X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Fparser%2FLexer.x;h=6b73981350333f1517e70435bc5e7e717fa6f397;hp=2e17b8f1284712513f58120f1dcc6d3c3bd39373;hb=5fa086c51816f09d03fb1a089dde64df6bd2d8a3;hpb=a6f2d598e1e7760d334d1b5ea0b7745e66835e11

diff --git a/compiler/parser/Lexer.x b/compiler/parser/Lexer.x
index 2e17b8f..6b73981 100644
--- a/compiler/parser/Lexer.x
+++ b/compiler/parser/Lexer.x
@@ -32,6 +32,7 @@
 
 {
 -- XXX The above flags turn off warnings in the generated code:
+{-# LANGUAGE BangPatterns #-}
 {-# OPTIONS_GHC -fno-warn-unused-matches #-}
 {-# OPTIONS_GHC -fno-warn-unused-binds #-}
 {-# OPTIONS_GHC -fno-warn-unused-imports #-}
@@ -140,7 +141,7 @@ haskell :-
 
 -- everywhere: skip whitespace and comments
 $white_no_nl+ 				;
-$tab+         { warn Opt_WarnTabs (text "Tab character") }
+$tab+         { warn Opt_WarnTabs (text "Warning: Tab character") }
 
 -- Everywhere: deal with nested comments.  We explicitly rule out
 -- pragmas, "{-#", so that we don't accidentally treat them as comments.
@@ -210,7 +211,7 @@ $tab+         { warn Opt_WarnTabs (text "Tab character") }
 -- context if the curly brace is missing.
 -- Careful! This stuff is quite delicate.
 <layout, layout_do> {
-  \{ / { notFollowedBy '-' }		{ pop_and open_brace }
+  \{ / { notFollowedBy '-' }		{ hopefully_open_brace }
 	-- we might encounter {-# here, but {- has been handled already
   \n					;
   ^\# (line)?				{ begin line_prag1 }
@@ -308,6 +309,10 @@ $tab+         { warn Opt_WarnTabs (text "Tab character") }
   \$ @varid / { ifExtension thEnabled }	{ skip_one_varid ITidEscape }
   "$("	    / { ifExtension thEnabled }	{ token ITparenEscape }
 
+-- For backward compatibility, accept the old dollar syntax
+  "[$" @varid "|"  / { ifExtension qqEnabled }
+                     { lex_quasiquote_tok }
+
   "[" @varid "|"  / { ifExtension qqEnabled }
                      { lex_quasiquote_tok }
 }
@@ -452,6 +457,7 @@ data Token
   | ITdynamic
   | ITsafe
   | ITthreadsafe
+  | ITinterruptible
   | ITunsafe
   | ITstdcallconv
   | ITccallconv
@@ -596,6 +602,7 @@ isSpecial ITlabel     	= True
 isSpecial ITdynamic   	= True
 isSpecial ITsafe    	= True
 isSpecial ITthreadsafe 	= True
+isSpecial ITinterruptible = True
 isSpecial ITunsafe    	= True
 isSpecial ITccallconv   = True
 isSpecial ITstdcallconv = True
@@ -658,6 +665,7 @@ reservedWordsFM = listToUFM $
 	( "dynamic",	ITdynamic,	 bit ffiBit),
 	( "safe",	ITsafe,		 bit ffiBit),
 	( "threadsafe",	ITthreadsafe,	 bit ffiBit),  -- ToDo: remove
+	( "interruptible", ITinterruptible, bit ffiBit),
 	( "unsafe",	ITunsafe,	 bit ffiBit),
 	( "stdcall",    ITstdcallconv,	 bit ffiBit),
 	( "ccall",      ITccallconv,	 bit ffiBit),
@@ -749,6 +757,19 @@ pop :: Action
 pop _span _buf _len = do _ <- popLexState
                          lexToken
 
+hopefully_open_brace :: Action
+hopefully_open_brace span buf len
+ = do relaxed <- extension relaxedLayout
+      ctx <- getContext
+      (AI l _) <- getInput
+      let offset = srcLocCol l
+          isOK = relaxed ||
+                 case ctx of
+                 Layout prev_off : _ -> prev_off < offset
+                 _                   -> True
+      if isOK then pop_and open_brace span buf len
+              else failSpanMsgP span (text "Missing block")
+
 pop_and :: Action -> Action
 pop_and act span buf len = do _ <- popLexState
                               act span buf len
@@ -1099,10 +1120,12 @@ new_layout_context strict span _buf _len = do
     (AI l _) <- getInput
     let offset = srcLocCol l
     ctx <- getContext
+    nondecreasing <- extension nondecreasingIndentation
+    let strict' = strict || not nondecreasing
     case ctx of
 	Layout prev_off : _  | 
-	   (strict     && prev_off >= offset  ||
-	    not strict && prev_off > offset) -> do
+	   (strict'     && prev_off >= offset  ||
+	    not strict' && prev_off > offset) -> do
 		-- token is indented to the left of the previous context.
 		-- we must generate a {} sequence now.
 		pushLexState layout_left
@@ -1753,6 +1776,10 @@ recBit :: Int
 recBit = 22 -- rec
 alternativeLayoutRuleBit :: Int
 alternativeLayoutRuleBit = 23
+relaxedLayoutBit :: Int
+relaxedLayoutBit = 24
+nondecreasingIndentationBit :: Int
+nondecreasingIndentationBit = 25
 
 always :: Int -> Bool
 always           _     = True
@@ -1796,6 +1823,10 @@ oldQualOps :: Int -> Bool
 oldQualOps flags = not (newQualOps flags)
 alternativeLayoutRule :: Int -> Bool
 alternativeLayoutRule flags = testBit flags alternativeLayoutRuleBit
+relaxedLayout :: Int -> Bool
+relaxedLayout flags = testBit flags relaxedLayoutBit
+nondecreasingIndentation :: Int -> Bool
+nondecreasingIndentation flags = testBit flags nondecreasingIndentationBit
 
 -- PState for parsing options pragmas
 --
@@ -1849,6 +1880,8 @@ mkPState flags buf loc =
                .|. rawTokenStreamBit `setBitIf` dopt Opt_KeepRawTokenStream flags
                .|. newQualOpsBit `setBitIf` xopt Opt_NewQualifiedOperators flags
                .|. alternativeLayoutRuleBit `setBitIf` xopt Opt_AlternativeLayoutRule flags
+               .|. relaxedLayoutBit `setBitIf` xopt Opt_RelaxedLayout flags
+               .|. nondecreasingIndentationBit `setBitIf` xopt Opt_NondecreasingIndentation flags
       --
       setBitIf :: Int -> Bool -> Int
       b `setBitIf` cond | cond      = bit b