[PATCH] D20119: [libunwind] Improve unwinder stack usage

[Jonathan Roelofs via cfe-commits]

jroelofs added a comment.

In http://reviews.llvm.org/D20119#437191, @rmaprath wrote:

> In http://reviews.llvm.org/D20119#436849, @jroelofs wrote:
>
> > In http://reviews.llvm.org/D20119#431997, @rmaprath wrote:
> >
> > > Addressing review comments from @jroelofs:
> > >
> > > - Moved the assertion in `libunwind.cpp` back to `UnwindCursor.cpp` where it really belogs.
> > >
> > >   @jroelofs: I just realized that, with this new native-only build of `libunwind`, users of `libunwind.h` would have to explicitly `#define` the flag `_LIBUNWIND_IS_NATIVE_ONLY` in order to get the header in-sync with the library. I can't see an immediate problem if they don't define that flag though, it's just that they'll end up passing larger buffers than the library needs. Do you see a problem here?
> >
> >
> > I'm not convinced it's a problem, (though possibly performance left on the table)...
> >
> > > 'libc++' uses a `__config_site` mechanism to wire the cmake build options into the `__config` header. We can implement a similar mechanism in `libunwind`, not sure if that's necessary here.
> >
> >
> > I think that's the right way to go.
> >
> > Jon
> >
> > > WDYT?
> >
> > > 
> >
> > > Thanks.
> >
> > > 
> >
> > > / Asiri
> >
>
>
> Apologies, it looks like we don't have any targets for installing `libunwind.h` header (or any other headers from `libunwind` project for that matter). I think this means we use `libunwind.h` only for building libunwind+libcxxabi libraries, and there's no need to explicitly adjust `libunwind.h` header as it is not used from outside as-is. Hope this makes sense.
>
> OK to commit? Sorry for the diversion.


Ah, ok. LGTM then!

Jon

> / Asiri





http://reviews.llvm.org/D20119