llvm library linking issues

[King Mir]

I'm trying to link make use of the llvm compiler libraries, but I can't get them to link to my program correctly.

#include <llvm/Constants.h>
#include <llvm/DerivedTypes.h>

int main(){
    llvm::APInt(1,0);
    return 0;
}

I get an error like:
undefined reference to `llvm::APInt::initSlowCase(unsigned int, unsigned long long, bool)
(this function is called by the inline APInt constructor)

The library seems to be found correctly; it doesn't give any other errors. Using nm I can see the mangled function initSlowCase exactly where I expect it to be (though I cannot verify that the mangling is correct). I'm out of ideas of that could be wrong.

I'm using kubuntu 12.04. Same error occurs with both clang++ and g++.

[CornedBee]

Only thing I can think of: are you sure your headers and libraries match? Are they from the exact same version of llvm? It could be that it picks up one of the two from an unexpected location.

[King Mir]

I'm sure that the intended header and library match, but I did previously install an earlier version of llvm. I uninstalled it before upgrading, but maybe that process left behind some artefacts. If only I could find them.

EDIT: I tried removing separately the include, and the library. In both cases if failed to find the necessary file. Which suggests it's looking at the right pair of files.

[CornedBee]

I suggest writing to the LLVM Developers Mailing List <[email protected]>. They probably can help you more.

By the way, to verify mangling, you can use c++filt. It's a little utility that should come with the GCC and Clang installs.