1 {-# OPTIONS -fno-warn-incomplete-patterns #-}
2 -- The above warning supression flag is a temporary kludge.
3 -- While working on this module you are encouraged to remove it and fix
4 -- any warnings in the module. See
5 -- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
8 -----------------------------------------------------------------------------
10 -- Parsing the top of a Haskell source file to get its module name,
11 -- imports and options.
13 -- (c) Simon Marlow 2005
16 -----------------------------------------------------------------------------
18 module HeaderInfo ( getImports
19 , getOptionsFromFile, getOptions
20 , optionsErrorMsgs ) where
22 #include "HsVersions.h"
24 import Parser ( parseHeader )
27 import HsSyn ( ImportDecl(..), HsModule(..) )
28 import Module ( ModuleName, moduleName )
29 import PrelNames ( gHC_PRIM, mAIN_NAME )
30 import StringBuffer ( StringBuffer(..), hGetStringBufferBlock
31 , appendStringBuffers )
40 import Bag ( emptyBag, listToBag )
42 import Control.Exception
48 #if !defined(__GLASGOW_HASKELL__) || __GLASGOW_HASKELL__ >= 601
49 -- already imported above
50 --import System.IO ( openBinaryFile )
52 import IOExts ( openFileEx, IOModeEx(..) )
55 #if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ < 601
56 openBinaryFile fp mode = openFileEx fp (BinaryMode mode)
59 getImports :: DynFlags -> StringBuffer -> FilePath -> FilePath
60 -> IO ([Located ModuleName], [Located ModuleName], Located ModuleName)
61 getImports dflags buf filename source_filename = do
62 let loc = mkSrcLoc (mkFastString filename) 1 0
63 case unP parseHeader (mkPState buf loc dflags) of
64 PFailed span err -> parseError span err
65 POk pst rdr_module -> do
66 let ms = getMessages pst
67 printErrorsAndWarnings dflags ms
68 when (errorsFound dflags ms) $ exitWith (ExitFailure 1)
70 L _ (HsModule mb_mod _ imps _ _ _ _) ->
72 main_loc = mkSrcLoc (mkFastString source_filename) 1 0
73 mod = mb_mod `orElse` L (srcLocSpan main_loc) mAIN_NAME
74 (src_idecls, ord_idecls) = partition isSourceIdecl (map unLoc imps)
75 source_imps = map getImpMod src_idecls
76 ordinary_imps = filter ((/= moduleName gHC_PRIM) . unLoc)
77 (map getImpMod ord_idecls)
78 -- GHC.Prim doesn't exist physically, so don't go looking for it.
80 return (source_imps, ordinary_imps, mod)
82 parseError :: SrcSpan -> Message -> a
83 parseError span err = throwDyn $ mkPlainErrMsg span err
85 isSourceIdecl :: ImportDecl name -> Bool
86 isSourceIdecl (ImportDecl _ s _ _ _) = s
88 getImpMod :: ImportDecl name -> Located ModuleName
89 getImpMod (ImportDecl located_mod _ _ _ _) = located_mod
91 --------------------------------------------------------------
93 --------------------------------------------------------------
96 getOptionsFromFile :: DynFlags
97 -> FilePath -- input file
98 -> IO [Located String] -- options, if any
99 getOptionsFromFile dflags filename
100 = Control.Exception.bracket
101 (openBinaryFile filename ReadMode)
104 do buf <- hGetStringBufferBlock handle blockSize
106 where blockSize = 1024
108 | len buf == 0 = return []
110 = case getOptions' dflags buf filename of
111 (Nothing, opts) -> return opts
112 (Just buf', opts) -> do nextBlock <- hGetStringBufferBlock handle blockSize
113 newBuf <- appendStringBuffers buf' nextBlock
114 if len newBuf == len buf
116 else do opts' <- loop handle newBuf
119 getOptions :: DynFlags -> StringBuffer -> FilePath -> [Located String]
120 getOptions dflags buf filename
121 = case getOptions' dflags buf filename of
124 -- The token parser is written manually because Happy can't
125 -- return a partial result when it encounters a lexer error.
126 -- We want to extract options before the buffer is passed through
127 -- CPP, so we can't use the same trick as 'getImports'.
128 getOptions' :: DynFlags
129 -> StringBuffer -- Input buffer
130 -> FilePath -- Source file. Used for msgs only.
131 -> ( Maybe StringBuffer -- Just => we can use more input
132 , [Located String] -- Options.
134 getOptions' dflags buf filename
135 = parseToks (lexAll (pragState dflags buf loc))
136 where loc = mkSrcLoc (mkFastString filename) 1 0
138 getToken (_buf,L _loc tok) = tok
139 getLoc (_buf,L loc _tok) = loc
140 getBuf (buf,_tok) = buf
141 combine opts (flag, opts') = (flag, opts++opts')
142 add opt (flag, opts) = (flag, opt:opts)
144 parseToks (open:close:xs)
145 | IToptions_prag str <- getToken open
146 , ITclose_prag <- getToken close
147 = map (L (getLoc open)) (words str) `combine`
149 parseToks (open:close:xs)
150 | ITinclude_prag str <- getToken open
151 , ITclose_prag <- getToken close
152 = map (L (getLoc open)) ["-#include",removeSpaces str] `combine`
154 parseToks (open:close:xs)
155 | ITdocOptions str <- getToken open
156 , ITclose_prag <- getToken close
157 = map (L (getLoc open)) ["-haddock-opts", removeSpaces str]
158 `combine` parseToks xs
160 | ITdocOptionsOld str <- getToken open
161 = map (L (getLoc open)) ["-haddock-opts", removeSpaces str]
162 `combine` parseToks xs
164 | ITlanguage_prag <- getToken open
166 -- The last token before EOF could have been truncated.
167 -- We ignore it to be on the safe side.
169 | ITeof <- getToken eof
170 = (Just (getBuf tok),[])
172 | ITeof <- getToken eof
173 = (Just (getBuf eof),[])
174 parseToks _ = (Nothing,[])
175 parseLanguage ((_buf,L loc (ITconid fs)):rest)
176 = checkExtension (L loc fs) `add`
178 (_,L _loc ITcomma):more -> parseLanguage more
179 (_,L _loc ITclose_prag):more -> parseToks more
180 (_,L loc _):_ -> languagePragParseError loc
181 parseLanguage (tok:_)
182 = languagePragParseError (getLoc tok)
183 lexToken t = return t
184 lexAll state = case unP (lexer lexToken) state of
185 POk _ t@(L _ ITeof) -> [(buffer state,t)]
186 POk state' t -> (buffer state,t):lexAll state'
187 _ -> [(buffer state,L (last_loc state) ITeof)]
189 checkExtension :: Located FastString -> Located String
190 checkExtension (L l ext)
191 -- Checks if a given extension is valid, and if so returns
192 -- its corresponding flag. Otherwise it throws an exception.
193 = let ext' = unpackFS ext in
194 if ext' `elem` supportedLanguages
195 || ext' `elem` (map ("No"++) supportedLanguages)
196 then L l ("-X"++ext')
197 else unsupportedExtnError l ext'
199 languagePragParseError :: SrcSpan -> a
200 languagePragParseError loc =
202 (showSDoc (mkLocMessage loc (
203 text "cannot parse LANGUAGE pragma: comma-separated list expected")))
205 unsupportedExtnError :: SrcSpan -> String -> a
206 unsupportedExtnError loc unsup =
207 pgmError (showSDoc (mkLocMessage loc (
208 text "unsupported extension: " <>
212 optionsErrorMsgs :: [String] -> [Located String] -> FilePath -> Messages
213 optionsErrorMsgs unhandled_flags flags_lines _filename
214 = (emptyBag, listToBag (map mkMsg unhandled_flags_lines))
215 where unhandled_flags_lines = [ L l f | f <- unhandled_flags,
216 L l f' <- flags_lines, f == f' ]
217 mkMsg (L flagSpan flag) =
218 ErrUtils.mkPlainErrMsg flagSpan $
219 text "unknown flag in {-# OPTIONS #-} pragma:" <+> text flag