X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Fparser%2FLexer.x;h=cae53499fedf05324887c9b17af7f4856367a02b;hp=dca51e47267d1d64272bd7eefcdded2adb5945f5;hb=60762c678c83e370609001addc8f52efcd657139;hpb=2fe38b5fb0957f9428864afd69ad3ccd82fae3d0

diff --git a/compiler/parser/Lexer.x b/compiler/parser/Lexer.x
index dca51e4..cae5349 100644
--- a/compiler/parser/Lexer.x
+++ b/compiler/parser/Lexer.x
@@ -1144,6 +1144,7 @@ setLine code span buf len = do
 setFile :: Int -> Action
 setFile code span buf len = do
   let file = lexemeToFastString (stepOn buf) (len-2)
+  setAlrLastLoc noSrcSpan
   setSrcLoc (mkSrcLoc file (srcSpanEndLine span) (srcSpanEndCol span))
   _ <- popLexState
   pushLexState code
@@ -1289,7 +1290,7 @@ finish_char_tok loc ch	-- We've already seen the closing quote
 				return (L (mkSrcSpan loc end) (ITprimchar ch))
 			_other ->
 				return (L (mkSrcSpan loc end) (ITchar ch))
-	        else do
+	    else do
 		   return (L (mkSrcSpan loc end) (ITchar ch))
 
 lex_char :: Char -> AlexInput -> P Char
@@ -1498,10 +1499,19 @@ data PState = PState {
 	context	   :: [LayoutContext],
 	lex_state  :: [Int],
         -- Used in the alternative layout rule:
+        -- These tokens are the next ones to be sent out. They are
+        -- just blindly emitted, without the rule looking at them again:
         alr_pending_implicit_tokens :: [Located Token],
+        -- This is the next token to be considered or, if it is Nothing,
+        -- we need to get the next token from the input stream:
         alr_next_token :: Maybe (Located Token),
+        -- This is what we consider to be the locatino of the last token
+        -- emitted:
         alr_last_loc :: SrcSpan,
+        -- The stack of layout contexts:
         alr_context :: [ALRContext],
+        -- Are we expecting a '{'? If it's Just, then the ALRLayout tells
+        -- us what sort of layout the '{' will open:
         alr_expecting_ocurly :: Maybe ALRLayout
      }
 	-- last_loc and last_len are used when generating error messages,
@@ -1981,8 +1991,17 @@ alternativeLayoutRuleToken t
          mExpectingOCurly <- getAlrExpectingOCurly
          let thisLoc = getLoc t
              thisCol = srcSpanStartCol thisLoc
-             newLine = srcSpanStartLine thisLoc > srcSpanEndLine lastLoc
+             newLine = (lastLoc == noSrcSpan)
+                    || (srcSpanStartLine thisLoc > srcSpanEndLine lastLoc)
          case (unLoc t, context, mExpectingOCurly) of
+             -- This case handles a GHC extension to the original H98
+             -- layout rule...
+             (ITocurly, _, Just _) ->
+                 do setAlrExpectingOCurly Nothing
+                    setALRContext (ALRNoLayout (containsCommas ITocurly) : context)
+                    return t
+             -- ...and makes this case unnecessary
+             {-
              -- I think our implicit open-curly handling is slightly
              -- different to John's, in how it interacts with newlines
              -- and "in"
@@ -1990,6 +2009,7 @@ alternativeLayoutRuleToken t
                  do setAlrExpectingOCurly Nothing
                     setNextToken t
                     lexTokenAlr
+             -}
              (_, ALRLayout _ col : ls, Just expectingOCurly)
               | (thisCol > col) ||
                 (thisCol == col &&
@@ -2000,9 +2020,9 @@ alternativeLayoutRuleToken t
                     return (L thisLoc ITocurly)
               | otherwise ->
                  do setAlrExpectingOCurly Nothing
-                    setPendingImplicitTokens [L thisLoc ITccurly]
+                    setPendingImplicitTokens [L lastLoc ITccurly]
                     setNextToken t
-                    return (L thisLoc ITocurly)
+                    return (L lastLoc ITocurly)
              (_, _, Just expectingOCurly) ->
                  do setAlrExpectingOCurly Nothing
                     setALRContext (ALRLayout expectingOCurly thisCol : context)
@@ -2098,6 +2118,10 @@ isNonDecreasingIntentation _           = False
 containsCommas :: Token -> Bool
 containsCommas IToparen = True
 containsCommas ITobrack = True
+-- John doesn't have {} as containing commas, but records contain them,
+-- which caused a problem parsing Cabal's Distribution.Simple.InstallDirs
+-- (defaultInstallDirs).
+containsCommas ITocurly = True
 -- GHC Extensions:
 containsCommas IToubxparen = True
 containsCommas _        = False