#7243: regression: acceptable foreign result types -------------------------------------+------------------------------------- Reporter: dmwit | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.10.1 Component: Compiler | Version: 7.6.1 (FFI) | Keywords: Resolution: | Architecture: x86_64 (amd64) Operating System: | Difficulty: Unknown Unknown/Multiple | Blocked By: Type of failure: GHC | Related Tickets: rejects valid program | Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Comment (by thomie): In commit 92587bfefea2b78f89bcdad27e0da5711463fd1b: {{{ Author: Simon Peyton Jones <> Date: Fri Jul 25 16:22:21 2014 +0100 Refactor FFI error messages This patch was provoked by Trac #5610, which I finally got a moment to look at. In the end I added a new data type ErrUtils.Validity, data Validity = IsValid -- Everything is fine | NotValid MsgDoc -- A problem, and some indication of why with some suitable combinators, and used it where appropriate (which touches quite a few modules). The main payoff is that error messages improve for FFI type validation. }}} The error message is now: {{{ $ ghc-7.9.20141121 test.hs [1 of 1] Compiling Foo ( test.hs, test.o ) test.hs:3:1: Unacceptable type in foreign declaration: One argument expected When checking declaration: foreign import ccall safe "wrapper" foo :: IO (FunPtr ()) }}} Only a regression test is missing. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/7243#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler