116 lines
4.3 KiB
Haskell
116 lines
4.3 KiB
Haskell
{-
|
|
Tock: a compiler for parallel languages
|
|
Copyright (C) 2007 University of Kent
|
|
|
|
This program is free software; you can redistribute it and/or modify it
|
|
under the terms of the GNU General Public License as published by the
|
|
Free Software Foundation, either version 2 of the License, or (at your
|
|
option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful, but
|
|
WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License along
|
|
with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
-}
|
|
|
|
-- | Error handling and reporting.
|
|
module Errors (addPlainWarning, addWarning, checkJust, Die(..), dieInternal, dieIO, dieP, ErrorReport, showWarnings, Warn(..), WarningReport) where
|
|
|
|
import Control.Monad.Error
|
|
import Control.Monad.Trans
|
|
import Data.List
|
|
import System.IO
|
|
import System.IO.Error
|
|
|
|
import Metadata
|
|
|
|
type ErrorReport = (Maybe Meta, String)
|
|
|
|
instance Error ErrorReport where
|
|
strMsg s = (Nothing, s)
|
|
|
|
-- | Class of monads that can fail.
|
|
class Monad m => Die m where
|
|
dieReport :: ErrorReport -> m a
|
|
|
|
-- | Fail, giving a position and an error message.
|
|
dieP :: Die m => Meta -> String -> m a
|
|
dieP m s = dieReport (Just m,s)
|
|
|
|
type WarningReport = (Maybe Meta, String)
|
|
|
|
class Monad m => Warn m where
|
|
warnReport :: WarningReport -> m ()
|
|
|
|
--{{{ warnings
|
|
-- | Add a warning with no source position.
|
|
addPlainWarning :: Warn m => String -> m ()
|
|
addPlainWarning msg = warnReport (Nothing, msg)
|
|
|
|
-- | Add a warning.
|
|
addWarning :: Warn m => Meta -> String -> m ()
|
|
addWarning m s = warnReport (Just m, s)
|
|
--}}}
|
|
|
|
-- | Wrapper around error that gives nicer formatting, and prints out context
|
|
--
|
|
dieIO :: (Monad m, MonadIO m) => ErrorReport -> m a
|
|
dieIO (Just m@(Meta (Just fn) line column),s) = liftIO $
|
|
-- If we can't read the file successfully, still print our original error
|
|
-- rather than a "can't read file" error:
|
|
do fileContents <- catch (readFile fn) (\_ -> printError (show m ++ s))
|
|
let startingLine = max 1 (line - contextLines)
|
|
let lines = map replaceTabs $ getLines fileContents (startingLine) ((2 * contextLines) + 1)
|
|
putStrLn $ fn ++ ":"
|
|
printLines startingLine (take (line - startingLine + 1) lines)
|
|
putStr "Here"
|
|
replicateM_ column (putChar '-') -- column is unit-based, but we want an extra dash anyway
|
|
putStrLn "^"
|
|
printLines (line + 1) (drop (line - startingLine + 1) lines)
|
|
putStrLn ""
|
|
printError $ (show m) ++ " " ++ s
|
|
where
|
|
contextLines :: Int
|
|
contextLines = 5
|
|
-- start is unit-based, so we need to convert to zero-based
|
|
getLines :: String -> Int -> Int -> [String]
|
|
getLines all start total = take total (drop (start - 1) (lines all))
|
|
printLines :: Int -> [String] -> IO ()
|
|
printLines n lines = mapM_ (\(n,s) -> (putStrLn . ((++) (justify5 n) )) s) (zip [n..] lines)
|
|
--Makes sure line number and colon are exactly 5 characters long:
|
|
justify5 :: Int -> String
|
|
justify5 num = if n <= 4 then s ++ ":" ++ (replicate (4 - n) ' ') else "x" ++ (drop (n - 3) s) ++ ":"
|
|
where
|
|
s = show num
|
|
n = length s
|
|
-- Replace tabs with eight spaces, to match alex:
|
|
replaceTabs :: String -> String
|
|
replaceTabs [] = []
|
|
replaceTabs ('\t':ss) = (replicate 8 ' ') ++ replaceTabs ss
|
|
replaceTabs (s:ss) = (s : replaceTabs ss)
|
|
|
|
dieIO (_,s) = printError s
|
|
|
|
printError :: String -> a
|
|
printError s = error $ "Error: " ++ s ++ "\n"
|
|
|
|
-- | Print out a list of warnings
|
|
showWarnings :: MonadIO m => [WarningReport] -> m ()
|
|
showWarnings = mapM_ printWarning
|
|
where
|
|
printWarning (Just m, s) = liftIO $ hPutStrLn stderr $ show m ++ " " ++ s
|
|
printWarning (Nothing, s) = liftIO $ hPutStrLn stderr s
|
|
|
|
|
|
-- | Fail after an internal error.
|
|
dieInternal :: Monad m => ErrorReport -> m a
|
|
dieInternal (m,s) = error $ "\n\n" ++ (maybe "" show m) ++ "Internal error: " ++ s
|
|
|
|
-- | Extract a value from a Maybe type, dying with the given error if it's Nothing.
|
|
checkJust :: Die m => ErrorReport -> Maybe t -> m t
|
|
checkJust _ (Just v) = return v
|
|
checkJust err _ = dieReport err
|