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| author | Ben Gamari <ben@smart-cactus.org> | 2019-11-19 11:43:30 -0500 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2019-12-03 07:11:33 -0500 |
| commit | 705a16df02411ec2445c9a254396a93cabe559ef (patch) | |
| tree | aae70d73be2d785fd85951ef3813673f2b37e695 /compiler | |
| parent | 5a4b8d0cf2ff83d1a04826b9624fffec7b9a5683 (diff) | |
| download | haskell-705a16df02411ec2445c9a254396a93cabe559ef.tar.gz | |
Make BCO# lifted
In #17424 Simon PJ noted that there is a potentially unsafe occurrence
of unsafeCoerce#, coercing from an unlifted to lifted type. However,
nowhere in the compiler do we assume that a BCO# is not a thunk.
Moreover, in the case of a CAF the result returned by `createBCO` *will*
be a thunk (as noted in [Updatable CAF BCOs]). Consequently it seems
better to rather make BCO# a lifted type and rename it to BCO.
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/prelude/TysPrim.hs | 7 | ||||
| -rw-r--r-- | compiler/prelude/primops.txt.pp | 6 |
2 files changed, 8 insertions, 5 deletions
diff --git a/compiler/prelude/TysPrim.hs b/compiler/prelude/TysPrim.hs index 79a30482b0..a023c430fe 100644 --- a/compiler/prelude/TysPrim.hs +++ b/compiler/prelude/TysPrim.hs @@ -239,7 +239,7 @@ tVarPrimTyConName = mkPrimTc (fsLit "TVar#") tVarPrimTyConKey tVarPr stablePtrPrimTyConName = mkPrimTc (fsLit "StablePtr#") stablePtrPrimTyConKey stablePtrPrimTyCon stableNamePrimTyConName = mkPrimTc (fsLit "StableName#") stableNamePrimTyConKey stableNamePrimTyCon compactPrimTyConName = mkPrimTc (fsLit "Compact#") compactPrimTyConKey compactPrimTyCon -bcoPrimTyConName = mkPrimTc (fsLit "BCO#") bcoPrimTyConKey bcoPrimTyCon +bcoPrimTyConName = mkPrimTc (fsLit "BCO") bcoPrimTyConKey bcoPrimTyCon weakPrimTyConName = mkPrimTc (fsLit "Weak#") weakPrimTyConKey weakPrimTyCon threadIdPrimTyConName = mkPrimTc (fsLit "ThreadId#") threadIdPrimTyConKey threadIdPrimTyCon @@ -1052,10 +1052,13 @@ compactPrimTy = mkTyConTy compactPrimTyCon ************************************************************************ -} +-- Unlike most other primitive types, BCO is lifted. This is because in +-- general a BCO may be a thunk for the reasons given in Note [Updatable CAF +-- BCOs] in GHCi.CreateBCO. bcoPrimTy :: Type bcoPrimTy = mkTyConTy bcoPrimTyCon bcoPrimTyCon :: TyCon -bcoPrimTyCon = pcPrimTyCon0 bcoPrimTyConName UnliftedRep +bcoPrimTyCon = pcPrimTyCon0 bcoPrimTyConName LiftedRep {- ************************************************************************ diff --git a/compiler/prelude/primops.txt.pp b/compiler/prelude/primops.txt.pp index 0faf180061..de7d498da1 100644 --- a/compiler/prelude/primops.txt.pp +++ b/compiler/prelude/primops.txt.pp @@ -3249,7 +3249,7 @@ section "Bytecode operations" contain a list of instructions and data needed by these instructions.} ------------------------------------------------------------------------ -primtype BCO# +primtype BCO { Primitive bytecode type. } primop AddrToAnyOp "addrToAny#" GenPrimOp @@ -3274,14 +3274,14 @@ primop AnyToAddrOp "anyToAddr#" GenPrimOp code_size = 0 primop MkApUpd0_Op "mkApUpd0#" GenPrimOp - BCO# -> (# a #) + BCO -> (# a #) { Wrap a BCO in a {\tt AP_UPD} thunk which will be updated with the value of the BCO when evaluated. } with out_of_line = True primop NewBCOOp "newBCO#" GenPrimOp - ByteArray# -> ByteArray# -> Array# a -> Int# -> ByteArray# -> State# s -> (# State# s, BCO# #) + ByteArray# -> ByteArray# -> Array# a -> Int# -> ByteArray# -> State# s -> (# State# s, BCO #) { {\tt newBCO\# instrs lits ptrs arity bitmap} creates a new bytecode object. The resulting object encodes a function of the given arity with the instructions encoded in {\tt instrs}, and a static reference table usage bitmap given by |