Fix #8770

As usual, Mac OS X is extremely annoying (or the software is, anyway),
because not only does it load dynamic libraries with the .dylib
extension, but also the .so extension. For whatever reason. At least
it's easy to fix.

Signed-off-by: Austin Seipp <austin@well-typed.com>

2 files changed, 15 insertions, 6 deletions

diff --git a/compiler/ghci/Linker.lhs b/compiler/ghci/Linker.lhs
index eb3e226ab4..274f2fbd44 100644
--- a/compiler/ghci/Linker.lhs
+++ b/compiler/ghci/Linker.lhs
@@ -378,7 +378,16 @@ preloadLib dflags lib_paths framework_paths lib_spec
              -> do maybe_errstr <- loadDLL (mkSOName platform dll_unadorned)
                    case maybe_errstr of
                       Nothing -> maybePutStrLn dflags "done"
-                      Just mm -> preloadFailed mm lib_paths lib_spec
+                      Just mm | platformOS platform /= OSDarwin ->
+                        preloadFailed mm lib_paths lib_spec
+                      Just mm | otherwise -> do
+                        -- As a backup, on Darwin, try to also load a .so file
+                        -- since (apparently) some things install that way - see
+                        -- ticket #8770.
+                        err2 <- loadDLL $ ("lib" ++ dll_unadorned) <.> "so"
+                        case err2 of
+                          Nothing -> maybePutStrLn dflags "done"
+                          Just _  -> preloadFailed mm lib_paths lib_spec
 
           DLLPath dll_path
              -> do maybe_errstr <- loadDLL dll_path
diff --git a/compiler/main/DriverPhases.hs b/compiler/main/DriverPhases.hs
index 2de19b9795..c406f6ad0d 100644
--- a/compiler/main/DriverPhases.hs
+++ b/compiler/main/DriverPhases.hs
@@ -240,14 +240,14 @@ objish_suffixes :: Platform -> [String]
 -- Use the appropriate suffix for the system on which
 -- the GHC-compiled code will run
 objish_suffixes platform = case platformOS platform of
-                           OSMinGW32 -> [ "o", "O", "obj", "OBJ" ]
-                           _         -> [ "o" ]
+  OSMinGW32 -> [ "o", "O", "obj", "OBJ" ]
+  _         -> [ "o" ]
 
 dynlib_suffixes :: Platform -> [String]
 dynlib_suffixes platform = case platformOS platform of
-                           OSMinGW32 -> ["dll", "DLL"]
-                           OSDarwin  -> ["dylib"]
-                           _         -> ["so"]
+  OSMinGW32 -> ["dll", "DLL"]
+  OSDarwin  -> ["dylib", "so"]
+  _         -> ["so"]
 
 isHaskellishSuffix, isHaskellSrcSuffix, isCishSuffix, isExtCoreSuffix,
     isHaskellUserSrcSuffix