Add Outputable.blankLine and use it

compiler/cmm/PprC.hs

@@ -92,7 +92,7 @@ writeCs dflags handle cmms
 --
 
 pprC :: RawCmm -> SDoc
-pprC (Cmm tops) = vcat $ intersperse (text "") $ map pprTop tops
+pprC (Cmm tops) = vcat $ intersperse blankLine $ map pprTop tops
 
 --
 -- top level procs
@@ -107,7 +107,7 @@ pprTop (CmmProc info clbl _params (ListGraph blocks)) =
         [] -> empty
          -- the first block doesn't get a label:
         (BasicBlock _ stmts : rest) -> vcat [
-	   text "",
+	   blankLine,
 	   extern_decls,
            (if (externallyVisibleCLabel clbl)
                     then mkFN_ else mkIF_) (pprCLabel clbl) <+> lbrace,

compiler/cmm/PprCmm.hs

@@ -115,7 +115,7 @@ instance Outputable CmmInfo where
 -----------------------------------------------------------------------------
 
 pprCmm :: (Outputable d, Outputable info, Outputable g) => GenCmm d info g -> SDoc
-pprCmm (Cmm tops) = vcat $ intersperse (text "") $ map pprTop tops
+pprCmm (Cmm tops) = vcat $ intersperse blankLine $ map pprTop tops
 
 -- --------------------------------------------------------------------------
 -- Top level `procedure' blocks.
@@ -506,9 +506,8 @@ pprLit :: CmmLit -> SDoc
 pprLit lit = case lit of
     CmmInt i rep ->
         hcat [ (if i < 0 then parens else id)(integer i)
-             , (if rep == wordWidth
-                    then empty 
-                    else space <> dcolon <+> ppr rep) ]
+             , ppUnless (rep == wordWidth) $
+               space <> dcolon <+> ppr rep ]
 
     CmmFloat f rep     -> hsep [ rational f, dcolon, ppr rep ]
     CmmLabel clbl      -> pprCLabel clbl

compiler/cmm/ZipCfgCmmRep.hs

@@ -459,10 +459,9 @@ pprMiddle stmt = pp_stmt <+> pp_debug
     	-- call "ccall" foo(x, y)[r1, r2];
     	-- ToDo ppr volatile
     	MidForeignCall safety target results args ->
-    	    hsep [ if null results
-    	              then empty
-    	              else parens (commafy $ map ppr results) <+> equals,
-                      ppr_safety safety,
+    	    hsep [ ppUnless (null results) $
+    	              parens (commafy $ map ppr results) <+> equals,
+                   ppr_safety safety,
     	           ptext $ sLit "call", 
     	           ppr_call_target target <> parens (commafy $ map ppr args) <> semi]
 

compiler/coreSyn/CoreLint.lhs

@@ -650,7 +650,7 @@ initL :: LintM a -> Maybe Message {- errors -}
 initL m
   = case unLintM m [] emptyTvSubst emptyBag of
       (_, errs) | isEmptyBag errs -> Nothing
-		| otherwise	  -> Just (vcat (punctuate (text "") (bagToList errs)))
+		| otherwise	  -> Just (vcat (punctuate blankLine (bagToList errs)))
 \end{code}
 
 \begin{code}

compiler/coreSyn/PprCore.lhs

@@ -71,13 +71,16 @@ pprTopBinds binds = vcat (map pprTopBind binds)
 
 pprTopBind :: OutputableBndr a => Bind a -> SDoc
 pprTopBind (NonRec binder expr)
- = ppr_binding (binder,expr) $$ text ""
+ = ppr_binding (binder,expr) $$ blankLine
 
-pprTopBind (Rec binds)
+pprTopBind (Rec [])
+  = ptext (sLit "Rec { }")
+pprTopBind (Rec (b:bs))
   = vcat [ptext (sLit "Rec {"),
-	  vcat (map ppr_binding binds),
+	  ppr_binding b,
+	  vcat [blankLine $$ ppr_binding b | b <- bs],
 	  ptext (sLit "end Rec }"),
-	  text ""]
+	  blankLine]
 \end{code}
 
 \begin{code}

compiler/deSugar/Desugar.lhs

@@ -243,7 +243,7 @@ addExportFlags target exports keep_alive prs rules
 ppr_ds_rules :: [CoreRule] -> SDoc
 ppr_ds_rules [] = empty
 ppr_ds_rules rules
-  = text "" $$ text "-------------- DESUGARED RULES -----------------" $$
+  = blankLine $$ text "-------------- DESUGARED RULES -----------------" $$
     pprRules rules
 \end{code}
 

compiler/hsSyn/HsDecls.lhs

@@ -225,7 +225,7 @@ instance OutputableBndr name => Outputable (HsGroup name) where
 		ppr_ds foreign_decls]
 	where
 	  ppr_ds [] = empty
-	  ppr_ds ds = text "" $$ vcat (map ppr ds)
+	  ppr_ds ds = blankLine $$ vcat (map ppr ds)
 
 data SpliceDecl id = SpliceDecl (Located (HsExpr id))	-- Top level splice
 

compiler/main/DriverMkDepend.hs

@@ -352,7 +352,7 @@ dumpModCycles dflags mod_summaries
     cycles = [ c | CyclicSCC c <- GHC.topSortModuleGraph True mod_summaries Nothing ]
 
     pp_cycles = vcat [ (ptext (sLit "---------- Cycle") <+> int n <+> ptext (sLit "----------"))
-                        $$ pprCycle c $$ text ""
+                        $$ pprCycle c $$ blankLine
                      | (n,c) <- [1..] `zip` cycles ]
 
 pprCycle :: [ModSummary] -> SDoc

compiler/main/ErrUtils.lhs

@@ -230,10 +230,10 @@ dumpIfSet_dyn_or dflags flags hdr doc
 
 mkDumpDoc :: String -> SDoc -> SDoc
 mkDumpDoc hdr doc 
-   = vcat [text "", 
+   = vcat [blankLine,
 	   line <+> text hdr <+> line,
 	   doc,
-	   text ""]
+	   blankLine]
      where 
         line = text (replicate 20 '=')
 

compiler/simplCore/SimplMonad.lhs

@@ -243,10 +243,10 @@ pprSimplCount VerySimplZero    = ptext (sLit "Total ticks: ZERO!")
 pprSimplCount VerySimplNonZero = ptext (sLit "Total ticks: NON-ZERO!")
 pprSimplCount (SimplCount { ticks = tks, details = dts, log1 = l1, log2 = l2 })
   = vcat [ptext (sLit "Total ticks:    ") <+> int tks,
-	  text "",
+	  blankLine,
 	  pprTickCounts (fmToList dts),
 	  if verboseSimplStats then
-		vcat [text "",
+		vcat [blankLine,
 		      ptext (sLit "Log (most recent first)"),
 		      nest 4 (vcat (map ppr l1) $$ vcat (map ppr l2))]
 	  else empty

compiler/stgSyn/StgLint.lhs

@@ -316,7 +316,7 @@ initL (LintM m)
     if isEmptyBag errs then
         Nothing
     else
-        Just (vcat (punctuate (text "") (bagToList errs)))
+        Just (vcat (punctuate blankLine (bagToList errs)))
     }
 
 instance Monad LintM where

compiler/utils/Outputable.lhs

@@ -25,6 +25,7 @@ module Outputable (
 	parens, cparen, brackets, braces, quotes, doubleQuotes, angleBrackets,
 	semi, comma, colon, dcolon, space, equals, dot, arrow,
 	lparen, rparen, lbrack, rbrack, lbrace, rbrace, underscore,
+	blankLine,
 	(<>), (<+>), hcat, hsep, 
 	($$), ($+$), vcat,
 	sep, cat, 
@@ -56,7 +57,7 @@ module Outputable (
 	ifPprDebug, qualName, qualModule,
 	mkErrStyle, defaultErrStyle, defaultDumpStyle, defaultUserStyle,
         mkUserStyle, Depth(..),
-
+	
 	-- * Error handling and debugging utilities
 	pprPanic, assertPprPanic, pprPanicFastInt, pprPgmError, 
 	pprTrace, warnPprTrace,
@@ -291,7 +292,7 @@ hPrintDump h doc = do
    Pretty.printDoc PageMode h (better_doc defaultDumpStyle)
    hFlush h
  where
-   better_doc = doc $$ text ""
+   better_doc = doc $$ blankLine
 
 printForUser :: Handle -> PrintUnqualified -> SDoc -> IO ()
 printForUser handle unqual doc 
@@ -397,23 +398,24 @@ quotes d sty = case show pp_d of
 	       pp_d = d sty
 
 semi, comma, colon, equals, space, dcolon, arrow, underscore, dot :: SDoc
-lparen, rparen, lbrack, rbrack, lbrace, rbrace :: SDoc
-
-semi _sty   = Pretty.semi
-comma _sty  = Pretty.comma
-colon _sty  = Pretty.colon
-equals _sty = Pretty.equals
-space _sty  = Pretty.space
-dcolon _sty = Pretty.ptext (sLit "::")
-arrow  _sty = Pretty.ptext (sLit "->")
-underscore  = char '_'
-dot	    = char '.'
-lparen _sty = Pretty.lparen
-rparen _sty = Pretty.rparen
-lbrack _sty = Pretty.lbrack
-rbrack _sty = Pretty.rbrack
-lbrace _sty = Pretty.lbrace
-rbrace _sty = Pretty.rbrace
+lparen, rparen, lbrack, rbrack, lbrace, rbrace, blankLine :: SDoc
+
+blankLine _sty = Pretty.ptext (sLit "")
+dcolon _sty    = Pretty.ptext (sLit "::")
+arrow  _sty    = Pretty.ptext (sLit "->")
+semi _sty      = Pretty.semi
+comma _sty     = Pretty.comma
+colon _sty     = Pretty.colon
+equals _sty    = Pretty.equals
+space _sty     = Pretty.space
+underscore     = char '_'
+dot	       = char '.'
+lparen _sty    = Pretty.lparen
+rparen _sty    = Pretty.rparen
+lbrack _sty    = Pretty.lbrack
+rbrack _sty    = Pretty.rbrack
+lbrace _sty    = Pretty.lbrace
+rbrace _sty    = Pretty.rbrace
 
 nest :: Int -> SDoc -> SDoc
 -- ^ Indent 'SDoc' some specified amount