[GHC] #13483: Can't allocate thunk for wcslen

25 Mar 2017

      #13483: Can't allocate thunk for wcslen
-------------------------------------+-------------------------------------
           Reporter:  NickSeagull    |             Owner:  (none)
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  Compiler       |           Version:  8.0.2
  (FFI)                              |
           Keywords:                 |  Operating System:  Windows
       Architecture:  x86_64         |   Type of failure:  Compile-time
  (amd64)                            |  crash or panic
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
-------------------------------------+-------------------------------------
 Hello,

 I'm trying to use the [https://sourceforge.net/projects/tinyfiledialogs
 tinyfiledialogs] library through the FFI, I've put the .h and .c files in
 a folder called "foreign" in the root of my project and configured cabal
 so it looks in this folder. The code for calling this function is as:

 {{{#!hs
 {-# LANGUAGE ForeignFunctionInterface #-}
 module Escri where

 import Foreign.C.String

 foreign import ccall "tinyfiledialogs.h tinyfd_messageBox" c_messageBox
     :: CString -> CString -> CString -> CString -> Int -> IO Int

 messageBox :: String -> String -> String -> String -> Int -> IO Bool
 messageBox title message dialogType iconType defaultButton = do
     cTitle <- newCString title
     cMessage <- newCString message
     cDialogType <- newCString dialogType
     cIconType <- newCString iconType
     result <- c_messageBox cTitle cMessage cDialogType cIconType
 defaultButton
     return (result == 1)
 }}}

 When trying to run GHCi for this project, I get the following error
 {{{
 Configuring GHCi with the following packages: escri
 GHCi, version 8.0.2: http://www.haskell.org/ghc/  :? for help
 ghc.EXE: internal error: Can't allocate thunk for wcslen
     (GHC version 8.0.2 for x86_64_unknown_mingw32)
     Please report this as a GHC bug:
 http://www.haskell.org/ghc/reportabug

 This application has requested the Runtime to terminate it in an unusual
 way.
 Please contact the application's support team for more information.
 }}}

 This only happens in Windows. In OSX I just get a linker error.

 If I try to make a call with stdcall, it tells:
 {{{
 C:\Users\Nick\Development\escri\src\Escri.hs:6:1: warning: [-Wunsupported-
 calling-conventions]
     * the 'stdcall' calling convention is unsupported on this platform,
       treating as ccall
     * When checking declaration:
         foreign import stdcall safe "static tinyfiledialogs.h
 tinyfd_messageBox" c_messageBox
           :: CString -> CString -> CString -> CString -> Int -> IO Int
 }}}

 Which is strange, because I'm on Windows.

 Thanks in advance.

--
Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13483
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