#5254: usb library fails on Windows
---------------------------------+------------------------------------------
Reporter: basvandijk | Owner:
Type: bug | Status: new
Priority: low | Milestone: 7.6.1
Component: Compiler (FFI) | Version: 7.0.3
Keywords: | Os: Windows
Architecture: Unknown/Multiple | Failure: Runtime crash
Difficulty: | Testcase:
Blockedby: | Blocking:
Related: |
---------------------------------+------------------------------------------
Comment(by basvandijk):
Summarizing: executing the following isolated program with the argument
"fp" (for !ForeignPtr) gives an error and without it I get no error:
{{{
{-# LANGUAGE ForeignFunctionInterface #-}
module Main where
import Foreign
import Foreign.C.Types
import Control.Concurrent
import System.Environment
main :: IO ()
main = do
ctxPtr <- alloca $ \ctxPtrPtr -> do
_ <- c'libusb_init ctxPtrPtr
peek ctxPtrPtr
args <- getArgs
case args of
["fp"] -> do
fp <- newForeignPtr p'libusb_exit ctxPtr
threadDelay 1000000
print $ fp == fp
_ -> c'libusb_exit ctxPtr
data C'libusb_context = C'libusb_context
foreign import stdcall "libusb_init" c'libusb_init
:: Ptr (Ptr C'libusb_context) -> IO CInt
foreign import stdcall "&libusb_exit" p'libusb_exit
:: FunPtr (Ptr C'libusb_context -> IO ())
foreign import stdcall "libusb_exit" c'libusb_exit
:: Ptr C'libusb_context -> IO ()
}}}
Note that building the program with the new `win64_alpha1` GHC doesn't
produce the error. I only get warnings that the `stdcall` calling
convention is not supported. So I guess it then falls back to the `ccall`
calling convention which does work.
Make sure to give these flags to cabal when building the program:
* `--extra-include-dirs="...\libusb\include\libusb-1.0"`
* `--extra-lib-dirs="...\libusb\MinGW32\dll"` or: `--extra-lib-
dirs="...\libusb\MinGW64\dll"` when building with the new `win64_alpha1`
GHC.
and make sure the `libusb-1.0.dll` is in your working directory when
running the program.
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/5254#comment:4>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler
_______________________________________________
Glasgow-haskell-bugs mailing list
Glasgow-haskell-bugs@haskell.org
http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
