From 23ef9f3d13b6158842106da4b84a888f0cb3342e Mon Sep 17 00:00:00 2001
From: Bodigrim <andrew.lelechenko@gmail.com>
Date: Sun, 12 Sep 2021 00:35:19 +0100
Subject: [PATCH] Fix detection of endianness in test suite (#419)

* Fix detection of endianness in test suite (#421)

* Work around when getFileSystemEncoding is ASCII (#421)
---
 bytestring.cabal                                  |  2 --
 tests/Properties/ByteString.hs                    | 15 +++++++++++----
 .../Data/ByteString/Builder/Prim/TestUtils.hs     | 14 ++++++++++----
 3 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/bytestring.cabal b/bytestring.cabal
index 7f3c782db..909c154b9 100644
--- a/bytestring.cabal
+++ b/bytestring.cabal
@@ -160,8 +160,6 @@ test-suite test-builder
                     tasty,
                     tasty-hunit,
                     tasty-quickcheck
-  if impl(ghc < 8.4)
-    build-depends:  ghc-byteorder
   ghc-options:      -Wall -fwarn-tabs -threaded -rtsopts
   default-language: Haskell2010
 
diff --git a/tests/Properties/ByteString.hs b/tests/Properties/ByteString.hs
index c014cb02a..7461d502b 100644
--- a/tests/Properties/ByteString.hs
+++ b/tests/Properties/ByteString.hs
@@ -23,6 +23,7 @@
 #ifndef BYTESTRING_LAZY
 module Properties.ByteString (tests) where
 import qualified Data.ByteString as B
+import GHC.IO.Encoding
 #else
 module Properties.ByteStringLazy (tests) where
 import qualified Data.ByteString.Lazy as B
@@ -83,10 +84,16 @@ tests =
     \x -> ioProperty $ do
       r <- B.toFilePath x >>= B.fromFilePath
       pure (r === x)
-  , testProperty "fromFilePath >>= toFilePath" $
-    \x -> ioProperty $ do
-      r <- B.fromFilePath x >>= B.toFilePath
-      pure (r === x)
+  , testProperty "fromFilePath >>= toFilePath" $ ioProperty $ do
+    let prop x = ioProperty $ do
+          r <- B.fromFilePath x >>= B.toFilePath
+          pure (r === x)
+    -- Normally getFileSystemEncoding returns a Unicode encoding,
+    -- but if it is ASCII, we should not generate Unicode filenames.
+    enc <- getFileSystemEncoding
+    pure $ case textEncodingName enc of
+      "ASCII" -> property (prop . getASCIIString)
+      _       -> property prop
 #endif
 #endif
 
diff --git a/tests/builder/Data/ByteString/Builder/Prim/TestUtils.hs b/tests/builder/Data/ByteString/Builder/Prim/TestUtils.hs
index 2a72b4a64..94ac1ac65 100644
--- a/tests/builder/Data/ByteString/Builder/Prim/TestUtils.hs
+++ b/tests/builder/Data/ByteString/Builder/Prim/TestUtils.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 -- |
 -- Copyright   : (c) 2011 Simon Meier
@@ -78,13 +79,14 @@ import           Data.Int
 import           Data.Word
 import           Foreign (Storable(..), castPtr, minusPtr, with)
 import           Numeric (showHex)
-import           GHC.ByteOrder
 import           System.IO.Unsafe (unsafePerformIO)
 
 import           Test.Tasty
 import           Test.Tasty.HUnit (assertBool, testCase)
 import           Test.Tasty.QuickCheck (Arbitrary(..), testProperty)
 
+#include <ghcautoconf.h>
+
 -- Helper functions
 -------------------
 
@@ -332,10 +334,14 @@ littleEndian_list :: (Storable a, Bits a, Integral a) => a -> [Word8]
 littleEndian_list x =
     map (fromIntegral . (x `shiftR`) . (8*)) $ [0..sizeOf x - 1]
 
+-- See https://gitlab.haskell.org/ghc/ghc/-/issues/20338
+-- and https://gitlab.haskell.org/ghc/ghc/-/issues/18445
 hostEndian_list :: (Storable a, Bits a, Integral a) => a -> [Word8]
-hostEndian_list = case targetByteOrder of
-    LittleEndian -> littleEndian_list
-    BigEndian    -> bigEndian_list
+#if defined(WORDS_BIGENDIAN)
+hostEndian_list = bigEndian_list
+#else
+hostEndian_list = littleEndian_list
+#endif
 
 float_list :: (Word32 -> [Word8]) -> Float -> [Word8]
 float_list f  = f . coerceFloatToWord32