Handle Char#, Addr# in TH quasiquoter (fixes #10620)

DsMeta does not attempt to handle quasiquoted Char# or Addr# values,
which causes expressions like `$([| 'a'# |])` or `$([| "abc"# |])` to
fail
with an `Exotic literal not (yet) handled by Template Haskell` error.

To fix this, the API of `template-haskell` had to be changed so that
`Lit`
now has an extra constructor `CharPrimL` (a `StringPrimL` constructor
already
existed, but it wasn't used). In addition, `DsMeta` has to manipulate
`CoreExpr`s directly that involve `Word8`s. In order to do this,
`Word8` had
to be added as a wired-in type to `TysWiredIn`.

Actually converting from `HsCharPrim` and `HsStringPrim` to `CharPrimL`
and
`StringPrimL`, respectively, is pretty straightforward after that, since
both `HsCharPrim` and `CharPrimL` use `Char` internally, and
`HsStringPrim`
uses a `ByteString` internally, which can easily be converted to
`[Word8]`,
which is what `StringPrimL` uses.

Reviewers: goldfire, austin, simonpj, bgamari

Reviewed By: simonpj, bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D1054

GHC Trac Issues: #10620

1 files changed, 19 insertions, 1 deletions

diff --git a/compiler/prelude/TysWiredIn.hs b/compiler/prelude/TysWiredIn.hs
index 5ab8654f06..f7d08ff1c4 100644
--- a/compiler/prelude/TysWiredIn.hs
+++ b/compiler/prelude/TysWiredIn.hs
@@ -42,6 +42,9 @@ module TysWiredIn (
         -- * Word
         wordTyCon, wordDataCon, wordTyConName, wordTy,
 
+        -- * Word8
+        word8TyCon, word8DataCon, word8TyConName, word8Ty,
+
         -- * List
         listTyCon, listTyCon_RDR, listTyConName, listTyConKey,
         nilDataCon, nilDataConName, nilDataConKey,
@@ -152,6 +155,7 @@ wiredInTyCons = [ unitTyCon     -- Not treated like other tuples, because
               , floatTyCon
               , intTyCon
               , wordTyCon
+              , word8TyCon
               , listTyCon
               , parrTyCon
               , eqTyCon
@@ -198,9 +202,13 @@ listTyConName     = mkWiredInTyConName   BuiltInSyntax gHC_TYPES (fsLit "[]") li
 nilDataConName    = mkWiredInDataConName BuiltInSyntax gHC_TYPES (fsLit "[]") nilDataConKey nilDataCon
 consDataConName   = mkWiredInDataConName BuiltInSyntax gHC_TYPES (fsLit ":") consDataConKey consDataCon
 
-wordTyConName, wordDataConName, floatTyConName, floatDataConName, doubleTyConName, doubleDataConName :: Name
+wordTyConName, wordDataConName, word8TyConName, word8DataConName :: Name
 wordTyConName      = mkWiredInTyConName   UserSyntax gHC_TYPES (fsLit "Word")   wordTyConKey     wordTyCon
 wordDataConName    = mkWiredInDataConName UserSyntax gHC_TYPES (fsLit "W#")     wordDataConKey   wordDataCon
+word8TyConName     = mkWiredInTyConName   UserSyntax gHC_WORD  (fsLit "Word8")  word8TyConKey    word8TyCon
+word8DataConName   = mkWiredInDataConName UserSyntax gHC_WORD  (fsLit "W8#")    word8DataConKey  word8DataCon
+
+floatTyConName, floatDataConName, doubleTyConName, doubleDataConName :: Name
 floatTyConName     = mkWiredInTyConName   UserSyntax gHC_TYPES (fsLit "Float")  floatTyConKey    floatTyCon
 floatDataConName   = mkWiredInDataConName UserSyntax gHC_TYPES (fsLit "F#")     floatDataConKey  floatDataCon
 doubleTyConName    = mkWiredInTyConName   UserSyntax gHC_TYPES (fsLit "Double") doubleTyConKey   doubleTyCon
@@ -617,6 +625,16 @@ wordTyCon = pcNonRecDataTyCon wordTyConName
 wordDataCon :: DataCon
 wordDataCon = pcDataCon wordDataConName [] [wordPrimTy] wordTyCon
 
+word8Ty :: Type
+word8Ty = mkTyConTy word8TyCon
+
+word8TyCon :: TyCon
+word8TyCon = pcNonRecDataTyCon word8TyConName
+                      (Just (CType "" Nothing ("HsWord8", fsLit "HsWord8"))) []
+                      [word8DataCon]
+word8DataCon :: DataCon
+word8DataCon = pcDataCon word8DataConName [] [wordPrimTy] word8TyCon
+
 floatTy :: Type
 floatTy = mkTyConTy floatTyCon