X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Fparser%2FLexer.x;h=83049181146cd12d0235f56f1ec7006302f8614e;hb=423d477bfecd490de1449c59325c8776f91d7aac;hp=cd578b372fe9dc2a2508ec8dc5bfa6cbe3fd5e6e;hpb=2b3f006bf539baa933a4207f0b24a0ed06b533a0;p=ghc-hetmet.git diff --git a/ghc/compiler/parser/Lexer.x b/ghc/compiler/parser/Lexer.x index cd578b3..8304918 100644 --- a/ghc/compiler/parser/Lexer.x +++ b/ghc/compiler/parser/Lexer.x @@ -22,10 +22,11 @@ { module Lexer ( - Token(..), Token__(..), lexer, mkPState, showPFailed, - P(..), ParseResult(..), setSrcLocFor, getSrcLoc, - failMsgP, failLocMsgP, srcParseFail, - popContext, pushCurrentContext, + Token(..), lexer, mkPState, PState(..), + P(..), ParseResult(..), getSrcLoc, + failLocMsgP, failSpanMsgP, srcParseFail, + popContext, pushCurrentContext, setLastToken, setSrcLoc, + getLexState, popLexState, pushLexState ) where #include "HsVersions.h" @@ -39,7 +40,7 @@ import SrcLoc import UniqFM import CmdLineOpts import Ctype -import Util ( maybePrefixMatch ) +import Util ( maybePrefixMatch, readRational ) import DATA_BITS import Char @@ -108,7 +109,8 @@ $white_no_nl+ ; -- have to exclude those. -- The regex says: "munch all the characters after the dashes, as long as -- the first one is not a symbol". -"--"\-* ([^$symbol] .*)? ; +"--"\-* [^$symbol] .* ; +"--"\-* / { atEOL } ; -- 'bol' state: beginning of a line. Slurp up all the whitespace (including -- blank lines) until we find a non-whitespace character, then do layout @@ -123,6 +125,7 @@ $white_no_nl+ ; \n ; ^\# (line)? { begin line_prag1 } ^\# pragma .* \n ; -- GCC 3.3 CPP generated, apparently + ^\# \! .* \n ; -- #!, for scripts () { do_bol } } @@ -151,15 +154,17 @@ $white_no_nl+ ; -- single-line line pragmas, of the form -- # "" \n - $digit+ { set_line line_prag1a } - \" [$graphic \ ]* \" { set_file line_prag1b } + $digit+ { setLine line_prag1a } + \" [$graphic \ ]* \" { setFile line_prag1b } .* { pop } -- Haskell-style line pragmas, of the form -- {-# LINE "" #-} - $digit+ { set_line line_prag2a } - \" [$graphic \ ]* \" { set_file line_prag2b } - "#-}" { pop } + $digit+ { setLine line_prag2a } + \" [$graphic \ ]* \" { setFile line_prag2b } + "#-}"|"-}" { pop } + -- NOTE: accept -} at the end of a LINE pragma, for compatibility + -- with older versions of GHC which generated these. <0,glaexts> { "{-#" $whitechar* (SPECIALI[SZ]E|speciali[sz]e) @@ -173,6 +178,7 @@ $white_no_nl+ ; { token ITdeprecated_prag } "{-#" $whitechar* (SCC|scc) { token ITscc_prag } "{-#" $whitechar* (CORE|core) { token ITcore_prag } + "{-#" $whitechar* (UNPACK|unpack) { token ITunpack_prag } "{-#" { nested_comment } @@ -297,9 +303,7 @@ unsafeAt arr i = arr ! i -- ----------------------------------------------------------------------------- -- The token type -data Token = T SrcSpan Token__ - -data Token__ +data Token = ITas -- Haskell keywords | ITcase | ITclass @@ -348,6 +352,7 @@ data Token__ | ITline_prag | ITscc_prag | ITcore_prag -- hdaume: core annotations + | ITunpack_prag | ITclose_prag | ITdotdot -- reserved symbols @@ -439,7 +444,7 @@ data Token__ deriving Show -- debugging #endif -isSpecial :: Token__ -> Bool +isSpecial :: Token -> Bool -- If we see M.x, where x is a keyword, but -- is special, we treat is as just plain M.x, -- not as a keyword. @@ -541,30 +546,30 @@ reservedSymsFM = listToUFM $ -- ----------------------------------------------------------------------------- -- Lexer actions -type Action = SrcSpan -> StringBuffer -> Int -> P Token +type Action = SrcSpan -> StringBuffer -> Int -> P (Located Token) -special :: Token__ -> Action -special tok span _buf len = return (T span tok) +special :: Token -> Action +special tok span _buf len = return (L span tok) -token, layout_token :: Token__ -> Action -token t span buf len = return (T span t) -layout_token t span buf len = pushLexState layout >> return (T span t) +token, layout_token :: Token -> Action +token t span buf len = return (L span t) +layout_token t span buf len = pushLexState layout >> return (L span t) -idtoken :: (StringBuffer -> Int -> Token__) -> Action -idtoken f span buf len = return (T span $! (f buf len)) +idtoken :: (StringBuffer -> Int -> Token) -> Action +idtoken f span buf len = return (L span $! (f buf len)) -skip_one_varid :: (FastString -> Token__) -> Action +skip_one_varid :: (FastString -> Token) -> Action skip_one_varid f span buf len - = return (T span $! f (lexemeToFastString (stepOn buf) (len-1))) + = return (L span $! f (lexemeToFastString (stepOn buf) (len-1))) -strtoken :: (String -> Token__) -> Action +strtoken :: (String -> Token) -> Action strtoken f span buf len = - return (T span $! (f $! lexemeToString buf len)) + return (L span $! (f $! lexemeToString buf len)) -init_strtoken :: Int -> (String -> Token__) -> Action +init_strtoken :: Int -> (String -> Token) -> Action -- like strtoken, but drops the last N character(s) init_strtoken drop f span buf len = - return (T span $! (f $! lexemeToString buf (len-drop))) + return (L span $! (f $! lexemeToString buf (len-drop))) begin :: Int -> Action begin code _span _str _len = do pushLexState code; lexToken @@ -580,6 +585,8 @@ notFollowedBy char _ _ _ (_,buf) = atEnd buf || currentChar buf /= char notFollowedBySymbol _ _ _ (_,buf) = atEnd buf || currentChar buf `notElem` "!#$%&*+./<=>?@\\^|-~" +atEOL _ _ _ (_,buf) = atEnd buf || currentChar buf == '\n' + ifExtension pred bits _ _ _ = pred bits {- @@ -608,16 +615,17 @@ nested_comment span _str _len = do Just (c,input) -> go n input c -> go n input - err input = do failLocMsgP (srcSpanStart span) (fst input) "unterminated `{-'" + err input = do failLocMsgP (srcSpanStart span) (fst input) + "unterminated `{-'" open_brace, close_brace :: Action -open_brace span _str _len = do +open_brace span _str _len = do ctx <- getContext setContext (NoLayout:ctx) - return (T span ITocurly) + return (L span ITocurly) close_brace span _str _len = do popContext - return (T span ITccurly) + return (L span ITccurly) -- We have to be careful not to count M. as a qualified name -- when is a keyword. We hack around this by catching @@ -635,7 +643,7 @@ check_qvarid span buf len = do _other -> return token where (mod,var) = splitQualName buf len - token = T span (ITqvarid (mod,var)) + token = L span (ITqvarid (mod,var)) try_again = do setInput (srcSpanStart span,buf) @@ -671,13 +679,13 @@ varid span buf len = case lookupUFM reservedWordsFM fs of Just (keyword,0) -> do maybe_layout keyword - return (T span keyword) + return (L span keyword) Just (keyword,exts) -> do b <- extension (\i -> exts .&. i /= 0) if b then do maybe_layout keyword - return (T span keyword) - else return (T span (ITvarid fs)) - _other -> return (T span (ITvarid fs)) + return (L span keyword) + else return (L span (ITvarid fs)) + _other -> return (L span (ITvarid fs)) where fs = lexemeToFastString buf len @@ -692,42 +700,36 @@ consym = sym ITconsym sym con span buf len = case lookupUFM reservedSymsFM fs of - Just (keyword,0) -> return (T span keyword) + Just (keyword,0) -> return (L span keyword) Just (keyword,exts) -> do b <- extension (\i -> exts .&. i /= 0) - if b then return (T span keyword) - else return (T span $! con fs) - _other -> return (T span $! con fs) + if b then return (L span keyword) + else return (L span $! con fs) + _other -> return (L span $! con fs) where fs = lexemeToFastString buf len tok_decimal span buf len - = return (T span (ITinteger $! parseInteger buf len 10 oct_or_dec)) + = return (L span (ITinteger $! parseInteger buf len 10 octDecDigit)) tok_octal span buf len - = return (T span (ITinteger $! parseInteger (stepOnBy 2 buf) (len-2) 8 oct_or_dec)) + = return (L span (ITinteger $! parseInteger (stepOnBy 2 buf) (len-2) 8 octDecDigit)) tok_hexadecimal span buf len - = return (T span (ITinteger $! parseInteger (stepOnBy 2 buf) (len-2) 16 hex)) + = return (L span (ITinteger $! parseInteger (stepOnBy 2 buf) (len-2) 16 hexDigit)) prim_decimal span buf len - = return (T span (ITprimint $! parseInteger buf (len-1) 10 oct_or_dec)) + = return (L span (ITprimint $! parseInteger buf (len-1) 10 octDecDigit)) prim_octal span buf len - = return (T span (ITprimint $! parseInteger (stepOnBy 2 buf) (len-3) 8 oct_or_dec)) + = return (L span (ITprimint $! parseInteger (stepOnBy 2 buf) (len-3) 8 octDecDigit)) prim_hexadecimal span buf len - = return (T span (ITprimint $! parseInteger (stepOnBy 2 buf) (len-3) 16 hex)) + = return (L span (ITprimint $! parseInteger (stepOnBy 2 buf) (len-3) 16 hexDigit)) -tok_float str = ITrational $! readRational__ str -prim_float str = ITprimfloat $! readRational__ str -prim_double str = ITprimdouble $! readRational__ str - -parseInteger :: StringBuffer -> Int -> Integer -> (Char->Int) -> Integer -parseInteger buf len radix to_int - = go 0 0 - where go i x | i == len = x - | otherwise = go (i+1) (x * radix + toInteger (to_int (lookAhead buf i))) +tok_float str = ITrational $! readRational str +prim_float str = ITprimfloat $! readRational str +prim_double str = ITprimdouble $! readRational str -- ----------------------------------------------------------------------------- -- Layout processing @@ -735,17 +737,17 @@ parseInteger buf len radix to_int -- we're at the first token on a line, insert layout tokens if necessary do_bol :: Action do_bol span _str _len = do - pos <- getOffside (srcSpanEndCol span) + pos <- getOffside (srcSpanEnd span) case pos of LT -> do --trace "layout: inserting '}'" $ do popContext -- do NOT pop the lex state, we might have a ';' to insert - return (T span ITvccurly) + return (L span ITvccurly) EQ -> do --trace "layout: inserting ';'" $ do popLexState - return (T span ITsemi) + return (L span ITsemi) GT -> do popLexState lexToken @@ -780,30 +782,30 @@ new_layout_context strict span _buf _len = do -- token is indented to the left of the previous context. -- we must generate a {} sequence now. pushLexState layout_left - return (T span ITvocurly) + return (L span ITvocurly) other -> do setContext (Layout offset : ctx) - return (T span ITvocurly) + return (L span ITvocurly) do_layout_left span _buf _len = do popLexState pushLexState bol -- we must be at the start of a line - return (T span ITvccurly) + return (L span ITvccurly) -- ----------------------------------------------------------------------------- -- LINE pragmas -set_line :: Int -> Action -set_line code span buf len = do - let line = parseInteger buf len 10 oct_or_dec +setLine :: Int -> Action +setLine code span buf len = do + let line = parseInteger buf len 10 octDecDigit setSrcLoc (mkSrcLoc (srcSpanFile span) (fromIntegral line - 1) 0) -- subtract one: the line number refers to the *following* line popLexState pushLexState code lexToken -set_file :: Int -> Action -set_file code span buf len = do +setFile :: Int -> Action +setFile code span buf len = do let file = lexemeToFastString (stepOn buf) (len-2) setSrcLoc (mkSrcLoc file (srcSpanEndLine span) (srcSpanEndCol span)) popLexState @@ -819,9 +821,9 @@ lex_string_tok :: Action lex_string_tok span buf len = do tok <- lex_string "" end <- getSrcLoc - return (T (mkSrcSpan (srcSpanStart span) end) tok) + return (L (mkSrcSpan (srcSpanStart span) end) tok) -lex_string :: String -> P Token__ +lex_string :: String -> P Token lex_string s = do i <- getInput case alexGetChar i of @@ -882,7 +884,7 @@ lex_char_tok span buf len = do -- We've seen ' th_exts <- extension thEnabled if th_exts then do setInput i2 - return (T (mkSrcSpan loc end2) ITtyQuote) + return (L (mkSrcSpan loc end2) ITtyQuote) else lit_error Just ('\\', i2@(end2,_)) -> do -- We've seen 'backslash @@ -905,24 +907,23 @@ lex_char_tok span buf len = do -- We've seen ' _other -> do -- We've seen 'x not followed by quote -- If TH is on, just parse the quote only th_exts <- extension thEnabled - if th_exts then return (T (mkSrcSpan loc (fst i1)) ITvarQuote) + if th_exts then return (L (mkSrcSpan loc (fst i1)) ITvarQuote) else lit_error -finish_char_tok :: SrcLoc -> Char -> P Token +finish_char_tok :: SrcLoc -> Char -> P (Located Token) finish_char_tok loc ch -- We've already seen the closing quote -- Just need to check for trailing # = do glaexts <- extension glaExtsEnabled + i@(end,_) <- getInput if glaexts then do - i@(end,_) <- getInput case alexGetChar i of Just ('#',i@(end,_)) -> do setInput i - return (T (mkSrcSpan loc end) (ITprimchar ch)) + return (L (mkSrcSpan loc end) (ITprimchar ch)) _other -> - return (T (mkSrcSpan loc end) (ITchar ch)) + return (L (mkSrcSpan loc end) (ITchar ch)) else do - end <- getSrcLoc - return (T (mkSrcSpan loc end) (ITchar ch)) + return (L (mkSrcSpan loc end) (ITchar ch)) lex_char :: P Char lex_char = do @@ -951,9 +952,9 @@ lex_escape = do then return (chr (ord c - ord '@')) else lit_error - 'x' -> readNum is_hexdigit 16 hex - 'o' -> readNum is_octdigit 8 oct_or_dec - x | is_digit x -> readNum2 is_digit 10 oct_or_dec (oct_or_dec x) + 'x' -> readNum is_hexdigit 16 hexDigit + 'o' -> readNum is_octdigit 8 octDecDigit + x | is_digit x -> readNum2 is_digit 10 octDecDigit (octDecDigit x) c1 -> do i <- getInput @@ -994,22 +995,6 @@ readNum2 is_digit base conv i = do then return (chr i) else lit_error -is_hexdigit c - = is_digit c - || (c >= 'a' && c <= 'f') - || (c >= 'A' && c <= 'F') - -hex c | is_digit c = ord c - ord '0' - | otherwise = ord (to_lower c) - ord 'a' + 10 - -oct_or_dec c = ord c - ord '0' - -is_octdigit c = c >= '0' && c <= '7' - -to_lower c - | c >= 'A' && c <= 'Z' = chr (ord c - (ord 'A' - ord 'a')) - | otherwise = c - silly_escape_chars = [ ("NUL", '\NUL'), ("SOH", '\SOH'), @@ -1057,54 +1042,6 @@ getCharOrFail = do Just (c,i) -> do setInput i; return c -- ----------------------------------------------------------------------------- --- Floats - -readRational :: ReadS Rational -- NB: doesn't handle leading "-" -readRational r = do - (n,d,s) <- readFix r - (k,t) <- readExp s - return ((n%1)*10^^(k-d), t) - where - readFix r = do - (ds,s) <- lexDecDigits r - (ds',t) <- lexDotDigits s - return (read (ds++ds'), length ds', t) - - readExp (e:s) | e `elem` "eE" = readExp' s - readExp s = return (0,s) - - readExp' ('+':s) = readDec s - readExp' ('-':s) = do - (k,t) <- readDec s - return (-k,t) - readExp' s = readDec s - - readDec s = do - (ds,r) <- nonnull isDigit s - return (foldl1 (\n d -> n * 10 + d) [ ord d - ord '0' | d <- ds ], - r) - - lexDecDigits = nonnull isDigit - - lexDotDigits ('.':s) = return (span isDigit s) - lexDotDigits s = return ("",s) - - nonnull p s = do (cs@(_:_),t) <- return (span p s) - return (cs,t) - -readRational__ :: String -> Rational -- NB: *does* handle a leading "-" -readRational__ top_s - = case top_s of - '-' : xs -> - (read_me xs) - xs -> read_me xs - where - read_me s - = case (do { (x,"") <- readRational s ; return x }) of - [x] -> x - [] -> error ("readRational__: no parse:" ++ top_s) - _ -> error ("readRational__: ambiguous parse:" ++ top_s) - --- ----------------------------------------------------------------------------- -- The Parse Monad data LayoutContext @@ -1114,26 +1051,25 @@ data LayoutContext data ParseResult a = POk PState a | PFailed - SrcSpan -- The spam the error. Might be used in environments - -- which can show this span, e.g. by highlighting it. + SrcSpan -- The start and end of the text span related to + -- the error. Might be used in environments which can + -- show this span, e.g. by highlighting it. Message -- The error message -showPFailed span err = hcat [ppr span, text ": ", err] - data PState = PState { buffer :: StringBuffer, - last_span :: SrcSpan, -- span of previous token - last_len :: !Int, + last_loc :: SrcSpan, -- pos of previous token + last_len :: !Int, -- len of previous token loc :: SrcLoc, -- current loc (end of prev token + 1) extsBitmap :: !Int, -- bitmap that determines permitted extensions context :: [LayoutContext], lex_state :: [Int] } - -- last_span is used when generating error messages, - -- and in pushCurrentContext only. - -- last_len is used when generating error messages, and is - -- needed because we need to back up the buffer pointer by that - -- number of characters for outputing the token in the error message. + -- last_loc and last_len are used when generating error messages, + -- and in pushCurrentContext only. Sigh, if only Happy passed the + -- current token to happyError, we could at least get rid of last_len. + -- Getting rid of last_loc would require finding another way to + -- implement pushCurrentContext (which is only called from one place). newtype P a = P { unP :: PState -> ParseResult a } @@ -1152,14 +1088,17 @@ thenP :: P a -> (a -> P b) -> P b PFailed span err -> PFailed span err failP :: String -> P a -failP msg = P $ \s -> PFailed (last_span s) (text msg) +failP msg = P $ \s -> PFailed (last_loc s) (text msg) failMsgP :: String -> P a -failMsgP msg = P $ \s -> PFailed (last_span s) (text msg) +failMsgP msg = P $ \s -> PFailed (last_loc s) (text msg) failLocMsgP :: SrcLoc -> SrcLoc -> String -> P a failLocMsgP loc1 loc2 str = P $ \s -> PFailed (mkSrcSpan loc1 loc2) (text str) +failSpanMsgP :: SrcSpan -> String -> P a +failSpanMsgP span msg = P $ \s -> PFailed span (text msg) + extension :: (Int -> Bool) -> P Bool extension p = P $ \s -> POk s (p $! extsBitmap s) @@ -1169,19 +1108,11 @@ getExts = P $ \s -> POk s (extsBitmap s) setSrcLoc :: SrcLoc -> P () setSrcLoc new_loc = P $ \s -> POk s{loc=new_loc} () --- tmp, for supporting stuff in RdrHsSyn. The scope better not include --- any calls to the lexer, because it assumes things about the SrcLoc. -setSrcLocFor :: SrcLoc -> P a -> P a -setSrcLocFor new_loc scope = P $ \s@PState{ loc = old_loc } -> - case unP scope s{loc=new_loc} of - PFailed span msg -> PFailed span msg - POk _ r -> POk s r - getSrcLoc :: P SrcLoc getSrcLoc = P $ \s@(PState{ loc=loc }) -> POk s loc setLastToken :: SrcSpan -> Int -> P () -setLastToken span len = P $ \s -> POk s{ last_span=span, last_len=len } () +setLastToken loc len = P $ \s -> POk s{ last_loc=loc, last_len=len } () type AlexInput = (SrcLoc,StringBuffer) @@ -1237,7 +1168,7 @@ mkPState :: StringBuffer -> SrcLoc -> DynFlags -> PState mkPState buf loc flags = PState { buffer = buf, - last_span = mkSrcSpan loc loc, + last_loc = mkSrcSpan loc loc, last_len = 0, loc = loc, extsBitmap = fromIntegral bitmap, @@ -1265,24 +1196,24 @@ setContext ctx = P $ \s -> POk s{context=ctx} () popContext :: P () popContext = P $ \ s@(PState{ buffer = buf, context = ctx, - loc = loc, last_len = len, last_span = last_span }) -> + loc = loc, last_len = len, last_loc = last_loc }) -> case ctx of (_:tl) -> POk s{ context = tl } () - [] -> PFailed last_span (srcParseErr buf len) + [] -> PFailed last_loc (srcParseErr buf len) -- Push a new layout context at the indentation of the last token read. -- This is only used at the outer level of a module when the 'module' -- keyword is missing. pushCurrentContext :: P () -pushCurrentContext = P $ \ s@PState{ last_span=span, context=ctx } -> - POk s{ context = Layout (srcSpanStartCol span) : ctx} () +pushCurrentContext = P $ \ s@PState{ last_loc=loc, context=ctx } -> + POk s{ context = Layout (srcSpanStartCol loc) : ctx} () -getOffside :: Int -> P Ordering -getOffside col = P $ \s@PState{context=stk} -> +getOffside :: SrcLoc -> P Ordering +getOffside loc = P $ \s@PState{context=stk} -> let ord = case stk of - (Layout n:_) -> compare col n + (Layout n:_) -> compare (srcLocCol loc) n _ -> GT - in POk s $! ord + in POk s ord -- --------------------------------------------------------------------------- -- Construct a parse error @@ -1304,8 +1235,8 @@ srcParseErr buf len -- detected during parsing. srcParseFail :: P a srcParseFail = P $ \PState{ buffer = buf, last_len = len, - last_span = last_span, loc = loc } -> - PFailed last_span (srcParseErr buf len) + last_loc = last_loc } -> + PFailed last_loc (srcParseErr buf len) -- A lexical error is reported at a particular position in the source file, -- not over a token range. TODO: this is slightly wrong, because we record @@ -1314,19 +1245,20 @@ srcParseFail = P $ \PState{ buffer = buf, last_len = len, lexError :: String -> P a lexError str = do loc <- getSrcLoc - failLocMsgP loc loc str + i@(end,_) <- getInput + failLocMsgP loc end str -- ----------------------------------------------------------------------------- -- This is the top-level function: called from the parser each time a -- new token is to be read from the input. -lexer :: (Token -> P a) -> P a +lexer :: (Located Token -> P a) -> P a lexer cont = do - tok@(T _ tok__) <- lexToken + tok@(L _ tok__) <- lexToken --trace ("token: " ++ show tok__) $ do cont tok -lexToken :: P Token +lexToken :: P (Located Token) lexToken = do inp@(loc1,buf) <- getInput sc <- getLexState @@ -1334,7 +1266,7 @@ lexToken = do case alexScanUser exts inp sc of AlexEOF -> do let span = mkSrcSpan loc1 loc1 setLastToken span 0 - return (T span ITeof) + return (L span ITeof) AlexError (loc2,_) -> do failLocMsgP loc1 loc2 "lexical error" AlexSkip inp2 _ -> do setInput inp2 @@ -1342,6 +1274,6 @@ lexToken = do AlexToken inp2@(end,buf2) len t -> do setInput inp2 let span = mkSrcSpan loc1 end - (setLastToken $! span) $! len + span `seq` setLastToken span len t span buf len }