Add {-# OPTIONS_GHC -w #-} and some blurb to all compiler modules

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

diff --git a/compiler/ghci/ByteCodeGen.lhs b/compiler/ghci/ByteCodeGen.lhs
index 444fe87..a67d003 100644 (file)
--- a/compiler/ghci/ByteCodeGen.lhs
+++ b/compiler/ghci/ByteCodeGen.lhs
@@ -5,6 +5,13 @@
 ByteCodeGen: Generate bytecode from Core
 
 \begin{code}
+{-# OPTIONS_GHC -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/WorkingConventions#Warnings
+-- for details
+
 module ByteCodeGen ( UnlinkedBCO, byteCodeGen, coreExprToBCOs ) where
 
 #include "HsVersions.h"
@@ -435,18 +442,24 @@ schemeE d s p (AnnLet binds (_,body))
      thunk_codes <- sequence compile_binds
      return (alloc_code `appOL` concatOL thunk_codes `appOL` body_code)
 
--- introduce a let binding for a ticked case expression. This rule *should* only fire when the
--- expression was not already let-bound (the code gen for let bindings should take care of that). 
--- Todo: we call exprFreeVars on a deAnnotated expression, this may not be the best way
--- to calculate the free vars but it seemed like the least intrusive thing to do
+-- introduce a let binding for a ticked case expression. This rule
+-- *should* only fire when the expression was not already let-bound
+-- (the code gen for let bindings should take care of that).  Todo: we
+-- call exprFreeVars on a deAnnotated expression, this may not be the
+-- best way to calculate the free vars but it seemed like the least
+-- intrusive thing to do
 schemeE d s p exp@(AnnCase {})
-   | Just (tickInfo, _exp) <- isTickedExp' exp = do 
-        let fvs = exprFreeVars $ deAnnotate' exp
-        let ty = exprType $ deAnnotate' exp
-        id <- newId ty
-        -- Todo: is emptyVarSet correct on the next line?
-        let letExp = AnnLet (AnnNonRec id (fvs, exp)) (emptyVarSet, AnnVar id)
-        schemeE d s p letExp
+   | Just (tickInfo,rhs) <- isTickedExp' exp
+   = if isUnLiftedType ty
+        then schemeE d s p (snd rhs)
+        else do
+          id <- newId ty
+          -- Todo: is emptyVarSet correct on the next line?
+          let letExp = AnnLet (AnnNonRec id (fvs, exp)) (emptyVarSet, AnnVar id)
+          schemeE d s p letExp
+   where exp' = deAnnotate' exp
+         fvs  = exprFreeVars exp'
+         ty   = exprType exp'
 
 schemeE d s p (AnnCase scrut bndr _ [(DataAlt dc, [bind1, bind2], rhs)])
    | isUnboxedTupleCon dc, VoidArg <- typeCgRep (idType bind1)
@@ -1370,13 +1383,14 @@ 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)