From 30d25dd856cf539ca0dc798310180007abee7b6b Mon Sep 17 00:00:00 2001
From: Iustin Pop <iustin@google.com>
Date: Sun, 25 Mar 2012 16:26:02 +0200
Subject: [PATCH] Switch to new-style exception handling
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Currently, we're using Prelude.catch to handle I/O errors in
htools. This style of error handling has been deprecated for a while,
but it still used to work without warnings.
However, the GHC release 7.4 has started to emit deprecation warnings
for it, so we change to the Control.Exception module; the code is a
bit less clean since we only care about I/O errors (but
Control.Exception deals with other error types too), so we have to
filter the exceptions.
Note that the new style exception handling is not really "new"; it has
existed since at least GHC 6.12, which is our oldest supported
compiler.
Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: RenΓ© Nussbaumer <rn@google.com>
---
htools/Ganeti/HTools/ExtLoader.hs | 4 +++-
htools/Ganeti/HTools/Rapi.hs | 5 ++++-
htools/htools.hs | 7 ++++++-
3 files changed, 13 insertions(+), 3 deletions(-)
diff --git a/htools/Ganeti/HTools/ExtLoader.hs b/htools/Ganeti/HTools/ExtLoader.hs
index 2defadecf..bd258f5f3 100644
--- a/htools/Ganeti/HTools/ExtLoader.hs
+++ b/htools/Ganeti/HTools/ExtLoader.hs
@@ -34,7 +34,9 @@ module Ganeti.HTools.ExtLoader
) where
import Control.Monad
+import Control.Exception
import Data.Maybe (isJust, fromJust)
+import Prelude hiding (catch)
import System.FilePath
import System.IO
import Text.Printf (hPrintf)
@@ -53,7 +55,7 @@ import Ganeti.HTools.Utils (sepSplit, tryRead, exitIfBad, exitWhen)
-- | Error beautifier.
wrapIO :: IO (Result a) -> IO (Result a)
-wrapIO = flip catch (return . Bad . show)
+wrapIO = flip catch (\e -> return . Bad . show $ (e::IOException))
-- | Parses a user-supplied utilisation string.
parseUtilisation :: String -> Result (String, DynUtil)
diff --git a/htools/Ganeti/HTools/Rapi.hs b/htools/Ganeti/HTools/Rapi.hs
index d52abab1c..710bfbb6f 100644
--- a/htools/Ganeti/HTools/Rapi.hs
+++ b/htools/Ganeti/HTools/Rapi.hs
@@ -30,6 +30,7 @@ module Ganeti.HTools.Rapi
, parseData
) where
+import Control.Exception
import Data.List (isPrefixOf)
import Data.Maybe (fromMaybe)
#ifndef NO_CURL
@@ -37,6 +38,7 @@ import Network.Curl
import Network.Curl.Types ()
#endif
import Control.Monad
+import Prelude hiding (catch)
import Text.JSON (JSObject, fromJSObject, decodeStrict)
import Text.JSON.Types (JSValue(..))
import Text.Printf (printf)
@@ -83,7 +85,8 @@ getUrl url = do
-- | Helper to convert I/O errors in 'Bad' values.
ioErrToResult :: IO a -> IO (Result a)
ioErrToResult ioaction =
- catch (ioaction >>= return . Ok) (return . Bad . show)
+ catch (ioaction >>= return . Ok)
+ (\e -> return . Bad . show $ (e::IOException))
-- | Append the default port if not passed in.
formatHost :: String -> String
diff --git a/htools/htools.hs b/htools/htools.hs
index f35c18cdf..2e847d7f2 100644
--- a/htools/htools.hs
+++ b/htools/htools.hs
@@ -25,10 +25,14 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
module Main (main) where
+import Control.Exception
+import Control.Monad (guard)
import Data.Char (toLower)
+import Prelude hiding (catch)
import System.Environment
import System.Exit
import System.IO
+import System.IO.Error (isDoesNotExistError)
import Ganeti.HTools.Utils
import Ganeti.HTools.CLI (parseOpts)
@@ -47,7 +51,8 @@ usage name = do
main :: IO ()
main = do
- binary <- getEnv "HTOOLS" `catch` const getProgName
+ binary <- catchJust (guard . isDoesNotExistError)
+ (getEnv "HTOOLS") (const getProgName)
let name = map toLower binary
boolnames = map (\(x, y) -> (x == name, Just y)) personalities
case select Nothing boolnames of
--
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