Use CPP to ensure compilation on GHC 7.0.x

Foreign.Unsafe was only introduced in later GHC versions and made mandatory
after GHC 7.6.

Blaze/ByteString/Builder/ByteString.hs

@@ -37,8 +37,13 @@ module Blaze.ByteString.Builder.ByteString
 import           Blaze.ByteString.Builder.Internal hiding (insertByteString)
 import qualified Blaze.ByteString.Builder.Internal as I   (insertByteString)
 
+#ifdef HAS_FOREIGN_UNSAFE_MODULE
 import Foreign                   (withForeignPtr, touchForeignPtr, copyBytes, plusPtr, minusPtr)
 import Foreign.ForeignPtr.Unsafe (unsafeForeignPtrToPtr)
+#else
+import Foreign                   (unsafeForeignPtrToPtr, withForeignPtr, touchForeignPtr, copyBytes, plusPtr, minusPtr)
+#endif
+
 import Data.Monoid
 
 import qualified Data.ByteString      as S
@@ -48,7 +53,8 @@ import qualified Data.ByteString.Lazy as L
 import qualified Data.ByteString.Base as S
 import qualified Data.ByteString.Lazy.Base as L -- FIXME: check if this is the right module
 #else
-import qualified Data.ByteString.Internal as S
+import qualified Data.ByteString.Internal      as S
+import qualified Data.ByteString.Lazy.Internal as L
 #endif
 
 

Blaze/ByteString/Builder/Internal.hs

@@ -49,8 +49,12 @@ module Blaze.ByteString.Builder.Internal (
   , defaultMaximalCopySize
 ) where
 
+#ifdef HAS_FOREIGN_UNSAFE_MODULE
 import Foreign                   (withForeignPtr, sizeOf, copyBytes, plusPtr, minusPtr)
 import Foreign.ForeignPtr.Unsafe (unsafeForeignPtrToPtr)
+#else
+import Foreign                   (unsafeForeignPtrToPtr, withForeignPtr, sizeOf, copyBytes, plusPtr, minusPtr)
+#endif
 
 import Control.Monad (unless)
 

Blaze/ByteString/Builder/Internal/Buffer.hs

@@ -40,9 +40,12 @@ module Blaze.ByteString.Builder.Internal.Buffer (
   , runPut
   ) where
 
-import Prelude
+#ifdef HAS_FOREIGN_UNSAFE_MODULE
 import Foreign                   (Word8, ForeignPtr, Ptr, plusPtr, minusPtr)
 import Foreign.ForeignPtr.Unsafe (unsafeForeignPtrToPtr)
+#else
+import Foreign                   (unsafeForeignPtrToPtr, Word8, ForeignPtr, Ptr, plusPtr, minusPtr)
+#endif
 
 import qualified Data.ByteString      as S
 

blaze-builder.cabal

@@ -49,6 +49,11 @@ Source-repository head
 Library
   ghc-options:       -Wall
 
+  -- Earlier versions of GHC did not split off unsafe functions in "Foreign"
+  if impl(ghc >= 7.4)
+      cpp-options:   -DHAS_FOREIGN_UNSAFE_MODULE
+
+
   exposed-modules:   Blaze.ByteString.Builder
                      Blaze.ByteString.Builder.Int
                      Blaze.ByteString.Builder.Word