----------------------------------------------------------------------------- The main driver. (c) 1993-2003 Andy Gill, Simon Marlow GLR amendments (c) University of Durham, Ben Medlock 2001 ----------------------------------------------------------------------------- > module Main (main) where Path settings auto-generated by Cabal: > import Paths_happy > import Happy.Grammar > import Happy.Frontend > import Happy.Frontend.AbsSyn > import Happy.Frontend.Mangler > import Happy.Frontend.PrettyGrammar > import Happy.Backend.LALR > import Happy.Backend.LALR.ProduceCode (produceParser) > import Happy.Backend.GLR > import Happy.Backend.GLR.ProduceCode > import Happy.Tabular > import Happy.Tabular.Info (genInfoFile) > import System.Console.GetOpt > import Control.Monad ( liftM, when, unless ) > import System.Environment > import System.Exit (exitWith, ExitCode(..)) > import Data.Char > import System.IO > import Data.List( isSuffixOf ) > import Data.Version ( showVersion ) > main :: IO () > main = do Read and parse the CLI arguments. > args <- getArgs > main2 args > main2 :: [String] -> IO () > main2 args = Read and parse the CLI arguments. > case getOpt Permute argInfo (constArgs ++ args) of > (cli,_,[]) | DumpVersion `elem` cli -> > bye copyright > (cli,_,[]) | DumpHelp `elem` cli -> do > prog <- getProgramName > bye (usageInfo (usageHeader prog) argInfo) > (cli,[fl_name],[]) -> > runParserGen cli fl_name > (_,_,errors) -> do > prog <- getProgramName > die (concat errors ++ > usageInfo (usageHeader prog) argInfo) > where > runParserGen cli fl_name = do If no -g flag has been passed, show a warning. > unless (OptGhcTarget `elem` cli) $ > hPutStrLn stderr "Warning: With happy 2.0, the --ghc flag has become non-optional. To suppress this warning, pass the --ghc flag." Open the file. > fl <- readFile fl_name > (name, file) <- case fileNameAndType fl_name of > Nothing -> die ("`" ++ fl_name ++ "' does not end in `.y' or `.ly'\n") > Just (name, Y) -> return (name, fl) > Just (name, LY) -> return (name, deLitify fl) Parse, using bootstrapping parser. > (BookendedAbsSyn hd abssyn tl) <- case parseYFileContents file of > Left err -> die (fl_name ++ ':' : err) > Right bas -> return bas Mangle the syntax into something useful. > (g, common_options) <- case {-# SCC "Mangler" #-} mangler fl_name abssyn of > Left s -> die (unlines s ++ "\n") > Right gd -> return gd > optPrint cli DumpMangle $ putStr $ show g > let select_reductions | OptGLR `elem` cli = select_all_reductions > | otherwise = select_first_reduction > let tables = genTables select_reductions g > sets = lr0items tables > lainfo = (la_prop tables, la_spont tables) > la = lookaheads tables > goto = gotoTable tables > action = actionTable tables > (conflictArray,(sr,rr)) = conflicts tables Debug output > optPrint cli DumpLR0 $ putStr $ show sets > optPrint cli DumpAction $ putStr $ show action > optPrint cli DumpGoto $ putStr $ show goto > optPrint cli DumpLA $ putStr $ show lainfo > optPrint cli DumpLA $ putStr $ show la Report any unused rules and terminals > let (unused_rules, unused_terminals) = redundancies tables > when (not (null unused_rules)) > (hPutStrLn stderr ("unused rules: " ++ show (length unused_rules))) > when (not (null unused_terminals)) > (hPutStrLn stderr ("unused terminals: " ++ show (length unused_terminals))) Print out the info file. > info_filename <- getInfoFileName name cli > let info = genInfoFile > (map fst sets) > g > action > goto > (token_specs g) > conflictArray > fl_name > unused_rules > unused_terminals > version > case info_filename of > Just s -> do > writeFile s info > hPutStrLn stderr ("Grammar info written to: " ++ s) > Nothing -> return () Pretty print the AbsSyn. > pretty_filename <- getPrettyFileName name cli > case pretty_filename of > Just s -> do > let out = render (ppAbsSyn abssyn) > writeFile s out > hPutStrLn stderr ("Production rules written to: " ++ s) > Nothing -> return () Report any conflicts in the grammar. > case expect common_options of > Just n | n == sr && rr == 0 -> return () > Just _ | rr > 0 -> > die ("The grammar has reduce/reduce conflicts.\n" ++ > "This is not allowed when an expect directive is given\n") > Just _ -> > die ("The grammar has " ++ show sr ++ > " shift/reduce conflicts.\n" ++ > "This is different from the number given in the " ++ > "expect directive\n") > _ -> do > (if sr /= 0 > then hPutStrLn stderr ("shift/reduce conflicts: " ++ show sr) > else return ()) > (if rr /= 0 > then hPutStrLn stderr ("reduce/reduce conflicts: " ++ show rr) > else return ()) Now, let's get on with generating the parser. Firstly, find out what kind of code we should generate, and where it should go: > outfilename <- getOutputFileName fl_name cli > opt_coerce <- getCoerce cli > opt_strict <- getStrict cli > opt_debug <- getDebug cli Add any special options or imports required by the parsing machinery. > let > header = Just $ > (case hd of Just s -> s; Nothing -> "") > ++ importsToInject opt_debug > if OptGLR `elem` cli %--------------------------------------- Branch off to GLR parser production > then do > let > glr_decode > | OptGLR_Decode `elem` cli = TreeDecode > | otherwise = LabelDecode > filtering > | OptGLR_Filter `elem` cli = UseFiltering > | otherwise = NoFiltering > ghc_exts = UseGhcExts > (importsToInject opt_debug) Unlike below, don't always pass CPP, because only one of the files needs it. > (langExtsToInject) > template' <- getTemplate glrBackendDataDir cli > let basename = takeWhile (/='.') outfilename > let tbls = (action,goto) > (parseName,_,_,_) <- case starts g of > [s] -> return s > s:_ -> do > putStrLn "GLR-Happy doesn't support multiple start points (yet)" > putStrLn "Defaulting to first start point." > return s > [] -> error "produceGLRParser: []" > base <- readFile (baseTemplate template') > lib <- readFile (libTemplate template') > let (dat, parser) = produceGLRParser > (base, lib) -- templates > basename -- basename of specified output file name > tbls -- action table (:: ActionTable) > -- goto table (:: GotoTable) > parseName > header -- header from grammar spec > tl -- trailer from grammar spec > (opt_debug, (glr_decode,filtering,ghc_exts)) > -- controls decoding code-gen > g -- grammar object > common_options -- grammar object > writeFile (basename ++ "Data.hs") dat > writeFile (basename ++ ".hs") parser %--------------------------------------- Resume normal (ie, non-GLR) processing > else do > template' <- getTemplate lalrBackendDataDir cli > let > template = template' ++ "/HappyTemplate.hs" Read in the template file for this target: > templ <- readFile template and generate the code. > magic_name <- getMagicName cli > let > outfile = produceParser > g > common_options > action > goto CPP is needed in all cases with unified template > ("CPP" : langExtsToInject) > header > tl > opt_coerce > opt_strict > defines' = defines opt_debug opt_coerce > (if outfilename == "-" then putStr else writeFile outfilename) > (magicFilter magic_name (outfile ++ defines' ++ templ)) Successfully Finished. ----------------------------------------------------------------------------- > getProgramName :: IO String > getProgramName = liftM (`withoutSuffix` ".bin") getProgName > where str' `withoutSuffix` suff > | suff `isSuffixOf` str' = take (length str' - length suff) str' > | otherwise = str' > bye :: String -> IO a > bye s = putStr s >> exitWith ExitSuccess > die :: String -> IO a > die s = hPutStr stderr s >> exitWith (ExitFailure 1) > dieHappy :: String -> IO a > dieHappy s = getProgramName >>= \prog -> die (prog ++ ": " ++ s) > optPrint :: [CLIFlags] -> CLIFlags -> IO () -> IO () > optPrint cli pass io = > when (elem pass cli) (putStr "\n---------------------\n" >> io) > constArgs :: [String] > constArgs = [] ------------------------------------------------------------------------------ The command line arguments. > data CLIFlags = > DumpMangle > | DumpLR0 > | DumpAction > | DumpGoto > | DumpLA > | DumpVersion > | DumpHelp > | OptInfoFile (Maybe String) > | OptPrettyFile (Maybe String) > | OptTemplate String > | OptMagicName String > | OptGhcTarget > | OptArrayTarget > | OptUseCoercions > | OptDebugParser > | OptStrict > | OptOutputFile String > | OptGLR > | OptGLR_Decode > | OptGLR_Filter > deriving Eq > argInfo :: [OptDescr CLIFlags] > argInfo = [ > Option ['o'] ["outfile"] (ReqArg OptOutputFile "FILE") > "write the output to FILE (default: file.hs)", > Option ['i'] ["info"] (OptArg OptInfoFile "FILE") > "put detailed grammar info in FILE", > Option ['p'] ["pretty"] (OptArg OptPrettyFile "FILE") > "pretty print the production rules to FILE", > Option ['t'] ["template"] (ReqArg OptTemplate "DIR") > "look in DIR for template files", > Option ['m'] ["magic-name"] (ReqArg OptMagicName "NAME") > "use NAME as the symbol prefix instead of \"happy\"", > Option ['s'] ["strict"] (NoArg OptStrict) > "evaluate semantic values strictly (experimental)", > Option ['g'] ["ghc"] (NoArg OptGhcTarget) > "use GHC extensions", > Option ['c'] ["coerce"] (NoArg OptUseCoercions) > "use type coercions (only available with -g)", > Option ['a'] ["array"] (NoArg OptArrayTarget) > "generate an array-based parser", > Option ['d'] ["debug"] (NoArg OptDebugParser) > "produce a debugging parser (only with -a)", > Option ['l'] ["glr"] (NoArg OptGLR) > "Generate a GLR parser for ambiguous grammars", > Option ['k'] ["decode"] (NoArg OptGLR_Decode) > "Generate simple decoding code for GLR result", > Option ['f'] ["filter"] (NoArg OptGLR_Filter) > "Filter the GLR parse forest with respect to semantic usage", > Option ['?'] ["help"] (NoArg DumpHelp) > "display this help and exit", > Option ['V','v'] ["version"] (NoArg DumpVersion) -- ToDo: -v is deprecated > "output version information and exit" Various debugging/dumping options... > , > Option [] ["ddump-mangle"] (NoArg DumpMangle) > "Dump mangled input", > Option [] ["ddump-lr0"] (NoArg DumpLR0) > "Dump LR0 item sets", > Option [] ["ddump-action"] (NoArg DumpAction) > "Dump action table", > Option [] ["ddump-goto"] (NoArg DumpGoto) > "Dump goto table", > Option [] ["ddump-lookaheads"] (NoArg DumpLA) > "Dump lookahead info" > ] ------------------------------------------------------------------------------ Extract various command-line options. > getOutputFileName :: String -> [CLIFlags] -> IO String > getOutputFileName ip_file cli > = case [ s | (OptOutputFile s) <- cli ] of > [] -> return (base ++ ".hs") > where (base, _ext) = break (== '.') ip_file > f:fs -> return (last (f:fs)) > getInfoFileName :: String -> [CLIFlags] -> IO (Maybe String) > getInfoFileName base cli > = case [ s | (OptInfoFile s) <- cli ] of > [] -> return Nothing > [f] -> case f of > Nothing -> return (Just (base ++ ".info")) > Just j -> return (Just j) > _many -> dieHappy "multiple --info/-i options\n" > getPrettyFileName :: String -> [CLIFlags] -> IO (Maybe String) > getPrettyFileName base cli > = case [ s | (OptPrettyFile s) <- cli ] of > [] -> return Nothing > [f] -> case f of > Nothing -> return (Just (base ++ ".grammar")) > Just j -> return (Just j) > _many -> dieHappy "multiple --pretty/-p options\n" > getTemplate :: IO String -> [CLIFlags] -> IO String > getTemplate def cli > = case [ s | (OptTemplate s) <- cli ] of > [] -> def > f:fs -> return (last (f:fs)) > getMagicName :: [CLIFlags] -> IO (Maybe String) > getMagicName cli > = case [ s | (OptMagicName s) <- cli ] of > [] -> return Nothing > f:fs -> return (Just (map toLower (last (f:fs)))) > getCoerce :: [CLIFlags] -> IO Bool > getCoerce cli = return (OptUseCoercions `elem` cli) > getStrict :: [CLIFlags] -> IO Bool > getStrict cli = return (OptStrict `elem` cli) > getDebug :: [CLIFlags] -> IO Bool > getDebug cli = return (OptDebugParser `elem` cli) ------------------------------------------------------------------------------ > copyright :: String > copyright = unlines [ > "Happy Version " ++ showVersion version ++ " Copyright (c) 1993-1996 Andy Gill, Simon Marlow (c) 1997-2005 Simon Marlow","", > "Happy is a Yacc for Haskell, and comes with ABSOLUTELY NO WARRANTY.", > "This program is free software; you can redistribute it and/or modify", > "it under the terms given in the file 'LICENSE' distributed with", > "the Happy sources."] > usageHeader :: String -> String > usageHeader prog = "Usage: " ++ prog ++ " [OPTION...] file\n" -----------------------------------------------------------------------------