Support SCC pragmas

Fixes #202.

CHANGES.md

@@ -6,6 +6,8 @@ Version 1.17 [????.??.??]
 * Support GHC 9.10.
 * Add support namespace identifiers in fixity declarations. As part of these
   changes, the `DInfixD` data constructor now has a `NamespaceSpecifier` field.
+* Add support for `SCC` declarations via the new `DSCCP` data constructor for
+  the `DPragma` data type.
 * `extractBoundNamesDPat` no longer extracts type variables from constructor
   patterns. That this function ever did extract type variables was a mistake,
   and the new behavior of `extractBoundNamesDPat` brings it in line with the

Language/Haskell/TH/Desugar/AST.hs

@@ -297,6 +297,7 @@ data DPragma = DInlineP Name Inline RuleMatch Phases
              | DLineP Int String
              | DCompleteP [Name] (Maybe Name)
              | DOpaqueP Name
+             | DSCCP Name (Maybe String)
              deriving (Eq, Show, Data, Generic, Lift)
 
 -- | Corresponds to TH's @RuleBndr@ type.

Language/Haskell/TH/Desugar/Core.hs

@@ -1065,6 +1065,9 @@ dsPragma (CompleteP cls mty)             = return $ DCompleteP cls mty
 #if __GLASGOW_HASKELL__ >= 903
 dsPragma (OpaqueP n)                     = return $ DOpaqueP n
 #endif
+#if __GLASGOW_HASKELL__ >= 909
+dsPragma (SCCP nm mstr)                  = return $ DSCCP nm mstr
+#endif
 
 -- | Desugar a @RuleBndr@.
 dsRuleBndr :: DsMonad q => RuleBndr -> q DRuleBndr

Language/Haskell/TH/Desugar/Sweeten.hs

@@ -279,6 +279,11 @@ pragmaToTH (DOpaqueP n) = OpaqueP n
 #else
 pragmaToTH (DOpaqueP {}) = error "OPAQUE pragmas only supported in GHC 9.4+"
 #endif
+#if __GLASGOW_HASKELL__ >= 909
+pragmaToTH (DSCCP nm mstr) = SCCP nm mstr
+#else
+pragmaToTH (DSCCP {}) = error "SCCP pragmas only supported in GHC 9.10+"
+#endif
 
 ruleBndrToTH :: DRuleBndr -> RuleBndr
 ruleBndrToTH (DRuleVar n) = RuleVar n

Test/Dec.hs

@@ -56,6 +56,7 @@ $(S.dectest19)
 
 #if __GLASGOW_HASKELL__ >= 909
 $(S.dectest20)
+$(S.dectest21)
 #endif
 
 $(fmap unqualify S.instance_test)

Test/DsDec.hs

@@ -81,6 +81,7 @@ $(dsDecSplice S.dectest19)
 
 #if __GLASGOW_HASKELL__ >= 909
 $(dsDecSplice S.dectest20)
+$(dsDecSplice S.dectest21)
 #endif
 
 $(do decs <- S.rec_sel_test

Test/Splices.hs

@@ -553,6 +553,10 @@ dectest20 = [d| infixr 3 data !@#
                 (!@#) = (&&)
 
                 type family (!@#) :: Bool -> Bool -> Bool |]
+
+dectest21 = [d| {-# SCC dec21 "dec21" #-}
+                dec21 :: a -> a
+                dec21 x = x |]
 #endif
 
 instance_test = [d| instance (Show a, Show b) => Show (a -> b) where