CODEWITHSUNDEEP
chaskellmingwldffi
Will
Will

Reputation: 321

ld error while building GD library for Haskell on Windows

When installing the Haskell GD package through cabal, on Windows (using MinGW), I get the following warnings:

Warning: resolving _gdImagePtrDestroyIfNotNull by linking to _gdImagePtrDestroyIfNotNull@4
Warning: resolving _gdImageCopyRotated90 by linking to _gdImageCopyRotated@36
Use --enable-stdcall-fixup to disable these warnings
Use --disable-stdcall-fixup to disable these fixups

Note that these are precisely the functions defined in gd-extras.
Then, when actually compiling a Haskell program which uses gd, I get the following errors:

Linking Main.exe ...
[...]\cabal\gd-3000.7.3\ghc-7.4.1/libHSgd-3000.7.3.a(Internal.o):fake:(.text+0x2211):undefined reference to 'gdImageCopyRotated90'
[...]\cabal\gd-3000.7.3\ghc-7.4.1/libHSgd-3000.7.3.a(Internal.o):fake:(.text+0x500a):undefined reference to 'gdImagePtrDestroyIfNotNull'
[...]
collect2: ld returned 1 exit status

I'm unable to figure out how to fix this — it's already taken me ages to get to this point, as I've had many more issues trying to get it working, but this seems like the final hurdle. I have tried enabling/disabling stdcall fixup, and also changing in which file these functions are defined (as gd-extras seemed to be a potential issue), but that hasn't adressed the issues.
Thanks for any help.

Upvotes: 0

Views: 239

Answers (1)

sclv
sclv

Reputation: 38891

You need to pass explicit linker flags to ghc, pointing to the library. The Haskell GD library is automatically linked, but the dll will not be linked as well unless you tell ghc about it. The stdcall-fixup errors are a red herring here.

Upvotes: 1

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