[LLVMdev] VMKit build problems; can't use LLVM3.4.2 ?

[Renato Golin]

On 21 July 2014 21:33, Brian Faull <bfaull at cog-e.com> wrote:
> Incidentally, this seems to be the same behavior/problem as reported on 20 January 2014 by neoedmund (http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-January/069558.html), which is solved by building using LLVM3.3 (no response seen).

Hi Brian,

It's common for some projects to attach themselves to a specific
version of LLVM when the team doesn't have time to merge their code to
trunk every other week, which can be very costly in the long term.
However, any project that aims to be relevant in the LLVM community
has to follow trunk, not a specific release, not even the current
release. On projects whose aim is to present a proof-of-concept or to
focus on a completely unrelated issue (VMKit, LLVMpipe), this seems to
be the choice to stick to a release or even an SVN revision number.
But for any compilation tool, it should never be.

LLVM APIs do change considerably, even between a few commits apart.
So, even if you support 3.5svn trunk, you can become obsolete in a
matter of weeks. This dependency cannot be solved by LLVM supporting
old APIs, or the code would have more legacy than features, and has to
become a motto of the side projects themselves. Thus, unless VMKit
developers are willing to follow trunk and have buildbots following
the rest, it won't happen.

Of course, as with any open source project, *you* could be the person
to drive this, in case other VMKit developers are unwilling to take
the extra work. :)

cheers,
--renato