ghc-mod/Language/Haskell/GhcMod/Error.hs
Daniel Gröber 82bb0090c0 Refactoring to use cabal-helper-wrapper
This turned out to be quite involved but save for this huge commit it's
actually quite awesome and squashes quite a few bugs and nasty
problems (hopefully). Most importantly we now have native cabal
component support without the user having to do anything to get it!

To do this we traverse imports starting from each component's
entrypoints (library modules or Main source file for executables) and
use this information to find which component's options each module will
build with. Under the assumption that these modules have to build with
every component they're used in we can now just pick one.

Quite a few internal assumptions have been invalidated by this
change. Most importantly the runGhcModT* family of cuntions now change
the current working directory to `cradleRootDir`.
2015-03-05 17:35:24 +01:00

189 lines
6.4 KiB
Haskell

-- ghc-mod: Making Haskell development *more* fun
-- Copyright (C) 2015 Daniel Gröber <dxld ÄT darkboxed DOT org>
--
-- This program is free software: you can redistribute it and/or modify
-- it under the terms of the GNU Affero General Public License as published by
-- the Free Software Foundation, either version 3 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 Affero General Public License for more details.
--
-- You should have received a copy of the GNU Affero General Public License
-- along with this program. If not, see <http://www.gnu.org/licenses/>.
{-# LANGUAGE ExistentialQuantification #-}
module Language.Haskell.GhcMod.Error (
GhcModError(..)
, GMConfigStateFileError(..)
, GmError
, gmeDoc
, ghcExceptionDoc
, liftMaybe
, overrideError
, modifyError
, modifyError'
, modifyGmError
, tryFix
, GHandler(..)
, gcatches
, module Control.Monad.Error
, module Control.Exception
) where
import Control.Arrow
import Control.Exception
import Control.Monad.Error
import qualified Data.Set as Set
import Data.List
import Data.Version
import System.Process (showCommandForUser)
import Text.PrettyPrint
import Text.Printf
import Exception
import Panic
import Config (cProjectVersion, cHostPlatformString)
import Paths_ghc_mod (version)
import Language.Haskell.GhcMod.Types
import Language.Haskell.GhcMod.Pretty
type GmError m = MonadError GhcModError m
gmCsfeDoc :: GMConfigStateFileError -> Doc
gmCsfeDoc GMConfigStateFileNoHeader = text $
"Saved package config file header is missing. "
++ "Try re-running the 'configure' command."
gmCsfeDoc GMConfigStateFileBadHeader = text $
"Saved package config file header is corrupt. "
++ "Try re-running the 'configure' command."
gmCsfeDoc GMConfigStateFileNoParse = text $
"Saved package config file body is corrupt. "
++ "Try re-running the 'configure' command."
gmCsfeDoc GMConfigStateFileMissing = text $
"Run the 'configure' command first."
-- gmCsfeDoc (ConfigStateFileBadVersion oldCabal oldCompiler _) = text $
-- "You need to re-run the 'configure' command. "
-- ++ "The version of Cabal being used has changed (was "
-- ++ display oldCabal ++ ", now "
-- ++ display currentCabalId ++ ")."
-- ++ badCompiler
-- where
-- badCompiler
-- | oldCompiler == currentCompilerId = ""
-- | otherwise =
-- " Additionally the compiler is different (was "
-- ++ display oldCompiler ++ ", now "
-- ++ display currentCompilerId
-- ++ ") which is probably the cause of the problem."
gmeDoc :: GhcModError -> Doc
gmeDoc e = case e of
GMENoMsg ->
text "Unknown error"
GMEString msg ->
text msg
GMECabalConfigure msg ->
text "Configuring cabal project failed: " <> gmeDoc msg
GMECabalFlags msg ->
text "Retrieval of the cabal configuration flags failed: " <> gmeDoc msg
GMECabalComponent cn ->
text "Cabal component " <> quotes (gmComponentNameDoc cn)
<> text " could not be found."
GMECabalCompAssignment ctx ->
text "Could not find a consistent component assignment for modules:" $$
(nest 4 $ foldr ($+$) empty $ map ctxDoc ctx) $$
empty $$
text "Try this and that"
where
ctxDoc = moduleDoc *** compsDoc
>>> first (<> colon) >>> uncurry (flip hang 4)
moduleDoc (Left fn) =
text "File " <> quotes (text fn)
moduleDoc (Right mdl) =
text "Module " <> quotes (text $ moduleNameString mdl)
compsDoc sc | Set.null sc = text "has no known components"
compsDoc sc = fsep $ punctuate comma $
map gmComponentNameDoc $ Set.toList sc
GMEProcess cmd args emsg -> let c = showCommandForUser cmd args in
case emsg of
Right err ->
text (printf "Launching system command `%s` failed: " c)
<> gmeDoc err
Left (_out, _err, rv) -> text $
printf "Launching system command `%s` failed (exited with %d)" c rv
GMENoCabalFile ->
text "No cabal file found."
GMETooManyCabalFiles cfs ->
text $ "Multiple cabal files found. Possible cabal files: \""
++ intercalate "\", \"" cfs ++"\"."
GMECabalStateFile csfe ->
gmCsfeDoc csfe
ghcExceptionDoc :: GhcException -> Doc
ghcExceptionDoc e@(CmdLineError _) =
text $ "<command line>: " ++ showGhcException e ""
ghcExceptionDoc (UsageError str) = strDoc str
ghcExceptionDoc (Panic msg) = vcat $ map text $ lines $ printf "\
\GHC panic! (the 'impossible' happened)\n\
\ ghc-mod version %s\n\
\ GHC library version %s for %s:\n\
\ %s\n\
\\n\
\Please report this as a bug: %s\n"
gmVer ghcVer platform msg url
where
gmVer = showVersion version
ghcVer = cProjectVersion
platform = cHostPlatformString
url = "https://github.com/kazu-yamamoto/ghc-mod/issues" :: String
ghcExceptionDoc e = text $ showGhcException e ""
liftMaybe :: MonadError e m => e -> m (Maybe a) -> m a
liftMaybe e action = maybe (throwError e) return =<< action
overrideError :: MonadError e m => e -> m a -> m a
overrideError e action = modifyError (const e) action
modifyError :: MonadError e m => (e -> e) -> m a -> m a
modifyError f action = action `catchError` \e -> throwError $ f e
infixr 0 `modifyError'`
modifyError' :: MonadError e m => m a -> (e -> e) -> m a
modifyError' = flip modifyError
modifyGmError :: (MonadIO m, ExceptionMonad m)
=> (GhcModError -> GhcModError) -> m a -> m a
modifyGmError f a = gcatch a $ \(ex :: GhcModError) -> liftIO $ throwIO (f ex)
tryFix :: MonadError e m => m a -> (e -> m ()) -> m a
tryFix action f = do
action `catchError` \e -> f e >> action
data GHandler m a = forall e . Exception e => GHandler (e -> m a)
gcatches :: ExceptionMonad m => m a -> [GHandler m a] -> m a
gcatches io handlers = io `gcatch` gcatchesHandler handlers
gcatchesHandler :: ExceptionMonad m => [GHandler m a] -> SomeException -> m a
gcatchesHandler handlers e = foldr tryHandler (liftIO $ throw e) handlers
where tryHandler (GHandler handler) res
= case fromException e of
Just e' -> handler e'
Nothing -> res