MERGE: Fix Windows DEP violations (bug #885)

Original patch by brianlsmith@gmail.com

compiler/ghci/ByteCodeFFI.lhs

@@ -5,7 +5,7 @@
 ByteCodeGen: Generate machine-code sequences for foreign import
 
 \begin{code}
-module ByteCodeFFI ( mkMarshalCode, moan64 ) where
+module ByteCodeFFI ( mkMarshalCode, moan64, newExec ) where
 
 #include "HsVersions.h"
 
@@ -18,10 +18,12 @@ import Panic
 -- there is ifdeffery below
 import Control.Exception ( throwDyn )
 import Data.Bits	( Bits(..), shiftR, shiftL )
-import Foreign		( newArray, Ptr )
 import Data.List        ( mapAccumL )
 
 import Data.Word	( Word8, Word32 )
+import Foreign		( Ptr, FunPtr, castPtrToFunPtr,
+			  Storable, sizeOf, pokeArray )
+import Foreign.C	( CUInt )
 import System.IO.Unsafe ( unsafePerformIO )
 import System.IO	( hPutStrLn, stderr )
 -- import Debug.Trace	( trace )
@@ -70,14 +72,23 @@ we don't clear our own (single) arg off the C stack.
 -}
 mkMarshalCode :: CCallConv
               -> (Int, CgRep) -> Int -> [(Int, CgRep)] 
-              -> IO (Ptr Word8)
+              -> IO (FunPtr ())
 mkMarshalCode cconv (r_offW, r_rep) addr_offW arg_offs_n_reps
    = let bytes = mkMarshalCode_wrk cconv (r_offW, r_rep) 
                                    addr_offW arg_offs_n_reps
-     in  Foreign.newArray bytes
-
+     in  newExec bytes
 
+newExec :: Storable a => [a] -> IO (FunPtr ())
+newExec code
+   = do ptr <- _allocateExec (fromIntegral $ codeSize undefined code)
+        pokeArray ptr code
+        return (castPtrToFunPtr ptr)
+   where
+   codeSize :: Storable a => a -> [a] -> Int
+   codeSize dummy array = sizeOf(dummy) * length array
 
+foreign import ccall unsafe "allocateExec"
+  _allocateExec :: CUInt -> IO (Ptr a)  
 
 mkMarshalCode_wrk :: CCallConv 
                   -> (Int, CgRep) -> Int -> [(Int, CgRep)] 

compiler/ghci/ByteCodeGen.lhs

@@ -10,6 +10,7 @@ module ByteCodeGen ( UnlinkedBCO, byteCodeGen, coreExprToBCOs ) where
 #include "HsVersions.h"
 
 import ByteCodeInstr
+import ByteCodeItbls
 import ByteCodeFFI
 import ByteCodeAsm
 import ByteCodeLink
@@ -48,7 +49,7 @@ import Constants
 
 import Data.List	( intersperse, sortBy, zip4, zip6, partition )
 import Foreign		( Ptr, castPtr, mallocBytes, pokeByteOff, Word8,
-			  withForeignPtr )
+			  withForeignPtr, castFunPtrToPtr )
 import Foreign.C	( CInt )
 import Control.Exception	( throwDyn )
 
@@ -138,7 +139,7 @@ mkProtoBCO
    -> Int
    -> [StgWord]
    -> Bool   	-- True <=> is a return point, rather than a function
-   -> [Ptr ()]
+   -> [BcPtr]
    -> ProtoBCO name
 mkProtoBCO nm instrs_ordlist origin arity bitmap_size bitmap
   is_ret mallocd_blocks
@@ -926,7 +927,7 @@ generateCCall d0 s p ccall_spec@(CCallSpec target cconv safety) fn args_r_to_l
          ioToBc (mkMarshalCode cconv
                     (r_offW, r_rep) addr_offW
                     (zip args_offW a_reps))	`thenBc` \ addr_of_marshaller ->
-         recordMallocBc addr_of_marshaller	`thenBc_`
+         recordItblMallocBc (ItblPtr (castFunPtrToPtr addr_of_marshaller)) `thenBc_`
      let
 	 -- Offset of the next stack frame down the stack.  The CCALL
  	 -- instruction needs to describe the chunk of stack containing
@@ -935,7 +936,7 @@ generateCCall d0 s p ccall_spec@(CCallSpec target cconv safety) fn args_r_to_l
 	 stk_offset   = d_after_r - s
 
          -- do the call
-         do_call      = unitOL (CCALL stk_offset (castPtr addr_of_marshaller))
+         do_call      = unitOL (CCALL stk_offset (castFunPtrToPtr addr_of_marshaller))
          -- slide and return
          wrapup       = mkSLIDE r_sizeW (d_after_r - r_sizeW - s)
                         `snocOL` RETURN_UBX r_rep
@@ -1102,7 +1103,7 @@ pushAtom d p (AnnLit lit)
 			    -- to be on the safe side we copy the string into
 			    -- a malloc'd area of memory.
                                 ioToBc (mallocBytes (n+1)) `thenBc` \ ptr ->
-                                recordMallocBc ptr         `thenBc_`
+                                recordMallocBc ptr `thenBc_`
                                 ioToBc (
                                    withForeignPtr fp $ \p -> do
 				      memcpy ptr p (fromIntegral n)
@@ -1314,10 +1315,12 @@ mkStackOffsets original_depth szsw
 -- -----------------------------------------------------------------------------
 -- The bytecode generator's monad
 
+type BcPtr = Either ItblPtr (Ptr ())
+
 data BcM_State 
    = BcM_State { 
 	nextlabel :: Int,		-- for generating local labels
-	malloced  :: [Ptr ()] }		-- ptrs malloced for current BCO
+	malloced  :: [BcPtr] }		-- thunks malloced for current BCO
 					-- Should be free()d when it is GCd
 
 newtype BcM r = BcM (BcM_State -> IO (BcM_State, r))
@@ -1351,13 +1354,17 @@ instance Monad BcM where
   (>>)  = thenBc_
   return = returnBc
 
-emitBc :: ([Ptr ()] -> ProtoBCO Name) -> BcM (ProtoBCO Name)
+emitBc :: ([BcPtr] -> ProtoBCO Name) -> BcM (ProtoBCO Name)
 emitBc bco
   = BcM $ \st -> return (st{malloced=[]}, bco (malloced st))
 
 recordMallocBc :: Ptr a -> BcM ()
 recordMallocBc a
-  = BcM $ \st -> return (st{malloced = castPtr a : malloced st}, ())
+  = BcM $ \st -> return (st{malloced = Right (castPtr a) : malloced st}, ())
+
+recordItblMallocBc :: ItblPtr -> BcM ()
+recordItblMallocBc a
+  = BcM $ \st -> return (st{malloced = Left a : malloced st}, ())
 
 getLabelBc :: BcM Int
 getLabelBc

compiler/ghci/ByteCodeInstr.lhs

@@ -11,6 +11,8 @@ module ByteCodeInstr (
 #include "HsVersions.h"
 #include "../includes/MachDeps.h"
 
+import ByteCodeItbls	( ItblPtr )
+
 import Outputable
 import Name
 import Id
@@ -38,7 +40,7 @@ data ProtoBCO a
 	-- what the BCO came from
 	protoBCOExpr       :: Either  [AnnAlt Id VarSet] (AnnExpr Id VarSet),
 	-- malloc'd pointers
-        protoBCOPtrs       :: [Ptr ()]
+        protoBCOPtrs       :: [Either ItblPtr (Ptr ())]
    }
 
 type LocalLabel = Int

compiler/ghci/ByteCodeItbls.lhs

@@ -6,10 +6,11 @@ ByteCodeItbls: Generate infotables for interpreter-made bytecodes
 \begin{code}
 {-# OPTIONS -optc-DNON_POSIX_SOURCE #-}
 
-module ByteCodeItbls ( ItblEnv, ItblPtr, mkITbls ) where
+module ByteCodeItbls ( ItblEnv, ItblPtr(..), itblCode, mkITbls ) where
 
 #include "HsVersions.h"
 
+import ByteCodeFFI	( newExec )
 import Name		( Name, getName )
 import NameEnv
 import SMRep		( typeCgRep )
@@ -35,7 +36,15 @@ import GHC.Ptr		( Ptr(..) )
 %************************************************************************
 
 \begin{code}
-type ItblPtr = Ptr StgInfoTable
+newtype ItblPtr = ItblPtr (Ptr ()) deriving Show
+
+itblCode :: ItblPtr -> Ptr ()
+itblCode (ItblPtr ptr)
+   = (castPtr ptr)
+#ifdef GHCI_TABLES_NEXT_TO_CODE
+                 `plusPtr` (wORD_SIZE * 2)
+#endif
+
 type ItblEnv = NameEnv (Name, ItblPtr)
 	-- We need the Name in the range so we know which
 	-- elements to filter out when unloading a module
@@ -107,16 +116,11 @@ make_constr_itbls cons
                  -- This is the only arch-dependent bit.
                  code = mkJumpToAddr entry_addr
              in
-                 do addr <- malloc_exec (sizeOf itbl)
+                 do addr <- newExec [itbl]
                     --putStrLn ("SIZE of itbl is " ++ show (sizeOf itbl))
                     --putStrLn ("# ptrs  of itbl is " ++ show ptrs)
                     --putStrLn ("# nptrs of itbl is " ++ show nptrs_really)
-                    poke addr itbl
-                    return (getName dcon, addr
-#ifdef GHCI_TABLES_NEXT_TO_CODE
-                                               `plusPtr` (2 * wORD_SIZE)
-#endif
-                           )
+                    return (getName dcon, ItblPtr (castFunPtrToPtr addr))
 
 
 -- Make code which causes a jump to the given address.  This is the
@@ -390,10 +394,4 @@ load :: Storable a => PtrIO a
 load = do addr <- advance
           lift (peek addr)
 
-foreign import ccall unsafe "allocateExec"
-  _allocateExec :: CUInt -> IO (Ptr a)
-
-malloc_exec :: Int -> IO (Ptr a)
-malloc_exec bytes = _allocateExec (fromIntegral bytes)
-
 \end{code}

compiler/ghci/ByteCodeLink.lhs

@@ -46,7 +46,7 @@ import GHC.Exts		( BCO#, newBCO#, unsafeCoerce#, Int#,
 
 import GHC.Arr		( Array(..) )
 import GHC.IOBase	( IO(..) )
-import GHC.Ptr		( Ptr(..) )
+import GHC.Ptr		( Ptr(..), castPtr )
 import GHC.Base		( writeArray#, RealWorld, Int(..) )
 \end{code}
 
@@ -124,7 +124,7 @@ linkBCO' ie ce (UnlinkedBCO nm arity insns_barr bitmap literalsSS ptrsSS itblsSS
             ptrs_parr = case ptrs_arr of Array lo hi parr -> parr
 
             itbls_arr = listArray (0, n_itbls-1) linked_itbls
-                        :: UArray Int ItblPtr
+
             itbls_barr = case itbls_arr of UArray lo hi barr -> barr
 
             literals_arr = listArray (0, n_literals-1) linked_literals
@@ -222,7 +222,7 @@ lookupName ce nm
 lookupIE :: ItblEnv -> Name -> IO (Ptr a)
 lookupIE ie con_nm 
    = case lookupNameEnv ie con_nm of
-        Just (_, Ptr a) -> return (Ptr a)
+        Just (_, a) -> return (castPtr (itblCode a))
         Nothing
            -> do -- try looking up in the object files.
                  let sym_to_find1 = nameToCLabel con_nm "con_info"

rts/Linker.c

@@ -10,7 +10,7 @@
 #include "PosixSource.h"
 #endif
 
-/* Linux needs _GNU_SOURCE to get RTLD_DEFAULT from <dlfcn.h> and 
+/* Linux needs _GNU_SOURCE to get RTLD_DEFAULT from <dlfcn.h> and
    MREMAP_MAYMOVE from <sys/mman.h>.
  */
 #ifdef __linux__
@@ -1161,13 +1161,12 @@ loadObj( char *path )
    void *map_addr = NULL;
 #else
    FILE *f;
-   int misalignment;
 #endif
    initLinker();
 
    /* debugBelch("loadObj %s\n", path ); */
 
-   /* Check that we haven't already loaded this object. 
+   /* Check that we haven't already loaded this object.
       Ignore requests to load multiple times */
    {
        ObjectCode *o;
@@ -1257,7 +1256,7 @@ loadObj( char *path )
 #define EXTRA_MAP_FLAGS 0
 #endif
 
-   oc->image = mmap(map_addr, n, PROT_EXEC|PROT_READ|PROT_WRITE, 
+   oc->image = mmap(map_addr, n, PROT_EXEC|PROT_READ|PROT_WRITE,
 		    MAP_PRIVATE|EXTRA_MAP_FLAGS, fd, 0);
    if (oc->image == MAP_FAILED)
       barf("loadObj: can't map `%s'", path);
@@ -1271,7 +1270,12 @@ loadObj( char *path )
    if (!f)
        barf("loadObj: can't read `%s'", path);
 
-#ifdef darwin_HOST_OS
+#   if defined(mingw32_HOST_OS)
+	// TODO: We would like to use allocateExec here, but allocateExec
+	//       cannot currently allocate blocks large enough.
+    oc->image = VirtualAlloc(NULL, oc->fileSize, MEM_RESERVE | MEM_COMMIT,
+                             PAGE_EXECUTE_READWRITE);
+#   elif defined(darwin_HOST_OS)
     // In a Mach-O .o file, all sections can and will be misaligned
     // if the total size of the headers is not a multiple of the
     // desired alignment. This is fine for .o files that only serve
@@ -1281,15 +1285,12 @@ loadObj( char *path )
     // We calculate the correct alignment from the header before
     // reading the file, and then we misalign oc->image on purpose so
     // that the actual sections end up aligned again.
-   misalignment = machoGetMisalignment(f);
-   oc->misalignment = misalignment;
-#else
-   misalignment = 0;
-#endif
-
+   oc->misalignment = machoGetMisalignment(f);
    oc->image = stgMallocBytes(oc->fileSize + misalignment, "loadObj(image)");
-   oc->image += misalignment;
-   
+#  else
+   oc->image = stgMallocBytes(oc->fileSize, "loadObj(image)");
+#  endif
+
    n = fread ( oc->image, 1, oc->fileSize, f );
    if (n != oc->fileSize)
       barf("loadObj: error whilst reading `%s'", path);
@@ -1402,9 +1403,13 @@ unloadObj( char *path )
 		prev->next = oc->next;
 	    }
 
-	    /* We're going to leave this in place, in case there are
-	       any pointers from the heap into it: */
-	    /* stgFree(oc->image); */
+	    // We're going to leave this in place, in case there are
+	    // any pointers from the heap into it:
+		// #ifdef mingw32_HOST_OS
+		//  VirtualFree(oc->image);
+		// #else
+	    //  stgFree(oc->image);
+	    // #endif
 	    stgFree(oc->fileName);
 	    stgFree(oc->symbols);
 	    stgFree(oc->sections);
@@ -1479,7 +1484,7 @@ static void addSection ( ObjectCode* oc, SectionKind kind,
 
 /*
   ocAllocateJumpIslands
-  
+
   Allocate additional space at the end of the object file image to make room
   for jump islands.
   

rts/sm/Storage.c

@@ -979,6 +979,11 @@ calcNeeded(void)
    in the page, and when the page is emptied (all objects on the page
    are free) we free the page again, not forgetting to make it
    non-executable.
+
+   TODO: The inability to handle objects bigger than BLOCK_SIZE_W means that
+         the linker cannot use allocateExec for loading object code files
+         on Windows. Once allocateExec can handle larger objects, the linker
+         should be modified to use allocateExec instead of VirtualAlloc.
    ------------------------------------------------------------------------- */
 
 static bdescr *exec_block;