{-# LANGUAGE TypeSynonymInstances #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}

{- BlockId module should probably go away completely, being superseded by Label -}
module GHC.Cmm.BlockId
  ( BlockId, mkBlockId -- ToDo: BlockId should be abstract, but it isn't yet
  , newBlockId
  , blockLbl, infoTblLbl
  ) where

import GHC.Prelude

import GHC.Cmm.CLabel
import GHC.Data.FastString
import GHC.Types.Id.Info
import GHC.Types.Name
import GHC.Types.Unique
import qualified GHC.Types.Unique.DSM as DSM

import GHC.Cmm.Dataflow.Label (Label, mkHooplLabel)

----------------------------------------------------------------
--- Block Ids, their environments, and their sets

{- Note [Unique BlockId]
~~~~~~~~~~~~~~~~~~~~~~~~
Although a 'BlockId' is a local label, for reasons of implementation,
'BlockId's must be unique within an entire compilation unit.  The reason
is that each local label is mapped to an assembly-language label, and in
most assembly languages allow, a label is visible throughout the entire
compilation unit in which it appears.
-}

type BlockId = Label

mkBlockId :: Unique -> BlockId
mkBlockId :: Unique -> BlockId
mkBlockId Unique
unique = Word64 -> BlockId
mkHooplLabel (Word64 -> BlockId) -> Word64 -> BlockId
forall a b. (a -> b) -> a -> b
$ Unique -> Word64
getKey Unique
unique

-- If the monad unique instance uses a deterministic unique supply, this will
-- give you a deterministic unique. Otherwise, it will not. Note that from Cmm
-- onwards (after deterministic renaming in 'codeGen'), there should only exist
-- deterministic block labels.
newBlockId :: DSM.MonadGetUnique m => m BlockId
newBlockId :: forall (m :: * -> *). MonadGetUnique m => m BlockId
newBlockId = Unique -> BlockId
mkBlockId (Unique -> BlockId) -> m Unique -> m BlockId
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> m Unique
forall (m :: * -> *). MonadGetUnique m => m Unique
DSM.getUniqueM

blockLbl :: BlockId -> CLabel
blockLbl :: BlockId -> CLabel
blockLbl BlockId
label = Unique -> CLabel
mkLocalBlockLabel (BlockId -> Unique
forall a. Uniquable a => a -> Unique
getUnique BlockId
label)

infoTblLbl :: BlockId -> CLabel
infoTblLbl :: BlockId -> CLabel
infoTblLbl BlockId
label
  = Name -> CafInfo -> CLabel
mkBlockInfoTableLabel (Unique -> FastString -> Name
mkFCallName (BlockId -> Unique
forall a. Uniquable a => a -> Unique
getUnique BlockId
label) (String -> FastString
fsLit String
"block")) CafInfo
NoCafRefs