Don't use FastString to convert string to UTF8

4 files changed, 23 insertions, 25 deletions

diff --git a/compiler/GHC/Data/StringBuffer.hs b/compiler/GHC/Data/StringBuffer.hs
index 891598d683..1f01451971 100644
--- a/compiler/GHC/Data/StringBuffer.hs
+++ b/compiler/GHC/Data/StringBuffer.hs
@@ -191,7 +191,7 @@ stringToStringBuffer str =
   let size = utf8EncodedLength str
   buf <- mallocForeignPtrArray (size+3)
   unsafeWithForeignPtr buf $ \ptr -> do
-    utf8EncodeString ptr str
+    utf8EncodeStringPtr ptr str
     pokeArray (ptr `plusPtr` size :: Ptr Word8) [0,0,0]
     -- sentinels for UTF-8 decoding
   return (StringBuffer buf size 0)
diff --git a/compiler/GHC/Hs/Doc.hs b/compiler/GHC/Hs/Doc.hs
index 400df5cdf9..207b65f2fd 100644
--- a/compiler/GHC/Hs/Doc.hs
+++ b/compiler/GHC/Hs/Doc.hs
@@ -27,7 +27,6 @@ import GHC.Prelude
 
 import GHC.Utils.Binary
 import GHC.Utils.Encoding
-import GHC.Utils.IO.Unsafe
 import GHC.Types.Name
 import GHC.Utils.Outputable as Outputable
 import GHC.Types.SrcLoc
@@ -35,12 +34,10 @@ import GHC.Types.SrcLoc
 import Data.ByteString (ByteString)
 import qualified Data.ByteString as BS
 import qualified Data.ByteString.Char8 as C8
-import qualified Data.ByteString.Internal as BS
 import Data.Data
 import Data.Map (Map)
 import qualified Data.Map as Map
 import Data.Maybe
-import Foreign
 
 -- | Haskell Documentation String
 --
@@ -68,13 +65,7 @@ isEmptyDocString :: HsDocString -> Bool
 isEmptyDocString (HsDocString bs) = BS.null bs
 
 mkHsDocString :: String -> HsDocString
-mkHsDocString s =
-  inlinePerformIO $ do
-    let len = utf8EncodedLength s
-    buf <- mallocForeignPtrBytes len
-    withForeignPtr buf $ \ptr -> do
-      utf8EncodeString ptr s
-      pure (HsDocString (BS.fromForeignPtr buf 0 len))
+mkHsDocString s = HsDocString (utf8EncodeString s)
 
 -- | Create a 'HsDocString' from a UTF8-encoded 'ByteString'.
 mkHsDocStringUtf8ByteString :: ByteString -> HsDocString
diff --git a/compiler/GHC/StgToCmm/Prof.hs b/compiler/GHC/StgToCmm/Prof.hs
index 451d38ec4c..0176c3dbdc 100644
--- a/compiler/GHC/StgToCmm/Prof.hs
+++ b/compiler/GHC/StgToCmm/Prof.hs
@@ -51,6 +51,7 @@ import GHC.Utils.Outputable
 import GHC.Utils.Panic
 import GHC.Driver.CodeOutput ( ipInitCode )
 
+import GHC.Utils.Encoding
 
 import Control.Monad
 import Data.Char (ord)
@@ -230,9 +231,8 @@ emitCostCentreDecl cc = do
   ; modl  <- newByteStringCLit (bytesFS $ moduleNameFS
                                         $ moduleName
                                         $ cc_mod cc)
-  ; loc <- newByteStringCLit $ bytesFS $ mkFastString $
+  ; loc <- newByteStringCLit $ utf8EncodeString $
                    showPpr dflags (costCentreSrcSpan cc)
-           -- XXX going via FastString to get UTF-8 encoding is silly
   ; let
      lits = [ zero platform,  -- StgInt ccID,
               label,          -- char *label,
@@ -296,20 +296,17 @@ emitInfoTableProv ip = do
   ; let mod = infoProvModule ip
   ; let (src, label) = maybe ("", "") (\(s, l) -> (showPpr dflags s, l)) (infoTableProv ip)
   ; platform <- getPlatform
-                        -- NB. bytesFS: we want the UTF-8 bytes here (#5559)
-  ; label <- newByteStringCLit (bytesFS $ mkFastString label)
+  ; let mk_string = newByteStringCLit . utf8EncodeString
+  ; label <- mk_string label
   ; modl  <- newByteStringCLit (bytesFS $ moduleNameFS
                                         $ moduleName
                                         $ mod)
 
-  ; ty_string  <- newByteStringCLit (bytesFS (mkFastString (infoTableType ip)))
-  ; loc <- newByteStringCLit $ bytesFS $ mkFastString $ src
-           -- XXX going via FastString to get UTF-8 encoding is silly
-  ; table_name <- newByteStringCLit $ bytesFS $ mkFastString $
-                    showPpr dflags (pprCLabel platform CStyle (infoTablePtr ip))
-
-  ; closure_type <- newByteStringCLit $ bytesFS $ mkFastString $
-                    showPpr dflags (text $ show $ infoProvEntClosureType ip)
+  ; ty_string  <- mk_string (infoTableType ip)
+  ; loc <- mk_string src
+  ; table_name <- mk_string (showPpr dflags (pprCLabel platform CStyle (infoTablePtr ip)))
+  ; closure_type <- mk_string
+                      (showPpr dflags (text $ show $ infoProvEntClosureType ip))
   ; let
      lits = [ CmmLabel (infoTablePtr ip), -- Info table pointer
               table_name,     -- char *table_name
diff --git a/libraries/ghc-boot/GHC/Utils/Encoding.hs b/libraries/ghc-boot/GHC/Utils/Encoding.hs
index 519b607425..ba07784b0d 100644
--- a/libraries/ghc-boot/GHC/Utils/Encoding.hs
+++ b/libraries/ghc-boot/GHC/Utils/Encoding.hs
@@ -27,6 +27,7 @@ module GHC.Utils.Encoding (
         utf8DecodeStringLazy,
         utf8EncodeChar,
         utf8EncodeString,
+        utf8EncodeStringPtr,
         utf8EncodeShortByteString,
         utf8EncodedLength,
         countUTF8Chars,
@@ -276,8 +277,17 @@ utf8EncodeChar write# c =
 #endif
         s -> (# s, () #)
 
-utf8EncodeString :: Ptr Word8 -> String -> IO ()
-utf8EncodeString (Ptr a#) str = go a# str
+utf8EncodeString :: String -> ByteString
+utf8EncodeString s =
+  unsafePerformIO $ do
+    let len = utf8EncodedLength s
+    buf <- mallocForeignPtrBytes len
+    withForeignPtr buf $ \ptr -> do
+      utf8EncodeStringPtr ptr s
+      pure (BS.fromForeignPtr buf 0 len)
+
+utf8EncodeStringPtr :: Ptr Word8 -> String -> IO ()
+utf8EncodeStringPtr (Ptr a#) str = go a# str
   where go !_   []   = return ()
         go a# (c:cs) = do
 #if !MIN_VERSION_base(4,16,0)