Cleanup String/FastString conversions

Remove unused mkPtrString and isUnderscoreFS.
We no longer use mkPtrString since 1d03d8bef96.

Remove unnecessary conversions between FastString and String and back.

1 files changed, 2 insertions, 32 deletions

diff --git a/compiler/GHC/Data/FastString.hs b/compiler/GHC/Data/FastString.hs
index 483d40cca1..98814fa6b3 100644
--- a/compiler/GHC/Data/FastString.hs
+++ b/compiler/GHC/Data/FastString.hs
@@ -30,8 +30,8 @@
 --   * Pointer and size of a Latin-1 encoded string.
 --   * Practically no operations.
 --   * Outputting them is fast.
---   * Generated by 'mkPtrString'.
---   * Length of string literals (mkPtrString "abc") is computed statically
+--   * Generated by 'mkPtrString#'.
+--   * Length of string literals (mkPtrString# "abc"#) is computed statically
 --   * Turn into 'GHC.Utils.Outputable.SDoc' with 'GHC.Utils.Outputable.ptext'
 --   * Requires manual memory management.
 --     Improper use may lead to memory leaks or dangling pointers.
@@ -85,7 +85,6 @@ module GHC.Data.FastString
         concatFS,
         consFS,
         nilFS,
-        isUnderscoreFS,
         lexicalCompareFS,
         uniqCompareFS,
 
@@ -101,7 +100,6 @@ module GHC.Data.FastString
 
         -- ** Construction
         mkPtrString#,
-        mkPtrString,
 
         -- ** Deconstruction
         unpackPtrString,
@@ -134,7 +132,6 @@ import Foreign.C
 import System.IO
 import Data.Data
 import Data.IORef
-import Data.Char
 import Data.Semigroup as Semi
 
 import Foreign
@@ -623,9 +620,6 @@ uniqueOfFS fs = uniq fs
 nilFS :: FastString
 nilFS = mkFastString ""
 
-isUnderscoreFS :: FastString -> Bool
-isUnderscoreFS fs = fs == fsLit "_"
-
 -- -----------------------------------------------------------------------------
 -- Stats
 
@@ -667,30 +661,6 @@ mkPtrString# :: Addr# -> PtrString
 {-# INLINE mkPtrString# #-}
 mkPtrString# a# = PtrString (Ptr a#) (ptrStrLength (Ptr a#))
 
--- | Encode a 'String' into a newly allocated 'PtrString' using Latin-1
--- encoding.  The original string must not contain non-Latin-1 characters
--- (above codepoint @0xff@).
-{-# NOINLINE[0] mkPtrString #-} -- see rules below
-mkPtrString :: String -> PtrString
-mkPtrString s =
- -- we don't use `unsafeDupablePerformIO` here to avoid potential memory leaks
- -- and because someone might be using `eqAddr#` to check for string equality.
- unsafePerformIO (do
-   let len = length s
-   p <- mallocBytes len
-   let
-     loop :: Int -> String -> IO ()
-     loop !_ []    = return ()
-     loop n (c:cs) = do
-        pokeByteOff p n (fromIntegral (ord c) :: Word8)
-        loop (1+n) cs
-   loop 0 s
-   return (PtrString p len)
- )
-
-{-# RULES "mkPtrString"
-    forall x . mkPtrString (unpackCString# x) = mkPtrString#  x #-}
-
 -- | Decode a 'PtrString' back into a 'String' using Latin-1 encoding.
 -- This does not free the memory associated with 'PtrString'.
 unpackPtrString :: PtrString -> String