#14624: HEAD panic in ghc:DsForeign: toCType -------------------------------------+------------------------------------- Reporter: tianxiaogu | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.2 Keywords: | Operating System: Linux Architecture: x86_64 | Type of failure: Compile-time (amd64) | crash or panic Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- The following program crashes in 8.2.2 and HEAD (8.5.20171228). {{{#!hs {-# LANGUAGE ForeignFunctionInterface, CApiFFI, GHCForeignImportPrim, QuasiQuotes, TemplateHaskell, JavaScriptFFI, MagicHash, UnliftedFFITypes #-} module TH_foreignCallingConventions where import GHC.Prim import Control.Applicative import Language.Haskell.TH import System.IO import Foreign.Ptr $( do let fi cconv safety lbl name ty = ForeignD (ImportF cconv safety lbl name ty) dec1 <- fi CCall Interruptible "&" (mkName "foo") <$> [t| Ptr () |] dec2 <- fi CApi Safe "bar" (mkName "bar") <$> [t| Int# -> Int# |] -- the declarations below would result in warnings or errors when returned dec3 <- fi CApi Unsafe "baz" (mkName "baz") <$> [t| Double -> IO () |] dec4 <- fi StdCall Safe "bay" (mkName "bay") <$> [t| (Int -> Bool) -> IO Int |] dec5 <- fi JavaScript Unsafe "bax" (mkName "bax") <$> [t| Ptr Int -> IO String |] runIO $ mapM_ (putStrLn . pprint) [dec1, dec2, dec3, dec4, dec5] >> hFlush stdout return [dec1, dec2] ) }}} This program is derived by mutating test TH_foreignCallingConventions.hs. {{{#!diff diff --git a/testsuite/tests/th/TH_foreignCallingConventions.hs b/testsuite/tests/th/TH_foreignCallingConventions.hs index ee39510..16789af 100644 --- a/testsuite/tests/th/TH_foreignCallingConventions.hs +++ b/testsuite/tests/th/TH_foreignCallingConventions.hs @@ -13,7 +13,7 @@ import Foreign.Ptr $( do let fi cconv safety lbl name ty = ForeignD (ImportF cconv safety lbl name ty) dec1 <- fi CCall Interruptible "&" (mkName "foo") <$> [t| Ptr () |] - dec2 <- fi Prim Safe "bar" (mkName "bar") <$> [t| Int# -> Int# |] + dec2 <- fi CApi Safe "bar" (mkName "bar") <$> [t| Int# -> Int# |] -- the declarations below would result in warnings or errors when returned dec3 <- fi CApi Unsafe "baz" (mkName "baz") <$> [t| Double -> IO () |] dec4 <- fi StdCall Safe "bay" (mkName "bay") <$> [t| (Int -> Bool) -> IO Int |] }}} Log: {{{ foreign import capi safe "bar" bar :: GHC.Prim.Int# -> GHC.Prim.Int# foreign import capi unsafe "baz" baz :: GHC.Types.Double -> GHC.Types.IO () foreign import stdcall safe "bay" bay :: (GHC.Types.Int -> GHC.Types.Bool) -> GHC.Types.IO GHC.Types.Int foreign import javascript unsafe "bax" bax :: GHC.Ptr.Ptr GHC.Types.Int -> GHC.Types.IO GHC.Base.String ghc: panic! (the 'impossible' happened) (GHC version 8.5.20171228 for x86_64-unknown-linux): toCType Int# Call stack: CallStack (from HasCallStack): callStackDoc, called at compiler/utils/Outputable.hs:1150:37 in ghc:Outputable pprPanic, called at compiler/deSugar/DsForeign.hs:730:17 in ghc:DsForeign Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14624 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler