lots of portability changes (#1405)
[ghc.git] / compiler / main / HeaderInfo.hs
1 {-# OPTIONS -w #-}
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
6 -- for details
7
8 -----------------------------------------------------------------------------
9 --
10 -- Parsing the top of a Haskell source file to get its module name,
11 -- imports and options.
12 --
13 -- (c) Simon Marlow 2005
14 -- (c) Lemmih 2006
15 --
16 -----------------------------------------------------------------------------
17
18 module HeaderInfo ( getImports
19 , getOptionsFromFile, getOptions
20 , optionsErrorMsgs ) where
21
22 #include "HsVersions.h"
23
24 import Parser ( parseHeader )
25 import Lexer
26 import FastString
27 import HsSyn ( ImportDecl(..), HsModule(..) )
28 import Module ( ModuleName, moduleName )
29 import PrelNames ( gHC_PRIM, mAIN_NAME )
30 import StringBuffer ( StringBuffer(..), hGetStringBuffer, hGetStringBufferBlock
31 , appendStringBuffers )
32 import Config
33 import SrcLoc
34 import DynFlags
35 import ErrUtils
36 import Util
37 import Outputable
38 import Pretty ()
39 import Panic
40 import Maybes
41 import Bag ( emptyBag, listToBag )
42
43 import Control.Exception
44 import Control.Monad
45 import System.Exit
46 import System.IO
47 import Data.List
48
49 #if !defined(__GLASGOW_HASKELL__) || __GLASGOW_HASKELL__ >= 601
50 import System.IO ( openBinaryFile )
51 #else
52 import IOExts ( openFileEx, IOModeEx(..) )
53 #endif
54
55 #if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ < 601
56 openBinaryFile fp mode = openFileEx fp (BinaryMode mode)
57 #endif
58
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)
69 case rdr_module of
70 L _ (HsModule mb_mod _ imps _ _ _ _) ->
71 let
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.
79 in
80 return (source_imps, ordinary_imps, mod)
81
82 parseError span err = throwDyn $ mkPlainErrMsg span err
83
84 isSourceIdecl (ImportDecl _ s _ _ _) = s
85
86 getImpMod (ImportDecl located_mod _ _ _ _) = located_mod
87
88 --------------------------------------------------------------
89 -- Get options
90 --------------------------------------------------------------
91
92
93 getOptionsFromFile :: FilePath -- input file
94 -> IO [Located String] -- options, if any
95 getOptionsFromFile filename
96 = Control.Exception.bracket
97 (openBinaryFile filename ReadMode)
98 (hClose)
99 (\handle ->
100 do buf <- hGetStringBufferBlock handle blockSize
101 loop handle buf)
102 where blockSize = 1024
103 loop handle buf
104 | len buf == 0 = return []
105 | otherwise
106 = case getOptions' buf filename of
107 (Nothing, opts) -> return opts
108 (Just buf', opts) -> do nextBlock <- hGetStringBufferBlock handle blockSize
109 newBuf <- appendStringBuffers buf' nextBlock
110 if len newBuf == len buf
111 then return opts
112 else do opts' <- loop handle newBuf
113 return (opts++opts')
114
115 getOptions :: StringBuffer -> FilePath -> [Located String]
116 getOptions buf filename
117 = case getOptions' buf filename of
118 (_,opts) -> opts
119
120 -- The token parser is written manually because Happy can't
121 -- return a partial result when it encounters a lexer error.
122 -- We want to extract options before the buffer is passed through
123 -- CPP, so we can't use the same trick as 'getImports'.
124 getOptions' :: StringBuffer -- Input buffer
125 -> FilePath -- Source file. Used for msgs only.
126 -> ( Maybe StringBuffer -- Just => we can use more input
127 , [Located String] -- Options.
128 )
129 getOptions' buf filename
130 = parseToks (lexAll (pragState buf loc))
131 where loc = mkSrcLoc (mkFastString filename) 1 0
132
133 getToken (buf,L _loc tok) = tok
134 getLoc (buf,L loc _tok) = loc
135 getBuf (buf,_tok) = buf
136 combine opts (flag, opts') = (flag, opts++opts')
137 add opt (flag, opts) = (flag, opt:opts)
138
139 parseToks (open:close:xs)
140 | IToptions_prag str <- getToken open
141 , ITclose_prag <- getToken close
142 = map (L (getLoc open)) (words str) `combine`
143 parseToks xs
144 parseToks (open:close:xs)
145 | ITinclude_prag str <- getToken open
146 , ITclose_prag <- getToken close
147 = map (L (getLoc open)) ["-#include",removeSpaces str] `combine`
148 parseToks xs
149 parseToks (open:close:xs)
150 | ITdocOptions str <- getToken open
151 , ITclose_prag <- getToken close
152 = map (L (getLoc open)) ["-haddock-opts", removeSpaces str]
153 `combine` parseToks xs
154 parseToks (open:xs)
155 | ITdocOptionsOld str <- getToken open
156 = map (L (getLoc open)) ["-haddock-opts", removeSpaces str]
157 `combine` parseToks xs
158 parseToks (open:xs)
159 | ITlanguage_prag <- getToken open
160 = parseLanguage xs
161 -- The last token before EOF could have been truncated.
162 -- We ignore it to be on the safe side.
163 parseToks [tok,eof]
164 | ITeof <- getToken eof
165 = (Just (getBuf tok),[])
166 parseToks (eof:_)
167 | ITeof <- getToken eof
168 = (Just (getBuf eof),[])
169 parseToks _ = (Nothing,[])
170 parseLanguage ((_buf,L loc (ITconid fs)):rest)
171 = checkExtension (L loc fs) `add`
172 case rest of
173 (_,L loc ITcomma):more -> parseLanguage more
174 (_,L loc ITclose_prag):more -> parseToks more
175 (_,L loc _):_ -> languagePragParseError loc
176 parseLanguage (tok:_)
177 = languagePragParseError (getLoc tok)
178 lexToken t = return t
179 lexAll state = case unP (lexer lexToken) state of
180 POk state' t@(L _ ITeof) -> [(buffer state,t)]
181 POk state' t -> (buffer state,t):lexAll state'
182 _ -> [(buffer state,L (last_loc state) ITeof)]
183
184 checkExtension :: Located FastString -> Located String
185 checkExtension (L l ext)
186 -- Checks if a given extension is valid, and if so returns
187 -- its corresponding flag. Otherwise it throws an exception.
188 = let ext' = unpackFS ext in
189 if ext' `elem` supportedLanguages
190 || ext' `elem` (map ("No"++) supportedLanguages)
191 then L l ("-X"++ext')
192 else unsupportedExtnError l ext'
193
194 languagePragParseError loc =
195 pgmError (showSDoc (mkLocMessage loc (
196 text "cannot parse LANGUAGE pragma")))
197
198 unsupportedExtnError loc unsup =
199 pgmError (showSDoc (mkLocMessage loc (
200 text "unsupported extension: " <>
201 text unsup)))
202
203
204 optionsErrorMsgs :: [String] -> [Located String] -> FilePath -> Messages
205 optionsErrorMsgs unhandled_flags flags_lines filename
206 = (emptyBag, listToBag (map mkMsg unhandled_flags_lines))
207 where unhandled_flags_lines = [ L l f | f <- unhandled_flags,
208 L l f' <- flags_lines, f == f' ]
209 mkMsg (L flagSpan flag) =
210 ErrUtils.mkPlainErrMsg flagSpan $
211 text "unknown flag in {-# OPTIONS #-} pragma:" <+> text flag
212