diff options
Diffstat (limited to 'compiler/GHC/Builtin/Uniques.hs')
| -rw-r--r-- | compiler/GHC/Builtin/Uniques.hs | 74 |
1 files changed, 59 insertions, 15 deletions
diff --git a/compiler/GHC/Builtin/Uniques.hs b/compiler/GHC/Builtin/Uniques.hs index e689ca6304..9da937f8c5 100644 --- a/compiler/GHC/Builtin/Uniques.hs +++ b/compiler/GHC/Builtin/Uniques.hs @@ -13,8 +13,8 @@ module GHC.Builtin.Uniques -- * Getting the 'Unique's of 'Name's -- ** Anonymous sums - , mkSumTyConUnique - , mkSumDataConUnique + , mkSumTyConUnique, mkSumDataConUnique + -- ** Tuples -- *** Vanilla , mkTupleTyConUnique @@ -45,6 +45,9 @@ module GHC.Builtin.Uniques , initExitJoinUnique + -- Boxing data types + , mkBoxingTyConUnique, boxingDataConUnique + ) where import GHC.Prelude @@ -60,7 +63,6 @@ import GHC.Data.FastString import GHC.Utils.Outputable import GHC.Utils.Panic -import GHC.Utils.Panic.Plain import Data.Maybe @@ -107,8 +109,9 @@ TypeRep for sum DataCon of arity k and alternative n (zero-based): mkSumTyConUnique :: Arity -> Unique mkSumTyConUnique arity = - assert (arity < 0x3f) $ -- 0x3f since we only have 6 bits to encode the - -- alternative + assertPpr (arity <= 0x3f) (ppr arity) $ + -- 0x3f since we only have 6 bits to encode the + -- alternative mkUnique 'z' (arity `shiftL` 8 .|. 0xfc) mkSumDataConUnique :: ConTagZ -> Arity -> Unique @@ -297,6 +300,7 @@ Allocation of unique supply characters: other a-z: lower case chars for unique supplies. Used so far: a TypeChecking? + b Boxing tycons & datacons c StgToCmm/Renamer d desugarer f AbsC flattener @@ -310,6 +314,27 @@ Allocation of unique supply characters: u Cmm pipeline y GHCi bytecode generator z anonymous sums + +Note [Related uniques for wired-in things] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +* All wired in tycons actually use *two* uniques: + * u: the TyCon itself + * u+1: the TyConRepName of the TyCon (for use with TypeRep) + The "+1" is implemented in tyConRepNameUnique. + If this ever changes, make sure to also change the treatment for boxing tycons. + +* All wired in datacons use *three* uniques: + * u: the DataCon itself + * u+1: its worker Id + * u+2: the TyConRepName of the promoted TyCon + No wired-in datacons have wrappers. + The "+1" is implemented in dataConWorkerUnique and the "+2" is in dataConTyRepNameUnique. + If this ever changes, make sure to also change the treatment for boxing tycons. + +* Because boxing tycons (see Note [Boxing constructors] in GHC.Builtin.Types) + come with both a tycon and a datacon, each one takes up five slots, combining + the two cases above. Getting from the tycon to the datacon (by adding 2) + is implemented in boxingDataConUnique. -} mkAlphaTyVarUnique :: Int -> Unique @@ -351,29 +376,48 @@ mkTcOccUnique fs = mkUnique 'c' (uniqueOfFS fs) initExitJoinUnique :: Unique initExitJoinUnique = mkUnique 's' 0 - -------------------------------------------------- -- Wired-in type constructor keys occupy *two* slots: --- * u: the TyCon itself --- * u+1: the TyConRepName of the TyCon +-- See Note [Related uniques for wired-in things] mkPreludeTyConUnique :: Int -> Unique -mkPreludeTyConUnique i = mkUnique '3' (2*i) +mkPreludeTyConUnique i = mkUnique '3' (2*i) tyConRepNameUnique :: Unique -> Unique tyConRepNameUnique u = incrUnique u -------------------------------------------------- -- Wired-in data constructor keys occupy *three* slots: --- * u: the DataCon itself --- * u+1: its worker Id --- * u+2: the TyConRepName of the promoted TyCon --- Prelude data constructors are too simple to need wrappers. +-- See Note [Related uniques for wired-in things] mkPreludeDataConUnique :: Int -> Unique -mkPreludeDataConUnique i = mkUnique '6' (3*i) -- Must be alphabetic +mkPreludeDataConUnique i = mkUnique '6' (3*i) -- Must be alphabetic --------------------------------------------------- dataConTyRepNameUnique, dataConWorkerUnique :: Unique -> Unique dataConWorkerUnique u = incrUnique u dataConTyRepNameUnique u = stepUnique u 2 + +-------------------------------------------------- +-- The data constructors of RuntimeRep occupy *five* slots: +-- See Note [Related uniques for wired-in things] +-- +-- Example: WordRep +-- +-- * u: the TyCon of the boxing data type WordBox +-- * u+1: the TyConRepName of the boxing data type +-- * u+2: the DataCon for MkWordBox +-- * u+3: the worker id for MkWordBox +-- * u+4: the TyConRepName of the promoted TyCon 'MkWordBox +-- +-- Note carefully that +-- * u,u+1 are in sync with the conventions for +-- wired-in type constructors, above +-- * u+2,u+3,u+4 are in sync with the conventions for +-- wired-in data constructors, above +-- A little delicate! + +mkBoxingTyConUnique :: Int -> Unique +mkBoxingTyConUnique i = mkUnique 'b' (5*i) + +boxingDataConUnique :: Unique -> Unique +boxingDataConUnique u = stepUnique u 2 |