2008/11/13 Greg Fitzgerald :

Do you know how I can fix these linker errors?

C:\projects\fun>cat HelloWorld.hs

import Graphics.Rendering.OpenGL import Graphics.UI.GLUT main = do (progname, _) <- getArgsAndInitialize createWindow "Hello World" displayCallback $= clear [ColorBuffer] mainLoop

C:\projects\fun>ls lib GlU32.Lib glut32.lib OpenGL32.Lib glut.def glut32.dll

C:\projects\fun>ghc -Llib -lglut32 -lglu32 -lopengl32 HelloWorld.hs --make Linking HelloWorld.exe ... C:\Program Files\Haskell\GLUT-2.1.1.2\ghc-6.10.1/libHSGLUT-2.1.1.2.a(Begin.o):fake:(.text+0x1cb): undefined reference to `glutGet' [...]

Thanks, Greg

I'm assuming this is on Windows because of C:\... These kinds of linker errors happened to me when I built libHSGLUT with a wrong type of calling convention (by accident). There are two callconvs, and they are called stdcall and ccall on the Haskell side. The 'runhaskell setup configure' step is supposed to detect the correct one to use, so you should run it and then grep for lines with CALLCONV. They should say stdcall on Windows. If you find them saying ccall, that's likely the cause of all the linker errors. (Most Windows dynamic libraries use stdcall, but for extra configuration fun OpenAL uses ccall.) If this is the problem, you can change the offending ccall in the configuration files to stdcall and rebuild the library. Grepping for CALLCONV will also show the places you need to change this way. In my case the wrong configuration came from using the sh program from Cygwin. With the MSYS variety there was no problem. To be exact, it came down to the $host variable checked by the configuration script. Pekka