Rebuilding GHC on Mac OSX PPC

[Joel Reymont]

More on allocateExec... I see this at the end of ./ghc/compiler/ghci/ 
ByteCodeItbls.lhs

foreign import ccall unsafe "allocateExec"
   _allocateExec :: CUInt -> IO (Ptr a)

malloc_exec :: Int -> IO (Ptr a)
malloc_exec bytes = _allocateExec (fromIntegral bytes)

It does not appear that malloc_exec is used anywhere else but here  
it's used in the function below. I don't know where allocateExec is  
supposed to be coming from.

-- Assumes constructors are numbered from zero, not one
make_constr_itbls :: [DataCon] -> IO ItblEnv
make_constr_itbls cons
    | listLengthCmp cons 8 /= GT -- <= 8 elements in the list
    = do is <- mapM mk_vecret_itbl (zip cons [0..])
         return (mkItblEnv is)
    | otherwise
    = do is <- mapM mk_dirret_itbl (zip cons [0..])
         return (mkItblEnv is)
      where
         mk_vecret_itbl (dcon, conNo)
            = mk_itbl dcon conNo (vecret_entry conNo)
         mk_dirret_itbl (dcon, conNo)
            = mk_itbl dcon conNo stg_interp_constr_entry

         mk_itbl :: DataCon -> Int -> Ptr () -> IO (Name,ItblPtr)
         mk_itbl dcon conNo entry_addr
            = let rep_args = [ (typeCgRep arg,arg)
                             | arg <- dataConRepArgTys dcon ]
                  (tot_wds, ptr_wds, _) = mkVirtHeapOffsets rep_args

                  ptrs  = ptr_wds
                  nptrs = tot_wds - ptr_wds
                  nptrs_really
                     | ptrs + nptrs >= mIN_SIZE_NonUpdHeapObject = nptrs
                     | otherwise = mIN_SIZE_NonUpdHeapObject - ptrs
                  itbl  = StgInfoTable {
                            ptrs  = fromIntegral ptrs,
                            nptrs = fromIntegral nptrs_really,
                            tipe  = fromIntegral cONSTR,
                            srtlen = fromIntegral conNo,
                            code  = code
                         }
                  -- Make a piece of code to jump to "entry_label".
                  -- This is the only arch-dependent bit.
                  code = mkJumpToAddr entry_addr
              in
                  do addr <- malloc_exec (sizeOf 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 `plusPtr` (2 *  
wORD_SIZE))