Reorganisation of the source tree

[ghc-hetmet.git] / compiler / ghci / ObjLink.lhs

diff --git a/compiler/ghci/ObjLink.lhs b/compiler/ghci/ObjLink.lhs
new file mode 100644 (file)
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+%
+% (c) The University of Glasgow, 2000
+%
+
+-- ---------------------------------------------------------------------------
+--     The dynamic linker for object code (.o .so .dll files)
+-- ---------------------------------------------------------------------------
+
+Primarily, this module consists of an interface to the C-land dynamic linker.
+
+\begin{code}
+{-# OPTIONS -#include "Linker.h" #-}
+
+module ObjLink ( 
+   initObjLinker,       -- :: IO ()
+   loadDLL,             -- :: String -> IO (Maybe String)
+   loadObj,             -- :: String -> IO ()
+   unloadObj,           -- :: String -> IO ()
+   lookupSymbol,        -- :: String -> IO (Maybe (Ptr a))
+   resolveObjs          -- :: IO SuccessFlag
+  )  where
+
+import Monad            ( when )
+
+import Foreign.C
+import Foreign         ( Ptr, nullPtr )
+import Panic           ( panic )
+import BasicTypes      ( SuccessFlag, successIf )
+import Config          ( cLeadingUnderscore )
+import Outputable
+
+-- ---------------------------------------------------------------------------
+-- RTS Linker Interface
+-- ---------------------------------------------------------------------------
+
+lookupSymbol :: String -> IO (Maybe (Ptr a))
+lookupSymbol str_in = do
+   let str = prefixUnderscore str_in
+   withCString str $ \c_str -> do
+     addr <- c_lookupSymbol c_str
+     if addr == nullPtr
+       then return Nothing
+       else return (Just addr)
+
+prefixUnderscore :: String -> String
+prefixUnderscore
+ | cLeadingUnderscore == "YES" = ('_':)
+ | otherwise                   = id
+
+loadDLL :: String -> IO (Maybe String)
+-- Nothing      => success
+-- Just err_msg => failure
+loadDLL str = do
+  maybe_errmsg <- withCString str $ \dll -> c_addDLL dll
+  if maybe_errmsg == nullPtr
+       then return Nothing
+       else do str <- peekCString maybe_errmsg
+               return (Just str)
+
+loadObj :: String -> IO ()
+loadObj str = do
+   withCString str $ \c_str -> do
+     r <- c_loadObj c_str
+     when (r == 0) (panic "loadObj: failed")
+
+unloadObj :: String -> IO ()
+unloadObj str =
+   withCString str $ \c_str -> do
+     r <- c_unloadObj c_str
+     when (r == 0) (panic "unloadObj: failed")
+
+resolveObjs :: IO SuccessFlag
+resolveObjs = do
+   r <- c_resolveObjs
+   return (successIf (r /= 0))
+
+-- ---------------------------------------------------------------------------
+-- Foreign declaractions to RTS entry points which does the real work;
+-- ---------------------------------------------------------------------------
+
+#if __GLASGOW_HASKELL__ >= 504
+foreign import ccall unsafe "addDLL"      c_addDLL :: CString -> IO CString
+foreign import ccall unsafe "initLinker"   initObjLinker :: IO ()
+foreign import ccall unsafe "lookupSymbol" c_lookupSymbol :: CString -> IO (Ptr a)
+foreign import ccall unsafe "loadObj"      c_loadObj :: CString -> IO Int
+foreign import ccall unsafe "unloadObj"    c_unloadObj :: CString -> IO Int
+foreign import ccall unsafe "resolveObjs"  c_resolveObjs :: IO Int
+#else
+foreign import "addDLL"       unsafe   c_addDLL :: CString -> IO CString
+foreign import "initLinker"   unsafe   initLinker :: IO ()
+foreign import "lookupSymbol" unsafe   c_lookupSymbol :: CString -> IO (Ptr a)
+foreign import "loadObj"      unsafe   c_loadObj :: CString -> IO Int
+foreign import "unloadObj"    unsafe   c_unloadObj :: CString -> IO Int
+foreign import "resolveObjs"  unsafe   c_resolveObjs :: IO Int
+#endif
+
+\end{code}