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| author | Ben Gamari <ben@smart-cactus.org> | 2015-11-26 12:12:32 +0100 |
|---|---|---|
| committer | Ben Gamari <ben@smart-cactus.org> | 2015-11-26 14:48:51 +0100 |
| commit | ba14f04dae398c102209e3374bea882ebf823257 (patch) | |
| tree | c0eafcf10be09af7c1159279b2baaafdc19a1627 /libraries/base/GHC/ExecutionStack.hs | |
| parent | 1712a9ed333dfa2fc9ce7d55acab08a8d278fb5b (diff) | |
| download | haskell-ba14f04dae398c102209e3374bea882ebf823257.tar.gz | |
Libdw: Handle failure to grab session for location lookup
This one slipped through testing.
Diffstat (limited to 'libraries/base/GHC/ExecutionStack.hs')
| -rw-r--r-- | libraries/base/GHC/ExecutionStack.hs | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/libraries/base/GHC/ExecutionStack.hs b/libraries/base/GHC/ExecutionStack.hs index 245b996467..11f8c9e50a 100644 --- a/libraries/base/GHC/ExecutionStack.hs +++ b/libraries/base/GHC/ExecutionStack.hs @@ -36,14 +36,15 @@ module GHC.ExecutionStack ( , showStackTrace ) where +import Control.Monad (join) import GHC.ExecutionStack.Internal -- | Get a trace of the current execution stack state. -- -- Returns @Nothing@ if stack trace support isn't available on host machine. getStackTrace :: IO (Maybe [Location]) -getStackTrace = fmap stackFrames `fmap` collectStackTrace +getStackTrace = (join . fmap stackFrames) `fmap` collectStackTrace -- | Get a string representation of the current execution stack state. showStackTrace :: IO (Maybe String) -showStackTrace = fmap (flip showStackFrames "") `fmap` getStackTrace +showStackTrace = fmap (\st -> showStackFrames st "") `fmap` getStackTrace |