch to the block id

instance Outputable CgLoc where
  ppr :: CgLoc -> SDoc
ppr (CmmLoc CmmExpr
e)    = String -> SDoc
text String
"cmm" SDoc -> SDoc -> SDoc
<+> CmmExpr -> SDoc
forall a. Outputable a => a -> SDoc
ppr CmmExpr
e
  ppr (LneLoc BlockId
b [LocalReg]
rs) = String -> SDoc
text String
"lne" SDoc -> SDoc -> SDoc
<+> BlockId -> SDoc
forall a. Outputable a => a -> SDoc
ppr BlockId
b SDoc -> SDoc -> SDoc
<+> [LocalReg] -> SDoc
forall a. Outputable a => a -> SDoc
ppr [LocalReg]
rs

type SelfLoopInfo = (Id, BlockId, [LocalReg])

-- used by ticky profiling
isKnownFun :: LambdaFormInfo -> Bool
isKnownFun :: LambdaFormInfo -> Bool
isKnownFun LFReEntrant{} = Bool
True
isKnownFun LambdaFormInfo
LFLetNoEscape = Bool
True
isKnownFun LambdaFormInfo
_             = Bool
False


-------------------------------------
--        Non-void types
-------------------------------------
-- We frequently need the invariant that an Id or a an argument
-- is of a non-void type. This type is a witness to the invariant.

newtype NonVoid a = NonVoid a
  deriving (NonVoid a -> NonVoid a -> Bool
(NonVoid a -> NonVoid a -> Bool)
-> (NonVoid a -> NonVoid a -> Bool) -> Eq (NonVoid a)
forall a. Eq a => NonVoid a -> NonVoid a -> Bool
forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
/= :: NonVoid a -> NonVoid a -> Bool
$c/= :: forall a. Eq a => NonVoid a -> NonVoid a -> Bool
== :: NonVoid a -> NonVoid a -> Bool
$c== :: forall a. Eq a => NonVoid a -> NonVoid a -> Bool
Eq, Int -> NonVoid a -> ShowS
[NonVoid a] -> ShowS
NonVoid a -> String
(Int -> NonVoid a -> ShowS)
-> (NonVoid a -> String)
-> ([NonVoid a] -> ShowS)
-> Show (NonVoid a)
forall a. Show a => Int -> NonVoid a -> ShowS
forall a. Show a => [NonVoid a] -> ShowS
forall a. Show a => NonVoid a -> String
forall a.
(Int -> a -> ShowS) -> (a -> String) -> ([a] -> ShowS) -> Show a
showList :: [NonVoid a] -> ShowS
$cshowList :: forall a. Show a => [NonVoid a] -> ShowS
show :: NonVoid a -> String
$cshow :: forall a. Show a => NonVoid a -> String
showsPrec :: Int -> NonVoid a -> ShowS
$cshowsPrec :: forall a. Show a => Int -> NonVoid a -> ShowS
Show)

fromNonVoid :: NonVoid a -> a
fromNonVoid :: NonVoid a -> a
fromNonVoid (NonVoid a
a) = a
a

instance (Outputable a) => Outputable (NonVoid a) where
  ppr :: NonVoid a -> SDoc
ppr (NonVoid a
a) = a -> SDoc
forall a. Outputable a => a -> SDoc
ppr a
a

nonVoidIds :: [Id] -> [NonVoid Id]
nonVoidIds :: [Id] -> [NonVoid Id]
nonVoidIds [Id]
ids = [Id -> NonVoid Id
forall a. a -> NonVoid a
NonVoid Id
id | Id
id <- [Id]
ids, Bool -> Bool
not (Type -> Bool
isVoidTy (Id -> Type
idType Id
id))]

-- | Used in places where some invariant ensures that all these Ids are
-- non-void; e.g. constructor field binders in case expressions.
-- See Note [Post-unarisation invariants] in UnariseStg.
assertNonVoidIds :: [Id] -> [NonVoid Id]
assertNonVoidIds :: [Id] -> [NonVoid Id]
assertNonVoidIds [Id]
ids = ASSERT(not (any (isVoidTy . idType) ids))
                       [Id] -> [NonVoid Id]
coerce [Id]
ids

nonVoidStgArgs :: [StgArg] -> [NonVoid StgArg]
nonVoidStgArgs :: [StgArg] -> [NonVoid StgArg]
nonVoidStgArgs [StgArg]
args = [StgArg -> NonVoid StgArg
forall a. a -> NonVoid a
NonVoid StgArg
arg | StgArg
arg <- [StgArg]
args, Bool -> Bool
not (Type -> Bool
isVoidTy (StgArg -> Type
stgArgType StgArg
arg))]

-- | Used in places where some invariant ensures that all these arguments are
-- non-void; e.g. constructor arguments.
-- See Note [Post-unarisation invariants] in UnariseStg.
assertNonVoidStgArgs :: [StgArg] -> [NonVoid StgArg]
assertNonVoidStgArgs :: [StgArg] -> [NonVoid StgArg]
assertNonVoidStgArgs [StgArg]
args = ASSERT(not (any (isVoidTy . stgArgType) args))
                            [StgArg] -> [NonVoid StgArg]
coerce [StgArg]
args


-----------------------------------------------------------------------------
--                Representations
-----------------------------------------------------------------------------

-- Why are these here?

-- | Assumes that there is precisely one 'PrimRep' of the type. This assumption
-- holds after unarise.
-- See Note [Post-unarisation invariants]
idPrimRep :: Id -> PrimRep
idPrimRep :: Id -> PrimRep
idPrimRep Id
id = HasDebugCallStack => Type -> PrimRep
Type -> PrimRep
typePrimRep1 (Id -> Type
idType Id
id)
    -- See also Note [VoidRep] in RepType

-- | Assumes that Ids have one PrimRep, which holds after unarisation.
-- See Note [Post-unarisation invariants]
addIdReps :: [NonVoid Id] -> [NonVoid (PrimRep, Id)]
addIdReps :: [NonVoid Id] -> [NonVoid (PrimRep, Id)]
addIdReps = (NonVoid Id -> NonVoid (PrimRep, Id))
-> [NonVoid Id] -> [NonVoid (PrimRep, Id)]
forall a b. (a -> b) -> [a] -> [b]
map (\NonVoid Id
id -> let id' :: Id
id' = NonVoid Id -> Id
forall a. NonVoid a -> a
fromNonVoid NonVoid Id
id
                         in (PrimRep, Id) -> NonVoid (PrimRep, Id)
forall a. a -> NonVoid a
NonVoid (Id -> PrimRep
idPrimRep Id
id', Id
id'))

-- | Assumes that arguments have one PrimRep, which holds after unarisation.
-- See Note [Post-unarisation invariants]
addArgReps :: [NonVoid StgArg] -> [NonVoid (PrimRep, StgArg)]
addArgReps :: [NonVoid StgArg] -> [NonVoid (PrimRep, StgArg)]
addArgReps = (NonVoid StgArg -> NonVoid (PrimRep, StgArg))
-> [NonVoid StgArg] -> [NonVoid (PrimRep, StgArg)]
forall a b. (a -> b) -> [a] -> [b]
map (\NonVoid StgArg
arg -> let arg' :: StgArg
arg' = NonVoid StgArg -> StgArg
forall a. NonVoid a -> a
fromNonVoid NonVoid StgArg
arg
                           in (PrimRep, StgArg) -> NonVoid (PrimRep, StgArg)
forall a. a -> NonVoid a
NonVoid (StgArg -> PrimRep
argPrimRep StgArg
arg', StgArg
arg'))

-- | Assumes that the argument has one PrimRep, which holds after unarisation.
-- See Note [Post-unarisation invariants]
argPrimRep :: StgArg -> PrimRep
argPrimRep :: StgArg -> PrimRep
argPrimRep StgArg
arg = HasDebugCallStack => Type -> PrimRep
Type -> PrimRep
typePrimRep1 (StgArg -> Type
stgArgType StgArg
arg)


-----------------------------------------------------------------------------
--                LambdaFormInfo
-----------------------------------------------------------------------------

-- Information about an identifier, from the code generator's point of
-- view.  Every identifier is bound to a LambdaFormInfo in the
-- environment, which gives the code generator enough info to be able to
-- tail call or return that identifier.

data LambdaFormInfo
  = LFReEntrant         -- Reentrant closure (a function)
        TopLevelFlag    -- True if top level
        OneShotInfo
        !RepArity       -- Arity. Invariant: always > 0
        !Bool           -- True <=> no fvs
        ArgDescr        -- Argument descriptor (should really be in ClosureInfo)

  | LFThunk             -- Thunk (zero arity)
        TopLevelFlag
        !Bool           -- True <=> no free vars
        !Bool           -- True <=> updatable (i.e., *not* single-entry)
        StandardFormInfo
        !Bool           -- True <=> *might* be a function type

  | LFCon               -- A saturated constructor application
        DataCon         -- The constructor

  | LFUnknown           -- Used for function arguments and imported things.
                        -- We know nothing about this closure.
                        -- Treat like updatable "LFThunk"...
                        -- Imported things which we *do* know something about use
                        -- one of the other LF constructors (eg LFReEntrant for
                        -- known functions)
        !Bool           -- True <=> *might* be a function type
                        --      The False case is good when we want to enter it,
                        --        because then we know the entry code will do
                        --        For a function, the entry code is the fast entry point

  | LFUnlifted          -- A value of unboxed type;
                        -- always a value, needs evaluation

  | LFLetNoEscape       -- See LetNoEscape module for precise description


-------------------------
-- StandardFormInfo tells whether this thunk has one of
-- a small number of standard forms

data StandardFormInfo
  = NonStandardThunk
        -- The usual case: not of the standard forms

  | SelectorThunk
        -- A SelectorThunk is of form
        --      case x of
        --           con a1,..,an -> ak
        -- and the constructor is from a single-constr type.
       WordOff          -- 0-origin offset of ak within the "goods" of
                        -- constructor (Recall that the a1,...,an may be laid
                        -- out in the heap in a non-obvious order.)

  | ApThunk
        -- An ApThunk is of form
        --        x1 ... xn
        -- The code for the thunk just pushes x2..xn on the stack and enters x1.
        -- There are a few of these (for 1 <= n <= MAX_SPEC_AP_SIZE) pre-compiled
        -- in the RTS to save space.
        RepArity                -- Arity, n


------------------------------------------------------
--                Building LambdaFormInfo
------------------------------------------------------

mkLFArgument :: Id -> LambdaFormInfo
mkLFArgument :: Id -> LambdaFormInfo
mkLFArgument Id
id
  | HasDebugCallStack => Type -> Bool
Type -> Bool
isUnliftedType Type
ty      = LambdaFormInfo
LFUnlifted
  | Type -> Bool
might_be_a_function Type
ty = Bool -> LambdaFormInfo
LFUnknown Bool
True
  | Bool
otherwise              = Bool -> LambdaFormInfo
LFUnknown Bool
False
  where
    ty :: Type
ty = Id -> Type
idType Id
id

-------------
mkLFLetNoEscape :: LambdaFormInfo
mkLFLetNoEscape :: LambdaFormInfo
mkLFLetNoEscape = LambdaFormInfo
LFLetNoEscape

-------------
mkLFReEntrant :: TopLevelFlag    -- True of top level
              -> [Id]            -- Free vars
              -> [Id]            -- Args
              -> ArgDescr        -- Argument descriptor
              -> LambdaFormInfo

mkLFReEntrant :: TopLevelFlag -> [Id] -> [Id] -> ArgDescr -> LambdaFormInfo
mkLFReEntrant TopLevelFlag
_ [Id]
_ [] ArgDescr
_
  = String -> SDoc -> LambdaFormInfo
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"mkLFReEntrant" SDoc
empty
mkLFReEntrant TopLevelFlag
top [Id]
fvs [Id]
args ArgDescr
arg_descr
  = TopLevelFlag
-> OneShotInfo -> Int -> Bool -> ArgDescr -> LambdaFormInfo
LFReEntrant TopLevelFlag
top OneShotInfo
os_info ([Id] -> Int
forall (t :: * -> *) a. Foldable t => t a -> Int
length [Id]
args) ([Id] -> Bool
forall (t :: * -> *) a. Foldable t => t a -> Bool
null [Id]
fvs) ArgDescr
arg_descr
  where os_info :: OneShotInfo
os_info = Id -> OneShotInfo
idOneShotInfo ([Id] -> Id
forall a. [a] -> a
head [Id]
args)

-------------
mkLFThunk :: Type -> TopLevelFlag -> [Id] -> UpdateFlag -> LambdaFormInfo
mkLFThunk :: Type -> TopLevelFlag -> [Id] -> UpdateFlag -> LambdaFormInfo
mkLFThunk Type
thunk_ty TopLevelFlag
top [Id]
fvs UpdateFlag
upd_flag
  = ASSERT( not (isUpdatable upd_flag) || not (isUnliftedType thunk_ty) )
    TopLevelFlag
-> Bool -> Bool -> StandardFormInfo -> Bool -> LambdaFormInfo
LFThunk TopLevelFlag
top ([Id] -> Bool
forall (t :: * -> *) a. Foldable t => t a -> Bool
null [Id]
fvs)
            (UpdateFlag -> Bool
isUpdatable UpdateFlag
upd_flag)
            StandardFormInfo
NonStandardThunk
            (Type -> Bool
might_be_a_function Type
thunk_ty)

--------------
might_be_a_function :: Type -> Bool
-- Return False only if we are *sure* it's a data type
-- Look through newtypes etc as much as poss
might_be_a_function :: Type -> Bool
might_be_a_function Type
ty
  | [PrimRep
LiftedRep] <- HasDebugCallStack => Type -> [PrimRep]
Type -> [PrimRep]
typePrimRep Type
ty
  , Just TyCon
tc <- Type -> Maybe TyCon
tyConAppTyCon_maybe (Type -> Type
unwrapType Type
ty)
  , TyCon -> Bool
isDataTyCon TyCon
tc
  = Bool
False
  | Bool
otherwise
  = Bool
True

-------------
mkConLFInfo :: DataCon -> LambdaFormInfo
mkConLFInfo :: DataCon -> LambdaFormInfo
mkConLFInfo DataCon
con = DataCon -> LambdaFormInfo
LFCon DataCon
con

-------------
mkSelectorLFInfo :: Id -> Int -> Bool -> LambdaFormInfo
mkSelectorLFInfo :: Id -> Int -> Bool -> LambdaFormInfo
mkSelectorLFInfo Id
id Int
offset Bool
updatable
  = TopLevelFlag
-> Bool -> Bool -> StandardFormInfo -> Bool -> LambdaFormInfo
LFThunk TopLevelFlag
NotTopLevel Bool
False Bool
updatable (Int -> StandardFormInfo
SelectorThunk Int
offset)
        (Type -> Bool
might_be_a_function (Id -> Type
idType Id
id))

-------------
mkApLFInfo :: Id -> UpdateFlag -> Arity -> LambdaFormInfo
mkApLFInfo :: Id -> UpdateFlag -> Int -> LambdaFormInfo
mkApLFInfo Id
id UpdateFlag
upd_flag Int
arity
  = TopLevelFlag
-> Bool -> Bool -> StandardFormInfo -> Bool -> LambdaFormInfo
LFThunk TopLevelFlag
NotTopLevel (Int
arity Int -> Int -> Bool
forall a. Eq a => a -> a -> Bool
== Int
0) (UpdateFlag -> Bool
isUpdatable UpdateFlag
upd_flag) (Int -> StandardFormInfo
ApThunk Int
arity)
        (Type -> Bool
might_be_a_function (Id -> Type
idType Id
id))

-------------
mkLFImported :: Id -> LambdaFormInfo
mkLFImported :: Id -> LambdaFormInfo
mkLFImported Id
id
  | Just DataCon
con <- Id -> Maybe DataCon
isDataConWorkId_maybe Id
id
  , DataCon -> Bool
isNullaryRepDataCon DataCon
con
  = DataCon -> LambdaFormInfo
LFCon DataCon
con   -- An imported nullary constructor
                -- We assume that the constructor is evaluated so that
                -- the id really does point directly to the constructor

  | Int
arity Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
> Int
0
  = TopLevelFlag
-> OneShotInfo -> Int -> Bool -> ArgDescr -> LambdaFormInfo
LFReEntrant TopLevelFlag
TopLevel OneShotInfo
noOneShotInfo Int
arity Bool
True (String -> ArgDescr
forall a. String -> a
panic String
"arg_descr")

  | Bool
otherwise
  = Id -> LambdaFormInfo
mkLFArgument Id
id -- Not sure of exact arity
  where
    arity :: Int
arity = Id -> Int
idFunRepArity Id
id

-------------
mkLFStringLit :: LambdaFormInfo
mkLFStringLit :: LambdaFormInfo
mkLFStringLit = LambdaFormInfo
LFUnlifted

-----------------------------------------------------
--                Dynamic pointer tagging
-----------------------------------------------------

type DynTag = Int       -- The tag on a *pointer*
                        -- (from the dynamic-tagging paper)

-- Note [Data constructor dynamic tags]
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
-- The family size of a data type (the number of constructors
-- or the arity of a function) can be either:
--    * small, if the family size < 2**tag_bits
--    * big, otherwise.
--
-- Small families can have the constructor tag in the tag bits.
-- Big families always use the tag values 1..mAX_PTR_TAG to represent
-- evaluatedness, the last one lumping together all overflowing ones.
-- We don't have very many tag bits: for example, we have 2 bits on
-- x86-32 and 3 bits on x86-64.
--
-- Also see Note [Tagging big families] in GHC.StgToCmm.Expr

isSmallFamily :: DynFlags -> Int -> Bool
isSmallFamily :: DynFlags -> Int -> Bool
isSmallFamily DynFlags
dflags Int
fam_size = Int
fam_size Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
<= DynFlags -> Int
mAX_PTR_TAG DynFlags
dflags

tagForCon :: DynFlags -> DataCon -> DynTag
tagForCon :: DynFlags -> DataCon -> Int
tagForCon DynFlags
dflags DataCon
con = Int -> Int -> Int
forall a. Ord a => a -> a -> a
min (DataCon -> Int
dataConTag DataCon
con) (DynFlags -> Int
mAX_PTR_TAG DynFlags
dflags)
-- NB: 1-indexed

tagForArity :: DynFlags -> RepArity -> DynTag
tagForArity :: DynFlags -> Int -> Int
tagForArity DynFlags
dflags Int
arity
 | DynFlags -> Int -> Bool
isSmallFamily DynFlags
dflags Int
arity = Int
arity
 | Bool
otherwise                  = Int
0

lfDynTag :: DynFlags -> LambdaFormInfo -> DynTag
-- Return the tag in the low order bits of a variable bound
-- to this LambdaForm
lfDynTag :: DynFlags -> LambdaFormInfo -> Int
lfDynTag DynFlags
dflags (LFCon DataCon
con)                 = DynFlags -> DataCon -> Int
tagForCon DynFlags
dflags DataCon
con
lfDynTag DynFlags
dflags (LFReEntrant TopLevelFlag
_ OneShotInfo
_ Int
arity Bool
_ ArgDescr
_) = DynFlags -> Int -> Int
tagForArity DynFlags
dflags Int
arity
lfDynTag DynFlags
_      LambdaFormInfo
_other                      = Int
0


-----------------------------------------------------------------------------
--                Observing LambdaFormInfo
-----------------------------------------------------------------------------

------------
isLFThunk :: LambdaFormInfo -> Bool
isLFThunk :: LambdaFormInfo -> Bool
isLFThunk (LFThunk {})  = Bool
True
isLFThunk LambdaFormInfo
_ = Bool
False

isLFReEntrant :: LambdaFormInfo -> Bool
isLFReEntrant :: LambdaFormInfo -> Bool
isLFReEntrant (LFReEntrant {}) = Bool
True
isLFReEntrant LambdaFormInfo
_                = Bool
False

-----------------------------------------------------------------------------
--                Choosing SM reps
-----------------------------------------------------------------------------

lfClosureType :: LambdaFormInfo -> ClosureTypeInfo
lfClosureType :: LambdaFormInfo -> ClosureTypeInfo
lfClosureType (LFReEntrant TopLevelFlag
_ OneShotInfo
_ Int
arity Bool
_ ArgDescr
argd) = Int -> ArgDescr -> ClosureTypeInfo
Fun Int
arity ArgDescr
argd
lfClosureType (LFCon DataCon
con)                    = Int -> ConstrDescription -> ClosureTypeInfo
Constr (DataCon -> Int
dataConTagZ DataCon
con)
                                                      (DataCon -> ConstrDescription
dataConIdentity DataCon
con)
lfClosureType (LFThunk TopLevelFlag
_ Bool
_ Bool
_ StandardFormInfo
is_sel Bool
_)       = StandardFormInfo -> ClosureTypeInfo
thunkClosureType StandardFormInfo
is_sel
lfClosureType LambdaFormInfo
_                              = String -> ClosureTypeInfo
forall a. String -> a
panic String
"lfClosureType"

thunkClosureType :: StandardFormInfo -> ClosureTypeInfo
thunkClosureType :: StandardFormInfo -> ClosureTypeInfo
thunkClosureType (SelectorThunk Int
off) = Int -> ClosureTypeInfo
ThunkSelector Int
off
thunkClosureType StandardFormInfo
_                   = ClosureTypeInfo
Thunk

-- We *do* get non-updatable top-level thunks sometimes.  eg. f = g
-- gets compiled to a jump to g (if g has non-zero arity), instead of
-- messing around with update frames and PAPs.  We set the closure type
-- to FUN_STATIC in this case.

-----------------------------------------------------------------------------
--                nodeMustPointToIt
-----------------------------------------------------------------------------

nodeMustPointToIt :: DynFlags -> LambdaFormInfo -> Bool
-- If nodeMustPointToIt is true, then the entry convention for
-- this closure has R1 (the "Node" register) pointing to the
-- closure itself --- the "self" argument

nodeMustPointToIt :: DynFlags -> LambdaFormInfo -> Bool
nodeMustPointToIt DynFlags
_ (LFReEntrant TopLevelFlag
top OneShotInfo
_ Int
_ Bool
no_fvs ArgDescr
_)
  =  Bool -> Bool
not Bool
no_fvs          -- Certainly if it has fvs we need to point to it
  Bool -> Bool -> Bool
|| TopLevelFlag -> Bool
isNotTopLevel TopLevelFlag
top   -- See Note [GC recovery]
        -- For lex_profiling we also access the cost centre for a
        -- non-inherited (i.e. non-top-level) function.
        -- The isNotTopLevel test above ensures this is ok.

nodeMustPointToIt DynFlags
dflags (LFThunk TopLevelFlag
top Bool
no_fvs Bool
updatable StandardFormInfo
NonStandardThunk Bool
_)
  =  Bool -> Bool
not Bool
no_fvs            -- Self parameter
  Bool -> Bool -> Bool
|| TopLevelFlag -> Bool
isNotTopLevel TopLevelFlag
top     -- Note [GC recovery]
  Bool -> Bool -> Bool
|| Bool
updatable             -- Need to push update frame
  Bool -> Bool -> Bool
|| GeneralFlag -> DynFlags -> Bool
gopt GeneralFlag
Opt_SccProfilingOn DynFlags
dflags
          -- For the non-updatable (single-entry case):
          --
          -- True if has fvs (in which case we need access to them, and we
          --                    should black-hole it)
          -- or profiling (in which case we need to recover the cost centre
          --                 from inside it)  ToDo: do we need this even for
          --                                    top-level thunks? If not,
          --                                    isNotTopLevel subsumes this

nodeMustPointToIt DynFlags
_ (LFThunk {})        -- Node must point to a standard-form thunk
  = Bool
True

nodeMustPointToIt DynFlags
_ (LFCon DataCon
_) = Bool
True

        -- Strictly speaking, the above two don't need Node to point
        -- to it if the arity = 0.  But this is a *really* unlikely
        -- situation.  If we know it's nil (say) and we are entering
        -- it. Eg: let x = [] in x then we will certainly have inlined
        -- x, since nil is a simple atom.  So we gain little by not
        -- having Node point to known zero-arity things.  On the other
        -- hand, we do lose something; Patrick's code for figuring out
        -- when something has been updated but not entered relies on
        -- having Node point to the result of an update.  SLPJ
        -- 27/11/92.

nodeMustPointToIt DynFlags
_ (LFUnknown Bool
_)   = Bool
True
nodeMustPointToIt DynFlags
_ LambdaFormInfo
LFUnlifted      = Bool
False
nodeMustPointToIt DynFlags
_ LambdaFormInfo
LFLetNoEscape   = Bool
False

{- Note [GC recovery]
~~~~~~~~~~~~~~~~~~~~~
If we a have a local let-binding (function or thunk)
   let f = <body> in ...
AND <body> allocates, then the heap-overflow check needs to know how
to re-start the evaluation.  It uses the "self" pointer to do this.
So even if there are no free variables in <body>, we still make
nodeMustPointToIt be True for non-top-level bindings.

Why do any such bindings exist?  After all, let-floating should have
floated them out.  Well, a clever optimiser might leave one there to
avoid a space leak, deliberately recomputing a thunk.  Also (and this
really does happen occasionally) let-floating may make a function f smaller
so it can be inlined, so now (f True) may generate a local no-fv closure.
This actually happened during bootstrapping GHC itself, with f=mkRdrFunBind
in TcGenDeriv.) -}

-----------------------------------------------------------------------------
--                getCallMethod
-----------------------------------------------------------------------------

{- The entry conventions depend on the type of closure being entered,
whether or not it has free variables, and whether we're running
sequentially or in parallel.

Closure                           Node   Argument   Enter
Characteristics              Par   Req'd  Passing    Via
---------------------------------------------------------------------------
Unknown                     & no  & yes & stack     & node
Known fun (>1 arg), no fvs  & no  & no  & registers & fast entry (enough args)
                                                    & slow entry (otherwise)
Known fun (>1 arg), fvs     & no  & yes & registers & fast entry (enough args)
0 arg, no fvs \r,\s         & no  & no  & n/a       & direct entry
0 arg, no fvs \u            & no  & yes & n/a       & node
0 arg, fvs \r,\s,selector   & no  & yes & n/a       & node
0 arg, fvs \r,\s            & no  & yes & n/a       & direct entry
0 arg, fvs \u               & no  & yes & n/a       & node
Unknown                     & yes & yes & stack     & node
Known fun (>1 arg), no fvs  & yes & no  & registers & fast entry (enough args)
                                                    & slow entry (otherwise)
Known fun (>1 arg), fvs     & yes & yes & registers & node
0 arg, fvs \r,\s,selector   & yes & yes & n/a       & node
0 arg, no fvs \r,\s         & yes & no  & n/a       & direct entry
0 arg, no fvs \u            & yes & yes & n/a       & node
0 arg, fvs \r,\s            & yes & yes & n/a       & node
0 arg, fvs \u               & yes & yes & n/a       & node

When black-holing, single-entry closures could also be entered via node
(rather than directly) to catch double-entry. -}

data CallMethod
  = EnterIt             -- No args, not a function

  | JumpToIt BlockId [LocalReg] -- A join point or a header of a local loop

  | ReturnIt            -- It's a value (function, unboxed value,
                        -- or constructor), so just return it.

  | SlowCall                -- Unknown fun, or known fun with
                        -- too few args.

  | DirectEntry         -- Jump directly, with args in regs
        CLabel          --   The code label
        RepArity        --   Its arity

getCallMethod :: DynFlags
              -> Name           -- Function being applied
              -> Id             -- Function Id used to chech if it can refer to
                                -- CAF's and whether the function is tail-calling
                                -- itself
              -> LambdaFormInfo -- Its info
              -> RepArity       -- Number of available arguments
              -> RepArity       -- Number of them being void arguments
              -> CgLoc          -- Passed in from cgIdApp so that we can
                                -- handle let-no-escape bindings and self-recursive
                                -- tail calls using the same data constructor,
                                -- JumpToIt. This saves us one case branch in
                                -- cgIdApp
              -> Maybe SelfLoopInfo -- can we perform a self-recursive tail call?
              -> CallMethod

getCallMethod :: DynFlags
-> Name
-> Id
-> LambdaFormInfo
-> Int
-> Int
-> CgLoc
-> Maybe SelfLoopInfo
-> CallMethod
getCallMethod DynFlags
dflags Name
_ Id
id LambdaFormInfo
_ Int
n_args Int
v_args CgLoc
_cg_loc
              (Just (Id
self_loop_id, BlockId
block_id, [LocalReg]
args))
  | GeneralFlag -> DynFlags -> Bool
gopt GeneralFlag
Opt_Loopification DynFlags
dflags
  , Id
id Id -> Id -> Bool
forall a. Eq a => a -> a -> Bool
== Id
self_loop_id
  , [LocalReg]
args [LocalReg] -> Int -> Bool
forall a. [a] -> Int -> Bool
`lengthIs` (Int
n_args Int -> Int -> Int
forall a. Num a => a -> a -> a
- Int
v_args)
  -- If these patterns match then we know that:
  --   * loopification optimisation is turned on
  --   * function is performing a self-recursive call in a tail position
  --   * number of non-void parameters of the function matches functions arity.
  -- See Note [Self-recursive tail calls] and Note [Void arguments in
  -- self-recursive tail calls] in GHC.StgToCmm.Expr for more details
  = BlockId -> [LocalReg] -> CallMethod
JumpToIt BlockId
block_id [LocalReg]
args

getCallMethod DynFlags
dflags Name
name Id
id (LFReEntrant TopLevelFlag
_ OneShotInfo
_ Int
arity Bool
_ ArgDescr
_) Int
n_args Int
_v_args CgLoc
_cg_loc
              Maybe SelfLoopInfo
_self_loop_info
  | Int
n_args Int -> Int -> Bool
forall a. Eq a => a -> a -> Bool
== Int
0 -- No args at all
  Bool -> Bool -> Bool
&& Bool -> Bool
not (GeneralFlag -> DynFlags -> Bool
gopt GeneralFlag
Opt_SccProfilingOn DynFlags
dflags)
     -- See Note [Evaluating functions with profiling] in rts/Apply.cmm
  = ASSERT( arity /= 0 ) ReturnIt
  | Int
n_args Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
< Int
arity = CallMethod
SlowCall        -- Not enough args
  | Bool
otherwise      = CLabel -> Int -> CallMethod
DirectEntry (DynFlags -> Name -> CafInfo -> CLabel
enterIdLabel DynFlags
dflags Name
name (Id -> CafInfo
idCafInfo Id
id)) Int
arity

getCallMethod DynFlags
_ Name
_name Id
_ LambdaFormInfo
LFUnlifted Int
n_args Int
_v_args CgLoc
_cg_loc Maybe SelfLoopInfo
_self_loop_info
  = ASSERT( n_args == 0 ) ReturnIt

getCallMethod DynFlags
_ Name
_name Id
_ (LFCon DataCon
_) Int
n_args Int
_v_args CgLoc
_cg_loc Maybe SelfLoopInfo
_self_loop_info
  = ASSERT( n_args == 0 ) ReturnIt
    -- n_args=0 because it'd be ill-typed to apply a saturated
    --          constructor application to anything

getCallMethod DynFlags
dflags Name
name Id
id (LFThunk TopLevelFlag
_ Bool
_ Bool
updatable StandardFormInfo
std_form_info Bool
is_fun)
              Int
n_args Int
_v_args CgLoc
_cg_loc Maybe SelfLoopInfo
_self_loop_info
  | Bool
is_fun      -- it *might* be a function, so we must "call" it (which is always safe)
  = CallMethod
SlowCall    -- We cannot just enter it [in eval/apply, the entry code
                -- is the fast-entry code]

  -- Since is_fun is False, we are *definitely* looking at a data value
  | Bool
updatable Bool -> Bool -> Bool
|| GeneralFlag -> DynFlags -> Bool
gopt GeneralFlag
Opt_Ticky DynFlags
dflags -- to catch double entry
      {- OLD: || opt_SMP
         I decided to remove this, because in SMP mode it doesn't matter
         if we enter the same thunk multiple times, so the optimisation
         of jumping directly to the entry code is still valid.  --SDM
        -}
  = CallMethod
EnterIt

  -- even a non-updatable selector thunk can be updated by the garbage
  -- collector, so we must enter it. (#8817)
  | SelectorThunk{} <- StandardFormInfo
std_form_info
  = CallMethod
EnterIt

    -- We used to have ASSERT( n_args == 0 ), but actually it is
    -- possible for the optimiser to generate
    --   let bot :: Int = error Int "urk"
    --   in (bot `cast` unsafeCoerce Int (Int -> Int)) 3
    -- This happens as a result of the case-of-error transformation
    -- So the right thing to do is just to enter the thing

  | Bool
otherwise        -- Jump direct to code for single-entry thunks
  = ASSERT( n_args == 0 )
    CLabel -> Int -> CallMethod
DirectEntry (DynFlags -> Name -> CafInfo -> StandardFormInfo -> Bool -> CLabel
thunkEntryLabel DynFlags
dflags Name
name (Id -> CafInfo
idCafInfo Id
id) StandardFormInfo
std_form_info
                Bool
updatable) Int
0

getCallMethod DynFlags
_ Name
_name Id
_ (LFUnknown Bool
True) Int
_n_arg Int
_v_args CgLoc
_cg_locs Maybe SelfLoopInfo
_self_loop_info
  = CallMethod
SlowCall -- might be a function

getCallMethod DynFlags
_ Name
name Id
_ (LFUnknown Bool
False) Int
n_args Int
_v_args CgLoc
_cg_loc Maybe SelfLoopInfo
_self_loop_info
  = ASSERT2( n_args == 0, ppr name <+> ppr n_args )
    CallMethod
EnterIt -- Not a function

getCallMethod DynFlags
_ Name
_name Id
_ LambdaFormInfo
LFLetNoEscape Int
_n_args Int
_v_args (LneLoc BlockId
blk_id [LocalReg]
lne_regs)
              Maybe SelfLoopInfo
_self_loop_info
  = BlockId -> [LocalReg] -> CallMethod
JumpToIt BlockId
blk_id [LocalReg]
lne_regs

getCallMethod DynFlags
_ Name
_ Id
_ LambdaFormInfo
_ Int
_ Int
_ CgLoc
_ Maybe SelfLoopInfo
_ = String -> CallMethod
forall a. String -> a
panic String
"Unknown call method"

-----------------------------------------------------------------------------
--              Data types for closure information
-----------------------------------------------------------------------------


{- ClosureInfo: information about a binding

   We make a ClosureInfo for each let binding (both top level and not),
   but not bindings for data constructors: for those we build a CmmInfoTable
   directly (see mkDataConInfoTable).

   To a first approximation:
       ClosureInfo = (LambdaFormInfo, CmmInfoTable)

   A ClosureInfo has enough information
     a) to construct the info table itself, and build other things
        related to the binding (e.g. slow entry points for a function)
     b) to allocate a closure containing that info pointer (i.e.
           it knows the info table label)
-}

data ClosureInfo
  = ClosureInfo {
        ClosureInfo -> Name
closureName :: !Name,           -- The thing bound to this closure
           -- we don't really need this field: it's only used in generating
           -- code for ticky and profiling, and we could pass the information
           -- around separately, but it doesn't do much harm to keep it here.

        ClosureInfo -> LambdaFormInfo
closureLFInfo :: !LambdaFormInfo, -- NOTE: not an LFCon
          -- this tells us about what the closure contains: it's right-hand-side.

          -- the rest is just an unpacked CmmInfoTable.
        ClosureInfo -> CLabel
closureInfoLabel :: !CLabel,
        ClosureInfo -> SMRep
closureSMRep     :: !SMRep,          -- representation used by storage mgr
        ClosureInfo -> ProfilingInfo
closureProf      :: !ProfilingInfo
    }

-- | Convert from 'ClosureInfo' to 'CmmInfoTable'.
mkCmmInfo :: ClosureInfo -> Id -> CostCentreStack -> CmmInfoTable
mkCmmInfo :: ClosureInfo -> Id -> CostCentreStack -> CmmInfoTable
mkCmmInfo ClosureInfo {Name
SMRep
CLabel
ProfilingInfo
LambdaFormInfo
closureProf :: ProfilingInfo
closureSMRep :: SMRep
closureInfoLabel :: CLabel
closureLFInfo :: LambdaFormInfo
closureName :: Name
closureProf :: ClosureInfo -> ProfilingInfo
closureSMRep :: ClosureInfo -> SMRep
closureInfoLabel :: ClosureInfo -> CLabel
closureName :: ClosureInfo -> Name
closureLFInfo :: ClosureInfo -> LambdaFormInfo
..} Id
id CostCentreStack
ccs
  = CmmInfoTable :: CLabel
-> SMRep
-> ProfilingInfo
-> Maybe CLabel
-> Maybe (Id, CostCentreStack)
-> CmmInfoTable
CmmInfoTable { cit_lbl :: CLabel
cit_lbl  = CLabel
closureInfoLabel
                 , cit_rep :: SMRep
cit_rep  = SMRep
closureSMRep
                 , cit_prof :: ProfilingInfo
cit_prof = ProfilingInfo
closureProf
                 , cit_srt :: Maybe CLabel
cit_srt  = Maybe CLabel
forall a. Maybe a
Nothing
                 , cit_clo :: Maybe (Id, CostCentreStack)
cit_clo  = if SMRep -> Bool
isStaticRep SMRep
closureSMRep
                                then (Id, CostCentreStack) -> Maybe (Id, CostCentreStack)
forall a. a -> Maybe a
Just (Id
id,CostCentreStack
ccs)
                                else Maybe (Id, CostCentreStack)
forall a. Maybe a
Nothing }

--------------------------------------
--        Building ClosureInfos
--------------------------------------

mkClosureInfo :: DynFlags
              -> Bool                -- Is static
              -> Id
              -> LambdaFormInfo
              -> Int -> Int        -- Total and pointer words
              -> String         -- String descriptor
              -> ClosureInfo
mkClosureInfo :: DynFlags
-> Bool
-> Id
-> LambdaFormInfo
-> Int
-> Int
-> String
-> ClosureInfo
mkClosureInfo DynFlags
dflags Bool
is_static Id
id LambdaFormInfo
lf_info Int
tot_wds Int
ptr_wds String
val_descr
  = ClosureInfo :: Name
-> LambdaFormInfo
-> CLabel
-> SMRep
-> ProfilingInfo
-> ClosureInfo
ClosureInfo { closureName :: Name
closureName      = Name
name
                , closureLFInfo :: LambdaFormInfo
closureLFInfo    = LambdaFormInfo
lf_info
                , closureInfoLabel :: CLabel
closureInfoLabel = CLabel
info_lbl   -- These three fields are
                , closureSMRep :: SMRep
closureSMRep     = SMRep
sm_rep     -- (almost) an info table
                , closureProf :: ProfilingInfo
closureProf      = ProfilingInfo
prof }     -- (we don't have an SRT yet)
  where
    name :: Name
name       = Id -> Name
idName Id
id
    sm_rep :: SMRep
sm_rep     = DynFlags -> Bool -> Int -> Int -> ClosureTypeInfo -> SMRep
mkHeapRep DynFlags
dflags Bool
is_static Int
ptr_wds Int
nonptr_wds (LambdaFormInfo -> ClosureTypeInfo
lfClosureType LambdaFormInfo
lf_info)
    prof :: ProfilingInfo
prof       = DynFlags -> Id -> String -> ProfilingInfo
mkProfilingInfo DynFlags
dflags Id
id String
val_descr
    nonptr_wds :: Int
nonptr_wds = Int
tot_wds Int -> Int -> Int
forall a. Num a => a -> a -> a
- Int
ptr_wds

    info_lbl :: CLabel
info_lbl = Id -> LambdaFormInfo -> CLabel
mkClosureInfoTableLabel Id
id LambdaFormInfo
lf_info

--------------------------------------
--   Other functions over ClosureInfo
--------------------------------------

-- Eager blackholing is normally disabled, but can be turned on with
-- -feager-blackholing.  When it is on, we replace the info pointer of
-- the thunk with stg_EAGER_BLACKHOLE_info on entry.

-- If we wanted to do eager blackholing with slop filling,
-- we'd need to do it at the *end* of a basic block, otherwise
-- we overwrite the free variables in the thunk that we still
-- need.  We have a patch for this from Andy Cheadle, but not
-- incorporated yet. --SDM [6/2004]
--
-- Previously, eager blackholing was enabled when ticky-ticky
-- was on. But it didn't work, and it wasn't strictly necessary
-- to bring back minimal ticky-ticky, so now EAGER_BLACKHOLING
-- is unconditionally disabled. -- krc 1/2007
--
-- Static closures are never themselves black-holed.

blackHoleOnEntry :: ClosureInfo -> Bool
blackHoleOnEntry :: ClosureInfo -> Bool
blackHoleOnEntry ClosureInfo
cl_info
  | SMRep -> Bool
isStaticRep (ClosureInfo -> SMRep
closureSMRep ClosureInfo
cl_info)
  = Bool
False        -- Never black-hole a static closure

  | Bool
otherwise
  = case ClosureInfo -> LambdaFormInfo
closureLFInfo ClosureInfo
cl_info of
      LFReEntrant {}            -> Bool
False
      LambdaFormInfo
LFLetNoEscape             -> Bool
False
      LFThunk TopLevelFlag
_ Bool
_no_fvs Bool
upd StandardFormInfo
_ Bool
_ -> Bool
upd   -- See Note [Black-holing non-updatable thunks]
      LambdaFormInfo
_other -> String -> Bool
forall a. String -> a
panic String
"blackHoleOnEntry"

{- Note [Black-holing non-updatable thunks]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
We must not black-hole non-updatable (single-entry) thunks otherwise
we run into issues like #10414. Specifically:

  * There is no reason to black-hole a non-updatable thunk: it should
    not be competed for by multiple threads

  * It could, conceivably, cause a space leak if we don't black-hole
    it, if there was a live but never-followed pointer pointing to it.
    Let's hope that doesn't happen.

  * It is dangerous to black-hole a non-updatable thunk because
     - is not updated (of course)
     - hence, if it is black-holed and another thread tries to evaluate
       it, that thread will block forever
    This actually happened in #10414.  So we do not black-hole
    non-updatable thunks.

  * How could two threads evaluate the same non-updatable (single-entry)
    thunk?  See Reid Barton's example below.

  * Only eager blackholing could possibly black-hole a non-updatable
    thunk, because lazy black-holing only affects thunks with an
    update frame on the stack.

Here is and example due to Reid Barton (#10414):
    x = \u []  concat [[1], []]
with the following definitions,

    concat x = case x of
        []       -> []
        (:) x xs -> (++) x (concat xs)

    (++) xs ys = case xs of
        []         -> ys
        (:) x rest -> (:) x ((++) rest ys)

Where we use the syntax @\u []@ to denote an updatable thunk and @\s []@ to
denote a single-entry (i.e. non-updatable) thunk. After a thread evaluates @x@
to WHNF and calls @(++)@ the heap will contain the following thunks,

    x = 1 : y
    y = \u []  (++) [] z
    z = \s []  concat []

Now that the stage is set, consider the follow evaluations by two racing threads
A and B,

  1. Both threads enter @y@ before either is able to replace it with an
     indirection

  2. Thread A does the case analysis in @(++)@ and consequently enters @z@,
     replacing it with a black-hole

  3. At some later point thread B does the same case analysis and also attempts
     to enter @z@. However, it finds that it has been replaced with a black-hole
     so it blocks.

  4. Thread A eventually finishes evaluating @z@ (to @[]@) and updates @y@
     accordingly. It does *not* update @z@, however, as it is single-entry. This
     leaves Thread B blocked forever on a black-hole which will never be
     updated.

To avoid this sort of condition we never black-hole non-updatable thunks.
-}

isStaticClosure :: ClosureInfo -> Bool
isStaticClosure :: ClosureInfo -> Bool
isStaticClosure ClosureInfo
cl_info = SMRep -> Bool
isStaticRep (ClosureInfo -> SMRep
closureSMRep ClosureInfo
cl_info)

closureUpdReqd :: ClosureInfo -> Bool
closureUpdReqd :: ClosureInfo -> Bool
closureUpdReqd ClosureInfo{ closureLFInfo :: ClosureInfo -> LambdaFormInfo
closureLFInfo = LambdaFormInfo
lf_info } = LambdaFormInfo -> Bool
lfUpdatable LambdaFormInfo
lf_info

lfUpdatable :: LambdaFormInfo -> Bool
lfUpdatable :: LambdaFormInfo -> Bool
lfUpdatable (LFThunk TopLevelFlag
_ Bool
_ Bool
upd StandardFormInfo
_ Bool
_)  = Bool
upd
lfUpdatable LambdaFormInfo
_ = Bool
False

closureSingleEntry :: ClosureInfo -> Bool
closureSingleEntry :: ClosureInfo -> Bool
closureSingleEntry (ClosureInfo { closureLFInfo :: ClosureInfo -> LambdaFormInfo
closureLFInfo = LFThunk TopLevelFlag
_ Bool
_ Bool
upd StandardFormInfo
_ Bool
_}) = Bool -> Bool
not Bool
upd
closureSingleEntry (ClosureInfo { closureLFInfo :: ClosureInfo -> LambdaFormInfo
closureLFInfo = LFReEntrant TopLevelFlag
_ OneShotInfo
OneShotLam Int
_ Bool
_ ArgDescr
_}) = Bool
True
closureSingleEntry ClosureInfo
_ = Bool
False

closureReEntrant :: ClosureInfo -> Bool
closureReEntrant :: ClosureInfo -> Bool
closureReEntrant (ClosureInfo { closureLFInfo :: ClosureInfo -> LambdaFormInfo
closureLFInfo = LFReEntrant {} }) = Bool
True
closureReEntrant ClosureInfo
_ = Bool
False

closureFunInfo :: ClosureInfo -> Maybe (RepArity, ArgDescr)
closureFunInfo :: ClosureInfo -> Maybe (Int, ArgDescr)
closureFunInfo (ClosureInfo { closureLFInfo :: ClosureInfo -> LambdaFormInfo
closureLFInfo = LambdaFormInfo
lf_info }) = LambdaFormInfo -> Maybe (Int, ArgDescr)
lfFunInfo LambdaFormInfo
lf_info

lfFunInfo :: LambdaFormInfo ->  Maybe (RepArity, ArgDescr)
lfFunInfo :: LambdaFormInfo -> Maybe (Int, ArgDescr)
lfFunInfo (LFReEntrant TopLevelFlag
_ OneShotInfo
_ Int
arity Bool
_ ArgDescr
arg_desc)  = (Int, ArgDescr) -> Maybe (Int, ArgDescr)
forall a. a -> Maybe a
Just (Int
arity, ArgDescr
arg_desc)
lfFunInfo LambdaFormInfo
_                                   = Maybe (Int, ArgDescr)
forall a. Maybe a
Nothing

funTag :: DynFlags -> ClosureInfo -> DynTag
funTag :: DynFlags -> ClosureInfo -> Int
funTag DynFlags
dflags (ClosureInfo { closureLFInfo :: ClosureInfo -> LambdaFormInfo
closureLFInfo = LambdaFormInfo
lf_info })
    = DynFlags -> LambdaFormInfo -> Int
lfDynTag DynFlags
dflags LambdaFormInfo
lf_info

isToplevClosure :: ClosureInfo -> Bool
isToplevClosure :: ClosureInfo -> Bool
isToplevClosure (ClosureInfo { closureLFInfo :: ClosureInfo -> LambdaFormInfo
closureLFInfo = LambdaFormInfo
lf_info })
  = case LambdaFormInfo
lf_info of
      LFReEntrant TopLevelFlag
TopLevel OneShotInfo
_ Int
_ Bool
_ ArgDescr
_ -> Bool
True
      LFThunk TopLevelFlag
TopLevel Bool
_ Bool
_ StandardFormInfo
_ Bool
_     -> Bool
True
      LambdaFormInfo
_other                       -> Bool
False

--------------------------------------
--   Label generation
--------------------------------------

staticClosureLabel :: ClosureInfo -> CLabel
staticClosureLabel :: ClosureInfo -> CLabel
staticClosureLabel = CLabel -> CLabel
toClosureLbl (CLabel -> CLabel)
-> (ClosureInfo -> CLabel) -> ClosureInfo -> CLabel
forall b c a. (b -> c) -> (a -> b) -> a -> c
.  ClosureInfo -> CLabel
closureInfoLabel

closureSlowEntryLabel :: ClosureInfo -> CLabel
closureSlowEntryLabel :: ClosureInfo -> CLabel
closureSlowEntryLabel = CLabel -> CLabel
toSlowEntryLbl (CLabel -> CLabel)
-> (ClosureInfo -> CLabel) -> ClosureInfo -> CLabel
forall b c a. (b -> c) -> (a -> b) -> a -> c
. ClosureInfo -> CLabel
closureInfoLabel

closureLocalEntryLabel :: DynFlags -> ClosureInfo -> CLabel
closureLocalEntryLabel :: DynFlags -> ClosureInfo -> CLabel
closureLocalEntryLabel DynFlags
dflags
  | DynFlags -> Bool
tablesNextToCode DynFlags
dflags = CLabel -> CLabel
toInfoLbl  (CLabel -> CLabel)
-> (ClosureInfo -> CLabel) -> ClosureInfo -> CLabel
forall b c a. (b -> c) -> (a -> b) -> a -> c
. ClosureInfo -> CLabel
closureInfoLabel
  | Bool
otherwise               = CLabel -> CLabel
toEntryLbl (CLabel -> CLabel)
-> (ClosureInfo -> CLabel) -> ClosureInfo -> CLabel
forall b c a. (b -> c) -> (a -> b) -> a -> c
. ClosureInfo -> CLabel
closureInfoLabel

mkClosureInfoTableLabel :: Id -> LambdaFormInfo -> CLabel
mkClosureInfoTableLabel :: Id -> LambdaFormInfo -> CLabel
mkClosureInfoTableLabel Id
id LambdaFormInfo
lf_info
  = case LambdaFormInfo
lf_info of
        LFThunk TopLevelFlag
_ Bool
_ Bool
upd_flag (SelectorThunk Int
offset) Bool
_
                      -> Bool -> Int -> CLabel
mkSelectorInfoLabel Bool
upd_flag Int
offset

        LFThunk TopLevelFlag
_ Bool
_ Bool
upd_flag (ApThunk Int
arity) Bool
_
                      -> Bool -> Int -> CLabel
mkApInfoTableLabel Bool
upd_flag Int
arity

        LFThunk{}     -> Name -> CafInfo -> CLabel
std_mk_lbl Name
name CafInfo
cafs
        LFReEntrant{} -> Name -> CafInfo -> CLabel
std_mk_lbl Name
name CafInfo
cafs
        LambdaFormInfo
_other        -> String -> CLabel
forall a. String -> a
panic String
"closureInfoTableLabel"

  where
    name :: Name
name = Id -> Name
idName Id
id

    std_mk_lbl :: Name -> CafInfo -> CLabel
std_mk_lbl | Bool
is_local  = Name -> CafInfo -> CLabel
mkLocalInfoTableLabel
               | Bool
otherwise = Name -> CafInfo -> CLabel
mkInfoTableLabel

    cafs :: CafInfo
cafs     = Id -> CafInfo
idCafInfo Id
id
    is_local :: Bool
is_local = Id -> Bool
isDataConWorkId Id
id
       -- Make the _info pointer for the implicit datacon worker
       -- binding local. The reason we can do this is that importing
       -- code always either uses the _closure or _con_info. By the
       -- invariants in CorePrep anything else gets eta expanded.


thunkEntryLabel :: DynFlags -> Name -> CafInfo -> StandardFormInfo -> Bool -> CLabel
-- thunkEntryLabel is a local help function, not exported.  It's used from
-- getCallMethod.
thunkEntryLabel :: DynFlags -> Name -> CafInfo -> StandardFormInfo -> Bool -> CLabel
thunkEntryLabel DynFlags
dflags Name
_thunk_id CafInfo
_ (ApThunk Int
arity) Bool
upd_flag
  = DynFlags -> Bool -> Int -> CLabel
enterApLabel DynFlags
dflags Bool
upd_flag Int
arity
thunkEntryLabel DynFlags
dflags Name
_thunk_id CafInfo
_ (SelectorThunk Int
offset) Bool
upd_flag
  = DynFlags -> Bool -> Int -> CLabel
enterSelectorLabel DynFlags
dflags Bool
upd_flag Int
offset
thunkEntryLabel DynFlags
dflags Name
thunk_id CafInfo
c StandardFormInfo
_ Bool
_
  = DynFlags -> Name -> CafInfo -> CLabel
enterIdLabel DynFlags
dflags Name
thunk_id CafInfo
c

enterApLabel :: DynFlags -> Bool -> Arity -> CLabel
enterApLabel :: DynFlags -> Bool -> Int -> CLabel
enterApLabel DynFlags
dflags Bool
is_updatable Int
arity
  | DynFlags -> Bool
tablesNextToCode DynFlags
dflags = Bool -> Int -> CLabel
mkApInfoTableLabel Bool
is_updatable Int
arity
  | Bool
otherwise               = Bool -> Int -> CLabel
mkApEntryLabel Bool
is_updatable Int
arity

enterSelectorLabel :: DynFlags -> Bool -> WordOff -> CLabel
enterSelectorLabel :: DynFlags -> Bool -> Int -> CLabel
enterSelectorLabel DynFlags
dflags Bool
upd_flag Int
offset
  | DynFlags -> Bool
tablesNextToCode DynFlags
dflags = Bool -> Int -> CLabel
mkSelectorInfoLabel Bool
upd_flag Int
offset
  | Bool
otherwise               = Bool -> Int -> CLabel
mkSelectorEntryLabel Bool
upd_flag Int
offset

enterIdLabel :: DynFlags -> Name -> CafInfo -> CLabel
enterIdLabel :: DynFlags -> Name -> CafInfo -> CLabel
enterIdLabel DynFlags
dflags Name
id CafInfo
c
  | DynFlags -> Bool
tablesNextToCode DynFlags
dflags = Name -> CafInfo -> CLabel
mkInfoTableLabel Name
id CafInfo
c
  | Bool
otherwise               = Name -> CafInfo -> CLabel
mkEntryLabel Name
id CafInfo
c


--------------------------------------
--   Profiling
--------------------------------------

-- Profiling requires two pieces of information to be determined for
-- each closure's info table --- description and type.

-- The description is stored directly in the @CClosureInfoTable@ when the
-- info table is built.

-- The type is determined from the type information stored with the @Id@
-- in the closure info using @closureTypeDescr@.

mkProfilingInfo :: DynFlags -> Id -> String -> ProfilingInfo
mkProfilingInfo :: DynFlags -> Id -> String -> ProfilingInfo
mkProfilingInfo DynFlags
dflags Id
id String
val_descr
  | Bool -> Bool
not (GeneralFlag -> DynFlags -> Bool
gopt GeneralFlag
Opt_SccProfilingOn DynFlags
dflags) = ProfilingInfo
NoProfilingInfo
  | Bool
otherwise = ConstrDescription -> ConstrDescription -> ProfilingInfo
ProfilingInfo ConstrDescription
ty_descr_w8 (String -> ConstrDescription
BS8.pack String
val_descr)
  where
    ty_descr_w8 :: ConstrDescription
ty_descr_w8  = String -> ConstrDescription
BS8.pack (Type -> String
getTyDescription (Id -> Type
idType Id
id))

getTyDescription :: Type -> String
getTyDescription :: Type -> String
getTyDescription Type
ty
  = case (Type -> ([Id], ThetaType, Type)
tcSplitSigmaTy Type
ty) of { ([Id]
_, ThetaType
_, Type
tau_ty) ->
    case Type
tau_ty of
      TyVarTy Id
_              -> String
"*"
      AppTy Type
fun Type
_            -> Type -> String
getTyDescription Type
fun
      TyConApp TyCon
tycon ThetaType
_       -> TyCon -> String
forall a. NamedThing a => a -> String
getOccString TyCon
tycon
      FunTy {}              -> Char
'-' Char -> ShowS
forall a. a -> [a] -> [a]
: Type -> String
fun_result Type
tau_ty
      ForAllTy TyCoVarBinder
_  Type
ty         -> Type -> String
getTyDescription Type
ty
      LitTy TyLit
n                -> TyLit -> String
getTyLitDescription TyLit
n
      CastTy Type
ty KindCoercion
_            -> Type -> String
getTyDescription Type
ty
      CoercionTy KindCoercion
co          -> String -> SDoc -> String
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"getTyDescription" (KindCoercion -> SDoc
forall a. Outputable a => a -> SDoc
ppr KindCoercion
co)
    }
  where
    fun_result :: Type -> String
fun_result (FunTy { ft_res :: Type -> Type
ft_res = Type
res }) = Char
'>' Char -> ShowS
forall a. a -> [a] -> [a]
: Type -> String
fun_result Type
res
    fun_result Type
other                    = Type -> String
getTyDescription Type
other

getTyLitDescription :: TyLit -> String
getTyLitDescription :: TyLit -> String
getTyLitDescription TyLit
l =
  case TyLit
l of
    NumTyLit Integer
n -> Integer -> String
forall a. Show a => a -> String
show Integer
n
    StrTyLit FastString
n -> FastString -> String
forall a. Show a => a -> String
show FastString
n

--------------------------------------
--   CmmInfoTable-related things
--------------------------------------

mkDataConInfoTable :: DynFlags -> DataCon -> Bool -> Int -> Int -> CmmInfoTable
mkDataConInfoTable :: DynFlags -> DataCon -> Bool -> Int -> Int -> CmmInfoTable
mkDataConInfoTable DynFlags
dflags DataCon
data_con Bool
is_static Int
ptr_wds Int
nonptr_wds
 = CmmInfoTable :: CLabel
-> SMRep
-> ProfilingInfo
-> Maybe CLabel
-> Maybe (Id, CostCentreStack)
-> CmmInfoTable
CmmInfoTable { cit_lbl :: CLabel
cit_lbl  = CLabel
info_lbl
                , cit_rep :: SMRep
cit_rep  = SMRep
sm_rep
                , cit_prof :: ProfilingInfo
cit_prof = ProfilingInfo
prof
                , cit_srt :: Maybe CLabel
cit_srt  = Maybe CLabel
forall a. Maybe a
Nothing
                , cit_clo :: Maybe (Id, CostCentreStack)
cit_clo  = Maybe (Id, CostCentreStack)
forall a. Maybe a
Nothing }
 where
   name :: Name
name = DataCon -> Name
dataConName DataCon
data_con
   info_lbl :: CLabel
info_lbl = Name -> CafInfo -> CLabel
mkConInfoTableLabel Name
name CafInfo
NoCafRefs
   sm_rep :: SMRep
sm_rep = DynFlags -> Bool -> Int -> Int -> ClosureTypeInfo -> SMRep
mkHeapRep DynFlags
dflags Bool
is_static Int
ptr_wds Int
nonptr_wds ClosureTypeInfo
cl_type
   cl_type :: ClosureTypeInfo
cl_type = Int -> ConstrDescription -> ClosureTypeInfo
Constr (DataCon -> Int
dataConTagZ DataCon
data_con) (DataCon -> ConstrDescription
dataConIdentity DataCon
data_con)
                  -- We keep the *zero-indexed* tag in the srt_len field
                  -- of the info table of a data constructor.

   prof :: ProfilingInfo
prof | Bool -> Bool
not (GeneralFlag -> DynFlags -> Bool
gopt GeneralFlag
Opt_SccProfilingOn DynFlags
dflags) = ProfilingInfo
NoProfilingInfo
        | Bool
otherwise                            = ConstrDescription -> ConstrDescription -> ProfilingInfo
ProfilingInfo ConstrDescription
ty_descr ConstrDescription
val_descr

   ty_descr :: ConstrDescription
ty_descr  = String -> ConstrDescription
BS8.pack (String -> ConstrDescription) -> String -> ConstrDescription
forall a b. (a -> b) -> a -> b
$ OccName -> String
occNameString (OccName -> String) -> OccName -> String
forall a b. (a -> b) -> a -> b
$ TyCon -> OccName
forall a. NamedThing a => a -> OccName
getOccName (TyCon -> OccName) -> TyCon -> OccName
forall a b. (a -> b) -> a -> b
$ DataCon -> TyCon
dataConTyCon DataCon
data_con
   val_descr :: ConstrDescription
val_descr = String -> ConstrDescription
BS8.pack (String -> ConstrDescription) -> String -> ConstrDescription
forall a b. (a -> b) -> a -> b
$ OccName -> String
occNameString (OccName -> String) -> OccName -> String
forall a b. (a -> b) -> a -> b
$ DataCon -> OccName
forall a. NamedThing a => a -> OccName
getOccName DataCon
data_con

-- We need a black-hole closure info to pass to @allocDynClosure@ when we
-- want to allocate the black hole on entry to a CAF.

cafBlackHoleInfoTable :: CmmInfoTable
cafBlackHoleInfoTable :: CmmInfoTable
cafBlackHoleInfoTable
  = CmmInfoTable :: CLabel
-> SMRep
-> ProfilingInfo
-> Maybe CLabel
-> Maybe (Id, CostCentreStack)
-> CmmInfoTable
CmmInfoTable { cit_lbl :: CLabel
cit_lbl  = CLabel
mkCAFBlackHoleInfoTableLabel
                 , cit_rep :: SMRep
cit_rep  = SMRep
blackHoleRep
                 , cit_prof :: ProfilingInfo
cit_prof = ProfilingInfo
NoProfilingInfo
                 , cit_srt :: Maybe CLabel
cit_srt  = Maybe CLabel
forall a. Maybe a
Nothing
                 , cit_clo :: Maybe (Id, CostCentreStack)
cit_clo  = Maybe (Id, CostCentreStack)
forall a. Maybe a
Nothing }

indStaticInfoTable :: CmmInfoTable
indStaticInfoTable :: CmmInfoTable
indStaticInfoTable
  = CmmInfoTable :: CLabel
-> SMRep
-> ProfilingInfo
-> Maybe CLabel
-> Maybe (Id, CostCentreStack)
-> CmmInfoTable
CmmInfoTable { cit_lbl :: CLabel
cit_lbl  = CLabel
mkIndStaticInfoLabel
                 , cit_rep :: SMRep
cit_rep  = SMRep
indStaticRep
                 , cit_prof :: ProfilingInfo
cit_prof = ProfilingInfo
NoProfilingInfo
                 , cit_srt :: Maybe CLabel
cit_srt  = Maybe CLabel
forall a. Maybe a
Nothing
                 , cit_clo :: Maybe (Id, CostCentreStack)
cit_clo  = Maybe (Id, CostCentreStack)
forall a. Maybe a
Nothing }

staticClosureNeedsLink :: Bool -> CmmInfoTable -> Bool
-- A static closure needs a link field to aid the GC when traversing
-- the static closure graph.  But it only needs such a field if either
--        a) it has an SRT
--        b) it's a constructor with one or more pointer fields
-- In case (b), the constructor's fields themselves play the role
-- of the SRT.
staticClosureNeedsLink :: Bool -> CmmInfoTable -> Bool
staticClosureNeedsLink Bool
has_srt CmmInfoTable{ cit_rep :: CmmInfoTable -> SMRep
cit_rep = SMRep
smrep }
  | SMRep -> Bool
isConRep SMRep
smrep         = Bool -> Bool
not (SMRep -> Bool
isStaticNoCafCon SMRep
smrep)
  | Bool
otherwise              = Bool
has_srt