[LLVMdev] Unable to build PBQP/Graph.h with libc++

[David Blaikie]

On Sat, Oct 20, 2012 at 1:47 PM, Jordan Rose <jordan_rose at apple.com> wrote:
> Hi, everyone. Today I was trying to build LLVM with libc++ and C++11 enabled, and I ran into this:
>
> http://stackoverflow.com/questions/10065384/instantiation-of-a-list-with-an-incomplete-type-in-a-typedef
>
> Basically, PBQP/Graph.h forward-declares classes, then tries to get iterators for std::lists of those classes. This is technically undefined behavior. I tried fudging with the order of declarations for a while, but gave up after realizing there's not an easy way out.
>
> Is anyone else building LLVMCodeGen with libc++ and C++11? Is anyone else seeing this?

Yeah, I think Lang (author of PBQP) came across this at some point.
We've discussed it & we didn't immediately come up with any great idea
of how to solve it... certainly something that still needs some
thought (& ultimately, a fix ;))