FIX #2049, another problem with the module context on :reload

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

diff --git a/compiler/ghci/ByteCodeGen.lhs b/compiler/ghci/ByteCodeGen.lhs
index 3f147c5..bb0f591 100644 (file)
--- a/compiler/ghci/ByteCodeGen.lhs
+++ b/compiler/ghci/ByteCodeGen.lhs
@@ -5,6 +5,13 @@
 ByteCodeGen: Generate bytecode from Core
 
 \begin{code}
+{-# OPTIONS -w #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and fix
+-- any warnings in the module. See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
+-- for details
+
 module ByteCodeGen ( UnlinkedBCO, byteCodeGen, coreExprToBCOs ) where
 
 #include "HsVersions.h"
@@ -171,17 +178,19 @@ mkProtoBCO nm instrs_ordlist origin arity bitmap_size bitmap is_ret mallocd_bloc
         -- (hopefully rare) cases when the (overestimated) stack use
         -- exceeds iNTERP_STACK_CHECK_THRESH.
         maybe_with_stack_check
-          | is_ret = peep_d
-               -- don't do stack checks at return points;
+          | is_ret && stack_usage < aP_STACK_SPLIM = peep_d
+               -- don't do stack checks at return points,
                -- everything is aggregated up to the top BCO
-               -- (which must be a function)
-           | stack_overest >= iNTERP_STACK_CHECK_THRESH
-           = STKCHECK stack_overest : peep_d
+               -- (which must be a function).
+                -- That is, unless the stack usage is >= AP_STACK_SPLIM,
+                -- see bug #1466.
+           | stack_usage >= iNTERP_STACK_CHECK_THRESH
+           = STKCHECK stack_usage : peep_d
            | otherwise
            = peep_d    -- the supposedly common case
              
         -- We assume that this sum doesn't wrap
-        stack_overest = sum (map bciStackUse peep_d)
+        stack_usage = sum (map bciStackUse peep_d)
 
         -- Merge local pushes
         peep_d = peep (fromOL instrs_ordlist)
@@ -418,9 +427,15 @@ schemeE d s p (AnnLet binds (_,body))
               return (push_code `appOL` more_push_code)
 
          alloc_code = toOL (zipWith mkAlloc sizes arities)
-          where mkAlloc sz 0     = ALLOC_AP sz
+          where mkAlloc sz 0
+                    | is_tick     = ALLOC_AP_NOUPD sz
+                    | otherwise   = ALLOC_AP sz
                 mkAlloc sz arity = ALLOC_PAP arity sz
 
+         is_tick = case binds of 
+                     AnnNonRec id _ -> occNameFS (getOccName id) == tickFS
+                     _other -> False
+
         compile_bind d' fvs x rhs size arity off = do
                bco <- schemeR fvs (x,rhs)
                build_thunk d' fvs size bco off arity
@@ -1376,13 +1391,14 @@ lookupBCEnv_maybe = lookupFM
 idSizeW :: Id -> Int
 idSizeW id = cgRepSizeW (typeCgRep (idType id))
 
+-- See bug #1257
 unboxedTupleException :: a
 unboxedTupleException 
    = throwDyn 
-        (Panic 
-           ("Bytecode generator can't handle unboxed tuples.  Possibly due\n" ++
-            "\tto foreign import/export decls in source.  Workaround:\n" ++
-            "\tcompile this module to a .o file, then restart session."))
+        (ProgramError 
+           ("Error: bytecode compiler can't handle unboxed tuples.\n"++
+            "  Possibly due to foreign import/export decls in source.\n"++
+            "  Workaround: use -fobject-code, or compile this module to .o separately."))
 
 
 mkSLIDE n d = if d == 0 then nilOL else unitOL (SLIDE n d)
@@ -1509,5 +1525,7 @@ newUnique = BcM $
 newId :: Type -> BcM Id
 newId ty = do 
     uniq <- newUnique
-    return $ mkSysLocal FSLIT("ticked") uniq ty
+    return $ mkSysLocal tickFS uniq ty
+
+tickFS = FSLIT("ticked")
 \end{code}