Reorganisation of the source tree

Most of the other users of the fptools build system have migrated to
Cabal, and with the move to darcs we can now flatten the source tree
without losing history, so here goes.

The main change is that the ghc/ subdir is gone, and most of what it
contained is now at the top level.  The build system now makes no
pretense at being multi-project, it is just the GHC build system.

No doubt this will break many things, and there will be a period of
instability while we fix the dependencies.  A straightforward build
should work, but I haven't yet fixed binary/source distributions.
Changes to the Building Guide will follow, too.

1 files changed, 97 insertions, 0 deletions

diff --git a/compiler/ghci/ObjLink.lhs b/compiler/ghci/ObjLink.lhs
new file mode 100644
index 0000000000..057938a45e
--- /dev/null
+++ b/compiler/ghci/ObjLink.lhs
@@ -0,0 +1,97 @@
+%
+% (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}