Provide a raw ByteString version of FilePath and environment APIs

The new module System.Posix.ByteString provides exactly the same API
as System.Posix, except that:

  - There is a new type: RawFilePath = ByteString

  - All functions mentioning FilePath in the System.Posix API
    use RawFilePath in the System.Posix.ByteString API

  - RawFilePaths are not subject to Unicode locale encoding and
    decoding, unlike FilePaths.  They are the exact bytes passed to and
    returned from the underlying POSIX API.

  - Similarly for functions that deal in environment
    strings (System.Posix.Env): these use untranslated ByteStrings
    in System.Posix.Environment

  - There is a new function

     System.Posix.ByteString.getArgs :: [ByteString]

    returning the raw untranslated arguments as passed to exec() when
    the program was started.

5 files changed, 240 insertions, 6 deletions

diff --git a/System/Posix/DynamicLinker/ByteString.hsc b/System/Posix/DynamicLinker/ByteString.hsc
new file mode 100644
index 0000000..6525eb9
--- /dev/null
+++ b/System/Posix/DynamicLinker/ByteString.hsc
@@ -0,0 +1,70 @@
+#if __GLASGOW_HASKELL__ >= 701
+{-# LANGUAGE Trustworthy #-}
+#endif
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  System.Posix.DynamicLinker.ByteString
+-- Copyright   :  (c) Volker Stolz <vs@foldr.org> 2003
+-- License     :  BSD-style (see the file libraries/base/LICENSE)
+-- 
+-- Maintainer  :  vs@foldr.org
+-- Stability   :  provisional
+-- Portability :  non-portable (requires POSIX)
+--
+-- Dynamic linker support through dlopen()
+-----------------------------------------------------------------------------
+
+module System.Posix.DynamicLinker.ByteString (
+
+    module System.Posix.DynamicLinker.Prim,
+    dlopen,
+    dlsym,
+    dlerror,
+    dlclose,
+    withDL, withDL_,
+    undl,
+    )
+
+--  Usage:
+--  ******
+--  
+--  Let's assume you want to open a local shared library \'foo\' (.\/libfoo.so)
+--  offering a function
+--    @char \* mogrify (char\*,int)@
+--  and invoke @str = mogrify("test",1)@:
+-- 
+--  
+--  type Fun = CString -> Int -> IO CString
+--  foreign import dynamic unsafe fun__ :: FunPtr Fun -> Fun
+-- 
+--  withDL "libfoo.so" [RTLD_NOW] \$ \\ mod -> do
+--     funptr <- dlsym mod "mogrify"
+--     let fun = fun__ funptr
+--     withCString "test" \$ \\ str -> do
+--       strptr <- fun str 1
+--       strstr <- peekCString strptr
+--       ...
+--  
+
+where
+
+import System.Posix.DynamicLinker.Common
+import System.Posix.DynamicLinker.Prim
+
+#include "HsUnix.h"
+
+import Control.Exception        ( bracket )
+import Control.Monad	( liftM )
+import Foreign
+import System.Posix.ByteString.FilePath
+
+dlopen :: RawFilePath -> [RTLDFlags] -> IO DL
+dlopen path flags = do
+  withFilePath path $ \ p -> do
+    liftM DLHandle $ throwDLErrorIf "dlopen" (== nullPtr) $ c_dlopen p (packRTLDFlags flags)
+
+withDL :: RawFilePath -> [RTLDFlags] -> (DL -> IO a) -> IO a
+withDL file flags f = bracket (dlopen file flags) (dlclose) f
+
+withDL_ :: RawFilePath -> [RTLDFlags] -> (DL -> IO a) -> IO ()
+withDL_ file flags f = withDL file flags f >> return ()
diff --git a/System/Posix/DynamicLinker/Common.hsc b/System/Posix/DynamicLinker/Common.hsc
new file mode 100644
index 0000000..2b5e0d9
--- /dev/null
+++ b/System/Posix/DynamicLinker/Common.hsc
@@ -0,0 +1,90 @@
+#if __GLASGOW_HASKELL__ >= 701
+{-# LANGUAGE Trustworthy #-}
+#endif
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  System.Posix.DynamicLinker.Common
+-- Copyright   :  (c) Volker Stolz <vs@foldr.org> 2003
+-- License     :  BSD-style (see the file libraries/base/LICENSE)
+-- 
+-- Maintainer  :  vs@foldr.org
+-- Stability   :  provisional
+-- Portability :  non-portable (requires POSIX)
+--
+-- Dynamic linker support through dlopen()
+-----------------------------------------------------------------------------
+
+module System.Posix.DynamicLinker.Common (
+
+    module System.Posix.DynamicLinker.Prim,
+    dlsym,
+    dlerror,
+    dlclose,
+    undl,
+    throwDLErrorIf,
+    Module(..)
+    )
+
+--  Usage:
+--  ******
+--  
+--  Let's assume you want to open a local shared library \'foo\' (.\/libfoo.so)
+--  offering a function
+--    @char \* mogrify (char\*,int)@
+--  and invoke @str = mogrify("test",1)@:
+-- 
+--  
+--  type Fun = CString -> Int -> IO CString
+--  foreign import dynamic unsafe fun__ :: FunPtr Fun -> Fun
+-- 
+--  withDL "libfoo.so" [RTLD_NOW] \$ \\ mod -> do
+--     funptr <- dlsym mod "mogrify"
+--     let fun = fun__ funptr
+--     withCString "test" \$ \\ str -> do
+--       strptr <- fun str 1
+--       strstr <- peekCString strptr
+--       ...
+--  
+
+where
+
+#include "HsUnix.h"
+
+import System.Posix.DynamicLinker.Prim
+import Foreign
+import Foreign.C
+
+dlclose :: DL -> IO ()
+dlclose (DLHandle h) = throwDLErrorIf_ "dlclose" (/= 0) $ c_dlclose h
+dlclose h = error $ "dlclose: invalid argument" ++ (show h)
+
+dlerror :: IO String
+dlerror = c_dlerror >>= peekCString 
+
+-- |'dlsym' returns the address binding of the symbol described in @symbol@,
+-- as it occurs in the shared object identified by @source@.
+
+dlsym :: DL -> String -> IO (FunPtr a)
+dlsym source symbol = do
+  withCAString symbol $ \ s -> do
+    throwDLErrorIf "dlsym" (== nullFunPtr) $ c_dlsym (packDL source) s
+
+-- |'undl' obtains the raw handle. You mustn't do something like
+-- @withDL mod flags $ liftM undl >>= \ p -> use p@
+
+undl :: DL -> Ptr ()
+undl = packDL
+
+throwDLErrorIf :: String -> (a -> Bool) -> IO a -> IO a
+throwDLErrorIf s p f = do
+  r <- f
+  if (p r)
+    then dlerror >>= \ err -> ioError (userError ( s ++ ": " ++ err))
+    else return r
+
+throwDLErrorIf_ :: String -> (a -> Bool) -> IO a -> IO ()
+throwDLErrorIf_ s p f = throwDLErrorIf s p f >> return ()
+
+-- abstract handle for dynamically loaded module (EXPORTED)
+--
+newtype Module = Module (Ptr ())
diff --git a/System/Posix/DynamicLinker/Module.hsc b/System/Posix/DynamicLinker/Module.hsc
index c678fed..2e5d6fe 100644
--- a/System/Posix/DynamicLinker/Module.hsc
+++ b/System/Posix/DynamicLinker/Module.hsc
@@ -60,7 +60,8 @@ where
 #include "HsUnix.h"
 
 import System.Posix.DynamicLinker
-import Foreign.Ptr	( Ptr, nullPtr, FunPtr )
+import System.Posix.DynamicLinker.Common
+import Foreign.Ptr      ( Ptr, nullPtr, FunPtr )
 #if __GLASGOW_HASKELL__ > 611
 import System.Posix.Internals ( withFilePath )
 #else
@@ -70,10 +71,6 @@ withFilePath :: FilePath -> (CString -> IO a) -> IO a
 withFilePath = withCString
 #endif
 
--- abstract handle for dynamically loaded module (EXPORTED)
---
-newtype Module = Module (Ptr ())
-
 unModule              :: Module -> (Ptr ())
 unModule (Module adr)  = adr
 
diff --git a/System/Posix/DynamicLinker/Module/ByteString.hsc b/System/Posix/DynamicLinker/Module/ByteString.hsc
new file mode 100644
index 0000000..59f45e2
--- /dev/null
+++ b/System/Posix/DynamicLinker/Module/ByteString.hsc
@@ -0,0 +1,77 @@
+{-# LANGUAGE ForeignFunctionInterface #-}
+#if __GLASGOW_HASKELL__ >= 701
+{-# LANGUAGE Trustworthy #-}
+#endif
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  System.Posix.DynamicLinker.Module.ByteString
+-- Copyright   :  (c) Volker Stolz <vs@foldr.org> 2003
+-- License     :  BSD-style (see the file libraries/base/LICENSE)
+-- 
+-- Maintainer  :  vs@foldr.org
+-- Stability   :  provisional
+-- Portability :  non-portable (requires POSIX)
+--
+-- DLOpen support, old API
+--  Derived from GModule.chs by M.Weber & M.Chakravarty which is part of c2hs
+--  I left the API more or less the same, mostly the flags are different.
+--
+-----------------------------------------------------------------------------
+
+module System.Posix.DynamicLinker.Module.ByteString (
+
+--  Usage:
+--  ******
+--  
+--  Let's assume you want to open a local shared library 'foo' (./libfoo.so)
+--  offering a function
+--    char * mogrify (char*,int)
+--  and invoke str = mogrify("test",1):
+-- 
+--  type Fun = CString -> Int -> IO CString
+--  foreign import dynamic unsafe fun__ :: FunPtr Fun -> Fun
+-- 
+--  withModule (Just ".") ("libfoo.so") [RTLD_NOW] $ \ mod -> do
+--     funptr <- moduleSymbol mod "mogrify"
+--     let fun = fun__ funptr
+--     withCString "test" $ \ str -> do
+--       strptr <- fun str 1
+--       strstr <- peekCString strptr
+--       ...
+
+      Module
+    , moduleOpen             -- :: String -> ModuleFlags -> IO Module
+    , moduleSymbol           -- :: Source -> String -> IO (FunPtr a)
+    , moduleClose            -- :: Module -> IO Bool
+    , moduleError            -- :: IO String
+    , withModule             -- :: Maybe String 
+                             -- -> String 
+	                     -- -> [ModuleFlags ]
+			     -- -> (Module -> IO a) 
+			     -- -> IO a
+    , withModule_            -- :: Maybe String 
+ 			     -- -> String 
+ 			     -- -> [ModuleFlags] 
+ 			     -- -> (Module -> IO a) 
+ 			     -- -> IO ()
+    )
+where
+
+#include "HsUnix.h"
+
+import System.Posix.DynamicLinker.Module hiding (moduleOpen)
+import System.Posix.DynamicLinker.Prim
+import System.Posix.DynamicLinker.Common
+
+import Foreign
+import System.Posix.ByteString.FilePath
+
+-- Opens a module (EXPORTED)
+--
+
+moduleOpen :: RawFilePath -> [RTLDFlags] -> IO Module
+moduleOpen file flags = do
+  modPtr <- withFilePath file $ \ modAddr -> c_dlopen modAddr (packRTLDFlags flags)
+  if (modPtr == nullPtr)
+      then moduleError >>= \ err -> ioError (userError ("dlopen: " ++ err))
+      else return $ Module modPtr
diff --git a/System/Posix/DynamicLinker/Prim.hsc b/System/Posix/DynamicLinker/Prim.hsc
index 2e5409e..9a21d77 100644
--- a/System/Posix/DynamicLinker/Prim.hsc
+++ b/System/Posix/DynamicLinker/Prim.hsc
@@ -30,7 +30,7 @@ module System.Posix.DynamicLinker.Prim (
   packRTLDFlags,
   RTLDFlags(..),
   packDL,
-  DL(..)
+  DL(..),
  )
 
 where